The manufacturing method of circuit board assembly and circuit board assembly

Abstract

This application provides a method for manufacturing a circuit board assembly, including providing a first circuit substrate, including a first circuit layer and a dielectric layer, the first circuit layer including a cooling region recessed towards the dielectric layer, and the cooling region having a groove; providing a second circuit substrate; providing a first adhesive layer with an opening; stacking and pressing the first circuit substrate, the first adhesive layer, and the second circuit substrate together, exposing the cooling region to the opening; forming a through-hole penetrating the second circuit substrate and communicating with the opening; injecting coolant into the groove; bonding thermally conductive adhesive to the periphery of the cooling region; placing electronic components in the through-hole; and bonding the electronic components with thermally conductive adhesive to seal the opening. This application also provides a circuit board assembly with good heat dissipation.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology, and in particular to a method for manufacturing a circuit board assembly and the circuit board assembly itself. Background Technology

[0002] The CMOS chip in a camera module is typically embedded in the circuit board. During operation, the chip generates heat. Heat can be dissipated using the circuit board itself or metal reinforcing sheets, but these structures have high thermal resistance and small contact area, resulting in poor heat dissipation. Alternatively, a combination of copper pillars and coolant can be used for heat dissipation, but current manufacturing processes are complex and have low production feasibility. Summary of the Invention

[0003] In view of this, it is necessary to provide a method for manufacturing a circuit board assembly that is simple to manufacture and enables rapid heat dissipation, as well as the circuit board assembly itself.

[0004] This application provides a method for manufacturing a circuit board assembly, including providing a first circuit substrate, including a first circuit layer and a dielectric layer, the first circuit layer including a cooling region recessed towards the dielectric layer, and the cooling region having a groove; providing a second circuit substrate; providing a first adhesive layer with an opening; stacking and pressing the first circuit substrate, the first adhesive layer and the second circuit substrate together, exposing the cooling region to the opening; forming a through hole penetrating the second circuit substrate and communicating with the opening; injecting coolant into the groove; bonding thermally conductive adhesive to the periphery of the cooling region; placing electronic components in the through hole and bonding the electronic components with thermally conductive adhesive to seal the opening.

[0005] In some embodiments, the step of fabricating the first circuit substrate includes: providing a double-sided copper-clad laminate, including a dielectric layer and a first copper layer and a second copper layer located on opposite surfaces of the dielectric layer; forming blind vias on the first copper layer and the dielectric layer, with the second copper layer exposed in the blind vias; forming a metal layer in the blind vias, the metal layer further extending to the surface of the first copper layer around the blind vias, the metal layer also connecting to the second copper layer; and etching the first copper layer to form the first circuit layer.

[0006] In some implementations, during the step of etching the first copper layer, a second copper layer is also etched to form a second circuit layer, which is connected to the cooling zone.

[0007] In some embodiments, the cooling zone includes a receiving portion and a connecting portion. The receiving portion penetrates the dielectric layer and forms a groove around it. The connecting portion protrudes from the receiving portion in the direction of extension of the first circuit board. The connecting portion is located on the surface of the dielectric layer facing the thermally conductive adhesive, and the thermally conductive adhesive bonds the connecting portion to the electronic component.

[0008] In some embodiments, prior to the lamination step, the manufacturing method further includes: providing an intermediate circuit substrate and a second adhesive layer; and during the lamination step, laminating the first circuit substrate, the first adhesive layer, the intermediate circuit substrate, the second adhesive layer, and the second circuit substrate in a stacked manner.

[0009] This application also provides a method for manufacturing a circuit board assembly, comprising: providing a first circuit substrate including a first circuit layer, the first circuit layer including a cooling region having a groove; providing a first adhesive layer having an opening; providing a second circuit substrate having a through hole; laminating the first circuit substrate, the first adhesive layer and the second circuit substrate in a stacked manner, wherein the cooling region is exposed to the opening and the opening communicates with the through hole; injecting coolant into the groove; bonding thermally conductive adhesive to the periphery of the cooling region; and placing electronic components in the through hole and bonding the electronic components with thermally conductive adhesive to seal the opening.

