A soldering fixture for a power module copper clad ceramic substrate (DBC)

Abstract

The application relates to the technical field of welding jigs, and proposes a welding jig for a copper-clad ceramic substrate (DBC) of a power module, which has the advantages that the structure is simple, multiple DBCs can be simultaneously welded, the production efficiency is higher, heat conduction is more uniform, problems such as a solder layer cavity and DBC warping can be better reduced, the welding process quality of the power module is greatly improved, the matched jig structure forms a structure for operation control, the operation convenience is higher, the functionality is stronger, and the welding jig is more practical, comprising a jig body and a bearing base, the jig body comprises an upper cover plate, a lower cover plate, a positioning plate, a copper-clad ceramic substrate, a bottom supporting plate, a large pressing block and a small pressing block, the large pressing block and the small pressing block are both installed on the lower cover plate, the bottom supporting plate is provided with multiple DBC positioning grooves and four bottom plate bolt through holes, the multiple DBC positioning grooves are used for the auxiliary positioning of the copper-clad ceramic substrate, the positioning plate is provided with two positioning bosses, the lower cover plate is provided with two lower cover positioning grooves and multiple pressing block positioning holes.

Description

Technical Field

[0001] This invention relates to the field of welding fixture technology, and more specifically to a welding fixture for copper-clad ceramic substrates (DBC) of power modules. Background Technology

[0002] Research shows that as a core component of power conversion and control, soldering accounts for a significant portion of the reliability issues of power modules. Solder layer failures during the packaging process account for 34% of the power conversion system failures. In addition, problems such as solder spatter, solder voids, and solder layer cracks are easily formed during the soldering process. After reflow, the copper-clad ceramic substrate (DBC) of the module will also generate large residual stress and warping. All of these phenomena reduce the quality of the soldering process and affect the reliability and service life of the module. To improve the soldering quality of the copper-clad ceramic substrate of power modules, we propose a soldering fixture for the copper-clad ceramic substrate (DBC) of power modules.

[0003] A search revealed that Chinese patent application CN202220145808.9 discloses a guiding fixture and guiding device, which is generally described as including a first body and a second body. The first body includes a first base and at least one first guiding part, the first guiding part having a first guiding surface. A receiving space is provided between the second body and the first body for placing a copper-clad ceramic plate. The first guiding part extends from the first base to the second body, and the first guiding surface is used to contact and guide the copper-clad ceramic plate downward. Chinese patent application CN202122339294.9 discloses a device for welding ceramic sheets, which is generally described as… It includes a base, a bracket, a first slide rail, a second slide rail, a resistance welding base, a resistance welding head, a temperature control module, and a nitrogen outlet. The first slide rail is set on the upper surface of the base, and a moving plate is slidably connected to the first slide rail. A fixture and a welding platform are installed on the front side of the moving plate. A transmission module is electrically connected to one side of the moving plate, and the resistance welding base is connected to the transmission module. The resistance welding head is set at the bottom of the resistance welding base, and the temperature control module is electrically connected to the surface of the resistance welding head. The bottom of the resistance welding base also has a nitrogen outlet. During use, the temperature control module can quickly heat up the resistance welding head to facilitate welding, and the moving plate can be moved to a new position by pressing the start button and then automatically reset.

[0004] The two existing technical solutions mentioned above differ in that the former's core is a guiding fixture, which only contains a single guiding structure. In practical applications, the target component for guiding and limiting is relatively simple, and the part concerning the mutual mold closing and separation operation between the first and second main bodies is minimal. The latter's core is a welding functional component, and the description of the corresponding fixture is relatively simple. Therefore, both solutions require further functional enrichment. Furthermore, during the welding process, since reflow soldering uses a bottom plate heating method, the uneven heat conduction of traditional welding fixtures can easily cause cold solder joints and voids in the solder layer. In addition, passive components such as chips and resistors are small in size and light in weight, and are easily affected by the hot air of the soldering furnace during welding, causing positional displacement, which in turn increases the parasitic inductance and parasitic capacitance of the module. In severe cases, this can affect the dynamic and static parameters of the module. Traditional fixtures do not consider using pressure blocks to maintain a tight fit between passive components such as chips and the DBC, or using the fixture's own weight to press on the upper surface of the passive components, which can cause severe solder overflow. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a welding fixture for copper-clad ceramic substrates (DBCs) in power modules. The fixture has a simple structure and can simultaneously weld passive components on multiple DBCs, greatly increasing production efficiency. The tight fit between the various parts of the fixture body ensures the accuracy of the relative positions of the passive components and solder pads in the DBC welding process. During the welding process, the fixture body has more uniform heat conduction, which can effectively reduce problems such as solder layer voids and DBC warping, greatly improving the welding process quality of power modules. Furthermore, the fixture structure forms an operation control structure, which is more convenient to operate, more functional, and more practical.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a welding fixture for copper-clad ceramic substrates (DBC) of power modules, comprising a fixture body and a copper-clad ceramic substrate, and further comprising a support base. The fixture body includes an upper cover plate, a lower cover plate, a positioning plate, a bottom support plate, a large pressure block, and a small pressure block. The large pressure block and the small pressure block are both mounted on the lower cover plate. The bottom support plate has multiple DBC positioning grooves and four bottom plate bolt through holes. The multiple DBC positioning grooves are used for auxiliary positioning of the copper-clad ceramic substrate. The positioning plate is provided with two positioning bosses. The lower cover plate is provided with two lower cover positioning grooves and multiple pressure block positioning holes. The upper cover plate is provided with two upper cover positioning grooves. The two lower cover positioning grooves are respectively matched with the two positioning bosses, and the two upper cover positioning grooves are respectively matched with the two positioning bosses. The upper cover plate, the lower cover plate, and the positioning plate are mounted on the support base via an active drive assembly. The bottom support plate is mounted on the support base via a vertical bracket.

