TWI578865B - A circuit board manufacturing method that can embed high pin count components - Google Patents

Description

Circuit board manufacturing method capable of embedding high pin number component

The invention relates to a method for manufacturing a buried component type circuit board and a buried component type circuit board structure, in particular to a circuit board manufacturing method suitable for embedding a high pin number component and a circuit board structure capable of embedding a high pin number component.

"Embedded Passives" refers to a process in which a passive component is embedded in a multilayer board, such as by etching or printing, and passive components such as capacitors or resistors are directly fabricated in the multilayer board. After the laminate is pressed into a multi-layered board, it replaces the discrete passive components welded on the surface of the board to increase the area of the board surface and the space on the board surface, and the main and passive components are arranged and routed. .

Now embedded in component boards, in addition to embedding passive components, similar technologies can also be used to embed electronic components such as active components to increase the overall package density. However, functions such as mobile phones and various electronic devices are becoming more and more powerful. Therefore, the number of I/Os in the chip continues to increase, the carrier process requires a higher number of pins, and the pitch needs to be finer. Since the number of I/Os of the chip is transmitted through the microcord structure of the circuit and the circuit board. The metal lines constitute an electrical connection, so how to greatly reduce the size of the micro-vias and the spacing between the micro-vias, and the size of the metal lines and the spacing between the metal lines, whether or not the number of high-pins can be buried in the board A major issue.

At present, the processing of micro-vias (Micorvia) is mainly laser-forming, and the laser drilling process includes conformal mask Drill, Enlarge Window Drill and direct copper processing ( Copper Direct Drill) and other methods. Referring to the first figure, the first figure is a schematic diagram of the open copper window method of the prior art. As shown in the first figure, the first layer 1a is sequentially formed with an insulating layer 3a, a second line 11a and a first line 7a. The copper window method is processed by providing an opening (copper window 9a) by etching in a portion of the second line 11a, and a laser 16a at the opening. Processing is performed to form via holes 14a on the insulating layer.

However, the aperture of the via hole formed by the copper window processing is limited by the beam diameter of the reticle, and especially by the limitation of the photoresist development and etching process, the aperture of the via hole cannot be changed. Smaller, so the circuit board's line density can not be more dense, and can not be connected to the active components of the high pin count.

Specifically, since the copper foil layer (second line 11a) is more difficult to absorb the wavelength of the laser, it is necessary to form an opening in the second line 11a by means of photoresist development and etching, but in terms of current process capability The minimum size of the window portion (corresponding to the photoresist layer) formed by the patterned photoresist layer is already above 50 μm , so the aperture of the opening formed by etching the second line 11a must be above 50 μm . .

In addition, after laser drilling, it is necessary to go through the Desmear process, which seriously causes the opening aperture to expand. The distance between the finished products can only reach 140 microns.

In addition, the prior art often uses mechanical drilling as a marking, the through hole diameter of the hole drilled into the hole is about 0.5~3mm, and the alignment tolerance and the IT transfer tolerance are about 15 μm , so the mechanical drilling is in the hitting place. The error generated is at least 30 μm or more, and the line width and line spacing of the metal line (copper pad) cannot be thinner and denser due to the limitation of the etching of the line itself.

It can be seen that the disadvantage of the prior art is that since the aperture of the opening formed by the processing of the copper window is limited to 50 μm or more, the span of the metal line is greater than 150 μm, and the interval between the metal lines is greater than 30 μm, resulting in It can only be connected to a wafer with a small number of pins, taking into account the above-mentioned alignment tolerance and IT transfer tolerance factors, resulting in the size of the micro-via, the spacing between the micro-vias and the size of the metal lines can not be smaller Therefore, the conventional techniques and structures are not suitable for embedding active components with high pin counts, so it is necessary to provide a circuit board manufacturing method that can embed high-density pin components.

