A test fixture for SiC MOSFET discrete devices

Abstract

The present invention discloses a test fixture for SiC MOSFET discrete devices, including a fixture base, and a first box body and a second box body located on both sides of the fixture base, wherein a through slot is provided on both side walls of the first box body, and a first guide rail is bolted to the top and bottom of the through slot, and a movable block is inserted into the through slot, and a conductive test strip is slidably connected to the movable block, and an elastic sheet is connected to one end of the conductive test strip, and two groups of symmetrically distributed fixed plates and two symmetrically distributed movable plates are arranged inside the second box body, and a driving mechanism for driving the two movable plates to move relatively close to and relatively away from each other. Two movable blocks are arranged on both sides of the first box body of the present invention, and a plurality of conductive test strips are movably arranged on the movable blocks. According to the number of pins of the discrete device, the corresponding number of conductive test strips are moved to contact the pins, so that the device can be applied to the testing operations of discrete devices of different models, and has strong applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of testing tools, and in particular to a testing tool for SiC MOSFET discrete devices. Background Art

[0002] With the widespread application of silicon carbide (SiC) materials in high voltage, high temperature, high frequency and other fields, SiC MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) discrete devices have gradually become the core components of modern power electronic systems due to their excellent electrical properties, such as high breakdown voltage, low on-resistance and good thermal stability. Therefore, the testing of SiC MOSFET discrete devices is crucial to ensure their performance and reliability.

[0003] In the prior art, most of the test fixtures for discrete devices rely on traditional test platforms, and usually only consider a single model of discrete devices during design, while ignoring the adaptability of multiple models, multiple pin distributions and different packaging forms. For example, patent CN205049603U discloses a test fixture for sorting discrete devices. In its design, the test is completed by placing the workpiece to be tested on the table and contacting the test piece with the pins. Although this design can improve the test efficiency to a certain extent, its limitations are also very obvious: First, the differences in the pin layout, number and type of discrete devices require that the test piece be readjusted or replaced each time the test is performed, which not only makes the adaptability of the equipment poor, but also increases the complexity of the operation, resulting in reduced test efficiency. Secondly, the test piece and pins are exposed to the outside, and the operator can easily come into contact with the live parts, which poses a great safety hazard.

[0004] In addition, existing test fixtures usually use a fixed hard contact method and do not have a sufficiently flexible adjustment mechanism. Since the number and layout of pins of different models of SiC MOSFET vary, traditional hard contact designs often cannot guarantee accurate contact of all pins. As a result, poor contact may occur during the test process, affecting the accuracy and stability of the test results. Moreover, most existing test fixtures rely on manual adjustment of the position of the test contacts and lack automated adjustment functions, which not only increases the complexity of manual operations but also reduces production efficiency.

[0005] On the other hand, during the test, the contact points between the pins of discrete devices and the test piece are often exposed, which can easily lead to safety problems such as electric shock due to improper operation. Especially in high temperature and high pressure working environments, traditional test tools lack the necessary protection design, which can easily cause equipment failure or personal injury.

[0006] In summary, although the existing test fixtures have solved the basic needs of discrete device testing to a certain extent, they still have great deficiencies in adaptability, accuracy, safety and automation level. Therefore, the market urgently needs a new test fixture that can effectively improve test accuracy, enhance equipment adaptability, reduce manual intervention, and improve safety to meet the needs of modern efficient and reliable SiC MOSFET discrete device testing. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0008] Therefore, an object of the present invention is to provide a test fixture for SiC MOSFET discrete devices, comprising a fixture base, and a first box body and a second box body located on both sides of the fixture base.

[0009] A through slot is provided on both side walls of the first box body, a first guide rail is bolted to the top and bottom of the through slot, a movable block is inserted into the through slot, a first slider matched with the first guide rail is provided on the top and bottom surfaces of the movable block, a conductive test strip is slidably connected to the movable block, and an elastic sheet is connected to one end of the conductive test strip.

[0010] The second box body is sleeved with a fixing frame at one end away from the first box body, and a rotating shaft connected to its bearings passes through both sides of the fixing frame. One end of the rotating shaft is fixedly connected to the outer wall of the second box body, and the fixing frame is slidably connected to the tooling base.