[0007] Preferably, the active drive assembly includes a rear conveyor belt and a track adjustment frame. The rear conveyor belt is mounted on the bearing base, and the track adjustment frame is connected to the upright support. Three progressive support plates are fixedly connected to the outside of the rear conveyor belt. Each of the three progressive support plates is connected to a progressive clamping frame via an elastic component. Each of the three progressive clamping frames is rotatably connected to an inner bushing. Each of the three inner bushings is fixedly connected to a transmission column, and each of the three transmission columns is matched with the track adjustment frame. An upper connecting frame, a lower connecting frame, and a positioning connecting frame are fixedly connected to the outside of the three inner bushings, respectively. The upper connecting frame, the lower connecting frame, and the positioning connecting frame are fixedly connected to the upper cover plate, the lower cover plate, and the positioning plate, respectively.

[0008] Preferably, the track adjustment frame is provided with a lower horizontal track and an upper vertical track, and the lower horizontal track and the upper vertical track are connected by a torsion track. The lower horizontal track, the upper vertical track and the torsion track are all matched with the transmission column.

[0009] Preferably, the three progressive clamping frames each include a primary slot frame, a secondary slot frame, and a tertiary slot frame, which are arranged sequentially from top to bottom. The primary slot frame, secondary slot frame, and tertiary slot frame are respectively fixedly connected to a primary pressure frame, a secondary pressure frame, and a tertiary pressure frame. Each of the primary slot frame, secondary slot frame, tertiary slot frame, primary pressure frame, secondary pressure frame, and tertiary pressure frame is provided with a semi-annular groove that matches the inner liner.

[0010] Preferably, a primary guide sleeve is fixedly connected between the primary slot frame and the primary pressure frame; a secondary guide sleeve is fixedly connected between the secondary slot frame and the secondary pressure frame; and a tertiary guide sleeve is fixedly connected between the tertiary slot frame and the tertiary pressure frame. The primary, secondary, and tertiary guide sleeves are slidably connected to primary, secondary, and tertiary guide prisms, respectively. The primary, secondary, and tertiary guide prisms are fixedly connected to three progressive support plates. Primary, secondary, and tertiary springs are fixedly connected to the three progressive support plates, respectively. The primary, secondary, and tertiary springs are respectively fitted over the primary, secondary, and tertiary guide prisms, and are fixedly connected to the primary, secondary, and tertiary guide sleeves, respectively.

[0011] Preferably, a fixed side frame is fixedly connected to the support base, and an assembly side frame is installed on the support base. A drive pulley and a transmission pulley are rotatably installed on the fixed side frame. The rear conveyor belt is driven between the drive pulley and the transmission pulley. A servo motor is installed outside the fixed side frame, and the output shaft of the servo motor is drivenly connected to the drive pulley. The assembly side frame is provided with two rotating support holes, which are respectively matched with the drive pulley and the transmission pulley.

[0012] Preferably, a track frame is fixedly connected to the bearing base, and a track sleeve is provided on the assembly side frame. The track sleeve matches the track frame, and multiple threaded holes are provided on the track sleeve. Positioning bolts for pressing and positioning the track sleeve relative to the track frame are threaded into the multiple threaded holes.

[0013] Preferably, the top of the support frame is provided with a support frame, and a mounting slot plate is fixedly connected to the support frame by pressing bolts. All four bolt through holes of the base plate are provided with hexagonal socket head cap screws, and all four hexagonal socket head cap screws are threaded to the mounting slot plate. An insertion bracket is fixedly connected to the rear side of the support frame, and the insertion bracket has an insertion hole for inserting the track adjustment frame. An external assembly frame is fixedly connected to the right end of the support frame.

[0014] Preferably, a middle support is fixedly connected to the bearing base. The middle support is provided with a bottom insertion positioning groove and a top insertion positioning hole. Both the bottom insertion positioning groove and the top insertion positioning hole are matched with the track adjustment frame. The top insertion positioning hole is provided with a screw hole, and a clamping bolt matching the track adjustment frame is provided in the screw hole.

