Clamp for testing reliability of flat-plate type power semiconductor device

Abstract

The utility model relates to a flat plate type power semiconductor device reliability test clamp comprising a pressure applying frame, the pressure applying frame is connected with a pressure applying structure and a lower pressure head preheating structure, the lower pressure head preheating structure supports a tested device, the pressure applying structure is connected with an upper pressure head staggered layer insulation structure, and the upper pressure head staggered layer insulation structure is connected with the lower pressure head preheating structure. The pressure applying structure can enable the upper pressure head staggered layer insulation structure to move downwards, and pressure is applied to the tested device through the upper pressure head staggered layer insulation structure; the beneficial effects of the utility model are that a pressure applying structure of a trapezoid screw-nut pair is adopted, so that the reliability of the test fixture aiming at long-time operation is effectively guaranteed. The layout of the preheating system is designed in the standard profile radiator, and the fan is designed behind the standard profile radiator for sufficient air cooling and heat dissipation of the radiator, so that the structure is more compact, simpler and more effective.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the test field of power semiconductor, concretely relates to flat plate type power semiconductor device reliability test fixture. BACKGROUND

[0002] At present flat plate type power semiconductor device is widely used as a mature electronic switch. In the device production process, the various parameters need to be tested, and the reliability test of the device is essential, such as high temperature blocking test, thermal cycle load test, etc. Such reliability test first needs to clamp the measured device in the fixture, and the fixture can provide certain high temperature preheating and heat dissipation conditions, and then according to the test standard, the external test power supply intermittently applies high voltage or large current to the measured device, and then the physical cooling is carried out, and so on. The measured device needs to be repeatedly tested in the above-mentioned test cycle, and the test cycle is two to three hours, and the test cycle is several tens of days. In the process, the measured device needs to be kept in a stable clamped state, so a stable and reliable test fixture needs to be provided to ensure long-term test operation. UTILITY MODEL CONTENTS

[0003] The utility model aims at providing a fixture capable of stably clamping flat plate type power semiconductor device and realizing reliability test.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the patent is a flat plate type power semiconductor device reliability test fixture, which comprises a pressure applying frame, a pressure applying structure and a lower head preheating structure connected to the pressure applying frame, the lower head preheating structure supports the measured device, the pressure applying structure is connected with an upper head staggered insulation structure, the pressure applying structure can move the upper head staggered insulation structure downward, and the pressure applying structure can apply pressure to the measured device through the upper head staggered insulation structure;The center position of the sliding plate is connected with a rotatable trapezoidal lead screw, the trapezoidal lead screw moves axially when rotating, and then controls the vertical movement of the sliding plate;The lower head preheating structure comprises a radiator and a fan, the measured device is placed on the radiator, the lower electrode of the measured device is led out through the radiator, the radiator is built-in with a heating rod and a thermocouple, the heating rod and the thermocouple heat the measured device when working, the fan is located at the side of the radiator, and the fan can blow the radiator and the measured device, so that the temperature of the radiator and the measured device is reduced.

[0005] Further, the pressure applying structure and the upper head staggered insulation structure are connected with a leveling structure, and the leveling structure is located above the upper head staggered insulation structure.

[0006] Further, the leveling structure comprises a first isolation plate, the first isolation plate is connected with the upper head staggered insulation structure, the first isolation plate is connected with the sliding plate through a third screw rod, the upper surface of the first isolation plate is provided with a conical hole, and the conical hole is provided with a steel ball.

[0007] Further, the third screw is sleeved with a buffer spring, and the buffer spring is located between the sliding plate and the first isolation plate.

[0008] Further, the upper pressing head staggered insulation structure comprises a second isolation plate and an upper electrode, the upper electrode is connected to the second isolation plate, and the upper electrode can be pressed on the measured device after moving downward.

[0009] Further, the pressing frame comprises a bottom plate and a top plate, and the bottom plate and the top plate are connected through two guide rods.