[0010] A circuit board assembly includes a first circuit substrate, a first adhesive layer, a coolant, a thermally conductive adhesive, and electronic components. The first circuit substrate includes a first circuit layer and a dielectric layer. The first circuit layer includes a cooling region recessed toward the dielectric layer, and the cooling region has a groove. The first adhesive layer is located on one surface of the first circuit substrate and has an opening. The cooling region is accommodated in the opening and exposed to the opening. The coolant is accommodated in the groove. The thermally conductive adhesive surrounds the periphery of the cooling region and is bonded to the first adhesive layer. The electronic components are bonded to the thermally conductive adhesive and the opening is sealed.

[0011] In some embodiments, the cooling zone includes a receiving portion and a connecting portion. The receiving portion penetrates the dielectric layer and forms a groove around it. The connecting portion protrudes from the receiving portion in the direction of extension of the first circuit board. The connecting portion is located on the surface of the dielectric layer facing the thermally conductive adhesive, and the thermally conductive adhesive bonds the connecting portion to the electronic component.

[0012] In some embodiments, the first circuit board further includes a second circuit layer located on the surface of the dielectric layer opposite to the first circuit layer, and the receiving portion is also connected to the second circuit layer.

[0013] In some embodiments, the groove includes a plurality of connecting portions and a plurality of recesses, wherein two adjacent recesses are connected by at least one connecting portion, and one connecting portion connects at least two recesses.

[0014] The method for manufacturing the circuit board assembly provided in this application is highly feasible; by sealing the coolant in the circuit board assembly, and by using the inner walls for containing the coolant as first circuit layers with good thermal conductivity, the heat generated by the electronic components can be quickly transferred away. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of a double-sided copper-clad laminate provided in an embodiment of this application.

[0016] Figure 2 In order to be in Figure 1 A schematic diagram of the cross-section after a blind via is formed on a double-sided copper-clad board.

[0017] Figure 3 In order to be in Figure 2 The diagram shows a cross-sectional view of the cooling zone formed in and around the blind hole.

[0018] Figure 4 A top view of the cooling zone provided for some embodiments.

[0019] Figure 5 This is a cross-sectional schematic diagram of the intermediate circuit board provided in an embodiment of this application.

[0020] Figure 6 This is a cross-sectional schematic diagram of the first adhesive layer and the second adhesive layer provided in the embodiments of this application.

[0021] Figure 7 This is a cross-sectional schematic diagram of an embodiment of the present application, showing the first circuit board, the first adhesive layer, the intermediate circuit board, the second adhesive layer, and the second circuit board arranged in that order.

[0022] Figure 8 For pressing Figure 7 A schematic diagram of the cross-section of the structure shown.

[0023] Figure 9 To Figure 8 The diagram shows a cross-section of the structure after the cover has been opened.

[0024] Figure 10 In order to be in Figure 9 A schematic diagram of the cross-section after coolant is injected into the groove.

[0025] Figure 11 In order to be in Figure 10 A schematic cross-sectional view of the circuit board assembly obtained after connecting electronic components to the cooling zone.

[0026] Explanation of main component symbols

[0027]

[0028] Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of this application; the described embodiments are merely some, not all, of the embodiments described in this application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes all and any combination of one or more of the associated listed items.

[0031] In the various embodiments of this application, for ease of description and not limitation, the term "connection" used in the patent application specification and claims is not limited to physical or mechanical connections, whether direct or indirect. Terms such as "upper," "lower," "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0032] Please see Figures 1 to 11 This application provides a method for manufacturing a circuit board assembly 100, which may include the following steps:

[0033] Step S1: Please refer to Figures 1 to 3 A first circuit board 10 is provided, the first circuit board 10 includes a first circuit layer 13, the first circuit layer 13 includes a cooling region 132, and the cooling region 132 has a groove 134.

