Manufacturing method of circuit board assembly, circuit board assembly and terminal device

Abstract

A manufacturing method of a circuit board assembly comprises the steps that a first circuit substrate is provided and comprises a first circuit layer, a first adhesive layer and first conductive paste, and the first conductive paste penetrates through the first adhesive layer and is connected with the first circuit layer; a second circuit substrate is provided and comprises a second circuit layer, a second adhesive layer and second conductive paste, and the second conductive paste penetrates through the second adhesive layer and is connected with the second circuit layer; connecting the first circuit substrate with the second circuit substrate, and connecting the first conductive paste with the second conductive paste; covering the surface, deviating from the second circuit substrate, of the first circuit substrate with a third circuit substrate; a conduction column penetrating through the third circuit substrate is formed, the conduction column is connected with the first circuit layer, and the projection of each first conductive paste and the projection of the corresponding second conductive paste on the third circuit substrate fall into the corresponding conduction column; covering the surface of the third circuit substrate with a heat-conducting polymer; and connecting an electronic element on the second circuit layer. The invention further provides a circuit board assembly and a terminal device.

Description

Technical Field

[0001] The present application relates to the field of heat dissipation technology, and in particular to a method for manufacturing a circuit board assembly, a circuit board assembly, and a terminal device. Background Art

[0002] Electronic components are usually connected to the circuit board. The electronic components will generate heat during operation. When the density of the electronic components is high, the heat generated is too much and difficult to dissipate, the working state of the electronic components will be affected. Summary of the invention

[0003] A method for manufacturing a circuit board assembly includes providing a first circuit substrate, including a first circuit layer, a first glue layer and a first conductive paste, wherein the first glue layer is located on the surface of the first circuit layer, and the first conductive paste penetrates the first glue layer and connects the first circuit layer; providing a second circuit substrate, including a second circuit layer, a second glue layer and a second conductive paste, wherein the second glue layer is located on the surface of the second circuit layer, and the second conductive paste penetrates the second glue layer and connects the second circuit layer; connecting the first circuit substrate with the second circuit substrate, connecting the first glue layer with the second glue layer, and connecting the first conductive paste with the second conductive paste; covering a third circuit substrate on the surface of the first circuit substrate away from the second circuit substrate; forming a conductive column penetrating the third circuit substrate, wherein the conductive column is connected to the first circuit layer, and the projections of each first conductive paste and the corresponding second conductive paste on the third circuit substrate fall into the corresponding conductive column; covering the surface of the third circuit substrate with a thermal conductive polymer; and connecting electronic components on the second circuit layer.

[0004] In some embodiments of the present application, the manufacturing method further includes: performing surface treatment on the thermally conductive polymer to increase the roughness of the thermally conductive polymer.

[0005] In some embodiments of the present application, the step of connecting electronic components on the second circuit layer includes: covering the surface of the second circuit substrate with a solder mask, the solder mask covering the second circuit layer; forming a receiving groove penetrating the solder mask to expose the second circuit layer; filling the receiving groove with a third conductive paste; and connecting the electronic components on the third conductive paste.

[0006] In some embodiments of the present application, along the direction in which the first circuit substrate and the second circuit substrate are stacked, the cross-section of the receiving groove is an arc surface.

[0007] In some embodiments of the present application, the step of forming a first circuit substrate includes: performing circuit production on a double-sided copper clad laminate, the double-sided copper clad laminate includes a first dielectric layer and a first copper layer located on two opposite surfaces of the first dielectric layer, and performing circuit production on the first copper layer to form a first circuit layer; covering the surface of one of the first circuit layers with a first adhesive layer, the first adhesive layer also covering the surface of the first dielectric layer exposed to the first circuit layer; laser cutting to form a plurality of first blind holes penetrating the first adhesive layer, one of the first circuit layers, and the first dielectric layer, with another first circuit layer exposed to the first blind holes; and filling each first blind hole with a first conductive paste to form a first circuit substrate.

