CN120438747A

CN120438747A - Laser heating system and method for flip chip welding and repair

Info

Publication number: CN120438747A
Application number: CN202510941833.6A
Authority: CN
Inventors: 毛洪波; 请求不公布姓名
Original assignee: Zhuhai Maishe Technology Co ltd
Current assignee: Zhuhai Maishe Technology Co ltd
Priority date: 2025-07-09
Filing date: 2025-07-09
Publication date: 2025-08-08
Anticipated expiration: 2045-07-09
Also published as: CN120438747B

Abstract

The present invention discloses a laser heating system and method for flip-chip welding and repair, belonging to the technical field of electronic components. The system includes: a solder paste adjustment module, a chip welding module, and a welding repair module; a solder paste abnormality assessment is performed on the solder pad after solder paste printing based on solder paste quality parameters, and based on the obtained solder paste abnormality assessment results, it is determined whether to perform dynamic printing adjustment; after flip-chip bonding, it is determined whether to perform dynamic bonding compensation based on the bonding offset and rotational deviation between the flip-chip and the solder pad; after flip-chip bonding using a flip-chip welding device, the flip-chip welding effect is quantitatively evaluated based on welding accuracy parameters, and based on the quantitative evaluation results, it is determined whether to use the flip-chip welding device to repair the flip-chip. This system achieves precise control of temperature and heat distribution during the welding process through laser heating, thereby improving the quality of flip-chip bonding and repair.

Description

Laser heating system and method for flip chip welding and repairing

Technical Field

The invention relates to the technical field of electronic components, in particular to a laser heating system and a laser heating method for flip chip welding and repairing.

Background

In the existing flip chip welding, a process of brushing tin paste and then heating the tin paste by a reflow oven is adopted, a substrate bonding pad is aligned with the position of an opening of a steel mesh in a steel mesh printing mode, the tin paste pile is horizontally arranged at the upper end of the steel mesh, the thixotropic property of the tin paste can enable the tin paste to keep the shape in the opening of the steel mesh for a short time, the tin paste can not naturally drop down due to gravity, the tin paste is pressed from the upper side of the tin paste by a scraper and flows into the opening of the steel mesh, the tin paste is remained on the substrate bonding pad due to adhesion, the steel mesh needs to be separated from the substrate vertically upwards according to the separation speed, the tin paste is separated from the opening of the steel mesh and remains on the bonding pad to form uniform tin paste points, then the flip chip bonding point and the tin paste points are aligned and bonded to form a component, the component is heated by the reflow oven, the temperature is slowly increased to avoid the thermal shock, the tin paste begins to melt in a constant temperature stage, the tin paste begins to flow under a constant temperature stage, the tin paste is completely melted to form a liquid molten pool under the reflow stage, the tin paste is in a liquid state (namely the solder ball on a chip) is contacted with the tin paste under the pressure to form a liquid state bonding interface, the liquid solder paste, the temperature is gradually reduced in a cooling stage, and the cooling interface is formed, and the solder pool is cooled.

Although the reflow soldering is a very mature soldering process, the reflow soldering is not suitable for rapid and small-batch production due to the problems of large occupied area, high energy consumption, long preheating time and the like, and is not suitable for the production process of some temperature-sensitive device products, and the product needing local heating soldering is mostly required to repair soldering at present, so that the efficiency is low and the yield is not high. For example, in the production process of an LED (LIGHT EMITTING Diode), after the chips are attached, the chips are solidified by reflow soldering and tin melting, but in the case of small-batch production, the reflow soldering cost is very high because of long preheating time and high cost for starting the reflow soldering.

For example, a flip chip and a soldering method thereof disclosed in patent publication No. CN108288591B comprise providing a chip provided with metal bumps capable of generating induced current under the action of an alternating magnetic field, flip-chip mounting the chip on a substrate, placing the mounted chip and the substrate in the alternating magnetic field to generate induced current in the metal bumps, and melting the metal bumps to form soldering by utilizing the thermal effect of the induced current.

The method for removing and repairing the Mini LED chip comprises the steps of placing a chip, enabling a chip substrate to be located at the upper end of a chip substrate, utilizing high-energy pulse laser to bombard the chip substrate, enabling the Mini LED chip to break at a welding position under the action of shock wave oscillation and fall off from the chip substrate and be separated from the chip substrate instantaneously by shock waves generated by high-temperature plasma generated by the action of laser pulse and a substrate surface material, and enabling the Mini LED chip to be focused by the laser.

The above technology has at least the following technical problems:

In the prior art, in the welding process, because the chip welding precision requirement is extremely high, when the chip size is too small, the chip position can deviate from the center of a solder paste point, the condition of insufficient welding spot contact area appears, thereby influencing welding quality, in the process of repairing the welding spot with poor welding effect caused by the undersize of the chip, the prior art utilizes a reflow soldering table to remove abnormal chips and replace chips by welding, because a manual operation tool is difficult to accurately position and repair, the alignment deviation or the uneven thermal stress is easily caused, thereby influencing the quality of repairing the welding spot, and the problem of poor flip chip repairing effect exists.

Disclosure of Invention

According to the invention, the problems that in the welding process, due to extremely high chip welding precision requirement and poor welding spot contact area caused by the fact that the chip position possibly deviates from the center of a solder paste point when the chip size is too small in the prior art, the welding quality is affected, and meanwhile, in the process of repairing the welding spots with poor welding effect caused by the fact that the chip size is too small, the abnormal chip is removed and the chip is replaced by using a reflow soldering table in the prior art, due to the fact that a manual operation tool is difficult to accurately position and repair, alignment deviation or uneven thermal stress is easily caused, the quality of the repairing welding spots is affected, and the repairing effect of the flip chip is poor are solved, and the improvement of the welding and repairing quality of the flip chip is realized.

The invention provides a laser heating system for flip chip welding and repairing, which comprises a solder paste adjusting module, a chip welding module, a welding repairing module and a chip welding database, wherein the solder paste adjusting module is used for carrying out solder paste abnormal evaluation on a solder pad after solder paste printing according to solder paste quality parameters, judging whether printing dynamic adjustment is carried out or not based on an obtained solder paste abnormal evaluation result, the chip welding module is used for judging whether dynamic lamination compensation is carried out or not according to lamination offset and rotation offset of a flip chip and the solder pad after the flip chip is laminated, the welding repairing module carries out flip chip welding by utilizing a temperature probe, a temperature controller and a laser, carries out quantitative evaluation on the welding effect of the flip chip according to welding precision parameters after the flip chip welding, and judges whether flip chip repairing is carried out by utilizing the temperature probe, the temperature controller and the laser based on the quantitative evaluation result.

The invention also provides a laser heating method for flip chip welding and repairing, which comprises the steps of carrying out abnormal solder paste assessment on a solder pad after solder paste printing according to solder paste quality parameters, judging whether to carry out printing dynamic adjustment or not based on the obtained abnormal solder paste assessment result, judging whether to carry out dynamic lamination compensation or not according to lamination offset and rotation offset of a flip chip and the solder pad after lamination of the flip chip, carrying out flip chip welding by using a temperature probe, a temperature controller and a laser, carrying out quantitative assessment on the welding effect of the flip chip according to welding precision parameters after the flip chip welding, and judging whether to carry out flip chip repairing by using the temperature probe, the temperature controller and the laser based on the quantitative assessment result.

