TO-254AA metal packaging insulation resistance testing device and method

Abstract

The invention belongs to the field of insulation resistance testing, and relates to a TO-254AA metal packaging insulation resistance testing device and method. The device lead jacks on the jig base are used for insertion connection of the leading-out ends of the devices, and the device lead jacks provide necessary electrical connection points for testing. And the three-end leading-out end is used for an external circuit to carry out resistance test. During testing, the moving end of the needle planting plate is pushed, the elastic part is compressed through the moving end of the needle planting plate, and the device shell is arranged on the jig base, so that the leading-out end of the device can be conveniently arranged in the device lead jack in a penetrating manner. The moving end of the needle planting plate is released, and the elastic component pushes the moving end of the needle planting plate, so that the spring needles are in close contact with the surface of the device shell, and the insulation resistance test of the device shell is realized. Through the arrangement of the elastic component, the problem of excessive extrusion or insufficient contact between the spring needle and the device shell is avoided, the contact stability of the spring needle and the device shell is ensured, and meanwhile, the spring needle is prevented from scratching the device shell during detection.

Description

Technical Field

[0001] The invention belongs to the field of insulation resistance testing, and relates to a TO-254AA metal package insulation resistance testing device and method. Background Art

[0002] The magnitude of the insulation resistance of electronic components can sensitively reflect the insulation condition of the components, and can effectively detect general moisture, local severe moisture and penetrating defects of the components. As one of the most commonly used housings for power devices, the TO-254AA metal package is usually connected to structural components such as the chassis (the lowest potential) for heat dissipation during actual user use. When the three-terminal leads of the device are not completely insulated from the housing, the lowest potential of the shell will affect the normal use of the device. Therefore, it is of great practical significance to realize the insulation test between the leads and the housing of the TO-254AA metal package.

[0003] In the existing insulation test methods, manual measurement is often used, that is, an insulation test between the lead and the housing is realized by using a megohmmeter to contact through a test pen. Specifically as follows: 1. Since there is no lead-out port on the device housing, the current method mainly uses a direct contact method with a test pen to realize the insulation test between the lead and the housing. Because indirect testing cannot be carried out through a test fixture, the test pen is very likely to damage the appearance of the device; 2. When using a megohmmeter to test one device, the test pen needs to contact the lead and the housing 3 times, and after the insulation resistance test is completed, a set of DC parameter tests need to be carried out to ensure the device performance and test reliability, and the test efficiency is too low; 3. The test fixture and test adapter of the existing test equipment can only lead out the device pins as the lead-out ends, and cannot lead out the metal housing of the device. Therefore, the insulation resistance test cannot be directly realized.

[0004] This manual measurement method has problems of low test efficiency, poor protection effect on the appearance of the device and inability to directly realize the insulation resistance test, and there is a possibility of missing device testing, which seriously affects the reliability of the device. Summary of the Invention

[0005] The purpose of the invention is to provide a TO-254AA metal package insulation resistance testing device and method to solve the technical problems of low test efficiency, poor protection effect on the appearance of the device and inability to directly realize the insulation resistance test in manual measurement.

[0006] In order to achieve the above purpose, the invention adopts the following technical solutions: The invention discloses a TO-254AA metal package insulation resistance testing device, including: Fixture base, on which there are three device lead jacks for inserting and connecting the lead-out ends of devices, and each device lead jack is electrically connected to two three-terminal lead-out ends; Moving end of the pin-inserting board, which is slidably arranged on the fixture base and is also connected to the fixture base through an elastic component. There are two spring pins on the moving end of the pin-inserting board, and one end of each spring pin close to the device lead jack protrudes from the surface of the moving end of the pin-inserting board, and the spring pins are electrically connected to the housing lead-out ends.

[0007] Furthermore, the three device lead jacks are coplanar and equally spaced.

[0008] Furthermore, there is a fixed end of the pin-inserting board on the fixture base. The fixed end of the pin-inserting board is fixedly connected to the fixture base and is connected to the moving end of the pin-inserting board through an elastic component.

[0009] Furthermore, there is a first contact surface of the device housing on the fixture base, and the orifice of the device lead jack is located on the first contact surface of the device housing. There is a second contact surface of the device housing on the moving end of the pin-inserting board, and the protruding end of the spring pin is located on one side of the second contact surface of the device housing. Both the first contact surface of the device housing and the second contact surface of the device housing are flat surfaces, and the first contact surface of the device housing is perpendicular to the second contact surface of the device housing.

