Circuit board assembly and method of making the same

Abstract

A circuit board assembly includes a circuit substrate and a metal plate, wherein the circuit substrate includes a dielectric layer, a circuit layer, at least one conductive column and two solder mask layers, wherein the conductive column is buried in the dielectric layer and protrudes from the surface of the circuit layer, and the dielectric layer, the circuit layer and the conductive column are located between the two solder mask layers; a through groove penetrates the circuit substrate along the stacking direction of the two solder mask layers, and the conductive column is at least partially exposed from the inner wall of the through groove; the metal plate includes a body stacked and attached to one side of the solder mask layer away from the other solder mask layer, and a protruding portion protruding from one side of the body and accommodated in the through groove, wherein the protruding portion is electrically connected to the conductive column through a conductive material, which is beneficial to prolonging the service life of the circuit board assembly. The present application also provides a method for manufacturing a circuit board assembly.

Description

Technical Field

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

[0002] In the field of circuit board design and manufacturing, there are more and more ways to ground the steel sheet. The current process usually provides a copper-exposed area on the solder mask to expose the connection pad (Pad) for electrical connection with the steel sheet. However, when the spacing between the two connection pads is small, the adhesion area of ​​the solder mask corresponding to the part between the two connection pads is small, and the risk of falling off is very high. Furthermore, the thickness of the solder mask corresponding to the corner of the connection pad is thin, which increases the risk of anodic leakage (CAF) of the glass fiber yarn. Summary of the invention

[0003] In view of this, it is necessary to provide a method for manufacturing a circuit board assembly that solves the above problems.

[0004] A circuit board assembly is also provided to solve the above problem.

[0005] A method for manufacturing a circuit board assembly comprises the following steps:

[0006] A circuit substrate is provided, comprising a dielectric layer, a circuit layer, at least one conductive column and two solder mask layers, wherein the conductive column is embedded in the dielectric layer and protrudes from the surface of the circuit layer, and the dielectric layer, the circuit layer and the conductive column are located between the two solder mask layers;

[0007] A through slot is provided along the stacking direction of the two solder resist layers and penetrates the circuit substrate, and each of the conductive pillars is at least partially exposed from the inner wall of the through slot;

[0008] A metal plate is provided, comprising a main body and a protruding portion protruding from one side of the main body;

[0009] The metal plate is stacked and bonded to a circuit substrate provided with the through slot, wherein the body is bonded to one of the solder resist layers, and the protruding portion is received in the through slot and electrically connected to the conductive column via a conductive material.

[0010] A circuit board assembly comprises a circuit substrate and a metal plate, wherein the circuit substrate comprises a dielectric layer, a circuit layer, at least one conductive column and two solder mask layers, wherein the conductive column is buried in the dielectric layer and protrudes from the surface of the circuit layer, and the dielectric layer, the circuit layer and the conductive column are located between the two solder mask layers; a through groove penetrates the circuit substrate along the stacking direction of the two solder mask layers, and the conductive column is at least partially exposed from the inner wall of the through groove; the metal plate comprises a main body stacked and attached to one side of the solder mask layer away from the other solder mask layer, and a protruding portion protruding from one side of the main body and accommodated in the through groove, wherein the protruding portion is electrically connected to the conductive column through a conductive material.

[0011] In the above-mentioned circuit board assembly and its manufacturing method of the present application, the metal plate is stacked and attached to the circuit substrate, so that the metal plate can quickly conduct the heat transmitted from the circuit substrate, which is beneficial to improving the heat dissipation effect of the circuit substrate. At the same time, the circuit substrate is electrically connected to the protruding portion through the conductive column to achieve grounding from the inner wall of the through groove, and there is no need to open an opening on the solder mask to expose the electrical connection area to be electrically connected to the metal plate, which reduces the risk of the solder mask falling off due to the small attachment area, and also reduces the CAF risk, which is beneficial to extend the service life of the circuit board assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic cross-sectional view of a circuit board according to one embodiment of the present invention.

