Multi-material circuit assembly board soft board tear-resistant design structure

Abstract

The utility model relates to a kind of soft board tear-resistant design structure of multi-material circuit combination board.It solves the problem that soft board and hard board boundary exist shear force in prior art, and soft board is easily torn.It includes the aluminum sheet setting in bottom layer, the lower line layer is set in the upper end of aluminum sheet, the upper and lower sides of lower line layer are provided with heat dissipation insulation structure, aluminum sheet, lower line layer and heat dissipation insulation structure jointly constitute aluminum substrate, and the upper layer soft board assembly is connected by glue isolation structure on the upper layer of aluminum substrate.The utility model has the advantages that it has the three-dimensional bending function of soft board and the high-thermal-conductivity function of hard board;Effectively solve the problem that soft board is easily torn, improve product reliability.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, specifically to a tear-resistant design structure for a multi-material circuit board flexible circuit board. Background Technology

[0002] Traditional flexible printed circuit boards (FPCBs) have tamper-evident holes at the ends of the traces to prevent tearing caused by pulling, folding, passing through shaft holes, or maintenance operations. Because traditional FPCBs have simple traces and large enough spacing between traces, large circular tamper-evident holes are sufficient to prevent tearing. However, with current technological advancements, the complexity of FPCB traces has increased, resulting in smaller spacing between traces. Existing tamper-evident hole designs are now too large and can negatively impact the trace layout. Furthermore, because the FPCB passes through the sharp edges of rigid boards, shear forces exist at these boundaries, making the FPCB prone to tearing during manufacturing, transportation, surface mount technology (SMT), and assembly. This can lead to product malfunction and affect product quality.

[0003] To address the shortcomings of existing technologies, researchers have conducted extensive research and proposed various solutions. For example, Chinese patent literature discloses a tear-resistant structure for flexible circuit boards [CN104869745B], which includes at least one cutting line formed in an extension section of a flexible circuit board, and a stress-directing cutting segment extending from at least one end of the cutting line. The cutting direction of the stress-directing cutting segment forms an angle difference with the extension direction, serving as the tear-resistant structure for the flexible circuit board. The extension section of the flexible circuit board is also folded along the cutting line. The terminating end of the stress-directing cutting segment may also be connected to form a tear-resistant hole.

[0004] The above solution has solved the problem of tear hole design affecting the wiring of flexible circuit boards to a certain extent in the existing technology. However, the solution still has many shortcomings, such as shear force at the boundary between the flexible board and the rigid board, which can easily cause the flexible board to tear and affect product quality. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a tear-resistant design structure for a multi-material circuit board flexible circuit board.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a multi-material circuit board flexible board tear-resistant design structure, including an aluminum sheet disposed on the bottom layer, a lower circuit layer disposed on the upper end of the aluminum sheet, and heat dissipation and insulation structures disposed on the upper and lower sides of the lower circuit layer. The aluminum sheet, the lower circuit layer and the heat dissipation and insulation structures together constitute an aluminum substrate, and an upper flexible board assembly is connected to the upper layer of the aluminum substrate through an adhesive bonding isolation structure.

[0007] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, a solder resist layer is provided between the lower circuit layer and the adhesive bonding isolation structure.

[0008] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, a horizontally arranged wire passage is provided in the middle of the lower circuit layer, and several vertically arranged wire holes are also provided on the lower circuit layer and on both sides of the wire passage.

[0009] In the above-mentioned multi-material circuit board flexible board tear-resistant design structure, a heat dissipation film layer is provided circumferentially on the lower circuit layer, and heat dissipation through holes that are interconnected with the wiring channels are provided on the heat dissipation film layer.

[0010] In the above-mentioned multi-material circuit board flexible board tear-resistant design structure, the heat dissipation and insulation structure includes heat dissipation layers set on the upper and lower sides of the lower circuit layer, heat dissipation film layer and heat dissipation layer are connected to each other, and an insulation layer is set between the heat dissipation layer on the lower side and the aluminum sheet.