[0011] The second box body is provided with two groups of symmetrically distributed fixed plates, two symmetrically distributed movable plates, and a driving mechanism for driving the two movable plates to move relatively closer or farther away from each other.

[0012] Each group of the fixing plates is provided with two, and the two fixing plates are arranged one in front and one behind.

[0013] As the preferred technical solution:

[0014] In the test fixture for SiC MOSFET discrete devices as described above, the opposite ends of the first box body and the second box body are both open, the first box body and the second box body are both made of transparent acrylic material, and the first box body is fixedly connected to the fixture base.

[0015] Through the above technical solution, the interior of the second box body is used to place discrete devices. When the first box body and the second box body are close to each other, the pins on the discrete devices in the second box body can be inserted into the first box body for testing. In this way, during the test process, it is possible to avoid accidentally touching the pins on the discrete devices and the conductive test strips, thereby improving the safety of the test.

[0016] As described above, a test fixture for SiC MOSFET discrete devices has a set of second guide rails bolted to the surface of the fixture base, a set of grooves are opened on the bottom surface of the second box body, and support blocks are embedded in the grooves. The support blocks and the bottom ends of the fixing frame are both provided with second sliders adapted to the second guide rails.

[0017] Through the above technical solution, one end of the second box body is a movable structure through the rotating shaft, and the other end of the second box body can be supported by the supporting block, so that the second box body can be in a horizontal state as a whole. After the second box body is close to the first box body, the pins on the discrete device can be accurately fitted with the elastic sheet.

[0018] In the test fixture for SiC MOSFET discrete devices as described above, two movable blocks are arranged in the through slot, the lengths of the conductive test strips on the two movable blocks are different, at least two conductive test strips are arranged on the movable block, and the conductive test strips on the movable block are all on the same horizontal plane.

[0019] Through the above technical solution, since the fixed plates of each group are arranged one in front of the other, the positions of the discrete devices on the two fixed plates are also one in front of the other, and the conductive test strips on the two movable blocks are set to a suitable length, thereby ensuring that the conductive test strips on the two movable blocks can contact the pins on the two discrete devices, and the structure is reasonable.

[0020] As described above, a test fixture for SiC MOSFET discrete devices, wherein a cavity for placing a conductive tube is provided inside the movable block, the number of conductive test strips and conductive tubes on the movable block is the same, both ends of the conductive tube are open, one end of the conductive test strip passes through the movable block and is inserted into the conductive tube, and a push strip is inserted into the other end of the conductive tube, and one end of the push strip passes through the wall of the movable block.

[0021] The outer walls of the push bar and the conductive test bar are both in contact with the inner wall of the conductive tube, the push bar and the movable block are both made of insulating materials, and the push bar is fixedly bonded to one end of the conductive test bar.

[0022] Through the above technical solution, the conductive tube is fixedly bonded in the cavity, and the conductive tube is in the shape of a long strip as a whole. The conductive test strip and the push strip can move linearly in the conductive tube, so that the position of the conductive test strip can be adjusted by moving the push strip. The push strip and the movable block are made of bakelite or other materials, which have good insulation properties, so that electric shock will not occur when the push strip is touched, thereby improving overall safety.

[0023] As described above, in a test fixture for SiC MOSFET discrete devices, the elastic sheet has a horizontal portion and a bent portion, the horizontal portion of the elastic sheet is located above a conductive test strip, a conductive graphite layer is attached to the surface of the horizontal portion of the elastic sheet, the bent portion of the elastic sheet is welded to one end of the conductive test strip, and one side of the conductive graphite layer is an inclined surface.

[0024] Through the above technical solution, the elastic sheet can be selected with different thicknesses according to needs, for example, the thickness is 0.1mm, so that the elastic sheet can undergo a certain bending deformation through the bending portion. The elastic potential energy generated by the deformation of the elastic sheet can fit tightly with the pins on the discrete device to ensure the test effect.

[0025] In the test fixture for SiC MOSFET discrete devices as described above, a vertical hole groove is opened on the bottom surface of the movable block, the top of the hole groove is connected to the cavity, a conductive metal sheet is arranged in the hole groove, and the top of the conductive metal sheet is welded to the conductive tube.