[0008] In some embodiments of the present application, the step of forming a conductive column passing through the third circuit substrate includes: forming a second blind hole passing through the third circuit substrate, the projection of each first conductive paste and the corresponding second conductive paste on the third circuit substrate falling into the corresponding second blind hole; and forming a conductive column in the second blind hole.

[0009] A circuit board assembly comprises a circuit board, a third conductive paste and an electronic component.

[0010] The circuit board includes a first circuit substrate, a second circuit substrate, a third circuit substrate, a conductive column and a heat dissipation polymer. The first circuit substrate includes a first circuit layer, a first adhesive layer and a first conductive paste, the first adhesive layer is located on the surface of the first circuit layer, the first conductive paste penetrates the first adhesive layer and connects the first circuit layer; the second circuit substrate includes a second circuit layer, a second adhesive layer and a second conductive paste, the second adhesive layer is located on the surface of the second circuit layer, the second conductive paste penetrates the second adhesive layer and connects the second circuit layer, the second adhesive layer is connected to the first adhesive layer, the second conductive paste is connected to the first conductive paste, a receiving groove is provided on the second circuit substrate, and the second circuit layer is exposed to the receiving groove; the third circuit substrate is located on the surface of the first circuit substrate away from the second circuit substrate; the conductive column penetrates the third circuit substrate and is connected to the first circuit substrate, and the projections of each first conductive paste and the corresponding second conductive paste on the third circuit substrate fall into the corresponding conductive column; the heat conductive polymer covers the surface of the third circuit substrate. The third conductive paste is received in the receiving groove and connected to the second circuit layer; the electronic component is connected to the third conductive paste.

[0011] In some embodiments of the present application, a plurality of grooves are formed on a surface of the thermally conductive polymer that faces away from the third circuit substrate.

[0012] In some embodiments of the present application, along the direction in which the first circuit substrate and the second circuit substrate are stacked, the cross-section of the receiving groove is an arc surface.

[0013] A terminal device comprises the circuit board assembly claimed in claim 1.

[0014] The manufacturing method of the circuit board assembly provided in the embodiment of the present application forms a first conductive paste and a second conductive paste by plugging holes. The density of the formed first conductive paste and the second conductive paste is relatively high, which is conducive to connecting more electronic components; a wider conductive column is formed to improve the thermal conductivity rate; and covering the surface of the third circuit substrate with a thermally conductive polymer can increase the heat dissipation rate of the circuit board assembly to quickly dissipate the heat generated by the electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A cross-sectional schematic diagram of a first adhesive layer covering a first circuit layer provided in an embodiment of the present application.

[0016] Figure 2 For Figure 1 A schematic cross-sectional view of the structure shown after a first blind hole is formed.

[0017] Figure 3 For Figure 2 The cross-sectional schematic diagram of the first circuit substrate obtained after the blind hole is filled with the first conductive paste is shown.

[0018] Figure 4 To connect the second circuit substrate Figure 3 The cross-sectional schematic diagram of the first circuit substrate after connection is shown.

[0019] Figure 5 It is a cross-sectional schematic diagram after the third circuit substrate is covered on the surface of the first circuit substrate and a second blind hole penetrating the third circuit substrate is formed.

[0020] Figure 6 For Figure 5 The schematic cross-sectional view of the second blind hole after the conductive pillar is formed is shown.

[0021] Figure 7 For Figure 6 The schematic cross-sectional view of the surface of the third circuit substrate after being covered with a thermally conductive polymer is shown.

[0022] Figure 8 For Figure 7 The cross-sectional schematic diagram is shown after the surface of the first circuit substrate is covered with a solder mask layer and a receiving groove is formed on the solder mask layer.

[0023] Fig. 9 For Figure 8 The schematic cross-sectional view of the circuit board assembly obtained after forming the third conductive paste in the receiving groove and connecting the electronic components on the third conductive paste is shown.