[0010] Furthermore, the spring pins are arranged in parallel and are perpendicular to the second contact surface of the device housing.

[0011] Furthermore, the end face of one end of the spring pin close to the device lead jack is a hemispherical contact surface.

[0012] Furthermore, the elastic component is a number of parallel springs, and the springs connect the fixed end of the pin-inserting board and the moving end of the pin-inserting board.

[0013] Furthermore, both the three-terminal lead-out ends and the housing lead-out ends are connected to a relay.

[0014] The present invention also discloses a method for testing the insulation resistance of a TO-254AA metal package, based on a TO-254AA metal package insulation resistance testing device, including the following steps: Push the moving end of the pin-inserting board, compress the elastic component through the moving end of the pin-inserting board, place the device housing on the fixture base, make the device lead-out end pass through the device lead jack, release the moving end of the pin-inserting board, and make the spring pin closely contact the surface of the device housing; Three-terminal contact test: Detect the contact impedance between the three device lead-out ends and the three device lead jacks; TO-254AA device function test: Apply the rated voltage to the TO-254AA device to detect the deviation of the working current; Pin three-terminal and housing lead contact test: Short-circuit the three device leads and then conduct a contact test with the housing lead to ensure normal physical connection before the insulation resistance test; Insulation resistance test: The insulation resistance test is realized by the method of applying voltage and measuring current; DC parameter test: Use the three-terminal leads to conduct DC parameter test to ensure the safety of the TO-254AA device after high-voltage test.

[0015] Furthermore, the rated voltage applied to the TO-254AA device is 500V.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The device lead jacks on the fixture base of the present invention are used for inserting and connecting the device leads. The device lead jacks provide necessary electrical connection points for testing. The three-terminal leads are used for connecting to the external circuit for resistance test. During the test, push the movable end of the needle-planting board. By compressing the elastic component through the movable end of the needle-planting board, place the device housing on the fixture base, facilitating the device leads to pass through the device lead jacks. Release the movable end of the needle-planting board, and the elastic component pushes the movable end of the needle-planting board, making the spring needle in close contact with the surface of the device housing, realizing the insulation resistance test of the device housing. The setting of the elastic component avoids the problems of excessive extrusion or insufficient contact between the spring needle and the device housing, ensures the stability of the contact between the spring needle and the device housing, and at the same time, avoids scratching the device housing during detection. The present invention realizes the insulation resistance test of the device housing, significantly improves the test efficiency, and avoids the damage to the device appearance caused by the test pen easily.

[0017] 2. Both the three-terminal leads and the housing leads of the present invention are connected to the relay, which is convenient for realizing the automatic test of the TO-254AA device and improving the test efficiency.

[0018] 3. The end face of the spring needle near the device lead jack is a hemispherical contact surface, which ensures close contact between the spring needle and the surface of the device housing while avoiding scratching the surface of the device housing.

[0019] 4. After placing the device housing on the fixture base, the method of the present invention sequentially performs three-terminal contact testing, TO-254AA device function testing, contact testing between the three terminals of the pins and the housing lead-out terminals, insulation resistance testing, and DC parameter testing. The three-terminal contact testing is used to ensure good contact of the device pins, the TO-254AA device function testing is used to ensure normal device function, the contact testing between the three terminals of the pins and the housing lead-out terminals is used to ensure normal physical connection before the insulation resistance testing, the insulation resistance testing is used to completely disconnect the housing from the three terminals of the pins, and the DC parameter testing is used to ensure the safety of the TO-254AA device after the high-voltage test. The method of the present invention can avoid electrostatic failure of the device caused by directly applying a large voltage when the device pins, the metal housing, and the test equipment are not in contact, and improve the safety of the testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a side view of the test fixture of the present invention; Figure 2 is a top view of the test fixture of the present invention; Figure 3 is a sectional view of the movable pin-inserting board of the present invention; Figure 4 is a schematic diagram of the electrical connection control of the housing lead-out terminal of the present invention; Figure 5 is a schematic diagram of the electrical connection control of the three-terminal lead-out terminal of the present invention; Figure 6 is a schematic diagram of the test flow of the present invention.

