Copper alloy chip heat dissipation shell and welding method thereof

Abstract

The invention discloses a copper alloy chip heat dissipation shell and a welding method thereof, and relates to the technical field of welding. Comprising the following steps that the surface of a copper alloy welding part is subjected to finish machining, and a pretreated welding part is obtained; after the pretreated welding part is tightly assembled, welding flux is clamped, technological parameters are set, resistance welding is conducted, and a welding joint is obtained; wherein the technological parameters comprise the welding power of 10 KVA to 20 KVA, the welding pressure of 0.5 T to 1.5 T and the welding time of 3 s to 8 s; and performing post-welding treatment on the welding joint to obtain a copper alloy chip heat dissipation shell product. Resistance welding is adopted, the welding quality is accurately controlled by adjusting current, pressure and welding flux, preparation of a high-quality welding connector is achieved, welding can be rapidly completed at a time, the welding efficiency is high, the yield of finished products is high, the welded finished products are free of defects such as air holes and hot cracks, and the hardness and the conductivity of the products both meet the use requirements.

Description

Technical Field

[0001] The present application relates to the field of welding technology, and in particular to a copper alloy chip heat dissipation housing and a welding method thereof. Background Art

[0002] With the continuous development of optical communication technology, the demand for high-speed optical modules is increasing. High-speed optical modules will generate a lot of heat when working, and a shell with good heat dissipation performance is required to ensure its normal operation. The existing zinc alloy shell can no longer meet the requirements, while copper alloy has high thermal conductivity, which can effectively conduct the heat inside the optical module, reduce the temperature of the chip, and improve the performance and reliability of the optical module. It is suitable for the preparation of chip heat dissipation shells. At present, for the connection of copper alloy chip heat dissipation shells, traditional processes generally use welding methods such as gas welding, inert gas shielded welding, and brazing. However, the following problems are usually encountered during the welding process: multiple welding is required to prevent the heat concentration of the welding workpiece and thus cause welding collapse, and the welding efficiency is low; the copper in the welding molten pool forms a low-melting point eutectic with the impurities therein, which makes copper and copper alloys have obvious hot brittleness, thereby generating thermal cracks; hydrogen pores are easily generated on the welding surface of the material; the performance of the welding joint does not meet the standard, the grains are coarsened, the plasticity decreases, and the corrosion resistance decreases. Based on this, the present application proposes a copper alloy chip heat dissipation shell and a welding method thereof. Summary of the invention

[0003] The main purpose of the present application is to provide a copper alloy chip heat dissipation housing and a welding method thereof, aiming to solve the technical problems that the existing welding process is prone to various defects and low yield.

[0004] To achieve the above purpose, the present application proposes a welding method for a copper alloy chip heat dissipation housing, comprising the following steps:

[0005] Finishing the surface of the copper alloy weldment to obtain a pre-treated weldment;

[0006] After the pre-treated welding parts are tightly assembled, the solder is clamped, the process parameters are set, and resistance welding is performed to obtain a welding joint; wherein the process parameters include: welding power of 10-20KVA, welding pressure of 0.5-1.5T, and welding time of 3-8s;

[0007] The welded joint is subjected to post-weld treatment to obtain a copper alloy chip heat dissipation housing product.

[0008] Optionally, the step of finishing the surface of the copper alloy weldment comprises:

[0009] Use a grinding wheel with a grit size of 40-80 to rough grind the surface of the copper alloy weldment, then use a grinding wheel with a grit size of 180-320 to fine grind it, and then use a cleaning fluid to clean it to remove impurities on the surface to be welded.

[0010] Optionally, the surface roughness of the pretreated weldment is Ra0.8-Ra3.2 μm.

[0011] Optionally, the step of clamping the solder after tightly assembling the pre-treated welded parts comprises:

[0012] The pre-treated welded parts are clamped on the welding fixture so that the pre-treated welded parts are tightly assembled, and the assembly accuracy is controlled to be 0.05-0.15mm. After the surface to be welded is kept horizontal, the solder is clamped so that the solder is pressed parallel to the welding mold.

[0013] Optionally, the solder is a silver solder, and the components of the silver solder include Ag, Cu, Zn and Sn;

[0014] The silver solder has a solidus temperature of 630°C and a liquidus temperature of 660°C.

[0015] Optionally, the silver solder comprises, by mass percentage, 54-56% Ag, 20-22% Cu, 20-24% Zn and 1.5-2.5% Sn.

