Auxiliary fixture for anti-radiation test of silicon carbide power chip

Abstract

This invention discloses an auxiliary fixture for radiation resistance testing of silicon carbide power chips, comprising a substrate with through holes and two movable plates. Each movable plate has a first end and a second end. The second end of at least one of the movable plates is movably connected to the substrate. A conductive pressure plate is connected to the side of the first end near the through hole. Two insulating supports are disposed opposite each other below the substrate. Each insulating support is connected to the first end of the corresponding movable plate via an axial displacement adjustment mechanism, which adjusts the distance between the insulating supports and the movable plates. Support platforms are respectively provided at opposite ends of the two insulating supports, and the pressure plates have pressing portions extending toward the support platforms. This auxiliary fixture ensures the stability of the silicon carbide power chip during radiation resistance testing and facilitates chip replacement, significantly reducing chip replacement time and thus improving the efficiency of radiation resistance testing.

Description

Technical Field

[0001] This invention relates to the field of chip testing auxiliary devices, and in particular to an auxiliary fixture for radiation resistance testing of silicon carbide power chips. Background Technology

[0002] Some silicon carbide (SiC) power chips, such as power devices based on wide-bandgap semiconductor SiC materials (e.g., SiC-based diodes, SiC-based MOSFETs), possess excellent physical and chemical properties, including high voltage resistance, high temperature resistance, high efficiency, and high frequency. However, when applied to aerospace equipment, they must withstand the impact of high-energy particle irradiation in space. Therefore, irradiation experiments are necessary to test the chip's radiation resistance. Single-event (or heavy-event) irradiation experiments are an important experimental method for simulating the high-energy ion flow radiation environment in space on the ground. They are a crucial verification method for the radiation-hardened design of SiC power chips and a necessary evaluation basis for new SiC power devices to obtain aerospace quality level certification. The large-scale high-energy particle irradiation test facility at the National Single-Event Irradiation Laboratory is the official testing facility for high-energy particle irradiation experiments on semiconductor power chips. It can provide preliminary testing and evaluation for semiconductor power chips using radiation-hardened technology. However, due to the influence of power-on time and scheduling, the number of single-event irradiation experiments per year is limited for each user with chip radiation resistance testing needs.

[0003] Because of the small size of bare chips and their electrodes, clamping and fixing the bare chips and positioning and connecting the electrodes are crucial for subsequent testing when conducting irradiation tests using the National High Energy Particle Irradiation Test Facility or High Energy Laser Simulation Irradiation Test Facility. Currently, there are no dedicated auxiliary fixtures, making chip loading and unloading cumbersome and severely impacting testing efficiency, thus failing to maximize the already limited opportunities for radiation resistance testing. Summary of the Invention

[0004] The purpose of this invention is to provide an auxiliary fixture for silicon carbide power chip radiation resistance testing that can clamp and fix chips of different sizes and provide quick replacement of the chip under test in the silicon carbide power chip radiation resistance testing process.

[0005] To achieve the above objectives, this invention discloses an auxiliary fixture for radiation resistance testing of silicon carbide power chips, comprising a substrate with a through hole having a long axis extending along its length. Two movable plates are disposed on the substrate at opposite ends of the through hole. Each movable plate includes a first end above the through hole and a second end connected to the substrate. The second end of at least one of the movable plates is movably connected to the substrate, allowing it to move along the long axis. A conductive pressure plate is connected to the side of the first end of each of the two movable plates near the through hole. Two insulating supports are disposed opposite each other below the substrate, each connected to the first end of the corresponding movable plate via an axial displacement adjustment mechanism. The axial displacement adjustment mechanism is used to adjust the distance between the insulating supports and the movable plates. Support platforms for supporting the edges of the chip under test are respectively provided at opposite ends of the two insulating supports, and pressing portions extending toward the support platforms are provided on the pressure plates.

