Circuit board assembly and manufacturing method thereof

Abstract

The invention discloses a circuit board assembly and a manufacturing method thereof. The circuit board assembly comprises a circuit board, an electronic device, a metal piece, a first heat pipe and a second heat pipe. The circuit board comprises a third circuit substrate, a second dielectric layer, a first circuit substrate, a first dielectric layer and a second circuit substrate which are sequentially stacked, the first circuit substrate comprises a first surface, a second surface and a first side face, the first surface and the second surface are oppositely arranged, the first side face is connected with the first surface and the second surface, and the first dielectric layer is in contact with the first surface. The second dielectric layer is in contact with the second surface. The metal piece is embedded in the first circuit substrate, the first heat pipe is embedded in the metal piece and exposed out of the first side face, and the second heat pipe is arranged on the first side face in a protruding mode and connected with the first heat pipe to form a closed loop. Cooling liquid is contained in the first heat pipe and the second heat pipe. The circuit board is provided with an opening, the opening penetrates through the first dielectric layer and the second circuit substrate and exposes the metal piece, and the electronic device is arranged on the metal piece.

Description

Technical Field

[0001] The present invention relates to the field of circuit boards, and in particular to a circuit board assembly capable of rapid heat dissipation and a manufacturing method thereof. Background Art

[0002] With the development of science and technology, more and more components are integrated into electronic devices, making the heat dissipation of electronic devices an important parameter affecting the performance of electronic devices. In existing electronic devices, the heat generated by the components installed on the circuit board is dissipated by using the circuit board itself or the metal reinforcement sheet arranged on the circuit board. However, this heat dissipation method depends on the ambient temperature of the circuit board and has a poor heat dissipation effect. Summary of the invention

[0003] In view of this, the present invention provides a circuit board assembly and a manufacturing method thereof that solves the above technical problems.

[0004] On the one hand, the present application provides a circuit board assembly, including a circuit board, an electronic device, a metal part, a first heat pipe and a second heat pipe. The circuit board includes a third circuit substrate, a second dielectric layer, a first circuit substrate, a first dielectric layer and a second circuit substrate stacked in sequence, the first circuit substrate includes a first surface and a second surface arranged opposite to each other and a first side surface connecting the first surface and the second surface, the first dielectric layer contacts the first surface, and the second dielectric layer contacts the second surface. The metal part is embedded in the first circuit substrate, the first heat pipe is embedded in the metal part and exposed outside the first side surface, the second heat pipe is convexly arranged on the first side surface and connected to the first heat pipe to form a closed loop. The first heat pipe and the second heat pipe contain cooling liquid. The circuit board is provided with an opening, the opening passes through the first dielectric layer and the second circuit substrate and exposes the metal part, and the electronic device is arranged on the metal part.

[0005] Another aspect of the present application is a method for manufacturing a circuit board assembly, comprising the following steps:

[0006] Providing a first circuit substrate, the first circuit substrate comprising a first surface and a second surface arranged opposite to each other;

[0007] forming a through hole penetrating the first surface and the second surface;

[0008] The heat pipe assembly is placed in the through hole, wherein the heat pipe assembly includes a metal piece and a first heat pipe, wherein the first heat pipe includes a body portion and a first interface portion, wherein the body portion is embedded in the metal piece and the first interface portion is protruded on the metal piece;

[0009] A first dielectric layer and a second circuit substrate are sequentially stacked on the first surface, wherein the first dielectric layer has a first opening, the metal piece is exposed in the first opening, the first dielectric layer also covers the first interface portion, and the second circuit substrate covers the first opening;

[0010] forming a second dielectric layer and a third circuit substrate sequentially stacked on the second surface, wherein the second dielectric layer covers the through hole;

[0011] Cut and remove a portion of the second circuit substrate to expose the first opening, and cut and remove a portion of the first circuit substrate, the first dielectric layer, the second circuit substrate, the second dielectric layer, and the third circuit substrate to expose the first interface portion;

[0012] Connecting the second heat pipe and the first interface portion so that the second heat pipe and the first heat pipe form a closed loop, wherein the second heat pipe has a liquid injection hole;

[0013] Injecting coolant into the second heat pipe and the first heat pipe through the injection hole;

[0014] Mount electronic components on metal parts.