[0016] Optionally, the solder is copper-tin solder, the solidus temperature of the copper-tin solder is 560°C, and the liquidus temperature of the copper-tin solder is 640°C.

[0017] Optionally, the copper-tin solder comprises 62-65% Cu and 10-15% Sn in percentage by mass.

[0018] Optionally, the step of performing post-weld treatment on the weld joint comprises:

[0019] The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol;

[0020] Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint;

[0021] The quality of the welded joints is then checked.

[0022] The present application also proposes a copper alloy chip heat dissipation housing, which is obtained by adopting the welding method of the copper alloy chip heat dissipation housing.

[0023] This application includes at least the following beneficial effects:

[0024] In view of the problems that the existing copper alloy chip heat dissipation shell welding process has low yield, material performance does not meet the standards, and multiple welding processes are required to prevent heat concentration and deformation, resulting in low welding efficiency, the present application adopts a resistance welding method, using electric current to pass through the copper alloy material to generate local heating, so that the low melting point solder melts quickly. Due to the high thermal conductivity of the copper alloy, the heat generated by welding is quickly conducted, and the welding can be completed in a short time, which not only improves production efficiency, but also avoids welding collapse caused by heat concentration of the welding workpiece, so that the welded joint has higher strength, which can meet its application as a chip heat dissipation shell with high load requirements; at the same time, the high thermal conductivity of the copper alloy makes the heat affected zone (HAZ) during resistance welding relatively small, avoiding excessive deformation of the substrate and degradation of metal properties, which is conducive to the preparation of precise copper alloy chip heat dissipation shells, and can effectively reduce the performance degradation problem caused by the excessive heat affected zone after welding. In addition, the present application accurately controls the quality of welding by adjusting the current, pressure and solder during the resistance welding process, and achieves the preparation of high-quality welded joints through appropriate parameter settings. Compared with other welding technologies, the welding process control of the present application is simpler and more reliable, and the welding can be completed quickly in one go, avoiding the concentration of welding defects such as electron beam welding and brazing. The welding efficiency is high, the finished product yield is high, and the cost advantage is obvious. The welded finished product has no defects such as pores and thermal cracks. The product hardness and electrical conductivity meet the use requirements and have high strength. It can ensure the reliability and stability of the chip heat dissipation housing in harsh environments, thereby protecting the internal components of the optical communication device from damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0026] Figure 1 This is a flow chart of a method for welding a copper alloy chip heat dissipation housing according to an embodiment of the present application.

[0027] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0029] In view of the technical problems existing in the prior art, the embodiments of the present application provide a method for welding a copper alloy chip heat dissipation housing, such as Figure 1 As shown, the following steps are included:

[0030] Step S10: finishing the surface of the copper alloy welded part to obtain a pre-treated welded part.

[0031] In the specific implementation process, since the surface is too rough, the contact quality of the welding joint will be reduced, which will further affect the wettability and bonding strength of the welding metal. When the surface of the copper alloy weldment is fine-machined, the present application uses a grinding wheel with a particle size of 40-80 to perform rough grinding on the surface of the copper alloy weldment, and then uses a grinding wheel with a particle size of 180-320 to perform fine grinding, and then uses a cleaning liquid to remove oil, oxides and other impurities on the surface to be welded. Through fine machining, the surface roughness of the pretreated weldment reaches Ra0.8-Ra3.2μm. Excessive surface roughness may cause welding defects such as pores, cracks, and slag inclusions. By controlling the surface roughness within the range of Ra0.8-Ra3.2μm, it can be ensured that the materials can be better integrated during the welding process, reducing the occurrence of welding defects such as pores, cracks, and slag inclusions.

[0032] Step S20: After the pre-treated welding parts are tightly assembled, the solder is clamped, the process parameters are set, and resistance welding is performed to obtain a welding joint.

[0033] In the specific implementation process, when the pre-treated welded parts are tightly assembled, the welding fixture is used to ensure the accuracy. The pre-treated welded parts are clamped on the welding fixture so that the pre-treated welded parts are tightly assembled, the gap is minimized as much as possible, and the assembly accuracy is controlled to be 0.05-0.15mm to ensure the smooth progress of the subsequent welding process. After the surface to be welded is kept horizontal, the solder is clamped so that the solder is pressed in parallel in the welding mold to ensure that the materials can be better fused during the welding process.

