Heat-resistant oxygen-free copper for IGBT (Insulated Gate Bipolar Translator) module and preparation method thereof

Abstract

The invention relates to the field of copper material processing, and discloses heat-resistant oxygen-free copper for an IGBT (Insulated Gate Bipolar Translator) module, the heat-resistant oxygen-free copper comprises the following preparation raw materials: 98 parts of copper, 0.17 part of phosphorus, 0.02 part of nickel and 0.01 part of silver, and the heat-resistant oxygen-free copper is prepared by the following steps: S1, pouring 98 parts of copper into a smelting furnace to melt the raw materials; s2, the smelting temperature in the smelting furnace is kept at 1500 DEG C or above; and S3, in the melting process of the copper raw materials, argon is continuously injected into the smelting furnace. According to the heat-resistant oxygen-free copper for the IGBT module and the preparation method of the heat-resistant oxygen-free copper, an oxygen-free melting process and electrolysis are carried out at the same time, impurities and oxygen in copper can be effectively removed, firstly, an oxygen-free environment is guaranteed in the machining process of a copper raw material, and then the heat-resistant oxygen-free copper for the IGBT module is obtained through subsequent copper sulfate and sulfuric acid electrolysis. According to the copper material, impurities in the preliminarily formed oxygen-free copper cannot be reduced, so that pure copper is decomposed, meanwhile, the oxidation resistance of the copper material can be enhanced through the added phosphorus nickel silver, and the high temperature resistance can be improved while the heat conductivity is increased.

Description

Technical Field

[0001] The present invention relates to the field of copper processing, and specifically to a heat-resistant oxygen-free copper for IGBT modules and a preparation method thereof. Background Art

[0002] An IGBT module is an electronic component that combines an insulated gate bipolar transistor and a diode, and is usually used in an efficient power electronic control system. IGBT modules are widely used in power conversion, industrial motor drive, rail transit, energy management, renewable energy, and other high-power electronic devices. It is an electronic switching device that can effectively control high voltage and high current.

[0003] In the environment where IGBT modules are applied, they need to withstand high voltage and high current loads. Therefore, the oxygen-free copper required for the IGBT transistors in the IGBT module needs to ensure current stability and overall heat resistance while withstanding high voltage and high current to ensure a high switching frequency. However, in some existing high-conductivity copper materials applied to IGBT transistors, the high temperature generated after frequent switching of high voltage and current will cause overload of the IGBT transistors, resulting in the failure of the IGBT module.

[0004] Therefore, there is an urgent need for a heat-resistant oxygen-free copper for IGBT modules to solve the above problems. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a heat-resistant oxygen-free copper for IGBT modules and a preparation method thereof, which have the advantages of good heat-resistant and conductive stability, and solve the problems in the above background art.

[0007] (II) Technical Solutions

[0008] To achieve the above object of heat-resistant and conductive stability, the present invention provides the following technical solution: A heat-resistant oxygen-free copper for IGBT modules, comprising the following preparation raw materials: 98 parts of copper, 0.17 parts of phosphorus, 0.02 parts of nickel, and 0.01 parts of silver.

[0009] Preferably, it includes the following steps:

[0010] S1: Pour 98 parts of copper into a melting furnace for melting of raw materials;

[0011] S2: Keep the melting temperature in the melting furnace above 1500 °C;

[0012] S3: Continuously inject argon gas into the melting furnace during the melting process of copper raw materials;

[0013] S4: Pour the molten copper alloy liquid into a horizontal continuous casting machine for horizontal continuous casting;

[0014] S5: Carry out pickling on the oxygen-free copper liquid obtained after smelting to further remove impurities in the copper liquid;

[0015] S6: Repeat the processing steps of S1 - S3 for the pickled oxygen-free copper and continue to add 0.17 parts of phosphorus, 0.02 parts of nickel, and 0.01 part of silver, and continue to melt the alloy metal;

[0016] S7: The molten copper alloy liquid obtained after melting is cooled again by horizontal continuous casting annealing to obtain alloy copper bars.

[0017] Preferably, the melting time in step S1 is not less than 2h.

[0018] Preferably, the purity of the argon gas injected in step S3 is not less than 90%.

[0019] Preferably, the pickling temperature in step S5 does not exceed 60°C.

[0020] Preferably, the pickling concentration in step S5 does not exceed 12%, and the pickling time does not exceed 15min.

