TWI708337B - Electronic package and manufacturing method thereof and cooling part - Google Patents

Abstract

This invention provides an electronic package which bonds a heat dissipating member with an electronic component disposed on a carrier by a heat conducting interface layer, and the heat dissipating member has a concave-convex structure to increase the heat dissipation area of the heat conducting interface layer, so that the heat dissipating member has better heat dissipation effect.

Description

Electronic package and its manufacturing method and heat sink

The invention relates to a packaging structure, in particular to an electronic packaging with a heat sink and its manufacturing method.

With the increase in the function and processing speed of electronic products, the semiconductor chip as the core component of the electronic product needs to have higher density of electronic components (Electronic Components) and electronic circuits (Electronic Circuits), so the semiconductor chip will A larger amount of heat energy is generated subsequently. Furthermore, since the traditional encapsulant system for coating the semiconductor chip is a poor heat transfer material with a thermal conductivity of only 0.8Wm-1k-1 (that is, the heat dissipation efficiency is poor), if the semiconductor chip cannot be effectively dissipated The heat generated will cause damage to semiconductor chips and product reliability issues.

Therefore, in order to quickly dissipate heat to the outside, the industry usually configures a heat sink (Heat Sink or Heat Spreader) in a semiconductor package. The heat sink is usually made of heat-dissipating glue, such as Thermal Interface Material (TIM). It is bonded to the back of the chip to dissipate the heat generated by the semiconductor chip through the heat sink and the heat sink. Moreover, the top surface of the heat sink is usually exposed to the packaging compound or directly exposed to the atmosphere to achieve better heat dissipation.

As shown in Figure 1, the conventional method for manufacturing a semiconductor package 1 is to first place a semiconductor chip 11 with its active surface 11a on a package substrate 10 by flip chip bonding (ie through conductive bumps 110 and primer 111). Then, a heat sink 13 is reflow-bonded to the non-acting surface 11b of the semiconductor chip 11 with its top sheet 130 through the TIM layer 12 (which includes a solder layer and flux), and the supporting legs of the heat sink 13 131 is mounted on the packaging substrate 10 through the adhesive layer 14. Then, an encapsulation molding operation is performed to provide an encapsulant (not shown in the figure) to cover the semiconductor chip 11 and the heat sink 13, and the top sheet 130 of the heat sink 13 exposes the encapsulant.

During operation, the heat generated by the semiconductor chip 11 is conducted to the top sheet 130 of the heat sink 13 via the inactive surface 11b and the TIM layer 12 to dissipate heat to the outside of the semiconductor package 1.

However, in the conventional semiconductor package 1, the top sheet 130 of the heat sink 13 has a flat surface, resulting in a limited heat dissipation area, resulting in limited heat dissipation effect, and it is difficult to meet the high heat dissipation requirements of the semiconductor package 1.

Furthermore, in the manufacturing process of the conventional semiconductor package 1, usually after the adhesive layer 14 is heated and glued on the package substrate 10, the supporting legs 131 of the heat sink 13 are directly adhered, and the adhesive layer 14 is cooled down. The adhesive force makes the package substrate 10 and the heat sink 13 adhere to each other, but the adhesive layer 14 is prone to generate bubbles during the heating process, resulting in poor structural strength of the adhesive layer 14 and easily causing the heat sink 13 to fall off.

In addition, when faced with the need to thin the thickness of the semiconductor package 1 and increase the area, the deformation (ie, the degree of warpage) between the heat sink 13 and the TIM layer 12 due to the difference in the coefficient of thermal expansion (CTE Mismatch) is more obvious , And when the amount of deformation is too large, delamination between the top sheet 130 of the heat sink 13 and the TIM layer 12 (or with the semiconductor wafer 11) is likely to occur, which not only causes heat conduction effects Decrease, and cause the appearance of the semiconductor package 1 to be defective, and even seriously affect the reliability of the product.

Therefore, how to overcome the above-mentioned problems of the conventional technology has actually become a problem that the industry urgently needs to overcome.

In view of the various deficiencies of the above-mentioned conventional technologies, the present invention provides an electronic package, which includes: a carrier; at least one electronic component disposed on the carrier; and a heat sink including a heat sink and The support leg on the heat sink, the heat dissipation system is coupled to the electronic component through a thermal interface layer, and the support leg is coupled to the carrier to support the heat sink, wherein the heat dissipation system is formed with a concave-convex structure, which It has a plurality of convex parts and a concave part located between the two convex parts.

The present invention also provides a manufacturing method of an electronic package, which includes: providing a heat sink, which includes a heat sink and a supporting leg provided on the heat sink, wherein the heat sink system is formed with a concave-convex structure having a plurality of convex portions And the concave portion located between the two convex portions; and the heat sink is combined with the supporting leg on the carrier, and at least one electronic component is arranged on the carrier, and the heat sink is provided with a thermal interface layer Bonded to the electronic component.

In the aforementioned manufacturing method, the thickness of the electronic package is controlled by a positioning device.