[0015] Preferably, the positioning plate is provided with two positioning bolt through holes, the lower cover plate is provided with two lower cover bolt through holes, and the upper cover plate is provided with two upper cover bolt through holes. The positioning bolt through holes are internally threaded with positioning clamping bolts that match the positioning connecting bracket, the upper cover bolt through holes are internally threaded with upper clamping bolts that match the upper connecting bracket, and the lower cover bolt through holes are internally threaded with lower clamping bolts that match the lower connecting bracket.

[0016] Compared with the prior art, the present invention provides a welding fixture for copper-clad ceramic substrates (DBC) of power modules, which has the following advantages:

[0017] (1) In this invention, the design of the fixture body is matched with the copper-clad ceramic substrate of the power module to form a corresponding welding fixture. The structure is simple and can weld passive devices on multiple DBCs at the same time, which greatly increases production efficiency. The close fit between the various parts of the fixture body ensures the accuracy of the relative position of the passive devices and solder pads of the copper layer of the DBC. During the welding process, the heat conduction of the fixture body is more uniform, which can better reduce the problems of solder layer voids and DBC warping, and greatly improve the welding process quality of the power module.

[0018] (2) In this invention, through the design of the active drive component, the upper cover plate, lower cover plate and positioning plate in the matching fixture body form a matching installation and power operation structure, which can realize the corresponding installation of the matching fixture body relative to the bottom support plate, and also facilitate the opening and closing drive control of the fixture body, making it more convenient to operate, more functional and more practical. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the entire invention;

[0020] Figure 2 For the present invention Figure 1 A magnified schematic diagram of the local structure at point A;

[0021] Figure 3 This is a three-dimensional structural diagram of the cooperation between the support base, fixed side frame, and drive pulley of the present invention;

[0022] Figure 4 This is a three-dimensional structural diagram of the bracket and clamping bolt assembly in this invention;

[0023] Figure 5 This is a three-dimensional structural diagram showing the disassembled body of the fixture of the present invention;

[0024] Figure 6 This is a three-dimensional structural diagram of the large pressing block of the present invention;

[0025] Figure 7 This is a three-dimensional structural diagram of the small pressing block of the present invention;

[0026] Figure 8 This is a three-dimensional structural diagram of a copper-clad ceramic substrate according to the present invention;

[0027] Figure 9 This is a rear-view perspective three-dimensional structural diagram of the entire invention;

[0028] Figure 10 For the present invention Figure 9 A magnified view of the structure at point B in the middle;

[0029] Figure 11 This is a three-dimensional structural diagram of the present invention after the upper cover plate, lower cover plate, and positioning plate are all raised relative to the bottom support plate.

[0030] Figure 12 For the present invention Figure 11 A magnified schematic diagram of the local structure at point C;

[0031] Figure 13 This is a three-dimensional structural diagram of the present invention, showing the upper cover plate, lower cover plate, and positioning plate all rising relative to the base plate after being moved and raised.

[0032] Figure 14 For the present invention Figure 13 A magnified schematic diagram of the local structure at point D;

[0033] Figure 15 This is a three-dimensional structural diagram showing the combination of the primary pressure frame, secondary pressure frame, and tertiary pressure frame of the present invention.