[0021] Preferably, during the process of introducing argon gas into the furnace, it is necessary to ensure that the furnace lid of the furnace is in a closed state.

[0022] Preferably, the pickling solution in step S5 is composed of nitric acid and sulfuric acid, and the concentrations of nitric acid and sulfuric acid are 50 - 70g / L and 150 - 200g / L respectively.

[0023] Preferably, the horizontal continuous casting in step S4 includes the following specific steps:

[0024] S4a: Pour the copper alloy liquid into a horizontal continuous casting machine for continuous drawing and continuous casting work;

[0025] S4b: The drawing speed is calculated by the following formula:

[0026]

[0027] Where T p is the drawing stop interval time, V is the drawing speed, R is the cooling rate, L is the length of the mold, and k is the adjustment coefficient.

[0028] (III) Beneficial effects

[0029] Compared with the prior art, the present invention provides a heat-resistant oxygen-free copper for IGBT modules and its preparation method, which has the following beneficial effects:

[0030] The heat-resistant oxygen-free copper for IGBT modules and its preparation method can effectively remove impurities and oxygen in copper through the simultaneous process of oxygen-free melting and electrolysis. Firstly, an oxygen-free environment is ensured during the processing of copper raw materials, and then through subsequent electrolysis of copper sulfate and sulfuric acid, the impurities in the initially formed oxygen-free copper will not be reduced, thus decomposing pure copper. It can effectively remove impurities in copper raw materials without the presence of copper oxide. At the same time, the addition of phosphorus, nickel, and silver can ensure enhanced oxidation resistance of the copper material, increase the thermal conductivity, and also improve the high-temperature resistance. Detailed implementation mode

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Embodiment 1

[0033] The preferred embodiment of a heat-resistant oxygen-free copper for IGBT modules and its preparation method provided by the present invention is as follows: A heat-resistant oxygen-free copper for IGBT modules includes the following preparation raw materials: 98 parts of copper, 0.17 parts of phosphorus, 0.02 parts of nickel, and 0.01 parts of silver.

[0034] Among them, phosphorus can form copper phosphide with copper, and this compound can further enhance the oxidation resistance of copper at high temperatures. Nickel can improve the heat resistance and corrosion resistance of copper, especially significantly in high-temperature environments, greatly improving the stability under the continuous flow of high-voltage current in the IGBT module.

[0035] In this embodiment, the following steps are included:

[0036] S1: Pour 98 parts of copper into a furnace for melting of raw materials;

[0037] S2: Keep the melting temperature in the furnace above 1500 °C;

[0038] S3: Continuously inject argon into the furnace during the melting process of copper raw materials;

[0039] S4: Pour the molten copper alloy liquid into a horizontal continuous casting machine for horizontal continuous casting;

[0040] S5: Perform pickling on the oxygen-free copper liquid obtained after melting to further remove impurities in the copper liquid;

[0041] S6: Repeat the processing steps of S1 - S3 for the pickled oxygen - free copper, and simultaneously continue to add 0.17 parts of phosphorus, 0.02 parts of nickel, and 0.01 parts of silver, then continue with the melting of the alloy metal.

[0042] S7: The copper alloy liquid obtained after melting is cooled again by horizontal continuous casting annealing to obtain alloy copper rods.

[0043] Example 2

[0044] Based on Example 1, a preferred embodiment of the heat - resistant oxygen - free copper for IGBT modules and its preparation method provided by the present invention is as follows: The melting time in step S1 is not less than 2 h.

[0045] In this embodiment, the purity of the argon gas injected in step S3 is not less than 90%.

[0046] Furthermore, the pickling temperature in step S5 does not exceed 60°C.

[0047] Even further, the pickling concentration in step S5 does not exceed 12%, and the pickling time does not exceed 15 min.

[0048] In addition, during the process of introducing argon gas into the furnace, it is necessary to ensure that the furnace lid is in a closed state.

[0049] By closing the furnace lid and continuously introducing high - purity argon gas, it can be ensured that the copper raw material in the furnace will not form copper oxide on the surface during the melting process, making the formation of the overall oxygen - free copper smoother.

[0050] And, the pickling solution in step S5 is composed of nitric acid and sulfuric acid, and the concentrations of nitric acid and sulfuric acid are 50 - 70 g / L and 150 - 200 g / L respectively.