[0026] Through the above technical solution, the conductive metal sheet is connected to the test machine through a wire, and the conductive test strip, elastic sheet, conductive tube, and conductive metal sheet can be combined into a path, and all four are made of copper, which has good conductivity and ensures the accuracy of the test.

[0027] In the test fixture for SiC MOSFET discrete devices as described above, the driving mechanism includes a set of guide rods and a screw rod, both ends of the guide rods are fixedly bonded to the inner wall of the second box body, and both ends of the screw rod penetrate the wall of the second box body and are movably connected to the second box body bearing.

[0028] The screw rod is provided with two sections of threads in forward and reverse directions, and two protrusions are sleeved on the screw rod. The two protrusions are respectively screwed with the two sections of threads, and the guide rod passes through the protrusions and is slidably connected with the protrusions.

[0029] The movable plate comprises a bottom plate, and a first side plate and a second side plate located at two sides of the bottom plate. The bottom plate, the first side plate and the second side plate are an integrated structure, and the bottom plate and the protrusion are an integrated structure.

[0030] The first side plate and the second side plate are perpendicular to the bottom plate, and the length of the first side plate is shorter than the length of the second side plate.

[0031] Through the above technical solution, a handwheel is provided at one end of the screw rod, and the screw rod can be manually rotated by the handwheel. Since the protrusion can move linearly on a set of guide rods, when the screw rod rotates forward or reversely, the two sections of thread on the screw rod can drive the two protrusions on it to move closer to or away from each other, and then the two protrusions can drive the two movable plates to move closer to or away from each other synchronously.

[0032] In the test fixture for SiC MOSFET discrete devices as described above, the fixing plate is an "L"-shaped structure, the fixing plate is fixedly bonded to the inner wall of the second box body, the vertical end of the fixing plate is parallel to the first side plate and the second side plate, and the horizontal end of the fixing plate is parallel to the bottom plate.

[0033] Through the above technical solution, the packaging shell of the discrete device is mostly rectangular, so that the two side surfaces of the discrete device can be fitted with the vertical end and the horizontal end of the fixed plate, and when the movable plate moves, it can fit with the other side surface of the discrete device through the first side plate or the second side plate, thereby realizing the clamping and fixing operation of the discrete device.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] (1) High adaptability, supporting accurate testing of multiple models of discrete devices. The test fixture of the present invention can automatically adjust the position of the test strip according to the number and position of the pins of different models of SiC MOSFET discrete devices by designing an adjustable conductive test strip in the first box body and the second box body, thereby realizing accurate testing of various models and specifications of discrete devices. The conductive test strip slidingly set on the movable block can be flexibly adjusted according to the number of pins of the discrete device to ensure that each pin can perfectly contact the conductive test strip. This design breaks through the restrictions of the existing test fixture on the number and position of pins, greatly improves adaptability and versatility, and can complete the testing of different models of discrete devices at one time, avoiding the tedious process of re-adjusting or replacing the test equipment due to model mismatch in traditional testing. Through the flexible adjustment mechanism and modular conductive test strip configuration, the compatibility and versatility of the equipment are improved, and the time cost of equipment replacement and configuration in the production line is reduced.

[0036] (2) Enhanced safety design ensures safe operation. A first box body and a second box body are arranged on the tooling base. The second box body can slide relative to the first box body. The first box body is used to place a conductive test strip, and the second box body is used to place and fix the semiconductor discrete device. The second box body can extend the pins of the semiconductor discrete device into the first box body by moving. In this way, the part where the pins of the discrete device contact the conductive test strip is inside the first box body, which can avoid accidental contact and improve the overall safety.

[0037] (3) Precision clamping and automatic adjustment to improve test accuracy and stability. The test fixture of the present invention adopts an innovative clamping mechanism, using a symmetrically distributed fixed plate and movable plate structure. The relative position of the movable plate is adjusted by a driving mechanism to ensure that the discrete device always maintains a stable clamping state during the test process, avoiding test errors caused by vibration or displacement. Especially during the installation and testing of discrete devices, the cooperation of the fixed plate and the movable plate ensures the precise alignment of the discrete device, so that the contact between the conductive test strip and the pin is always maintained in an ideal state. Through this clamping design, the error in the test process is greatly reduced, ensuring the accuracy and consistency of the test results.

