Printed circuit board capable of preventing short circuit caused by oil leakage of carbon oil

Abstract

The utility model discloses a printed circuit board capable of preventing short circuit caused by carbon oil leakage, and the printed circuit board can better enable a circuit layer in a non-welding area on a substrate to maintain a good insulation effect and prevent short circuit through a first solder mask layer and a second solder mask layer which are stacked on the substrate, and also can improve the mechanical strength and moisture resistance. Besides, a first solder mask window and a second solder mask window are formed by the first solder mask layer and the second solder mask layer at the carbon oil key position, so that a stepped solder mask window is formed at the periphery of the conduction circuit at the carbon oil key position, and then a carbon oil layer formed at the solder mask window through silk screen can better cover and solidify on the conduction circuit. Moreover, in the process that the carbon oil of the carbon oil layer is screen-printed in the stepped solder resist window formed by the first solder resist window and the second solder resist window, due to the special structure of the stepped solder resist window, the carbon oil of the carbon oil layer can be better attached to the interior of the solder resist window and is not prone to diffusion, and short circuit between adjacent carbon oil lines is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit board manufacturing, and in particular to a printed circuit board capable of preventing carbon oil from seeping in and causing short circuits. Background Art

[0002] In the modern electronics manufacturing industry, as electronic products become increasingly intelligent, miniaturized, and integrated, printed circuit boards (PCBs), core components of these products, are experiencing continuous advancements in design and manufacturing technology. Among these technologies, screen printing carbon ink technology, a method for directly forming a conductive carbon film on a PCB to replace traditional resistors, has been widely used in applications such as TV remote controls, telephones, children's toys, and computers, significantly reducing component count, lowering production costs, and improving assembly efficiency. Traditional screen printing primarily identifies component locations, functional descriptions, and provides visual guidance on PCBs. Carbon ink screen printing adds both conductivity and protection. Carbon ink, with its excellent conductivity and oxidation resistance, not only effectively replaces resistors but also provides a degree of protection from environmental factors. However, during high-density PCB manufacturing, the spacing between adjacent carbon ink lines is shrinking. Due to the fluidity of carbon ink, it easily diffuses during high-temperature curing, leading to oil seepage. This can cause short circuits between carbon ink lines, seriously impacting the electrical performance and reliability of the PCB. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this application is to provide a printed circuit board that prevents carbon oil leakage and short circuit, so as to solve the problems raised in the above background technology.

[0004] According to one aspect of the present application, a printed circuit board for preventing carbon oil from seeping and short-circuiting includes a substrate, a circuit layer, a first solder resist layer, a second solder resist layer and a carbon oil layer, wherein the substrate is provided with a circuit layer, and a carbon oil key position requiring screen printing carbon oil is provided on the circuit layer, and the circuit layer located at the carbon oil key position is a conductive circuit, and a first solder resist layer is provided on the substrate to cooperate with the circuit layer, and at least one first solder resist window is formed in the first solder resist layer corresponding to the conductive circuit at the carbon oil key position, and the first solder resist layer is provided with a first solder resist window. A second solder resist layer is provided in combination with the circuit layer, and at least one second solder resist window is formed in the second solder resist layer corresponding to the conductive circuit at the carbon oil key position. The size of the second solder resist window is larger than the size of the first solder resist window. A carbon oil layer is provided above the conductive circuit, and the carbon oil layer completely covers the first solder resist window and the second solder resist window. A gap is left between adjacent carbon oil circuits of the carbon oil layer, and the first solder resist layer and the second solder resist layer located between adjacent carbon oil circuits of the carbon oil layer form a solder resist bridge.

[0005] Preferably, the distance between one side of the first solder resist window and the corresponding one side of the conductive line is at least 3 mils, and the distance between one side of the second solder resist window and the corresponding one side of the first solder resist window is less than or equal to 2 mils.

[0006] Preferably, the spacing between a single side of the carbon oil circuit of the carbon oil layer and a corresponding single side of the second solder resist window is less than or equal to 2 mil.

[0007] Preferably, the spacing between adjacent carbon oil lines in the carbon oil layer is greater than or equal to 14 mil.

[0008] Preferably, the carbon oil layer adopts 100T / cm 2 Steel screen printing.

[0009] Preferably, the carbon oil layer has a thickness of 15-35 μm.

[0010] Preferably, the first solder resist layer and the second solder resist layer are both made of 36T / cm 2 Screen printing.

[0011] Preferably, the thickness of the first solder resist layer and the second solder resist layer are both 5-15 μm.

