Test fixture with PIN offset control

Abstract

This utility model discloses a test fixture with PIN offset control, including a fixture support, a fixture probe plate, a PIN offset control plate disposed on the fixture probe plate, and a movable pull-out alignment base disposed on the fixture support for placing a power module. The pull-out alignment base is located below the PIN offset control plate, and the PIN offset control plate has holes corresponding to the positions of the PIN pins on the power module. This utility model's test fixture with PIN offset control, by incorporating the PIN offset control plate, integrates PIN offset detection functionality, thereby improving the accuracy of test results and the efficiency of testing.

Description

Technical Field

[0001] This utility model belongs to the field of testing technology. Specifically, this utility model relates to a test fixture with PIN pin offset control. Background Technology

[0002] IGBTs (Insulated Gate Bipolar Transistors) are the "CPU" of modern power electronics. Their primary function is in high-voltage, high-current, high-power applications. This necessitates IGBTs possessing strong impact resistance (new energy vehicles, industrial frequency converters), high-voltage withstand capability (wind power), and excellent heat dissipation. Large-size designs represent the optimal engineering solution under the constraints of power, heat dissipation, insulation, and reliability. During installation, due to the high integration of the electrical control system and limited installation space, large-size IGBTs typically require a PCB board to connect to the product's pins to provide voltage for operation. The PCB driver board integrates the IGBT gate driver IC, IGBT gate switch resistors, protection circuits, and other components. These components are soldered to the product's pins through holes in the PCB board. When assembling the PCB at the customer's site, the assembly board is fitted onto the product using the housing's limiting posts, and then screwed into the product's screw holes for fixation. During installation, the product's pins must remain straight and their relative positions to the housing screw holes and limiting posts must not deviate.

[0003] Existing methods for detecting PIN position misalignment in products include AOI (Automatic Optical Inspection Camera) inspection, manual PCB driver board insertion inspection, and 2D full-size measurement. However, these methods are costly and require significant equipment and personnel. Meanwhile, 100% of products leaving the production line require static parameter testing. Static testing not only screens out defects in the product packaging process but also provides customers with the product's electrical parameters. Currently, the production line uses low-cost manual static testing fixtures. The currently used manual static testing fixtures include... Figure 12 and Figure 13 As shown, during use, the operator needs to insert the product into the alignment base, then press down the fixture handle to make the connecting probes on the fixture probe plate contact the product's PIN pins, and then start testing the product's static parameters through the testing equipment. The existing fixture has the following disadvantages:

[0004] 1. There is no product pin offset control capability. When encountering products with offset or bent pins, the operator can only visually inspect them before testing. It is impossible to prevent products with offset pins from entering the fixture for testing, or to check the cause after the test fails to determine whether the test failure is due to pin offset or lack of contact.

[0005] 2. The test fixture alignment base is a fixed base. When the product is placed on the test fixture base, it is easy to bump into the connecting probe, causing the product PIN pin to bend. After the product PIN pin is bent, the connecting probe will not be able to contact the product PIN pin, resulting in test failure.

[0006] 3. The test fixture probe plate and the product body lack secondary positioning pins. When the probe plate is pressed down, the connecting probe and the product PIN may not align. When they do not align, pressing down the connecting probe will cause the product PIN to be bent and deformed, resulting in abnormal PIN conditions in the testing process.

[0007] Chinese Patent Application No. 202011540283.0 discloses a missing pin test fixture for a power module, including a mechanical support and a test fixture body disposed within the mechanical support. The test fixture body mainly includes a probe contact portion and a probe detection portion disposed vertically. The probe contact portion includes a first fixing plate and a plurality of contact probes vertically disposed on the first fixing plate, and a first probe circuit board is disposed on the probe contact portion. The probe detection portion includes a second fixing plate and a plurality of detection probes vertically disposed on the second fixing plate, and a second probe circuit board is disposed on the probe detection portion. The second probe circuit board is provided with a power supply and an indicator light. The technical solution disclosed in this patent document also fails to solve the above-mentioned defects.

[0008] This invention provides a test fixture with PIN offset control, specifically addressing how to improve the accuracy of test results and the efficiency of testing operations. Utility Model Content

[0009] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention provides a test fixture with PIN pin offset control, with the purpose of improving the accuracy of test results and the efficiency of testing work.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a test fixture with PIN offset control, including a fixture bracket, a fixture probe plate, a PIN pin control plate disposed on the fixture probe plate, and a movable pull-out alignment base disposed on the fixture bracket for placing a power module. The pull-out alignment base is located below the PIN pin control plate, and the PIN pin control plate is provided with holes corresponding to the positions of the PIN pins on the power module.