[0034] In the diagram: 1. Top cover plate; 2. Large pressure block; 3. Small pressure block; 4. Lower cover plate; 5. Positioning plate; 6. Copper-clad ceramic substrate; 7. Base plate; 8. DBC positioning groove; 9. Bottom plate bolt through hole; 10. Positioning bolt through hole; 11. Positioning boss; 12. Lower cover bolt through hole; 13. Lower cover positioning groove; 14. Pressure block positioning hole; 15. Top cover bolt through hole; 16. Top cover positioning groove; 17. Bearing base; 18. Vertical support; 19. Rear conveyor belt; 20. Track adjustment frame; 21. Progressive support plate; 22. Inner bushing; 23. Transmission column; 24. Upper connecting frame; 25. Lower connecting frame; 26. Positioning connecting frame; 27. Lower transverse track; 28. Upper longitudinal track; 29. ​​Torsional track; 30. Primary slot frame; 31. Secondary slot frame; 32. Tertiary slot frame; 33. Primary pressure frame; 34. Secondary... 35. Level 1 pressure frame; 36. Level 2 pressure frame; 37. Semi-annular groove; 38. Level 1 guide sleeve; 39. Level 2 guide sleeve; 40. Level 1 guide prism; 41. Level 2 guide prism; 42. Level 3 guide prism; 43. Level 1 sleeve spring; 44. Level 2 sleeve spring; 45. Level 3 sleeve spring; 46. Fixed side frame; 47. Assembly side frame; 48. Drive pulley; 49. Transmission pulley; 50. Servo motor; 51. Rotating support hole; 52. Track frame; 53. Track sleeve; 54. Positioning bolt; 55. Support frame; 56. Mounting slot plate; 57. Insertion bracket; 58. Insertion hole; 59. External assembly frame; 60. Middle bracket; 61. Bottom insertion positioning groove; 62. Top insertion positioning hole; 63. Clamping bolt; 64. Positioning and pressing bolt; 65. Upper pressing bolt; 66. Lower pressing bolt. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] For examples, please refer to Figures 1-15A welding fixture for copper-clad ceramic substrates (DBC) of power modules includes a fixture body and a copper-clad ceramic substrate 6, and a support base 17. The fixture body includes an upper cover plate 1, a lower cover plate 4, a positioning plate 5, a bottom support plate 7, a large pressure block 2, and a small pressure block 3. The large pressure block 2 and the small pressure block 3 are both mounted on the lower cover plate 4. The bottom support plate 7 has multiple DBC positioning grooves 8 and four bottom plate bolt through holes 9. The multiple DBC positioning grooves 8 are used for auxiliary positioning of the copper-clad ceramic substrate 6. The positioning plate 5 is provided with two positioning bosses 11. The lower cover plate 4 is provided with two lower cover positioning grooves 13 and multiple pressure block positioning holes 14. The upper cover plate 1 is provided with two upper cover positioning grooves 16. The two lower cover positioning grooves 13 respectively match the two positioning bosses 11. The upper cover positioning groove 16 matches the two positioning protrusions 11 respectively. Through the design of the fixture body, the matching power module copper-clad ceramic substrate 6 forms a corresponding welding fixture. The structure is simple and can weld passive devices on multiple DBCs at the same time, which greatly increases production efficiency. The tight fit between the various parts of the fixture body ensures the accuracy of the relative position of the passive devices and solder pads of the copper layer of the DBC. During the welding process, the heat conduction of the fixture body is more uniform, which can better reduce problems such as solder layer voids and DBC warping, and greatly improve the welding process quality of the power module. The bottom support plate 7 is installed on the bearing base 17 through the upright bracket 18, which provides a support structure for the bottom support plate 7, making it convenient for the bottom support plate 7 to have the stability of the relative position and the rationality of the spatial height.

[0037] It should be further explained that the upper cover plate 1, the lower cover plate 4, and the positioning plate 5 are mounted on the support base 17 via an active drive assembly. The active drive assembly includes a rear conveyor belt 19 and a track adjustment frame 20. The rear conveyor belt 19 is mounted on the support base 17, and the track adjustment frame 20 is connected to the upright support 18. Three progressive support plates 21 are fixedly connected to the outside of the rear conveyor belt 19. Each of the three progressive support plates 21 is connected to a progressive clamping frame via an elastic component. That is, each of the three progressive support plates 21 is equipped with an elastic component, and each of the three elastic components is connected to a progressive clamping frame. Each of the three progressive clamping frames is rotatably connected to an inner bushing 22. Each of the three inner bushings 22 is fixedly connected to a transmission column 23. Each of the three transmission columns 23 is matched with the track adjustment frame 20. The upper connecting frame 24, lower connecting frame 25, and positioning connecting frame 26 are fixedly connected to the outside. The upper connecting frame 24, lower connecting frame 25, and positioning connecting frame 26 are fixedly connected to the upper cover plate 1, lower cover plate 4, and positioning plate 5, respectively. The track adjustment frame 20 is provided with a lower horizontal track 27 and an upper vertical track 28. The lower horizontal track 27 and the upper vertical track 28 are connected by a torsion track 29. The lower horizontal track 27, upper vertical track 28, and torsion track 29 are all matched with the transmission column 23. The three progressive clamping frames include a first-stage slot frame 30, a second-stage slot frame 31, and a third-stage slot frame 32. The first-stage slot frame 30, the second-stage slot frame 31, and the third-stage slot frame 32 are arranged sequentially from top to bottom. The first-stage slot frame 30, the second-stage slot frame 31, and the third-stage slot frame 32 are fixedly connected to a first-stage pressure frame 33. The secondary pressure frame 34 and the tertiary pressure frame 35, the primary slot frame 30, the secondary slot frame 31, the tertiary slot frame 32, the primary pressure frame 33, the secondary pressure frame 34, and the tertiary pressure frame 35 are all provided with semi-annular grooves 36 that match the inner liner 22. A primary guide sleeve 37 is fixedly connected between the primary slot frame 30 and the primary pressure frame 33. A secondary guide sleeve 38 is fixedly connected between the secondary slot frame 31 and the secondary pressure frame 34. A tertiary guide sleeve 39 is fixedly connected between the tertiary slot frame 32 and the tertiary pressure frame 35. A primary guide prism 40, a secondary guide prism 41, and a tertiary guide prism 42 are slidably connected to the primary guide sleeve 37, the secondary guide sleeve 38, and the tertiary guide sleeve 39, respectively. The primary guide prism 40, the secondary guide prism 41, and the tertiary guide prism 42 are respectively connected to three progressive supports. Plate 21 is fixedly connected, and three progressive support plates 21 are respectively fixedly connected with a first-stage spring 43, a second-stage spring 44, and a third-stage spring 45. The first-stage spring 43, the second-stage spring 44, and the third-stage spring 45 are respectively fitted outside the first-stage guide prism 40, the second-stage guide prism 41, and the third-stage guide prism 42. The first-stage spring 43, the second-stage spring 44, and the third-stage spring 45 are respectively fixedly connected to the first-stage guide sleeve 37, the second-stage guide sleeve 38, and the third-stage guide sleeve 39. Through the design of the active drive component, the upper cover plate 1, the lower cover plate 4, and the positioning plate 5 in the matching fixture body form a matching installation and power operation structure, which can realize the corresponding installation of the matching fixture body relative to the bottom support plate 7, and also facilitate the opening and closing drive control of the fixture body, making operation more convenient.It is more functional and more practical.

