Gate pole copper needle welding process of silicon controlled rectifier power module

Abstract

The invention discloses a gate pole copper needle welding process of a silicon controlled rectifier power module, which comprises the following steps: preparing the silicon controlled rectifier power module for welding processing, a carrier bottom plate of the silicon controlled rectifier power module, a gate pole copper needle, a vacuum furnace and soldering tin, and mounting the prepared silicon controlled rectifier power module on the carrier bottom plate, placing a gate pole copper needle at a welding pin of the silicon controlled rectifier, placing a prepared product into a vacuum furnace, locking a bin gate, welding and connecting the silicon controlled rectifier power module by adopting a welding material, completing the welding of the silicon controlled rectifier power module, cooling the vacuum furnace, and then discharging nitrogen in the vacuum furnace; a copper needle process is adopted in a gate pole copper needle welding process of the silicon controlled power module, a gate pole copper needle adopts an oxygen-free copper material salient point forming and gold plating welding mode in the welding process, and the copper needle adopts one-time high-temperature lead-free vacuum welding to ensure that the copper needle is firmer; in this way, better conductivity and weldability are achieved in the welding process.

Description

Technical Field

[0001] The invention relates to the technical field of gate copper pin welding, in particular to a gate copper pin welding process for a thyristor power module. Background Art

[0002] Silicon controlled rectifier (SCR) is a high-power electrical component, also known as thyristor. It has the advantages of small size, high efficiency and long life. In the automatic control system, it can be used as a high-power driver to control high-power equipment with low-power controls. It has been widely used in AC and DC motor speed control systems, power control systems and follow-up systems.

[0003] There are two types of thyristors: unidirectional thyristors and bidirectional thyristors. Bidirectional thyristors are also called three-terminal bidirectional thyristors, or TRIACs for short. Bidirectional thyristors are structurally equivalent to two unidirectional thyristors connected in reverse. This type of thyristor has a bidirectional conduction function. Its on-off state is determined by the control electrode G. Adding a positive pulse (or negative pulse) to the control electrode G can make it conduct in the forward (or reverse) direction. The advantage of this device is that the control circuit is simple and there is no reverse withstand voltage problem, so it is particularly suitable for use as an AC contactless switch.

[0004] The unidirectional thyristor we use is also called the ordinary thyristor. It is composed of four layers of semiconductor materials, with three PN junctions and three electrodes to the outside (the electrode leading out of the P-type semiconductor is called the anode A, the electrode leading out of the third layer of the P-type semiconductor is called the control electrode G, and the electrode leading out of the fourth layer of the N-type semiconductor is called the cathode K.

[0005] The P1N1P2N2 four-layer three-terminal device with silicon single crystal as the basic material is commonly known as silicon crystal thyristor, or thyristor T for short, internationally because its characteristics are similar to those of vacuum thyristor. Because thyristor was originally used in static rectification, it is also called silicon controlled rectifier element, or thyristor SCR for short.

[0006] In terms of performance, thyristor not only has unidirectional conductivity, but also has more valuable controllability than silicon rectifier components (commonly known as "dead silicon"). It has only two states: on and off.

[0007] Thyristors can control high-power electromechanical equipment with milliampere currents. If this power is exceeded, the switching losses of the components will increase significantly, and the average current allowed to pass will decrease. In this case, the nominal current should be reduced.

[0008] However, the current thyristor welding is all done by wire welding, so the thyristor module welded in this way is not stable enough after long-term use, and the conductivity is not good enough. Therefore, an improved technology is urgently needed to solve this problem in the prior art. Summary of the invention

[0009] The object of the present invention is to provide a gate copper needle welding process for a thyristor power module, which adopts a copper needle process. During the welding process, the gate copper needle is made of oxygen-free copper and is gold-plated with a bump. The copper needle is welded in a one-time high-temperature lead-free vacuum welding to ensure that the copper needle is more firm. In this way, the welded thyristor module has better conductivity and weldability, so as to solve the problems raised in the above background technology.

[0010] To achieve the above object, the present invention provides the following technical solution: a gate copper pin welding process of a thyristor power module, the thyristor power module welding process includes the following process:

[0011] S1, preparing a thyristor power module for welding, a carrier base plate of the thyristor power module, a gate copper pin, a vacuum furnace and solder;

[0012] S2, install the prepared thyristor power module on the carrier base plate, and place the gate copper pin at the welding foot of the thyristor;

[0013] S3. Put the prepared products into the vacuum furnace, lock the door, evacuate the vacuum furnace to -95KP at room temperature for the first time, fill the vacuum furnace with nitrogen for 40 seconds, and wait for the vacuum furnace to heat up to 180 degrees;

[0014] The vacuum furnace was evacuated to -95KP for the second time, nitrogen was filled into the vacuum furnace for 40 seconds, and the temperature was raised to 250 degrees;

[0015] The third time, the vacuum furnace was evacuated to -95KP, and nitrogen was filled to -95KP for 40 seconds, so that the temperature in the vacuum furnace was raised to 250 degrees, and the thyristor power module was welded and connected using welding materials;

[0016] S4. After the welding of the thyristor power module is completed, the vacuum furnace is cooled to 100 degrees, and then the nitrogen inside the vacuum furnace is exhausted, and the door is opened to take out the thyristor power module that has been welded.