[0011] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, the upper flexible circuit board assembly includes a PI layer, an upper AD adhesive layer is provided on the upper end of the PI layer, and an upper circuit layer is provided on the side of the upper AD adhesive layer away from the PI layer, and a protective film layer is provided on the surface of the upper circuit layer.

[0012] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, the protective film layer includes a plastic film layer that is tightly attached to the surface of the upper circuit layer, and a waterproof and dustproof coating is provided on the upper layer of the plastic film layer.

[0013] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, the adhesive bonding isolation structure includes a lower AD adhesive layer, and several isolation layers are provided inside the lower AD adhesive layer.

[0014] In the above-mentioned multi-material circuit board flexible board tear-resistant design structure, isolation support rubber seats are provided between the isolation layers, and elastic connectors are provided on the outside of the isolation layers. The elastic connectors on the upper side are connected, and the elastic connectors on the lower side are connected to the solder mask layer.

[0015] In the above-mentioned multi-material circuit board flexible circuit board tear-resistant design structure, the wire holes are staggered on the upper and lower sides of the wire passage.

[0016] Compared with the prior art, the advantages of this utility model are: it rationally and effectively combines the bottom aluminum substrate rigid board with the upper flexible board assembly to achieve dense control circuit wiring, which has both the three-dimensional bending function of the flexible board and the high thermal conductivity of the rigid board; it effectively solves the problem of easy tearing of the flexible board and improves product reliability. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the overall structure of this utility model;

[0018] Figure 2 This is a cross-sectional view of the lower circuit layer in this utility model;

[0019] Figure 3 This is a schematic diagram of the heat dissipation and insulation structure in this utility model;

[0020] Figure 4 This is a cross-sectional view of the adhesive bonding and isolation structure in this utility model;

[0021] In the figure: Aluminum substrate 1, Aluminum sheet 11, Lower circuit layer 12, Through-hole 121, Through-hole 122, Heat dissipation film layer 123, Heat dissipation through-hole 124, Heat dissipation insulation structure 2, Heat dissipation layer 21, Insulation layer 22, Adhesive bonding isolation structure 3, Lower AD adhesive layer 31, Isolation layer 32, Isolation support rubber seat 33, Elastic connector 34, Upper flexible board assembly 4, PI layer 41, Upper AD adhesive layer 42, Upper circuit layer 43, Protective film layer 44, Solder resist layer 5. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1-4 As shown, the multi-material circuit board flexible circuit board has a tear-resistant design structure, including an aluminum sheet 11 on the bottom layer, a lower circuit layer 12 on the upper end of the aluminum sheet 11, and heat dissipation and insulation structures 2 on the upper and lower sides of the lower circuit layer 12. The aluminum sheet 11, the lower circuit layer 12 and the heat dissipation and insulation structures 2 together constitute an aluminum substrate 1. The upper layer of the aluminum substrate 1 is connected to the upper flexible circuit board assembly 4 through an adhesive isolation structure 3.

[0024] The aluminum sheet 11 utilizes the rigidity of metal to provide stable support for the overall structure, preventing the soft board from deforming excessively due to the lack of support at the bottom layer; at the same time, aluminum has good thermal conductivity, which can indirectly receive the heat conducted from the upper layer and diffuse it outward, thus assisting in heat dissipation.

[0025] A solder resist layer 5 is provided between the lower circuit layer 12 and the adhesive bonding isolation structure 3.

[0026] As can be seen, a horizontally arranged wire passage 121 is provided in the middle of the lower wiring layer 12, and several vertically arranged wire holes 122 are also provided on the lower wiring layer 12 and on both sides of the wire passage 121.

[0027] The wiring channel 121 provides horizontal routing space for the lines, while the vertical wire holes 122 on the top and bottom sides meet the vertical conduction requirements of the lines, realizing multi-layer wiring. The two work together to complete the complex layout of the underlying circuit.

[0028] In addition, the wire guide hole 122 is staggered on the upper and lower sides of the wire guide channel.

[0029] The staggered arrangement of the through hole 122 can reduce interference between lines and avoid the local reduction in strength of the lower line layer 12 caused by concentrated openings, thereby indirectly improving its tear resistance and preventing stress concentration fracture at the opening.

