Flexible circuit board connection structure and method of manufacturing the same

Abstract

The application provides a manufacturing method of a flexible circuit board connecting structure, comprising the following steps: providing a metal sheet; forming a copper column on the metal sheet to obtain a metal sheet structure; providing a flexible circuit board structure, wherein the flexible circuit board structure comprises a flexible circuit board connecting structure, a grounding wire and a cover film which are sequentially stacked, and the cover film is provided with a through hole; forming a conductive adhesive layer on the cover film, and covering the through hole with the conductive adhesive layer; and placing the metal sheet structure on the conductive adhesive layer and pressing to fill the conductive adhesive layer in the through hole to connect with the grounding wire, and to coat the copper column with the conductive adhesive layer, so as to obtain the flexible circuit board connecting structure, wherein the copper column is located in the through hole. The conductive adhesive layer in the application is in good conduction with the grounding wire. The application also provides a flexible circuit board connecting structure manufactured by the manufacturing method.

Description

Technical Field

[0001] This application relates to the field of flexible circuit board technology, and in particular to a flexible circuit board connection structure and its manufacturing method. Background Technology

[0002] With the development of electronic technology, electronic products are becoming increasingly sophisticated in structure and increasingly feature-rich. Flexible circuit boards (PCBs) in electronic products are characterized by their ability to be bent freely, folded with light weight, small size, thinness, and easy installation. In the design and manufacturing process of flexible circuit boards, conductive adhesive layers combined with metal sheets are typically used for reinforcement and grounding. However, during the lamination process, a certain thickness difference exists between the grounding wire and the conductive adhesive layer on the flexible circuit board, leading to poor conductivity between the conductive adhesive layer and the grounding wire, and consequently, a lack of grounding functionality. Summary of the Invention

[0003] In view of this, this application provides a method for manufacturing a flexible circuit board connection structure with good conductivity between the conductive adhesive layer and the grounding wire.

[0004] Additionally, it is necessary to provide a flexible circuit board connection structure manufactured by the above method.

[0005] One embodiment of this application provides a method for manufacturing a flexible circuit board connection structure, including the following steps:

[0006] Provide metal sheets;

[0007] Copper pillars are formed on the metal sheet to obtain a metal sheet structure;

[0008] A flexible circuit board structure is provided, the flexible circuit board structure including a flexible circuit board connection structure, a grounding wire and a cover film stacked in sequence, the cover film having through holes, and a portion of the grounding wire being exposed through the through holes;

[0009] A conductive adhesive layer is formed on the cover film, and the conductive adhesive layer covers the through-hole; and

[0010] The metal sheet structure is placed on the conductive adhesive layer and pressed together so that the conductive adhesive layer fills the through hole to connect with the ground wire, and the conductive adhesive layer covers the copper pillar, thereby obtaining the flexible circuit board connection structure, wherein the copper pillar is located in the through hole.

[0011] One embodiment of this application also provides a flexible circuit board connection structure, including:

[0012] Metal sheet;

[0013] A copper pillar is located on the metal sheet;

[0014] A flexible circuit board structure, comprising a flexible circuit board connection structure, a grounding wire, and a cover film stacked sequentially, wherein the cover film has through holes, and a portion of the grounding wire is exposed through the through holes; and

[0015] A conductive adhesive layer is located on the cover film, and a portion of the conductive adhesive layer is located in the through hole to connect with the grounding wire. The conductive adhesive layer covers the copper pillar, and the copper pillar is located in the through hole.

[0016] This application forms the copper pillars on the metal sheet. When the metal sheet structure is placed on the conductive adhesive layer and pressed together, the copper pillars ensure that the conductive adhesive layer completely fills the through-hole, reducing the probability of poor conductivity between the conductive adhesive layer and the grounding wire. This facilitates the grounding function of the flexible circuit board connection structure. Simultaneously, the copper pillars also contribute to the thinning of the conductive adhesive layer. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of a metal sheet provided in an embodiment of this application.

[0018] Figure 2 Is Figure 1 The cross-sectional view shown is of a metal sheet with multiple heat dissipation slots.