The main object of the present invention is to provide a circuit board manufacturing method capable of embedding a high-pin number component, wherein a carrier board is coated with a metal layer; one side of the metal layer forms a first line, and the first line Included in the plurality of copper pads; covering a photoresist layer on the metal layer and the first line; patterning the photoresist layer such that the first line is only covered by the patterned photoresist layer; etching is not affected Patterning the metal layer covered by the photoresist layer and removing the photoresist layer; Forming an adhesive layer on a portion of the copper pad of the copper pad, and then fixing an element to the adhesive layer, the element having a plurality of I/O pins, wherein the copper pads of the corresponding components There is a micro copper window between the two copper pads, and each micro copper window corresponds to each I/O pin, and a copper window is not provided between the copper pads corresponding to the component, one of which is The copper window is set as a target; an insulating layer and a second metal layer are sequentially formed on the first line and the component, and the carrier is removed and the metal layer is etched until the adhesive layer corresponds to a portion of the micro copper window and a portion of the insulating layer corresponding to the copper window are exposed; optically aligning the target, and a drilling method is used to penetrate the I/O pin and the micro copper window The adhesive layer is formed to form a micro via hole on the I/O pin, and a portion of the insulating layer and the second metal layer corresponding to the copper window to form a through hole; The via hole and the via hole are plated with a conductive layer; the portion of the metal layer is removed by etching until the first line is exposed to form a plurality of microvias A plurality of through holes.

The inner ends of the microvias are electrically connected to the I/O pins, and the outer ends of the microvias are used by external circuits. In addition, the second metal layer is further patterned into a second line, and electrically connected to the first line through the through holes.

A main feature of the present invention is that a patterned dry film plating method is used to form a first line and a micro copper window and define a target point, and after removing the carrier board, the first line and the micro copper window form a buried line. Thereby, the adhesive layer is exposed and just in the micro copper window between any two copper pads, and the wavelength of the laser beam is hard to be absorbed by the copper, so that the laser beam is irradiated on the two copper pads and adhered. When the layer is layered, only the adhesive layer is penetrated to form a microvia, and thus the aperture of the microvia is the same as the micro copper window in the first line, and is not limited by the beam path of the mask.

In addition, the first line of the present invention is a buried line, so that the micro-via holes of the adhesion layer that will form the micro-vias are not covered by the metal layer, so the laser can directly penetrate the adhesion layer to form micro-vias; However, the entire surface of the insulating layer of the prior art is covered by a metal layer. Since it is difficult for the laser to penetrate the metal layer, it is necessary to first open the copper window in the metal layer through image transfer, and then use the laser to drill the insulating layer. However, after laser drilling, the hole diameter expansion problem will still be caused by the Desmear process, and the finished product pitch can only reach 140 μm .

Wherein, the first line and the micro copper window system are formed by patterning dry film plating on the metal layer, and the first line is formed by using the patterned electroplating dry film, and the line width of the first line is in terms of the existing process capability and The spacing can be easily controlled below 50 μm . In addition, in the process of fabricating the first line and the copper window, only the metal layer and the carrier plate of the same metal material are processed, and the process parameters are easy to control and easy to process, so the line width of the first line and the spacing of the first line are Can be precisely controlled.

Since the micro copper window in the first line formed by the patterned electroplating dry film can be easily controlled below 50 μm , the diameter of the formed micro via hole can be greatly reduced to 50 μm after laser drilling. In the following, the micro-via hole diameter is greatly reduced, so that the arrangement density of the micro-via holes can be greatly increased, thereby effectively meeting the requirements of embedding components with high-density pins, and the present invention uses a laser to open micro-vias and uses The target layer on the same layer as the micro-via hole is used to fix the component and perform laser drilling by means of optical alignment, thereby effectively improving the precision of the workpiece, and the circuit for embedding the high-density pin component is provided by the present invention. The manufacturing method and structure of the board, the diameter of the micro-via hole and the diameter of the copper pad can be reduced to less than 10 μm , and the number of pins of the embedded component is up to 20,000.

Another object of the present invention is to provide a circuit board structure capable of embedding a high pin number component, comprising at least an insulating layer, a first line and a second line, wherein the first line is buried in the insulating layer The second line is formed outside the insulating layer. The insulating layer is further embedded with an adhesive layer and an element. The element is fixed on the adhesive layer, wherein the adhesive layer has a plurality of components in the adhesive layer. The I/O pin 1 constitutes a plurality of microvias electrically connected, and the insulating layer has a plurality of vias that electrically connect the first line and the second line.