[0015] In the circuit board assembly and the manufacturing method thereof provided in the present application, the metal part is embedded in the circuit board and exposed on the surface of the circuit board, the first heat pipe is embedded in the metal part and exposed on the side of the circuit board, the second heat pipe is connected to the first heat pipe and is located outside the circuit board, and the electronic device is arranged on the metal part. The heat generated by the electronic device is absorbed by the coolant in the first heat pipe and the second heat pipe to achieve heat dissipation, and on the other hand, it is also transferred to the outside of the circuit board through the second heat pipe to achieve heat dissipation, thereby improving the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A cross-sectional schematic diagram of a first circuit substrate provided in one embodiment of the present application.

[0017] Figure 2 For Figure 1 The cross-section diagram of the first circuit substrate after a through hole is formed is shown.

[0018] Figure 3 for Figure 2 A top view of the first circuit substrate is shown.

[0019] Figure 4 A schematic structural diagram of a heat pipe assembly provided in one embodiment of the present application.

[0020] Figure 5 For the general Figure 4 The heat pipe assembly shown is placed Figure 2 A cross-sectional schematic diagram of a through hole in the figure, in which a first circuit substrate, a second circuit substrate, a third circuit substrate, a first dielectric layer and a second dielectric layer are stacked.

[0021] Figure 6 For the general Figure 5 The cross-sectional schematic diagram shown is a first circuit substrate, a second substrate, a third substrate, a first dielectric layer and a second dielectric layer after being pressed together.

[0022] Figure 7 For Figure 6 The cross-sectional schematic diagram is shown after the second circuit substrate and the third circuit substrate are formed on the second substrate and the third substrate.

[0023] Figure 8 For the general Figure 7 The schematic cross-sectional view shows the second circuit substrate, the first circuit substrate and the third circuit substrate after being cut and removed.

[0024] Fig. 9 To connect the second heat pipe Figure 8 Schematic cross-sectional view of the first heat pipe after connection.

[0025] Fig.10 A schematic diagram of a second heat pipe provided in one embodiment of the present application.

[0026] Fig.11 For Fig. 9 The cross-sectional schematic diagram is shown after the cooling liquid is injected into the first heat pipe and the second heat pipe.

[0027] Fig.12 A schematic cross-sectional view of a circuit board assembly provided in accordance with an embodiment of the present application.

[0028] Main component symbols

[0029] First circuit substrate 10

[0030] First surface 10a

[0031] Second surface 10b

[0032] First base 11

[0033] The first conductive circuit layer 12

[0034] Via 101

[0035] Main body 101a

[0036] Extension 101b

[0037] Heat pipe assembly 20

[0038] Metal parts 21

[0039] First heat pipe 22

[0040] First surface 21a

[0041] Second surface 21b

[0042] Second side surface 21c

[0043] Body part 221

[0044] First interface portion 222

[0045] The third surface 221a

[0046] The third substrate 601

[0047] The second dielectric layer 50

[0048] The first dielectric layer 30

[0049] Second substrate 401

[0050] First opening 30a

[0051] Second base 41

[0052] First metal layer 42

[0053] The third base 61

[0054] The second metal layer 62

[0055] Conductive hole 110

[0056] The second conductive circuit layer 43

[0057] The third conductive circuit layer 63

[0058] Second circuit substrate 40

[0059] The third circuit substrate 60

[0060] The first original copper layer 431

[0061] First copper plating layer 432

[0062] The second original copper layer 631

[0063] Second copper plating layer 632

[0064] Second opening 43a

[0065] First through groove 43b

[0066] Second through groove 63b

[0067] Solder mask 70

[0068] Solder mask opening 70a

[0069] The second heat pipe 80

[0070] Second interface portion 81

[0071] Liquid injection hole 80a

[0072] Adhesive layer 91

[0073] Coolant 90

[0074] Blocking piece 92

[0075] Electronic devices 210

[0076] Solder pad 210a

[0077] Wire 220

[0078] Thermal conductive adhesive 230

[0079] Circuit board 100

[0080] First side surface 10c

[0081] Opening 120

[0082] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0083] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0084] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0085] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may be combined or replaced with each other.