In the foregoing manufacturing method, the air extraction operation is performed when the heat sink is combined with the carrier.

In the aforementioned electronic package and its manufacturing method, the convex portion is ridge-shaped, the bottom side of the convex portion has opposite first and second sides, and the width of the first side is different from that of the The width of the second side. For example, the first side and the second side of the protrusions are arranged in a staggered manner.

In the aforementioned electronic package and its manufacturing method, the heat dissipation system defines a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the second section is formed with A wall structure located between the supporting foot and the concave-convex structure. For example, the wall structure is combined with the electronic component by a bonding material, and the bonding material is extended to the concave-convex structure so that the bonding material contacts the thermally conductive interface layer. Alternatively, the second section of the heat sink, the carrier, the electronic component, and the supporting leg form an air space, and the recess is formed with an air chamber, so that the air pressure of the air chamber is less than that of the air space Air pressure.

In the aforementioned electronic package and its manufacturing method, an air chamber is formed between the thermally conductive interface layer and the recess.

In the aforementioned electronic package and its manufacturing method, the shape system of the thermal interface layer complements the shape of the concave-convex structure.

In the aforementioned electronic package and its manufacturing method, the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the second section is formed by The thermal interface layer combines the electronic component and the carrier.

In the aforementioned electronic package and its manufacturing method, the roughness of at least one surface of the heat sink is greater than 1.5 μm to form the uneven structure.

In the aforementioned electronic package and its manufacturing method, the convex portion of the concave-convex structure is a convex strip or a bump.

In the aforementioned electronic package and its manufacturing method, the concave portion of the concave-convex structure is a groove or a cavity.

The present invention further provides a heat dissipating element, comprising: a heat dissipating body, wherein the heat dissipating system is formed with a concave-convex structure, which has a plurality of convex portions and a concave portion located between the two convex portions; and at least one supporting leg, which is arranged vertically On the heat sink.

In the aforementioned heat sink, the convex portion is ridge-shaped. For example, the bottom side of the convex portion has a first side and a second side opposite to each other, and the width of the first side is smaller than the width of the second side. Further, the first side and the second side of the plurality of convex portions are arranged in a staggered manner.

In the aforementioned heat dissipation element, the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the second section is formed with the supporting leg The wall structure between the uneven structure.

In the aforementioned heat sink, the roughness of at least one surface of the heat sink is greater than 1.5 micrometers to form the uneven structure.

In the aforementioned heat sink, the convex portion of the concave-convex structure is a convex strip or a bump.

In the aforementioned heat sink, the concave portion of the concave-convex structure is a groove or a cavity.

It can be seen from the above that the electronic package and its manufacturing method and heat sink of the present invention mainly use the design of the heat sink with a concave-convex structure to increase the heat dissipation area of the heat sink. Therefore, compared with the conventional technology, the heat sink of the present invention The device has better heat dissipation effect to meet the high heat dissipation requirement of the electronic package.

Furthermore, the present invention uses the air extraction device to perform the air extraction operation so that air bubbles are not easily formed in the bonding material during the heating process. Therefore, compared with the prior art, the bonding material of the present invention has better structural strength. Therefore, the heat sink will not fall off.

In addition, the present invention uses the staggered arrangement of the protrusions to effectively disperse the thermal stress, so as to prevent the thermal stress from being concentrated on one side of the heat sink. Therefore, the manufacturing method of the present invention can effectively control the deformation (warping) of the heat sink. Curvature), thus preventing the problem of delamination between the heat sink and the thermal interface layer.

In addition, the present invention uses the design of the air chamber to generate the adsorption force, so that the fixing effect of the heat dissipating element to the supporting element can be enhanced.

1‧‧‧Semiconductor package

10‧‧‧Packaging substrate

11‧‧‧Semiconductor chip

11a‧‧‧working surface

11b‧‧‧Inactive surface

110‧‧‧Conductive bump

111‧‧‧ Primer

12‧‧‧TIM layer

13‧‧‧Radiator

130‧‧‧Top Film

131‧‧‧Support feet

14‧‧‧Adhesive layer

2‧‧‧Electronic package

2a‧‧‧Radiator

20‧‧‧Radiator

20a‧‧‧Section 1

20b‧‧‧Second section

200,500a,500b,500c,601a,602a,603a,604a,605a,606a,607a,601b,602b,603b,604b,601c,602c,603c,604c‧‧‧Concave-convex structure