[study]

1a‧‧‧ first floor

3a‧‧‧Second floor

7a‧‧‧First line

9a‧‧‧ copper window pattern

11a‧‧‧second line

14a‧‧‧through hole

16a‧‧‧Laser

〔this invention〕

S10~S28‧‧‧Steps

10‧‧‧ Carrier Board

12‧‧‧metal layer

14‧‧‧First line

141‧‧‧ copper pad

16‧‧‧ photoresist layer

20‧‧‧Adhesive layer

100‧‧‧ components

101‧‧‧I/O pins

143‧‧‧micro copper window

145‧‧‧ copper window

21‧‧‧Insulation

22‧‧‧Second metal layer

201‧‧‧Microvia

211‧‧‧through hole

221‧‧‧second line

30‧‧‧ conduction layer

301‧‧‧Micro-vias

303‧‧‧through hole

A‧‧‧ Target

The first figure is a schematic diagram of the open copper window method of the prior art.

The second figure is an operational flowchart of a method for fabricating a circuit board capable of embedding a high pin number component.

The third to third J diagrams are schematic diagrams of a method of fabricating a circuit board capable of embedding a high pin number component.

The fourth figure is a schematic view of a preferred embodiment of a circuit board in which the high pin number component can be embedded in the present invention.

The embodiments of the present invention are described in more detail below with reference to the drawings and the component symbols. Explain that the person skilled in the art can implement it after studying this manual.

Referring to the second figure, an operation flowchart of a method for manufacturing a circuit board capable of embedding a high-pin number component according to the present invention, referring to FIGS. 3A to 3J, a circuit board manufacturing method capable of embedding a high-pin number component of the present invention Schematic diagram. As shown in the second figure, the method for fabricating the microvia of the circuit board of the present invention comprises the following steps S10, S12, S14, S16, S18, S20, S22, S24, S26 and S28. First, in conjunction with the third A picture, mainly from step S10, a metal layer 12 is plated on a carrier 10, wherein the metal layer 12 may be a single metal layer or a plurality of metal layers, and the metal layer is a copper layer. (Cu) or other suitable material metal layer, the carrier 10 may also be made of metal.

Next, in step S12, one side of the metal layer 12 is patterned to form a first line 14, which includes a plurality of copper pads 141, as shown in FIG. The first line 14 is formed by patterning dry film plating or other suitable means.

Thereafter, step S14 is performed to cover a photoresist layer 16 on the metal layer 12 and the first line 14, as shown in FIG. 3C.

In step S16, the photoresist layer 16 is patterned such that the first line 14 is only covered by the patterned photoresist layer 16, as shown in FIG. 3D. The photoresist layer 16 can be a dry film photoresist or a wet film photoresist.

Next, in step S18, the metal layer 12 not covered by the photoresist layer 16 is etched to a predetermined depth. For example, refer to the embodiment of the third E diagram, and in the third E diagram, the corresponding layer of the metal layer 12 is pre-processed. The regions of the component are all etched away, and the region not corresponding to the predetermined component is etched only by a portion of the metal layer. After the metal layer 12 is to be etched, the photoresist layer 16 is removed, as shown in FIG.

However, the etching manner of the metal layer 12 in the step S18 is determined according to the actual situation. The above etching method is merely an example for illustration, and is not intended to limit the scope of the present invention, that is, the correspondence of the metal layer 12. The area of the predetermined component can also be removed only by a portion, and the unremoved portion can be removed by a subsequent etching step.

Then, in step S20, an adhesive layer 20 is formed on a portion of the copper pads of the copper pads 141. For example, the adhesive layer 20 is disposed on a predetermined component region of the copper pads 141, and then an element 100 is fixed. On the adhesive layer 20, the component 100 has a plurality of I/O pins 101, There is a micro copper window 143 between any two copper pads 141 of the copper pads 141 corresponding to the component 100, and each micro copper window 143 corresponds to each I/O pin 101 and does not correspond to the component. Each of the copper pads 141 of 100 has a copper window 145, and one of the copper windows 145 is set as a target point A, as shown in the third F. Wherein, the arrangement of the component 100 can be aligned by using the target A to minimize the alignment tolerance.

Wherein, the component may be an active component, a passive component or other suitable component; wherein the adhesive layer 20 is formed by a dispensing technique, a screen print or a whole sheet.

