A kind of four corner patch structure's encapsulation rectifier bridge test fixture

Abstract

The application relates to a clamp for testing a packaging rectifier bridge with a four-corner patch structure and belongs to the field of auxiliary equipment for testing a rectifier bridge. The clamp comprises an electrode fixing seat, the top surface center of the electrode fixing seat is provided with a positioning groove, four electrodes are fixed on the electrode fixing seat, the end portions of the electrodes extend to the edges of the positioning groove, and two groups of the four electrodes are arranged on the opposite sides of the positioning groove. A probe circuit board is slidably arranged above the fixing seat, four probes are connected to the probe circuit board, and the bottoms of the probes are arranged directly above the four electrodes located at the edges of the positioning groove. The application not only solves the two core defects of a traditional test seat, but also optimizes operation efficiency, test compatibility, maintenance cost and the like, considers practicability and economy, can meet the high-precision test demand of large current of different specifications of packaging rectifier bridges, and is especially suitable for quality detection scenes in batch production.

Description

Technical Field

[0001] This application belongs to the field of auxiliary equipment for rectifier bridge testing, and specifically relates to a four-corner patch structure for testing a packaged rectifier bridge. Background Technology

[0002] As a core power electronic device that converts alternating current (AC) to direct current (DC), packaged rectifier bridges are widely used in switching power supplies, home appliances, industrial control equipment, and new energy equipment. Their electrical performance directly determines the power supply stability and lifespan of end products. Therefore, in the manufacturing process of packaged rectifier bridges, it is necessary to use specialized testing equipment to accurately test their electrical parameters in order to screen out unqualified products and ensure the quality of products leaving the factory. The testing stage has become a key quality control node in the production process of packaged rectifier bridges. Early rectifier bridge testing often used a dedicated test socket, whose core fixing structure was a combination design of "base + cover". During testing, the packaged rectifier bridge must first be placed into the positioning slot of the base, and then the cover must be manually fastened to achieve contact and fixation between the tube leads and the test electrodes; after the test is completed, the cover clips must be unlocked and the cover lifted in order to remove the rectifier bridge.

[0003] In actual batch testing scenarios, the locking and unlocking of the caps requires manual operation one by one. Especially for multi-station test benches, operators need to repeatedly perform the cycle of "opening the cap - placing the part - closing the cap" and "opening the cap - taking out the part - closing the cap". The loading and unloading of a single workpiece takes a long time. When the test volume reaches hundreds or even thousands of pieces / batch, the overall testing efficiency is greatly reduced.

[0004] Some glands use an interference fit snap-fit ​​design, which requires a lot of force to snap into place, which can easily cause the rectifier bridge legs to shift or bend. If the force is not applied properly when unlocking, it may also damage the gland snap-fit, further increasing the frequency of equipment maintenance and the risk of test interruption.

[0005] For high-precision parameter testing of packaged rectifier bridges, the industry is gradually adopting the Kelvin testing principle. The corresponding Kelvin test socket needs to be equipped with two electrodes for each leg to eliminate the interference of contact resistance on the test results. However, the existing Kelvin test socket has inherent limitations in its structural design, making it only suitable for low-current testing scenarios and unable to meet the testing requirements of high-power rectifier bridges.

[0006] Due to limitations in the internal space and electrode layout of the test socket, existing Kelvin test sockets mostly use needle-like or sheet-like electrodes, which can only contact one side of the packaged rectifier bridge pin. The contact area between a single electrode and the pin is only 1 / 5 to 1 / 3 of the pin's cross-sectional area. When the test current increases, the small contact area on one side leads to a high concentration of current density, generating a large amount of Joule heat at the contact point between the electrode pin and the pin. Long-term use can easily cause oxidation of the gold plating on the pin and melting of the metal substrate, ultimately rendering the entire test socket unusable.