One or more technical solutions provided in the embodiments of the present application at least have the following technical effects or advantages:

1. According to the method, the solder paste anomaly evaluation is carried out on the solder paste after the solder paste printing according to the solder paste quality parameters, the printing quality of the solder paste in the printing process can be effectively identified, the scraper pressure and the demolding speed in the solder paste printing process can be dynamically regulated based on the solder paste anomaly evaluation result, the printing effect of the solder paste can be directly controlled, the uniformity of the solder paste thickness distribution is ensured, the influence of poor printing quality on the welding quality is avoided, then the position and the angle of the flip chip are optimized based on the bonding offset and the rotation offset of the flip chip and the solder paste, the mounting precision of the flip chip and the solder paste is improved, the welding defect caused by the mounting position error is reduced, finally the welding effect of the flip chip is quantitatively evaluated through the welding precision parameters, the welding quality of the flip chip can be accurately judged, the welding defect can be timely found and corrected, the accurate control of the temperature and the heat distribution in the welding process of the flip chip is realized, and the welding reliability and the quality of the flip chip are improved.

2. According to the method, the abnormal quantitative index of the solder paste is obtained through comprehensive analysis of the quality parameters of the solder paste, quantitative evaluation can be provided for the quality of the solder paste, whether printing dynamic adjustment is carried out or not is judged based on the abnormal quantitative index of the solder paste, the condition of excessive or insufficient solder paste can be detected rapidly, the pressure of a scraper is dynamically adjusted according to the abnormal quantitative index of the solder paste, the printing quantity of the solder paste can be directly controlled, the conditions of welding defects and poor welding caused by excessive solder paste are avoided, the accuracy and uniformity of the solder paste quantity are ensured, when the solder paste volume is in a standard range, the system improves the uniform distribution and the demolding effect of the solder paste through dynamic adjustment of the demolding speed, the stable release of the solder paste on a bonding pad is ensured, the printing quality is improved, and the condition of poor contact caused by uneven solder paste in the flip chip bonding process is avoided.

3. The invention can timely find the deviation of the chip and the bonding pad by monitoring the attaching deviation and the rotating deviation in real time and dynamically compensate based on the deviation, when the attaching deviation exceeds the corresponding threshold value, the system can automatically adjust the position of the chip to ensure the accurate butt joint of the chip and the bonding pad, when the rotating deviation exceeds the corresponding threshold value, the system can dynamically adjust the compensation angle to avoid poor contact or welding defect caused by the rotating deviation, and the accurate butt joint of the chip and the bonding pad can be effectively ensured, thereby improving the quality and stability of welding.

Drawings

Fig. 1 is a schematic structural diagram of a laser heating system for flip chip bonding and repair according to an embodiment of the present application.

Fig. 2 is a flowchart of a flip chip bonding apparatus according to an embodiment of the present application.

Fig. 3 is a laser path combination diagram provided by an embodiment of the present application, in the diagram, 1 is a laser, 2 is a collimating lens, 3 is a micro lens array, 4 is a focusing lens, 5 is a flip chip and a bonding pad, 6 is a CCD camera, and 7 is a temperature probe.

Fig. 4 is a block diagram of a unidirectional uniform spot-changing system according to an embodiment of the present application, in which fig. 8 is a collimator lens, 9 and 10 are two cylindrical microlenses, and 11 and 12 are two focusing lenses.

Fig. 5 is a uniform spot diagram of a unidirectional uniform spot-changing system according to an embodiment of the present application.

Fig. 6 is a light spot variation diagram of a unidirectional uniform spot-changing system according to an embodiment of the present application.

Fig. 7 is a schematic diagram of a unidirectional uniform speckle-changing system according to an embodiment of the application.

Fig. 8 is a diagram of a laser heating head according to an embodiment of the present application, in which 13 is a collimator lens, 14 is a first cylindrical microlens, 15 is a second cylindrical microlens, 16 is a third cylindrical microlens, 17 is a fourth cylindrical microlens, 18 is a first focusing lens, and 19 is a second focusing lens.

Fig. 9 is a diagram of a uniform spot of a laser heating head according to an embodiment of the present application.

Fig. 10 is a light spot variation diagram of a laser heating head according to an embodiment of the present application.

Fig. 11 is a schematic diagram of a dynamic adjustment of printing mind according to an embodiment of the present application.

Fig. 12 is a flowchart of a laser heating method for flip chip bonding and repair according to an embodiment of the present application.

Detailed Description

According to the embodiment of the application, the problems that in the welding process, due to extremely high requirements on welding precision of a chip, the position of the chip possibly deviates from the center of a solder paste point when the size of the chip is too small and the contact area of a welding spot is insufficient in the welding process in the prior art are solved, so that the welding quality is affected, meanwhile, in the process of repairing a welding spot with poor welding effect caused by the undersize of the chip, an abnormal chip and a welding replacement chip are removed by using a reflow soldering table in the prior art, due to the fact that a manual operation tool is difficult to accurately position and repair, the quality of a repairing welding spot is affected easily due to uneven positioning and thermal stress, the problem that the repairing effect of the flip chip is poor exists, the abnormal evaluation of the solder paste is carried out on the welding spot after the solder paste is carried out according to the quality parameters of the solder paste, whether the printing dynamic adjustment is carried out or not is judged based on the obtained abnormal evaluation result of the solder paste, whether the dynamic bonding compensation is carried out according to the bonding offset quantity and the rotation offset quantity of the bonding of the flip chip and the bonding pad after the flip chip is bonded, the flip chip is welded by using a temperature probe, a temperature controller and a laser chip is carried out flip chip bonding, the flip chip is carried out according to the welding quality, the temperature quality is quantitatively, the temperature is controlled by using the temperature controller and the temperature controller is used for the temperature controller to quantitatively controlling the temperature feedback welding quality of the temperature sensor and the temperature controller is used for the temperature controller to realize the temperature feedback adjustment and the temperature quality control and the temperature quality is quantized and the temperature controller is used for the temperature control and the temperature quality is quantized and the temperature control of the temperature device is used for the temperature control and the repair process.