[0038] Furthermore, a fixed side frame 46 is fixedly connected to the support base 17, and an assembly side frame 47 is installed on the support base 17. A drive pulley 48 and a transmission pulley 49 are rotatably mounted on the fixed side frame 46. A rear conveyor belt 19 is driven between the drive pulley 48 and the transmission pulley 49. A servo motor 50 is installed outside the fixed side frame 46, and the output shaft of the servo motor 50 is drivenly connected to the drive pulley 48. The assembly side frame 47 is provided with two rotating support holes 51, which are respectively matched with the drive pulley 48 and the transmission pulley 49. A track frame 52 is fixedly connected to the support base 17, and a track sleeve 53 is provided on the assembly side frame 47. The track sleeve 53 matches the track frame 52. The support frame 53 has multiple threaded holes, each threaded with a positioning bolt 54 for pressing and positioning the track sleeve 53 relative to the track frame 52. A support frame 55 is located at the top of the support frame 18. A mounting slot plate 56 is fixedly connected to the support frame 55 via pressing bolts. Four hexagonal socket head cap screws are installed in the four base plate bolt through holes 9, and each hexagonal socket head cap screw is threaded into the mounting slot plate 56. An insertion bracket 57 is fixedly connected to the rear side of the support frame 55. The insertion bracket 57 has an insertion hole 58 for inserting the track adjustment bracket 20. An external assembly frame 59 is fixedly connected to the right end of the support frame 55 to facilitate the installation of welding tools. When the corresponding welding operation is manual welding, the external assembly frame 59 can be used to mount the welding tools. The support frame 9 is equipped with a support bracket for placing or supporting the welding torch, facilitating the placement of the welding torch during breaks in manual welding operations. When the welding operation is automated, it also provides a necessary fixed installation position for welding robots. A middle support 60 is fixedly connected to the support base 17. The middle support 60 is provided with a bottom insertion positioning groove 61 and a top insertion positioning hole 62. Both the bottom insertion positioning groove 61 and the top insertion positioning hole 62 are matched with the track adjustment frame 20. The top insertion positioning hole 62 is provided with a screw hole, and a clamping bolt 63 matching the track adjustment frame 20 is provided in the screw hole, providing structural reinforcement for the track adjustment frame 20. The bottom end of the track adjustment frame 20 is inserted into the bottom insertion positioning groove 61 of the middle support 60 for track adjustment. The top of the frame 20 is fixed to the top insertion positioning hole 62 of the middle support 60 by the clamping bolt 63, and the track adjustment frame 20 passes through the insertion hole 58, thus forming a three-point support structure for the track adjustment frame 20, improving the structural stability of the track adjustment frame 20. The positioning plate 5 is provided with two positioning bolt through holes 10, the lower cover plate 4 is provided with two lower cover bolt through holes 12, and the upper cover plate 1 is provided with two upper cover bolt through holes 15. The positioning bolt through holes 10 are internally threaded with positioning clamping bolts 64 that match the positioning connecting frame 26, the upper cover bolt through holes 15 are internally threaded with upper clamping bolts 65 that match the upper connecting frame 24, and the lower cover bolt through holes 12 are internally threaded with lower clamping bolts 66 that match the lower connecting frame 25.The positioning plate 5, lower cover plate 4, and upper cover plate 1 are connected and installed relative to the positioning connecting frame 26, upper connecting frame 24, and lower connecting frame 25, respectively, to facilitate the disassembly, maintenance, and replacement of the positioning plate 5, lower cover plate 4, and upper cover plate 1.

[0039] The servo motor 50 in this embodiment is a conventional device known to those skilled in the art and available on the market. In this invention, we are simply using it without making any improvements to its structure or function. Its setting method, installation method, and electrical connection method can be easily explained by those skilled in the art by following the instructions for use. Therefore, we will not elaborate on them here.