[0007] Meanwhile, single-sided contact places extremely high demands on the flatness and cleanliness of the tube legs. If there is an oxide layer, oil stains, or slight deformation on the surface of the tube legs, it can easily lead to poor contact between the electrode and the tube legs, resulting in problems such as fluctuations in test data and misjudgment of unqualified products. Frequent shutdowns are required to clean the electrode and tube legs, further affecting the testing efficiency. In summary, among existing packaged rectifier bridge testing technologies, the pressure-capped test socket is limited by the cumbersome loading and unloading process, making it difficult to meet the efficiency requirements of batch testing; the Kelvin test socket, due to its structural defect of small contact area on one side, cannot be adapted to the high-current testing scenarios of high-power rectifier bridges, and has problems such as high maintenance costs and poor test reliability. Utility Model Content

[0008] The technical problem to be solved by this application is to overcome the shortcomings of the prior art and provide a test fixture for packaged rectifier bridges with a four-corner surface mount structure. This application not only specifically solves the two major defects of traditional test fixtures, but also optimizes them from the dimensions of operation efficiency, test compatibility and maintenance cost, taking into account practicality and economy. It can meet the high current and high precision test requirements of packaged rectifier bridges of different specifications, and is especially suitable for quality inspection scenarios in mass production.

[0009] The technical solution adopted by this application to solve its existing problems is: A test fixture for a packaged rectifier bridge with a four-corner patch structure includes an electrode holder. The top surface of the electrode holder has a positioning groove at its center. Four electrodes are fixed on the electrode holder, and the ends of the electrodes extend to the edge of the positioning groove. The four electrodes are arranged in pairs on opposite sides of the positioning groove.

[0010] A probe circuit board is slidably mounted above the mounting base. Four probes are connected to the probe circuit board, and the bottom of the probes is positioned directly above the four electrodes located at the edge of the positioning groove.

[0011] Furthermore, the probe circuit board is fixedly connected to the probe fixing plate.

[0012] Furthermore, the probe fixing plate is fixedly connected to the floating plate, the bottom of the electrode fixing seat is fixed with a base plate, at least two vertically arranged optical axes are fixed on the base plate, the floating plate is provided with through holes, the optical axes pass through the through holes, and the floating plate and the optical axes are slidably connected up and down.

[0013] Furthermore, a linear bearing is provided at the through hole of the floating plate, and the optical axis is inserted into the linear bearing.

[0014] A spring is fitted on the optical axis, with its upper and lower ends abutting against the bottom surface of the floating plate and the top surface of the base plate, respectively.

[0015] Furthermore, the bottom of the floating plate is equipped with screws, and the base plate is equipped with a micro switch.

[0016] When the probe moves to the lower dead center and together with the electrode clamps the lead of the packaged rectifier bridge, the screw triggers the micro switch.

[0017] Furthermore, an upper bracket is fixedly connected to the top of the optical axis.

[0018] Furthermore, a lighting lamp is connected to the bottom of the upper bracket via a lamp holder, and a power supply device for supplying power to the lighting lamp is fixed on the upper bracket.

[0019] Furthermore, a handle is fixed to the front end of the probe fixing plate.

[0020] Furthermore, the electrode holder is provided with a groove, the electrode is inserted into the groove, and a detachable electrode pressure plate is placed on top of the groove.

[0021] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application abandons the traditional pressure cap design of the test holder and adopts a linkage structure of floating plate and spring reset. The operator only needs to hold the handle and press down to complete the clamping. After the test, the handle is released and the spring will automatically push the floating plate and probe to reset upward. There is no need to manually open and close the pressure cap. Compared with the cumbersome operation of traditional pressure caps that require repeated fastening and unlocking, the loading and unloading time is reduced by more than 60%, which is especially suitable for continuous operation in batch testing scenarios.