[0034] The first circuit board 10 also includes a dielectric layer 11 and a second circuit layer 15 (see [link]). Figure 9 The dielectric layer 11 and the first circuit layer 13 and the second circuit layer 15 can each be one or more layers. In this embodiment, the dielectric layer 11 is one layer, and the first circuit layer 13 and the second circuit layer 15 are located on opposite sides of the dielectric layer 11.

[0035] Please refer to the following: Figure 4 The cooling zone 132 includes a housing portion 1321 and a connecting portion 1323. The housing portion 1321 penetrates the dielectric layer 11 and connects to the second circuit layer 15 (which can be combined). Figure 9The receiving portion 1321 surrounds and forms a groove 134; the connecting portion 1323 protrudes from the receiving portion 1321 in the direction extending along the first circuit substrate 10, and the connecting portion 1323 is located on the surface of the dielectric layer 11 opposite to the second circuit layer 15. The groove 134 includes a plurality of connecting portions 1341 and a plurality of recessed portions 1343, two adjacent recessed portions 1343 are connected through at least one connecting portion 1341, and one connecting portion 1341 connects at least two recessed portions 1343. Viewed along the direction of the first circuit board 10 being stacked, the length of each recess 1343 is greater than the length of the adjacent connecting portion 1341, and the width of each recess 1343 is greater than the width of the adjacent connecting portion 1341. The recess 1343 can facilitate the subsequent containment of a larger volume of coolant 55, and the connecting portion 1341 is used to realize the flow of coolant 55 in different recesses 1343 to increase the speed of heat conduction. In addition, the structural arrangement of multiple recesses 1343 and multiple connecting portions 1341 is also beneficial to increase the connection area between the coolant 55 and the inner wall of the containing portion 1321 to further increase the rate of heat conduction.

[0036] In this embodiment, the method for manufacturing the first circuit board 10 may include the following steps:

[0037] Step S11: Please refer to Figure 1 A double-sided copper-clad laminate 17 is provided, including a dielectric layer 11 and a first copper layer 171 and a second copper layer 173 located on opposite surfaces of the dielectric layer 11.

[0038] Step S12: Please refer to Figure 2 A blind via 175 is formed on the first copper layer 171 and the dielectric layer 11, and the second copper layer 173 is exposed to the blind via 175.

[0039] Blind via 175 penetrates the first copper layer 171 and the dielectric layer 11.

[0040] Step S13: Please refer to Figure 3 A metal layer 177 is formed in the blind via 175, and the metal layer 177 extends to the surface of the first copper layer 171 around the blind via 175; and the first copper layer 171 is fabricated to form the first circuit layer 13.

[0041] Metal layer 177 covers the peripheral wall of blind hole 175 and is connected to the surface of first copper layer 171 located outside blind hole 175; metal layer 177 is also connected to second copper layer 173 exposed to blind hole 175.

[0042] The metal layer 177 is part of the first circuit layer 13. The metal layer 177 located on the periphery of the blind via 175 forms a receiving portion 1321, and the metal layer 177 located outside the blind via 175 forms a connecting portion 1323 with the first copper layer 171.

[0043] During the circuit fabrication process, the second copper layer 173 can also be fabricated to form the second circuit layer 15. In some embodiments, the step of forming the second circuit layer 15 can also be formed in a subsequent process.

[0044] In other embodiments, the method of fabricating the first circuit board 10 is not limited to the steps described above.

[0045] Step S2: Please refer to Figure 5 Provide intermediate circuit board 20.

[0046] In some embodiments, the intermediate circuit substrate 20 may include an intermediate dielectric layer 21, an intermediate circuit layer 23, and a cover layer 25. The intermediate dielectric layer 21 and the intermediate circuit layer 23 are stacked together, and the cover layer 25 covers a portion of the surface of the intermediate circuit layer 23 and / or the intermediate dielectric layer 21. The cover layer 25 is located on the outer surface of the intermediate circuit substrate 20.

[0047] Step S3: Please refer to Figure 6 A first adhesive layer 30 and a second adhesive layer 35 are provided, and an opening 31 is provided on the first adhesive layer 30.