[0024] Main component symbols

[0025]

[0026] DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth to facilitate a full understanding of the present application, and the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0028] 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 in the specification of this article are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes all and any combination of one or more related listed items.

[0029] In the embodiments of the present application, for the convenience of description and not to limit the present application, the term "connection" used in the patent application specification and claims of the present application is not limited to physical or mechanical connection, whether direct or indirect. "Up", "down", "above", "below", "left", "right", etc. are only used to indicate relative position relationship. When the absolute position of the described object changes, the relative position relationship also changes accordingly.

[0030] See also Figures 1 to 9 The present invention provides a method for manufacturing a circuit board assembly 100, which may include the following steps:

[0031] Step S1: Please refer to Figures 1 to 3 , providing a first circuit substrate 10, including a first circuit layer 13, a first adhesive layer 15 and a first conductive paste 17, the first adhesive layer 15 is located on the surface of the first circuit layer 13, and the first conductive paste 17 penetrates the first adhesive layer 15 and connects the first circuit layer 13.

[0032] In this embodiment, the first circuit substrate 10 also includes a first dielectric layer 11, the number of first circuit layers 13 is two, the two first circuit layers 13 are located on two opposite surfaces of the first dielectric layer 11, the first glue layer 15 is located on the surface of one of the first circuit layers 13, and the first conductive paste 17 penetrates the first glue layer 15, one of the first circuit layers 13 and the first dielectric layer 11, thereby being connected to the other first circuit layer 13 exposed to the first dielectric layer 11.

[0033] In other embodiments, the number of the first dielectric layer 11 is not limited to one layer, and the number of the first circuit layer 13 is not limited to two layers.

[0034] See also Figures 1 to 3 The method for manufacturing the first circuit substrate 10 may include the following steps:

[0035] Step S11: Please refer to Figure 1 , circuits are fabricated on a double-sided copper clad laminate (not shown).

[0036] The double-sided copper clad laminate includes a first dielectric layer 11 and first copper layers (not shown) located on two opposite surfaces of the first dielectric layer 11 . The two first copper layers are processed to form first circuit layers 13 .

[0037] Step S12: Please refer again Figure 1 , the surface of one of the first circuit layers 13 is covered with the first adhesive layer 15 , and the first adhesive layer 15 also covers the surface of the first dielectric layer 11 exposed on the first circuit layer 13 .

[0038] Step S13: Please refer to Figure 2 , laser cutting is performed to form a plurality of first blind holes 19 penetrating the first glue layer 15 , one of the first circuit layers 13 and the first dielectric layer 11 , and another first circuit layer 13 is exposed to the first blind holes 19 .

[0039] Step S14: Please refer to Figure 3 , a first conductive paste 17 is filled in each first blind hole 19 to form a first circuit substrate 10 .

[0040] The first conductive paste 17 is connected to the first circuit layer 13 exposed to the first blind hole 19 , and the surface of the first conductive paste 17 is exposed to the first adhesive layer 15 , so as to be used for subsequent electrical connection.

[0041] By using laser cutting to form the first blind holes 19, first blind holes 19 with smaller spacing can be formed, and the size of each first blind hole 19 can be precisely controlled. After the first blind holes 19 are filled with the first conductive paste 17, the spacing between adjacent first conductive pastes 17 can be reduced, which is conducive to forming a higher density of first conductive pastes 17.

[0042] Step S2: Please refer to Figure 4 , providing a second circuit substrate 20, including a second circuit layer 23, a second adhesive layer 25 and a second conductive paste 27, the second adhesive layer 25 is located on the surface of the second circuit layer 23, and the second conductive paste 27 penetrates the second adhesive layer 25 and connects the second circuit layer 23.

[0043] In this embodiment, the second circuit substrate 20 also includes a second dielectric layer 21, the second circuit layer 23 has two layers, the two second circuit layers 23 are located on two opposite surfaces of the second dielectric layer 21, the second glue layer 25 is located on the surface of one of the second circuit layers 23, and the second conductive paste 27 penetrates the second glue layer 25, one of the second circuit layers 23 and the second dielectric layer 21, thereby being connected to the other second circuit layer 23 exposed to the second dielectric layer 21.