The technical scheme in the embodiment of the application is to solve the problems that in the welding process, due to extremely high chip welding precision requirement, when the chip size is too small, the chip position possibly deviates from the center of a solder paste point, and the contact area of a welding spot is insufficient, thereby influencing the welding quality, and simultaneously in the repairing process of the welding spot with poor welding effect caused by the undersize of the chip, the prior art utilizes a reflow soldering table to remove an abnormal chip and replace the chip by welding, and because a manual operation tool is difficult to accurately position and repair, the alignment deviation or the uneven thermal stress are easily caused, thereby influencing the quality of the repairing welding spot, and the repairing effect of the flip chip is poor, and the overall thinking is as follows:

The method comprises the steps of dynamically evaluating and adjusting solder paste quality parameters, flip chip attaching precision and welding precision parameters, ensuring the accuracy of flip chip welding and repairing quality, firstly carrying out abnormal evaluation of solder paste according to the solder paste quality parameters, judging whether dynamic adjustment is needed in a printing process, optimizing scraper pressure and demolding speed to improve uniformity of solder paste thickness distribution, then judging whether dynamic attaching compensation is carried out in the flip chip attaching process according to attaching offset and rotating offset of a chip and a bonding pad, ensuring accurate butt joint of the chip position and angle, improving attaching precision, finally carrying out welding effect evaluation according to the welding precision parameters after welding is finished by using a flip chip welding device, judging whether flip chip repairing is needed, further optimizing welding effect, and realizing high-efficiency and high-precision control of temperature and heat distribution in the whole flip chip welding and repairing process based on a laser heating method.

In order to better understand the above technical solutions, the following detailed description will refer to the accompanying drawings and specific embodiments.

The laser heating system for flip chip welding and repairing comprises a solder paste adjusting module, a chip welding module, a welding repairing module and a chip welding database, wherein the solder paste adjusting module is used for carrying out solder paste abnormal assessment on a solder pad after solder paste printing according to solder paste quality parameters, judging whether printing dynamic adjustment is carried out or not based on the obtained solder paste abnormal assessment results, dynamically setting the pressure and demolding speed of a scraper in the next solder paste printing process to improve uniformity of solder paste thickness distribution, the chip welding module is used for judging whether dynamic lamination compensation is carried out or not according to lamination offset and rotation offset of a flip chip and a solder pad after the flip chip is laminated, dynamically adjusting the position and angle of the flip chip to improve the mounting accuracy of the flip chip, the welding repairing module is used for carrying out flip chip welding according to the welding accuracy parameters, judging whether the flip chip welding effect is quantized according to the quantized parameters after the flip chip welding, judging whether the temperature probe is used for carrying out the temperature feedback control of the temperature controller and the temperature controller is used for carrying out the temperature feedback control of the temperature controller according to the temperature controller in the temperature feedback welding process, and the temperature controller is used for heating the temperature controller to control the temperature feedback of the flip chip.

In this embodiment, the existing process of reflow soldering and heating tin melting in the flip chip soldering process is replaced by using the flip chip soldering device to perform laser heating soldering, so that when some small batches of production are performed, the soldering cost such as the opening, preheating and time of reflow soldering is obviously reduced, and meanwhile, the problem that a certain chip cannot be accurately repaired manually in a repair process of poor soldering due to undersize of the chip is solved. The flip chip welding Device can realize non-contact processing, directional heating and CCD (Charge-Coupled Device) positioning, is the best choice for local selective heating welding, can effectively avoid the influence on other peripheral products and devices in welding, and also monitors the welding process in real time by using a CCD camera to ensure the visualization of the welding process.

In addition, the chip welding database stores relevant data of the laser heating system for flip chip welding and repairing, including reference to solder paste thickness, solder paste thickness allowable deviation, reference to solder paste coverage rate, solder paste coverage rate allowable deviation, reference to solder paste volume, solder paste abnormal threshold value, solder paste standard volume range and the like, and the data in the chip welding database can be obtained by directly inquiring in a public database such as a laser society database or can also be obtained by cooperation with related departments such as packaging factories, flip chip manufacturers and the like.

Fig. 2 is a flowchart of a flip chip bonding apparatus according to an embodiment of the present application. The flip chip welding is realized based on a flip chip welding device, the flip chip welding device specifically comprises a laser heating head, a laser, a temperature measuring probe, a temperature controller and a CCD camera, wherein the CCD camera is used for monitoring the flip chip welding process in real time according to the requirements of upper computer process files such as PCB design files and the like, covering the laser, the laser heating head and the like and is responsible for positioning the positions of the flip chip and a bonding pad, the laser heating head is used for adjusting the spot size to control the heating area of the flip chip and the bonding pad in the heating process, the temperature measuring probe is used for detecting the temperature of the flip chip and the bonding pad to feed back to the temperature controller, the temperature controller is used for adjusting the output power of the laser in real time according to the temperature setting requirements of the upper computer process files, and the temperature controller, the temperature measuring probe and the laser are mutually used for carrying out real-time signal transmission and feedback. The temperature controller and the CCD camera are coaxial with the laser light path, and various combination modes can exist according to actual needs, as shown in a laser light path combination diagram of FIG. 3, in the diagram, 1 is a laser, 2 is a collimating lens, 3 is a micro lens array, 4 is a focusing lens, 5 is a flip chip and a bonding pad, 6 is a CCD camera, and 7 is a temperature measuring probe. The first laser path combination is suitable for scenes needing to realize a longer optical path in a limited space, such as a plurality of spectrum analysis instruments with specific requirements on the optical path, the second laser path combination is suitable for occasions needing to quickly and efficiently focus laser to a specific small area, such as fine processing in laser processing, and the conical structure can be used for focusing laser energy to a micro area on a workpiece, and the third laser path combination is suitable for scenes needing to guide the laser to a specific direction or position, such as laser communication, and guides the laser from a transmitting source to a specific receiving device.

The laser heating head comprises a collimating lens, a focusing lens group and a micro lens group, wherein the collimating lens is used for reducing the divergence angle of a circular light beam output by the optical fiber laser, the focusing lens group comprises a first focusing lens and a second focusing lens, the micro lens group comprises a first cylindrical micro lens array and a second cylindrical micro lens array, the first cylindrical micro lens array comprises a first cylindrical micro lens and a second cylindrical micro lens, the second cylindrical micro lens array comprises a third cylindrical micro lens and a fourth cylindrical micro lens, the distance between the first cylindrical micro lens array is used for controlling the length of an output light spot, the distance between the first cylindrical micro lens array and the first focusing lens is used for controlling the width of the output light spot, the distance between the second cylindrical micro lens array and the second focusing lens is used for controlling the second group micro lens array in the second direction, the first group micro lens array and the second group micro lens array are orthogonal, and the working faces of the two groups of micro lens arrays coincide to form an imaging micro lens array in the orthogonal direction. The laser heating head is a bidirectional uniform spot-changing system with adjustable length and width respectively, and is a reverse unidirectional uniform spot-changing system which is added on the basis of the unidirectional uniform spot-changing system, so that the uniform adjustment of light spots in the forward and reverse directions is realized.

Referring to fig. 4, a diagram of a unidirectional uniform spot-changing system according to an embodiment of the present application is shown, in which 8 is a collimator lens, 9 and 10 are two cylindrical microlenses, and 11 and 12 are two focusing lenses. In the figure, 9 and 10 form a group of cylindrical microlens arrays, in the application, cylindrical microlenses are of uniform specification, 11 and 12 form a focusing lens group, and the focusing lens group and the cylindrical microlens arrays form the microlens array in the direction. When the 9 or 10 micro lens array moves back and forth along the direction indicated by the arrow, the corresponding light spot width which can obtain uniform direction changes. The opposite direction is a simple collimation focusing system, so that the light spot distribution which is the same as that of the original light source is obtained, and the light spot width can be changed through defocusing. Fig. 5 and 6 are respectively a uniform spot diagram of the unidirectional uniform spot variation system and a spot variation diagram of the unidirectional uniform spot variation system after the interval of the micro lens group is changed.