[0013] Figure 2 is Figure 1 The schematic cross-sectional view of a through groove formed on a circuit substrate is shown.

[0014] Figure 3 It is a schematic cross-sectional view of a metal plate according to one embodiment of the present invention.

[0015] Figure 4 Yes Figure 2 Circuit board and Figure 3 Schematic cross-sectional view of metal plates stacked, bonded and electrically connected.

[0016] Figure 5 is Figure 4 Schematic diagram of a cross section of electronic components mounted on a metal plate.

[0017] Figure 6 It is a schematic cross-sectional view of a metal plate according to one embodiment of the present invention.

[0018] Figure 7 Yes Figure 6 Metal plates and Figure 2 Schematic cross-sectional view of circuit substrate lamination bonding.

[0019] Figure 8 Yes Figure 7 A schematic cross-sectional view of the electrical connection between the metal plate and the circuit substrate.

[0020] Fig. 9 It is a cross-sectional schematic diagram of a circuit board assembly according to one embodiment of the present invention.

[0021] Fig.10 It is a schematic cross-sectional view of a circuit board assembly according to another embodiment of the present invention.

[0022] Main component symbols

[0023] Circuit board 10 Dielectric layer 11 Circuit layer 13 Conductive column 15 Solder mask 17 First circuit layer 131 Second circuit layer 132 The third circuit layer 133 Fourth circuit layer 134 Through slot 20 Metal Sheet 30、30a Ontology 31 Protrusion 33、33a Surface treatment layer 301 Conductive adhesive 41 Adhesive layer 42 Electronic components 50 wire 51 Storage tank 35 Conductive Materials 60 Heat dissipation materials 61 Circuit Board Assembly 100、100a

[0024] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] 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.

[0027] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] Please refer to Figures 1 to 4 A method for manufacturing a circuit board assembly according to an embodiment of the present application comprises the following steps:

[0029] Step S11, see Figure 1 , a circuit substrate 10 is provided. The circuit substrate 10 includes a dielectric layer 11, a circuit layer 13, at least one conductive column 15 and two solder mask layers 17. The conductive column 15 is embedded in the dielectric layer 11 and protrudes from the surface of the circuit layer 13. The dielectric layer 11, the circuit layer 13 and the conductive column 15 are located between the two solder mask layers 17.

[0030] Specifically, the conductive pillar 15 is completely covered by the dielectric layer 11 .

[0031] The circuit substrate 10 may be a single-layer circuit board, a double-layer circuit board or a multi-layer circuit board. The circuit substrate 10 may be a flexible circuit board, a rigid circuit board or a rigid-flexible circuit board.

[0032] In this embodiment, the circuit substrate 10 may be a multi-layer rigid-flexible circuit board. Specifically, the circuit substrate 10 may include a dielectric layer 11 and a first circuit layer 131, a second circuit layer 132, a third circuit layer 133 and a fourth circuit layer 134 stacked in sequence along the thickness direction of the dielectric layer 11. The first circuit layer 131 and the fourth circuit layer 134 are respectively located on opposite sides of the dielectric layer 11, and the second circuit layer 132 and the third circuit layer 133 are buried in the dielectric layer 11 and located between the first circuit layer 131 and the fourth circuit layer 134. The number of the conductive pillars 15 is two and they are arranged corresponding to the rigid board area of ​​the circuit substrate 10, and each of the conductive pillars 15 protrudes from the first circuit layer 131 toward one side of the fourth circuit layer 134.

[0033] A solder resist layer 17 is disposed on a side of the first circuit layer 131 away from the fourth circuit layer 134 , and another solder resist layer 17 is disposed on a side of the fourth circuit layer 134 away from the first circuit layer 131 .

[0034] In some other implementations, the conductive pillars 15 may also protrude from the surface of the second circuit layer 132 .

[0035] The conductive column 15 is directly formed by electroplating metal deposition, or by filling the conductive hole with conductive paste or other conductive materials. The shape of the conductive column 15 can be set as required, for example, it can be a regular or other irregular shape such as a cylinder, a truncated cone, a pyramid, a prism, etc.

