A circuit board structure for improving adhesion of a silver layer

Abstract

This utility model provides a circuit board structure for improving the adhesion of a silver layer, including a substrate. A first copper foil layer, a second copper foil layer, a third copper foil layer, a fourth copper foil layer, and a fifth copper foil layer are printed on the substrate. One end of the first copper foil layer is connected to an annular branch line layer; one end of the second copper foil layer is connected to a first arc-shaped branch line layer; and one end of the third copper foil layer is connected to a second arc-shaped branch line layer. A first low-square carbon resist film layer is printed on the upper surface of the annular branch line layer; a second low-square carbon resist film layer is printed on the upper surface of the first arc-shaped branch line layer; and a third low-square carbon resist film layer is printed on the upper surface of the second arc-shaped branch line layer. A first silver layer is printed on the upper surface of the first low-square carbon resist film layer; a second silver layer is printed on the upper surface of the second low-square carbon resist film layer; and a third silver layer is printed on the upper surface of the third low-square carbon resist film layer. This increases interfacial adhesion, thereby ensuring the quality of the circuit board.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, specifically to a circuit board structure for improving the adhesion of silver layer in a damper controller. Background Technology

[0002] The current general circuit board printing process for damper controllers is as follows: PCB fabrication – acid pickling or water washing of the PCB – silver paste printing and baking – silver paste drying followed by two high-resistivity carbon film printing processes. During normal use, poor adhesion between the silver layer and copper foil easily leads to the overall blocky detachment of the silver-carbon layer, causing potential performance failure. The main reasons for this are as follows: 1. Both silver and copper are metals, and the difference in their coefficients of thermal expansion can lead to interfacial stress accumulation, especially prone to micro-cracks or peeling under temperature changes; 2. The solvent or adhesive in the silver paste has low compatibility with the copper foil surface, reducing wettability and affecting bonding strength; 3. The copper foil surface is smooth and naturally contains an oxide layer, such as Cu2O or CuO, which hinders direct contact between the silver paste and the copper substrate. Some silver paste adhesives lack sufficient affinity for the metal substrate, or excessive shrinkage stress during curing causes the coating to peel off from the edges. In high humidity environments, incompletely cured silver paste is more prone to peeling due to moisture penetration. Given this situation, improvement is urgently needed. Utility Model Content

[0003] To address the above problems, this utility model provides a circuit board structure that improves the adhesion of the silver layer and increases the interfacial bonding force, thereby ensuring the quality of the circuit board.

[0004] To achieve the above objectives, a circuit board structure for improving silver layer adhesion is provided, comprising a substrate on which a first copper foil layer, a second copper foil layer, a third copper foil layer, a fourth copper foil layer, and a fifth copper foil layer are printed. One end of the first copper foil layer is connected to a circular annular branch line layer, one end of the second copper foil layer is connected to a first arc-shaped branch line layer coaxial with the circular annular branch line layer, and one end of the third copper foil layer is connected to a second arc-shaped branch line layer coaxial with the circular annular branch line layer.

[0005] The upper surface of the annular branch layer is printed with a first low-square carbon barrier film layer corresponding to the shape of the annular branch layer, the upper surface of the first arc-shaped branch layer is printed with a second low-square carbon barrier film layer corresponding to the shape of the first arc-shaped branch layer, and the upper surface of the second arc-shaped branch layer is printed with a third low-square carbon barrier film layer corresponding to the shape of the second arc-shaped branch layer.

[0006] A first silver layer corresponding to the shape of the first low-square carbon barrier film is printed on the upper surface of the first low-square carbon barrier film layer; a second silver layer corresponding to the shape of the second low-square carbon barrier film layer is printed on the upper surface of the second low-square carbon barrier film layer; a third silver layer corresponding to the shape of the third low-square carbon barrier film layer is printed on the upper surface of the third low-square carbon barrier film layer; the perimeter of the first silver layer is larger than the perimeter of the first low-square carbon barrier film layer; the perimeter of the second silver layer is larger than the second low-square carbon barrier film layer; the perimeter of the third silver layer is larger than the third low-square carbon barrier film layer.

[0007] A first high-square carbon barrier film layer corresponding to the shape of the first silver layer is printed on the upper surface of the first silver layer; a second high-square carbon barrier film layer is printed on the upper surfaces of the second silver layer and the third silver layer, and between the second silver layer and the third silver layer.