[0034] In the specific implementation process, the process parameters include: welding power of 10-20KVA, welding pressure of 0.5-1.5T, and welding time of 3-8s. The present application controls the welding power, pressure and time during the resistance welding process, so that the temperature change of the workpiece during the welding process is relatively controllable, thereby accurately controlling the quality of the welding. Preferably, the welding power is 10KVA, the welding pressure is 0.5T, and the welding time is 3s. The preparation of high-quality welded joints is achieved through appropriate parameter settings. Compared with other welding technologies, the welding process control of the present application is simpler and more reliable, and the welding can be completed quickly in one go.

[0035] Specifically, the solder is silver solder, and the components of the silver solder include Ag54-56%, Cu 20-22%, Zn 20-24% and Sn 1.5-2.5% by mass; the solidus temperature of the silver solder is 630°C, and the liquidus temperature is 660°C.

[0036] Specifically, the solder may also be copper-tin solder, and the components of the copper-tin solder include 62-65% Cu and 10-15% Sn by mass percentage; the solidus temperature of the copper-tin solder is 560° C., and the liquidus temperature is 640° C. Experimental verification shows that the hardness and conductivity of the product after welding with copper-tin solder meet the use requirements, and the cost is as low as 1 / 10 compared with silver solder, with obvious cost advantages.

[0037] Step S30: performing post-weld treatment on the welded joint to obtain a copper alloy chip heat dissipation housing product.

[0038] In a specific implementation process, when the weld joint is subjected to post-weld treatment, cooling water is used to directly cool the weld joint, wherein the cooling water contains 5% alcohol;

[0039] The welding area of ​​the welding joint is then pickled to remove the oxide layer and other impurities; the welding area is then mechanically polished using tools such as sandpaper and a polishing machine to remove surface oxides and improve the appearance of the welding joint; and fine sand particles are then sprayed to further remove surface oxides and impurities;

[0040] The weld points of the welded joints are then quality checked to improve the welding quality, ensure that the performance of the welded joints meets the requirements, and avoid defects that may occur during the welding process.

[0041] Specifically, the methods for quality inspection mainly include:

[0042] Visual inspection: Check the appearance of the welding area, including the shape, size and smoothness of the weld; Ultrasonic testing: Check whether there are defects such as pores and cracks inside the weld; X-ray inspection: Detect internal defects of the weld so that the weld meets higher precision requirements; Tensile test: Test the strength of the weld by tensile testing to evaluate its mechanical properties; Hardness test: Detect the hardness of the welding area to ensure that it meets the design requirements.

[0043] The embodiment of the present application further provides a copper alloy chip heat dissipation housing, which is obtained by the welding method of the copper alloy chip heat dissipation housing mentioned above.

[0044] The above technical solution of the present application is described in detail below in conjunction with specific embodiments.

[0045] Example 1

[0046] A method for welding a copper alloy chip heat dissipation housing comprises the following steps:

[0047] The surface of the copper alloy welded part was roughly ground using a 60-mesh grinding wheel, and then finely ground using a 260-mesh grinding wheel. The surface was then cleaned with a cleaning fluid to remove impurities on the surface to be welded, and a pre-treated welded part was obtained, the surface roughness of which was Ra1.6μm.

[0048] The pre-treated welding parts are clamped on the welding fixture so that the pre-treated welding parts are tightly assembled, and the assembly accuracy is controlled to be 0.10mm. After the surface to be welded is kept in a horizontal state, the solder is clamped so that the solder is pressed in parallel in the welding mold, and the process parameters are set to perform resistance welding to obtain a welding joint; wherein the process parameters include: welding power of 20KVA, welding pressure of 1.0T, and welding time of 8s; the solder is silver solder, and the components of the silver solder include Ag 55%, Cu 21%, Zn 22% and Sn 2.0%; the solidus temperature of the silver solder is 630°C, and the liquidus temperature is 660°C;

[0049] The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol;

[0050] Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint;

[0051] The quality of the solder joints is then inspected to obtain a copper alloy chip heat dissipation housing product.

[0052] Example 2

[0053] A method for welding a copper alloy chip heat dissipation housing comprises the following steps:

[0054] The surface of the copper alloy weldment was roughly ground using a 40-mesh grinding wheel, and then finely ground using a 180-mesh grinding wheel. The surface was then cleaned with a cleaning fluid to remove impurities on the surface to be welded, and a pre-treated weldment was obtained, the surface roughness of which was Ra3.2μm.