[0036] Step S12, see Figure 2 A through slot 20 penetrating the circuit substrate 10 is provided along the stacking direction of the two solder mask layers 17 , and the conductive pillar 15 is at least partially exposed from the inner wall of the through slot 20 .

[0037] In this embodiment, the through slot 20 may penetrate the surface 151 of the conductive pillar 15 away from the first circuit layer 131. Preferably, the center line of the conductive pillar 15 along the stacking direction may coincide with the inner wall of the through slot 20.

[0038] Step S13, see Figure 3 A metal plate 30 is provided, and the metal plate 30 includes a body 31 and a protruding portion 33. The protruding portion 33 is protruded from one side of the body 31.

[0039] The width of the protruding portion 33 is smaller than the width of the through slot 20 , and the height of the protruding portion 33 may be smaller than the depth of the through slot 20 .

[0040] The metal plate 30 may be surface treated to form a surface treatment layer 301 to cover the body 31 and the protrusion 33, thereby protecting the body 31 and the protrusion 33. The surface treatment may be formed by chemical gold plating, chemical nickel plating, chemical target plating, electrolytic nickel plating or electroless nickel plating.

[0041] The metal plate 30 may be, but is not limited to, a steel plate, a copper plate, etc.

[0042] Step S14, see Figure 4 The metal plate 30 is stacked and bonded with the circuit substrate 10 having the through groove 20 , wherein the protruding portion 33 is received in the through groove 20 and bonded to the inner wall of the through groove 20 by a conductive adhesive 41 , thereby electrically connecting the conductive column 15 and the protruding portion 33 .

[0043] In this embodiment, the body 31 can also be bonded to the solder mask 17 of the circuit substrate 10 through an adhesive layer 42. The adhesive layer 42 can be a conductive adhesive layer or a non-conductive adhesive layer. Preferably, the conductive adhesive 41 is a conductive material with high thermal conductivity, which is conducive to the conduction and dissipation of heat.

[0044] In this embodiment, the body 31 may be located on a side of the first circuit layer 131 away from the fourth circuit layer 134 and bonded to the solder mask layer combined with the first circuit layer 131 .

[0045] The metal plate 30 is stacked and bonded with the circuit substrate 10, so that the metal plate 30 can quickly conduct the heat from the circuit substrate 10, which is beneficial to improve the heat dissipation effect of the circuit substrate 10. At the same time, the circuit substrate 10 is electrically connected to the protruding portion 33 through the conductive column 15 to achieve grounding from the inner wall of the through groove 20, and there is no need to open an opening on the solder mask to expose the electrical connection area to be electrically connected to the metal plate, thereby reducing the risk of the solder mask falling off due to the small attachment area, and also reducing the CAF risk.

[0046] In some embodiments, after step S14, the method for manufacturing the circuit board assembly may further include step S15, see Figure 5 An electronic component 50 is disposed on a side of the protruding portion 33 away from the main body 31 , and the electronic component 50 is electrically connected to the circuit substrate 10 .

[0047] Specifically, the electronic component 50 can be bonded to the side of the protrusion 33 away from the body 31, and can be accommodated in the through groove 20. The electronic component 50 can be but is not limited to a photosensitive chip. In some embodiments, the electronic component 50 can also be welded to the side of the protrusion 33 away from the body 31. The electronic component 50 can be connected to the circuit substrate 10 through a wire 51. In this embodiment, the electronic component 50 can be electrically connected to the fourth circuit layer 134 through the wire 51.

[0048] See also Figure 2 and Figures 6 to 8 , a method for manufacturing a circuit board assembly according to another embodiment of the present application comprises the following steps:

[0049] Step S21, see Figure 6 A metal plate 30a is provided, and the metal plate 30a includes a body 31 and a protruding portion 33a. The protruding portion 33a protrudes from one side of the body 31, and a receiving groove 35 is formed by a side of the protruding portion 33a that is away from the body 31 and is recessed toward the body 31.

