CN112788853A

CN112788853A - Production process of circuit board for increasing area of through hole pad and circuit board

Info

Publication number: CN112788853A
Application number: CN202110027194.4A
Authority: CN
Inventors: 宁娜; 许剑明; 黄军辉; 钟秀霞; 卢龙
Original assignee: Countcash Ltd
Current assignee: Countcash Ltd
Priority date: 2021-01-09
Filing date: 2021-01-09
Publication date: 2021-05-11

Abstract

The application relates to a production process of a circuit board for increasing the area of a pad at a via hole and the circuit board, which comprises the following steps of S1, providing a base material both sides of which are plated with a first plating layer, and simultaneously forming a via hole on the first plating layer and the base material; s2, electroplating a second plating layer on the inner wall of the via hole; s3, filling the liquid resin into the via hole and filling the via hole, S4, electroplating a third plating layer on the side of the first plating layer far away from the substrate; s5, corroding the first plating layer and the third plating layer, forming a circuit on one side of the substrate and the other side of the substrate, and completely washing the chemical film after the corrosion is finished; and S6, coating solder mask ink on the surface of the substrate to form a solder mask ink layer. This application utilizes the third cladding material to seal the opening of second cladding material, has increased the holistic area that pad and component are connected this moment, promotes the joint strength of pad and component.

Description

Production process of circuit board for increasing area of through hole pad and circuit board

Technical Field

The application relates to the technical field of circuit board processing, in particular to a production process of a circuit board for increasing the area of a through hole welding disc and the circuit board.

Background

At present, in order to enable the circuits on two sides of a base material to be communicated in the production process of a circuit board, the circuits on two sides of the base material are generally communicated in a mode of forming a through hole in the base material and plating copper in the through hole, and then a circle of welding disc connected with the circuits is electroplated on the side wall of the through hole of the base material around the through hole, so that the copper in the through hole is not easy to fall off. At the moment, when the element is welded, the element is welded at the through hole in order to increase the welding strength, and the welding area is increased by using the pad electroplated at the through hole, so that the welding strength is increased.

In view of the above-mentioned related art, the inventor believes that when soldering a component, since the opening of the via hole is not closed, the area of the opening of the via hole at the connection position of the line and the component is not connected with the component, and the connection strength of the component and the line is still affected.

Therefore, a new technical solution is needed to solve the above problems.

Disclosure of Invention

In order to increase the connection strength of the element and the circuit board and enable the element not to fall off the circuit board easily, the application provides a circuit board production process for increasing the area of a through hole welding pad.

The application provides a circuit board production technology for increasing area of a via hole welding disk, which adopts the following technical scheme:

a circuit board production process for increasing the area of a pad at a via hole comprises the following steps:

s1, providing a substrate with both sides plated with a first plating layer, and simultaneously forming a via hole on the first plating layer and the substrate;

s2, electroplating a second plating layer on the inner wall of the via hole to connect and conduct the second plating layer with the first plating layers on the two sides of the substrate;

s3, filling the via hole with a liquid resin and filling the via hole with the liquid resin;

s4, forming a plastic part after the resin is solidified, electroplating a third plating layer on one side of the first plating layer, which is far away from the substrate, and covering two ends of the plastic part and the first plating layer by the third plating layer;

s5, corroding the first plating layer and the third plating layer and forming a circuit on one side of the substrate and the other side of the substrate to expose the substrate without the circuit and the pad, wherein the pad is positioned at the through hole, and completely washing off the medicine film after the corrosion is finished;

s6, coating solder resist ink on the surface of the substrate to form a solder resist ink layer, exposing the substrate to cover the solder resist ink layer on one side of the substrate connecting pad, keeping away from the sidewall of the substrate and the sidewall of the pad away from the substrate, and covering the substrate and the circuit with the sweat resist ink layer on one side of the substrate connecting circuit.

By adopting the technical scheme, the opening of the second plating layer is sealed by the third plating layer, the whole area of the connection between the bonding pad and the element is increased, the connection strength between the bonding pad and the element is improved, and the element is not easy to separate from the circuit board and fall off after being welded.

Optionally: and S3, baking the resin to solidify the resin, polishing the solidified plastic part protruding out of the via hole, and enabling two end faces of the plastic part and the side wall of the first plating layer far away from the substrate to be located on the same plane.