201,201’,201”‧‧‧Protrusion

201a‧‧‧First side

201b‧‧‧Second side

202,202’‧‧‧Recess

203‧‧‧Wall structure

21‧‧‧Support feet

210‧‧‧Cave

22‧‧‧Thermal Interface Layer

23,23’,43a,43b,43c,43d‧‧‧binding material

24‧‧‧Carrier

24a‧‧‧Crystal side

24b‧‧‧Ball planting side

25‧‧‧Electronic components

26‧‧‧Conductive element

27‧‧‧Gold layer

3‧‧‧Positioning device

30‧‧‧Elastic element

31‧‧‧First pressure plate

310‧‧‧First positioning part

32‧‧‧Second pressure plate

320‧‧‧Second positioning part

33‧‧‧Drive

4‧‧‧Air extraction device

4a‧‧‧Cover

40‧‧‧Trachea

41‧‧‧Exhaust pipe

5‧‧‧Heating device

A‧‧‧Air Chamber

B‧‧‧Bottom side

C‧‧‧Location

D‧‧‧Width

e‧‧‧Concave

H‧‧‧Distance

h‧‧‧total thickness

h1‧‧‧Thickness

h2‧‧‧Thickness

P‧‧‧Interval

R‧‧‧tip

r‧‧‧tip

S,S’‧‧‧Air Space

t‧‧‧Pitch

W‧‧‧Width

w1‧‧‧Width

w2‧‧‧Width

X‧‧‧Arrow direction

Figure 1 is a schematic cross-sectional view of a conventional semiconductor package.

2A to 2D are schematic cross-sectional views of the manufacturing method of the electronic package of the present invention.

Figure 2A' is a partial perspective view of Figure 2A.

Figure 2A" is a partial enlarged view of Figure 2A'.

Figure 2C' is a schematic diagram of the process equipment configuration applied to Figure 2C.

Figure 2D' is a partial perspective view of Figure 2D.

Figure 2E is a partial schematic diagram of another embodiment of the 2D manufacturing method.

Figure 3 is a schematic cross-sectional view of the electronic package of the present invention.

Figure 3A is a schematic cross-sectional view taken along the line a-a in Figure 3.

Figure 3B is a schematic cross-sectional view taken along line b-b in Figure 3.

Figure 3C is a schematic cross-sectional view taken along line c-c in Figure 3.

Figure 3D is a schematic cross-sectional view taken along line d-d in Figure 3.

Figures 4A to 4E are partial cross-sectional views of other different embodiments of Figure 3.

5A to 5C are partial perspective views of other different embodiments of the concave-convex structure of the present invention.

Figures 6A-1 to 6A-7 are partial perspective views of other different embodiments of the concave-convex structure of the present invention.

Figures 6B-1 to 6B-4 are partial perspective views of other different embodiments of the concave-convex structure of the present invention.

6C-1 to 6C-4 are partial perspective views of other different embodiments of the concave-convex structure of the present invention.

Figure 7 is a partial perspective view of another embodiment of the concave-convex structure of the present invention.

The following specific examples illustrate the implementation of the present invention. Those familiar with the art can easily understand the other advantages and effects of the present invention from the contents disclosed in this specification.

It should be noted that the structures, proportions, sizes, etc. shown in the drawings in this manual are only used to match the contents disclosed in the manual for the understanding and reading of those familiar with the art, and are not intended to limit the implementation of the present invention Therefore, it does not have any technical significance. Any structural modification, proportional relationship change, or size adjustment should still fall within the scope of the present invention without affecting the effects and objectives that can be achieved. The technical content disclosed by the invention can be covered. At the same time, the terms such as "on", "first", "second" and "one" cited in this manual are only for ease of description and are not used to limit the implementation of the present invention. The change or adjustment of the scope and the relative relationship shall also be regarded as the scope within which the present invention can be implemented without substantially changing the technical content.

2A to 2D are schematic cross-sectional views of the manufacturing method of the electronic package 2 of the present invention.

As shown in Figures 2A and 2A', a heat sink 2a is provided, which includes a heat sink 20 and at least one supporting leg 21 provided on the heat sink 20, wherein a concave-convex structure 200 is formed on the surface of the heat sink 20 , It has a plurality of convex portions 201, 201', 201" and a plurality of concave portions 202, 202' located between the plurality of convex portions 201, 201', and some of the convex portions 201, 201' are ridge-shaped (the concave portion 202 is ravine-shaped), and part The convex portion 201" is in the shape of a fin or a rectangular sheet to form the concave portions 202, 202' of different shapes correspondingly. Then, a thermally conductive interface layer 22 is formed on the heat sink 20.

In this embodiment, the heat sink 20 is defined with a first section 20a and a second section 20b adjacent to each other, wherein the first section 20a is formed with the concave-convex structure 200, and the second section 20b is formed with the supporting foot 21 and at least one wall structure 203 between the supporting foot 21 and the concave-convex structure 200, and a recess 210 is formed between the supporting foot 21 and the wall structure 203, wherein the The height of the wall structure 203 is greater than the height of the convex portion 201, 201', 201", so that the adjacent wall structure 203 and the convex portion 201" form a step shape.

Furthermore, the minimum width D of the concave portions 202, 202' is less than 1mm, and the top side of the ridge-shaped convex portions 201, 201' is the tip R, and the width W is less than 3mm (as shown in Figure 2A"), and the The bottom side B of the ridge-shaped protrusions 201, 201' has a first side (short side) 201a and a second side (long side) 201b opposite to each other. The width w1 of the first side 201a is smaller than the second side. side The width w2 of the side 201b. For example, the bottom side B is a tapered surface (such as the shape of one part C of the first section 20a in Figure 2A shown in Figure 2A').