Fig. 7 is a schematic diagram of a unidirectional uniform speckle-changing system according to an embodiment of the application. In the unidirectional uniform spot-changing system, light beams emitted by a light source pass through a collimating lens to form light beams with small divergence angles, a first micro-lens array divides the collimated light beams into a plurality of sub-light beams, a second micro-lens array is combined with a focusing lens to serve as a group of objective lenses, images of each light beam in the first array are overlapped on a uniform light plane to form uniform flat-top light beams, and the size of uniform light spots formed after focusing depends on the focal length of the sub-lenses in the array and the focal length of the focusing lens. Wherein the diameter of the individual beams on the second microlens array must be smaller than the sub-lens spacing to avoid lens aperture overfilling and light loss.

As shown in fig. 8, in the drawing, 13 is a collimating lens, 14 is a first cylindrical microlens, 15 is a second cylindrical microlens, 16 is a third cylindrical microlens, 17 is a fourth cylindrical microlens, 18 is a first focusing lens, 19 is a second focusing lens, 18 and 19 form a focusing lens group, 14 and 15 form a first cylindrical microlens array, a first group of microlens arrays in a first direction with the focusing lens group, 16 and 17 form a second cylindrical microlens array, a second group of microlens arrays in a second direction with the focusing lens group, the second group of microlens arrays are orthogonal to the first group of microlens arrays, and the two groups of microlens arrays form an imaging microlens array in an orthogonal direction. The light spots in the two directions of the laser heating head are uniformly distributed, the length and the width of the output rectangular light spot can be separately and independently adjusted, and the two directions form a micro-lens array homogenizing system.

The uniform light spot diagram of the laser heating head is shown in fig. 9, wherein the light spot size of the rectangular light spot heating head is in the range of 0.05-12mm, and the two groups of microlenses respectively form uniform light spots in corresponding directions, so that rectangular uniform light is formed. When the pitch of one group of microlenses is changed, the spot length in the corresponding direction is changed independently, and the spot change diagram of the laser heating head is shown in fig. 10.

The method comprises the steps of obtaining solder paste quality parameter reference data from a preset chip welding database, wherein the solder paste quality parameter reference data comprise reference solder paste thickness, solder paste thickness allowance deviation, reference solder paste coverage rate, solder paste coverage rate allowance deviation, reference solder paste volume allowance deviation, obtaining solder paste thickness actual deviation based on the reference solder paste thickness and the solder paste thickness allowance deviation and comparing the solder paste thickness actual deviation with the solder paste thickness allowance deviation to obtain solder paste thickness influence parameters, obtaining solder paste coverage rate actual deviation based on the reference solder paste coverage rate and the solder paste coverage rate allowance deviation and comparing the solder paste coverage rate actual deviation with the solder paste coverage rate allowance deviation to obtain solder paste coverage rate influence parameters, obtaining solder paste volume influence parameters based on the reference solder paste volume and the solder paste volume allowance deviation, respectively carrying out coupling treatment on the solder paste thickness influence parameters, the solder paste coverage rate influence parameters and the solder paste volume influence parameters by using solder paste quality parameter contribution degree data to obtain solder paste abnormal quantization indexes, and jointly representing solder paste quality contribution degree and solder paste contribution degree of solder paste quality, and solder paste contribution degree of solder paste quality comprises solder paste contribution degree and solder paste quality contribution degree.

The abnormal quantitative index of the solder paste is obtained by the following steps:

;

Where a represents a solder paste abnormality quantization index, γ ₁ represents a solder paste thickness contribution degree, γ ₂ represents a solder paste coverage contribution degree, and γ ₃ represents a solder paste volume contribution degree.

The thickness of the solder paste is represented by t, which is an average value of the solder paste thickness of each preset measuring point on the surface of the solder paste, and can be obtained by non-contact measurement of the height difference between each measuring point on the surface of the solder paste and a reference plane of a bonding pad by using equipment such as a laser displacement sensor, wherein t ₁ represents the reference solder paste thickness, and t ₂ represents the allowable deviation of the solder paste thickness.

C represents the solder paste coverage rate, a CCD camera can be used for acquiring a solder pad area, a binary segmentation algorithm is used for separating solder paste from a background area in a picture of the solder pad area, and the ratio of solder paste pixels to the pixels of the solder pad area is calculated, c ₁ represents the reference solder paste coverage rate, and c ₂ represents the solder paste coverage rate allowable deviation.

V represents the volume of solder paste, the contour of the height of solder paste can be scanned by using a volume measuring instrument such as a laser displacement sensor, and the contour is calculated based on the accumulation of the height of solder paste and the pixel area of solder paste, v ₁ represents the volume of reference solder paste, and v ₂ represents the allowable deviation of the volume of solder paste.

The chip welding database, gamma ₁、γ₂ and gamma ₃ are the contribution degrees corresponding to the thickness of the solder paste, the coverage rate of the solder paste and the area of the solder paste respectively, and the contribution degrees are the contribution degrees for quantitatively representing and measuring the influence indexes of the quality parameters of the solder paste on the lens film. Specifically, the solder paste thickness, solder paste coverage rate and solder paste volume are configured with independent mapping relation tables, which contain one-to-one or many-to-one correspondence relation, and each possible solder paste quality parameter value and corresponding contribution degree are recorded in the tables. In practical application, the solder paste thickness, the solder paste coverage rate and the solder paste mass measured in real time are respectively input into the corresponding mapping relation tables, so that the corresponding contribution degree can be automatically matched, wherein the value range of the contribution degree is between 0 and 1.

In this embodiment, the thickness of the solder paste, the coverage rate of the solder paste, and the volume of the solder paste are related to each other, for example, in the case of consistent thickness of the solder paste, the larger the coverage rate of the solder paste, the larger the volume of the solder paste, if the uneven height of the solder paste such as edge collapse occurs, the high coverage rate of the solder paste but the small volume of the solder paste may result, and if the isocentric protrusion of the print pull tip occurs, the normal coverage rate of the solder paste but the volume of the solder paste exceeds the standard. When the coverage rate of the solder paste is unchanged, the larger the thickness of the solder paste is, the larger the volume of the solder paste is, and the too thick thickness of the solder paste is easy to transversely spread during reflow, so that the coverage rate of the solder paste exceeds the standard, and the too thin thickness of the solder paste can cause insufficient coverage rate of the solder paste.

