Positioning fixtures and welding equipment for welding insulated gate bipolar transistors

Abstract

This utility model relates to the field of welding assembly technology, and provides a positioning fixture and welding equipment for welding insulated-gate bipolar transistors (IGBTs). The positioning fixture has a support base plate with multiple first supports and multiple second supports spaced apart. The first supports support the circuit board, and the second supports support the pads. A support tray is mounted on the first supports and has a receiving cavity for embedding the circuit board. A pressure plate assembly is located above the support tray and applies pressure to the circuit board and positions the IGBT. A clearance window is provided on the pressure plate assembly at a position corresponding to the pins of the IGBT, and the size of the clearance window matches the movement trajectory of the soldering iron tip. This utility model can stably support the circuit board and accurately position the IGBT, adapting to the operational requirements of spot welding machines and solving the welding efficiency and quality problems of double-sided through-hole IGBTs.

Description

Technical Field

[0001] This utility model relates to the field of welding assembly technology, and in particular to a positioning fixture and welding equipment for welding insulated gate bipolar transistors. Background Technology

[0002] With the technological advancements in new energy power generation and energy storage systems, energy storage inverters, as the core devices for power conversion and storage, are facing increasingly stringent requirements for power density and reliability. Currently, mainstream energy storage inverters generally employ IGBTs (Insulated Gate Bipolar Transistors) as their core components, which are used in large quantities and have high integration, placing stringent demands on assembly processes.

[0003] In the circuit board design of energy storage inverters, due to functional zoning and electrical connection requirements, IGBTs are often distributed on both sides of the circuit board along with plug-in connectors, plug-in aluminum electrolytic capacitors, and other non-uniformly arranged plug-in components. This non-uniform layout necessitates double-sided mounting of plug-in components. Traditional manual soldering processes require frequent switching of the operating side, resulting in low soldering efficiency. The soldering time per board increases exponentially with the number of IGBTs. Furthermore, the soldering quality is unstable, and manual operation is susceptible to fatigue and experience differences, leading to a high rate of defects such as cold solder joints and misaligned solder joints, making production line operations difficult.

[0004] To address the aforementioned issues, spot welding machines have been introduced to replace manual welding. Spot welding machines control the movement trajectory and temperature parameters of the soldering iron tip through programming, theoretically enabling standardized and highly repeatable welding operations, thus improving welding efficiency and quality. However, the stable operation of spot welding machines depends on precise positioning of the welding position.

[0005] In actual assembly, although IGBTs are inserted into the circuit board via plug-in connectors, gaps exist between their pins and the sockets, causing the IGBTs to float before soldering. While spacers are placed between the circuit board and the IGBTs, these spacers only support the IGBTs' weight and cannot effectively constrain their position. This makes it difficult to match the program coordinates of the spot welding machine with the actual position of the IGBTs, and the soldering iron tip is prone to poor contact or misalignment, leading to soldering failure and preventing the spot welding machine from achieving its efficiency advantages. Utility Model Content

[0006] This invention provides a positioning fixture and welding equipment for welding insulated gate bipolar transistors (IGBTs), which solves the above-mentioned technical defects in the prior art. It can stably support the circuit board and accurately position the IGBTs to meet the operational requirements of spot welding machines and solve the welding efficiency and quality problems of double-sided plug-in IGBTs.

[0007] The first aspect of this utility model provides a positioning fixture for welding insulated-gate bipolar transistors (IGBTs), wherein the IGBT is welded to a circuit board, and a spacer is provided between the circuit board and the IGBT, comprising:

[0008] A supporting base plate is provided with a plurality of first supporting members and a plurality of second supporting members, which are spaced apart; the plurality of first supporting members are used to support the circuit board, and the plurality of second supporting members are used to support the pad block;

[0009] A support tray is mounted on the first support member, and the support tray is provided with a receiving cavity for embedding the circuit board;

[0010] A pressure plate assembly, located above the support tray, is used to apply pressure to the circuit board and to position the insulated gate bipolar transistor. The pressure plate assembly has a clearance window at a position corresponding to the pin of the insulated gate bipolar transistor, and the size of the clearance window matches the movement trajectory of the soldering iron tip.