In addition, at least two of the ridge-shaped protrusions 201, 201' are based on the first side 201a and the second side 201b of the bottom side B being arranged in opposite directions, that is, the short side of one of the ridge-shaped protrusions 201 The (first side 201a) adjoins the long side (second side 201b) of the other ridge-shaped convex portion 201' in a staggered arrangement, as shown in Figure 2A'.

In addition, the thermally conductive interface layer 22 is a TIM, such as a low-temperature melting thermally conductive material, which can be formed of solid metal or liquid metal (such as solder material), and is filled in the recesses 202, 202'.

As shown in FIG. 2B, bonding materials 23, 23' are formed on the sheet-shaped convex portion 201" and the supporting leg 21, and a carrier 24 with at least one electronic component 25 is provided on the crystal mounting side 24a.

In this embodiment, the carrier 24 is, for example, a package substrate with a core layer and a circuit structure or a coreless circuit structure, which forms a circuit layer on the dielectric material, such as fan-out ( fan out) type redistribution layer (RDL). It should be understood that the supporting member 24 can also be other supporting structures capable of supporting electronic components such as chips, such as leadframes or silicon interposers, and is not limited to the above.

Furthermore, the electronic component 25 is an active component, a passive component, or a combination of the two, etc., wherein the active component is, for example, a semiconductor chip, and the passive component is, for example, a resistor, a capacitor, and an inductor. For example, the electronic component 25 is electrically connected to the circuit layer of the carrier 24 in a flip chip method or a wire bonding method. However, the manner in which the electronic component 25 is electrically connected to the carrier 24 is not limited to the above.

In addition, the bonding material 23, 23' is a glue material, an adhesive material or a metal material, and it is different from the material of the thermally conductive interface layer 22.

As shown in Figure 2C, the heat sink 2a is bonded to the crystal placement side 24a of the carrier 24 with its supporting legs 21 through the bonding material 23', and the wall structure 203 and the sheet-like protrusion 201" The electronic component 25 is combined with the bonding material 23, and the heat sink 20 is combined with the electronic component 25 through the thermal interface layer 22.

In this embodiment, part of the recess 202' is not filled with the thermal interface layer 22, so that an air chamber A is formed in the recess 202'. For example, the volume of the air chamber A is greater than or equal to the expansion amount of the thermally conductive interface layer 22 at a predetermined temperature (eg, 260° C.). For example, during the manufacturing method of the present invention, the temperature rises and falls between 25°C and 240°C, so the volume of the air chamber A needs to be higher than the expansion amount of the thermal interface layer 22 at 240°C, otherwise the thermal interface layer 22 The recess 202' will be filled up and the air chamber A will disappear.

Furthermore, as shown in FIG. 2C', the joining process of the heat sink 2a and the carrier 24 can be performed by a positioning device 3 and an air extraction device 4. For example, the heat sink 2a can be pressed onto the carrier 24 and the electronic device 25 by the positioning device 3, and before the pressing action, the air extraction device 4 can be used for air extraction (such as For vacuum operation, the vacuum value is about 1~10-7mm Hg).

Specifically, during the pressing process, the positioning device 3 is connected to the first pressing plate 31 by the driving member 33 to move the first pressing plate 31 under pressure, and the first pressing plate 31 is buffered relative to the first pressing plate 31 by an elastic element 30 such as a spring. The displacement of the two pressing plates 32 makes the first positioning portion 310 of the first pressing plate 31 abut against the second positioning portion 320 of the second pressing plate 32 to control the distance H between the first pressing plate 31 and the second pressing plate 32 , At this time, the carrier 24 provided on the first pressure plate 31 and the second pressure plate The heat sink 2a on the 32 will be relatively positioned, thereby controlling the thickness h1 of the bonding material 23' of the supporting leg 21 and the thickness h2 of the thermal interface layer 22, that is, the distance H is equal to the carrier 24 and the bonding material 23' The total thickness h of the three of the heat sink 2a and the heat sink 2a, and after pressing, the bonding material 23 at the wall structure 203 and part of the convex portion 201" can contact the thermally conductive interface layer 22, and the heat sink 20 The second section 20b, the supporting member 24, the electronic component 25 and the supporting leg 21 form an air space S.

On the other hand, when the carrier 24 and the heat sink 2a are positioned relative to each other, the positioning device 3 is first covered with the outer cover 4a of the air extraction device 4, and then at least one air pipe 40 of the air extraction device 4 is inserted Between the carrier 24 and the heat dissipating part 2a, and the exhaust pipe 41 is connected to the inside of the outer cover 4a to perform air extraction operation, thereby forming the air chamber A, and extracting the electronic device 25 and the heat dissipating part 2a The gas in the interval P (as shown in FIG. 2B) between the electronic device 25 and the concave-convex structure 200 can be lower than 1 atmosphere. Specifically, after the compression operation, the air pressure of the air chamber A is different from (if less than) the air pressure of the air space S. For example, the air pressure of the air chamber A is about 1-10 ^-7 mmHg, and the air The air pressure value of the space S is approximately greater than 760mmHg (that is, 1 atmosphere) to generate the adsorption force caused by the pressure difference, so that the heat sink 2a and the carrier 24 can be further combined with each other by air adsorption, thereby The bonding force between the heat sink 2a and the carrier 24 is increased.