[0006] Preferably, the axial displacement adjustment mechanism includes a connecting rod that passes through the first end of the movable plate and the through hole and connects to the insulating support. The connecting rod can slide relative to the movable plate to move the insulating support closer to or away from the movable plate. A cap is provided at the end of the connecting rod located above the movable plate.

[0007] Preferably, the axial displacement adjustment mechanism further includes a guide rod, the top of which is connected to the first end of the movable plate, the bottom of which passes through the insulating support, the guide rod being used to define the movement path of the insulating support, and an elastic element being provided between the bottom of the guide rod and the insulating support.

[0008] Preferably, the support platform protrudes from the insulating support, such that an L-shaped groove is formed between the end wall of the support platform and the insulating support.

[0009] Preferably, the insulating support is symmetrically provided with the support platform at both ends, and the two ends of the pressure plate are bent to form two pressing parts, which are respectively attached to the two end walls of the insulating support.

[0010] Preferably, the substrate is provided with two limiting plates, which are respectively located on the outer side of the two movable plates, and the two limiting plates are used to limit the movement trajectory of the movable plates.

[0011] Preferably, the limiting plate is also provided with a distance measurement mark.

[0012] Preferably, the substrate is further provided with a probe mounting base, on which an electrode probe is mounted.

[0013] Preferably, the probe mounting base includes a support screw, an adjusting nut, and a fastening nut; the upper end of the support screw passes through the substrate and is screwed to the adjusting nut, and the fastening nut is disposed at the lower end of the support screw, the fastening nut being used to clamp or release the tail end of the electrode probe.

[0014] Preferably, the probe mounting base further includes a retaining plate, which includes a first section and a second section connected by bending. The base plate is provided with a retaining hole that matches the first section of the retaining plate. The support screw is also fitted with a clamping nut and a compression spring. One end of the compression spring abuts against the base plate, and the other end of the compression spring abuts against the clamping nut. The clamping nut is located between the bottom of the compression spring and the fastening nut. The clamping nut is used to fix the second section of the retaining plate between the clamping nut and the fastening nut.

[0015] Compared with the prior art, the beneficial technical effects of the above-mentioned auxiliary clamp of the present invention are as follows:

[0016] 1. It not only ensures the stability of the chip during radiation resistance testing, but also facilitates the replacement of the chip under test, greatly shortening the chip replacement time, thereby improving the efficiency of chip radiation resistance testing and reducing time costs;

[0017] 2. The two pressure plates are conductive and can directly contact the electrode area of ​​the chip under test through the pressing part, thereby avoiding repeated wiring work when replacing the chip under test and further improving chip testing efficiency.

[0018] 3. The probe mounting base is small in size and flexible in adjustment, with the advantages of adjusting the length, extension direction and height of the electrode probe in three dimensions, and has a high cost performance. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the auxiliary fixture in an embodiment of the present invention.

[0020] Figure 2 for Figure 1 Top view.

[0021] Figure 3 for Figure 1 Side view.

[0022] Figure 4 for Figure 1 Diagram showing the connection structure between the two movable plates and the two insulating supports.

[0023] Figure 5 for Figure 4 Diagram showing the connection structure between a single movable plate and an insulating support.

[0024] Figure 6 for Figure 1 Planar structure diagram of the substrate.

[0025] Figure 7 This is a planar structural diagram of the back side of the chip in an embodiment of the present invention.

[0026] Figure 8 This is a planar structural diagram of the front side of the chip in an embodiment of the present invention. Detailed Implementation