[0011] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, the second support member includes:

[0012] A support sleeve is provided on the support base plate;

[0013] An elastic element is embedded inside the support sleeve;

[0014] A support sleeve rod is fitted inside the support sleeve, with one end of the support sleeve rod abutting against the elastic element and the other end of the support sleeve rod abutting against the pad block.

[0015] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, one of the support sleeve and the support rod is provided with a guide member along the axial direction, and the other of the support sleeve and the support rod is provided with a mating member, which slides with the guide member for guiding.

[0016] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, the guide includes a guide groove that extends axially along the support sleeve rod;

[0017] The mating component includes at least one guide post, which is spaced apart on the support sleeve and extends into the interior of the guide groove.

[0018] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, the pressure plate assembly includes:

[0019] A positioning plate is provided with a first positioning post and a second positioning post. The first positioning post is used to be inserted into the threaded hole of the pad, and the second positioning post is used to be inserted into the process hole of the insulated gate bipolar transistor itself.

[0020] The pressure plate body is pressed onto the positioning plate;

[0021] The clearance window is located on the pressure plate body and at a position corresponding to the pin of the insulated gate bipolar transistor.

[0022] The positioning fixture for welding insulated gate bipolar transistors provided by this utility model further includes a third support member, which is located between the plane of the pressure plate body and the support tray.

[0023] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, the third support member is detachably connected to the pressure plate body, and the side of the third support member away from the pressure plate body abuts against the support tray and the circuit board.

[0024] The positioning fixture for welding insulated gate bipolar transistors provided by this utility model further includes:

[0025] A locking assembly is connected to the support tray and the pressure plate assembly respectively, and is used to fix the support tray and the pressure plate assembly so as to keep the relative position of the pressure plate assembly and the support tray unchanged during the welding process.

[0026] According to the positioning fixture for welding insulated gate bipolar transistors provided by this utility model, the locking assembly includes:

[0027] Mounting base, fixed to the support tray;

[0028] The snap-fit ​​body is hinged to the mounting base, and a connecting plate is provided at one end of the snap-fit ​​body away from the mounting base. The connecting plate is fixed to the pressure plate assembly.

[0029] A connecting rod, one end of which is hinged to the mounting base;

[0030] The locking arm has its end hinged to the buckle body and its middle part hinged to the other end of the connecting rod.

[0031] A second aspect of this invention provides a welding apparatus, including a worktable and a positioning fixture for welding insulated gate bipolar transistors as described in any one of the claims, the positioning fixture being fixed to the worktable.

[0032] The positioning fixture for welding insulated gate bipolar transistors provided by this utility model, through the layered rigid connection of the support base plate, support tray and pressure plate assembly, avoids the displacement of the circuit board or IGBT caused by external forces (such as the contact force of the soldering iron tip) during welding, and achieves stable support for the circuit board and precise positioning of the IGBT. It is perfectly adapted to the operation requirements of spot welding machines, ensuring that the program coordinates of the spot welding machine do not need to be adjusted frequently, and batch welding assembly can be realized to improve welding efficiency and quality.

[0033] Meanwhile, multiple first support components and multiple second support components are arranged at intervals, so that the support tray carrying the circuit board is separated from the support base plate by a certain height. This allows for compatibility with double-sided plug-in layout of the circuit board (IGBT and connector, aluminum electrolytic capacitor are distributed on opposite sides). It can adapt to the circuit boards (i.e. power boards) of different models of energy storage inverters without additional adjustment of the tooling structure. It supports batch and standardized welding operations in high power density scenarios and solves the efficiency bottleneck problem caused by the switching of operation surfaces in traditional manual welding.