It should be understood that the air extraction device 4 and the positioning device 3 can cooperate with each other (that is, while pressing down the first pressure plate 31, while extracting the gas between the electronic device 25 and the concave-convex structure 200), the air extraction The device 4 can provide an air source to the driving member 33 of the positioning device 3, so that the driving member 33 can be connected to the first pressing plate 31 in a suction manner.

In addition, after the air extraction operation (extraction of oxygen and volatile solvents) is performed, the heating device 5 is used to perform heating operation through the second pressing plate 32, so that the sintering of the thermally conductive interface layer 22 can be more uniform and firm, without the formation of bubbles In the thermal interface layer 22, not only can increase the adhesion, but also It can effectively reduce the thermal resistance of the thermal interface layer 22 and increase the thermal conductivity. During the heating process, the solvent of the bonding material 23, 23' is easy to volatilize outward (such as the arrow direction X), so no bubbles are formed in the The binding material is 23,23'.

On the other hand, since the air pressure between the electronic device 25 and the concave-convex structure 200 is lower than 1 atmosphere after the pressing operation, the thermal energy and airflow provided by the heating device 5 will not generate heat at the interval P By convection, the heating device 5 can uniformly provide heat energy to the thermally conductive interface layer 22 to avoid the problem of uneven temperature of the thermally conductive interface layer 22 during sintering.

It should be understood that the heating device 5, the air extraction device 4, and the positioning device 3 can be integrated on a machine, so that the requirements of automation equipment can be met.

As shown in FIG. 2D, a plurality of conductive elements 26 are formed on the ball-planting side 24b of the carrier 24.

In this embodiment, the conductive element 26 is a metal block such as a copper block, a solder bump, or a tin ball with a copper core. It should be understood that there are many types of the conductive elements, which are not limited to the above.

Furthermore, the distance t between the electronic component 25 and the tips R of the ridge-shaped protrusions 201, 201' of the heat sink 20 is at most 1 mm, and the shape of the thermally conductive interface layer 22 complements the shape of the uneven structure 200 (such as 2D' The mountain shape shown in the figure), so that the thermally conductive interface layer 22 also forms a ridge portion with a tip r, and the tip r of the thermally conductive interface layer 22 (or the tip R of the ridge-shaped protrusion 201, 201') is inclined to one side, The cross-sectional schematic diagram shown in Figure 3C or 3D.

In addition, the bonding material 23 located at the step-like place is L-shaped to increase the bonding effect of the bonding material 23, and the pressure difference between the inner and outer sides of the bonding material 23 (the air pressure of the air chamber A is less than the air pressure of the air space S) ), that is, the adsorption force to further increase the joining of the heat sink 2a to the carrier 24 Fixed effect. It should be understood that, in one embodiment, the top side of the sheet-shaped convex portion 201" may be formed with a concave surface e, such as the V shape shown in FIG. 2E, to increase the contact area of the bonding material 23, so that the bonding The bonding effect of the material 23 is better. Similarly, the end surface of the wall structure 203 can also be a concave surface (as shown in Figure 4D), or the end surface of the supporting leg 21 can also be a concave surface (not shown).

In addition, in order to improve the bonding strength between the thermally conductive interface layer 22 (TIM) and the electronic component 25, the surface of the electronic component 25 may be coated with gold (the so-called Coating Gold On Chip Back). Specifically, as shown in FIG. 2E, a gold layer 27 is formed on the surface of the electronic component 25 and the surface of the heat sink 20, and a flux is further added to facilitate the bonding of the thermal interface layer 22 to the On the gold layer 27.

Please refer to Figures 3 and 3A to 3D of the cross-sectional schematic diagrams of the electronic package 2 formed by the manufacturing method of the present invention in different directions. The present invention mainly uses the design of the heat sink 2a with a concave-convex structure 200 to increase the heat sink With a heat dissipation area of 20, the heat sink 2a of the present invention has a better heat dissipation effect than the conventional technology, so as to meet the high heat dissipation requirements of the electronic package 2. Further, the shape system of the thermally conductive interface layer 22 complements the shape of the concave-convex structure 200, so that the tip r of the thermally conductive interface layer 22 is easier to thermally saturate due to its small volume (or heat capacity), so the tip r of the thermally conductive interface layer 22 The heat in the place is easily transferred to the heat sink 20 (such as the bottom side B of the convex portion 201, 201' or the bottom end of the concave portion 202), and because the heat capacity of the heat sink 20 is large, the heat energy can be quickly discharged to the external environment .