[0040] In summary, the working principle of the welding fixture for copper-clad ceramic substrates (DBC) of power modules is as follows: First, the welding fixture is installed at the desired location. Then, the corresponding control circuit is connected according to the instruction manual for the servo motor 50. Powering on the servo motor 50 drives the rotation of the drive pulley 48. The rotation of the drive pulley 48 drives the transmission of the rear conveyor belt 19. The movement of the rear conveyor belt 19 drives the synchronous movement of the three progressive support plates 21. The synchronous movement of the three progressive support plates 21 drives the synchronous movement of the first-stage spring 43, the second-stage spring 44, and the third-stage spring 45. Under the separate transmission of the first-stage spring 43, the second-stage spring 44, and the third-stage spring 45... Three progressive support plates 21 drive three progressive clamping frames to move, which in turn drive three inner bushings 22 to move. The movement of the inner bushings 22 drives the movement of the three transmission columns 23. When the height of the three transmission columns 23 changes during movement, guided by the lower horizontal rail 27, the torsion rail 29, and the upper vertical rail 28, the transmission columns 23 can be rotated for adjustment. Specifically, when the transmission column 23 moves from the lower horizontal rail 27 to the upper vertical rail 28, the torsion rail 29 causes it to rotate 90 degrees clockwise. Conversely, when the transmission column 23 moves from the upper vertical rail 28 to the lower horizontal rail 27, the torsion rail 29 causes it to rotate 90 degrees counterclockwise. (See attached diagram.) Figure 1 As shown, at this time, all three transmission columns 23 are located within the lower horizontal track 27, and the upper cover plate 1, lower cover plate 4, positioning plate 5, and bottom support plate 7 are aligned vertically, as shown in the attached diagram. Figure 11As shown, all three transmission columns 23 are located within the upper longitudinal track 28. In this state, the upper cover plate 1, lower cover plate 4, and positioning plate 5 are all relatively separated from the bottom support plate 7. During the height change of the three inner bushings 22, the upper connecting frame 24, lower connecting frame 25, and positioning connecting frame 26 will be synchronously adjusted. The height changes of the upper connecting frame 24, lower connecting frame 25, and positioning connecting frame 26 will respectively adjust the height of the upper cover plate 1, lower cover plate 4, and positioning plate 5. When all three transmission columns 23 are in... As the upper cover plate 1, lower cover plate 4, and positioning plate 5 move downwards along the lower horizontal track 27, their heights also decrease synchronously. Since the upper cover plate 1, lower cover plate 4, and positioning plate 5 are arranged from top to bottom, during this synchronous height decrease, the positioning plate 5 will first contact the bottom support plate 7. Then, as the rear conveyor belt 19 continues to move and lower the heights of the upper cover plate 1 and lower cover plate 4, the positioning plate 5, supported by the bottom support plate 7, will not... The height will decrease further, and the corresponding third-stage spring 45 will be elastically stretched to ensure that the height of the upper cover plate 1 and the lower cover plate 4 continues to decrease. After the lower cover plate 4 contacts the top of the positioning plate 5, the positioning plate 5 provides support for the lower cover plate 4. After that, the rear conveyor belt 19 continues to run, which can only reduce the height of the upper cover plate 1, while the positioning plate 5 and the lower cover plate 4 will not reduce in height anymore. During this process, both the second-stage spring 44 and the third-stage spring 45 will be further elastically stretched. When the upper cover plate 1 and the lower cover plate 4... After the upper and lower contacts are formed, the complete mold closing of the fixture body is completed, which facilitates the smooth placement of the copper-clad ceramic substrate 6 and components such as chips, resistors and pin holders to be soldered into the fixture body. If it is necessary to increase the relative pressing force between the upper cover plate 1 and the lower cover plate 4 after the complete mold closing, the first-stage spring 43 can be further stretched by the continued movement of the rear conveyor belt 19 to improve the pressing effect between the upper cover plate 1 and the lower cover plate 4, and ensure the accuracy of the relative position of the copper-clad ceramic substrate 6 and its parts within the fixture body.