[0044] In other embodiments, the number of second dielectric layers 21 is not limited to one layer, and the number of second circuit layers 23 is not limited to two layers. The manufacturing method of the second circuit substrate 20 can be the same as the manufacturing method of the first circuit substrate 10, which will not be repeated here.

[0045] Step S3: Please refer again Figure 4 , the first circuit substrate 10 is connected to the second circuit substrate 20 , the first adhesive layer 15 is connected to the second adhesive layer 25 , and the first conductive paste 17 is connected to the second conductive paste 27 .

[0046] The first circuit substrate 10 and the second circuit substrate 20 are connected in such a way that the first adhesive layer 15 and the second adhesive layer 25 face inwards and the first circuit layer 13 and the second circuit layer 23 face outwards. Each first conductive paste 17 is connected to a corresponding second conductive paste 27 .

[0047] Step S4: Please refer to Figure 5 The third circuit substrate 30 is covered on the surface of the first circuit substrate 10 facing away from the second circuit substrate 20 .

[0048] In this embodiment, the third circuit substrate 30 is made of a single-sided copper-clad laminate (not shown). The single-sided copper-clad laminate includes a third dielectric layer 31 and a third copper layer (not shown) located on the surface of the third dielectric layer 31. The third copper layer is formed into a third circuit layer 33 after circuit production. The third dielectric layer 31 covers the surface of the first circuit substrate 10, and the third circuit layer 33 is located on the surface of the third dielectric layer 31 away from the first circuit substrate 10.

[0049] Step S5: Please refer to Figure 5 and Figure 6 , forming a conducting column 37 penetrating the third circuit substrate 30 , and the conducting column 37 is connected to the first circuit layer 13 .

[0050] A second blind hole 35 is formed on the third circuit substrate 30. The second blind hole 35 penetrates the third copper layer and the third dielectric layer 31. The first circuit layer 13 is exposed in the second blind hole 35. The projection of each first conductive paste 17 and the corresponding second conductive paste 27 on the third circuit substrate 30 falls into the corresponding second blind hole 35. A conductive column 37 can be formed in the second blind hole 35 by electroplating. The conductive column 37 is filled in the second blind hole 35 and connected to the first circuit layer 13. Then, the projection of each first conductive paste 17 and the corresponding second conductive paste 27 on the third circuit substrate 30 falls into the corresponding conductive column 37, that is, the width A of the conductive column 37 is greater than the maximum width B of the first conductive paste 17 and the second conductive paste 27, and each conductive column 37 is arranged corresponding to the position of the first conductive paste 17 and the second conductive paste 27.

[0051] The second blind via 35 may also penetrate the first circuit layer 13 , and the conductive pillar 37 may also be connected to the first conductive paste 17 .

[0052] In the process of forming the second blind hole 35 , the width of the drilled hole can be adjusted to form the second blind hole 35 with a larger hole diameter, and the conductive pillar 37 formed in the second blind hole 35 has a larger diameter.

[0053] Step S6: Please refer to Figure 7 , the surface of the third circuit substrate 30 is covered with a thermally conductive polymer 40 .

[0054] The thermal conductivity of the thermally conductive polymer 40 is relatively high, including but not limited to polyacetylene, polyaniline, polypyrrole, etc. The thermally conductive polymer 40 can play a role in rapid heat dissipation. The thermal conductivity of the thermally conductive polymer 40 is greater than the thermal conductivity of the dielectric layer (i.e., the first dielectric layer 11, the second dielectric layer 21, and the third dielectric layer 31).

[0055] In some embodiments, the manufacturing method may further include: performing surface treatment on the thermally conductive polymer 40 to increase the roughness of the thermally conductive polymer 40. In this embodiment, a plurality of grooves 41 are formed on the surface of the thermally conductive polymer 40, which is equivalent to reducing the thickness of the thermally conductive polymer 40 on the one hand, and increasing the heat dissipation area of ​​the thermally conductive polymer 40 on the other hand, which can accelerate the heat dissipation.