[0038] (4) Automated design significantly improves test efficiency. The conductive test strip of the present invention uses the design of movable blocks and elastic sheets so that the contact points of the conductive test strip can be automatically adjusted according to the number of discrete device pins during the test process to meet the test requirements of different types of discrete devices. The flexible adjustment of the number and position of the conductive test strips reduces the complexity of manual operation and improves test efficiency. In traditional test equipment, each time a different type of discrete device is tested, it is often necessary to manually adjust the test strip or reinstall the test module. The present invention uses an automatic adjustment mechanism to make the test process faster and more convenient, and there is no need for repeated operations. In addition, the design of the elastic sheet ensures close contact between the conductive test strip and the pins, reducing the problem of inaccurate testing due to poor contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 A top view of the present invention;

[0041] Figure 2 is a side view of the present invention;

[0042] Figure 3 It is an internal top view of the present invention;

[0043] Figure 4 It is an internal top view of the present invention under the test state;

[0044] Figure 5 It is a front longitudinal sectional view of the tooling base and the first box body of the present invention;

[0045] Figure 6 For the present invention Figure 5 Enlarged view of point A in the middle;

[0046] Figure 7 It is a top cross-sectional view of the movable block and the conductive cylinder of the present invention;

[0047] Figure 8 A three-dimensional diagram of a conductive test strip and a conductive cartridge of the present invention;

[0048] Fig. 9 It is a three-dimensional diagram of the interior of the second box body of the present invention;

[0049] Fig.10 It is a three-dimensional diagram of the movable plate of the present invention.

[0050] In the figure: 1. tooling base; 2. first box body; 3. second box body; 4. fixed frame; 5. rotating shaft; 6. first guide rail; 7. support block; 8. through slot; 9. second guide rail; 10. movable block; 11. conductive test strip; 12. elastic sheet; 13. conductive graphite layer; 14. conductive cylinder; 15. push strip; 16. hole slot; 17. conductive metal sheet; 18. fixed plate; 19. movable plate; 191. bottom plate; 192. first side plate; 193. second side plate; 20. bump; 21. screw rod; 22. guide rod. DETAILED DESCRIPTION

[0051] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0052] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0053] like Figure 1-4 As shown, an embodiment of the present invention discloses a test fixture for SiC MOSFET discrete devices, including a fixture base 1, and a first box body 2 and a second box body 3 located on both sides of the fixture base 1, the opposite ends of the first box body 2 and the second box body 3 are both open, the first box body 2 and the second box body 3 are both made of transparent acrylic material, and the first box body 2 is fixedly connected to the fixture base 1.

[0054] A through slot 8 is provided on both side walls of the first box body 2, and a first guide rail 6 is bolted to the top and bottom of the through slot 8. A movable block 10 is inserted into the through slot 8, and a first slider matched with the first guide rail 6 is provided on the top and bottom surfaces of the movable block 10. A conductive test strip 11 is slidably connected to the movable block 10, and an elastic sheet 12 is connected to one end of the conductive test strip 11. Two movable blocks 10 are provided in the through slot 8, and the lengths of the conductive test strips 11 on the two movable blocks 10 are different. There are at least two conductive test strips 11 on the movable block 10, and the conductive test strips 11 on the movable block 10 are all on the same horizontal plane.

[0055] A fixing frame 4 is sleeved on one end of the second box body 3 away from the first box body 2. A rotating shaft 5 connected to its bearings passes through both sides of the fixing frame 4. One end of the rotating shaft 5 is fixedly connected to the outer wall of the second box body 3. The fixing frame 4 is slidably connected to the tooling base 1.

[0056] Two groups of symmetrically distributed fixed plates 18 and two symmetrically distributed movable plates 19 are arranged inside the second box body 3, as well as a driving mechanism for driving the two movable plates 19 to move relatively closer or farther away from each other.

[0057] Each group of fixing plates 18 is provided with two fixing plates 18, and the two fixing plates 18 are arranged one in front and one behind.

[0058] Before testing, the discrete device needs to be fixed first. By rotating the shaft 5, the second box body 3 can be flipped upward 90° on the fixing frame 4, so that the open end of the second box body 3 faces upward. At this time, the shell part of the discrete device can be inserted into the second box body 3, and the pin part is exposed. The shell of the discrete device can be fitted with the fixing plate 18, and the two movable plates 19 are driven to move by the driving mechanism. The movable plate 19 cooperates with the fixed plate 18 to clamp the discrete device to avoid displacement of the discrete device during the test, which affects the accuracy of the test.