Furthermore, in the manufacturing method of the present invention, the air extraction device 4 is used for air extraction first, and then the heating operation is performed, so that during the heating process, the solvent of the bonding material 23, 23' is easy to volatilize outwards, and therefore it is not easy to form bubbles. In the bonding materials 23, 23' and the thermal interface layer 22, it is compared with In the prior art, the bonding material 23, 23' of the present invention and the thermal interface layer 22 have better structural strength, so the heat sink 2a will not fall off.

In addition, the manufacturing method of the present invention uses the staggered arrangement of the long and short sides of the protrusions 201, 201' to effectively disperse the thermal stress, so as to prevent the thermal stress from being concentrated on one of the bottom sides B of the protrusions 201, 201'. The manufacturing method of the invention can effectively control the amount of deformation (warpage) of the heat sink 20, thus preventing the problem of delamination between the heat sink 20 and the thermally conductive interface layer 22, which not only improves the thermal conductivity, but also prevents Affect the appearance of the electronic package 2. In other words, if the bottom sides B of the adjacent protrusions 201, 201' are arranged in such a way that the long sides are aligned with the long sides, the amount of deformation of the heat sink 20 is likely to be too large.

In addition, the manufacturing method of the present invention uses a design that the air pressure of the air chamber A is lower than the air pressure of the air space S to generate adsorption force, so that the fixing effect of the heat sink 2a to the carrier 24 can be enhanced.

In other embodiments, the bonding material 23 can increase or decrease the deployment range as required. The bonding material 43a shown in FIG. 4A extends to the concave portion 202', and the bonding material 43b shown in FIG. 4B does not touch the convex portion. Part 201", as shown in Figure 4C, the bonding material 43c extends into the air space S to change the scope of the air space S'(or outwardly beyond the vertical projection range of the wall structure 203), or as shown in Figure 4D The shown bonding material 43d is only located within the vertical projection range of the wall structure 203.

In other embodiments, the concave-convex structure of the first section 20a can be designed according to heat dissipation requirements. As shown in FIG. 5A, the first section 20a is a rectangular body, and the surface of the rectangular body is roughened to make the surface roughness Ra greater than 1.5 micrometers (um) to form a concave-convex structure 500a. As shown in FIG. 5B, the first section 20a is a trapezoid, and the slope of the trapezoid is roughened to make its surface roughness Ra>1.5um to form a concave-convex structure 500b. As shown in Figure 5C, the The first section 20a is a rectangular body, and the surface of the rectangular body is concave-convexed to form an irregular shape on the surface to serve as the concave-convex structure 500c.

In addition to the roughening process, the uneven structure can also be designed in a strip method. As shown in Figures 6A-1, 6A-2, 6A-3, 6A-4, 6A-5, 6A-6, and 6A-7, the first section 20a is rectangular, and is formed on the heat dissipation surface At least one (such as semicircular tubular, rectangular, triangular, curved, trapezoidal or other shapes) grooves to form (such as rectangular, wavy, triangular sheet, curved, triangular pillars or other shapes) protruding strips for use as Concavo-convex structure 601a, 602a, 603a, 604a, 605a, 606a, 607a. As shown in Fig. 6B-1, 6B-2, 6B-3 or 6B-4, the first section 20a is rectangular, and at least one (such as cylindrical, hemispherical, cone-shaped Shape, rectangle or other shapes) bumps to form concave-convex structures 601b, 602b, 603b, 604b. Also as shown in Figure 6C-1, 6C-2, 6C-3 or 6C-4, the first section 20a is a rectangular body, and at least one (such as a circular hole, a hemispherical hole) is formed on the heat dissipation surface , Cone-shaped hole, rectangular hole-shaped or other shapes) recesses to form concave-convex structures 601c, 602c, 603c, and 604c.

It should be understood that the concave-convex structure can also be used in conjunction with the roughening process and the strip method, as shown in FIG. 7.

The present invention further provides an electronic package 2 comprising: a carrier 24, an electronic component 25 arranged on the carrier 24, and a heat sink 2a combined with the electronic component 25.

The heat dissipating element 2a includes a heat dissipating body 20 and at least one supporting leg 21 provided on the heat dissipating body 20. The heat dissipating body 20 is combined with the electronic component 25 through a thermally conductive interface layer 22, and the supporting leg 21 is Combined with the carrier 24 to support the heat sink 20, wherein the heat sink 20 is formed with a concave-convex structure 200, which has a plurality of convex portions 201, 201', 201" and the convex portion 201, 201', 201" Recesses 202, 202'.

In one embodiment, part of the convex portion 201, 201' is ridge-shaped, and its bottom side B has a first side 201a and a second side 201b opposite to each other, and the first side (short side) 201a The width w1 is smaller than the width w2 of the second side (long side) 201b. For example, the long and short sides of the protrusions 201, 201' are staggered.

In one embodiment, the shape system of the thermal interface layer 22 complements the shape of the concave-convex structure 200.