[0086] An embodiment of the present application provides a method for manufacturing a circuit board assembly, which includes the following steps.

[0087] Step S1, see Figure 1 , providing a first circuit substrate 10, the first circuit substrate 10 includes a first surface 10a and a second surface 10b which are oppositely arranged.

[0088] The first circuit substrate 10 includes a first base layer 11 and a first conductive circuit layer 12 stacked along a first direction Z. In this embodiment, the first circuit substrate 10 includes two first conductive circuit layers 12, the first base layer 11 is sandwiched between the two first conductive circuit layers 12, and the two surfaces of the two first conductive circuit layers 12 facing away from the first base layer 11 are used as a first surface 10a and a second surface 10b. In other embodiments, the number of the first conductive circuit layer 12 is one, and the surface of the first conductive circuit layer 12 facing away from the first base layer 11 is used as the first surface 10a, and the surface of the first base layer 11 facing away from the first conductive circuit layer 12 is used as the second surface 10b.

[0089] In this embodiment, the first base layer 11 is a dielectric layer, and the material of the dielectric layer can be polyimide, epoxy resin, glass fiber prepreg, carbon fiber prepreg, etc. In other embodiments, the first base layer 11 includes a laminated dielectric layer and an inner circuit layer, and the inner circuit layer and the first conductive circuit layer 12 are electrically connected through conductive holes or conductive columns that penetrate the dielectric layer.

[0090] Step S2, see Figure 2 A through hole 101 penetrating the first surface 10a and the second surface 10b is formed on the first circuit substrate 10. The through hole 101 can be formed by mechanical cutting or laser cutting.

[0091] See also Figure 3 The through hole 101 includes a main body 101a and two extensions 101b, and the two extensions 101b extend from the edge of the main body 101a and communicate with the main body 101a. In this embodiment, the two extensions 101b are located on the same side of the main body 101a. In other embodiments, the two extensions 101b are located on different sides of the main body 101a.

[0092] Step S2, see Figure 4, a heat pipe assembly 20 is provided, and the heat pipe assembly 20 includes a metal member 21 and a first heat pipe 22. The metal member 21 includes a first surface 21a and a second surface 21b arranged opposite to each other, and a second side surface 21c connecting the first surface 21a and the second surface 21b. The first heat pipe 22 includes a main body 221 and two first interface portions 222. The main body 221 is embedded in the metal member 21, and includes a third surface 221a exposed to the first surface 21a. In this embodiment, the third surface 221a is flush with the first surface 21a. The main body 221 is generally in the shape of a "W", which includes four straight sections and three bent sections connected alternately. In other embodiments, the number of straight sections and the number of bent sections can be set according to actual needs. The two first interface portions 222 are connected to the two outermost straight sections and protrude from the second side surface 21c. In other embodiments, the third surface 221 a may protrude from or be lower than the first surface 21 a and be exposed outside the first surface 21 a , or the first surface 21 a may cover the third surface 221 a , so that the main body 221 is completely embedded in the metal member 21 .

[0093] Step S3 , placing the heat pipe assembly 20 in the through hole 101 , forming a first dielectric layer and a second circuit substrate sequentially stacked on the first surface 10 a , and forming a second dielectric layer and a third circuit substrate sequentially stacked on the second surface 10 b .

[0094] In some embodiments, step S3 includes the following steps S31-S33.

[0095] Step S31, see Figure 5 and Figure 6 , the heat pipe assembly 20 is placed in the through hole 101, and the third substrate 601, the second dielectric layer 50, the first circuit substrate 10, the first dielectric layer 30 and the second substrate 401 are sequentially stacked and pressed along the first direction Z.

[0096] The metal member 21 is accommodated in the main body 101a, and the two first interface portions 222 are accommodated in the two extension portions 101b. The first surface 21a is flush with the first surface 10a, and the second surface 21b is flush with the second surface 10b. There is a gap between the heat pipe assembly 20 and the edge of the through hole 101, so that the heat pipe assembly 20 can be placed in the through hole 101.