[0021] Wherein: 1. Fixture base; 2. Device lead-out terminal; 3. Movable pin-inserting board; 4. Spring pin; 5. Device lead socket; 6. TO-254AA device; 7. Device lead-out terminal; 8. Elastic member; 9. Movable end of the pin-inserting board; 10. Fixed end of the pin-inserting board; 11. Housing lead-out terminal; 12. Three-terminal lead-out terminal; 13. First contact surface of the device housing; 14. Second contact surface of the device housing; 15. Device housing; 16. Relay. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the description of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] The present invention will be further described in detail below with reference to the drawings: See Figure 1 , the present invention discloses a TO-254AA metal package insulation resistance test device, including: a fixture base 1 and a needle-planting plate mobile end 9; Three device lead jacks 5 are provided on the fixture base 1, and the device lead jacks 5 are used for the insertion connection of the device lead-out ends 2. The device lead jacks 5 provide necessary electrical connection points for testing. Each of the device lead jacks 5 is electrically connected to two three-terminal lead-out ends 12, and the three-terminal lead-out ends 12 are used for connecting to an external circuit for resistance testing. Among them, the fixture base 1 is the basic part of the test device.

[0025] The needle-planting plate mobile end 9 is slidably arranged on the fixture base 1. The needle-planting plate mobile end 9 is also connected to the fixture base 1 through an elastic member 8. Two spring needles 4 are provided on the needle-planting plate mobile end 9. One end of the spring needle 4 close to the device lead jack 5 protrudes from the surface of the needle-planting plate mobile end 9. The spring needle 4 is electrically connected to a housing lead-out end 11, and the housing lead-out end 11 is used for connecting to an external circuit for resistance testing. During testing, the needle-planting plate mobile end 9 is pushed, and the elastic member 8 is compressed through the needle-planting plate mobile end 9, and the device housing 15 is placed on the fixture base 1 to facilitate the device lead-out end 2 to pass through the device lead jack 5. The needle-planting plate mobile end 9 is released, and the elastic member 8 pushes the needle-planting plate mobile end 9 to make the spring needle 4 in close contact with the surface of the device housing 15, realizing the insulation resistance test of the device housing 15. The setting of the elastic member 8 avoids the problems of excessive extrusion or insufficient contact between the spring needle 4 and the device housing 15, ensures the stability of the contact between the spring needle 4 and the device housing 15, and at the same time, avoids scratching the device housing 15 by the spring needle 4 during detection. The present invention realizes the insulation resistance test of the device housing 15, significantly improves the test efficiency, and avoids damage to the device appearance caused by the test pen during testing.

[0026] Embodiment 1: See Figure 1 AndFigure 2 , the present invention discloses a TO-254AA metal package insulation resistance test device, including: a fixture base 1 and a needle-planting plate mobile end 9; See Figure 2 , three device lead jacks 5 are provided on the fixture base 1, the three device lead jacks 5 are coplanarly arranged and equally spaced, the device lead jacks 5 are used for the insertion connection of the device lead-out ends 2, and each device lead jack 5 is electrically connected to two three-terminal lead-out ends 12 See Figure 5 ; See Figure 2 and Figure 3 , a needle-planting plate fixed end 10 is further provided on the fixture base 1, the needle-planting plate fixed end 10 is fixedly connected to the fixture base 1, and the needle-planting plate fixed end 10 is connected to the needle-planting plate mobile end 9 through an elastic member 8.

[0027] Preferably, the sliding member is composed of a slide rail and a slider, ensuring the stability of the sliding of the needle-planting plate mobile end 9 on the fixture base 1.

[0028] See Figure 1 and Figure 2 , a first contact surface 13 of the device housing is provided on the fixture base 1, the orifice of the device lead jack 5 is located on the first contact surface 13 of the device housing, a second contact surface 14 of the device housing is provided on the needle-planting plate mobile end 9, the protruding end of the spring pin 4 is located on one side of the second contact surface 14 of the device housing, both the first contact surface 13 of the device housing and the second contact surface 14 of the device housing are flat surfaces, and the first contact surface 13 of the device housing is perpendicular to the second contact surface 14 of the device housing.

[0029] The spring pins 4 are arranged in parallel, and the spring pins 4 are perpendicular to the second contact surface 14 of the device housing.

[0030] The end face of the spring pin 4 near the device lead jack 5 is a hemispherical contact surface, which can ensure the close contact between the spring pin 4 and the surface of the device housing 15 while avoiding scratching the surface of the device housing 15.