[0019] Figure 3 Is Figure 2 The cross-sectional views shown are of the metal sheet after nickel layers have been formed on its surface and sides, as well as on the inner wall and bottom of the heat sink.

[0020] Figure 4 Is Figure 3 The cross-sectional view shows a metal sheet with a first protective layer and a second protective layer formed on opposite surfaces, and multiple copper pillars formed on a nickel layer through the first protective layer.

[0021] Figure 5 It is Figure 4 The cross-sectional view shown is after the first and second protective layers have been removed, and a heat dissipation layer has been formed on the surface and sides of the copper pillar and on the nickel layer.

[0022] Figure 6 This is a cross-sectional view of a flexible circuit board structure provided in an embodiment of this application.

[0023] Figure 7 Is Figure 6 The cross-sectional view shown is of the cover film after a conductive adhesive layer has been formed.

[0024] Figure 8 It is Figure 5 The metal sheet structure shown is placed Figure 7 The cross-sectional view shown is of the conductive adhesive layer.

[0025] Figure 9 It is Figure 8 The cross-sectional view of the flexible circuit board connection structure obtained after the metal sheet structure and conductive adhesive layer are laminated onto the flexible circuit board structure.

[0026] Explanation of main component symbols

[0027] Flexible circuit board connection structure 100

[0028] Metal sheet 10

[0029] Heat sink 11

[0030] Nickel layer 20

[0031] First protective layer 30

[0032] Second protective layer 31

[0033] Copper pillar 40

[0034] Heat dissipation layer 50

[0035] Metal sheet structure 60

[0036] Flexible circuit board structure 70

[0037] Flexible circuit board 71

[0038] Grounding wire 72

[0039] Covering membrane 73

[0040] Through hole 731

[0041] Conductive adhesive layer 80

[0042] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0043] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0045] To further illustrate the technical means and effects adopted by this application in achieving its intended purpose, the following detailed description of this application is provided in conjunction with the accompanying drawings and preferred embodiments.

[0046] One embodiment of this application provides a method for manufacturing a flexible circuit board connection structure, including the following steps:

[0047] Step S11, please refer to Figure 1 10 metal sheets are provided.

[0048] In this embodiment, the metal sheet 10 can be a steel sheet. In this embodiment, the thickness δ of the metal sheet 10 can be 20-500 μm.

[0049] Step S12, please refer to Figure 2 Multiple heat dissipation grooves 11 are formed in the metal sheet 10.

[0050] Specifically, the heat dissipation groove 11 can be formed by drilling at a fixed depth.

[0051] In this embodiment, each of the heat dissipation grooves 11 does not penetrate the metal sheet 10. That is, each of the heat dissipation grooves 11 penetrates one surface of the metal sheet 10 and ends at the other surface of the metal sheet 10.

[0052] In this embodiment, the depth d of each heat dissipation groove 11 can be greater than (δ-10)μm, that is, the depth d of each heat dissipation groove 11 can be in the range of 10-490μm.

[0053] In this embodiment, the inner diameter r1 of each heat dissipation groove 11 can be 50-200μm.

[0054] Step S13, please refer to Figure 3 Nickel layers 20 are formed on the surface and sides of the metal sheet 10, as well as on the inner wall and bottom surface of the heat dissipation groove 11.

[0055] Specifically, the nickel layer 20 is formed on the upper surface of the metal sheet 10, the lower surface of the metal sheet 10, the two sides of the metal sheet 10, and the inner wall and bottom surface of the heat dissipation groove 11.

[0056] In this embodiment, the thickness of the nickel layer 20 can be 2-8 μm.

[0057] Step S14, please refer to Figure 4 A first protective layer 30 and a second protective layer 31 are formed on the two opposing surfaces of the metal sheet 10, respectively.

[0058] The first protective layer 30 is located on the surface of the metal sheet 10 where the heat dissipation groove 11 is not formed, and the second protective layer 31 is located on the surface of the metal sheet 10 where the heat dissipation groove 11 is formed. An opening (not shown in the figure) is formed in the first protective layer 30, and the opening penetrates the first protective layer 30.