[0097] The first dielectric layer 30 covers the first surface 10a and contacts the first surface 10a. The first dielectric layer 30 has a first opening 30a, the size of which is greater than or equal to the size of the metal member 21 and less than or equal to the size of the main body 101a, so that after the first dielectric layer 30 is pressed onto the first surface 10a, the entire metal member 21 can be exposed through the first opening 30a. After pressing, the entire first surface 21a of the metal member 21 is exposed in the first opening 30a, preventing damage to the heat pipe assembly 20 during subsequent cutting. The first dielectric layer 30 also covers the first interface portion 222.

[0098] The second dielectric layer 50 covers and contacts the second surface 10 b and seals the through hole 101 .

[0099] The first dielectric layer 30 and the second dielectric layer 50 both include polyimide, epoxy resin, glass fiber prepreg, carbon fiber prepreg, etc. During lamination, the first dielectric layer 30 and the second dielectric layer 50 are melted and filled into the gap between the heat pipe assembly 20 and the edge of the through hole 101, and the heat pipe assembly 20 and the first circuit substrate 10 are bonded to improve the stability of the heat pipe assembly 20 in the through hole 101. The second surface 21b and the second side surface 21c of the metal member 21 and the periphery of the first interface portion 222 are surrounded by the first dielectric layer 30 and the second dielectric layer 50 to isolate the heat pipe assembly 20 from the first conductive circuit layer 12.

[0100] The second substrate 401 includes a second base layer 41 and a first metal layer 42 which are stacked. The second base layer 41 covers and contacts the surface of the first dielectric layer 30 which is away from the first surface 10a, and the second base layer 41 also covers the first opening 30a and is not in contact with the heat pipe assembly 20. The third substrate 601 includes a third base layer 61 and a second metal layer 62 which are stacked, and the third base layer 61 covers and contacts the surface of the second dielectric layer 50 which is away from the second surface 10b.

[0101] The second base layer 41 and the third base layer 61 can both be dielectric layers, and the material of the dielectric layer can be polyimide, epoxy resin, glass fiber prepreg, carbon fiber prepreg, etc. The material of the first metal layer 42 and the second metal layer 62 can be copper, gold, silver, etc.

[0102] Step S32, see Figure 6 and Figure 7 , forming a conductive via 110 penetrating the third substrate 601 , the second dielectric layer 50 , the first circuit substrate 10 , the first dielectric layer 30 and the second substrate 401 , the conductive via 110 electrically connecting the first metal layer 42 , the first conductive circuit layer 12 and the second metal layer 62 .

[0103] In some embodiments, the conductive hole 110 may be formed by drilling and electroplating processes in sequence. In other embodiments, a conductive column may be formed that passes through the third substrate 601, the second dielectric layer 50, the first circuit substrate 10, the first dielectric layer 30 and the second substrate 401.

[0104] Step S33, see Figure 6 and Figure 7 A second conductive circuit layer 43 and a third conductive circuit layer 63 are formed on the first metal layer 42 and the second metal layer 62. The second base layer 41 and the second conductive circuit layer 43 constitute the second circuit substrate 40. The third base layer 61 and the third conductive circuit layer 63 constitute the third circuit substrate 60.

[0105] In some embodiments, a dry film is covered on the surface of the first metal layer 42, and then exposed, developed, and electroplated to form the second conductive circuit layer 43; a dry film is covered on the surface of the second metal layer 62, and then exposed, developed, and electroplated to form the third conductive circuit layer 63.

[0106] In this embodiment, the second conductive circuit layer 43 includes a first copper layer 431 and a first copper-plated layer 432 which are stacked, and the third conductive circuit layer 63 includes a second copper layer 631 and a second copper-plated layer 632 which are stacked. The materials of the first copper layer 431 and the second copper layer 631 are both copper foils, and the first copper layer 431 is formed by etching the first metal layer 42, and the second copper layer 631 is formed by etching the second metal layer 62. The first copper-plated layer 432 and the second copper-plated layer 632 are both formed by electroplating.

[0107] The second conductive circuit layer 43 has a second opening 43a, which passes through the first original copper layer 431 and the first copper-plated layer 432 and exposes a portion of the first dielectric layer 30, and the position of the second opening 43a corresponds to the position of the first opening 30a. Along the first direction Z, the orthographic projection of the first opening 30a is located within the orthographic projection of the second opening 43a. In some embodiments, the edge of the second opening 43a is aligned with the edge of the first opening 30a. The second opening 43a is an annular groove. In other embodiments, the second opening 43a can be a through hole.