[0022] (2) The long, open design of the positioning slot, combined with the adjustable positioning stop, can quickly adapt to packaged rectifier bridges of different lengths without repeatedly adjusting the size of the test stand. The lighting at the bottom of the upper bracket can accurately illuminate the positioning area, avoiding workpiece alignment deviations caused by insufficient light. Operators can intuitively confirm the contact status between the tube legs and the electrodes, further reducing the time for picking up and adjusting, and improving the operational error tolerance.

[0023] (3) The bidirectional contact structure of the long strip gold-plated brass electrode and the flat-head spring probe is adopted, so that the upper and lower surfaces of the tube legs of the packaged rectifier bridge are clamped at the same time. Compared with the Kelvin test socket which only contacts one side, the contact area is increased by 3-5 times, which can stably carry high current test and avoid the problem of pin overheating caused by excessive local current density.

[0024] (4) The bidirectional contact between the top and bottom can effectively avoid the abnormal conduction caused by oxidation and contamination when contacting one side, reduce contact resistance interference, and ensure the accuracy of test data. At the same time, the gold-plated brass electrode and the gold-plated flat-head spring probe are both general standard parts, with low procurement costs and convenient replacement. In contrast, the traditional Kelvin test socket requires the entire test socket to be replaced when the pins are damaged. This application only requires the replacement of worn electrodes or probes separately, reducing the maintenance cost of a single fixture by more than 70% and greatly extending the overall service life of the fixture.

[0025] (5) The screws at the bottom of the floating plate are linked with the micro switch on the base plate. The micro switch will only trigger the test command when the probe moves down to the lower stop point and the tube leg is stably clamped, which effectively avoids test interruption or data distortion caused by loose clamping, and is especially suitable for process standardization in automated batch testing scenarios.

[0026] (6) The design of the 10P aviation plug makes it easier to connect the fixture and the tester. When changing different models of fixtures, there is no need to connect the wires one by one. One person can complete the replacement, saving equipment debugging time. The cooperation between the optical axis and the linear bearing ensures that the floating plate slides smoothly. The continuous elastic force of the spring can maintain the clamping stability. Even if it is used at high frequency for a long time, it is not easy to cause mechanical jamming. It is suitable for different testing environments such as factory workshops and laboratories. Attached Figure Description

[0027] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a structural diagram of a test fixture for a four-corner surface-mount packaged rectifier bridge according to this application. Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle. Figure 3 This is a front view of a test fixture for a four-corner patch structure packaged rectifier bridge according to this application.

[0029] In the diagram: 1-Upper bracket, 2-Optical axis, 3-Linear bearing, 4-Spring, 5-Probe circuit board, 6-Baffle, 7-Handle, 8-Electrode, 9-Electrode mounting base, 901-Positioning groove, 10-Base plate, 11-Electrode pressure plate, 12-Foot pad, 13-Positioning stop bar, 14-Probe mounting plate, 15-Lighting lamp, 16-Lamp holder, 17-Power supply device, 18-Probe, 19-Floating plate, 20-Screw, 21-Micro switch, 22-Encapsulated rectifier bridge, 2201-Pipe leg. Detailed Implementation

[0030] The attached figure shows a preferred embodiment of the test fixture for a four-corner patch structure packaged rectifier bridge. The following is a more detailed description of this application in conjunction with the attached figure.

[0031] Depend on Figure 1 as well as Figure 3As shown, a test fixture for a four-corner surface-mount packaged rectifier bridge includes an electrode holder 9, with a positioning groove 901 at the center of its top surface. The positioning groove 901 is elongated, open at both ends, and has a positioning stop 13 on each side of its center. The positioning stop 13 has several spaced-apart through holes, and the bottom surface of the positioning groove 901 has several spaced-apart threaded holes; the two are detachably connected by screws. The spacing between the two positioning stops 13 can be adjusted to accommodate packaged rectifier bridges 22 of different lengths.

[0032] Four electrodes 8 are fixed on the electrode holder 9. The ends of the electrodes 8 extend to the edge of the positioning groove 901. The four electrodes 8 are arranged in pairs on opposite sides of the positioning groove 901.