[0041] Furthermore, when the servo motor 50 controls the rear conveyor belt 19 to achieve reverse transmission, the upper cover plate 1 can first be separated from the lower cover plate 4, then the lower cover plate 4 can be separated from the positioning plate 5, and finally the positioning plate 5 can be separated from the bottom support plate 7. This facilitates the removal of the welded copper-clad ceramic substrate 6 from the fixture body, and then facilitates the insertion operation before welding the next copper-clad ceramic substrate 6. Furthermore, the external assembly frame 59 provides corresponding installation positions for the welding tool's supporting equipment. When manual welding is performed, a support frame for welding torch support or placement can be installed on the external assembly frame 59 to facilitate placement of the welding torch during breaks in manual welding operations. When the welding operation is automated, it also provides the necessary fixed installation station for welding robots. This welding fixture for copper-clad ceramic substrates of power modules can weld and position chips, resistors, and pin holders on the copper-clad ceramic substrate 6. By changing the upper cover plate 1, lower cover plate 4, and positioning plate 5, it can be used for welding applications with various layouts of copper-clad ceramic substrates 6, making it relatively flexible in terms of structure and processing. The fixture is easy to manufacture and meets the welding requirements of devices on copper-clad ceramic substrates 6. The fixture body mainly consists of six parts: an upper cover plate 1, a large pressure block 2, a small pressure block 3, a lower cover plate 4, a positioning plate 5, and a base plate 7. The base plate 7 has multiple DBC positioning slots 8, allowing simultaneous welding of multiple copper-clad ceramic substrates 6, improving welding efficiency. The positioning plate 5 mainly positions the chips, resistors, and pin headers on the copper layer of the copper-clad ceramic substrate 6. Due to its thinness and simple structure, and its tight fit with the four corners of the base plate 7 for auxiliary positioning, it achieves high positioning accuracy. The upright mounting of plate 5 allows for clear observation of whether the placed components are in place. The base plate 7 and positioning plate 5 adopt a four-corner embedded positioning structure, which not only ensures the matching accuracy of the two when the fixture is picked up and put down, but also effectively reduces the mechanical deformation of the copper-clad ceramic substrate 6 caused by welding thermal stress through structural constraints. The upper cover plate 1 and lower cover plate 4 adopt a matching form in which they are inserted one after the other relative to the positioning boss 11. The groove between the two is used to fill the large pressure block 2 and the small pressure block 3, so as to facilitate the pressing of the components on the surface of the copper-clad ceramic substrate 6, and ultimately achieve the purpose of efficient welding.

[0042] The advantages of the overall technology of this jig body are as follows:

[0043] This invention can simultaneously weld multiple copper-clad ceramic substrates 6 of a power module, greatly improving welding efficiency;

[0044] The present invention allows for the welding of copper-clad ceramic substrates 6 with different device layouts by replacing the upper cover plate 1, the lower cover plate 4, and the positioning plate 5.

[0045] This invention is simple to operate and easy to manufacture with low cost;

[0046] The bottom support plate 7 used in this invention is in close contact with the bottom of the reflow oven cavity, which greatly enhances the thermal conductivity and thus effectively improves the welding yield.

[0047] This invention can simultaneously solder passive devices such as chips, resistors, and pin headers on a copper-clad ceramic substrate 6, effectively improving soldering efficiency.

[0048] The upper cover plate 1, lower cover plate 4, positioning plate 5 and bottom support plate 7 in this invention are all made of aluminum alloy, which can reduce the contamination of passive components such as chips, resistors or pin holders caused by oxidation on the surface of the fixture during the welding process.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A welding fixture for copper-clad ceramic substrates (DBC) in power modules, comprising a fixture body and a copper-clad ceramic substrate (6), characterized in that, It also includes a support base (17). The fixture body includes an upper cover plate (1), a lower cover plate (4), a positioning plate (5), a bottom support plate (7), a large pressure block (2), and a small pressure block (3). The large pressure block (2) and the small pressure block (3) are both installed on the lower cover plate (4). The bottom support plate (7) has multiple DBC positioning grooves (8) and four bottom plate bolt through holes (9). The multiple DBC positioning grooves (8) are used for auxiliary positioning of the copper-clad ceramic substrate (6). The positioning plate (5) is provided with two positioning bosses (11). The lower cover plate (4) The upper cover plate (1) is provided with two lower cover positioning grooves (13) and multiple pressure block positioning holes (14). The upper cover plate (1) is provided with two upper cover positioning grooves (16). The two lower cover positioning grooves (13) are respectively matched with the two positioning bosses (11). The two upper cover positioning grooves (16) are respectively matched with the two positioning bosses (11). The upper cover plate (1), lower cover plate (4) and positioning plate (5) are installed on the bearing base (17) through an active drive assembly. The bottom support plate (7) is installed on the bearing base (17) through a vertical bracket (18). The active drive assembly includes a rear conveyor belt (19) and a track adjustment frame (20). The rear conveyor belt (19) is mounted on the support base (17). The track adjustment frame (20) is connected to the upright support (18). Three progressive support plates (21) are fixedly connected to the outside of the rear conveyor belt (19). Each of the three progressive support plates (21) is connected to a progressive clamping frame via an elastic component. Each of the three progressive clamping frames is rotatably connected to an inner bushing (22). Each of the three inner bushings (22) is fixedly connected to a transmission column (23). Each of the three transmission columns (23) is matched with the track adjustment frame (20). The upper connecting frame (24), the lower connecting frame (25) and the positioning connecting frame (26) are fixedly connected to the outside of the three inner bushings (22). The upper connecting frame (24), the lower connecting frame (25) and the positioning connecting frame (26) are fixedly connected to the upper cover plate (1), the lower cover plate (4) and the positioning plate (5) respectively. The track adjustment frame (20) is provided with a lower horizontal track (27) and an upper vertical track (28). The lower horizontal track (27) and the upper vertical track (28) are connected by a torsion track (29). The lower horizontal track (27), the upper vertical track (28) and the torsion track (29) are all matched with the transmission column (23).