[0108] The second conductive circuit layer 43 also has a first through slot 43b, which penetrates the first original copper layer 431 and the first copper-plated layer 432 and exposes part of the second base layer 41, and the position of the first through slot 43b corresponds to the position of the two first interface portions 222. In some embodiments, in the first direction Z, the edge of the first through slot 43b is aligned with the edge of the extension portion 101b. The third conductive circuit layer 63 has a second through slot 63b, which penetrates the second original copper layer 631 and the second copper-plated layer 632 and exposes part of the third base layer 61, and the position of the second through slot 63b corresponds to the position of the two first interface portions 222. In some embodiments, in the first direction Z, the edge of the second through slot 63b is aligned with the edge of the first interface portion 222.

[0109] The second opening 43 a , the first through-groove 43 b and the second through-groove 63 b may be formed by mechanical drilling or laser drilling.

[0110] Step S4, see Figure 7 A solder mask 70 is formed on the surface of the second conductive circuit layer 43 and the surface of the third conductive circuit layer 63. The solder mask 70 has a solder mask opening 70a, and the second opening 43a, the first through groove 43b and the second through groove 63b are exposed from the corresponding solder mask openings 70a. Part of the second conductive circuit layer 43 is also exposed from the solder mask opening 70a to connect the electronic device.

[0111] Step S5, see Figure 7 and Figure 8 , a portion of the second circuit substrate 40 is cut and removed to reveal the first opening 30 a , and a portion of the first circuit substrate 10 , the first dielectric layer 30 , the second circuit substrate 40 , the second dielectric layer 50 and the third circuit substrate 60 are cut and removed to reveal the first interface portion 222 .

[0112] In this embodiment, a portion of the second base layer 41 is cut and removed along the edge of the second opening 43a to reveal the first opening 30a; a portion of the second base layer 41 and the first dielectric layer 30 are cut and removed along the edge of the first through groove 43b, and a portion of the third base layer 61 and the second dielectric layer 50 are cut and removed along the edge of the second through groove 63b to reveal the first interface portion 222.

[0113] Step S6, see Fig. 9 , connecting the second heat pipe 80 and the first interface portion 222 so that the second heat pipe 80 and the first heat pipe 22 form a closed loop.

[0114] See also Fig. 9 and Fig.10The second heat pipe 80 includes two second interface parts 81, and the two second interface parts 81 are respectively connected to the two first interface parts 222 to form a closed loop. The second heat pipe 80 has a liquid injection hole 80a for injecting cooling liquid.

[0115] In this embodiment, the second interface portion 81 is inserted into the first interface portion 222 and abuts against the inner wall of the first interface portion 222 to achieve connection.

[0116] In some embodiments, after the second interface portion 81 is inserted into the first interface portion 222 , the contact portions between the second interface portion 81 and the first interface portion 222 are welded together to improve the stability of the connection between the second heat pipe 80 and the first heat pipe 22 .

[0117] See also Fig. 9 , glue is dispensed at the connection between the second interface portion 81 and the first interface portion 222 to form a glue layer 91, and the glue layer 91 adheres the first interface portion 222 to the second interface portion 81. In this embodiment, the glue layer 91 is located between the outer wall of the second interface portion 81 and the outer wall of the first interface portion 222. In other embodiments, the glue layer 91 is located between the inner wall of the first interface portion 222 and the outer wall of the second interface portion 81.

[0118] Step S7, see Fig.11 , coolant 90 is injected into the second heat pipe 80 and the first heat pipe 22 through the injection hole 80a. The coolant 90 is a non-conductive liquid, which can be pure water, ethylene glycol, etc.

[0119] Step S8, see Fig.11 , insert the sealing member 92 into the liquid injection hole 80a to seal the liquid injection hole 80a.

[0120] The blocking member 92 is detachably connected to the injection hole 80a to facilitate adding the coolant 90. In this embodiment, the blocking member 92 is threadedly connected to the injection hole 80a.