[0034] The welding equipment provided by this utility model has all the advantages of the aforementioned positioning fixture for welding insulated gate bipolar transistors because it includes the aforementioned positioning fixture for welding insulated gate bipolar transistors. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention.

[0037] Figure 2 This is a left view of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention.

[0038] Figure 3 This is a top view of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention.

[0039] Figure 4 yes Figure 3 Axonometric sectional view along line AA.

[0040] Figure 5 yes Figure 3 Axonometric sectional view along line BB.

[0041] Figure 6 yes Figure 4 Enlarged view of section C.

[0042] Figure 7 This is a partial structural schematic diagram of a positioning fixture for welding insulated gate bipolar transistors provided in an embodiment of this utility model.

[0043] Figure 8 This is a schematic diagram of the structure of an insulated gate bipolar transistor, a pad, and a circuit board.

[0044] Figure label:

[0045] 10. Support base plate; 11. First support component; 12. Second support component; 121. Support sleeve; 122. Support rod; 123. Guide groove; 124. Guide column;

[0046] 20. Supporting tray; 21. Receiving cavity;

[0047] 30. Pressure plate assembly; 31. Positioning plate; 311. First positioning post; 312. Second positioning post; 32. Pressure plate body; 321. Alternating window; 33. Third support component;

[0048] 40. Locking assembly; 41. Mounting base; 42. Buckle body; 43. Linkage rod; 44. Locking arm;

[0049] 50. Circuit board; 60. Insulated gate bipolar transistor; 61. Process hole; 70. Spacer; 71. Threaded hole. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0051] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0052] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] Figure 1 This is a schematic diagram of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention. Figure 2 This is a left view of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention. Figure 3 This is a top view of the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention. Figure 4 yes Figure 3 Axonometric sectional view along line AA. Figure 5 yes Figure 3 Axonometric sectional view along line BB.

[0055] See Figures 1 to 5 This utility model provides a positioning fixture for welding insulated gate bipolar transistors (IGBTs). It is a dedicated positioning fixture for IGBT welding. Its core function is to achieve stable support and precise positioning of the circuit board 50 containing double-sided plug-in components and IGBTs through layered support, elastic clamping and rigid locking. It is adapted to the operation requirements of spot welding machines and solves the problems of low efficiency, unstable quality and welding failure caused by IGBT position fluctuation in traditional manual welding.

[0056] The insulated gate bipolar transistor 60 is soldered to the circuit board 50. A spacer 70 is provided between the circuit board 50 and the insulated gate bipolar transistor 60. The spacer 70 is usually made of elastic or flexible material, such as silicone or plastic, which can serve as a buffer layer to absorb stress, reduce rigid collisions between the device and the circuit board 50, and improve the mechanical stability of the assembly.

[0057] The positioning fixture for welding insulated gate bipolar transistors includes a support base plate 10, a support tray 20, and a pressure plate assembly 30.

[0058] The support base plate 10 is the main load-bearing structure of the positioning fixture, made of steel or alloy. Multiple mounting positions are machined on the upper surface of the support base plate 10 to fix multiple first support members 11 and multiple second support members 12, which are arranged at intervals. Positioning holes are provided on the edges of the support base plate 10 for bolt fixing to an external workbench (such as a spot-welded base) to prevent overall displacement of the positioning fixture. A pre-drilled groove is provided in the central area of ​​the support base plate 10 to reduce weight and facilitate observation of the welding process.

[0059] The first support member 11 and the second support member 12 are both cylindrical support structures, such as stepped shafts or cylinders. The first support member 11 is made of hard aluminum alloy. The bottom of the first support member 11 is fixed to the support base plate 10 by countersunk screws, and the top is machined into a flat surface to directly support the bottom surface of the circuit board 50 (power board) and the bottom of the support tray 20.