[0017] Preferably, the thyristor power module welding process in S1 prepares conductive metal parts for welding connection between modules.

[0018] Preferably, the carrier base plate of the thyristor power module in S1 is an integrated base plate, and a thyristor power module mounting groove is provided inside the carrier base plate of the thyristor power module.

[0019] Preferably, the gate copper pin welding process in S1 adopts a copper pin welding process which is an oxygen-free copper material bumping and gold-plating welding method.

[0020] Preferably, the thyristor power module and the gate copper pin are welded by one-time high-temperature lead-free vacuum welding.

[0021] Preferably, in S3, nitrogen is filled for 40 seconds for the first time, the vacuum furnace is heated to 180 degrees and maintained for 5 minutes, nitrogen is filled for 40 seconds for the second time, the vacuum furnace is heated to 250 degrees and maintained for 5 minutes, and nitrogen is filled for 40 seconds for the third time, the vacuum furnace is heated to 250 degrees and maintained for 5 minutes.

[0022] Preferably, in S4, the vacuum furnace is cooled to 100 degrees by water circulation cooling, and the circulating cooling water is low-temperature water cooling water rapidly cooled by liquid nitrogen, and the temperature of the low-temperature water cooling water is between 1-3 degrees.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The carrier base plate of the thyristor power module is an integrated base plate, and a thyristor power module mounting groove is provided inside the carrier base plate of the thyristor power module, which is used to position each thyristor power module, thereby effectively improving the overall stability of the device;

[0025] (2) The gold-plated welding of oxygen-free copper material makes the gate copper pin and the welding foot of the thyristor more firmly fixed, and the gold-plated welding of the bump has better anti-oxidation effect;

[0026] (3) The copper pin welding process used in the gate copper pin welding process uses oxygen-free copper material to make gold-plated bumps for welding. The thyristor power module and the gate copper pin are welded in a one-time high-temperature lead-free vacuum welding to ensure that the copper pin is more solid;

[0027] (4) The vacuum furnace is cooled to 100 degrees by water circulation cooling. The circulating cooling water is low-temperature water cooling water that is rapidly cooled by liquid nitrogen. The temperature of the low-temperature water cooling water is between 1-3 degrees. The low-temperature circulating cooling water has a better cooling effect and greatly improves the cooling efficiency.

[0028] (5) The copper needle process is used in the gate copper needle welding process of the thyristor power module. During the welding process, the gate copper needle is made of oxygen-free copper and gold-plated. The copper needle is welded by one-time high-temperature lead-free vacuum welding to ensure that the copper needle is more firm, so that the welded thyristor module has better conductivity and weldability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of the gate copper pin welding process of the thyristor power module. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0034] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that can be implemented in this application, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this application without affecting the effects that can be produced by this application and the purposes that can be achieved. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the implementation of this application. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of this application without substantial change in the technical content.

[0035] See also Figure 1 The present invention provides a technical solution: a gate copper pin welding process of a thyristor power module, the thyristor power module welding process includes the following processes:

[0036] Prepare the thyristor power module, the carrier base plate of the thyristor power module, the gate copper pin, the vacuum furnace and the solder for welding. Before welding the thyristor power module, it is necessary to prepare the conductive metal parts for welding connection between the modules.

[0037] The carrier base plate of the thyristor power module is an integrated base plate, and a thyristor power module mounting groove is provided inside the carrier base plate of the thyristor power module for positioning each thyristor power module, thereby effectively improving the overall stability of the device.

[0038] Install the prepared thyristor power module on the carrier base plate, and place the gate copper needle at the welding foot of the thyristor. First, use oxygen-free copper material to make gold-plated bumps on the gate copper needle and the welding foot of the thyristor. The gold-plated bumps on the oxygen-free copper material can make the gate copper needle and the welding foot of the thyristor more firmly fixed. In addition, the gold-plated bump welding has better anti-oxidation effect.