[0121] Step S9, see Fig.12 , the electronic device 210 is mounted on the first surface 21 a of the metal member 21 to obtain the circuit board assembly 200 .

[0122] In this embodiment, the electronic device 210 is a chip and has a pad 210a, which is located on a side of the electronic device 210 away from the metal member 21. The pad 210a is electrically connected to the second conductive circuit layer 43 through a wire 220, so that the electronic device 210 and the second conductive circuit layer 43 are electrically connected.

[0123] In this embodiment, the electronic device 210 is bonded to the first surface 21 a of the metal member 21 by means of a thermally conductive adhesive 230 .

[0124] See also Fig.12 In one embodiment of the present application, a circuit board assembly 200 is provided, comprising a circuit board 100, a heat pipe assembly 20, a second heat pipe 80 and an electronic device 210. The circuit board 100 comprises a third circuit substrate 60, a second dielectric layer 50, a first circuit substrate 10, a first dielectric layer 30 and a second circuit substrate 40 stacked in sequence along a first direction Z. The first circuit substrate 10 comprises a first surface 10a and a second surface 10b arranged opposite to each other and a first side surface 10c connecting the first surface 10a and the second surface 10b. The first dielectric layer 30 covers the first surface 10a and contacts the first surface 10a. The second dielectric layer 50 covers the second surface 10b and contacts the second surface 10b.

[0125] The heat pipe assembly 20 includes a metal member 21 and a first heat pipe 22. The metal member 21 is embedded in the first circuit substrate 10, exposed outside the first surface 10a and the second surface 10b, and does not contact the first conductive circuit layer 12. The metal member 21 includes a first surface 21a and a second surface 21b arranged opposite to each other and a second side surface 21c connecting the first surface 21a and the second surface 21b. The second surface 21b and the second side surface 21c are surrounded by a first dielectric layer 30 and a second dielectric layer 50 to isolate the metal member 21 from the first conductive circuit layer 12. The first heat pipe 22 is embedded in the metal member 21 and exposed on the first side surface 10c. The first heat pipe 22 includes a main body 221 and two first interface parts 222. The main body 221 is embedded in the metal member 21 and exposed outside the first surface 21a. The two first interface parts 222 protrude from the second side surface 21c and extend to the first side surface 10c, and do not contact the first conductive circuit layer 12. The periphery of the first interface portion 222 is surrounded by the first dielectric layer 30 and the second dielectric layer 50 to isolate the first interface portion 222 from the first conductive circuit layer 12 .

[0126] The second heat pipe 80 is convexly disposed on the first side surface 10c and connected to the first interface portion 222, so that the second heat pipe 80 is connected to the first heat pipe 22 to form a closed loop. The first heat pipe 22 and the second heat pipe 80 contain cooling liquid 90. The second heat pipe 80 includes two second interface portions 81, and the second interface portion 81 is inserted into the first interface portion 222. The second heat pipe 80 has a liquid injection hole 80a for injecting cooling liquid 90.

[0127] The circuit board assembly 200 further includes an adhesive layer 91 and a blocking member 92. The adhesive layer 91 is disposed on the surfaces of the first interface portion 222 and the second interface portion 81, and bonds the first interface portion 222 and the second interface portion 81. The blocking member 92 is partially accommodated in the injection hole 80a, and blocks the injection hole 80a.

[0128] The circuit board 100 is further provided with an opening 120 . The opening 120 penetrates the first dielectric layer 30 and the second circuit substrate 40 along the first direction Z and exposes the first surface 21 a of the metal member 21 .

[0129] The circuit board 100 further includes a solder mask 70 . The solder mask 70 is disposed on the surfaces of the second circuit substrate 40 and the third circuit substrate 60 that are away from the first circuit substrate 10 .

[0130] The electronic device 210 is disposed on the first surface 21a of the metal member 21 and is accommodated in the opening 120. The electronic device 210 includes a solder pad 210a located on a side of the electronic device 210 away from the metal member 21. The solder pad 210a is electrically connected to the second circuit substrate 40 through a wire 220. A thermal conductive adhesive 230 is sandwiched between the electronic device 210 and the metal member 21.

