High-frequency substrate soft soldering resistance welding method

Abstract

According to the high-frequency substrate soft soldering resistance welding method, the silicone rubber is arranged on the edge of the high-frequency substrate, the brazing filler metal is blocked, and the situation of overflowing at the non-welding position is greatly improved. Therefore, the problem that in the prior art, overflowing brazing filler metal is treated is solved. Therefore, full-process automatic processing of the high-frequency substrate is realized, and manual intervention is reduced. In addition, by preventing the brazing filler metal from overflowing, the situation that non-welding parts are manually treated is avoided, the integrity of the non-welding parts is guaranteed, damage to the cavity is avoided, and the product quality is improved.

Description

Technical Field

[0001] The present application relates to the technical field of substrate welding, and in particular to a high-frequency substrate soft soldering and solder resistance method. Background Art

[0002] High-frequency substrates are the main carriers of microwave product signal transmission. The industry often uses soft soldering to install high-frequency substrates in product cavities to achieve good heat dissipation and grounding performance. The process flow of high-frequency substrate soft soldering is: first pre-place solder between the high-frequency substrate and the bottom of the cavity, and then use tooling to press the solder, the high-frequency substrate, and the cavity welding surface into contact (such as Figure 1 ), and then heated in a furnace to melt the solder and form a metallurgical bond with the substrate and cavity welding surface. The back of the high-frequency substrate and the bottom of the cavity are coated with a solderable coating.

[0003] During the welding process, the molten solder will wet and spread along the surface of the coating. Since the bottom surface of the product cavity is usually plated on the entire surface, during the welding reaction stage, the solder will wet and spread along the surface of the coating, overflowing the welding surface of the substrate and flowing to other non-welding areas (such as Figure 2 As shown in the figure, it affects the assembly of non-welding parts and requires a lot of time to manually clean the overflowed excess solder after welding, which not only affects the production efficiency, but also may cause product damage.

[0004] Therefore, a high-frequency substrate soldering resist method is urgently needed. Summary of the invention

[0005] The purpose of the present application is to provide a high-frequency substrate soft soldering resist method to solve the problems of assembly difficulties and product damage caused by solder overflow during the existing high-frequency substrate welding process.

[0006] A high-frequency substrate soldering resist method, the method is applied to the production of products containing a high-frequency substrate and a cavity, the method comprising:

[0007] Apply solder to the preset welding area in the cavity, place the high-frequency substrate on the solder by using a tool, and apply a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, so that a closed space is formed between the high-frequency substrate and the cavity, and the solder is sealed in the closed space;

[0008] Placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber;

[0009] Placing the solidified silicone rubber product in a heating furnace so that the high-frequency substrate is fixed on the cavity through the solder;

[0010] Apply the corresponding solvent to the solidified silicone rubber and remove the silicone rubber.

[0011] Furthermore, before applying a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, and then placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber, the method further includes:

[0012] The product is subjected to a vacuum treatment so that the silicone rubber is in full contact with the surface of the cavity coating.

[0013] Furthermore, the vacuum degree in the vacuum treatment is: ≤0.1 bar, and the time is: 1 to 3 minutes.

[0014] Furthermore, the silicone rubber is GD414 silicone rubber.

[0015] Furthermore, the humidity in the constant temperature and humidity cabinet is set to be greater than 90%, and the temperature is set to be 80°C±5%.

[0016] Furthermore, the corresponding solvent applied on the silicone rubber is anhydrous ethanol.

[0017] Furthermore, the cavity is rectangular, a rectangular groove is provided in the middle, and a welding coating is provided at the bottom of the rectangular groove.

[0018] Furthermore, the high-frequency substrate is in the shape of a rectangular thin plate, and a welding plating layer is provided on the bottom.

[0019] Furthermore, the material of the welding plating layer is copper.

[0020] Furthermore, the inner diameter of the needle of the dispensing device is 0.51 mm and the outer diameter is 0.82 mm.

