Soldering groove forming process of a substrate and substrate thereof

Abstract

The application discloses a soldering groove forming process of a substrate and a substrate thereof, and comprises the following steps: performing plasma cleaning on the substrate and drying; selecting a plurality of shielding areas on the surface of the dried substrate, and shielding the areas by using a covering material; performing nickel plating on the upper surface of the substrate, and plating at least one nickel layer; removing the covering material on the substrate surface shielding areas, and forming a plurality of soldering grooves on the surface of the substrate; and performing plasma cleaning on the substrate again, and drying to obtain a finished product. The application can effectively form the soldering grooves, and the formed soldering grooves greatly improve the strength and firmness of the soldering parts.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal plate welding process, in particular to the welding groove forming process of substrate and the substrate thereof. BACKGROUND

[0002] DBC plate is a composite material of copper-ceramic directly combined together, generally in a three-layer structure, the upper and lower two layers are copper layers, and the middle layer is a ceramic layer. The plate has excellent electrical insulation and thermal conductivity characteristics. In the same power semiconductor, the welding type module of the DBC plate has not only small size, light weight, and part saving, but also better thermal fatigue stability and higher integration compared with the ordinary welding type module. Therefore, the current selection of DBC plate as the carrier of the silicon chip of the power module is the development direction in the industry. For example, the Chinese patent with the publication number CN102264504A discloses a manufacturing method of a galvanized metal plate hollow body, which at least includes a first metal plate panel and a second metal plate panel assembled together, the first panel includes a main part perpendicular to parallel end parts connected by a curvature radius, and the method includes at least one laser welding step, during which the first panel is laser welded to the second panel with a predetermined gap. However, the present application has certain deficiencies. In the welding process method, the non-welding surface is not protected to a certain extent, and the welding structure is not stable and firm enough, which may affect the working strength of the component. SUMMARY

[0003] The present application aims to provide a welding groove forming process of substrate and the substrate thereof. The present application can effectively form a welding groove, and the formed welding groove greatly improves the strength and firmness of the welding component.

[0004] The technical solution of the present application is a welding groove forming process of substrate, which includes the following steps:

[0005] S1: plasma cleaning of the substrate, and drying;

[0006] S2: selecting a plurality of shielding areas on the surface of the dried substrate, and shielding with a covering material;

[0007] S3: nickel plating on the upper surface of the substrate, and plating at least one nickel layer;

[0008] S4: removing the covering material of the shielding area on the surface of the substrate, and forming a plurality of welding grooves on the surface of the substrate;

[0009] S5: plasma cleaning of the substrate again, and drying to obtain a finished product.

[0010] In the above welding groove forming process of substrate, the covering material can be glue, wax, or a covering film.

[0011] The shielding area comprises a main shielding area, and side shielding areas are arranged around the main shielding area.

[0012] The soldering groove is in the shape of a cuboid.

[0013] The soldering groove occupies more than half of the area of the substrate.

[0014] The substrate with the soldering groove comprises a plate body, a nickel plating layer arranged on the surface of the plate body, a plurality of soldering grooves arranged on one side of the nickel plating layer, a groove bottom of the soldering groove reaching the surface of the plate body, a mounting hole arranged around the plate body, a short side groove arranged on the short side of the plate body, a long side groove arranged on the long side of the plate body, and a plurality of air outlets arranged on the nickel plating layer and connected with the soldering grooves.

[0015] The soldering groove is in the shape of a cuboid.

[0016] The soldering groove is in the shape of a cylinder.

[0017] The soldering groove is provided with a first side wall, a first cavity arranged on the first side wall, a second side wall arranged on the adjacent side of the first side wall, a second cavity arranged on the second side wall, and a lower opening of the air outlet connected with the first cavity or the second cavity.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1. The present application shields a certain area of the surface of the substrate by using a covering material, so that the area is not provided with the nickel plating layer when the nickel plating is performed, and the covering material is removed after the nickel plating is completed, thereby forming an effective soldering groove, the groove bottom of the soldering groove being the surface of the plate body, and the connecting part of the circuit board being directly soldered with the plate body, so that the connecting strength of each part after soldering is greatly improved, and the performance and service life of the product are ensured.