[0031] See Figure 1 and Figure 2 , the needle-planting plate mobile end 9 is slidably arranged on the fixture base 1, the needle-planting plate mobile end 9 is further connected to the fixture base 1 through an elastic member 8, two spring pins 4 are provided on the needle-planting plate mobile end 9, the end of the spring pin 4 near the device lead jack 5 protrudes from the surface of the needle-planting plate mobile end 9, and the spring pin 4 is electrically connected to an outer housing lead-out end 11.

[0032] See Figure 3 , the elastic member 8 is a plurality of parallel springs, and the springs connect the needle-planting plate fixed end 10 and the needle-planting plate mobile end 9.

[0033] See Figure 4 and Figure 5 Both the three-terminal lead-out terminal 12 and the housing lead-out terminal 11 are connected to the relay 16, which facilitates the automated testing of the TO-254AA device and improves the testing efficiency.

[0034] Based on the above structure, the present invention also discloses a method for testing the insulation resistance of a TO-254AA metal package. See Figure 6 and includes the following steps: Step 1: Push the movable end 9 of the needle-inserting plate. Compress the elastic member 8 through the movable end 9 of the needle-inserting plate. Place the device housing 15 on the fixture base 1, insert the device lead-out terminal 2 into the device lead jack 5, release the movable end 9 of the needle-inserting plate, and make the spring pin 4 in close contact with the surface of the device housing 15. Step 2: Three-terminal contact test: Detect the contact impedance between the three device lead-out terminals 2 and the three device lead jacks 5 to ensure good contact of the device pins. Step 3: TO-254AA device function test: Apply a rated voltage to the TO-254AA device to detect the working current deviation and ensure normal device function. Step 4: Contact test between the three pins and the housing lead-out terminal: Short-circuit the three device lead-out terminals 2 and then conduct a contact test with the housing lead-out terminal 11 to ensure normal physical connection before the insulation resistance test. Step 5: Insulation resistance test: Implement the insulation resistance test by the method of applying voltage and measuring current. Step 6: DC parameter test: Use the three-terminal lead-out terminal 12 to conduct the DC parameter test to ensure the safety of the TO-254AA device after high-voltage testing, and avoid electrostatic failure of the device caused by directly applying a large voltage when the device pins and the metal housing are not in contact with the test equipment.

[0035] Embodiment 2: This embodiment designs a special test fixture for insulation resistance based on the resources of automatic equipment to safely lead out the housing, designs an automatic test process, and realizes the tests of insulation resistance and DC parameters at one time, improving the test efficiency while ensuring the safety of the device under high-voltage conditions. The present invention adopts the following technical solutions: The special test fixture for insulation resistance is as shown in Figure 1 , Figure 2 and Figure 3 .

[0036] The present invention uses two round spring pins 4 to lead out from the device housing 15. When the round spring pins 4 contact the device housing 15, it can reduce the damage to the metal coating and ensure that the appearance meets the standard requirements. At the same time, the design of the two spring pins 4 can achieve Kelvin connection, ensuring the accuracy of the test. At the same time, the contact resistance test is carried out before the insulation test to ensure the full contact between the device housing 15 and the spring pins 4, ensuring the reliability of the insulation resistance test; A movable needle-inserting plate 3 is designed. When the movable needle-inserting plate 3 is pushed backward, the device lead-out end 2 is inserted into the device lead jack 5, avoiding scratches on the appearance caused by friction between the device housing 15 and the spring pins 4. After the device lead-out end 2 is inserted, the device housing 15 is in close contact with the spring pins 4 under the reaction force of the spring. This design ensures the reliability of the test while ensuring that the appearance of the device is not scratched.

[0037] The present invention discloses a dedicated circuit for insulation resistance testing, which realizes the automatic insulation resistance testing process by utilizing the resources of an automatic testing device.

[0038] Relays are used to connect the lead-out end of the test fixture housing and the three-terminal lead end to the resources of the automatic testing device, as shown in Figure 4 and [[ID= shown.

[0039] Based on the resources of the automatic testing device, an automatic insulation resistance testing process is designed, as shown in ​ shown. During testing, first, the three-terminal contact test of the device pins and the device function test are carried out to ensure good contact of the device pins and normal device function. Then, the three-terminal pins of the device are short-circuited through a relay to carry out the device metal housing contact test and the insulation resistance test. This testing method can avoid electrostatic failure of the device caused by directly applying a large voltage when the device pins and the metal housing are not in contact with the testing equipment.