[0060] The second support member 12 can be made of polyurethane elastomer. The bottom of the second support member 12 is fixed to the base of the first support member 11 by embedded injection molding (or directly bonded to the support base plate 10), and the top is designed with an arc-shaped concave surface to support the IGBT pad 70 on the circuit board 50. The elastic material can absorb the slight impact when the IGBT is inserted. The second support member 12 can also adopt a rigid structure that can stretch and contract along its own height.

[0061] The support tray 20 is provided with a rectangular receiving cavity 21. Figure 5 As shown in the diagram, the edge of the receiving cavity 21 may be provided with a support flange, and an elastic limiting post is provided on the support flange. When the circuit board 50 is inserted into the receiving cavity 21, the elastic limiting post can be inserted into the process hole 61 of the circuit board 50 (as shown in the diagram). Figure 8 (As shown in the figure), used to limit the translation of the circuit board 50 in the X / Y directions.

[0062] The pressure plate assembly 30 is located above the support tray 20 and is used to apply pressure to the circuit board 50 and to position the insulated gate bipolar transistor 60. A clearance window 321 is provided on the pressure plate assembly 30 at a position corresponding to the pin of the insulated gate bipolar transistor 60. The size of the clearance window 321 matches the movement trajectory of the soldering iron tip. The edges of the clearance window 321 are rounded to avoid obstructing the movement trajectory of the soldering iron tip.

[0063] It should be noted that, without the locking component 40 described below, the pressure plate assembly 30 has a certain weight, which can apply a certain pressure to the circuit board 50 and the insulated gate bipolar transistor 60 on the circuit board 50, ensuring that the position of the pressure plate assembly 30 and the relative position of the support tray 20 remain unchanged.

[0064] It is understood that the positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention, through the layered rigid connection of the support base plate 10, the support tray 20 and the pressure plate assembly 30, avoids the displacement of the circuit board 50 or IGBT caused by external forces (such as the contact force of the soldering iron tip) during welding, and achieves stable support for the circuit board 50 and precise positioning of the IGBT. It perfectly adapts to the operation requirements of the spot welding machine, ensures that the program coordinates of the spot welding machine do not need to be frequently adjusted, and enables batch welding assembly to improve welding efficiency and quality.

[0065] Meanwhile, multiple first support members 11 and multiple second support members 12 are arranged at intervals, so that the support tray 20 carrying the circuit board 50 is spaced at a certain height from the support base plate 10. This allows for compatibility with the double-sided plug-in layout of the circuit board 50 (IGBTs and connectors, aluminum electrolytic capacitors are distributed on opposite sides). It can adapt to the circuit board 50 (i.e., power board) of different models of energy storage inverters without additional adjustment of the tooling structure. It supports batch and standardized welding operations in high power density scenarios and solves the efficiency bottleneck problem caused by the switching of operation surfaces in traditional manual welding.

[0066] Continue reading Figure 2 In some embodiments of this utility model, the second support member 12 includes a cylindrical support sleeve 121, an elastic member, and a cylindrical support rod 122.

[0067] The support sleeve 121 is fixed to the support base plate 10 by fasteners such as countersunk bolts; an elastic element, which can be a spring, is embedded inside the support sleeve 121. The support rod 122 is fitted inside the support sleeve 121, with one end abutting against the elastic element and the other end abutting against the pad 70. This arrangement achieves elastic buffer support and adaptive positioning for the IGBT pad 70.

[0068] When the IGBT is inserted into the circuit board 50 (power board), the spacer 70 and the support may experience momentary impact due to operational errors or equipment vibration (such as collisions during insertion). By embedding an elastic element (spring) inside the support sleeve 121, when the spacer 70 is subjected to impact or vibration, the support sleeve rod 122 will compress the spring, absorbing energy through the elastic deformation of the spring, preventing rigid impact from being directly transmitted to the circuit board 50 or the IGBT body, and reducing the risk of component damage.