[0027] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0028] This embodiment discloses an auxiliary fixture for radiation resistance testing of silicon carbide power chips, used in conjunction with testing instruments for clamping, fixing, and electrode connection of the silicon carbide power chip under test, thereby completing the radiation resistance test of the chip. Figures 1 to 6 The auxiliary clamp includes a base plate 1 with a rectangular through hole 10. The through hole 10 has a long axis (first axis L1) extending along its length. Two movable plates 2 are respectively located at opposite ends of the through hole 10 on the base plate 1. Each movable plate 2 includes a first end 20 above the through hole 10 and a second end 21 above and connected to the base plate 1. The second end 21 of at least one of the movable plates 2 is movably connected to the base plate 1, allowing the movable plate 2 to move along the long axis L1, thereby adjusting the relative distance between the two movable plates 2. In this embodiment, the second ends 21 of both movable plates 2 are movably connected to the base plate 1. Specifically, the second end 21 of the movable plate 2 is provided with a sliding shaft 22, and the base plate 1 is provided with a sliding groove 11 adapted to the sliding shaft 22. When the movable plate 2 is pushed or pulled, the movable plate 2 moves along the sliding groove 11 via the sliding shaft 22. Additionally, a locking nut may be provided on the sliding shaft 22 to fix the movable plate 2 in the target position.

[0029] A conductive pressure plate 3 is connected to the side of the first end 20 of the two movable plates 2 near the through hole 10. When the movable plate 2 moves, it drives the pressure plate 3 on it to move synchronously.

[0030] Two insulating supports 4 are disposed opposite each other on the lower part of the substrate 1. The two insulating supports 4 are respectively connected to the first end 20 of the corresponding movable plate 2 through an axial displacement adjustment mechanism. Therefore, when the movable plate 2 moves, the insulating supports 4 connected to it also move synchronously. The axial displacement adjustment mechanism is used to adjust the distance between the insulating supports 4 and the movable plate 2. In this embodiment, the insulating supports 4 can move closer to or further away from the movable plate 2 along the second axis L2, which is perpendicular to the first axis L1. In addition, the opposite ends of the two insulating supports 4 are respectively provided with a support platform 40 for supporting the front edge of the chip M under test. The pressure plate 3 is provided with a pressing part 30 that bends downward and extends toward the support platform 40. The width of the support platform 40 is preferably such that it can just support the chip M without obstructing the front electrode area of ​​the chip M.

[0031] To facilitate the explanation of the working principle of the above-mentioned auxiliary fixture, the structure of the chip M to be tested will first be described, such as... Figure 7 and Figure 8 The chip M is a power device, comprising a substrate M0. The back side edges of the substrate M0 have first electrode regions M1, corresponding to the drain of chip M. The front side of the substrate M0 has a second electrode region M2 and a third electrode region M3. The second electrode region M2 corresponds to the source of chip M, and the third electrode region M3 corresponds to the gate of chip M. The back side of the substrate M0 has an irradiation region M4, which is the silicon carbide substrate region on the back side of the substrate M0 after the metal layer has been removed. In this embodiment, the substrate M0 has a thin, square sheet structure.

[0032] When performing irradiation testing on chip M using this auxiliary fixture, firstly, the relative distance between the two movable plates 2 is adjusted according to the current size and width of the chip M under test, so that the distance between the support platforms 40 on the two insulating supports 4 is approximately equal to the width of chip M. Then, the axial displacement adjustment structure drives the insulating supports 4 away from the movable plates 2, thereby opening the gap between the support platforms 40 and the pressing part 30. Next, chip M is placed between the two support platforms 40. Then, under the action of the axial displacement adjustment mechanism, the two insulating supports 4 move closer to the movable plates 2, so that the pressing part 30 of the pressure plate 3 presses against the first electrode area M1 of chip M, completing the loading of chip M. This ensures the stability of chip M during radiation resistance testing and facilitates the replacement of chip M under test, significantly shortening the chip M replacement time, thereby improving the efficiency of radiation resistance testing and reducing time costs. Furthermore, before starting the test, only one wiring operation is required—connecting the pressure plate 3 to the corresponding output port on the testing instrument. When replacing chip M, there is no need to repeat the wiring, further improving testing efficiency.