[0039] The prepared products are placed in the vacuum furnace, the door is locked, and the vacuum furnace is evacuated to -95KP for the first time at room temperature. Nitrogen is filled into the vacuum furnace for 40 seconds, and then the vacuum furnace is heated to 180 degrees and maintained for 5 minutes. The thyristor power module and the conductive material are welded with oxygen-free copper bumps.

[0040] The vacuum furnace was evacuated to -95KP for the second time, and nitrogen was filled into the vacuum furnace for 40 seconds. The temperature was raised to 250 degrees and maintained for 5 minutes. The vacuum furnace was evacuated to -95KP for the third time, and nitrogen was filled into the vacuum furnace for 40 seconds. The temperature in the vacuum furnace was raised to 250 degrees and maintained for 5 minutes. The thyristor power module and the conductive material were welded with oxygen-free copper bumps.

[0041] The first time nitrogen is filled for 40 seconds, the vacuum furnace is heated to 180 degrees and kept for 5 minutes. The second time nitrogen is filled for 40 seconds, the vacuum furnace is heated to 250 degrees and kept for 5 minutes. The third time nitrogen is filled for 40 seconds, the vacuum furnace is heated to 250 degrees and kept for 5 minutes. In this way, the materials used for welding can be well melted and bonded together during the welding process.

[0042] After each nitrogen filling, welding materials are used to weld the gate copper pins on adjacent thyristor power modules to the conductive connectors under different temperature environments. The gate copper pin welding process adopts the copper pin welding process. This process uses oxygen-free copper material to make bumps and gold-plated welding. The thyristor power module and the gate copper pin are welded by one-time high-temperature lead-free vacuum welding to ensure that the copper pin is more firm.

[0043] After the welding of the thyristor power module is completed, the vacuum furnace is cooled to 100 degrees. The water circulation cooling method is used to cool the vacuum furnace to 100 degrees. The circulating cooling water is low-temperature water cooling water that is rapidly cooled by liquid nitrogen. The temperature of the low-temperature water cooling water is between 1-3 degrees. The low-temperature circulating cooling water has a better cooling effect and greatly improves the cooling efficiency. Then the nitrogen inside the vacuum furnace is discharged, and the door is opened to take out the thyristor power module that has been welded.

[0044] Embodiment 1,

[0045] Put the prepared thyristor power module into the vacuum furnace, lock the door, and evacuate the vacuum furnace to -95KP for the first time at room temperature. Fill the vacuum furnace with nitrogen for 45 seconds, wait for the vacuum furnace to heat up to 180 degrees and keep it for 5 minutes. Use oxygen-free copper material to make bumps between the thyristor power module and the conductive material for welding.

[0046] The vacuum furnace was evacuated to -95KP for the second time, nitrogen was filled into the vacuum furnace for 45 seconds, the temperature was raised to 250 degrees and maintained for 5 minutes.

[0047] The vacuum furnace was evacuated to -95KP for the third time, and nitrogen was filled to -95KP for 45 seconds. The temperature in the vacuum furnace was raised to 250 degrees and maintained for 5 minutes. The thyristor power module and the conductive material were welded by bumping with oxygen-free copper.

[0048] Each time nitrogen is filled for 45 seconds, the vacuum furnace is heated to 180 degrees and kept for 5 minutes. The second time nitrogen is filled for 40 seconds, the vacuum furnace is heated to 250 degrees and kept for 5 minutes. The third time nitrogen is filled for 40 seconds, the vacuum furnace is heated to 250 degrees and kept for 5 minutes. In this way, the materials used for welding can be well melted and bonded together during the welding process.

[0049] Embodiment 2,

[0050] Put the prepared thyristor power module into the vacuum furnace, lock the door, and evacuate the vacuum furnace to -95KP for the first time at room temperature. Fill the vacuum furnace with nitrogen for 60 seconds, wait for the vacuum furnace to heat up to 180 degrees and keep it for 5 minutes. Use oxygen-free copper material to make bumps between the thyristor power module and the conductive material for welding.

[0051] The vacuum furnace was evacuated to -95KP for the second time, nitrogen was filled into the vacuum furnace for 60 seconds, and the temperature was raised to 250 degrees and maintained for 5 minutes.

[0052] The vacuum furnace was evacuated to -95KP for the third time, and nitrogen was filled to -95KP for 45 seconds. The temperature in the vacuum furnace was raised to 340 degrees and maintained for 5 minutes. The thyristor power module and the conductive material were welded by bumping with oxygen-free copper.

[0053] Each time nitrogen is filled for 60 seconds, the vacuum furnace is heated to 180 degrees and kept for 5 minutes. The second time nitrogen is filled for 60 seconds, the vacuum furnace is heated to 250 degrees and kept for 5 minutes. The third time nitrogen is filled for 60 seconds, the vacuum furnace is heated to 340 degrees and kept for 5 minutes. In this way, the materials used for welding can be well melted and bonded together during the welding process.