As shown in fig. 11, a graph of printing dynamic adjustment thinking is provided in an embodiment of the present application, wherein the quantization index is a solder paste abnormality quantization index, the threshold is a solder paste abnormality threshold, the maximum value is the maximum value of a solder paste standard volume range, the minimum value is the minimum value of the solder paste standard volume range, and the range is the solder paste standard volume range. Based on printing quality parameters obtained through real-time monitoring, a tin paste abnormal quantization index is obtained, judgment is carried out based on the tin paste abnormal quantization index and a tin paste abnormal threshold, if the tin paste abnormal quantization index is smaller than or equal to the tin paste abnormal threshold, flip chip lamination prompt is sent out, if the tin paste abnormal quantization index is larger than the tin paste abnormal threshold, judgment is carried out based on tin paste volume, when the tin paste volume is larger than the maximum value of a tin paste standard volume range, a tin paste excessive prompt is sent out, the scraper pressure is increased, when the tin paste volume is smaller than the minimum value of the tin paste standard volume range, a tin paste insufficient prompt is sent out, the scraper pressure is reduced, and when the tin paste volume is within the tin paste standard volume range, a demolding abnormal prompt is sent out, and the demolding speed is adjusted.

Specifically, the step of judging whether to perform printing dynamic adjustment based on the obtained solder paste abnormality evaluation result includes:

And comparing the abnormal tin paste quantization index with the abnormal tin paste threshold, if the abnormal tin paste quantization index is larger than the abnormal tin paste threshold and the tin paste volume is larger than the maximum value of the abnormal tin paste volume range, sending out excessive tin paste prompt, failing to directly attach the flip chip, matching the abnormal tin paste deviation index with the scraper pressure regulating value corresponding to each abnormal tin paste deviation index range preset in the chip welding database, and increasing the scraper pressure in the next tin paste printing process according to the matched scraper pressure regulating value, so that tin paste overflow and non-uniformity can be avoided, and tin paste waste is reduced. In the chip welding database, each abnormal deviation index range of the solder paste and the corresponding pressure regulating value of the scraper form a mapping relation table, each abnormal deviation index range of the solder paste and the corresponding pressure regulating value of the scraper are recorded in the table, the relations can be one-to-one or many-to-one, when the pressure regulating value of the scraper is obtained, the abnormal deviation index of the solder paste is only required to be input into the mapping relation table, the chip welding database can rapidly position and return the pressure regulating value of the scraper corresponding to the abnormal deviation index of the solder paste, and the demoulding speed regulating value is the same.

If the abnormal quantitative index of the solder paste is larger than the abnormal threshold value of the solder paste and the volume of the solder paste is in the standard volume range of the solder paste, the abnormal quantitative index of the solder paste is larger than the abnormal threshold value of the solder paste and the volume of the solder paste is smaller than the minimum value of the standard volume range of the solder paste, the abnormal quantitative index of the solder paste is not larger than the abnormal threshold value of the solder paste, the abnormal quantitative index of the solder paste cannot be directly used for flip chip bonding, the detachment condition of the solder paste on a steel mesh is directly influenced by the speed of the demolding, the quality and distribution of the solder paste on a bonding pad are influenced, if the demolding speed is slow, the contact time of the solder paste and the side wall of the steel mesh is long, the adhesion force can lead to the solder paste to be lifted by the steel mesh to form a pull tip, if the demolding speed is fast, the solder paste is not completely separated from the steel mesh openings, partial solder paste can be torn, the solder paste remains in the openings, the quantity of the solder paste on the bonding pad is insufficient, the abnormal quantitative index of the solder paste is compared with the corresponding solder paste in the preset data of the steel mesh, the abnormal quantitative index is adjusted to be uniform or the solder paste is distributed on the solder paste according to the preset data, and the dynamic value is adjusted to be slow, and the problem is solved, the problem is that the abnormal quantitative index is well is adjusted, and the solder paste is printed.

And if the abnormal quantitative index of the solder paste is smaller than or equal to the abnormal threshold of the solder paste, sending out a flip chip bonding prompt.

In this embodiment, when the abnormal quantization index of the solder paste is greater than the abnormal threshold of the solder paste, it is indicated that the solder paste printed on the solder pad does not reach the standard, if the solder paste is not oxidized, a preset person can be prompted to wipe the solder pad with absolute ethyl alcohol or a special cleaning agent to remove the residual solder paste, the unoxidized solder paste can be collected by a stainless steel shovel blade and put back into the original tank under the premise that the solder paste is not polluted, and solder paste printing is performed on the solder pad again, if the solder paste is oxidized, the solder paste cannot be returned to the tank for use, and the oxidized residual solder pad needs to be removed by using an ultrasonic cleaner. The invention dynamically adjusts the scraper pressure and the demoulding speed in the solder paste printing process based on the solder paste abnormal quantization index, and can ensure that the solder paste quantity and the solder paste quality are in an optimal range, thereby improving the subsequent flip chip welding quality and the production efficiency. The printing precision of the solder paste is directly affected by the scraper pressure and the demoulding speed, and the printing effect of the solder paste can be dynamically optimized by precisely controlling the scraper pressure and the demoulding speed in the solder paste printing process, so that the thickness distribution of the solder paste on a bonding pad is ensured to be uniform, excessive or insufficient solder paste accumulation is avoided, printing defects are reduced, the reliability of the subsequent flip chip welding is improved, the solder paste printing process is fine, and the welding quality and stability of the flip chip are obviously improved.

Further, after the flip chip is attached, judging whether to carry out dynamic attaching compensation according to attaching offset and rotation offset of the flip chip and a bonding pad comprises the steps of acquiring an attaching offset threshold and a rotation offset threshold from a preset chip welding database, and if the attaching offset exceeds the attaching offset threshold, driving the flip chip to move to bonding center point coordinates of the bonding pad by using a chip mounter, wherein the bonding center point coordinates of the bonding pad can be obtained by extracting bonding pad outlines in bonding pad images acquired by a CCD camera, and directly calculating the bonding pad outlines by using a geometric gravity center method. The chip mounter is responsible for laminating convex points of the flip chip with target coordinates, wherein the target coordinates default to pad center point coordinates set by a PCB (Printed Circuit Board ) design file, when laminating offset exceeds a laminating offset threshold, the pad center point coordinates are not pad laminating center point coordinates, the pad laminating center point coordinates need to be used as target coordinates of the chip mounter to move the chip again, accurate alignment of the flip chip can be ensured, and accordingly the accuracy of flip chip mounting is improved, if the laminating offset does not exceed the laminating offset threshold, whether the rotating offset exceeds the rotating offset threshold is judged, if so, flip chip welding cannot be directly carried out, a compensation angle is generated according to the laminating offset, the spindle angle of the flip chip is driven to the compensation angle by the chip mounter, correct angle positioning of the flip chip on the pad is ensured, otherwise, a flip chip welding prompt is sent out, the compensation angle is a reverse correction value of the rotating offset, the chip center point coordinates and the chip spindle angle can be obtained through the CCD camera positioning chip, the laminating offset is calculated according to the chip center point coordinates and the preset solder paste coordinates, and the absolute deviation is obtained according to the chip spindle angle and the preset pad spindle angle.