[0021] The beneficial effects of the present invention are as follows:

[0022] The present invention provides a high-frequency substrate soldering resist method, which blocks the solder by setting silicone rubber on the edge of the high-frequency substrate, greatly improving the overflow of the non-welding part. Thus, the process of handling the overflowed solder in the prior art is strengthened. Thus, the full process automation of the high-frequency substrate is realized, reducing manual intervention.

[0023] In addition, by preventing the solder from overflowing, manual processing of non-welding parts is avoided, the integrity of non-welding parts is guaranteed, damage to the cavity is avoided, and the quality of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the installation structure of a high-frequency substrate soft soldering solder resist method;

[0025] Figure 2 It is a schematic diagram of solder overflow during the soldering process of a high-frequency substrate soft soldering solder resist method;

[0026] Figure 3 It is a schematic diagram of pre-coating silicone rubber on the edge of a high-frequency substrate in a method for soldering a high-frequency substrate with solder resist;

[0027] Figure 4 It is one of the flow charts of a method for soldering and resisting soldering of a high-frequency substrate;

[0028] Figure 5 The present invention is one of the flow charts of a method for soldering and resisting soldering of a high-frequency substrate. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this specification clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and their corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this document.

[0030] The following combination Figure 1-5 , describes in detail the technical solutions provided by each embodiment of this specification. Specific embodiment 1:

[0032] The present invention discloses a high-frequency substrate brazing and soldering method, the main process is as follows: Figure 4 shown.

[0033] 1Install the base plate: Follow Figure 1 The method shown will be for baseplate mounting.

[0034] 2 Pre-coating silicone rubber: Use a dispensing device or dispensing station to evenly apply a layer of GD414 silicone rubber (such as Figure 3 As shown), the dispensing needle is 21G (inner diameter: 0.51mm, outer diameter: 0.82mm).

[0035] 3. Vacuum treatment: Vacuum the product to remove the bubbles in the glue and make the glue fully contact with the surface of the cavity coating. The vacuum degree is ≤0.1bar and the time is 1 to 3min.

[0036] 4 Constant temperature and humidity treatment: Place the product coated with silicone rubber in a constant temperature and humidity cabinet to allow the glue to solidify quickly, maintaining time: 2h±10%, humidity: ≥90%, temperature: 80℃±5%.

[0037] 5. Substrate brazing: Place the product completed in 4 in the brazing furnace and Figure 5In the process shown, the furnace chamber first heats up naturally at a rate of 1-2°C / s. Then the temperature is uniformed at a rate not exceeding 1°C / s to fully preheat the product and solder. Then the furnace chamber is rapidly heated at 3-4°C / s to reach the peak temperature. At the peak temperature, the solder melts, and the molten solder reacts with the high-frequency substrate and the cavity surface coating to form intermetallic compounds. The reaction lasts for 30s to 90s. Finally, the furnace chamber is rapidly cooled at a rate not less than 3°C / s, and the solder solidifies to form a connection between the high-frequency substrate and the product cavity.

[0038] 6. Remove the film: first use a cotton swab dipped in anhydrous ethanol to wipe the silicone rubber repeatedly 2 to 3 times, and then tear off the film.

[0039] The key points of the present invention are:

[0040] 1) Use silicone rubber for solder mask protection. This kind of glue can easily form good contact with the coating surface and prevent the solder from spreading and wetting. In addition, this kind of glue can withstand higher soldering temperatures and will not change in quality and produce excess materials that affect product quality.

[0041] 2) The silicone rubber is pre-treated by vacuuming to make the rubber fully contact with the coating surface and improve the barrier effect. The constant temperature and humidity maintenance method is used to accelerate the solidification of the rubber.

[0042] 3) After brazing, use anhydrous ethanol wiping method to reduce the bonding force between the silicone rubber and the cavity, so that the film can fall off as a whole.

[0043] The present invention has the following advantages or effects

[0044] (1) Good solder resistance effect

[0045] This method is used to block the wetting of the solder, which greatly improves the flow condition in non-welding areas.

[0046] (ii) Simple operation

[0047] Using common silicone rubber, the pre-coating and post-welding debonding processes are simple and easy.