[0059] A specified number of conductive test strips 11 are moved according to the number of discrete device pins. For example, if there are two discrete device pins to be tested, two conductive test strips 11 are slid one after the other on the movable block 10 to a suitable position.

[0060] After the discrete device is fixed, the second box body 3 is rotated to a horizontal state again and pushed to slide on the tooling base 1 , so that the second box body 3 and the first box body 2 can be brought closer to each other until the pins of the discrete device are inserted into the first box body 2 .

[0061] Since the first slider can move linearly along the first guide rail 6, the movable block 10 can move along the length direction of the through slot 8. During the movement, the movable block 10 can drive the conductive test strip 11 to move until the elastic sheet 12 on the conductive test strip 11 contacts the pin of the discrete device, and then the electrical performance test of the discrete device can be performed.

[0062] The two discrete devices on each group of fixed plates 18 are arranged side by side, and the two discrete devices are distributed one after the other. The conductive test strip 11 on one of the movable blocks 10 in the through slot 8 is longer, and the conductive test strip 11 on the other movable block 10 is shorter, and the two movable blocks 10 are distributed one after the other. In this way, under the premise of ensuring that the conductive test strip 11 on the movable block 10 is in contact with the pins of the discrete device, it is avoided that the pins of two discrete devices are in contact with the conductive test strip 11 on one movable block 10, thereby ensuring the test effect.

[0063] The first box body 2 and the second box body 3 are both made of transparent materials, which is convenient for observing the movement position of the conductive test strip 11 inside and the placement position of the discrete components. At the same time, acrylic has good insulation properties, ensuring safety during the test process.

[0064] like Figure 1 and Figure 2 As shown, a group of second guide rails 9 are bolted to the surface of the tooling base 1, a group of grooves are opened on the bottom surface of the second box body 3, and a support block 7 is embedded in the groove. The bottom ends of the support block 7 and the fixing frame 4 are both provided with a second slider adapted to the second guide rails 9.

[0065] The second box body 3 can be freely flipped by the rotating shaft 5 for the purpose of placing and removing discrete devices. When the second box body 3 is close to the first box body 2, the second box body 3 needs to be kept horizontal to ensure that the pins of the discrete devices can accurately contact the elastic sheet 12.

[0066] A support block 7 is further provided. When the second box body 3 is flipped to a horizontal position, the groove at the bottom of the second box body 3 can be engaged with the top of the support block 7. In this way, the support block 7 can cooperate with the fixing frame 4 to support the second box body 3 horizontally, and cooperate with the second slider so that the second box body 3 can maintain a horizontal state and slide along the second guide rail 9.

[0067] like Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown, a cavity for placing a conductive tube 14 is provided inside the movable block 10. The number of conductive test strips 11 and conductive tubes 14 on the movable block 10 is the same. Both ends of the conductive tubes 14 are open. One end of the conductive test strip 11 passes through the movable block 10 and is inserted into the conductive tube 14. A push strip 15 is inserted into the other end of the conductive tube 14. One end of the push strip 15 passes through the wall of the movable block 10.

[0068] The outer walls of the push bar 15 and the conductive test bar 11 are both in contact with the inner wall of the conductive tube 14 . The push bar 15 and the movable block 10 are both made of insulating materials. The push bar 15 is fixedly bonded to one end of the conductive test bar 11 .

[0069] A vertical hole 16 is formed on the bottom surface of the movable block 10 . The top of the hole 16 is connected to the cavity. A conductive metal sheet 17 is disposed in the hole 16 . The top of the conductive metal sheet 17 is welded to the conductive tube 14 .

[0070] Since the conductive metal sheet 17 is connected to the test machine through a wire, the conductive metal sheet 17, the conductive tube 14, the conductive test strip 11 and the elastic sheet 12 form a passage, so there is a risk of electric shock when the conductive test strip 11 is moved. Therefore, a push bar 15 is provided. The push bar 15 is made of insulating material. By moving the push bar 15 linearly in the conductive tube 14, the conductive test strip 11 can be moved to adjust the position of the elastic sheet 12. According to the number of pins of the discrete device, a suitable number of elastic sheets 12 can be pushed out.