In one embodiment, the thermally conductive interface layer 22 does not fill the recess 202', so that an air chamber A is formed in the recess 201".

In one embodiment, the heat sink 20 is defined with a first section 20a and a second section 20b adjacent to each other, the first section 20a is formed with the concave-convex structure 200, and the second section 20b There is a wall structure 203 between the supporting leg 21 and the concave-convex structure 200.

For example, the wall structure 203 is combined with the electronic component 25 by the bonding material 23, and the supporting leg 21 is also combined with the carrier 24 by the bonding material 23'. Furthermore, the bonding material 23 extends to the convex portion 201 ″ of the concave-convex structure 200 so that the bonding material 23 contacts the thermally conductive interface layer 22.

On the other hand, the second section 20b of the radiator 20 (including the wall structure 203 and the bonding material 23), the carrier 24, the electronic component 25, and the supporting leg 21 (including the bonding material 23') form one The air space S is such that the air pressure of the air chamber A is lower than the air pressure of the air space S.

In other embodiments, as shown in FIG. 4E, the second section 20b of the heat sink 20 may not form the wall structure 203, so that the second section 20b is combined with the electronic component 25 through the thermally conductive interface layer 22 The carrier 24 and the air space S can fill the thermally conductive interface layer 22 (that is, there is no air space S) without filling the air chamber A.

It should be understood that, as shown in FIGS. 4A to 4E, a primer 45 for flip-chip processing can be formed around the electronic component 25 as required.

In one embodiment, the roughness of at least one surface of the heat sink 20 is greater than 1.5 microns to form the concave-convex structure 500a, 500b, 500c.

In one embodiment, the convex portions of the concave-convex structure 601a, 602a, 603a, 604a, 605a, 606a, 607a, 601b, 602b, 603b, and 604b are convex strips or bumps.

In one embodiment, the concave portions of the concave-convex structure 601a, 602a, 603a, 604a, 605a, 606a, 607a, 601c, 602c, 603c, 604c are grooves or cavities.

In summary, the electronic package of the present invention and its manufacturing method are designed with a concave-convex structure of the heat sink to increase the heat dissipation area of the heat sink. Therefore, the heat sink of the present invention has a better heat dissipation effect. Meet the high heat dissipation requirements of the electronic package.

Furthermore, the present invention uses air extraction to avoid the formation of bubbles in the bonding material, so the bonding material of the present invention has a better bonding effect.

In addition, the heat sink of the present invention effectively disperses the thermal stress through the staggered arrangement of the protrusions, so that the heat sink can prevent stress concentration and excessive warping of the heat sink.

In addition, the present invention uses the design of the air chamber to generate adsorption force to improve the fixing effect of the heat sink.

The above-mentioned embodiments are used to exemplify the principles and effects of the present invention, but not to limit the present invention. Anyone who is familiar with the art can modify the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be listed in the scope of patent application described later.

2‧‧‧Electronic package

2a‧‧‧Radiator

20‧‧‧Radiator

200‧‧‧Concave-convex structure

201,201’,201”‧‧‧Protrusion

202,202’‧‧‧Recess

203‧‧‧Wall structure

21‧‧‧Support feet

22‧‧‧Thermal Interface Layer

23,23’‧‧‧Combined material

24‧‧‧Carrier

25‧‧‧Electronic components

26‧‧‧Conductive element

A‧‧‧Air Chamber

S‧‧‧Air Space

Claims (42)