[0069] In addition, the height of the IGBT pad 70 may have manufacturing tolerances, or the actual height of the pad 70 may deviate from the design value due to welding deformation of the circuit board 50. If a rigid support is used, the IGBT may tilt or fail to fit against the pressure plate due to height mismatch. Therefore, the compressibility of the spring allows the support sleeve 122 to move axially (vertically) within the sleeve, automatically adjusting the vertical position of the pad 70 to compensate for height deviations, ensuring uniform contact between the lower surface of the pressure plate assembly 30 and the circuit board 50 and the IGBT, and avoiding uneven clamping force caused by local suspension.

[0070] Furthermore, a buffer pad can be provided at the other end of the support sleeve 122, which abuts against the pad 70. Since the support sleeve 122 and the pad 70 will generate high-frequency impact force due to instantaneous rigid collision, the buffer pad (such as rubber, polyurethane, or other elastic materials) can absorb part of the impact energy through its own elastic deformation, converting the instantaneous peak force into a slowly released elastic force. This prevents the support sleeve 122 or the pad 70 from cracking or deforming due to repeated impacts, thereby extending their service life.

[0071] Continue reading Figure 2 In some embodiments of this utility model, one of the support sleeve 121 and the support rod 122 is provided with a guide member along the axial direction, and the other of the support sleeve 121 and the support rod 122 is provided with a mating member, which slides with the guide member for guiding.

[0072] That is, the guide member can be set on the support sleeve 121 or on the support rod 122. Correspondingly, when the guide member is set on the support sleeve 121, the mating member is set on the support rod 122. When the guide member is set on the support rod 122, the mating member is set on the support sleeve 121.

[0073] This configuration constrains the movement direction of the support sleeve 122 within the support sleeve 121, ensuring that it moves only axially (vertically) during elastic expansion and contraction, avoiding skew or radial sway, thereby improving the stability of the elastic buffer and the accuracy of the IGBT support.

[0074] Specifically, the guide member includes a guide groove 123 that extends axially along the support sleeve 122; the mating member includes at least one guide post 124, the line connecting the center points of the at least one guide post 124 is parallel to the axis of the guide groove 123. For example, the guide post 124 is a stud, and the mating member includes at least one stud, but two or three studs may also be provided. The line connecting the center points of the two or three studs is parallel to the axis of the guide groove 123. At least one guide post 124 is spaced apart on the support sleeve 121 and extends into the interior of the guide groove 123.

[0075] This configuration ensures the stability of the support sleeve 122's axial movement, the accuracy of the pad 70's support position, and improves the welding qualification rate of the spot welding machine. Simultaneously, it ensures the controllability of the spring compression, resulting in more uniform elastic force output and preventing fluctuations in IGBT clamping force caused by unstable buffering force.

[0076] Figure 6 yes Figure 4 Enlarged view of section C. Figure 7 This is a partial structural schematic diagram of a positioning fixture for welding insulated gate bipolar transistors provided in an embodiment of this utility model. Figure 8 This is a schematic diagram of the structure of the insulated gate bipolar transistor 60, the pad 70, and the circuit board 50.

[0077] See Figures 6 to 8 In some embodiments of this utility model, the pressure plate assembly 30 includes a positioning plate 31 and a pressure plate body 32. The positioning plate 31 is provided with a first positioning post 311 and a second positioning post 312. The first positioning post 311 is used to insert into the threaded hole 71 of the pad 70, and the second positioning post 312 is used to insert into the process hole 61 of the insulated gate bipolar transistor 60 itself. The pressure plate body 32 is pressed onto the positioning plate 31, and the IGBT, pad 70, and circuit board 50 are tightly bonded together by mechanical pressure.