[0033] In this embodiment, the electrode holder 9 has a groove, the electrode 8 is fitted inside the groove, and a detachably connected electrode pressure plate 11 covers the groove. Furthermore, the electrode pressure plate 11 is detachably connected to the electrode holder 9 by screws.

[0034] A probe circuit board 5 is slidably mounted above the fixed base 9. Four probes 18 are connected to the probe circuit board 5. The bottom of the probes 18 is positioned directly above the four electrodes 8 located at the edge of the positioning groove 901.

[0035] Depend on Figure 2 As shown, the packaged rectifier bridge 22 is fitted inside the positioning groove 901, and its four legs 2201 rest on the four electrodes 8 located at the edge of the positioning groove 901. The probe 18 moves down, and its bottom surface abuts against the upper end surface of the legs 2201 of the packaged rectifier bridge 22. In this way, the upper and lower end surfaces of the legs 2201 can abut against the probe 18 and the electrodes 8 respectively, increasing the contact area of ​​the legs 2201.

[0036] Directly connecting the upper and lower surfaces of pin 2201 avoids poor contact caused by oxidation or contamination at a single contact point, thus obtaining more accurate conductivity measurement values. For high-power packaged rectifier bridges 22, pin 2201 is typically thicker; multiple connections ensure uniform current distribution and prevent localized overheating or measurement errors. In actual circuits, pin 2201 of packaged rectifier bridges 22 is often connected to the PCB board via soldering or crimping. Simultaneous contact of the upper and lower surfaces more accurately reflects the electrical performance under actual operating conditions. Therefore, when testing packaged rectifier bridges 22, connecting both the upper and lower surfaces of pin 2201 simultaneously ensures the accuracy and reliability of the test. This connection method effectively reduces interference from contact resistance and improves the stability of the detection signal.

[0037] This effectively solves the problems of existing technologies where each tube leg requires two electrode contacts, the electrode of the test socket can only contact one side of the tube leg, the electrode pin contact area of ​​the test socket is too small, and the test current is large, which easily burns out the pins and renders the device unusable over time.

[0038] In this embodiment, electrode 8 is a long strip of gold-plated bronze electrode, and probe 18 is a flat-headed spring probe. They contact the upper and lower surfaces of tube leg 2201, thus providing a sufficiently large contact area to meet the requirements of high-current testing. Furthermore, both the gold-plated bronze electrode and the gold-plated flat-headed spring probe are relatively inexpensive and readily available general-purpose parts, and even if they wear out over time, replacement is very simple.

[0039] In this embodiment, the probe circuit board 5 is fixedly connected to the probe fixing plate 14. The probe fixing plate 14 is fixedly connected to the floating plate 19. A base plate 10 is fixed to the bottom of the electrode fixing seat 9, and a rubber pad 12 is provided at the bottom of the base plate 10. At least two vertically arranged optical axes 2 are fixed on the base plate 10. The floating plate 19 has through holes through which the optical axes 2 pass, and the floating plate 19 and the optical axes 2 are slidably connected vertically. To improve the smoothness of sliding, a linear bearing 3 is provided at the through hole of the floating plate 19, and the optical axis 2 is inserted into the linear bearing 3.

[0040] To ensure that the probe 18 and electrode 9 are aligned at a distance when the encapsulated rectifier bridge 22 is not clamped, and to facilitate the installation of the encapsulated rectifier bridge 22, a spring 4 is fitted on the optical axis 2, with the upper and lower ends of the spring 4 abutting against the bottom surface of the floating plate 19 and the top surface of the base plate 10, respectively.

[0041] The bottom of the floating plate 19 is provided with a screw 20, and the base plate 10 is provided with a micro switch 21. When the probe 18 moves to the lower stop point and together with the electrode 8 clamps the tube leg 2201 of the packaged rectifier bridge 22, the screw 20 triggers the micro switch 21, and the valve issues a test command to perform the test.