[0040] This set of processes can simultaneously test the insulation resistance and the electrical parameters of the device in one test program, improving the test efficiency. In addition, it can also realize the real-time monitoring of the device performance after the insulation resistance test, ensuring the test safety.

[0041] Compared with the existing technology, the present invention is beneficial to the accurate measurement of the insulation resistance of TO-254AA metal packaging, improving the test safety and production efficiency during mass production testing and saving the test cost.

[0042] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the present invention.

Claims

1. The TO-254AA metal package insulation resistance testing device is characterized in that Including: A fixture base (1), on which there are three device lead jacks (5) for the insertion connection of the device lead-out ends (2), and each of the device lead jacks (5) is electrically connected to two three-terminal lead-out ends (12); A needle-planting plate mobile end (9) slidably arranged on the fixture base (1), and the needle-planting plate mobile end (9) is also connected to the fixture base (1) through an elastic member (8). There are two spring pins (4) on the needle-planting plate mobile end (9), and one end of the spring pin (4) close to the device lead jack (5) protrudes from the surface of the needle-planting plate mobile end (9), and the spring pin (4) is electrically connected to a housing lead-out end (11).

2. The TO-254AA metal package insulation resistance testing device according to claim 1, characterized in that The three device lead jacks (5) are coplanar and equally spaced.

3. The TO-254AA metal package insulation resistance testing device according to claim 1, wherein, On the fixture base (1), there is also a needle-planting plate fixed end (10) fixedly connected to the fixture base (1), and the needle-planting plate fixed end (10) is connected to the needle-planting plate mobile end (9) through an elastic member (8).

4. The TO-254AA metal package insulation resistance test device according to claim 1, wherein On the fixture base (1), there is a first contact surface (13) of the device housing, and the orifice of the device lead jack (5) is located on the first contact surface (13) of the device housing. On the needle-planting plate mobile end (9), there is a second contact surface (14) of the device housing, and the protruding end of the spring pin (4) is located on one side of the second contact surface (14) of the device housing. Both the first contact surface (13) of the device housing and the second contact surface (14) of the device housing are flat surfaces, and the first contact surface (13) of the device housing is perpendicular to the second contact surface (14) of the device housing.

5. The TO-254AA metal package insulation resistance testing device according to claim 4, characterized in that, The spring pins (4) are arranged in parallel and perpendicular to the second contact surface (14) of the device housing.

6. The TO-254AA metal package insulation resistance test device according to claim 1, characterized in that, The end face of the end of the spring pin (4) close to the device lead jack (5) is a hemispherical contact surface.

7. The TO-254AA metal package insulation resistance testing device according to claim 1, characterized in that, The elastic member (8) is a plurality of parallel springs connecting the needle-planting plate fixed end (10) and the needle-planting plate mobile end (9).

8. The TO-254AA metal package insulation resistance testing device according to claim 1, characterized in that, Both the three-terminal lead-out end (12) and the housing lead-out end (11) are connected to a relay (16).

9. The method for testing the insulation resistance of a TO-254AA metal package, based on the TO-254AA metal package insulation resistance testing device according to any one of claims 1 to 8, is characterized in that, Including the following steps: Push the needle-planting plate mobile end (9) to compress the elastic member (8) through the needle-planting plate mobile end (9), place the device housing (15) on the fixture base (1), make the device lead-out end (2) pass through the device lead jack (5), and release the needle-planting plate mobile end (9) to make the spring pin (4) in close contact with the surface of the device housing (15); Three-terminal contact test: Detect the contact impedance between the three device lead-out ends (2) and the three device lead jacks (5); TO-254AA device function test: Apply a rated voltage to the TO-254AA device to detect the working current deviation; Pin three-terminal and housing lead-out end contact test: Short-circuit the three device lead-out ends (2) and then conduct a contact test with the housing lead-out end (11) to ensure normal physical connection before the insulation resistance test; Insulation resistance test: Realize the insulation resistance test by the method of applying voltage and measuring current; DC parameter test: The DC parameters are tested using the three-terminal lead-out (12) to ensure the safety of the TO-254AA device after a high-voltage test.

10. The TO-254AA metal package insulation resistance test method according to claim 9, characterized in that, The rated voltage applied to the TO-254AA device is 500V.

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