[0078] After the IGBT is soldered, the spacer 70 is fixed to the housing by countersunk bolts or screws. Therefore, the threaded hole 71 on the spacer 70 is a countersunk hole. The support sleeve 122 abuts against the bottom wall of the countersunk hole to support the spacer 70 from below, lifting the entire spacer 70 and preventing the IGBT from tilting down. After the first positioning pin 311 is inserted into the threaded hole 71 of the spacer 70, the position of the spacer 70 is fixed on the preset coordinates of the circuit board 50.

[0079] The process hole 61 of the IGBT itself can be a mounting hole on the heat sink or a positioning hole next to the pin. After the second positioning post 312 is inserted into the process hole 61, it directly restricts the X / Y axis displacement of the IGBT body, ensuring that the relative position of the IGBT pin and the solder pad of the circuit board 50 matches the coordinate reference of the spot welding machine program.

[0080] The second positioning post 312 is symmetrically arranged with the center of the first positioning post 311 as the center of symmetry. When the IGBT rotates slightly due to external force (such as insertion deviation), the second positioning post 312 will contact the edge of the IGBT process hole 61, generating a reverse resistance torque to force the IGBT to return to the correct position and avoid the pin and pad from being loosely connected due to tilt.

[0081] During spot welding, the soldering iron tip applies a certain contact force to the IGBT pins. If the IGBT is not reliably pressed, it may tilt upwards (float) due to the reaction force, resulting in poor contact between the pins and the pads (cold solder joint). The pressure plate body 32 applies downward pressure by its own weight (or an additional elastic pressure head) to press the IGBT, pad 70, and power board into a whole, eliminating the risk of floating.

[0082] The clearance window 321 is located on the pressure plate body 32, corresponding to the pin of the insulated gate bipolar transistor 60, providing unobstructed movement space for the soldering iron tip of the spot welding machine. The edges of the clearance window 321 can be designed with rounded corners, which can be used with an industrial camera to monitor the alignment of the soldering iron tip with the pin in real time, assisting in adjusting the welding trajectory (such as X / Y axis fine adjustment), and further improving the accuracy of the welding position.

[0083] Continue reading Figure 2 and Figure 5 In some embodiments of this utility model, the positioning fixture for welding insulated gate bipolar transistors further includes a third support member 33, which is located between the plane of the pressure plate body 32 and the support tray 20.

[0084] Since the pressure plate body 32 needs to apply pressure to the IGBT and circuit board 50, and the support tray 20 bears the weight of the circuit board 50 and IGBT, if there is no additional support between the two, long-term pressure or welding thermal stress can easily cause the middle of the pressure plate body 32 to dent, resulting in uneven distribution of pressure force. At the same time, the support tray 20 may warp due to the weight of the circuit board 50 and IGBT and the thermal expansion from welding, which may damage its fit with the circuit board 50.

[0085] The pressure plate body 32 and the support tray 20 are rigidly connected by the third support member 33, forming a support beam structure between the two. This can effectively disperse the concentrated pressure of the pressure plate body 32 and suppress the warping deformation of the support tray 20, ensuring the overall flatness of the tooling.

[0086] Furthermore, if there are multiple gaps between the pressure plate body 32 and the support tray 20, these gaps will cause uneven clamping force and reduce clamping efficiency. By setting a third support member 33 between the pressure plate body 32 and the support tray 20, the support points can be evenly distributed, and the pressure of the pressure plate body 32 can be evenly transmitted to the support tray 20, ensuring the uniform distribution of clamping force on the surface of the circuit board 50 and avoiding local over- or under-pressure.

[0087] Furthermore, in mass production, the positioning fixture needs to be used repeatedly, and the elastic deformation of the pressure plate body 32 or the wear of the support tray 20 will cause a decrease in the parallelism between the pressure plate body 32 and the support tray 20. Therefore, by setting a support column of fixed height between the pressure plate body 32 and the support tray 20, the parallelism between the two can be maintained for a long time, ensuring the repeatability of the positioning fixture.