[0051] The horizontal continuous casting in step S4 includes the following specific steps:

[0052] S4a: Pour the copper alloy liquid into a horizontal continuous casting machine for continuous drawing and casting work.

[0053] S4b: The drawing speed is calculated by the following formula:

[0054]

[0055] Where T p is the drawing - stop interval time, V is the drawing speed, R is the cooling rate, L is the length of the mold, and k is the adjustment coefficient.

[0056] According to the variable factors of the substitution processing technology, the pulling stop interval adopted by this technology is calculated, which can effectively ensure that during the crystallization process of the overall copper material, surface defects are avoided at the junction of the primary crystallization zone and the secondary crystallization zone and at the solidified shell, ensuring the relative quality of the raw material, making the crystallization process more stable, ensuring the quality of crystal formation, and having no impact on the subsequent overall use of the module.

[0057] In summary, for the heat-resistant oxygen-free copper used in IGBT modules and its preparation method, through the simultaneous implementation of the oxygen-free melting process and electrolysis, impurities and oxygen in the copper can be effectively removed. First, an oxygen-free environment is ensured during the processing of the copper raw material, and then through the subsequent electrolysis of copper sulfate and sulfuric acid, the impurities in the initially formed oxygen-free copper will not be reduced, thus decomposing pure copper. At the same time, the addition of phosphorus, nickel, and silver can ensure enhanced oxidation resistance of the copper material, increase the thermal conductivity, and improve the high-temperature resistance.

[0058] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such process, method, article or device.

[0059] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat-resistant oxygen-free copper for an IGBT module, characterized in that: The preparation method comprises the following raw materials: 98 parts of copper, 0.17 parts of phosphorus, 0.02 parts of nickel and 0.01 parts of silver.

2. The method for preparing heat-resistant oxygen-free copper for IGBT modules according to claim 1, characterized in that: The following steps are involved: S1: Pour 98 parts of copper into a furnace to melt the raw materials; S2: Maintain the melting temperature in the furnace above 1500°C; S3: During the melting process of the copper raw material, argon gas is continuously injected into the furnace; S4: the molten copper alloy liquid is poured into a horizontal continuous casting machine for horizontal continuous casting; S5: pickling the oxygen-free copper liquid obtained after smelting to further remove impurities in the copper liquid; S6: Repeat the processing of steps S1-S3 on the oxygen-free copper after pickling, and continue to add 0.17 parts of phosphorus, 0.02 parts of nickel and 0.01 parts of silver, and continue to melt the alloy metal; S7: The copper alloy liquid obtained after melting is cooled again and horizontal continuous casting annealing is performed to obtain alloy copper columns.

3. The method for preparing heat-resistant oxygen-free copper for IGBT module according to claim 2, characterized in that: The melting time in step S1 is not less than 2 hours.

4. The method for preparing heat-resistant oxygen-free copper for IGBT module according to claim 2, characterized in that: The purity of the argon gas injected in step S3 is not less than 90%.

5. The method for preparing heat-resistant oxygen-free copper for IGBT module according to claim 2, characterized in that: The pickling temperature in step S5 does not exceed 60°C.

6. The method for preparing heat-resistant oxygen-free copper for IGBT modules according to claim 2, characterized in that: In step S5, the pickling concentration does not exceed 12%, and the pickling time does not exceed 15 minutes.

7. The method for preparing heat-resistant oxygen-free copper for IGBT modules according to claim 2, characterized in that: During the process of introducing argon into the furnace, it is necessary to ensure that the furnace cover is in a closed state.

8. The method for preparing heat-resistant oxygen-free copper for IGBT modules according to claim 2, characterized in that: The pickling solution in step S5 is composed of nitric acid and sulfuric acid, and the concentrations of nitric acid and sulfuric acid are 50-70 g / L and 150-200 g / L respectively.

9. The method for preparing heat-resistant oxygen-free copper for IGBT module according to claim 2, characterized in that: The horizontal continuous casting in step S4 includes the following specific steps: S4a: pouring the copper alloy liquid into the horizontal continuous casting machine for continuous drawing and continuous casting; S4b: The casting speed is calculated by the following formula: Where T p is the pulling interval, V is the pulling speed, R is the cooling rate, L is the length of the crystallizer, and k is the adjustment coefficient.

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