[0050] In some embodiments, the metal plate 30a may be surface treated to form a surface treated layer 301 covering the entire metal plate 30a.

[0051] Step S22, as Figure 2 As shown, a circuit substrate 10 having the through slot 20 is provided.

[0052] Step S23, see Figure 7 The metal plate 30a and the circuit substrate 10 provided with the through groove 20 are stacked and bonded, wherein the protruding portion 33a is accommodated in the through groove 20, and the main body 31 is bonded to the solder mask 17 of the circuit substrate 10.

[0053] In this embodiment, the protruding portion 33a may be spaced apart from the inner wall of the through slot 20. The body 31 is bonded to the solder mask 17 of the circuit substrate 10 via an adhesive layer 42. The adhesive layer 42 may be a conductive adhesive layer or a non-conductive adhesive layer.

[0054] The metal plate 30 a and the circuit substrate 10 are stacked and bonded, which is beneficial for quickly conducting the heat transmitted from the circuit substrate 10 through the metal plate 30 a , and is beneficial for improving the heat dissipation effect of the circuit substrate 10 .

[0055] Step S24, see Figure 8 A conductive material 60 is filled between the protruding portion 33 a and the through-slot 20 to electrically connect the protruding portion 33 a and the conductive column 15 .

[0056] The circuit substrate 10 is electrically connected to the protruding portion 33a through the conductive material 60 to achieve grounding from the inner wall of the through groove 20, thereby eliminating the need to open an opening in the solder mask to expose the electrical connection area for electrical connection with the metal plate, thereby reducing the risk of the solder mask falling off due to the small attachment area, and also reducing the CAF risk.

[0057] The conductive material 60 may be conductive paste, conductive glue, etc. Preferably, the conductive material 60 is a conductive material with high thermal conductivity, which is beneficial to the conduction and dissipation of heat.

[0058] In some embodiments, see Figure 8 Step S24 may include installing an electronic component 50 in the receiving groove 35 and filling a conductive material 60 between the protruding portion 33 a and the through groove 20 .

[0059] The electronic component 50 is electrically connected to the circuit substrate 10 .

[0060] In some embodiments, see Figure 8 Step S24 may further include filling a heat dissipation material 61 between the receiving groove 35 and the gap between the electronic component 50 .

[0061] The heat dissipation material 61 may be, but is not limited to, thermally conductive silicone. In some embodiments, the heat dissipation material 61 and the conductive material 60 may be made of the same material.

[0062] See also Fig. 9 A circuit board assembly 100 according to an embodiment of the present application comprises a circuit substrate 10 and a metal plate 30. The circuit substrate 10 comprises a dielectric layer 11, a circuit layer 13, at least one conductive column 15 and two solder mask layers 17. The conductive column 15 is embedded in the dielectric layer 11 and protrudes from the surface of the circuit layer 13. The dielectric layer 11, the circuit layer 13 and the conductive column 15 are located between the two solder mask layers 17. A through slot 20 penetrates the circuit substrate 10 along the stacking direction of the two solder mask layers 17, and the conductive column 15 is at least partially exposed from the inner wall of the through slot 20. The metal plate 30 comprises a body 31 stacked and attached to one side of the solder mask layer 17 away from the other solder mask layer 17, and a protruding portion 33 protruding from one side of the body 31 and accommodated in the through slot 20. The protruding portion 33 is electrically connected to the conductive column 15 through a conductive material 60.

[0063] The conductive material 60 may be conductive paste, conductive glue or other conductive materials with high thermal conductivity, which is beneficial for heat conduction and dissipation.

[0064] Specifically, the conductive pillar 15 is completely covered by the dielectric layer 11 .

[0065] The circuit substrate 10 may be a single-layer circuit board, a double-layer circuit board or a multi-layer circuit board. The circuit substrate 10 may be a flexible circuit board, a rigid circuit board or a rigid-flexible circuit board.