Next, in step S22, an insulating layer 21 and a second metal layer 22 are sequentially formed on the first line 14 and the device 100. The insulating layer 21 covers the first line 14 and the component 100, and the carrier is removed. The plate 10 and the metal layer 12 are etched until the portion of the adhesive layer 20 corresponding to the micro copper window 143 and the portion of the insulating layer 21 corresponding to the copper window 145 are exposed, as shown in the third G diagram. Show.

Next, in step S24, the target point A is optically aligned, and the adhesion layer 20 is interposed between the I/O pin 101 and the micro copper window 143 by a drilling method to form a micro via hole. 201 is formed on the I/O pin 101, and a portion of the insulating layer 21 and the second metal layer 22 corresponding to the copper window 145 to form a through hole 211, as shown in FIG.

The drilling method is a laser drilling hole, and the aperture of the micro through hole 201 is determined by the size of the micro copper window 143.

Next, in step S26, a conductive layer 30 is plated in the micro via 201 and the via 211, as shown in FIG. The conductive layer 30 is a metal layer.

Then, in step S28, a portion of the metal layer 12 is removed by etching until the first line 14 is exposed to form a plurality of micro vias 301 and a plurality of vias 303, and the inner ends of the micro vias 301 are The I/O pins 101 constitute an electrical connection, and the outer ends of the microvias 303 are used by an external circuit. In addition, the second metal layer 22 is further patterned into a second line 221, and the first line 14 is electrically connected by the through holes 303, as shown in FIG.

According to the above process, a circuit board manufacturing method capable of embedding a high pin number component is manufactured. Referring to FIG. 3J, the circuit board structure in which the high pin number component can be embedded in the present invention includes at least one In the insulating layer 21, the first line 14 is buried in the insulating layer 21, and the second line 221 is formed outside the insulating layer 221, and the insulating layer 21 is further embedded with an adhesive layer 20 and an element 100. The component 100 is fixed on the adhesive layer 20, wherein the adhesive layer 20 has a plurality of microvias 301 electrically connected to the plurality of I/O pins 101 of the component 100, and the insulating layer 21 has The first line 14 and the second line 221 are configured to form a plurality of through holes 303 electrically connected.

Referring to the fourth figure, a schematic diagram of a preferred embodiment of a circuit board in which the present invention can be embedded in a high pin number component is shown. As shown in the fourth figure, the adhesive layer 20 is integrally attached to the first line 14, so that it is more convenient to process, that is, in the above step S20, the adhesive layer 20 is directly formed by a sheet or a roll. Attached to the first line 14, the portion of the adhesive layer 20 corresponding to the copper window 145 is also penetrated to form the through hole 211, the subsequent operation refers to the foregoing steps, and finally forms the fourth figure. Structure.

A main feature of the present invention is that, in steps S10 to S20, patterning dry film plating is used to form the first line and the micro copper window and define the target point A, and the first line and the micro after removing the carrier board in step S22. The copper window forms a buried circuit, whereby the adhesive layer is exposed and just in the micro copper window between any two copper pads, and then the wavelength of the laser beam is difficult to be absorbed by copper, so When the beam is irradiated on the two copper pads and the adhesion layer, only the adhesion layer is penetrated to form a micro-via, so that the aperture of the micro-via is the same as the micro-copper window in the first line, and is not covered by the reticle beam. Path limit.

In addition, the first line of the present invention is a buried line, so that the micro-via holes of the adhesion layer that will form the micro-vias are not covered by the metal layer, so the laser can directly penetrate the adhesion layer to form micro-vias; However, the entire surface of the insulating layer of the prior art is covered by a metal layer. Since it is difficult for the laser to penetrate the metal layer, it is necessary to first open the copper window in the metal layer through image transfer, and then use the laser to drill the insulating layer. However, after laser drilling, the hole diameter expansion problem will still be caused by the Desmear process, and the finished product pitch can only reach 140 μm .

The first line and the micro copper window of the present invention are formed by patterning dry film plating on the metal layer, and the first line is formed by patterning the dry film, and the line of the first line is in terms of the existing process capability. The width and spacing can be easily controlled below 50 μm . In addition, in the process of fabricating the first line and the copper window, only the metal layer and the carrier plate of the same metal material are processed, and the process parameters are easy to control and easy to process, so the line width of the first line and the spacing of the first line are Can be precisely controlled.