[0088] Furthermore, the third support member 33 is detachably connected to the pressure plate body 32, and the side of the third support member 33 away from the pressure plate body 32 abuts against the support tray 20 and the circuit board 50.

[0089] This configuration allows the third support 33 to form an integral structure with the pressure plate body 32, preventing parts from being lost. At the same time, when the third support 33 wears or is damaged due to long-term use, it is not necessary to disassemble the entire pressure plate body 32; only the damaged third support 33 needs to be replaced. This avoids the scrapping of the entire tooling due to a local failure and reduces maintenance costs.

[0090] Continue reading Figure 1 In some embodiments of this utility model, the positioning fixture for welding insulated gate bipolar transistors includes a support base plate 10, a support tray 20, and a pressure plate assembly 30, as well as a locking assembly 40. The locking assembly 40 is connected to the support tray 20 and the pressure plate assembly 30 respectively, and is used to fix the relative position of the pressure plate assembly 30 and the support tray 20, so as to ensure that the relative position of the pressure plate assembly 30 and the support tray 20 remains unchanged during the welding process.

[0091] Furthermore, the locking assembly 40 includes a mounting base 41, a snap-fit ​​body 42, a connecting rod 43, and a locking arm 44.

[0092] The mounting base 41 is fixed to the support tray 20 by bolts or other fasteners; the snap fastener body 42 is hinged to the mounting base 41, and a connecting plate is provided at one end of the snap fastener body 42 away from the mounting base 41. The connecting plate is fixed to the pressure plate assembly 30. One end of the connecting rod 43 is hinged to the mounting base 41; the end of the locking arm 44 is hinged to the snap fastener body 42, and the middle part is hinged to the other end of the connecting rod 43.

[0093] When the locking assembly 40 is in the unlocked state, the snap-fit ​​body 42 is raised upward around one hinge point of the mounting base 41, forming a certain angle with the support tray 20. At this time, the connecting plate fixed to the pressure plate assembly 30 does not apply pressure to the pressure plate body 32. One end of the connecting rod 43 is connected to another hinge point of the mounting base 41, and the other end of the connecting rod 43 is connected to the middle part of the locking arm 44, and is in a relaxed state. The locking arm 44 is in a natural hanging state and does not constrain the snap-fit ​​body 42.

[0094] When it is necessary to fix the pressure plate assembly 30, press down on the buckle body 42 to make the buckle body 42 rotate around the fulcrum. As the buckle body 42 rotates around the fulcrum, the end of the buckle body 42 connected to the pressure plate assembly 30 moves downward, causing the connecting plate to apply downward pressure to the pressure plate assembly 30. When the buckle body 42 rotates, its end pulls the end of the locking arm 44 downward, and the locking arm 44 rotates around the node. When the locking arm 44 rotates, the connecting rod 43 is stretched, generating a reverse elastic force, which pushes the node of the locking arm 44 to move towards the fulcrum, further amplifying the constraint force of the locking arm 44 on the buckle body 42.

[0095] The locking assembly 40 provided in this embodiment uses the mechanical self-locking principle to convert the external driving force into a lasting mechanical constraint force, ensuring that the pressure plate assembly 30 does not loosen during the welding process, thereby improving the welding quality of IGBTs.

[0096] The positioning fixture for welding insulated gate bipolar transistors provided in this embodiment of the present invention is assembled by first fixing the support base plate 10 on the worktable of the spot welding machine, and fixing the support tray 20 on the top of the first support member 11 with screws; then assembling the circuit board 50, first placing the IGBT pad 70 on the circuit board 50, then placing the IGBT, and finally placing the positioning plate 31 to fix the relative position of the IGBT and the positioning plate 31, then placing the assembled circuit board 50 on the support tray 20, and then fastening the pressure plate assembly 30 and locking the locking assembly 40 to achieve the locking function.

[0097] This utility model embodiment also provides a welding device, which includes a worktable and any of the positioning fixtures for welding insulated gate bipolar transistors, the positioning fixture being fixed to the worktable.