[0010] The beneficial effects of the patent are: the pressure applying structure of the trapezoidal screw nut pair effectively guarantees the reliability of the test fixture for long time operation. The layout of the preheating system is designed in the standard profile radiator, and the fan is designed behind the radiator to provide sufficient air cooling for the radiator, so that the structure is more compact and simple and effective. BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 is the front view of the utility model;

[0012] Fig. 2 is the side view of the utility model;

[0013] Fig. 3 is the local enlarged view of the trapezoidal screw pressing end of the utility model;

[0014] Wherein, 1-top plate, 2-trapezoidal nut, 3-fourth screw, 4-sliding plate, 5-fifth screw, 6-linear bearing, 7-fan, 8-guide rod, 9-heating baffle, 10-fan support, 11-sixth screw, 12-third isolation plate, 13-bottom plate, 14-fixed angle connecting piece, 15-radiator, 16-heating rod, 17-eighth screw, 18-thermocouple, 19-measured device, 20-upper electrode, 21-second isolation plate, 22-first isolation plate, 23-buffer spring, 24-third threaded rod, 25-second screw, 26-bearing end cover, 27-first screw, 28-trapezoidal screw. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. It should be understood that the preferred embodiments described herein are only used to explain and describe the present application, and are not used to limit the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. In the embodiments, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application.

[0016] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0017] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected; it can be electrically connected; it can be a hydraulic oil circuit connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0018] Referring to Figs. 1 to 3As shown, a flat plate type power semiconductor device reliability test fixture includes a pressing frame, the pressing frame includes a bottom plate 13 and a top plate 1, the bottom plate 13 and the top plate 1 are connected by two guide rods 8, so that the bottom plate 13 and the top plate 1 have a vertical spacing area, specifically, the two guide rods 8 are screwed into the bottom plate 13, the upper part of the two guide rods 8 has a step and a thread, the top plate 1 is installed on the step of the upper end of the guide rod 8, and then two nuts are used for fastening. In this way, the pressing frame forms a whole, and the pressing structure and the lower head preheating structure are arranged on the pressing frame, both of which are located in the vertical spacing area, the pressing structure is located above the lower head preheating structure, during testing, the device under test is placed on the lower head preheating structure, then pressure is applied to it, so that the position of the device under test is stable, and then the reliability test of the device under test is carried out.

[0019] Two linear bearings 6 are symmetrically installed in the two sides of the sliding plate 4 through hole shaft tight fit, and then are installed through the two guide rods 8.

[0020] The pressing structure includes a sliding plate 4, the sliding plate 4 is provided with symmetrically arranged linear bearings 6 which are tightly fitted through hole shafts, and the guide rods 8 pass through the linear bearings 6, so that the sliding plate 4 is connected with the guide rods 8 on the pressing frame, at this time, the sliding plate 4 can vertically slide in the vertical spacing area, the sliding plate 4 is connected with a trapezoidal screw rod 28, the trapezoidal screw rod 28 passes through the top plate 1, the lower surface of the top plate 1 is connected with a trapezoidal nut 2 through a first screw 27, and the trapezoidal screw rod 28 passes through the trapezoidal nut 2, the two form a screwed joint, when the trapezoidal screw rod 28 rotates, it can move axially, at this time, it can drive the sliding plate 4 to move vertically, the sliding plate 4 is connected with a leveling structure, and the leveling structure is connected with an upper head staggered insulation structure through the leveling structure, the leveling structure is located above the upper head staggered insulation structure, and both of them are located between the sliding plate 4 and the lower head preheating structure, when the sliding plate 4 moves downward, the upper head staggered insulation structure can move downward and finally press on the device under test;

[0021] The upper surface of the sliding plate 4 is provided with a stepped hole shaft at the center position, the stepped hole shaft is butt jointed with the lower end of the trapezoidal screw rod 28, the lower end of the trapezoidal screw rod 28 is provided with a ball bowl set 31, and a thrust bearing 32 is arranged between the lower end of the trapezoidal screw rod 28 and the stepped hole shaft, at this time, a bearing end cover 26 is butt jointed with the sliding plate 4 through a second screw 25, the bearing end cover 26 buckles the ball bowl set 31, the lower end of the trapezoidal screw rod 28 and the thrust bearing 32 on the sliding plate 4, when the trapezoidal screw rod 28 is pressed downward, the lower rod end contacts the upper part of the thrust bearing 32 and exerts pressure; when the trapezoidal screw rod 28 is lifted upward to release pressure, the lower rod end contacts the ball bowl set 31, this design structure effectively reduces the friction loss of the rod end of the trapezoidal screw rod 28 during pressing and releasing, so that the fixture works more lightly and conveniently;