[0071] The connection portion between the wire and the conductive metal sheet 17 is located inside the hole 16, thus avoiding being touched, further improving the overall safety.

[0072] like Figure 8 As shown, the elastic sheet 12 has a horizontal portion and a bent portion. The horizontal portion of the elastic sheet 12 is located above the conductive test strip 11. A conductive graphite layer 13 is attached to the surface of the horizontal portion of the elastic sheet 12. The bent portion of the elastic sheet 12 is welded to one end of the conductive test strip 11, and one side of the conductive graphite layer 13 is an inclined surface.

[0073] The inclined surface of the conductive graphite layer 13 is set so that when the movable block 10 drives the elastic sheet 12 to contact the pin through the conductive test strip 11, the horizontal part of the elastic sheet 12 will indirectly contact the pin through the conductive graphite layer 13. When the inclined surface of the conductive graphite layer 13 contacts the pin, the pin will apply a downward extrusion force to the conductive graphite layer 13. After the elastic sheet 12 is subjected to pressure, it can bend and deform on the conductive metal sheet 17 through the bending portion. The elastic potential energy generated by the deformation of the elastic sheet 12 causes the conductive graphite layer 13 to fit closely with the pin, thereby avoiding separation of the conductive graphite layer 13 and the pin, thereby improving the accuracy of the test.

[0074] like Figure 3 , Fig. 9 and Fig.10 As shown, the driving mechanism includes a group of guide rods 22 and a screw rod 21, both ends of the guide rod 22 are fixedly bonded to the inner wall of the second box body 3, both ends of the screw rod 21 penetrate the wall of the second box body 3 and are movably connected to the bearings of the second box body 3, two sections of threads in positive and negative directions are provided on the screw rod 21, two protrusions 20 are sleeved on the screw rod 21, the two protrusions 20 are respectively screwed with the threads at both ends, and the guide rod 22 penetrates the protrusion 20 and is slidably connected to the protrusion 20.

[0075] The movable plate 19 includes a bottom plate 191 and a first side plate 192 and a second side plate 193 located at both sides of the bottom plate 191 . The bottom plate 191 , the first side plate 192 and the second side plate 193 are an integrated structure. The bottom plate 191 and the protrusion 20 are an integrated structure.

[0076] The first side plate 192 and the second side plate 193 are perpendicular to the bottom plate 191 , and the length of the first side plate 192 is smaller than the length of the second side plate 193 .

[0077] The fixing plate 18 is an “L”-shaped structure. The fixing plate 18 is fixedly bonded to the inner wall of the second box body 3 . The vertical end of the fixing plate 18 is parallel to the first side plate 192 and the second side plate 193 . The horizontal end of the fixing plate 18 is parallel to the bottom plate 191 .

[0078] The shape design of the fixing plate 18 can match the shape of the package shell of the discrete device, so that the shell of the discrete device can fit tightly with the fixing plate 18, so that the discrete devices on the fixing plate 18 in each group are distributed one after the other.

[0079] When the bottom plate 191 moves driven by the protrusion 20, it can synchronously drive the first side plate 192 and the second side plate 193 to move. The first side plate 192 and the second side plate 193 are one short and one long, which can correspond to two discrete components one in front and one behind. Then, the first side plate 192 and the second side plate 193 can contact the sides of the two discrete components, and cooperate with the fixing plate 18 to clamp and fix the discrete components to avoid the movement of the discrete components during the test.

[0080] In the description of this specification, "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0082] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test fixture for SiC MOSFET discrete devices, comprising a fixture base (1), and a first box body (2) and a second box body (3) located on both sides of the fixture base (1), characterized in that: A through slot (8) is formed on both side walls of the first box body (2); a first guide rail (6) is bolted to the top and bottom of the through slot (8); a movable block (10) is inserted into the through slot (8); a first slider matched to the first guide rail (6) is provided on the top and bottom surfaces of the movable block (10); a conductive test strip (11) is slidably connected to the movable block (10); one end of the conductive test strip (11) is connected to an elastic sheet (12); The second box body (3) is sleeved with a fixing frame (4) at one end away from the first box body (2), and a rotating shaft (5) connected to the bearing thereof passes through both sides of the fixing frame (4), one end of the rotating shaft (5) is fixedly connected to the outer wall of the second box body (3), and the fixing frame (4) is slidably connected to the tooling base (1). The second box body (3) is provided with two groups of symmetrically distributed fixed plates (18), two symmetrically distributed movable plates (19), and a driving mechanism for driving the two movable plates (19) to move relatively closer together or relatively farther apart. Each group of the fixed plates (18) is provided with two, and the two fixed plates (18) are arranged one in front of the other.