[0056] Step S7: Please refer to Figure 8 and Fig. 9 , the electronic component 70 is connected to the second circuit layer 23 .

[0057] Step S71: Please refer to Figure 8 The second circuit substrate 20 is covered with a solder mask 50 , and the solder mask 50 also covers the second circuit layer 23 , thereby forming a circuit board 60 .

[0058] Before the step of covering the solder mask 50 , the manufacturing method further includes performing a gold treatment on the second circuit layer 23 to form a gold layer 29 on the surface of the second circuit layer 23 .

[0059] Step S72: Please refer to Figure 8 , forming a plurality of receiving grooves 51 penetrating the solder mask layer 50 to expose the second circuit layer 23 .

[0060] Step S73: Please refer to Fig. 9 , filling the receiving groove 51 with a third conductive paste 53 .

[0061] Along the direction in which the first circuit substrate 10 and the second circuit substrate 20 are stacked, the cross-section of each receiving groove 51 is in an arc shape. Since the third conductive paste 53 is added to the receiving groove 51, before curing, due to the existence of surface tension, the surface of the third conductive paste 53 is an arc surface. The arc-shaped receiving groove 51 can better fit the third conductive paste 53, and can improve the connection reliability between the third conductive paste 53 and the second circuit substrate 20.

[0062] Step S74: Please refer again Fig. 9 , an electronic component 70 is connected to the third conductive paste 53 .

[0063] The electronic component 70 can be an LED, thereby forming a high-density light-emitting crystal grain. The heat generated by the high-density LED can be dissipated through the second circuit layer 23, the second conductive paste 27, the first conductive paste 17, the conductive pillar 37 and the thermal conductive polymer 40 in sequence. The conductive pillar 37 is wide, which can increase the heat transfer efficiency; each conductive pillar 37 and the first conductive paste 17 and the second conductive paste 27 are arranged in a corresponding position, which can shorten the heat transfer path and improve the efficiency of heat transfer; the thermal conductive polymer 40 located on the outer surface can improve the heat dissipation efficiency.

[0064] Please refer again Fig. 9 The embodiment of the present application further provides a circuit board assembly 100 , which includes a circuit board 60 , a third conductive paste 53 and an electronic component 70 , wherein the third conductive paste 53 connects the circuit board 60 and the electronic component 70 .

[0065] The circuit board assembly 100 may include a first circuit substrate 10 , a second circuit substrate 20 and a third circuit substrate 30 , wherein the second circuit substrate 20 and the third circuit substrate 30 are located on opposite sides of the first circuit substrate 10 .

[0066] The first circuit substrate 10 may include a first dielectric layer 11, a first circuit layer 13, a first glue layer 15, and a first conductive paste 17. The first circuit layer 13 is located on two opposite surfaces of the first dielectric layer 11. The first glue layer 15 is located on a surface of one of the first circuit layers 13 away from the first dielectric layer 11, and the first conductive paste 17 penetrates the first glue layer 15, one of the first circuit layers 13, and the first dielectric layer 11 and connects the first circuit layer 13. In other embodiments, when the number of layers of the first dielectric layer 11 is not limited to one layer and the number of layers of the first circuit layer 13 is not limited to two layers, the structure of the first circuit substrate 10 may be adaptively changed.

[0067] The second circuit substrate 20 may include a second dielectric layer 21, a second circuit layer 23, a second adhesive layer 25, and a second conductive paste 27. The second circuit layer 23 is located on two opposite surfaces of the second dielectric layer 21. The second adhesive layer 25 is located on the surface of one of the second circuit layers 23 away from the second dielectric layer 21, and the second conductive paste 27 penetrates the second adhesive layer 25, one of the second circuit layers 23, and the second dielectric layer 21 and connects the second circuit layer 23. The second adhesive layer 25 is connected to the first adhesive layer 15, and the second conductive paste 27 is connected to the first conductive paste 17. A receiving groove 51 is provided on the second circuit substrate 20, and the second circuit layer 23 is exposed in the receiving groove 51. The third conductive paste 53 is received in the receiving groove 51 and connected to the second circuit layer 23. The electronic component 70 is connected to the third conductive paste 53, so that the electronic component 70 is electrically connected to the circuit board 60.