[0042] The test fixture for the four-corner surface-mount packaged rectifier bridge connects to the tester via a 10-pin aviation connector. The connector includes eight electrode wires and two switch signal wires, which connect to the four probes 18, four electrodes 9, and the temperature control switch 21, respectively. Connecting to the tester via the aviation connector makes changing the test fixture more convenient, saving time and effort.

[0043] An upper bracket 1 is fixedly connected to the top of the optical axis 2. A lighting lamp 15 is connected to the bottom of the upper bracket 1 via a lamp holder 16. A power supply device 17 for supplying power to the lighting lamp 15 is fixed on the upper bracket 1. The power supply device 17 uses a rechargeable battery with a switch or a dry battery box containing dry batteries. The lighting lamp 15 provides illumination, facilitating accurate and quick handling of the encapsulated rectifier bridge 22 by the operator.

[0044] A handle 7 is fixed to the front end of the probe fixing plate 14. A baffle 6 is provided between the handle 7 and the probe fixing plate 14. The baffle 6 and the positioning pin on the probe fixing plate 14 together limit and position the probe circuit board 5 and the probe 18 to ensure the position of the probe 18.

[0045] The test clamping steps for packaged rectifier bridge 22 are as follows: S01. Preparation and adjustment before clamping: The operator first checks the fixture status to confirm that the spring 4 is in a naturally extended state, and that the probe 18 is arranged at a distance from the electrode 8 under the action of the spring force to ensure that there is enough space for the packaged rectifier bridge 22. Based on the length of the rectifier bridge 22 to be tested, loosen the screws on the positioning strips 13, adjust the distance between the two positioning strips 13 along the threaded hole on the bottom surface of the positioning groove 901 to match the length of the rectifier bridge, and then tighten the screws to fix the positioning strips 13. Turn on the power supply device 17, and the lighting 15 will light up, providing illumination for the positioning slot 901 area, making it easier to observe the placement position. Confirm that the fixture is connected to the tester via the 10P aviation connector, the electrode wires and switch signal wires are connected correctly, and the micro switch 21 is in the untriggered state. S02, Placement of the packaged rectifier bridge: The operator holds the encapsulated rectifier bridge 22, aligns it with the positioning groove 901 of the electrode holder 9, and smoothly inserts it into the groove, ensuring that the four legs 2201 of the rectifier bridge are accurately placed on the four electrodes 8 at the edge of the positioning groove 901, and that the legs 2201 are completely in contact with the upper surface of the electrodes 8. With the help of the illumination lamp 15, observe the placement of the tube leg 2201 to ensure that there is no offset or tilt. The positioning bar 13 plays a limiting role at both ends of the rectifier bridge to prevent lateral displacement during the test. S03, Clamping action execution: The operator holds the handle 7 and applies downward pressure, causing the probe fixing plate 14 and the floating plate 19 to slide downward along the optical axis 2. The linear bearing 3 ensures that the sliding process is smooth and without jamming. When the floating plate 19 moves down, it compresses the spring 4, and the spring 4 generates a reverse elastic force. As the pressure continues to be applied, the probe 18 descends synchronously with the probe circuit board 5 and gradually approaches the upper end face of the tube leg 2201 of the packaged rectifier bridge 22. Continue pressing down the handle 7 until the bottom surface of the probe 18 is in close contact with the upper surface of the tube leg 2201. At this time, the electrode 8 and the probe 18 together clamp and fix the tube leg 2201 from the top and bottom sides, achieving full contact between the upper and lower surfaces of the tube leg. During clamping, the baffle 6 and the positioning pin on the probe fixing plate 14 work together to ensure the accurate position of the probe circuit board 5 and the probe 18, and avoid poor contact caused by probe misalignment. S04, Test Triggering and State Maintenance: When the probe 18 moves to the lower stop point and completes clamping, the screw 20 at the bottom of the floating plate 19 triggers the micro switch 21 on the base plate 10, and the switch signal line transmits the clamping signal to the tester. After receiving the signal, the tester automatically issues a test command and performs electrical performance testing on the packaged rectifier bridge 22 through the electrode wires connected by the aviation plug. S05, Clamping release and workpiece removal: After the test is completed, the operator releases the handle 7. The spring 4 pushes the floating plate 19 upward along the optical axis 2 to reset under the action of elastic force. The probe 18 moves upward and separates from the upper end face of the tube leg 2201. After the floating plate 19 is reset to its initial position, the operator removes the encapsulated rectifier bridge 22 from the positioning slot 901, completing the single test clamping process. For continuous testing, simply repeat the above steps of placement, clamping, testing, and removal.