[0055] The pre-treated welding parts are clamped on the welding fixture so that the pre-treated welding parts are tightly assembled, and the assembly accuracy is controlled to be 0.05mm. After the surface to be welded is kept in a horizontal state, the solder is clamped so that the solder is pressed in parallel in the welding mold, and the process parameters are set to perform resistance welding to obtain a welding joint; wherein the process parameters include: welding power of 15KVA, welding pressure of 0.5T, and welding time of 5s; the solder is silver solder, and the components of the silver solder include Ag 54%, Cu 20%, Zn 24% and Sn 2.0%; the solidus temperature of the silver solder is 630°C, and the liquidus temperature is 660°C;

[0056] The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol;

[0057] Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint;

[0058] The quality of the solder joints is then inspected to obtain a copper alloy chip heat dissipation housing product.

[0059] Example 3

[0060] A method for welding a copper alloy chip heat dissipation housing comprises the following steps:

[0061] The surface of the copper alloy welded part was roughly ground using a grinding wheel with a grit of 80 mesh, and then finely ground using a grinding wheel with a grit of 320 mesh. The surface of the welded part was then cleaned with a cleaning fluid to remove impurities on the surface to be welded, and the pre-treated welded part had a surface roughness of Ra0.8μm.

[0062] The pre-treated welding parts are clamped on the welding fixture so that the pre-treated welding parts are tightly assembled, and the assembly accuracy is controlled to be 0.05mm. After the surface to be welded is kept in a horizontal state, the solder is clamped so that the solder is pressed in parallel in the welding mold, and the process parameters are set to perform resistance welding to obtain a welding joint; wherein the process parameters include: welding power of 10KVA, welding pressure of 0.5T, and welding time of 3s; the solder is silver solder, and the components of the silver solder include Ag 56%, Cu 22%, Zn 24% and Sn 1.0%; the solidus temperature of the silver solder is 630°C, and the liquidus temperature is 660°C;

[0063] The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol;

[0064] Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint;

[0065] The quality of the solder joints is then inspected to obtain a copper alloy chip heat dissipation housing product.

[0066] Example 4

[0067] A method for welding a copper alloy chip heat dissipation housing comprises the following steps:

[0068] The surface of the copper alloy weldment was roughly ground using a 70-mesh grinding wheel, and then finely ground using a 300-mesh grinding wheel. The surface was then cleaned with a cleaning fluid to remove impurities on the surface to be welded, and the pre-treated weldment was obtained, and its surface roughness was Ra1.2μm.

[0069] The pre-treated welded parts are clamped on the welding fixture so that the pre-treated welded parts are tightly assembled, and the assembly accuracy is controlled to be 0.05mm. After the surface to be welded is kept in a horizontal state, the solder is clamped so that the solder is pressed in parallel in the welding mold, and the process parameters are set to perform resistance welding to obtain a welded joint; wherein the process parameters include: welding power of 10KVA, welding pressure of 0.5T, and welding time of 3s; the solder is copper-tin solder, and the components of the copper-tin solder include Cu 63% and Sn 14% by mass percentage; the solidus temperature of the copper-tin solder is 560°C, and the liquidus temperature is 640°C;

[0070] The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol;

[0071] Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint;

[0072] The quality of the solder joints is then inspected to obtain a copper alloy chip heat dissipation housing product.

[0073] Comparative Example 1

[0074] The copper alloy welding parts are welded by adopting the existing vacuum brazing process to obtain the copper alloy chip heat dissipation shell product.

[0075] Comparative Example 2

[0076] The copper alloy welding parts are welded by using the existing electron beam welding process to obtain the copper alloy chip heat dissipation shell product.

[0077] Experimental example

[0078] The conductivity, hardness and contact strength of the copper alloy chip heat dissipation housing prepared in the examples and comparative examples of the present application were tested, and the test results are shown in Table 1. The conductivity test was carried out in accordance with the standard "GB / T 5321-2018 Determination of Metal Conductivity"; the hardness test was carried out in accordance with the standard "GB / T231.2-2002 Metal Brinell Hardness Test"; and the contact strength test was carried out in accordance with the standard "ISO 15614 Welding Procedure Specification - Welding Procedure Assessment".

[0079] Table 1

[0080] Group Conductivity(Ms / m) Hardness (HB) Contact strength (MPa) Example 1 40.6 69 115 Example 2 43.1 73 110 Example 3 47.8 89 93 Example 4 46.9 85 90 Comparative Example 1 34.7 60 89 Comparative Example 2 36.1 62 83

[0081] It can be seen from Table 1 that compared with the copper alloy chip heat dissipation shell obtained by the existing vacuum brazing process and electron beam welding process, the copper alloy chip heat dissipation shell obtained by the welding method of the present application has better performance in terms of electrical conductivity, hardness and contact strength, and the product performance meets the use requirements.