[0131] The heat generated by the electronic device 210 is transferred to the coolant 90 through the metal part 21 and the first heat pipe 22. The coolant 90 absorbs heat and evaporates, thereby achieving the effects of heat dissipation and temperature reduction. The heat is also transferred to the second heat pipe 80 through the coolant 90 and dissipated to the external environment through the second heat pipe 80, further improving the heat dissipation efficiency.

[0132] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A circuit board assembly, comprising a circuit board and an electronic device, characterized in that: The circuit board includes a third circuit substrate, a second dielectric layer, a first circuit substrate, a first dielectric layer and a second circuit substrate stacked in sequence, the first circuit substrate includes a first surface and a second surface arranged opposite to each other and a first side surface connecting the first surface and the second surface, the first dielectric layer contacts the first surface, and the second dielectric layer contacts the second surface; the circuit board assembly also includes a metal part, a first heat pipe and a second heat pipe, the metal part is embedded in the first circuit substrate, the first heat pipe is embedded in the metal part and exposed outside the first side surface, the second heat pipe is protruded on the first side surface and connected to the first heat pipe to form a closed loop, and the first heat pipe and the second heat pipe contain cooling liquid; the circuit board is provided with an opening, the opening passes through the first dielectric layer and the second circuit substrate and exposes the metal part, and the electronic device is arranged on the metal part.

2. The circuit board assembly according to claim 1, wherein: The first heat pipe includes two first interface parts, and the second heat pipe includes two second interface parts, and the two second interface parts are respectively inserted into the two first interface parts.

3. The circuit board assembly according to claim 2, wherein: The circuit board assembly further includes an adhesive layer, and the adhesive layer bonds the first interface portion and the second interface portion.

4. The circuit board assembly according to claim 1, wherein: The circuit board assembly further includes a blocking member, the second heat pipe has a liquid injection hole, and the blocking member is partially accommodated in the liquid injection hole.

5. The circuit board assembly according to claim 1, wherein: The circuit board assembly also includes a heat-conducting adhesive, which is sandwiched between the electronic device and the metal part.

6. The circuit board assembly according to claim 1, wherein: The metal member includes a first surface exposed at the opening, and the first heat pipe is exposed outside the first surface.

7. The circuit board assembly according to claim 1, wherein: The metal part includes a first surface and a second surface arranged opposite to each other and a second side surface connecting the first surface and the second surface, the first surface is exposed in the opening and outside the first surface, the second surface is exposed outside the second surface, and the second surface and the second side surface are surrounded by the first dielectric layer and the second dielectric layer.

8. The circuit board assembly according to claim 1, wherein: The circuit board assembly further includes a solder resist layer, which is disposed on surfaces of the second circuit substrate and the third circuit substrate facing away from the first circuit substrate.

9. A method for manufacturing a circuit board assembly, characterized in that: The following steps are involved: Providing a first circuit substrate, wherein the first circuit substrate comprises a first surface and a second surface arranged opposite to each other; forming a through hole penetrating the first surface and the second surface; Placing a heat pipe assembly in the through hole, the heat pipe assembly comprising a metal piece and a first heat pipe, the first heat pipe comprising a body portion and a first interface portion, the body portion being embedded in the metal piece, and the first interface portion being convexly disposed on the metal piece; Forming a first dielectric layer and a second circuit substrate sequentially stacked on the first surface, wherein the first dielectric layer has a first opening, the metal member is exposed in the first opening, the first dielectric layer also covers the first interface portion, and the second circuit substrate covers the first opening; forming a second dielectric layer and a third circuit substrate sequentially stacked on the second surface, wherein the second dielectric layer covers the through hole; Cutting and removing a portion of the second circuit substrate to expose the first opening, and cutting and removing a portion of the first circuit substrate, the first dielectric layer, the second circuit substrate, the second dielectric layer, and the third circuit substrate to expose the first interface portion; Connecting a second heat pipe and the first interface portion so that the second heat pipe and the first heat pipe form a closed loop, wherein the second heat pipe has a liquid injection hole; Injecting coolant into the second heat pipe and the first heat pipe through the injection hole; The electronic device is mounted on the metal member.

10. The method for manufacturing a circuit board assembly according to claim 9, wherein: The second heat pipe includes a second interface portion, and the second interface portion is inserted into the first interface portion.

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