[0048] In some embodiments, the intermediate circuit board 20 and the second adhesive layer 35 may be omitted depending on the actual number of circuit layers required, or other circuit boards and corresponding adhesive layers may be added.

[0049] Step S4: Please refer to Figure 7 A second circuit board 40 is provided.

[0050] The number of dielectric layers 11 and circuit layers in the second circuit board 40 is not limited.

[0051] Step S5: Please refer to the following again. Figure 7 and Figure 8 The first circuit board 10, the first adhesive layer 30, the intermediate circuit board 20, the second adhesive layer 35, and the second circuit board 40 are stacked and pressed together.

[0052] The first adhesive layer 30 bonds the first circuit board 10 and the intermediate circuit board 20. The cooling zone 132 is exposed through the opening 31, and the first adhesive layer 30 surrounds the periphery of the cooling zone 132 and is connected to the cooling zone 132.

[0053] Along the direction in which each circuit board and adhesive layer are stacked, the thickness of the first adhesive layer 30 is greater than the thickness of the connecting portion 1323 protruding from the dielectric layer 11, so that after pressing, the intermediate circuit board 20 and the connecting portion 1323 are spaced apart.

[0054] The first adhesive layer 30 and the second adhesive layer 35 are also provided with grooves 352, which are corresponding to the cover layer 25 of the intermediate circuit board 20. The first adhesive layer 30 and the second adhesive layer 35 respectively cover the peripheral area of ​​the cover layer 25, and the uncovered parts are exposed to the second adhesive layer 35.

[0055] Step S6: Please refer to Figure 9 The cover is opened to form a through hole 50 that penetrates the second circuit substrate 40, the second adhesive layer 35, and the intermediate circuit substrate 20. The through hole 50 is connected to the opening 31 to expose the cooling zone 132.

[0056] Before or after the step of forming the through-hole 50, the fabrication method also includes the step of forming a conductive hole 45, which is used to electrically connect two adjacent circuit boards.

[0057] During the opening process, the second circuit board 40, the second adhesive layer 35, the first adhesive layer 30, and the area of ​​the first circuit board 10 corresponding to the slot 352 are also removed to expose the cover layer 25.

[0058] Step S7: Please refer to Figure 10 Coolant 55 is injected into groove 134.

[0059] Coolant 55 is contained in containment section 1321. The coolant 55 can be made of water, heat transfer oil, ammonia, etc.

[0060] Step S8: Please refer to Figure 11 Thermally conductive adhesive 60 is bonded to the periphery of the cooling zone 132, electronic components 70 are placed in the through holes 50, and the thermally conductive adhesive 60 is used to bond the electronic components 70 to seal the opening 31, thereby obtaining the circuit board assembly 100.

[0061] Thermally conductive adhesive 60 is disposed in a ring on the surface of the cooling zone 132 away from the first circuit board 10 and bonds the connection portion 1323. In some embodiments, thermally conductive adhesive 60 may further be disposed on the surface of the connection portion 1323 located in the middle region.

[0062] Electronic components 70 and cooling zones 132 are bonded to opposite surfaces of thermally conductive adhesive 60. A first adhesive layer 30 is also attached to the side of thermally conductive adhesive 60 to seal coolant 55 in a closed space.

[0063] The electronic component 70, with its pins (not shown), is positioned away from the coolant 55. The electronic component 70 can be electrically connected to the second circuit board 40. The electronic component 70 can be any component that generates heat during operation, including but not limited to chips, resistors, etc.

[0064] In the circuit board assembly 100 manufactured according to the embodiments of this application, the heat generated by the electronic components 70 can be quickly conducted outward through the thermally conductive adhesive 60, the thermally conductive part, and the coolant 55. The circuit board assembly 100 manufactured using the above method first forms a cooling zone 132 for containing the coolant 55 on the first circuit board 10, and then is pressed together with other circuit boards, opened, and filled with coolant 55. This method is suitable for manufacturing both thicker and thinner circuit board assemblies 100, and has high production feasibility.

[0065] The side of the electronic component 70 is connected to the intermediate circuit board 20, and the heat generated by the electronic component 70 can also be conducted outward through the intermediate circuit layer 23 in the intermediate circuit board 20.