[0046] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A test fixture for a packaged rectifier bridge with a four-corner surface mount structure, characterized in that: Includes an electrode holder (9), the top surface of which is provided with a positioning groove (901), and four electrodes (8) are fixed on the electrode holder (9). The ends of the electrodes (8) extend to the edge of the positioning groove (901), and the four electrodes (8) are arranged in pairs on opposite sides of the positioning groove (901). A probe circuit board (5) is slidably provided above the fixed base (9). Four probes (18) are connected to the probe circuit board (5). The bottom of the probes (18) is located directly above the four electrodes (8) located at the edge of the positioning groove (901).

2. The test fixture for a four-corner patch structure packaged rectifier bridge according to claim 1, characterized in that: The probe circuit board (5) is fixedly connected to the probe fixing plate (14).

3. The test fixture for a four-corner patch structure packaged rectifier bridge according to claim 2, characterized in that: The probe fixing plate (14) is fixedly connected to the floating plate (19). The bottom of the electrode fixing seat (9) is fixed with a base plate (10). At least two vertically arranged optical axes (2) are fixed on the base plate (10). The floating plate (19) is provided with through holes. The optical axes (2) pass through the through holes. The floating plate (19) and the optical axes (2) are slidably connected up and down.

4. The test fixture for a four-corner patch structure packaged rectifier bridge according to claim 3, characterized in that: A linear bearing (3) is provided at the through hole of the floating plate (19), and the optical axis (2) is inserted into the linear bearing (3); A spring (4) is fitted on the optical axis (2), and the upper and lower ends of the spring (4) abut against the bottom surface of the floating plate (19) and the top surface of the base plate (10), respectively.

5. The test fixture for a four-corner patch structure packaged rectifier bridge according to claim 4, characterized in that: The bottom of the floating plate (19) is provided with screws (20), and the bottom plate (10) is provided with micro switches (21). When the probe (18) moves to the lower stop point and together with the electrode (8) clamps the pin (2201) of the packaged rectifier bridge (22), the screw (20) triggers the micro switch (21).

6. A test fixture for a four-corner patch structure packaged rectifier bridge according to claim 3, 4, or 5, characterized in that: The top of the optical axis (2) is fixedly connected to an upper bracket (1).

7. A test fixture for a four-corner patch structure packaged rectifier bridge according to claim 6, characterized in that: The bottom of the upper bracket (1) is connected to a lighting lamp (15) via a lamp holder (16), and a power supply device (17) for supplying power to the lighting lamp (15) is fixed on the upper bracket (1).

8. A test fixture for a four-corner patch structure packaged rectifier bridge according to claim 2, 3, 4, 5, or 7, characterized in that: A handle (7) is fixed to the front end of the probe fixing plate (14).

9. A test fixture for a four-corner patch structure packaged rectifier bridge according to claim 1, 2, 3, 4, or 5, characterized in that: The electrode holder (9) is provided with a groove, the electrode (8) is inserted into the groove, and the groove is covered with a detachable electrode pressure plate (11).

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