[0082] In summary, compared with the prior art, the present application has at least the following beneficial effects:

[0083] The present application adopts the method of resistance welding, and uses electric current to pass through the copper alloy material to generate local heating, so that the low-melting point solder melts quickly. Due to the high thermal conductivity of the copper alloy, the heat generated by welding is quickly conducted, and the welding can be completed in a short time, which not only improves the production efficiency, but also avoids the welding collapse caused by the heat concentration of the welding workpiece, so that the welded joint has a higher strength, which can meet its application as a chip heat dissipation shell with high load requirements; at the same time, the high thermal conductivity of the copper alloy makes the heat affected zone (HAZ) during resistance welding relatively small, avoiding excessive deformation of the substrate and degradation of the metal properties, which is conducive to the preparation of a precise copper alloy chip heat dissipation shell, and can effectively reduce the performance degradation problem caused by the excessive heat affected zone after welding. In addition, the present application accurately controls the quality of welding by adjusting the current, pressure and solder during the resistance welding process, and achieves the preparation of high-quality welded joints through appropriate parameter settings. Compared with other welding technologies, the welding process control of the present application is simpler and more reliable, and the welding can be completed quickly in one go, avoiding the concentration of welding defects such as electron beam welding and brazing. The welding efficiency is high, the finished product yield is high, and the cost advantage is obvious. The welded finished product has no defects such as pores and thermal cracks. The product hardness and electrical conductivity meet the use requirements and have high strength. It can ensure the reliability and stability of the chip heat dissipation housing in harsh environments, thereby protecting the internal components of the optical communication device from damage.

[0084] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for welding a copper alloy chip heat dissipation housing, characterized in that: The following steps are involved: Finishing the surface of the copper alloy weldment to obtain a pre-treated weldment; After the pre-treated welding parts are tightly assembled, the solder is clamped, the process parameters are set, and resistance welding is performed to obtain a welding joint; wherein the process parameters include: welding power of 10-20KVA, welding pressure of 0.5-1.5T, and welding time of 3-8s; The welded joint is subjected to post-weld treatment to obtain a copper alloy chip heat dissipation housing product.

2. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The step of finishing the surface of the copper alloy weldment comprises: Use a grinding wheel with a grit size of 40-80 to rough grind the surface of the copper alloy weldment, then use a grinding wheel with a grit size of 180-320 to fine grind it, and then use a cleaning fluid to clean it to remove impurities on the surface to be welded.

3. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The surface roughness of the pretreated welded part is Ra0.8-Ra3.2 μm.

4. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The step of clamping the solder after the pre-treated welded parts are tightly assembled comprises: The pre-treated welded parts are clamped on the welding fixture so that the pre-treated welded parts are tightly assembled, and the assembly accuracy is controlled to be 0.05-0.15mm. After the surface to be welded is kept horizontal, the solder is clamped so that the solder is pressed parallel to the welding mold.

5. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The solder is a silver solder, and the components of the silver solder include Ag, Cu, Zn and Sn; The silver solder has a solidus temperature of 630°C and a liquidus temperature of 660°C.

6. The welding method of the copper alloy chip heat dissipation housing according to claim 6, characterized in that: Calculated by mass percentage, the silver solder comprises 54-56% Ag, 20-22% Cu, 20-24% Zn and 1.5-2.5% Sn.

7. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The solder is copper-tin solder, the solidus temperature of the copper-tin solder is 560°C, and the liquidus temperature is 640°C.

8. The welding method of the copper alloy chip heat dissipation housing according to claim 7, characterized in that: Calculated by mass percentage, the copper-tin solder comprises 62-65% Cu and 10-15% Sn.

9. The welding method of the copper alloy chip heat dissipation housing according to claim 1, characterized in that: The step of performing post-weld treatment on the weld joint comprises: The welding joint is cooled by cooling water, wherein the cooling water contains 5% alcohol; Then, pickling, mechanical grinding and sand blasting are sequentially performed on the welding area of ​​the welding joint; The quality of the welded joints is then checked.

10. A copper alloy chip heat dissipation housing, characterized in that: The method is obtained by welding the copper alloy chip heat dissipation housing according to any one of claims 1 to 9.

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