In the embodiment, the mounting accuracy and reliability are ensured by dynamically adjusting the mounting position and angle of the compensation chip, and poor welding caused by offset or angle error is reduced. The flip chip angle deviation can be accurately identified and processed by judging whether the rotation deviation exceeds the rotation deviation threshold, so that welding failure caused by the rotation deviation is effectively reduced. According to the invention, the mounting position and angle of the flip chip are dynamically adjusted and compensated, so that the flip chip bonding process is optimized, the bonding accuracy of the flip chip is remarkably improved, the possibility of misplacement of the patch is reduced, the risk of welding defects caused by misplacement of the patch is effectively reduced, and the stability and accuracy of final welding quality are ensured.

The method comprises the steps of obtaining welding precision parameter reference data from a preset chip welding database after flip chip welding according to welding precision parameters, wherein the welding precision parameter reference data comprises critical welding spot position deviation, reference welding ball size, welding ball size allowable deviation and critical attaching deviation, performing duty ratio approach calculation on the critical welding spot position deviation and the critical attaching deviation respectively with the welding spot position deviation and the attaching deviation to obtain welding spot position deviation influence parameters and attaching deviation influence parameters, obtaining welding ball size actual deviation based on the welding ball size allowable deviation and the welding ball size, comparing the welding ball size actual deviation with the reference welding ball size to obtain welding ball size influence parameters, performing weighting calculation on the welding spot position deviation influence parameters, the welding ball size influence parameters and the attaching deviation influence parameters respectively by utilizing welding precision parameter contribution data, and performing coupling treatment on a weighting calculation result to obtain a welding effect quantization index, wherein the welding effect quantization index represents influence degree quantization data of the welding precision parameters, the welding precision parameters comprise welding spot position deviation, welding ball size and attaching deviation contribution degree, and attaching deviation contribution degree.

The welding effect quantization index is obtained as follows:

;

Where w represents a soldering effect quantization index, γ ₄ represents a solder joint positional deviation contribution degree, γ ₅ represents a solder ball size contribution degree, and γ ₆ represents a bonding offset contribution degree.

D represents the position deviation of the welding spot, which is the offset of the actual position of the welding spot and the design position of the PCB design file, the actual welding spot image can be aligned with the design template, the offset of the central point is calculated, and d ₁ represents the position deviation of the critical welding spot.

S represents the solder ball size, and the solder ball is placed on the contact point of the flip chip and the bonding pad, and can be calculated by measuring the projection diameter of the solder ball in the picture obtained by the CCD camera, s ₁ represents the reference solder ball size, and s ₂ represents the allowable deviation of the solder ball size.

B denotes a bonding offset, and b ₁ denotes a critical bonding offset.

In the chip welding database, gamma ₄、γ₅ and gamma ₆ are contribution degrees corresponding to the position deviation of a welding spot, the size of a welding ball and the fitting offset, and the contribution degrees are the contribution degrees for quantitatively representing and measuring the welding precision parameters and the welding effect quantization indexes. Specifically, the position deviation of the welding spot, the size of the welding ball and the attaching offset are configured with independent mapping relation tables, which contain one-to-one or many-to-one correspondence relation, and each possible welding precision parameter value and the corresponding contribution degree are recorded in the tables. In practical application, the welding spot position deviation, the welding ball size and the attaching deviation measured in real time are respectively input into the corresponding mapping relation tables, so that the corresponding contribution degree can be automatically matched, wherein the value range of the contribution degree is between 0 and 1.

In this embodiment, the position deviation of the solder joint, the size of the solder ball and the bonding offset are related to each other, for example, the larger the bonding offset of the chip is, the farther the center of the solder ball is away from the pad, resulting in synchronous increase of the position deviation of the solder joint, when the bonding offset exceeds the radius of the pad, the solder ball may be completely misplaced, causing open circuit, the smaller the size of the solder ball may result in insufficient strength of the solder ball, and the solder joint position deviation is aggravated due to the fact that the surface tension is unable to self-align during reflow soldering, and the too large bonding offset may result in uneven extrusion of solder paste by the chip, loss of part of solder paste of the solder joint, and accumulation on the other side, resulting in abnormal size distribution of the solder ball.

Further, the step of judging whether flip chip repair is performed by using the temperature probe, the temperature controller and the laser based on the quantitative evaluation result comprises the steps of obtaining a welding effect threshold value from a preset chip welding database, comparing the welding effect quantitative index with the welding effect threshold value, sending a welding effect standard prompt without additional processing if the welding effect quantitative index is larger than or equal to the welding effect threshold value, sending a welding effect non-standard prompt if the welding effect quantitative index is smaller than the welding effect threshold value, marking the difference value between the welding effect threshold value and the welding effect quantitative index as a welding effect deviation value, matching the welding effect deviation value with chip adjustment proportion corresponding to each preset welding effect deviation range in the chip welding database, forming a mapping relation table in which each welding effect deviation range corresponds to the chip adjustment proportion, wherein the chip adjustment proportion corresponding to each welding effect deviation range is recorded, the relation can be one-to-one or more-to-one, and when the chip adjustment proportion is obtained, the chip database can rapidly position and return to the flip chip repair device according to the chip adjustment proportion corresponding to the welding effect prompt.

The flip chip repairing comprises abnormal chip removing and replacement flip chip welding, wherein in the abnormal chip removing process, the position of the abnormal chip is firstly positioned through a CCD camera, the abnormal chip removing process is monitored, the size of the abnormal chip is adjusted through combining a chip adjusting proportion, then the center of a light spot is aligned with an abnormal welding spot through a laser heating head, the abnormal chip is adjusted to a target chip size, meanwhile, the temperature of the flip chip and a welding disc is detected through a temperature measuring probe and fed back to a temperature controller, the output power of a laser is controlled in real time through the temperature controller to remove the abnormal chip, the replacement flip chip welding means that the replacement flip chip is welded through a flip chip welding device, the replacement flip chip is a brand-new flip chip which meets quality standards, and can be accurately welded on the welding disc on a substrate at the original welding position.

In this embodiment, in the flip chip picture obtained after welding by the CCD camera, the edge of the chip outline is extracted by using an edge detection algorithm such as Canny edge detection, and the outline extraction algorithm is used to extract the outline of the closed area, i.e. the outline of the abnormal chip, in the image, to obtain a set of closed boundaries, which represent the external outline of the abnormal chip, and based on the extracted outline pixels and the actual sizes corresponding to the pixels, the abnormal chip size can be obtained, and the product of the chip size adjustment ratio and the abnormal chip size can be obtained to obtain the target chip size. According to the invention, whether the welding effect of the flip chip reaches the standard can be accurately judged by comparing the quantitative index of the welding effect with the threshold value of the welding effect, and the flip chip repair is automatically carried out based on the chip adjustment proportion obtained by the deviation value of the welding effect, so that the accuracy of welding quality control is improved, manual intervention can be effectively reduced, the flip chip repair process is automatically guided, the defect rate of welding spots is reduced, the cost of the welding and repair processes of the flip chip is reduced, and the improvement of the welding and repair quality of the flip chip is realized.