[0054] Embodiment 3,

[0055] Put the prepared thyristor power module into the vacuum furnace, lock the door, and evacuate the vacuum furnace to -95KP for the first time at room temperature. Fill the vacuum furnace with nitrogen for 45 seconds, wait for the vacuum furnace to heat up to 180 degrees and keep it for 5 minutes. Use oxygen-free copper material to make bumps between the thyristor power module and the conductive material for welding.

[0056] The vacuum furnace was evacuated to -95KP for the second time, nitrogen was filled into the vacuum furnace for 55 seconds, the temperature was raised to 250 degrees and maintained for 5 minutes.

[0057] The vacuum furnace was evacuated to -95KP for the third time, and nitrogen was filled to -95KP for 65 seconds. The temperature in the vacuum furnace was raised to 340 degrees and maintained for 5 minutes. The thyristor power module and the conductive material were welded by bumping with oxygen-free copper.

[0058] The first time nitrogen is filled, it takes 45 seconds, the vacuum furnace is heated to 180 degrees and then maintained for 5 minutes. The second time nitrogen is filled, it takes 55 seconds, the vacuum furnace is heated to 250 degrees and then maintained for 5 minutes. The third time nitrogen is filled, it takes 65 seconds, the vacuum furnace is heated to 340 degrees and then maintained for 5 minutes. The time of nitrogen injection is progressive to complete the welding process of the thyristor power module.

[0059] The strength, welding integrity and post-welding process of the thyristor power modules welded under three different nitrogen introduction times in Example 1, Example 2 and Example 3 were tested. When the nitrogen introduction time was 40 seconds, the thyristor power modules completed had better performance parameters.

[0060] The copper needle process is used in the gate copper needle welding process of the thyristor power module. During the welding process, the gate copper needle is made of oxygen-free copper and gold-plated. The copper needle is welded by one-time high-temperature lead-free vacuum welding to ensure that the copper needle is more firm, so that the welded thyristor module has better conductivity and weldability.

[0061] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gate copper pin welding process for a thyristor power module, characterized in that: The thyristor power module welding process includes the following processes: S1, preparing a thyristor power module for welding, a carrier base plate of the thyristor power module, a gate copper pin, a vacuum furnace and solder; S2, install the prepared thyristor power module on the carrier base plate, and place the gate copper pin at the welding foot of the thyristor; S3. Put the prepared products into the vacuum furnace, lock the door, evacuate the vacuum furnace to -95KP for the first time at room temperature, fill the vacuum furnace with nitrogen for 40 seconds, and wait for the vacuum furnace to heat up to 180 degrees; The vacuum furnace was evacuated to -95KP for the second time, nitrogen was filled into the vacuum furnace for 40 seconds, and the temperature was raised to 250 degrees; The third time, the vacuum furnace was evacuated to -95KP, and nitrogen was filled to -95KP for 40 seconds, so that the temperature in the vacuum furnace was raised to 250 degrees, and the thyristor power module was welded and connected using welding materials; S4. After the welding of the thyristor power module is completed, the vacuum furnace is cooled to 100 degrees, and then the nitrogen inside the vacuum furnace is exhausted, and the door is opened to take out the thyristor power module that has been welded.

2. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: The thyristor power module welding process in S1 prepares conductive metal parts for welding connection between modules.

3. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: The carrier base plate of the thyristor power module in S1 is an integrated base plate, and a thyristor power module mounting groove is arranged inside the carrier base plate of the thyristor power module.

4. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: The gate copper pin welding process in S1 adopts the copper pin welding process which is an oxygen-free copper material bumping and gold-plating welding method.

5. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: The thyristor power module and the gate copper pin are welded by one-time high-temperature lead-free vacuum welding.

6. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: The S3 is filled with nitrogen for the first time for 40 seconds, and the vacuum furnace is heated to 180 degrees and maintained for 5 minutes. The nitrogen is filled with nitrogen for the second time for 40 seconds, and the vacuum furnace is heated to 250 degrees and maintained for 5 minutes. The nitrogen is filled with nitrogen for the third time for 40 seconds, and the vacuum furnace is heated to 250 degrees and maintained for 5 minutes.

7. The gate copper pin welding process of a thyristor power module according to claim 1, characterized in that: In S4, the vacuum furnace is cooled to 100 degrees by water circulation cooling. The circulating cooling water is low-temperature water cooled rapidly by liquid nitrogen. The temperature of the low-temperature water cooling water is between 1 and 3 degrees.

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