An electronic package includes: a carrier; at least one electronic component arranged on the carrier; and a heat dissipating element including a heat sink and a supporting leg provided on the heat sink, and the heat dissipation system uses The thermal interface layer is coupled to the electronic component, and the supporting leg is coupled to the carrier to support the heat sink, wherein the heat dissipation system is integrally formed with a solid concave-convex structure from its surface, which has a plurality of convex portions and any Two concave parts between the convex parts. The electronic package described in item 1 of the scope of patent application, wherein the convex portion is ridge-shaped. According to the electronic package described in claim 2, wherein the bottom side of the convex portion has a first side and a second side opposite to each other, and the width of the first side is different from that of the second side. The width of the sides. The electronic package described in item 3 of the scope of patent application, wherein the first side and the second side of the plurality of convex portions are arranged in a staggered manner. For the electronic package described in item 1 of the scope of patent application, the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the first section The second section is formed with a wall structure between the supporting leg and the concave-convex structure. The electronic package described in item 5 of the scope of patent application, wherein the wall structure is combined with the electronic component by a bonding material. According to the electronic package described in item 6 of the scope of the patent application, the bonding material further extends to the concave-convex structure. According to the electronic package described in item 6 of the scope of patent application, the bonding material is in contact with the thermally conductive interface layer. According to the electronic package described in item 5 of the scope of patent application, wherein the second section of the heat sink, the carrier, the electronic component and the supporting leg form an air space. For the electronic package described in item 9 of the scope of patent application, an air chamber is formed in the recessed portion so that the air pressure of the air chamber is lower than the air pressure of the air space. According to the electronic package described in claim 1, wherein an air chamber is formed between the thermally conductive interface layer and the recess. According to the electronic package described in item 1 of the scope of patent application, the shape system of the thermally conductive interface layer complements the shape of the concave-convex structure. For the electronic package described in item 1 of the scope of patent application, the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the first section The two sections combine the electronic component and the carrier through the thermal interface layer. According to the electronic package described in claim 1, wherein the roughness of at least one surface of the heat sink is greater than 1.5 microns to form the uneven structure. According to the electronic package described in item 1 of the scope of patent application, wherein the convex portion of the concave-convex structure is a convex strip or a bump. According to the electronic package described in item 1 of the scope of patent application, the concave portion of the concave-convex structure is a groove or a cavity. A manufacturing method of electronic packaging includes: A heat dissipation element is provided, which includes a heat dissipation body and a supporting leg provided on the heat dissipation body, wherein the heat dissipation system integrally forms a solid concave-convex structure from the surface of the heat dissipation system, and has a plurality of convex portions and a portion between the two convex portions. Concave portion; and the heat sink is combined with its supporting leg on a carrier, and at least one electronic component is arranged on the carrier, and the heat sink is coupled to the electronic component through a thermally conductive interface layer. The method for manufacturing an electronic package as described in item 17 of the scope of patent application, wherein the convex portion is ridge-shaped. The method for manufacturing an electronic package as described in item 18 of the scope of patent application, wherein the bottom side of the convex portion has a first side and a second side opposite to each other, and the width of the first side is different from the The width of the second side. According to the manufacturing method of the electronic package described in item 19 of the scope of patent application, the first side and the second side of the plurality of protrusions are arranged in a staggered manner. The method for manufacturing an electronic package as described in item 17 of the scope of patent application, wherein the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and The second section is formed with a wall structure between the supporting leg and the concave-convex structure. According to the method for manufacturing the electronic package described in item 21 of the scope of patent application, the wall structure is combined with the electronic component by a bonding material. The method for manufacturing an electronic package as described in item 22 of the scope of patent application, wherein the bonding material is extended to the concave-convex structure. According to the manufacturing method of the electronic package described in item 22 of the scope of patent application, the bonding material is in contact with the thermally conductive interface layer. According to the method for manufacturing an electronic package described in item 21 of the scope of patent application, wherein the second section of the heat sink, the carrier, the electronic component and the supporting leg form an air space. For the method of manufacturing an electronic package described in item 25 of the scope of patent application, an air chamber is formed in the concave portion so that the air pressure of the air chamber is lower than the air pressure of the air space. According to the method for manufacturing an electronic package as described in item 17 of the scope of patent application, an air chamber is formed between the thermally conductive interface layer and the recess. The method for manufacturing an electronic package as described in the scope of patent application, wherein the shape system of the thermal interface layer complements the shape of the concave-convex structure. The method for manufacturing an electronic package as described in item 17 of the scope of patent application, wherein the heat dissipation system is defined with a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and The second section combines the electronic component and the carrier through the thermal interface layer. The manufacturing method of the electronic package as described in item 17 of the scope of patent application includes controlling the thickness of the electronic package by a positioning device. For example, the manufacturing method of the electronic package described in item 17 of the scope of the patent application includes the exhausting operation when the heat sink is combined with the carrier. The method for manufacturing an electronic package as described in the scope of patent application, wherein the roughness of at least one surface of the heat sink is greater than 1.5 microns to form the uneven structure. Such as the method for manufacturing an electronic package described in item 17 of the scope of patent application, wherein the convex portion of the concave-convex structure is a convex strip or a bump. The method for manufacturing an electronic package as described in item 17 of the scope of patent application, wherein the concave portion of the concave-convex structure is a groove or a cavity. A heat sink, which includes: A heat dissipation body, wherein the heat dissipation system integrally forms a solid concavo-convex structure from the surface thereof, which has a plurality of convex portions and a concave portion located between the two convex portions; and at least one supporting leg is attached to the heat sink On the surface. For the heat sink described in item 35 of the scope of patent application, the convex portion is ridge-shaped. The heat sink according to item 36 of the scope of patent application, wherein the bottom side of the protrusion has a first side and a second side opposite to each other, and the width of the first side is smaller than that of the second side width. According to the 37th patent application, the first side and the second side of the plurality of protrusions are arranged in a staggered manner. For the heat sink described in item 35 of the scope of patent application, wherein the heat dissipation system defines a first section and a second section adjacent to each other, the first section is formed with the concave-convex structure, and the second section The section is formed with a wall structure between the supporting leg and the concave-convex structure. The heat dissipating element described in item 35 of the scope of patent application, wherein the roughness of at least one surface of the heat dissipating body is greater than 1.5 micrometers to form the uneven structure. For the heat sink described in item 35 of the scope of patent application, the convex part of the concave-convex structure is a convex strip or a bump. For the heat sink described in item 35 of the scope of patent application, wherein the concave portion of the concave-convex structure is a groove or a cavity.

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