[0011] The fixture probe plate is provided with a positioning pin, which passes through the PIN pin control plate and is configured to be inserted into the screw hole on the power module.

[0012] Multiple positioning pins are provided.

[0013] There are four positioning pins, which are arranged in a rectangular pattern.

[0014] The positioning pin is made of stainless steel.

[0015] The fixture support is provided with base guide strips for guiding the pull-out alignment base, and the pull-out alignment base is located between two base guide strips.

[0016] This utility model relates to a test fixture with PIN offset control. By setting up a PIN offset control board, it integrates PIN offset detection function, which can improve the accuracy of test results and the efficiency of test work. Attached Figure Description

[0017] This manual includes the following figures, which illustrate the following:

[0018] Figure 1 This is a schematic diagram of the structure of the test fixture with PIN pin offset control according to this utility model;

[0019] Figure 2 This is a front view of the PIN pin control board.

[0020] Figure 3 This is a diagram of the reverse side of the PIN pin control board;

[0021] Figure 4 This is an assembly diagram of the fixture probe board and the PIN pin control board;

[0022] Figure 5 This is a structural diagram of a pull-out alignment base device;

[0023] Figure 6 This is the assembly diagram of the PIN pin control board;

[0024] Figure 7 This is a schematic diagram of the product assembly with the PIN pin control board;

[0025] Figure 8 This is the assembly diagram of the probe plate positioning pins;

[0026] Figure 9 This is an assembly diagram of a pull-out alignment base;

[0027] Figure 10 This is an assembly diagram of the pull-out base and the limiting groove;

[0028] Figure 11 This is a structural diagram of a pull-out alignment base;

[0029] Figure 12 This is a schematic diagram of the structure of an existing test fixture;

[0030] Figure 13 This is a contact diagram of the static fixture probe plate and the product;

[0031] Figure 14 It is a product structure diagram;

[0032] Figure 15 This is a product assembly diagram;

[0033] The markings in the diagram are as follows: 1. Fixture handle; 2. Downward guide post; 3. Probe plate bracket; 4. Fixture probe plate; 5. Positioning pin; 6. Connecting probe; 7. PIN pin control board; 8. Base guide strip; 9. Pull-out alignment base; 10. Fixture bracket; 11. Product; 12. Alignment base; 13. Hole; 14. Mounting pin; 15. Product PIN pin; 16. Mounting screw; 17. Screw hole; 18. Product outer shell limiting post; 19. PCB board. Detailed Implementation

[0034] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of this utility model, and to facilitate its implementation.

[0035] like Figures 1 to 11 As shown, this utility model provides a test fixture with PIN offset control, including a fixture support 10, a fixture probe plate 4, a PIN pin control plate 7 disposed on the fixture probe plate 4, and a movable pull-out alignment base 9 disposed on the fixture support 10 for placing a power module. The pull-out alignment base 9 is located below the PIN pin control plate 7. The PIN pin control plate 7 is provided with holes 13 corresponding to the positions of the PIN pins on the power module, and the fixture probe plate 4 is provided with probes.

[0036] Specifically, such as Figure 1 As shown, a clamping device is installed on the fixture support 10. The fixture clamping handle 1 is connected to the clamping device. The clamping device is a push-pull type clamping device with a clamping head that moves linearly. The clamping device is connected to the probe plate support 3 below. The fixture probe plate 4 is fixedly installed on the probe plate support 3. The probe plate support 3 is connected to two downward pressure guide posts 2. The two downward pressure guide posts 2 pass through two guide holes provided on the fixture support 10, and the downward pressure guide posts 2 guide the probe plate support 3. When the operator holds the fixture clamping handle 1 and operates the clamping device, the clamping device pushes the probe plate support 3 downward. The probe plate support 3 drives the fixture probe plate 4 and the PIN needle control plate 7 to move downward synchronously, thereby achieving downward pressure.

[0037] like Figures 1 to 3 and Figure 6As shown, by adding a PIN pin control plate 7 under the fixture probe plate 4, products (power modules) with misaligned PIN pins can be screened out before the test begins. The PIN pin control plate 7 adopts a front and back facing design. The front of the PIN pin control plate 7 is in close contact with the fixture probe plate 4. When locked, the probe is in the corresponding pin position. The hole 13 set on the back of the PIN pin control plate 7 corresponds to the position of the product's PIN pin. The hole 13 is a through hole set on the PIN pin control plate 7. When the probe plate bracket 3 drives the fixture probe plate 4 and the PIN pin control plate 7 to press down, the PIN pin on the product passes through the hole 13 of the PIN pin control plate 7 and contacts the fixture probe. If the PIN pin on the product is misaligned, the misaligned PIN pin cannot pass through the hole 13 and cannot contact the probe, thus controlling out products with misaligned PIN pins.