[0098] It is understandable that, since the welding equipment includes the aforementioned positioning fixture for welding insulated gate bipolar transistors, it possesses all the advantages of the aforementioned positioning fixture for welding insulated gate bipolar transistors.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A positioning fixture for soldering insulated-gate bipolar transistors (IGBTs), wherein the IGBT is soldered to a circuit board, and a spacer is provided between the circuit board and the IGBT, characterized in that, include: A supporting base plate is provided with a plurality of first supporting members and a plurality of second supporting members, which are spaced apart; the plurality of first supporting members are used to support the circuit board, and the plurality of second supporting members are used to support the pad block; A support tray is mounted on the first support member, and the support tray is provided with a receiving cavity for embedding the circuit board; A pressure plate assembly, located above the support tray, is used to apply pressure to the circuit board and to position the insulated gate bipolar transistor. The pressure plate assembly has a clearance window at a position corresponding to the pin of the insulated gate bipolar transistor, and the size of the clearance window matches the movement trajectory of the soldering iron tip.

2. The positioning fixture for welding insulated-gate bipolar transistors according to claim 1, characterized in that, The second support member includes: A support sleeve is provided on the support base plate; An elastic element is embedded inside the support sleeve; A support sleeve rod is fitted inside the support sleeve, with one end of the support sleeve rod abutting against the elastic element and the other end of the support sleeve rod abutting against the pad block.

3. The positioning fixture for welding insulated-gate bipolar transistors according to claim 2, characterized in that, One of the support sleeve and the support rod is provided with a guide member along the axial direction, and the other of the support sleeve and the support rod is provided with a mating member, which slides with the guide member for guiding.

4. The positioning fixture for welding insulated-gate bipolar transistors according to claim 3, characterized in that, The guide member includes a guide groove that extends axially along the support sleeve. The mating component includes at least one guide post, which is spaced apart on the support sleeve and extends into the interior of the guide groove.

5. The positioning fixture for welding insulated-gate bipolar transistors according to claim 1, characterized in that, The pressure plate assembly includes: A positioning plate is provided with a first positioning post and a second positioning post. The first positioning post is used to be inserted into the threaded hole of the pad, and the second positioning post is used to be inserted into the process hole of the insulated gate bipolar transistor itself. The pressure plate body is pressed onto the positioning plate; The clearance window is located on the pressure plate body and at a position corresponding to the pin of the insulated gate bipolar transistor.

6. The positioning fixture for welding insulated-gate bipolar transistors according to claim 5, characterized in that, It also includes a third support member, which is located between the plane of the pressure plate body and the support tray.

7. The positioning fixture for welding insulated-gate bipolar transistors according to claim 6, characterized in that, The third support member is detachably connected to the pressure plate body, and the side of the third support member away from the pressure plate body abuts against the support tray and the circuit board.

8. The positioning fixture for welding insulated-gate bipolar transistors according to any one of claims 1 to 7, characterized in that, Also includes: A locking assembly is connected to the support tray and the pressure plate assembly respectively, and is used to fix the support tray and the pressure plate assembly so as to keep the relative position of the pressure plate assembly and the support tray unchanged during the welding process.

9. The positioning fixture for welding insulated-gate bipolar transistors according to claim 8, characterized in that, The locking assembly includes: Mounting base, fixed to the support tray; The snap-fit ​​body is hinged to the mounting base, and a connecting plate is provided at one end of the snap-fit ​​body away from the mounting base. The connecting plate is fixed to the pressure plate assembly. A connecting rod, one end of which is hinged to the mounting base; The locking arm has its end hinged to the buckle body and its middle part hinged to the other end of the connecting rod.

10. A welding device, characterized in that, The device includes a worktable and a positioning fixture for welding insulated gate bipolar transistors as described in any one of claims 1 to 9, the positioning fixture being fixed to the worktable.

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