[0066] Other embodiments of this application also provide a method for manufacturing a circuit board assembly 100, which differs from the method of the previous embodiment in that: a cover can be first opened on the circuit board and adhesive layer corresponding to the cooling zone 132, and then a pressing process is performed. For example, through holes (not shown) can be formed on the intermediate circuit board 20, the second adhesive layer 35, and the second circuit board 40, respectively, and then pressing is performed, exposing the cooling zone 132 to the through holes. Other steps can be the same as those in the previous embodiment, and will not be repeated here.

[0067] Please refer to it again. Figure 11 This application also provides a circuit board assembly 100, which can be manufactured by the above-described manufacturing method. The circuit board assembly 100 includes a first circuit board 10, a first adhesive layer 30, an intermediate circuit board 20, a second adhesive layer 35, a second circuit board 40, a coolant 55, a thermally conductive adhesive 60, and an electronic component 70. The first circuit board 10, the first adhesive layer 30, the intermediate circuit board 20, the second adhesive layer 35, and the second circuit board 40 are stacked, and the coolant 55 is sealed between the first circuit board 10 and the electronic component 70.

[0068] The first circuit board 10 includes a dielectric layer 11 and a first circuit layer 13 and a second circuit layer 15 located on opposite surfaces of the dielectric layer 11. The first circuit layer 13 includes a cooling region 132, and a groove 134 is formed in the cooling region 132, in which coolant 55 is contained. A first adhesive layer 30 is located on the surface of the first circuit layer 13 facing away from the second circuit layer 15, and an opening 31 is formed in the first adhesive layer 30. The opening 31 surrounds the cooling region 132. Thermally conductive adhesive 60 is annularly formed, and the cooling region 132 faces away from the surface of the first circuit board 10 and bonds electronic components 70 to seal the groove 134.

[0069] The cooling zone 132 includes a receiving portion 1321 and a connecting portion 1323. The receiving portion 1321 penetrates the dielectric layer 11 and connects to the second circuit layer 15, and the receiving portion 1321 forms a groove 134. The connecting portion 1323 protrudes from the receiving portion 1321 along the direction of extension of the first circuit substrate 10, and the connecting portion 1323 is located on the surface of the dielectric layer 11 facing away from the second circuit substrate 40. Please refer to the following: Figure 4 The groove 134 includes multiple connecting portions 1341 and multiple recessed portions 1343. Two adjacent recessed portions 1343 are connected by at least one connecting portion 1341, and one connecting portion 1341 connects at least two recessed portions 1343. The recessed portions 1343 are used to accommodate a larger volume of coolant 55, and the connecting portions 1341 are used to allow the flow of coolant 55 between different recessed portions 1343. The heat generated by the electronic component 70 can be rapidly transferred through the thermally conductive adhesive 60, the cooling zone 132, and the coolant 55, and diffused outward through the second circuit layer 15 connected to the cooling zone 132.

[0070] The side of the electronic component 70 is connected to the first adhesive layer 30 and the intermediate circuit board 20, and can also be further connected to the second adhesive layer 35. The part of the electronic component 70 connected to the intermediate circuit board 20 can also play a role in rapid heat conduction.

[0071] The first circuit board 10 and the intermediate circuit board 20, as well as the intermediate circuit board 20 and the second circuit board 40, can be electrically connected through conductive holes 45. The conductive holes 45 can also further serve as heat conductors.

[0072] The method for manufacturing the circuit board assembly 100 provided in this application is highly feasible. By sealing the coolant 55 in the circuit board assembly 100, and by using the inner wall of the coolant 55 as a first circuit layer 13 with good thermal conductivity, the heat generated by the electronic components 70 can be quickly transferred away.