[0048] (III) Small product impact

[0049] The coating is blocked to prevent the solder from contacting and reacting with the coating in non-welding areas. After the substrate is brazed, the adhesive film can be completely removed without any residual harmful substances or other adverse effects on the product. Specific embodiment 2:

[0051] The purpose of the present application is to provide a high-frequency substrate soft soldering resist method to solve the problems of assembly difficulties and product damage caused by solder overflow during the existing high-frequency substrate welding process.

[0052] A high-frequency substrate soldering resist method, the method is applied to the production of products containing a high-frequency substrate and a cavity, the method comprising:

[0053] Apply solder to the preset welding area in the cavity, place the high-frequency substrate on the solder by using a tool, and apply a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, so that a closed space is formed between the high-frequency substrate and the cavity, and the solder is sealed in the closed space;

[0054] Placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber;

[0055] Placing the solidified silicone rubber product in a heating furnace so that the high-frequency substrate is fixed on the cavity through the solder;

[0056] Apply the corresponding solvent to the solidified silicone rubber and remove the silicone rubber.

[0057] Furthermore, before applying a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, and then placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber, the method further includes:

[0058] The product is subjected to a vacuum treatment so that the silicone rubber is in full contact with the surface of the cavity coating.

[0059] Furthermore, the vacuum degree in the vacuum treatment is: ≤0.1 bar, and the time is: 1 to 3 minutes.

[0060] Furthermore, the silicone rubber is GD414 silicone rubber.

[0061] Furthermore, the humidity in the constant temperature and humidity cabinet is set to be greater than 90%, and the temperature is set to be 80°C±5%.

[0062] Furthermore, the corresponding solvent applied on the silicone rubber is anhydrous ethanol.

[0063] Furthermore, the cavity is rectangular, a rectangular groove is provided in the middle, and a welding coating is provided at the bottom of the rectangular groove.

[0064] Furthermore, the high-frequency substrate is in the shape of a rectangular thin plate, and a welding plating layer is provided on the bottom.

[0065] Furthermore, the material of the welding plating layer is copper.

[0066] Furthermore, the inner diameter of the needle of the dispensing device is 0.51 mm and the outer diameter is 0.82 mm.

[0067] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0068] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A high-frequency substrate soldering resist method, characterized in that: The method is applied to the production of products containing high-frequency substrates and cavities, and the method comprises: Apply solder to the preset welding area in the cavity, place the high-frequency substrate on the solder by using a tool, and apply a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, so that a closed space is formed between the high-frequency substrate and the cavity, and the solder is sealed in the closed space; Placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber; Placing the solidified silicone rubber product in a heating furnace so that the high-frequency substrate is fixed on the cavity through the solder; Apply the corresponding solvent to the solidified silicone rubber and remove the silicone rubber.

2. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: Before applying a layer of silicone rubber close to the edge of the high-frequency substrate using a dispensing device, and then placing the product coated with the silicone rubber in a constant temperature and humidity cabinet to solidify the silicone rubber, the method further includes: The product is subjected to a vacuum treatment so that the silicone rubber is in full contact with the surface of the cavity coating.

3. A high-frequency substrate soldering resist method as claimed in claim 2, characterized in that: Vacuum degree during vacuum treatment: ≤0.1 bar, time: 1 to 3 minutes.

4. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The silicone rubber is GD414 silicone rubber.

5. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The humidity in the constant temperature and humidity cabinet is set to be greater than 90%, and the temperature is set to be 80°C±5%.

6. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The corresponding solvent applied on the silicone rubber is anhydrous ethanol.

7. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The cavity is rectangular, a rectangular groove is arranged in the middle, and a welding plating layer is arranged at the bottom of the rectangular groove.

8. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The high-frequency substrate is in the shape of a rectangular thin plate, and a welding plating layer is arranged on the bottom.

9. A high-frequency substrate soldering resist method as claimed in claim 7 or 8, characterized in that: The material of the welding plating layer is copper or nickel.

10. A high-frequency substrate soldering resist method as claimed in claim 1, characterized in that: The inner diameter of the needle of the dispensing device is 0.51 mm and the outer diameter is 0.82 mm.

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