[0033] like Figures 3 to 5The axial displacement adjustment mechanism includes a connecting rod 50, which passes through the first end 20 of the movable plate 2 and the through hole 10 and connects to the insulating support 4. The connecting rod 50 can slide relative to the movable plate 2 to move the insulating support 4 closer to or further away from the movable plate 2. In this embodiment, the insulating support 4 can be moved up and down by operating the connecting rod 50. For ease of operation, a cap 51 is provided at the end of the connecting rod 50 located above the movable plate 2.

[0034] Furthermore, the axial displacement adjustment mechanism also includes a guide rod 60. The top of the guide rod 60 is connected to the first end 20 of the movable plate 2, and the bottom of the guide rod 60 passes through the insulating support 4. The guide rod 60 is used to limit the movement path of the insulating support 4, and an elastic element 61 is provided between the bottom of the guide rod 60 and the insulating support 4. In this embodiment, when the elastic element 61 is in its naturally extended state, the support platform 40 abuts against the upper pressing part 30. When feeding is required, the cap part 51 above the connecting rod 50 is pressed first, causing the insulating support 4 to move down, so that the support platform 40 separates from the pressing part 30. At this time, the elastic element 61 is in a compressed state. Then, the chip M to be tested is placed on the support platform 40, and then the pressing force on the cap part 51 is removed. At this time, under the elastic restoring force of the elastic element 61, the insulating support 4 moves towards the movable plate 2 until the chip M on the support platform 40 abuts against the pressing part 30.

[0035] In addition, to prevent the chip M from shifting to one side on the support platform 40, an L-shaped slot 41 is formed between the support platform 40 and the end wall of the insulating support 4 (e.g., Figure 5 In this embodiment, two L-shaped slots 41 on the two insulating supports 4 define a pull-out channel for the chip M, facilitating loading and unloading.

[0036] Furthermore, due to the small size of chip M, to prevent the insulating support 4 from twisting and tilting during axial adjustment, which could cause chip M to detach, such as... Figure 4 The insulating support 4 has symmetrically arranged protruding support platforms 40 at both ends, and the two ends of the pressure plate 3 are bent to form two pressing parts 30, making the pressure plate 3 have an arc-shaped structure. The two pressing parts 30 are respectively attached to the two end walls of the insulating support 4. In this embodiment, since the pressure plate 3 is fixed on the movable plate 2, the tightly attached metal pressing parts 30 restrict the twisting and tilting of the insulating support 4. In this way, when the axial distance between the insulating support 4 and the movable plate 2 is precisely adjusted, the two insulating supports 4 can reliably clamp the chip M.

[0037] like Figure 1 , Figure 2 as well as Figure 6Two limiting plates 7 are provided on the base plate 1, located on the outer sides of the two movable plates 2 respectively. The two limiting plates 7 are used to limit the movement trajectory of the movable plates 2, thereby preventing the movable plates 2 from deviating during movement along the first axis L1. Furthermore, a distance measurement mark is also provided on the limiting plate 7. The distance between the two movable plates 2 can be precisely adjusted through this distance measurement mark.

[0038] like Figures 1 to 3 To facilitate the wiring of the source and gate of chip M, a probe mounting base 8 is also provided on the substrate 1, and an electrode probe J is mounted on the probe mounting base 8. In this embodiment, two probe mounting bases 8 are provided on the substrate 1, and an electrode probe J is mounted on each of the two probe mounting bases 8. When chip M is clamped on the insulating support 4, the two electrode probes J are pressed and positioned against the second electrode region (source) M2 and the third electrode region (gate) M3 of chip M, respectively.

[0039] Specifically, the probe mounting base 8 includes a support screw 80, an adjusting nut 81, and a fastening nut 82. The upper end of the support screw 80 passes through the base plate 1 and is screwed to the adjusting nut 81. The fastening nut 82 is located at the lower end of the support screw 80 and is used to clamp or release the tail end of the electrode probe J. In this embodiment, there are two fastening nuts 82, namely an upper nut 820 and a lower nut 821, and the electrode probe J is clamped between the upper nut 820 and the lower nut 821. In this embodiment, the upper nut 820 is fixed after installation and positioning, and the electrode probe J can be tightened and released by adjusting the lower nut 821. By rotating the adjusting nut 81, the support screw 80 can be driven to move up and down, thereby adjusting the height of the electrode probe J.