2. A test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: The opposite ends of the first box body (2) and the second box body (3) are both open, the first box body (2) and the second box body (3) are both made of transparent acrylic material, and the first box body (2) is fixedly connected to the tooling base (1).

3. A test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: A set of second guide rails (9) are fixed to the surface of the tooling base (1) by bolts, a set of grooves are provided on the bottom surface of the second box body (3), a support block (7) is embedded in the groove, and a second slide block adapted to the second guide rails (9) is provided at the bottom end of the support block (7) and the fixing frame (4).

4. A test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: Two movable blocks (10) are arranged in each through slot (8); the conductive test strips (11) on the two movable blocks (10) have different lengths; at least two conductive test strips (11) are arranged on each movable block (10); and the conductive test strips (11) on the movable blocks (10) are all located on the same horizontal plane.

5. The test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: The movable block (10) has a cavity for placing the conductive tube (14) inside. The number of conductive test strips (11) and conductive tubes (14) on the movable block (10) is the same. Both ends of the conductive tube (14) are open. One end of the conductive test strip (11) passes through the movable block (10) and is inserted into the conductive tube (14). The other end of the conductive tube (14) is inserted with a push strip (15). One end of the push strip (15) passes through the wall of the movable block (10). The outer walls of the push bar (15) and the conductive test bar (11) are both in contact with the inner wall of the conductive tube (14); the push bar (15) and the movable block (10) are both made of insulating material; and the push bar (15) is fixedly bonded to one end of the conductive test bar (11).

6. A test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: The elastic sheet (12) comprises a horizontal portion and a bent portion, the horizontal portion of the elastic sheet (12) being located above the conductive test strip (11), a conductive graphite layer (13) being attached to the surface of the horizontal portion of the elastic sheet (12), the bent portion of the elastic sheet (12) being welded to one end of the conductive test strip (11), and one side of the conductive graphite layer (13) being an inclined surface.

7. A test fixture for SiC MOSFET discrete devices according to claim 5, characterized in that: A vertical hole groove (16) is provided on the bottom surface of the movable block (10), the top of the hole groove (16) is connected to the cavity, a conductive metal sheet (17) is arranged in the hole groove (16), and the top of the conductive metal sheet (17) is welded to the conductive tube (14).

8. The test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: The driving mechanism comprises a group of guide rods (22) and a screw rod (21), the two ends of the guide rods (22) being fixedly bonded to the inner wall of the second box body (3), and the two ends of the screw rod (21) passing through the wall of the second box body (3) and being movably connected to the bearing of the second box body (3). The screw rod (21) is provided with two sections of threads in forward and reverse directions. Two protrusions (20) are sleeved on the screw rod (21). The two protrusions (20) are respectively screwed with the two sections of threads. The guide rod (22) passes through the protrusions (20) and is slidably connected with the protrusions (20).

9. The test fixture for SiC MOSFET discrete devices according to claim 1, characterized in that: The movable plate (19) comprises a bottom plate (191), and a first side plate (192) and a second side plate (193) located on both sides of the bottom plate (191); the bottom plate (191), the first side plate (192) and the second side plate (193) are an integrated structure; and the bottom plate (191) and the protrusion (20) are an integrated structure; The first side plate (192) and the second side plate (193) are perpendicular to the bottom plate (191), and the length of the first side plate (192) is shorter than the length of the second side plate (193).

10. A test fixture for SiC MOSFET discrete devices according to claim 9, characterized in that: The fixing plate (18) is of an "L"-shaped structure. The fixing plate (18) is fixedly bonded to the inner wall of the second box body (3). The vertical end of the fixing plate (18) is parallel to the first side plate (192) and the second side plate (193). The horizontal end of the fixing plate (18) is parallel to the bottom plate (191).

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