[0073] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A method for manufacturing a circuit board assembly, characterized in that, include: A first circuit board is provided, including a first circuit layer and a dielectric layer. The first circuit layer includes a cooling region, which is recessed toward the dielectric layer and has a groove. Provide a second circuit board; A first adhesive layer is provided, with an opening; The first circuit board, the first adhesive layer, and the second circuit board are stacked and pressed together, with the cooling zone exposed to the opening; A through-hole is formed that penetrates the second circuit substrate and communicates with the opening; Coolant is injected into the groove, and thermally conductive adhesive is bonded to the periphery of the cooling zone; as well as An electronic component is placed in the through hole, and the thermally conductive adhesive is used to bond the electronic component to seal the opening.

2. The method for manufacturing a circuit board assembly according to claim 1, characterized in that, The steps for fabricating the first circuit board include: A double-sided copper-clad laminate is provided, comprising a dielectric layer and a first copper layer and a second copper layer located on opposite surfaces of the dielectric layer; A blind via is formed on the first copper layer and the dielectric layer, and the second copper layer is exposed on the blind via; A metal layer is formed in the blind via, the metal layer extending to the surface of a first copper layer around the blind via, and the metal layer is also connected to a second copper layer; and The first copper layer is etched to form the first circuit layer.

3. The method for manufacturing a circuit board assembly according to claim 2, characterized in that, In the step of etching the first copper layer, the second copper layer is also etched to form a second circuit layer, which is connected to the cooling zone.

4. The method for manufacturing a circuit board assembly according to any one of claims 1-3, characterized in that, The cooling zone includes a receiving portion and a connecting portion. The receiving portion penetrates the dielectric layer and forms the groove. The connecting portion protrudes from the receiving portion along the direction of the first circuit board. The connecting portion is located on the surface of the dielectric layer facing the thermally conductive adhesive, and the thermally conductive adhesive bonds the connecting portion to the electronic component.

5. The method for manufacturing a circuit board assembly according to claim 1, characterized in that, Prior to the pressing step, the manufacturing method further includes: Provides an intermediate circuit board and a second adhesive layer; During the lamination step, the first circuit board, the first adhesive layer, the intermediate circuit board, the second adhesive layer, and the second circuit board are laminated together.

6. A method for manufacturing a circuit board assembly, characterized in that, include: A first circuit board is provided, including a first circuit layer, the first circuit layer including a cooling region, the cooling region having a groove; A first adhesive layer is provided, with an opening; A second circuit board is provided, which has through holes; The first circuit board, the first adhesive layer, and the second circuit board are laminated together, and the cooling zone is exposed to the opening, which communicates with the through hole. Coolant is injected into the groove, and thermally conductive adhesive is bonded to the periphery of the cooling zone; as well as An electronic component is placed in the through hole, and the thermally conductive adhesive is used to bond the electronic component to seal the opening.

7. A circuit board assembly, characterized in that, include: A first circuit substrate includes a first circuit layer and a dielectric layer. The first circuit layer includes a cooling region that is recessed toward the dielectric layer. The cooling region has a groove. A first adhesive layer is located on one surface of the first circuit board, and the first adhesive layer has an opening, the cooling zone is accommodated in the opening and exposed to the opening; Coolant is contained in the groove; Thermally conductive adhesive, surrounding the periphery of the cooling zone and bonded to the first adhesive layer; and Electronic components, bonded with the thermally conductive adhesive and the opening sealed.

8. The circuit board assembly according to claim 7, characterized in that, The cooling zone includes a receiving portion and a connecting portion. The receiving portion penetrates the dielectric layer and forms the groove. The connecting portion protrudes from the receiving portion along the direction of the first circuit board. The connecting portion is located on the surface of the dielectric layer facing the thermally conductive adhesive, and the thermally conductive adhesive bonds the connecting portion to the electronic component.

9. The circuit board assembly according to claim 8, characterized in that, The first circuit board further includes a second circuit layer, which is located on the surface of the dielectric layer opposite to the first circuit layer, and the receiving portion is also connected to the second circuit layer.

10. The circuit board assembly according to claim 8 or 9, characterized in that, The groove includes multiple connecting portions and multiple recessed portions, two adjacent recessed portions are connected by at least one connecting portion, and one connecting portion connects at least two recessed portions.

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