[0040] Furthermore, such as Figure 1 and Figure 2The probe mounting base 8 also includes a clamping plate 83, which includes a first section 830 and a second section 831 connected by bending. The base plate 1 is provided with a clamping hole 12 that is adapted to the first section 830 of the clamping plate 83. The support screw 80 is also fitted with a clamping nut 84 and a compression spring 85. The compression spring 85 is fitted on the support screw 80. One end of the compression spring 85 abuts against the base plate 1, and the other end of the compression spring 85 abuts against the clamping nut 84. The clamping nut 84 is located between the bottom of the compression spring 85 and the upper nut 820. The clamping nut 84 is used to fix the second section 831 of the clamping plate 83 between the clamping nut 84 and the upper nut 820. In this embodiment, the upper end of the first segment 830 of the clamping plate 83 is located in the clamping hole 12 of the substrate 1 and can slide up and down, but cannot rotate. The second segment 831 of the clamping plate 83 is located between the clamping nut 84 and the upper nut 820. After the direction of the electrode probe J is adjusted to the correct position, the clamping nut 84 is tightened, thereby fixing the second segment 831 of the clamping plate 83 together with the upper nut 820 and the clamping nut 84. Since the first segment 830 of the clamping plate 83 is limited by the clamping hole 12 on the substrate, the rotation of the support screw 80 is prevented, thus ensuring the extension direction of the electrode probe J.

[0041] like Figures 1 to 8 The specific workflow of the auxiliary fixture disclosed in the above embodiments of the present invention is as follows:

[0042] S1: Connect the drain electrode signal of the test instrument to the two pressure plates 3 via the cable connection line and the locking nut;

[0043] S2: Connect the source and gate electrode signals of the test instrument to their respective electrode probes J via a cable connection and a locking nut;

[0044] S3: Referring to the distance measurement mark set on the limit plate 7, push and adjust the two movable plates 2 so that the distance between the end walls of the two insulating supports 4 is the width of the chip M, and then tighten the locking nut 23 (as shown). Figure 1 Fix two movable plates 2;

[0045] S4: Press the cap 51 above the first end 20 of the two movable plates 2 at the same time, so that the two insulating supports 4 move down an appropriate distance to make room for the chip M.

[0046] S5: After aligning the back of chip M with the irradiation direction, place it on the bottom support platform 40 of the two insulating supports 4;

[0047] S6: Loosen the cap 51. Under the elastic restoring force of the elastic element 61, the insulating support 4 moves upward. The chip M is clamped by the support platform 40 and the pressing part 30 of the pressure plate 3. At the same time, the drain electrode signal of the test instrument is connected to the first electrode area M1 of the chip M.

[0048] S7: Adjust the electrode probes J on the two probe mounting bases 8 according to the current usage environment, so that the two electrode probes J respectively abut against the second electrode area M2 and the third electrode area M3 on the front side of the chip M.

[0049] S8: Place the entire substrate 1 face up on the irradiation equipment test stage, align the irradiation area on the back of the chip M with the irradiation direction of the irradiation device, and then operate the test instruments and irradiation device to start the irradiation test experiment.

[0050] In addition, the specific adjustment of electrode probe J in step S7 above includes the following steps:

[0051] S70: Loosen the lower nut 821 of the fastening nut 82, and at the same time loosen the clamping nut 84. Manually adjust the length and direction of the electrode probe J so that the tip of the electrode probe J is aligned with the second electrode area M2 and the third electrode area M3 corresponding to the front of the core.

[0052] S71: Tighten the lower nut 821 of the fastening nut 82 to fix the length of the electrode probe J, and at the same time tighten the clamping nut 84 to fix the second section 831 of the clamping plate 83 on the probe mounting base 8, so as to prevent the probe mounting base 8 from rotating as a whole and causing the electrode probe J to deviate in direction.