[0030] Furthermore, a heat dissipation film layer 123 is provided around the lower circuit layer 12, and a heat dissipation through hole 124 communicating with the wiring channel 121 is provided on the heat dissipation film layer 123.

[0031] The heat generated during the operation of the lower circuit layer 12 can be conducted to the outside through the wiring channel 121 and the heat dissipation hole 124. The heat dissipation film layer 123 collects the heat in the circumference of the lower circuit layer 12 to avoid local overheating.

[0032] Specifically, the heat dissipation insulation structure 2 includes heat dissipation layers 21 disposed on the upper and lower sides of the lower circuit layer 12, heat dissipation film layer 123 connected to the heat dissipation layer 21, and an insulation layer 22 disposed between the lower heat dissipation layer 21 and the aluminum sheet 11.

[0033] This configuration creates a continuous heat dissipation path, further dissipating the heat from the heat dissipation film layer 123 and the lower circuit layer 12, thus reducing the overall temperature. An insulating layer 22 blocks the current flow between the aluminum sheet 11 and the heat dissipation layer 21. Furthermore, the insulating layer 22 can be made of a thermally conductive insulating material, allowing the heat from the heat dissipation layer 21 to be indirectly transferred to the aluminum sheet 11, thereby enhancing the heat dissipation effect.

[0034] Furthermore, the upper flexible circuit board assembly 4 includes a PI layer 41, an upper AD adhesive layer 42 is disposed on the upper end of the PI layer 41, and an upper circuit layer 43 is disposed on the side of the upper AD adhesive layer 42 away from the PI layer 41, and a protective film layer 44 is disposed on the surface of the upper circuit layer 43.

[0035] More specifically, the protective film layer 44 includes a plastic film layer that is tightly adhered to the surface of the upper circuit layer 43, and a waterproof and dustproof coating is provided on the upper layer of the plastic film layer.

[0036] Plastic film layer: directly adhered to the surface of the upper circuit layer 43, providing mechanical protection (anti-scratch, anti-squeeze) and preventing the upper circuit layer 43 from being damaged due to physical contact.

[0037] Waterproof and dustproof coating: Covers the plastic film layer to isolate external moisture, dust and other impurities, and prevents the upper circuit layer 43 from failing due to environmental corrosion.

[0038] In detail, the adhesive bonding isolation structure 3 includes a lower AD adhesive layer 31, and a plurality of isolation layers 32 are disposed within the lower AD adhesive layer 31.

[0039] Preferably, an isolation support rubber seat 33 is provided between the isolation layers 32, and an elastic connector 34 is provided on the outside of the isolation layer 32. The elastic connector 34 on the upper side is connected, and the elastic connector 34 on the lower side is connected to the solder resist layer 5.

[0040] The lower AD adhesive layer 31 provides strong adhesion, ensuring a tight connection between the aluminum substrate 1 and the upper flexible board assembly 4, and preventing interlayer separation.

[0041] The isolation layer 32 serves as a physical separator and auxiliary insulation inside the adhesive layer, preventing signal interference between upper and lower circuit layers.

[0042] The isolation support rubber seat 33 is located between the isolation layers 32. It has elasticity and support, and can absorb local stress when the structure is bent or stretched, so as to prevent the lower AD rubber layer 31 from breaking due to stress concentration.

[0043] The elastic connector 34 is connected to the upper flexible board assembly 4 on the upper side and to the solder mask layer 5 on the lower side. When the structure is subjected to tearing force, the elastic connector 34 absorbs the external force through its own elastic deformation, directly blocking the transmission of tearing force to the interlayer connection part, and preventing the aluminum substrate 1 from separating or being damaged from the upper flexible board assembly 4.