Through adopting above-mentioned technical scheme, grind the resin flat before electroplating the third cladding material to make the whole thickness of third cladding material remain stable, make the electroplating process of third cladding material more convenient.

Optionally: in S5, before etching, a chemical film is coated on the side wall of the third plating layer away from the substrate, and then a negative film having the same shape as the shape to be etched is attached to the surface of the chemical film and exposed to form a shape to be etched different from the original color of the chemical film, and then the color-changed chemical film is removed.

By adopting the technical scheme, the position of the corroded first plating layer is determined by the cooperation of the medicine film and the negative film, so that the process of corroding the first plating layer to form a circuit is more convenient.

Optionally: in S6, a gap is left between the solder mask ink layer and the side wall of the pad adjacent to the substrate.

Through adopting above-mentioned technical scheme, when welding component and pad, soldering tin flows into in the clearance between pad and the solder mask printing ink, increases the area of contact of soldering tin and pad this moment, further promotes the joint strength of component.

Optionally: in S5, after the etching is completed, the line and the pad are inspected by AOI.

By adopting the technical scheme, whether the circuit after the corrosion is finished meets the requirement or not is detected, and the generation of inferior-quality products is reduced.

The application still provides a circuit board of increase via hole department pad area, including the substrate, set up in the circuit of substrate one side and set up in the pad of substrate opposite side, the substrate surface runs through there is the via hole, is provided with the connecting piece of being connected with pad and circuit simultaneously in the via hole, the terminal surface that the substrate was kept away from to the connecting piece is in the coplanar with the terminal surface that the substrate was kept away from to the pad, substrate and circuit surface cover have the solder mask printing ink layer simultaneously.

By adopting the technical scheme, the inner cavity of the via hole is filled up through the connecting piece, and meanwhile, the connecting piece is also welded with the element when the element is welded with the welding pad, so that the contact area between the element and a circuit board when the element is welded is increased, and the connection strength of the element is increased.

Optionally: the connecting piece is the cavity setting, the connecting piece inner chamber is provided with the plastic part, the lateral wall of plastic part and the inner chamber laminating of connecting piece.

Through adopting above-mentioned technical scheme, make the connecting piece be the cavity setting, the connecting piece is towards its inner chamber deformation this moment when the connecting piece produces expend with heat and contract with cold, and its whole appearance is difficult for producing great change when expend with heat and contract with cold to make the difficult production of via hole cracked, make the use of circuit board remain stable.

Optionally: and a gap is reserved between the welding-proof ink layer and the side wall of the welding disc adjacent to the base material.

By adopting the technical scheme, when the element is welded with the pad, the soldering tin for welding can flow into the space between the pad and the anti-welding ink layer, so that the contact area between the soldering tin and the pad is increased, the soldering tin after welding is not easy to separate from the pad, and the connection strength of the element connected with the soldering tin is increased.

Drawings

FIG. 1 is a flow chart of an embodiment of the present application;

FIG. 2 is a schematic diagram of an embodiment of the present application for illustrating the step S1;

FIG. 3 is a schematic diagram of an embodiment of the present application for illustrating the step S2;

FIG. 4 is a schematic diagram of an embodiment of the present application for illustrating the step S3;

FIG. 5 is a schematic diagram of an embodiment of the present application for illustrating the step S4;

FIG. 6 is a schematic diagram of an embodiment of the present application for illustrating the step S5;

FIG. 7 is a schematic diagram of an embodiment of the present application for illustrating the step S6;

fig. 8 is a schematic diagram for showing a circuit board structure according to an embodiment of the present application.

In the figure, 1, a substrate; 11. a via hole; 2. a first plating layer; 3. a second plating layer; 4. a third plating layer; 5. a line; 6. a pad; 7. a plastic part; 8. a connecting member; 9. a solder mask ink layer; 10. coating with a medicinal film; 12. negative film.

Detailed Description

The present application is described in further detail below with reference to the attached drawings.

The application discloses a production process of a circuit board for increasing the area of a pad at a via hole, which increases the connection strength of the pad 6 and a component after the pad is welded with the component.