[0066] In this embodiment, the circuit substrate 10 may be a multi-layer rigid-flexible circuit board. Specifically, the circuit substrate 10 may include a dielectric layer 11 and a first circuit layer 131, a second circuit layer 132, a third circuit layer 133 and a fourth circuit layer 134 stacked in sequence along the thickness direction of the dielectric layer 11. The first circuit layer 131 and the fourth circuit layer 134 are respectively located on opposite sides of the dielectric layer 11, and the second circuit layer 132 and the third circuit layer 133 are buried in the dielectric layer 11 and located between the first circuit layer 131 and the fourth circuit layer 134. The number of the conductive pillars 15 is two and they are arranged corresponding to the rigid board area of ​​the circuit substrate 10, and each of the conductive pillars 15 protrudes from the first circuit layer 131 toward one side of the fourth circuit layer 134.

[0067] A solder resist layer 17 is disposed on a side of the first circuit layer 131 away from the fourth circuit layer 134 , and another solder resist layer 17 is disposed on a side of the fourth circuit layer 134 away from the first circuit layer 131 .

[0068] In some other implementations, the conductive pillars 15 may also protrude from the surface of the second circuit layer 132 .

[0069] The conductive column 15 is directly formed by electroplating metal deposition, or by filling the conductive hole with conductive paste or other conductive materials. The shape of the conductive column 15 can be set as required, for example, it can be a regular or other irregular shape such as a cylinder, a truncated cone, a pyramid, a prism, etc.

[0070] In this embodiment, the through slot 20 may penetrate the surface 151 of the conductive pillar 15 away from the first circuit layer 131. Preferably, the center line of the conductive pillar 15 along the stacking direction may coincide with the inner wall of the through slot 20.

[0071] The width of the protruding portion 33 is smaller than the width of the through slot 20, and the height of the protruding portion 33 may be smaller than the depth of the through slot 20. In this embodiment, the protruding portion 33 may be spaced apart from the inner wall of the through slot 20. The conductive material 60 is disposed between the protruding portion 33 and the inner wall of the through slot 20.

[0072] The metal plate 30 may be surface treated to form a surface treatment layer 301 to cover the body 31 and the protrusion 33, thereby protecting the body 31 and the protrusion 33. The surface treatment may be formed by chemical gold plating, chemical nickel plating, chemical target plating, electrolytic nickel plating or electroless nickel plating.

[0073] The metal plate 30 may be, but is not limited to, a steel plate, a copper plate, etc.

[0074] In this embodiment, the body 31 can also be bonded to the solder mask 17 of the circuit substrate 10 through an adhesive layer 42. The adhesive layer 42 can be a conductive adhesive layer or a non-conductive adhesive layer. Preferably, the thermal conductivity of the adhesive layer 42 is high, thereby facilitating heat conduction.

[0075] In this embodiment, the body 31 may be located on a side of the first circuit layer 131 away from the fourth circuit layer 134 and bonded to the solder mask layer combined with the first circuit layer 131 .

[0076] The metal plate 30 is stacked and attached to the circuit substrate 10, so that the metal plate 30 can quickly conduct the heat from the circuit substrate 10, which is beneficial to improve the heat dissipation effect of the circuit substrate 10. At the same time, the circuit substrate 10 is electrically connected to the protruding portion 33 through the conductive column 15 to achieve grounding from the inner wall of the through groove 20, and there is no need to open an opening on the solder mask to expose the electrical connection area to be electrically connected to the metal plate, which reduces the risk of the solder mask falling off due to the small attachment area, and also reduces the CAF risk. In addition, the metal plate 30 can also be used as a reinforcement plate on the circuit substrate 10 to reinforce specific areas of the circuit substrate 10.

[0077] In some embodiments, see Fig.10 A receiving groove 35 is formed from a side of the protruding portion 33 away from the main body 31 and recessed toward the main body 31 .