[0008] The upper surface of the first high-square carbon barrier film layer is printed with a third high-square carbon barrier film layer corresponding to the shape of the first high-square carbon barrier film layer; the upper surface of the second high-square carbon barrier film layer is printed with a fourth high-square carbon barrier film layer corresponding to the shape of the second high-square carbon barrier film layer.

[0009] Preferably, the sheet resistance of the first low sheet resistance carbon film layer, the second low sheet resistance carbon film layer, and the third low sheet resistance carbon film layer is set to 10Ω-100Ω.

[0010] Preferably, the perimeter of the first silver layer is 0.05 to 0.1 mm larger than the perimeter of the first low-square carbon barrier film; the perimeter of the second silver layer is 0.05 to 0.1 mm larger than the perimeter of the second low-square carbon barrier film; and the perimeter of the third silver layer is 0.05 to 0.1 mm larger than the perimeter of the third low-square carbon barrier film.

[0011] The beneficial effects of this invention are: by utilizing the strong adhesion between the low sheet resistance carbon film layer and the copper foil, the interface bonding force is effectively increased, thus ensuring the quality of the circuit board. Attached Figure Description

[0012] Figure 1 This is a plan view of the present invention.

[0013] The reference numerals in the attached figures are: substrate 10, annular branch line layer 11, first low square carbon resistive film layer 12, first silver layer 13, second high square carbon resistive film layer 14, first high square carbon resistive film layer 15, fourth high square carbon resistive film layer 16, third high square carbon resistive film layer 17, first arc-shaped branch line layer 18, second arc-shaped branch line layer 19, second copper foil layer 20, first copper foil layer 21, third copper foil layer 22, second low square carbon resistive film layer 23, third low square carbon resistive film layer 24, second silver layer 25, third silver layer 26, fourth copper foil layer 27, and fifth copper foil layer 28. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0015] Reference Figure 1 As shown: A circuit board structure for improving the adhesion of a silver layer includes a substrate 10. A first copper foil layer 21, a second copper foil layer 20, a third copper foil layer 22, a fourth copper foil layer 27, and a fifth copper foil layer 28 are printed on the substrate 10. One end of the first copper foil layer 21 is connected to a circular branch line layer 11. One end of the second copper foil layer 20 is connected to a first arc-shaped branch line layer 18 coaxial with the circular branch line layer 11. One end of the third copper foil layer 22 is connected to a second arc-shaped branch line layer 19 coaxial with the circular branch line layer 11.

[0016] The upper surface of the annular branch line layer 11 is printed with a first low square carbon barrier film layer 12 corresponding to the shape of the annular branch line layer 11, the upper surface of the first arc-shaped branch line layer 18 is printed with a second low square carbon barrier film layer 23 corresponding to the shape of the first arc-shaped branch line layer 18, and the upper surface of the second arc-shaped branch line layer 19 is printed with a third low square carbon barrier film layer 24 corresponding to the shape of the second arc-shaped branch line layer 19.

[0017] The upper surface of the first low-square carbon barrier film layer 12 is printed with a first silver layer 13 corresponding to the shape of the first low-square carbon barrier film layer 12; the upper surface of the second low-square carbon barrier film layer 23 is printed with a second silver layer 25 corresponding to the shape of the second low-square carbon barrier film layer 23; the upper surface of the third low-square carbon barrier film layer 24 is printed with a third silver layer 26 corresponding to the shape of the third low-square carbon barrier film layer 24; the periphery of the first silver layer 13 is larger than the periphery of the first low-square carbon barrier film layer 12; the periphery of the second silver layer 25 is larger than the periphery of the second low-square carbon barrier film layer 23; the periphery of the third silver layer 26 is larger than the periphery of the third low-square carbon barrier film layer 24.

[0018] A first high-square carbon barrier film layer 15 corresponding to the shape of the first silver layer 13 is printed on the upper surface of the first silver layer 13; a second high-square carbon barrier film layer 14 is printed on the upper surface of the second silver layer 25 and the third silver layer 26 and between the second silver layer 25 and the third silver layer 26.

[0019] The upper surface of the first high-square carbon barrier film layer 15 is printed with a third high-square carbon barrier film layer 17 corresponding to the shape of the first high-square carbon barrier film layer 15; the upper surface of the second high-square carbon barrier film layer 14 is printed with a fourth high-square carbon barrier film layer 16 corresponding to the shape of the second high-square carbon barrier film layer 14.

[0020] The sheet resistance of the first low sheet resistance carbon film layer 12, the second low sheet resistance carbon film layer 23, and the third low sheet resistance carbon film layer 24 is set to 10Ω-100Ω.