[0059] Step S15: A plurality of copper pillars 40 are formed on the nickel layer 20 through the first protective layer 30.

[0060] In this embodiment, each copper pillar 40 and each heat sink 11 are positioned correspondingly. Multiple copper pillars 40 can be formed on the nickel layer 20 using an additive method.

[0061] It is understood that in other embodiments, the second protective layer 31 may be omitted. That is, the first protective layer 30 is formed only on the surface of the metal sheet 10 where the heat dissipation groove 11 is not formed.

[0062] In this embodiment, the outer diameter r2 of each copper pillar 40 can be (r1+50) μm, that is, the range of the outer diameter r2 of each copper pillar 40 can be 100-250 μm. That is, the outer diameter r2 of each copper pillar 40 is greater than the inner diameter r1 of each heat dissipation groove 11.

[0063] Step S16, please refer to Figure 5 The first protective layer 30 and the second protective layer 31 are removed respectively.

[0064] Step S17: A heat dissipation layer 50 is formed on the surface and side of the copper pillar 40 and on the nickel layer 20 to obtain a metal sheet structure 60.

[0065] Specifically, the heat dissipation layer 50 is formed on the upper and side surfaces of the copper pillar 40, as well as on all of the nickel layers 20.

[0066] In this embodiment, the heat dissipation layer 50 is made of graphene.

[0067] In this embodiment, the thickness of the heat dissipation layer 50 can be 0.5-3 μm.

[0068] Step S18, please refer to Figure 6 , providing flexible circuit board structure 70.

[0069] In this embodiment, the flexible circuit board structure 70 includes a flexible circuit board 71, a grounding wire 72, and a cover film 73 stacked sequentially. The cover film 73 has a through hole 731 that penetrates the cover film 73, and a portion of the grounding wire 72 is exposed through the through hole 731.

[0070] In this embodiment, the thickness D of the cover film 73 can be 20-200 μm. It can be understood that the depth of the through-hole 731 is the same as the thickness of the cover film 73, also 20-200 μm.

[0071] Step S19, please refer to Figure 7 A conductive adhesive layer 80 is formed on the cover film 73, and the conductive adhesive layer 80 covers the through hole 731.

[0072] For step S20, please refer to... Figure 8 and Figure 9 The metal sheet structure 60 is placed on the conductive adhesive layer 80 and pressed together so that the conductive adhesive layer 80 fills the through hole 731 to connect with the ground wire 72, and the conductive adhesive layer 80 covers the copper pillar 40, thereby obtaining the flexible circuit board connection structure 100.

[0073] The copper pillar 40 is located within the through hole 731. It should be noted that the copper pillar 40 ensures that the conductive adhesive layer 80 completely fills the through hole 731, meaning there are no gaps between the conductive adhesive layer 80 and the grounding wire 72.

[0074] In this embodiment, after the conductive adhesive layer 80 is filled into the through hole 731, the conductive adhesive layer 80 can be baked to set the conductive adhesive layer 80.

[0075] In this embodiment, the height h of each copper pillar 40 can be greater than (D-10) μm, that is, the height h of each copper pillar 40 can be in the range of 10-190 μm.

[0076] Please see Figure 9 An embodiment of this application also provides a flexible circuit board connection structure 100, which includes a metal sheet 10, a nickel layer 20, a copper pillar 40, a heat dissipation layer 50, a flexible circuit board structure 70, and a conductive adhesive layer 80.

[0077] In this embodiment, the metal sheet 10 can be a steel sheet. In this embodiment, the thickness δ of the metal sheet 10 can be 20-500 μm.

[0078] The metal sheet 10 has multiple heat dissipation grooves 11. Each heat dissipation groove 11 does not penetrate the metal sheet 10. That is, each heat dissipation groove 11 penetrates one surface of the metal sheet 10 and terminates at the other surface of the metal sheet 10.