[0038] As a preferred option, the PIN pin control board 7 is made of FR4 board material, which is sturdy and durable. The front side is provided with probe holes and the back side is provided with PIN pin holes 13. The different design on both sides effectively prevents the PIN pin from not contacting the probe after passing through the hole 13.

[0039] The product's PIN pin diameter is 0.8mm, the diameter of hole 13 on the PIN pin control board 7 is 1.2mm, and the customer's installation size is 1.5mm. For products where the PIN pin can pass through hole 13, it can be guaranteed that the PIN pin of the product body will not be misaligned.

[0040] like Figure 1 , Figure 4 and Figure 8 As shown, a positioning pin 5 is provided on the fixture probe plate 4. The positioning pin 5 passes through the PIN pin control plate 7 and is configured to be inserted into the screw hole 17 on the power module.

[0041] like Figure 1 , Figure 4 and Figure 8 As shown, four positioning pins 5 are provided in a rectangular arrangement and are vertically positioned. By adding four positioning pins 5 to the fixture probe plate 4, the four positioning pins 5 are precisely engaged within the screw posts of the product housing. When the fixture probe plate 4 is pressed down, the positioning pins 5 first engage with the product screw holes 17, and then the probe contacts the product pins, improving the product positioning accuracy and preventing the product pins from becoming misaligned due to the pressure of the fixture.

[0042] Preferably, the positioning pin 5 is made of stainless steel, which is not easily worn. The positioning pin 5 and the fixture probe plate 4 are installed by insertion, with the insertion depth of the positioning pin 5 > 10mm to ensure the perpendicularity of the positioning pin 5. The machining accuracy of the positioning pin 5 is 0.05mm, and the diameter of the positioning pin 5 is 2.6mm. The screw hole 17 on the product shell has a diameter of 2.65mm. By using the positioning pin 5 for priority positioning, it can effectively avoid product misalignment and prevent the probe from pressing the product PIN pins off-center due to large tolerances.

[0043] like Figure 1 , Figure 10 and Figure 11 As shown, the fixture support 10 is equipped with base guide bars 8 for guiding the pull-out alignment base 9. The pull-out alignment base 9 is located between two base guide bars 8, which are horizontally positioned. Each base guide bar 8 has a groove for the pull-out alignment base 9 to be inserted into. The pull-out alignment base 9 moves horizontally. By using the method of removing the base to place the product and then inserting the pull-out alignment base 9 to press down the probe plate, the risk of collision between the product's PIN pins and the fixture probes is avoided, and operational portability is improved, eliminating the need to manually insert the product into the fixture.

[0044] As a preferred option, the pull-out alignment base 9 is made of FR4 fiberglass board, which is sturdy and wear-resistant. The base guide bars 8 on both sides are screwed to the base plate of the fixture bracket 10. The pull-out alignment base 9 can be moved in and out by locking it in the sliding groove of the base guide bar 8. The pull-out alignment base 9 has base guide bars 8 with a length of 60mm at both ends, which not only ensures that the base cannot be pulled out, but also ensures that the product position is exactly aligned with the fixture probe plate 4 above.

[0045] A pull-out alignment base 9 is adopted, and the pull-out alignment base 92 has a locking groove on its side. During operation, the pull-out alignment base 9 is pulled out, the product is placed on it, and then the pull-out alignment base 9 is pushed in all the way to press down the probe plate to start the operation. This design not only avoids the risk of the product PIN needle colliding with the fixture probe, but also improves the ease of operation and portability.

[0046] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A test fixture with PIN offset control, comprising a fixture support and a fixture probe plate, characterized in that: It also includes a PIN pin control plate disposed on the fixture probe plate and a pull-out alignment base disposed on the fixture bracket for placing the power module. The pull-out alignment base is located below the PIN pin control plate, and the PIN pin control plate is provided with holes corresponding to the positions of the PIN pins on the power module.

2. The test fixture with PIN pin offset control according to claim 1, characterized in that: The fixture probe plate is provided with a positioning pin, which passes through the PIN pin control plate and is configured to be inserted into the screw hole on the power module.

3. The test fixture with PIN pin offset control according to claim 2, characterized in that: Multiple positioning pins are provided.

4. The test fixture with PIN offset control according to claim 3, characterized in that: There are four positioning pins, which are arranged in a rectangular pattern.

5. The test fixture with PIN offset control according to claim 3, characterized in that: The positioning pin is made of stainless steel.

6. The test fixture with PIN pin offset control according to any one of claims 1 to 5, characterized in that: The fixture support is provided with base guide strips for guiding the pull-out alignment base, and the pull-out alignment base is located between two base guide strips.

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