As shown in fig. 1, the method comprises the following steps:

s1, as shown in fig. 2, providing a substrate 1 with first plating layers 2 plated on both sides, and forming a via hole 11 in the first plating layer and the substrate 1;

s2, as shown in fig. 3, electroplating the second plating layer 3 on the inner wall of the via hole 11, so that the second plating layer 3 is connected and conducted with the first plating layer 2 on both sides of the substrate 1, and two end surfaces of the second plating layer 3 are respectively on the same plane with the side wall of the first plating layer 2 away from the substrate 1;

s3, as shown in fig. 4, filling the via hole 11 with a heated and melted resin which is the same as the material of the substrate 1 and fills the via hole 11, baking the resin to solidify the resin to form a plastic part 7 protruding out of the via hole 11, and then polishing the plastic part 7 solidified and protruding out of the via hole 11 to make two end surfaces of the plastic part 7 and the sidewall of the first plating layer 2 away from the substrate 1 respectively in the same plane;

s4, as shown in fig. 5, electroplating a third plating layer 4 on a side of the first plating layer away from the substrate 1, where the third plating layer 4 covers the plastic part 7 and the first plating layer 2, and the thickness of the third plating layer 4 is equal to that of the first plating layer 2;

s5, as shown in fig. 6, coating a drug film 10 on the side wall of the third plating layer 4 far from the substrate 1, then adhering a negative film 12 having the same shape as that to be etched to the surface of the drug film 10 and exposing the film to form a shape to be etched on the drug film 10, which is different from the original color of the drug film 10, and then washing off the drug film 10 having a changed color, then etching the parts of the first plating layer 2 and the third plating layer 4 not covered by the drug film 10 and forming a circuit 5 on one side of the substrate 1 on the other side of the pad 6 to expose the substrate 1 without the circuit 5 and the pad 6, the pad 6 and the via hole 11 being coaxially arranged, and washing off the drug film 10 after the etching is completed;

s6, as shown in fig. 7, the surface of the substrate 1 is coated with solder mask ink to form a solder mask ink layer 9, the solder mask ink layer 9 on the side of the bonding pad 6 of the substrate 1 partially covers the exposed surface of the substrate 1, a gap is left between the solder mask ink layer 9 and the side wall of the bonding pad 6 adjacent to the substrate 1, and the solder mask ink layer on the side of the connecting line 5 of the substrate 1 completely covers the substrate 1 and the circuit 5.

The opening formed by the second plating layer 3 is closed by the third plating layer 4, so that the contact area between the element and the pad 6 is increased by the third plating layer 4 in the process of welding the element, and the connection strength between the pad 6 and the element is increased. Leave the clearance between anti-welding ink layer 9 and the pad 6, when component and pad 6 welding this moment, soldering tin flows into between pad 6 and the anti-welding ink layer 9, further increases the area of contact of component and pad 6, is difficult for contacting between soldering tin and the winter protection printing ink simultaneously, and the border position of soldering tin and by the difficult clearance that appears of welded junction this moment have further promoted the joint strength of component and pad 6. The via holes 11 are filled with resin, so that gaps in the via holes 11 are not filled, the inner cavities of the via holes 11 are supported, the structure of the via holes 11 of the circuit 5 board is not easy to damage, and the stability of the circuit 5 board in the using process is improved.

The utility model provides an increase circuit board of via hole department pad area, as shown in fig. 8, includes substrate 1, sets up in the copper circuit 5 of substrate 1 one side and sets up in the copper pad 6 of substrate 1 opposite side, and substrate 1 is the resin material, and its surface runs through has a plurality of via holes 11, is provided with in the via hole 11 simultaneously with pad 6 and circuit 5 be connected and the connecting piece 8 that switches on, and connecting piece 8 is the copper. The gap in the via hole 11 is filled by the connecting piece 8, and at the moment, the element is directly welded with the connecting piece 8 and the bonding pad 6 in the welding process, so that the contact area of the element during welding is increased, and the element is more stably connected.

As shown in fig. 8, when the whole connecting member 8 is made of copper, it is easy to cause the via hole 11 to be broken when expanding with heat and contracting with cold, so the connecting member 8 is hollow, the inner cavity of the connecting member is provided with the plastic member 7, the plastic member 7 is made of resin, and the side wall of the plastic member 7 is attached to the inner wall of the connecting member 8. Utilize the clearance that 8 inner chambers of connecting piece set up to make connecting piece 8 shrink towards its inner chamber when expend with heat and contract with cold this moment to be difficult for influencing via hole 11's structure, thereby make the use of 5 boards of circuit remain stable.