[0079] In this embodiment, the depth d of each heat dissipation groove 11 can be greater than (δ-10)μm, that is, the depth d of each heat dissipation groove 11 can be in the range of 10-490μm.

[0080] In this embodiment, the inner diameter r1 of each heat dissipation groove 11 can be 50-200μm.

[0081] The nickel layer 20 is located on the surface and sides of the metal sheet 10, as well as on the inner wall and bottom surface of the heat dissipation groove 11. Specifically, the nickel layer 20 is located on the upper surface of the metal sheet 10, the lower surface of the metal sheet 10, the two sides of the metal sheet 10, and on the inner wall and bottom surface of the heat dissipation groove 11.

[0082] In this embodiment, the thickness of the nickel layer 20 can be 2-8 μm.

[0083] The copper pillar 40 is located on the surface of the metal sheet 10 where the heat dissipation groove 11 is not formed. Specifically, the copper pillar 40 is located on the nickel layer 20. Each copper pillar 40 corresponds to each heat dissipation groove 11.

[0084] In this embodiment, the outer diameter r2 of each copper pillar 40 can be (r1+50) μm, that is, the range of the outer diameter r2 of each copper pillar 40 can be 100-250 μm. That is, the outer diameter r2 of each copper pillar 40 is greater than the inner diameter r1 of each heat dissipation groove 11.

[0085] The heat dissipation layer 50 is located on the surface and sides of the copper pillar 40, as well as on the nickel layer 20. Specifically, the heat dissipation layer 50 is located on the upper surface and sides of the copper pillar 40, as well as on all of the nickel layers 20.

[0086] In this embodiment, the heat dissipation layer 50 is made of graphene.

[0087] In this embodiment, the thickness of the heat dissipation layer 50 can be 0.5-3 μm.

[0088] In this embodiment, the flexible circuit board structure 70 includes a flexible circuit board 71, a grounding wire 72, and a cover film 73 stacked sequentially. The cover film 73 has a through hole 731 that penetrates the cover film 73, and a portion of the grounding wire 72 is exposed through the through hole 731.

[0089] In this embodiment, the thickness D of the cover film 73 can be 20-200 μm. It can be understood that the depth of the through-hole 731 is the same as the thickness of the cover film 73, also 20-200 μm.

[0090] The conductive adhesive layer 80 is located on the cover film 73, and a portion of the conductive adhesive layer 80 fills the through hole 731 to connect with the grounding wire 72. The conductive adhesive layer 80 covers the copper pillar 40, and the copper pillar 40 is located in the through hole 731.

[0091] It should be noted that the conductive adhesive layer 80 completely fills the through hole 731. That is, there are no gaps between the conductive adhesive layer 80 and the grounding wire 72.

[0092] In this embodiment, the height h of each copper pillar 40 can be greater than (D-10) μm, that is, the height h of each copper pillar 40 can be in the range of 10-190 μm.

[0093] In this application, the copper pillar 40 is formed on the metal sheet 10. When the metal sheet structure 60 is placed on the conductive adhesive layer 80 and pressed together, the copper pillar 40 ensures that the conductive adhesive layer 80 completely fills the through hole 731, reducing the probability of poor conductivity between the conductive adhesive layer 80 and the grounding wire 72. This facilitates the grounding function of the flexible circuit board connection structure 100. Simultaneously, the copper pillar 40 also contributes to the thinning of the conductive adhesive layer 80.

[0094] This application also forms nickel layers 20 on the surface and sides of the metal sheet 10, as well as on the inner wall and bottom surface of the heat sink 11. Since the nickel layer 20 has an electronic shielding effect, it can reduce interference from external electronic signals to the flexible circuit board connection structure 100. Simultaneously, the nickel layer 20 can also prevent the metal sheet 10 from oxidizing.

[0095] This application also forms a heat dissipation layer 50 on the surface and sides of the copper pillar 40 and on the nickel layer 20. The heat dissipation layer 50 can improve the heat dissipation effect of the metal sheet 10 and the copper pillar 40, thereby improving the heat dissipation effect of the flexible circuit board connection structure 100. At the same time, the heat dissipation layer 50 also provides a certain degree of protection for the copper pillar 40 and the metal sheet 10.