[0078] The circuit board assembly 100 (100a) may further include an electronic component 50 mounted on the metal plate 30. In some embodiments, Fig. 9 As shown, the electronic component 50 is mounted on the side of the protruding portion 33 away from the body 31, and the electronic component 50 is electrically connected to the circuit substrate 10. In other embodiments, as Fig.10 As shown, the electronic component 50 is installed in the receiving groove 35 and is electrically connected to the circuit substrate 10. Further, the gap between the electronic component 50 and the receiving groove 35 can also be filled with a heat dissipation material 61. The heat dissipation material 61 can be but is not limited to thermally conductive silicone. In some embodiments, the heat dissipation material 61 and the conductive material 60 can be made of the same material.

[0079] In the above-mentioned circuit board assembly and its manufacturing method of the present application, the metal plate is stacked and attached to the circuit substrate, so that the metal plate can quickly conduct the heat transmitted from the circuit substrate, which is beneficial to improving the heat dissipation effect of the circuit substrate. At the same time, the circuit substrate is electrically connected to the protruding portion through the conductive column to achieve grounding from the inner wall of the through groove, and there is no need to open an opening on the solder mask to expose the electrical connection area to be electrically connected to the metal plate, which reduces the risk of the solder mask falling off due to the small attachment area, and also reduces the CAF risk, which is beneficial to extend the service life of the circuit board assembly.

[0080] 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 method for manufacturing a circuit board assembly, comprising the following steps: A circuit substrate is provided, comprising a dielectric layer, a circuit layer, at least one conductive column and two solder mask layers, wherein the conductive column is embedded in the dielectric layer and protrudes from the surface of the circuit layer, and the dielectric layer, the circuit layer and the conductive column are located between the two solder mask layers; A through slot is provided along the stacking direction of the two solder resist layers and penetrates the circuit substrate, wherein at least a portion of the conductive column is exposed from the inner wall of the through slot; A metal plate is provided, comprising a main body and a protruding portion protruding from one side of the main body; a side of the protruding portion facing away from the main body is recessed toward the main body to form a receiving groove; The metal plate is stacked and bonded to the circuit substrate provided with the through groove, wherein the body is bonded to one of the solder resist layers, and the protruding portion is received in the through groove and electrically connected to the conductive column through a conductive material; When the through slot is formed, the surface of the conductive column facing away from the body is penetrated; Installing an electronic component in the receiving slot and electrically connecting it to the circuit substrate; as well as The gap between the electronic component and the receiving groove is filled with heat dissipation material.

2. The method for manufacturing a circuit board assembly according to claim 1, wherein: The conductive material is conductive paste or conductive glue.

3. The method for manufacturing a circuit board assembly according to claim 1, wherein: The through slot penetrates the circuit substrate along a center line of the conductive column in a stacking direction of the two solder resist layers.

4. A circuit board assembly, comprising a circuit substrate and a metal plate, wherein the circuit substrate comprises a dielectric layer, a circuit layer, at least one conductive column and two solder mask layers, wherein the conductive column is buried in the dielectric layer and protrudes from the surface of the circuit layer, and the dielectric layer, the circuit layer and the conductive column are located between the two solder mask layers; characterized in that: A through slot penetrates the circuit substrate along the stacking direction of the two solder mask layers, and the conductive column is at least partially exposed from the inner wall of the through slot; the metal plate includes a main body stacked and attached to the side of one solder mask layer away from the other solder mask layer, and a protruding portion protruding from one side of the main body and accommodated in the through slot, wherein the protruding portion is electrically connected to the conductive column through a conductive material; the side of the protruding portion away from the main body is recessed toward the main body to form a receiving slot, and the circuit board assembly also includes an electronic component, which is installed in the receiving slot and electrically connected to the circuit substrate, and the heat dissipation material fills the gap between the electronic component and the receiving slot; the surface of the conductive column away from the main body is penetrated by the through slot.

5. The circuit board assembly according to claim 4, wherein: The conductive material is conductive paste or conductive glue.

6. The circuit board assembly according to claim 4, wherein: The through slot penetrates the circuit substrate along a center line of the conductive column in a stacking direction of the two solder resist layers.

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