As shown in fig. 8, the surfaces of the substrate 1 and the circuit 5 are coated with the anti-welding ink layer 9, a gap is left between the anti-welding ink layer 9 and the side wall of the pad 6 adjacent to the substrate 1, at this time, when the component is welded to the pad 6, the soldering tin flows into the side wall of the pad 6 adjacent to the substrate 1, so that the contact area between the pad 6 and the component is increased, meanwhile, the edge of the soldering tin does not generate a gap between the soldering tin and the joint due to the contact with the anti-welding ink layer 9, the connection strength of the soldering tin is further increased, and the connection of the component is more stable.

The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides an increase circuit board production technology of via hole department pad area which characterized in that: the method comprises the following steps:

s1, providing a substrate (1) with both sides plated with first plating layers (2), and simultaneously forming a through hole (11) on the first plating layers (2) and the substrate (1);

s2, electroplating a second plating layer (3) on the inner wall of the via hole (11) to connect and conduct the second plating layer (3) with the first plating layers (2) on the two sides of the substrate (1);

s3, filling liquid resin into the via hole (11) to form and fill the via hole (11);

s4, forming a plastic part (7) after the resin is solidified, electroplating a third plating layer (4) on one side of the first plating layer (2) far away from the substrate (1), and covering two ends of the plastic part (7) and the first plating layer (2) by the third plating layer (4);

s5, corroding the first plating layer (2) and the third plating layer (4), forming a pad (6) on one side of the substrate (1), and forming a circuit (5) on the other side of the pad (6), exposing the substrate (1) without the circuit (5) and the pad (6), wherein the pad (6) is positioned at the via hole (11), and completely washing off the medicine film (10) after the corrosion is finished;

s6, coating anti-welding ink on the surface of the substrate (1) to form an anti-welding ink layer (9), exposing the substrate (1) to cover the exposed part of the anti-welding ink layer (9) positioned on one side of the connecting pad (6) of the substrate (1), enabling the side wall of the anti-welding ink layer (9) far away from the substrate (1) to be flush with the side wall of the connecting pad (6) far away from the substrate (1), and enabling the anti-welding ink layer (9) positioned on one side of the connecting line (5) of the substrate (1) to cover the substrate (1) and the line (5).

2. The process of claim 1, wherein the area of the via pad is increased by: and S3, baking the resin to solidify the resin, polishing the solidified plastic part (7) protruding out of the via hole (11), and enabling two end faces of the plastic part (7) to be located on the same plane with the side wall, far away from the substrate (1), of the first plating layer (2) respectively.

3. The process of claim 1, wherein the area of the via pad is increased by: in the step S5, before etching, the side wall of the third plating layer (4) far away from the base material (1) is coated with the medicine film (10), then the negative film (12) with the same shape as the shape needing etching is pasted on the surface of the medicine film (10) and is exposed, so that the shape needing etching and different from the original color of the medicine film (10) is formed on the medicine film (10), and then the medicine film (10) with the changed color is removed.

4. The process of claim 1, wherein the area of the via pad is increased by: in the step S6, a gap is left between the welding-proof ink layer (9) and the side wall of the pad (6) adjacent to the substrate.

5. The process of claim 3, wherein the area of the via pad is increased by: in S5, after the etching is completed, the line (5) and the pad (6) are inspected by AOI.

6. The utility model provides an increase circuit board of via hole department pad area which characterized in that: including substrate (1), set up in circuit (5) of substrate (1) one side and set up in pad (6) of substrate (1) opposite side, substrate (1) surface runs through there is via hole (11), is provided with connecting piece (8) of being connected with pad (6) and circuit (5) simultaneously in via hole (11), the terminal surface that substrate (1) was kept away from in connecting piece (8) and pad (6) are kept away from the terminal surface of substrate (1) and are in the coplanar, substrate (1) and circuit (5) surface cover simultaneously have prevents welding printing ink layer (9).

7. The circuit board of claim 6, wherein the area of the pad at the via hole is increased by: the connecting piece (8) is a hollow arrangement, the inner cavity of the connecting piece (8) is provided with a plastic part (7), and the side wall of the plastic part (7) is attached to the inner cavity of the connecting piece (8).

8. The circuit board of claim 7, wherein the area of the pad at the via hole is increased by: and a gap is reserved between the welding-proof ink layer (9) and the side wall of the welding pad (6) adjacent to the base material (1).