[0012] The advantages of the present application over the prior art are as follows: a printed circuit board for preventing carbon oil leakage and short circuit in the present application can better maintain a good insulation effect of the circuit layer in the non-welding area of ​​the substrate by stacking the first solder resist layer and the second solder resist layer on the substrate, thereby preventing short circuit and increasing mechanical strength and moisture resistance; in addition, the first solder resist window and the second solder resist window are arranged at the carbon oil key position, and the size of the second solder resist window is larger than the size of the first solder resist window, so that a step is formed on the side of the conductive circuit at the carbon oil key position. The ladder-shaped solder resist windows enable the carbon oil layer formed by silk-screening at the solder resist windows to better cover and solidify on the conductive circuit, and in the process of silk-screening the carbon oil in the stepped solder resist windows formed by the first solder resist windows and the second solder resist windows, due to the special structure of the stepped solder resist windows, the carbon oil in the carbon oil layer can better adhere to the solder resist windows and the surface tension of the carbon oil in the carbon oil layer makes it difficult to diffuse, thereby avoiding short circuits between adjacent carbon oil lines; and the double-layer setting of the solder resist bridge between adjacent carbon oil lines in the carbon oil layer can better avoid carbon oil short circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic diagram of a carbon oil key structure of a printed circuit board that prevents carbon oil leakage and short circuit according to an embodiment of the present application.

[0014] Figure 2 This is a schematic diagram of a slice structure of a printed circuit board without screen-printed carbon oil for preventing carbon oil leakage and short circuit according to an embodiment of the present application.

[0015] Figure 3 This is a schematic diagram of the slicing structure of a printed circuit board after screen printing carbon oil to prevent carbon oil leakage and short circuit according to an embodiment of the present application.

[0016] Figure numerals: 1, substrate; 2, circuit layer; 201, conducting circuit; 3, first solder resist layer; 301, first solder resist window; 4, second solder resist layer; 401, second solder resist window; 5, carbon oil layer; 6, carbon oil key position. DETAILED DESCRIPTION

[0017] In order to make the content of this application easier to understand, the technical solutions in the embodiments of this application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of this application. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the attached drawings. Figure 3 In the present invention, the terms "inner" and "outer" refer to directions toward or away from the geometric center of a particular component, respectively. In addition, the terms "first", "second", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0018] like Figures 1 to 3 As shown, a printed circuit board for preventing carbon oil from seeping and short circuit includes a substrate 1, a circuit layer 2, a first solder resist layer 3, a second solder resist layer 4 and a carbon oil layer 5. The circuit layer 2 is provided on the substrate 1, and a carbon oil key position 6 requiring screen printing of carbon oil is provided on the circuit layer 2. The circuit layer 2 located at the carbon oil key position 6 is a conducting circuit 201. The first solder resist layer 3 is provided on the substrate 1 in conjunction with the circuit layer 2, and the second solder resist layer 4 is provided on the first solder resist layer 3 in conjunction with the circuit layer 2. In the design, by stacking the first solder resist layer 3 and the second solder resist layer 4 on the substrate 1, the circuit layer 2 in the non-welding area on the substrate 1 can better maintain a good insulation effect, prevent short circuit, and also increase mechanical strength and moisture resistance. Specifically, the first solder resist layer 3 and the second solder resist layer 4 are both made of 36T / cm 2 Screen printing, using 36T / cm 2 The screen printing can improve the ink passing rate, meet the demand for the amount of ink applied to the first and second solder resist inks during the processing, effectively reduce screen printing bubbles, and optimize the solvent and detergent resistance of the solder resist film formed by the first solder resist layer 3 and the second solder resist layer 4, so as to avoid the poor solvent and detergent resistance of the solder resist film, resulting in rough surface, swelling, stickiness, blistering and color change of the circuit board; in addition, the thickness of the first solder resist layer 3 and the second solder resist layer 4 are both 10μm to ensure that the total thickness of the first solder resist layer 3 and the second solder resist layer 4 after lamination is moderate, so as to avoid the solder resist layer being too thick, which will increase the volume of the circuit board and reduce the thermal conductivity.