2. The welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 1, characterized in that, The three progressive clamping frames include a primary slot frame (30), a secondary slot frame (31), and a tertiary slot frame (32). The primary slot frame (30), secondary slot frame (31), and tertiary slot frame (32) are arranged sequentially from top to bottom. The primary slot frame (30), secondary slot frame (31), and tertiary slot frame (32) are respectively fixedly connected to a primary pressure frame (33), a secondary pressure frame (34), and a tertiary pressure frame (35). The primary slot frame (30), secondary slot frame (31), tertiary slot frame (32), primary pressure frame (33), secondary pressure frame (34), and tertiary pressure frame (35) are all provided with semi-annular grooves (36) that match the inner liner (22).

3. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 2, characterized in that, A primary guide sleeve (37) is fixedly connected between the primary slot frame (30) and the primary pressure frame (33). A secondary guide sleeve (38) is fixedly connected between the secondary slot frame (31) and the secondary pressure frame (34). A tertiary guide sleeve (39) is fixedly connected between the tertiary slot frame (32) and the tertiary pressure frame (35). The primary guide sleeve (37), the secondary guide sleeve (38), and the tertiary guide sleeve (39) are slidably connected to a primary guide prism (40), a secondary guide prism (41), and a tertiary guide prism (42), respectively. The prism (42) is fixedly connected to the three progressive support plates (21) respectively. The three progressive support plates (21) are respectively fixedly connected to the first-level spring (43), the second-level spring (44) and the third-level spring (45). The first-level spring (43), the second-level spring (44) and the third-level spring (45) are respectively fitted outside the first-level guide prism (40), the second-level guide prism (41) and the third-level guide prism (42), and the first-level spring (43), the second-level spring (44) and the third-level spring (45) are respectively fixedly connected to the first-level guide sleeve (37), the second-level guide sleeve (38) and the third-level guide sleeve (39).

4. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 3, characterized in that, A fixed side frame (46) is fixedly connected to the bearing base (17), and an assembly side frame (47) is installed on the bearing base (17). A drive pulley (48) and a transmission pulley (49) are rotatably installed on the fixed side frame (46). The rear conveyor belt (19) is driven between the drive pulley (48) and the transmission pulley (49). A servo motor (50) is installed outside the fixed side frame (46). The output shaft of the servo motor (50) is drivenly connected to the drive pulley (48). Two rotating support holes (51) are provided on the assembly side frame (47). The two rotating support holes (51) are respectively matched with the drive pulley (48) and the transmission pulley (49).

5. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 4, characterized in that, The support base (17) is fixedly connected to a track frame (52), and the assembly side frame (47) is provided with a track sleeve (53). The track sleeve (53) matches the track frame (52). The track sleeve (53) has multiple threaded holes, and each of the multiple threaded holes is threaded with a positioning bolt (54) for pressing and positioning the track sleeve (53) relative to the track frame (52).

6. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 5, characterized in that, The top of the support frame (18) is provided with a support frame (55), and the support frame (55) is fixedly connected with a mounting slot plate (56) by a pressing bolt. All four bottom plate bolt through holes (9) are provided with internal hexagon bolts, and all four internal hexagon bolts are threaded to the mounting slot plate (56). An insertion bracket (57) is fixedly connected to the rear side of the support frame (55), and the insertion bracket (57) is provided with an insertion hole (58) for inserting the track adjustment frame (20). An external assembly frame (59) is fixedly connected to the right end of the support frame (55).

7. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 6, characterized in that, A middle support (60) is fixedly connected to the bearing base (17). The middle support (60) is provided with a bottom insertion positioning groove (61) and a top insertion positioning hole (62). The bottom insertion positioning groove (61) and the top insertion positioning hole (62) are matched with the track adjustment frame (20). The top insertion positioning hole (62) is provided with a screw hole. A clamping bolt (63) matching the track adjustment frame (20) is provided in the screw hole.

8. A welding fixture for copper-clad ceramic substrates (DBC) in power modules according to claim 7, characterized in that, The positioning plate (5) is provided with two positioning bolt through holes (10), the lower cover plate (4) is provided with two lower cover bolt through holes (12), the upper cover plate (1) is provided with two upper cover bolt through holes (15), the positioning bolt through holes (10) are internally threaded with positioning pressing bolts (64) that match the positioning connecting frame (26), the upper cover bolt through holes (15) are internally threaded with upper pressing bolts (65) that match the upper connecting frame (24), and the lower cover bolt through holes (12) are internally threaded with lower pressing bolts (66) that match the lower connecting frame (25).

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