[0020] 2. The short side groove and the long side groove are arranged to facilitate positioning during the soldering operation.

[0021] 3. The surface of the plate body is provided with the nickel plating layer, and the nickel plating layer does not have the requirement of soldering performance, the nickel plating layer can increase the solder resistance, and prevent the solder from flowing and the DBC from being displaced.

[0022] 4. The welding groove is internally provided with a first side wall, the first side wall is provided with a first cavity, the adjacent side of the first side wall is provided with a second side wall, the second side wall is provided with a second cavity, and the first cavity and the second cavity are filled with solder during welding, thereby increasing the contact area of welding and improving the strength and stability of welding.

[0023] 5. The nickel plating layer is provided with a plurality of air outlets, which are connected with the welding groove. When the solder flows into the welding groove, the air outlets are designed to ensure that the solder can completely fill the entire groove. Due to the existence of the air outlets, the gas in the groove can be discharged, thereby improving the filling capacity of the solder. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a structural schematic diagram of the present application;

[0025] Figure 2 The figure is a structural schematic diagram of the nickel plating layer;

[0026] Figure 3 The figure is an internal schematic diagram of the welding groove;

[0027] Figure 4 The figure is a schematic diagram of the first cavity and the second cavity;

[0028] Figure 5 The figure is a schematic diagram of the air outlet;

[0029] Markings in the drawings: 1-plate body, 3-nickel plating layer, 4-welding groove, 6-first side wall, 7-first cavity, 8-second side wall, 9-second cavity, 10-convex body, 11-air outlet, 101-mounting hole, 102-short side groove, 103-long side groove. DETAILED DESCRIPTION

[0030] The present application will be further described below in combination with the drawings and examples, but it is not used as the basis for limiting the present application.

[0031] Example: The welding groove forming process of the substrate includes the following steps:

[0032] S1: Plasma cleaning of the substrate, drying;

[0033] S2: On the surface of the dried substrate, select a plurality of shielding areas, and shield with a covering material. The covering material can be glue, wax or a covering film. The shielding area includes a main shielding area, and the periphery of the main shielding area is provided with a side shielding area. The thickness of the side shielding area is slightly lower than that of the main shielding area.

[0034] S3: Nickel plating is performed on the upper surface of the substrate, and the nickel plating is performed by electroplating nickel in an electrolyte composed of a nickel salt, a conductive salt, a pH buffer, and a wetting agent. At least one layer of nickel is plated. If a brightener is added to the plating solution, bright nickel is obtained, and if no brightener is added, dark nickel is obtained;

[0035] S4: The covering material of the masking area on the surface of the substrate is removed, and a plurality of solder grooves are formed on the surface of the substrate. The removal of the main masking area forms a solder groove, and the removal of the side masking area forms a chamber. During soldering, the chamber flows into the solder, increases the contact area of the solder, and improves the strength and stability of the solder. The shape of the solder groove is cylindrical, and the shape needs to be designed according to the actual soldering requirements. The area of the solder groove occupies more than half of the total area of the substrate. When the circuit board is soldered to the substrate, a larger soldering area can be ensured to improve the stability of the connection.

[0036] S5: The substrate is subjected to plasma cleaning again, and the finished product is obtained after drying.