[0019] When processing a printed circuit board, at least one first solder resist window 301 is formed by the first solder resist layer 3 arranged around the carbon oil key position 6 corresponding to the conductive line 201, and the size of the first solder resist window 301 is not less than the line width of the conductive line 201 at the carbon oil key position 6, and at least one second solder resist window 401 is formed by the second solder resist layer 4 arranged around the carbon oil key position 6 corresponding to the conductive line 201, and the size of the second solder resist window 401 is larger than the size of the first solder resist window 301, and the conductive line A carbon oil layer 5 is provided above the circuit 201, and the carbon oil layer 5 completely covers the first solder resist window 301 and the second solder resist window 401. In this design, the first solder resist window 301 and the second solder resist window 401 formed by the first solder resist layer 3 and the second solder resist layer 4 at the carbon oil key position 6, and the setting that the size of the second solder resist window 401 is larger than the size of the first solder resist window 301, so that a stepped solder resist window is formed around the conductive circuit 201 at the carbon oil key position 6. , thereby making the carbon oil layer 5 formed by silk-screening at the solder resist window better cover and solidify on the conductive line 201, and in the process of silk-screening the carbon oil in the carbon oil layer 5 in the stepped solder resist window formed by the first solder resist window 301 and the second solder resist window 401, due to the special structure of the stepped solder resist window, thereby making the carbon oil in the carbon oil layer 5 better adhere to the solder resist window and the surface tension of the carbon oil in the carbon oil layer 5 makes it difficult to diffuse, thereby avoiding short circuits between adjacent carbon oil lines; specifically, the distance between the single side of the first solder resist window 301 and the corresponding single side of the conductive line 201 is 3 mil, and the single side of the second solder resist window 401 is 1 mil wider than the corresponding single side of the first solder resist window 301, thereby making the first solder resist window 301 and the second solder resist window 401 can form stepped solder resist windows, and can avoid the solder resist windows being too large, resulting in poor welding, short circuit and affecting the overall performance of the circuit board; in addition, the carbon oil layer 5 adopts 100T / cm 2 Steel screen printing, 100T / cm 2Steel mesh has the following advantages: high tension, the tension value is much higher than the polyester mesh commonly used in screen printing carbon oil, and the tension stability is high; ultra-high precision, uniform wire diameter and opening, and extremely small error rate; low elongation, under high tension, the stretching degree of the screen is very small; high yield point, under extremely high tension, the screen will not lose elasticity due to deformation; high wear resistance, the wear resistance of steel wire is excellent, far exceeding that of fiber; no static electricity, prevent static electricity from affecting printing and ensure printing effect; good heat resistance, suitable for hot melt ink, which is a special advantage of steel mesh; good solvent resistance, prevent various solvents from damaging the screen, Ensure printing security; in addition, the thickness of the carbon oil layer 5 is 25μm. By controlling the thickness of the carbon oil layer 5, the carbon oil layer 5 is evenly adhered, and then the resistance of the carbon film formed by the carbon oil layer 5 is controlled to optimize the silk screen efficiency, and the thickness of the carbon oil layer 5 is higher than the thickness of the stepped solder resist window, and the single-side spacing between the carbon oil line of the carbon oil layer 5 and the corresponding second solder resist window 401 is 1mil. This setting can not only make the carbon oil layer 5 completely cover the stepped solder resist window to prevent the line at the solder resist window from coming into contact with the outside air and causing oxidation, but also avoid the carbon oil layer 5. The spacing between adjacent carbon oil lines is too small to cause a short circuit.

[0020] There is a gap between adjacent carbon oil lines of the carbon oil layer 5, and the spacing between adjacent carbon oil lines of the carbon oil layer 5 is 16 mil. The first solder resist layer 3 and the second solder resist layer 4 located between the adjacent carbon oil lines of the carbon oil layer 5 form a solder resist bridge. In this design, the solder resist bridge between the adjacent carbon oil lines of the carbon oil layer 5 is a double-layer setting, which can better avoid carbon oil short circuit.

[0021] The above embodiments are intended only to illustrate the technical solutions of the embodiments of the present application and are not intended to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that, without departing from the spirit and scope defined by the claims of the present application, they may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents.

Claims

1. A printed circuit board that prevents carbon oil from leaking and short-circuiting, characterized in that: The invention comprises a substrate (1), a circuit layer (2), a first solder resist layer (3), a second solder resist layer (4) and a carbon oil layer (5); the circuit layer (2) is provided on the substrate (1); a carbon oil key position (6) requiring screen printing carbon oil is provided on the circuit layer (2); the circuit layer (2) located at the carbon oil key position (6) is a conducting circuit (201); the substrate (1) is provided with a first solder resist layer (3) in coordination with the circuit layer (2); the first solder resist layer (3) is provided around the carbon oil key position (6) corresponding to the conducting circuit (201) to form at least one first solder resist window (301); the first solder resist layer (3) is provided in coordination with the circuit layer (2); The invention relates to a method for manufacturing a conductive circuit (201) comprising: firstly, a conductive circuit (201) and a conductive circuit (201) provided with a plurality of solder resist layers (4), wherein the second solder resist layer (4) is arranged around the carbon oil key position (6) and corresponds to the conductive circuit (201) to form at least one second solder resist window (401), wherein the size of the second solder resist window (401) is larger than the size of the first solder resist window (301), and the conductive circuit (201) is provided with a carbon oil layer (5), and the carbon oil layer (5) completely covers the first solder resist window (301) and the second solder resist window (401), and a gap is left between adjacent carbon oil circuits of the carbon oil layer (5), and the first solder resist layer (3) and the second solder resist layer (4) located between adjacent carbon oil circuits of the carbon oil layer (5) form a solder resist bridge.

2. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The first solder resist window (301) is at least 3 mils away from a single side of the conductive line (201), and the second solder resist window (401) is less than or equal to 2 mils away from a single side of the first solder resist window (301).

3. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The distance between a single side of the carbon oil circuit of the carbon oil layer (5) and the corresponding second solder resist window (401) is less than or equal to 2 mil.

4. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The spacing between adjacent carbon oil lines in the carbon oil layer (5) is greater than or equal to 14 mil.

5. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The carbon oil layer (5) adopts 100T / cm 2 Steel screen printing.

6. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The carbon oil layer (5) has a thickness of 15-35 μm.

7. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The first solder resist layer (3) and the second solder resist layer (4) both adopt 36T / cm 2 Screen printing.

8. A printed circuit board for preventing carbon oil leakage and short circuit according to claim 1, characterized in that: The thickness of the first solder resist layer (3) and the second solder resist layer (4) are both 5-15 μm.

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