[0044] In summary, the principle of this embodiment is as follows: the aluminum sheet 11 provides support and auxiliary heat dissipation; the lower circuit layer 12 realizes the circuit layout through the central wiring channel 121 and the staggered wiring holes 122 on the upper and lower sides; the circumferential heat dissipation film layer 123 and the heat dissipation through holes 124 connecting the wiring channel 121 assist in heat dissipation; the heat dissipation layer 21 of the heat dissipation insulation structure 2 connects to the heat dissipation film layer 123 to enhance heat dissipation; the insulation layer 22 realizes the insulation between the aluminum sheet 11 and the heat dissipation layer 21; the solder resist layer 5 is provided between the lower circuit layer 12 and the adhesive isolation structure 3 to play the role of circuit protection and transition insulation; the adhesive isolation structure 3 realizes the tear-resistant connection between the aluminum substrate 1 and the upper flexible board assembly 4; the upper flexible board assembly 4 realizes flexible circuit and surface protection, thereby achieving the overall effect of rigid support, flexible circuit, tear resistance and efficient heat dissipation.

[0045] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0046] Although this document frequently uses terms such as aluminum substrate 1, aluminum sheet 11, lower circuit layer 12, wiring channel 121, through hole 122, heat dissipation film layer 123, heat dissipation through hole 124, heat dissipation insulation structure 2, heat dissipation layer 21, insulation layer 22, adhesive bonding isolation structure 3, lower AD adhesive layer 31, isolation layer 32, isolation support rubber seat 33, elastic connector 34, upper flexible board assembly 4, PI layer 41, upper AD adhesive layer 42, upper circuit layer 43, protective film layer 44, and solder resist layer 5, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A multi-material circuit board flexible circuit board with tear-resistant design structure, comprising an aluminum sheet (11) disposed on the bottom layer, wherein a lower circuit layer (12) is disposed on the upper end of the aluminum sheet (11), characterized in that, The lower circuit layer (12) is provided with heat dissipation and insulation structure (2) on both the upper and lower sides. The aluminum sheet (11), the lower circuit layer (12) and the heat dissipation and insulation structure (2) together constitute the aluminum substrate (1). The upper layer of the aluminum substrate (1) is connected to the upper flexible board assembly (4) through the adhesive bonding isolation structure (3).

2. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 1, characterized in that, A solder resist layer (5) is provided between the lower circuit layer (12) and the adhesive bonding isolation structure (3).

3. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 2, characterized in that, The lower wiring layer (12) is provided with a horizontally arranged wire passage (121) in the middle, and a number of vertically arranged wire holes (122) are also provided on the lower wiring layer (12) and on both sides of the wire passage (121).

4. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 3, characterized in that, The lower circuit layer (12) is provided with a heat dissipation film layer (123) in the circumferential direction, and the heat dissipation film layer (123) is provided with heat dissipation through holes (124) that are interconnected with the wire channel (121).

5. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 4, characterized in that, The heat dissipation insulation structure (2) includes heat dissipation layers (21) disposed on the upper and lower sides of the lower circuit layer (12), the heat dissipation film layer (123) is connected to the heat dissipation layer (21), and an insulation layer (22) is disposed between the heat dissipation layer (21) on the lower side and the aluminum sheet (11).

6. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 1, characterized in that, The upper flexible board assembly (4) includes a PI layer (41), an upper AD adhesive layer (42) is provided on the upper end of the PI layer (41), and an upper circuit layer (43) is provided on the side of the upper AD adhesive layer (42) away from the PI layer (41), and a protective film layer (44) is provided on the surface of the upper circuit layer (43).

7. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 6, characterized in that, The protective film layer (44) includes a plastic film layer that is tightly attached to the surface of the upper circuit layer (43), and the upper layer of the plastic film layer is provided with a waterproof and dustproof coating.

8. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 2, characterized in that, The adhesive bonding isolation structure (3) includes a lower AD adhesive layer (31), and a plurality of isolation layers (32) are disposed in the lower AD adhesive layer (31).

9. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 8, characterized in that, An isolation support rubber seat (33) is provided between the isolation layers (32), and an elastic connector (34) is provided on the outside of the isolation layer (32). The elastic connector (34) on the upper side is connected, and the elastic connector (34) on the lower side is connected to the solder resist layer (5).

10. The tear-resistant design structure of the multi-material circuit board flexible circuit board according to claim 3, characterized in that, The wire-passing holes (122) are staggered on the upper and lower sides of the wire-passing channel.

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