[0021] The perimeter of the first silver layer 13 is 0.05 to 0.1 mm larger than the perimeter of the first low-square carbon resistive film layer 12; the perimeter of the second silver layer 25 is 0.05 to 0.1 mm larger than the perimeter of the second low-square carbon resistive film layer 23; and the perimeter of the third silver layer 26 is 0.05 to 0.1 mm larger than the perimeter of the third low-square carbon resistive film layer 24.

[0022] In this embodiment, the strong adhesion between the low sheet resistance carbon film and the copper foil is utilized for the transition. The carbon film has low sheet resistance and low contact resistance, which improves adhesion. The principle is as follows:

[0023] 1. Carbon coatings, especially nano-carbon materials, can fill the micro-uneven structure on the surface of copper foil, forming a mechanically interlocked structure. At the same time, the functional groups in carbon materials, such as carboxyl and hydroxyl groups, can form weak chemical bonds with the copper foil oxide layer, such as hydrogen bonds, to enhance the interfacial bonding force.

[0024] 2. Carbon paste has relatively low requirements for the cleanliness of the copper foil surface. Even if there is slight oxidation or contamination, it can still achieve effective adhesion through physical penetration. Its rheological properties also make it easier to cover microscopic defects in the copper foil.

[0025] The above embodiments illustrate only one implementation of this utility model, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A circuit board structure for improving the adhesion of a silver layer, comprising a substrate (10), wherein a first copper foil layer (21), a second copper foil layer (20), a third copper foil layer (22), a fourth copper foil layer (27) and a fifth copper foil layer (28) are printed on the substrate (10), wherein one end of the first copper foil layer (21) is connected to a circular annular branch line layer (11), one end of the second copper foil layer (20) is connected to a first arc-shaped branch line layer (18) coaxial with the circular annular branch line layer (11), and one end of the third copper foil layer (22) is connected to a second arc-shaped branch line layer (19) coaxial with the circular annular branch line layer (11); characterized in that The upper surface of the annular branch line layer (11) is printed with a first low-square carbon barrier film layer (12) corresponding to the shape of the annular branch line layer (11), the upper surface of the first arc-shaped branch line layer (18) is printed with a second low-square carbon barrier film layer (23) corresponding to the shape of the first arc-shaped branch line layer (18), and the upper surface of the second arc-shaped branch line layer (19) is printed with a third low-square carbon barrier film layer (24) corresponding to the shape of the second arc-shaped branch line layer (19). The upper surface of the first low-square carbon barrier film layer (12) is printed with a first silver layer (13) corresponding to the shape of the first low-square carbon barrier film layer (12); the upper surface of the second low-square carbon barrier film layer (23) is printed with a second silver layer (25) corresponding to the shape of the second low-square carbon barrier film layer (23); the upper surface of the third low-square carbon barrier film layer (24) is printed with a third silver layer (26) corresponding to the shape of the third low-square carbon barrier film layer (24); the periphery of the first silver layer (13) is larger than the periphery of the first low-square carbon barrier film layer (12); the periphery of the second silver layer (25) is larger than the second low-square carbon barrier film layer (23); the periphery of the third silver layer (26) is larger than the third low-square carbon barrier film layer (24); A first high-square carbon barrier film layer (15) corresponding to the shape of the first silver layer (13) is printed on the upper surface of the first silver layer (13); a second high-square carbon barrier film layer (14) is printed on the upper surface of the second silver layer (25) and the third silver layer (26) and between the second silver layer (25) and the third silver layer (26); The upper surface of the first high-square carbon barrier film layer (15) is printed with a third high-square carbon barrier film layer (17) corresponding to the shape of the first high-square carbon barrier film layer (15); the upper surface of the second high-square carbon barrier film layer (14) is printed with a fourth high-square carbon barrier film layer (16) corresponding to the shape of the second high-square carbon barrier film layer (14).

2. The circuit board structure according to claim 1, wherein The sheet resistance of the first low sheet resistance carbon film layer (12), the second low sheet resistance carbon film layer (23) and the third low sheet resistance carbon film layer (24) is set to 10Ω-100Ω.

3. The circuit board structure according to claim 1, wherein The perimeter of the first silver layer (13) is 0.05 to 0.1 mm larger than the perimeter of the first low-square carbon barrier film layer (12); the perimeter of the second silver layer (25) is 0.05 to 0.1 mm larger than the perimeter of the second low-square carbon barrier film layer (23); and the perimeter of the third silver layer (26) is 0.05 to 0.1 mm larger than the perimeter of the third low-square carbon barrier film layer (24).

Images