[0068] In some embodiments, along the direction in which the first circuit substrate 10 and the second circuit substrate 20 are stacked, the cross section of the receiving groove 51 is an arc surface.

[0069] The third circuit substrate 30 is located on the surface of the first circuit substrate 10 away from the second circuit substrate 20. The third circuit substrate 30 includes a third dielectric layer 31 and a third circuit layer 33. The third dielectric layer 31 covers the surface of the first circuit substrate 10, and the third circuit layer 33 is located on the surface of the third dielectric layer 31 away from the first circuit substrate 10. A second blind hole 35 is opened on the third circuit substrate 30, and the first circuit layer 13 is exposed in the second blind hole 35. The conductive column 37 is accommodated in the second blind hole 35 and connected to the third circuit layer 33, so that the conductive column 37 passes through the third circuit substrate 30 and is connected to the first circuit substrate 10. The projection of each first conductive paste 17 and the corresponding second conductive paste 27 on the third circuit substrate 30 falls into the corresponding conductive column 37, that is, the width A of the conductive column 37 is greater than the maximum width B of the first conductive paste 17 and the second conductive paste 27.

[0070] In some embodiments, the conductive pillar 37 also penetrates the first wiring layer 13 and is connected to the first conductive paste 17 .

[0071] The circuit board 60 may further include a thermally conductive polymer 40 . The thermally conductive polymer 40 covers a surface of the third circuit substrate 30 facing away from the first circuit substrate 10 . The thermally conductive polymer 40 also covers the conductive pillars 37 .

[0072] A plurality of grooves 41 are formed on the surface of the thermally conductive polymer 40 facing away from the third circuit substrate 30 . The grooves 41 are used to increase the heat dissipation area of ​​the thermally conductive polymer 40 .

[0073] The circuit board 60 further includes a solder mask layer 50 , which covers the second circuit layer 23 , and the third conductive paste 53 also penetrates the solder mask layer 50 .

[0074] The present application also provides a terminal device (not shown), the terminal device includes a circuit board assembly 100, and the terminal device includes but is not limited to a display screen, a wearable electronic product, an XR virtual camera, etc.

[0075] The manufacturing method of the circuit board assembly 100 provided in the embodiment of the present application forms the first conductive paste 17 and the second conductive paste 27 by plugging holes. The density of the formed first conductive paste 17 and the second conductive paste 27 is relatively high, which is conducive to connecting more electronic components 70; a wider conductive column 37 is formed to improve the thermal conductivity rate; covering the surface of the third circuit substrate 30 with a thermally conductive polymer 40 can increase the heat dissipation rate of the circuit board assembly 100, so as to quickly dissipate the heat generated by the electronic components 70.

[0076] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for manufacturing a circuit board assembly, characterized in that: include: Providing a first circuit substrate, comprising a first circuit layer, a first adhesive layer and a first conductive paste, wherein the first adhesive layer is located on a surface of the first circuit layer, and the first conductive paste penetrates the first adhesive layer and connects the first circuit layer; Providing a second circuit substrate, comprising a second circuit layer, a second adhesive layer and a second conductive paste, wherein the second adhesive layer is located on the surface of the second circuit layer, and the second conductive paste penetrates the second adhesive layer and connects the second circuit layer; Connecting the first circuit substrate to the second circuit substrate, connecting the first adhesive layer to the second adhesive layer, and connecting the first conductive paste to the second conductive paste; Covering a third circuit substrate on a surface of the first circuit substrate facing away from the second circuit substrate; forming a conducting column penetrating the third circuit substrate, the conducting column being connected to the first circuit layer, and the projection of each of the first conductive paste and the corresponding second conductive paste on the third circuit substrate falling into the corresponding conducting column; Covering a thermally conductive polymer on the surface of the third circuit substrate; as well as Electronic components are connected on the second circuit layer.