[0037] The substrate with a solder groove for realizing the foregoing process is composed of Figure 1 as shown, including a plate body 1, the surface of the plate body 1 is provided with a nickel plating layer 3, and the nickel plating layer is subjected to passivation, sealing and other processes to improve the corrosion resistance of the nickel plating layer, as shown in Figure 2 A plurality of solder grooves 4 are provided on one side of the nickel plating layer 3, and the inside of the solder grooves is pure copper material with better wetting performance to improve the diffusion between the solder and the substrate during the soldering process, form an IMC layer, and reduce the void rate. The solder groove 4 is a cubic groove, and the solder groove 4 is a cylindrical groove. The shape of the solder groove is mainly determined according to the working conditions and requirements of the substrate. The number of solder grooves 4 is three, and the shape of the solder groove is designed according to the actual requirements. The groove bottom of the solder groove 4 reaches the surface of the plate body 1. The plate body is preferably made of pure copper material. The exposed pure copper material in the solder groove has better wetting performance, improves the diffusion between the solder and the substrate during the soldering process, forms an IMC layer, reduces the void rate, and improves the firmness of the soldering. The plate body 1 is provided with mounting holes 101 around the plate body 1, and the plate body 1 is provided with short side grooves 102 on the short side of the plate body 1 and long side grooves 103 on the long side of the plate body 1. When the plate body is subjected to soldering operation, the plate body needs to be fixed, and the long side grooves and the short side grooves can achieve good positioning effect. The nickel plating layer 3 is provided with a plurality of gas outlets 11, the gas outlets 11 are communicated with the solder grooves 4, the solder grooves 4 are provided with first side walls 6, the first side walls 6 are provided with first cavities 7, the adjacent side of the first side walls 6 is provided with second side walls 8, as shown in Figure 4 The second cavity 9 is provided on the second side wall 8, and the lower opening of the gas outlet 11 is communicated with the first cavity 7 or the second cavity 9, as shown in Figure 5As shown, the air outlet hole effectively discharges the air in the cavity, so that the solder can completely fill the cavity. The protrusion 10 is arranged on the nickel plating layer 3 and close to the short side groove, as shown in Figure 3 As shown, during transportation, the plates are stacked, and the protrusion can cause a certain gap between the plate bodies, so as to prevent the nickel plating layer from being scratched.

Claims

1. A process for forming a solder dam for a substrate, characterized by, The substrate comprises a plate body (1), the surface of the plate body (1) is provided with a nickel plating layer (3); a plurality of welding grooves (4) are arranged on the nickel plating layer (3) on one side, the groove bottom of the welding groove (4) reaches the surface of the plate body (1); the periphery of the plate body (1) is provided with a mounting hole (101), the short side of the plate body (1) is provided with a short side groove (102), and the long side of the plate body (1) is provided with a long side groove (103); a plurality of air outlets (11) are arranged on the nickel plating layer (3), and the air outlet (11) is in communication with the welding groove (4); the welding groove (4) is provided with a first side wall (6), the first side wall (6) is provided with a first cavity (7), the adjacent side of the first side wall (6) is provided with a second side wall (8), the second side wall (8) is provided with a second cavity (9), and the lower opening of the air outlet (11) is in communication with the first cavity (7) or the second cavity (9); The welding groove forming process of the substrate comprises the following steps: S1: plasma cleaning the substrate and drying; S2: selecting a plurality of shielding areas on the surface of the dried substrate, and shielding with a covering material; S3: nickel plating on the upper surface of the substrate, and plating at least one nickel layer; S4: removing the covering material of the substrate surface shielding area, and forming a plurality of welding grooves on the surface of the substrate; S5: plasma cleaning the substrate again, and drying to obtain a finished product.

2. The solder slot formation process for a substrate according to claim 1, characterized by: The covering material is glue or wax.

3. The process for forming a solder slot of a substrate according to claim 1, wherein: The shielding area comprises a main shielding area, and the periphery of the main shielding area is provided with a side shielding area.

4. The process for forming a solder slot of a substrate according to claim 1, wherein: The shape of the welding groove is a cubic groove.

5. The process for forming a solder slot of a substrate according to claim 1, wherein: The area of the welding groove occupies more than half of the total area of the substrate.

6. The solder slot formation process for a substrate of claim 1, wherein: The welding groove (4) is a cubic groove.

7. The process of claim 1, wherein: The welding groove (4) is a cylindrical groove.

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