Since the micro copper window in the first line formed by the patterned electroplating dry film can be easily controlled below 50 μm , the diameter of the formed micro via hole can be greatly reduced to 50 μm after laser drilling. In the following, the micro-via hole diameter is greatly reduced, so that the arrangement density of the micro-via holes can be greatly increased, thereby effectively meeting the requirements of embedding components with high-density pins, and the present invention uses a laser to open micro-vias and uses The target layer on the same layer as the micro-via hole is used to fix the component and perform laser drilling by means of optical alignment, thereby effectively improving the precision of the workpiece, and the circuit for embedding the high-density pin component is provided by the present invention. The manufacturing method and structure of the board, the diameter of the micro-via hole and the diameter of the copper pad can be reduced to less than 10 μm , and the number of pins of the embedded component is up to 20,000.

It has not been seen in the published publications, periodicals, magazines, media, and exhibition fields in the technology of the present invention, and thus has novelty and can be implemented through the current technical bottlenecks, and is indeed progressive. In addition, the present invention can solve the problems of the conventional technology, improve the overall use efficiency, and can achieve the value of industrial utilization.

The above is only a preferred embodiment for explaining the present invention, and is not intended to limit the present invention in any way, and any modifications or alterations to the present invention made in the spirit of the same invention. All should still be included in the scope of the intention of the present invention.

S10~S28‧‧‧Steps

Claims (9)

A circuit board manufacturing method capable of embedding a high pin number component, comprising: plating a metal layer on a carrier plate; forming a first line on one side of the metal layer, the first circuit comprising a plurality of copper pads; covering a photoresist layer on the metal layer and the first line; patterning the photoresist layer such that the first line is only covered by the patterned photoresist layer; etching the photoresist after being patterned Layering the metal layer and removing the photoresist layer; forming an adhesive layer on a portion of the copper pad of the copper pad, and then fixing an element to the adhesive layer, the component having a plurality of I/O a pin, wherein each of the copper pads of the copper pad corresponding to the component has a micro copper window, and each micro copper window corresponds to each I/O pin, and does not correspond to the component. A copper window is disposed between the copper pads, and one of the copper windows is set as a target point; an insulating layer and a second metal layer are sequentially formed on the first line and the component, and the carrier plate is removed and Etching the metal layer until the adhesive layer corresponds to the portion of the micro copper window and the insulating layer corresponds to the copper window Partially exposing; optically aligning the target, and inserting the adhesive layer between the I/O pin and the micro copper window by a drilling method to form a micro through hole in the I/O a through hole is formed on the pin and through the portion of the insulating layer and the second metal layer corresponding to the copper window; a through hole is formed in the micro via and the via hole; and the etching is removed by etching A portion of the metal layer is exposed until the first line to form a plurality of microvias and a plurality of vias. The method for fabricating a circuit board capable of embedding a high pin number component according to the first aspect of the patent application, wherein the carrier board is made of a metal material. According to the method of fabricating a board capable of embedding a high pin number component according to the first aspect of the patent application, the first line is formed by a pattern dry plating method. A method of fabricating a circuit board capable of embedding a high pin number component according to claim 1, wherein the photoresist layer is a dry film photoresist or a wet film photoresist. A method of fabricating a circuit board capable of embedding a high pin number component according to the first aspect of the patent application, wherein the component is disposed using the target A for alignment. A circuit board manufacturing method capable of embedding a high pin number component according to the first aspect of the patent application, wherein the component is an active component or a passive component. The method for fabricating a circuit board capable of embedding a high pin number component according to claim 1, wherein the adhesive layer is formed by a dispensing technique, a screen printing technique or a bonding method, wherein the bonding layer is formed The adhesive layer in the form of a sheet or a roll is attached to the first line, and the portion of the adhesive layer corresponding to the copper window is also penetrated to form the through hole. A method of fabricating a circuit board capable of embedding a high pin number component according to claim 1 of the patent application, wherein the drilling method is a laser drilling. The method for fabricating a circuit board capable of embedding a high pin number component according to the first aspect of the patent application, wherein the micro through hole is a blind hole or a buried hole.