2. The method for manufacturing a circuit board assembly according to claim 1, characterized in that: The production method further comprises: The thermally conductive polymer is surface treated to increase the roughness of the thermally conductive polymer.

3. The method for manufacturing a circuit board assembly according to claim 1, characterized in that: The step of connecting the electronic components on the second circuit layer comprises: Covering a solder mask on the surface of the second circuit substrate, wherein the solder mask covers the second circuit layer; forming a receiving groove penetrating the solder mask layer to expose the second circuit layer; Filling the receiving groove with a third conductive paste; and The electronic component is connected to the third conductive paste.

4. The method for manufacturing a circuit board assembly according to claim 3, characterized in that: Along the direction in which the first circuit substrate and the second circuit substrate are stacked, the cross section of the receiving groove is an arc surface.

5. The method for manufacturing a circuit board assembly according to claim 1, characterized in that: The step of forming the first circuit substrate comprises: Fabricating circuits on a double-sided copper-clad laminate, wherein the double-sided copper-clad laminate comprises a first dielectric layer and first copper layers located on two opposite surfaces of the first dielectric layer, and fabricating circuits on the first copper layer to form the first circuit layer; The first adhesive layer is covered on the surface of one of the first circuit layers, and the first adhesive layer also covers the surface of the first dielectric layer exposed on the first circuit layer; Laser cutting to form a plurality of first blind holes penetrating the first glue layer, one of the first circuit layers and the first dielectric layer, with another first circuit layer exposed to the first blind holes; and A first conductive paste is filled in each of the first blind holes to form the first circuit substrate.

6. The method for manufacturing a circuit board assembly according to claim 1, characterized in that: The step of forming the conducting column penetrating the third circuit substrate comprises: forming a second blind hole penetrating through the third circuit substrate, wherein the projections of each of the first conductive paste and the corresponding second conductive paste on the third circuit substrate fall into the corresponding second blind hole; and The conducting pillar is formed in the second blind hole.

7. A circuit board assembly, characterized in that: include: Circuit board, including: A first circuit substrate comprises a first circuit layer, a first adhesive layer and a first conductive paste, wherein the first adhesive layer is located on a surface of the first circuit layer, and the first conductive paste penetrates the first adhesive layer and connects the first circuit layer; a second circuit substrate, comprising a second circuit layer, a second adhesive layer and a second conductive paste, wherein the second adhesive layer is located on a surface of the second circuit layer, the second conductive paste penetrates the second adhesive layer and connects the second circuit layer, the second adhesive layer is connected to the first adhesive layer, the second conductive paste is connected to the first conductive paste, a receiving groove is provided on the second circuit substrate, and the second circuit layer is exposed in the receiving groove; a third circuit substrate, located on a surface of the first circuit substrate facing away from the second circuit substrate; A conductive column, which passes through the third circuit substrate and is connected to the first circuit substrate, wherein the projections of each of the first conductive paste and the corresponding second conductive paste on the third circuit substrate fall into the corresponding conductive column; A thermally conductive polymer covering the surface of the third circuit substrate; A third conductive paste is contained in the containing groove and connected to the second circuit layer; and The electronic component is connected to the third conductive paste.

8. The circuit board assembly according to claim 7, characterized in that: A plurality of grooves are formed on a surface of the thermal conductive polymer facing away from the third circuit substrate.

9. The circuit board assembly according to claim 7, characterized in that: Along the direction in which the first circuit substrate and the second circuit substrate are stacked, the cross section of the receiving groove is an arc surface.

10. A terminal device, comprising the circuit board assembly according to any one of claims 7 to 9.

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