As an embodiment of the second aspect, as shown in fig. 12, a flowchart of a laser heating method for flip chip bonding and repair is provided in an embodiment of the present application. The application provides a laser heating method for flip chip welding and repairing, which comprises the specific steps of carrying out abnormal solder paste assessment on a solder pad after solder paste printing according to solder paste quality parameters, judging whether to carry out printing dynamic adjustment based on obtained abnormal solder paste assessment results, wherein the printing dynamic adjustment is used for dynamically setting the pressure and demolding speed of a scraper in the next solder paste printing process so as to improve the uniformity of solder paste thickness distribution, judging whether to carry out dynamic lamination compensation according to the lamination offset and rotation offset of a flip chip and the solder pad after the flip chip is laminated, wherein the dynamic lamination compensation is used for carrying out dynamic adjustment on the position and angle of the flip chip so as to improve the lamination accuracy of the flip chip, carrying out flip chip welding by utilizing a temperature probe, a temperature controller and a laser, carrying out quantitative assessment on the welding effect of the flip chip according to welding accuracy parameters after the flip chip welding, judging whether to carry out flip chip repairing by utilizing the temperature probe, the temperature controller and the laser based on quantitative assessment results, wherein the temperature probe is used for detecting the temperature of the flip chip and the solder pad so as to feed back to the temperature controller, and the temperature controller is used for controlling the heating temperature of the solder pad in the flip chip welding process by adjusting output power of the temperature feedback in real time according to temperature setting requirements.

In summary, according to the embodiment, through dynamic evaluation and adjustment of solder paste quality parameters, flip chip attaching precision and welding precision parameters, the accuracy of flip chip welding and repairing quality is ensured, firstly, abnormal evaluation of solder paste is carried out according to the solder paste quality parameters, whether dynamic adjustment is needed in a printing process is judged, the scraper pressure and demolding speed are optimized so as to improve uniformity of solder paste thickness distribution, then, in the flip chip attaching process, whether dynamic attaching compensation is carried out is judged according to attaching offset and rotating offset of a chip and a bonding pad, accurate butt joint of the chip position and angle is ensured, attaching precision is improved, finally, after welding is completed by using a flip chip welding device, welding effect evaluation is carried out according to the welding precision parameters, whether flip chip repairing is needed is judged, welding effect is further optimized, high-efficiency and high-precision control of temperature and heat distribution in the whole flip chip welding and repairing process is realized based on a laser heating method, and the improvement of flip chip welding and repairing quality is realized.

It will be apparent to those skilled in the art that embodiments of the present invention may be provided as a method, system and method, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of systems and methods, apparatus (systems and methods), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. The laser heating system for flip chip welding and repairing is characterized by comprising a solder paste adjusting module, a chip welding module, a welding repairing module and a chip welding database;

The solder paste adjusting module is used for carrying out solder paste abnormality evaluation on a solder paste printed solder pad according to solder paste quality parameters, judging whether to carry out printing dynamic adjustment or not based on an obtained solder paste abnormality evaluation result, wherein the printing dynamic adjustment is used for dynamically setting the pressure of a scraper and the demolding speed in the next solder paste printing process so as to improve the uniformity of solder paste thickness distribution;

The chip welding module is used for judging whether to carry out dynamic lamination compensation according to the lamination offset and the rotation offset of the flip chip and the bonding pad after the flip chip is laminated, and the dynamic lamination compensation is used for dynamically adjusting the position and the angle of the flip chip so as to improve the lamination precision of the flip chip;

The welding repair module performs flip chip welding by using a temperature probe, a temperature controller and a laser, performs quantitative evaluation on the welding effect of the flip chip according to welding precision parameters after the flip chip welding, judges whether to perform flip chip repair by using the temperature probe, the temperature controller and the laser based on the quantitative evaluation result, wherein the temperature probe is used for detecting the temperature of the flip chip and a bonding pad so as to feed back the temperature to the temperature controller, and the temperature controller is used for adjusting the output power of the laser in real time through temperature feedback so as to control the heating temperature of the bonding pad in the welding process of the flip chip according to temperature setting requirements.

2. The laser heating system for flip chip bonding and repair of a semiconductor device of claim 1, wherein the step of performing solder paste anomaly evaluation on solder paste printed pads based on solder paste quality parameters comprises:

obtaining solder paste quality parameter reference data from a preset chip welding database, wherein the solder paste quality parameter reference data comprises reference solder paste thickness, solder paste thickness allowable deviation, reference solder paste coverage rate, solder paste coverage rate allowable deviation, reference solder paste volume and solder paste volume allowable deviation;

Obtaining the actual deviation of the thickness of the solder paste based on the reference thickness of the solder paste and the thickness of the solder paste, and comparing the actual deviation with the allowable deviation of the thickness of the solder paste to obtain the influence parameters of the thickness of the solder paste;

obtaining the actual deviation of the solder paste coverage based on the reference solder paste coverage and the solder paste coverage, and comparing the actual deviation with the allowable deviation of the solder paste coverage to obtain the influence parameters of the solder paste coverage;

obtaining actual deviation of the tin paste volume based on the reference tin paste volume and the tin paste volume, and comparing the actual deviation with the permissible deviation of the tin paste volume to obtain a tin paste volume influence parameter;

Weighting coupling processing is respectively carried out on the solder paste thickness influence parameter, the solder paste coverage rate influence parameter and the solder paste volume influence parameter by utilizing the solder paste quality parameter contribution degree data, so as to obtain a solder paste abnormal quantization index;

the abnormal tin paste quantization index represents quantitative data of the influence degree of tin paste quality parameters on the tin paste state on the bonding pad, wherein the tin paste quality parameters comprise tin paste thickness, tin paste coverage rate and tin paste volume;

the solder paste quality parameter contribution data includes a solder paste thickness contribution, a solder paste coverage contribution, and a solder paste volume contribution.

3. The laser heating system for flip chip bonding and repair of a semiconductor device of claim 2, wherein the step of determining whether to perform printing dynamics adjustment based on the obtained solder paste anomaly evaluation result comprises:

acquiring a solder paste abnormal threshold value and a solder paste standard volume range from a preset chip welding database;

If the abnormal tin paste quantization index is larger than the abnormal tin paste threshold and the tin paste volume is larger than the maximum value of the standard tin paste volume range, a tin paste excessive prompt is sent out, the abnormal tin paste deviation index is matched with the scraper pressure regulating values corresponding to the abnormal tin paste deviation index ranges preset in the chip welding database, the scraper pressure in the next tin paste printing process is increased according to the matched scraper pressure regulating values, and the abnormal tin paste deviation index represents the difference between the abnormal tin paste quantization index and the abnormal tin paste threshold;

If the abnormal quantitative index of the solder paste is larger than the abnormal threshold of the solder paste and the volume of the solder paste is smaller than the minimum value of the standard volume range of the solder paste, a solder paste shortage prompt is sent out, and the pressure of the scraper in the next solder paste printing process is reduced according to the pressure regulating value of the scraper;

If the abnormal tin paste quantization index is larger than the abnormal tin paste threshold and the tin paste volume is within the standard tin paste volume range, sending out abnormal tin paste demoulding prompt, matching the abnormal tin paste quantization index with a demoulding speed adjusting value corresponding to each abnormal tin paste quantization index preset in a chip welding database, and dynamically adjusting the demoulding speed in the next tin paste printing process according to the matched demoulding speed adjusting value;

4. The laser heating system for flip chip bonding and repairing as set forth in claim 1, wherein the step of determining whether to perform dynamic bond compensation based on the bond offset and the rotational offset of the flip chip and the bonding pad after the flip chip bonding comprises:

acquiring a laminating offset threshold and a rotation offset threshold from a preset chip welding database;

If the bonding offset exceeds the bonding offset threshold, driving the flip chip to move to the bonding center point coordinate of the bonding pad by using a chip mounter;

if the bonding offset does not exceed the bonding offset threshold, judging whether the rotation offset exceeds the rotation offset threshold, if so, generating a compensation angle according to the bonding offset, driving the main shaft angle of the flip chip to the compensation angle by using a chip mounter, and otherwise, sending out a flip chip welding prompt.