[0096] In this application, the inner diameter of each heat dissipation groove 11 is smaller than the outer diameter of each copper pillar 40, which facilitates air exchange and heat dissipation, thereby improving the heat dissipation effect of the metal sheet structure 60 and, consequently, the heat dissipation effect of the flexible circuit board connection structure 100. Simultaneously, since the outer diameter of each copper pillar 40 is larger than the inner diameter of each heat dissipation groove 11, it also helps to ensure the rigidity of the metal sheet 10.

[0097] The above description is merely an optimized implementation of this application, but in actual applications, it should not be limited to this implementation.

Claims

1. A method for fabricating a flexible circuit board connection structure, characterized in that, Includes the following steps: Provide metal sheets; Copper pillars are formed on the metal sheet to obtain a metal sheet structure; A flexible circuit board structure is provided, the flexible circuit board structure including a flexible circuit board connection structure, a grounding wire and a cover film stacked in sequence, the cover film having through holes, and a portion of the grounding wire being exposed through the through holes; A conductive adhesive layer is formed on the cover film, and the conductive adhesive layer covers the through-hole; and The metal sheet structure is placed on the conductive adhesive layer and pressed together so that the conductive adhesive layer completely fills the through hole to connect with the ground wire without gaps, and the conductive adhesive layer covers the copper pillar, thereby obtaining the flexible circuit board connection structure, wherein the copper pillar is located in the through hole.

2. The method for manufacturing the flexible circuit board connection structure as described in claim 1, characterized in that, After providing the metal sheet, the manufacturing method further includes: Heat dissipation grooves are formed in the metal sheet; The copper pillar and the heat dissipation groove are located on opposite surfaces of the metal sheet, and their positions correspond to each other.

3. The method for manufacturing the flexible circuit board connection structure as described in claim 2, characterized in that, After creating the heat dissipation groove in the metal sheet, the manufacturing method further includes: A nickel layer is formed on the surface and sides of the metal sheet, as well as on the inner wall and bottom surface of the heat dissipation groove; The copper pillar is formed on the nickel layer.

4. The method for manufacturing the flexible circuit board connection structure as described in claim 3, characterized in that, After the copper pillar is formed on the metal sheet, the manufacturing method further includes: Heat dissipation layers are formed on the surface and sides of the copper pillar, as well as on the nickel layer.

5. The method for manufacturing the flexible circuit board connection structure as described in claim 2, characterized in that, The inner diameter of the heat dissipation groove is smaller than the outer diameter of the copper pillar.

6. A flexible circuit board connection structure, characterized in that, include: Metal sheet; A copper pillar is located on the metal sheet; A flexible circuit board structure, comprising a flexible circuit board connection structure, a grounding wire, and a cover film stacked sequentially, wherein the cover film has through holes, and a portion of the grounding wire is exposed through the through holes; and A conductive adhesive layer is located on the cover film, and a portion of the conductive adhesive layer is completely located in the through hole to connect with the grounding wire without gaps. The conductive adhesive layer covers the copper pillar, and the copper pillar is located in the through hole.

7. The flexible circuit board connection structure as described in claim 6, characterized in that, The metal sheet has heat dissipation grooves, and the heat dissipation grooves and the copper pillars are located on opposite surfaces of the metal sheet, with the positions of the heat dissipation grooves and the copper pillars corresponding to each other.

8. The flexible circuit board connection structure as described in claim 7, characterized in that, Also includes: A nickel layer is located on the surface and sides of the metal sheet, as well as on the inner wall and bottom surface of the heat dissipation groove; The copper pillar is located on the nickel layer.

9. The flexible circuit board connection structure as described in claim 8, characterized in that, Also includes: A heat dissipation layer is located on the surface and sides of the copper pillar, as well as on the nickel layer.

10. The flexible circuit board connection structure as described in claim 7, characterized in that, The inner diameter of the heat dissipation groove is smaller than the outer diameter of the copper pillar.

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