[0053] S72: Rotate the adjusting nut 81 to adjust the height of the electrode probe J so that the tip of the electrode probe J abuts against and presses against its corresponding second electrode area M2 and third electrode area M3.

[0054] The aforementioned auxiliary fixture allows for rapid replacement of the next chip M after testing, ensuring the stability of chip M during testing and the reliability of electrode terminal connections. It also shortens chip M replacement time, accelerates overall testing speed, and improves economic efficiency. Furthermore, the electrode probe J is adjustable in length, angle, and height, ensuring stable and reliable contact and pressure between the electrode probe J and the chip M electrodes.

[0055] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An auxiliary fixture for testing the radiation resistance of silicon carbide power chips, characterized in that, The device includes a substrate with a through-hole having a long axis extending along its length. Two movable plates are disposed on the substrate at opposite ends of the through-hole. Each movable plate includes a first end above the through-hole and a second end connected to the substrate. The second end of at least one of the movable plates is movably connected to the substrate, allowing it to move along the long axis. A conductive pressure plate is connected to the side of the first end of each movable plate near the through-hole. Two insulating supports are disposed opposite each other below the substrate. Each insulating support is connected to the first end of the corresponding movable plate via an axial displacement adjustment mechanism. Each opposite end of the two insulating supports has a support platform for supporting the edge of a chip under test. The axial displacement adjustment mechanism adjusts the distance between the insulating supports and the movable plates, such that the distance between the support platforms on the two insulating supports is approximately equal to the width of the chip under test. A pressing portion extending toward the support platform is provided on the pressure plate, and the pressing portion is used to press the chip under test located on the insulating support.

2. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 1, characterized in that, The axial displacement adjustment mechanism includes a connecting rod that passes through the first end of the movable plate and the through hole and connects to the insulating support. The connecting rod can slide relative to the movable plate to move the insulating support closer to or away from the movable plate. A cap is provided at the end of the connecting rod located above the movable plate.

3. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 2, characterized in that, The axial displacement adjustment mechanism further includes a guide rod, the top of which is connected to the first end of the movable plate, the bottom of which passes through the insulating support, the guide rod being used to limit the movement path of the insulating support, and an elastic element being provided between the bottom of the guide rod and the insulating support.

4. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 1, characterized in that, The support platform protrudes from the insulating support, so that an L-shaped groove is formed between the end wall of the support platform and the insulating support.

5. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 4, characterized in that, The insulating support has symmetrical support platforms at both ends, and the two ends of the pressure plate are bent to form two pressing parts, which are respectively attached to the two end walls of the insulating support.

6. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 1, characterized in that, Two limiting plates are provided on the base plate, and the two limiting plates are respectively located on the outside of the two movable plates. The two limiting plates are used to limit the movement trajectory of the movable plates.

7. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 6, characterized in that, The limiting plate is also equipped with a distance measurement mark.

8. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 1, characterized in that, The substrate is also provided with a probe mounting base, on which an electrode probe is mounted.

9. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 8, characterized in that, The probe mounting base includes a support screw, an adjusting nut, and a fastening nut; the upper end of the support screw passes through the substrate and is screwed to the adjusting nut, and the fastening nut is located at the lower end of the support screw, and the fastening nut is used to clamp or release the tail end of the electrode probe.

10. The silicon carbide power chip radiation resistance testing auxiliary fixture according to claim 9, characterized in that, The probe mounting base also includes a retaining plate, which includes a first section and a second section connected by bending. The base plate is provided with a retaining hole that matches the first section of the retaining plate. The support screw is also fitted with a clamping nut and a compression spring. One end of the compression spring abuts against the base plate, and the other end of the compression spring abuts against the clamping nut. The clamping nut is located between the bottom of the compression spring and the fastening nut. The clamping nut is used to fix the second section of the retaining plate between the clamping nut and the fastening nut.

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