5. The laser heating system for flip chip bonding and repairing of claim 1, wherein the flip chip bonding is realized based on a flip chip bonding device, and the flip chip bonding device specifically comprises a laser heating head, a laser, a temperature measuring probe, a temperature controller and a CCD camera;

The CCD camera is used for positioning the chip position and monitoring the flip chip welding process in real time;

the laser heating head is used for adjusting the spot size so as to control a heating area in the pad heating process;

The temperature controller, the temperature measuring probe and the laser mutually perform real-time signal transmission and feedback.

6. A laser heating system for flip chip bonding and repair according to claim 5 wherein the laser heating head comprises a collimator lens, a focusing lens group and a micro lens group;

The collimating mirror is used for reducing the divergence angle of the circular light beam output by the fiber laser;

the focusing lens group comprises a first focusing lens and a second focusing lens;

the micro-lens group comprises a first cylindrical micro-lens array and a second cylindrical micro-lens array, the first cylindrical micro-lens array comprises a first cylindrical micro-lens and a second cylindrical micro-lens, and the second cylindrical micro-lens array comprises a third cylindrical micro-lens and a fourth cylindrical micro-lens;

the distance between the first cylindrical micro lens arrays is used for controlling the length of an output light spot;

the first cylindrical micro lens array and the first focusing lens form a first group of micro lens arrays with the first direction;

The spacing of the second cylindrical microlens array is used for controlling the width of the output light spots;

The second cylindrical microlens array and the second focusing lens form a second group of microlens arrays with the second direction;

The first group of microlens arrays are orthogonal to the second group of microlens arrays in direction, and the working faces of the two groups of microlens arrays are coincident to form an imaging microlens array in the orthogonal direction.

7. The laser heating system for flip chip bonding and repairing as claimed in claim 1, wherein the step of quantitatively evaluating the flip chip bonding effect based on the bonding accuracy parameter after the flip chip bonding comprises:

Acquiring welding precision parameter reference data from a preset chip welding database, wherein the welding precision parameter reference data comprises critical welding spot position deviation, reference welding ball size, welding ball size allowable deviation and critical laminating deviation;

performing duty ratio approach calculation on the critical welding spot position deviation and the critical laminating offset and the welding spot position deviation and the laminating offset respectively to obtain a welding spot position deviation influence parameter and a laminating offset influence parameter;

Obtaining the actual deviation of the solder ball size based on the allowable deviation of the solder ball size and the solder ball size, and comparing the actual deviation of the solder ball size with the reference solder ball size to obtain a solder ball size influence parameter;

Respectively carrying out weighting operation on the welding spot position deviation influence parameter, the welding ball size influence parameter and the attaching offset influence parameter by utilizing the welding precision parameter contribution degree data, and then carrying out coupling treatment on a weighting operation result to obtain a welding effect quantization index;

The welding effect quantization index represents the quantization data of the influence degree of welding accuracy parameters on the welding effect, wherein the welding accuracy parameters comprise welding spot position deviation, welding ball size and fitting deviation;

The welding precision parameter contribution data comprises welding spot position deviation contribution degree, welding ball size contribution degree and fitting offset contribution degree.

8. The laser heating system for flip chip bonding and repairing of claim 7, wherein the step of determining whether to perform flip chip repairing using the temperature probe, the temperature controller and the laser based on the quantitative evaluation result comprises:

Acquiring a welding effect threshold value from a preset chip welding database;

if the welding effect quantization index is greater than or equal to the welding effect threshold, sending a welding effect standard prompt without additional treatment;

If the welding effect quantization index is smaller than the welding effect threshold, a prompt that the welding effect does not reach the standard is sent, the difference value between the welding effect threshold and the welding effect quantization index is recorded as a welding effect deviation value, the welding effect deviation value is matched with chip adjustment proportions corresponding to the preset welding effect deviation ranges in the chip welding database, and the flip chip welding device is prompted to repair the flip chip according to the matched chip adjustment proportions.

9. A laser heating system for flip chip bonding and repair as defined in claim 8 wherein the flip chip repair includes abnormal chip removal and replacement flip chip bonding;

The abnormal chip is removed, namely, firstly, the position of the abnormal chip is positioned through a CCD camera, the abnormal chip removing process is monitored, the abnormal chip size is adjusted by combining the chip adjusting proportion, then the center of a light spot is aligned with an abnormal welding spot through a laser heating head, the abnormal chip size is adjusted to be the target chip size, meanwhile, the temperature of the flip chip and a bonding pad is detected through a temperature measuring probe and is fed back to a temperature controller, and the output power of a laser is controlled in real time through the temperature controller so as to remove the abnormal chip;

The replacement flip chip bonding means bonding the replacement flip chip with a flip chip bonding device.

10. A laser heating method for flip chip bonding and repairing, applied to the laser heating system for flip chip bonding and repairing according to any one of claims 1 to 9, comprising the steps of:

Carrying out abnormal solder paste assessment on a solder pad after solder paste printing according to solder paste quality parameters, judging whether to carry out printing dynamic adjustment or not based on the obtained abnormal solder paste assessment result, wherein the printing dynamic adjustment is used for dynamically setting the pressure of a scraper and the demoulding speed in the next solder paste printing process so as to improve the uniformity of solder paste thickness distribution;

Judging whether to carry out dynamic lamination compensation according to the lamination offset and the rotation offset of the flip chip and the bonding pad after lamination of the flip chip, wherein the dynamic lamination compensation is used for dynamically adjusting the position and the angle of the flip chip so as to improve the lamination precision of the flip chip;

And carrying out flip chip welding by using a temperature probe, a temperature controller and a laser, carrying out quantitative evaluation on the flip chip welding effect according to welding precision parameters after the flip chip welding, judging whether to carry out flip chip repair by using the temperature probe, the temperature controller and the laser based on quantitative evaluation results, wherein the temperature probe is used for detecting the temperature of the flip chip and a bonding pad to feed back the temperature to the temperature controller, and the temperature controller is used for adjusting the output power of the laser in real time through temperature feedback according to temperature setting requirements so as to control the heating temperature of the bonding pad in the flip chip welding process.