[0022] The above-mentioned leveling structure includes a first isolation plate 22, a tapered hole is arranged at the center of the upper surface of the first isolation plate 22, a steel ball 33 is assembled in the tapered hole, and when the first isolation plate 22 is connected with the sliding plate 4, the sliding plate 4 and the first isolation plate 22 clamp the steel ball 33, a third threaded rod 24 passes through the sliding plate 4, the third threaded rod 24 is connected with the first isolation plate 22, a buffer spring 23 is sleeved on the third threaded rod 24, and the first isolation plate 22 is connected with the upper pressure head staggered insulation structure;

[0023] The upper pressure head staggered insulation structure includes a second isolation plate 21 and an upper electrode 20, the second isolation plate 21 is located between the first isolation plate 22 and the upper electrode 20, the second isolation plate 21 is connected with the first isolation plate 22 through a fourth screw 3, and the upper electrode 20 is connected with the second isolation plate 21 through a fifth screw 5, after the sliding plate 4 moves downward, the upper electrode 20 also moves downward, and finally the upper electrode 20 is pressed on the measured piece, at this time, the measured piece is supported below by the lower pressure head preheating structure, so that the measured piece forms a clamped stable state;

[0024] The lower pressure head preheating structure includes a radiator 15, the radiator 15 is arranged on a third isolation plate 12, the third isolation plate 12 is installed on a bottom plate 13, the radiator 15 is connected with the third isolation plate 12 through a fixed corner connecting piece 14 and a sixth screw 11, the radiator 15 is provided with a side opening, a heating rod 16 and a thermocouple 18 are inserted into the side opening, then a heating baffle 9 is connected with the side opening, and the heating baffle 9 is fastened on the radiator 15 by four eighth screws 17. Small holes are left on the heating baffle 9 for the cables of the heating rod 16 and the thermocouple 18 to pass through, and the cables of the two can be led out through the holes;

[0025] During the operation of the test fixture, first, the measured device 19 is placed on the radiator 15, then the trapezoidal screw rod 28 is controlled to rotate, the trapezoidal screw rod 28 moves downward, and then drives the sliding plate 4 and other components below to press downward until the upper surface of the measured device 19 is pressed, when the trapezoidal screw rod 28 is controlled to rotate, it can be manually controlled, for example, a handle 29 is fixed at the upper end of the trapezoidal screw rod 28, or a tool is inserted into the circular hole at the upper end of the trapezoidal screw rod 28, then the tool is rotated to drive the trapezoidal screw rod 28, or the upper end of the trapezoidal screw rod 28 is designed as an external hexagonal structure, and the trapezoidal screw rod 28 is driven to rotate by a power tool torque wrench. The above three methods can drive the trapezoidal screw rod 28 to rotate and move downward.

[0026] If necessary, the pressure value required by the device is added by a torque wrench, the upper surface of the measured device 19 is one of its electrodes, which is led out through the upper electrode 20; the lower surface of the measured device 19 is the other electrode of it, which is led out through the radiator 15, and then the heating function is started, the heating rod 16 and the thermocouple 18 can realize the accurate preheating temperature control of the measured device 19 before testing, and the external power supply is led out through the two electrodes to perform the reliability test on the current flowing through the measured device.

[0027] The fan 7 is installed on the bottom plate through the fan support 10, the fan support 10 is fixed on the bottom plate 13 through the seventh screw 30, and the fan 7 is located at the side of the radiator 15; when the fan 7 works, it can blow air to the radiator 15; when the measured device 19 generates heat and the temperature exceeds the specified temperature during the test, the fan 7 is started to cool the upper electrode 20, the measured device 19 and the radiator 15, so that the temperature of the measured device 19 is constant at the specified temperature, at which time the fan stops working, and then the current is passed to heat the device to the junction temperature, and the fan is restarted to cool down. Thus, the purpose of the reliability operation of the measured device is achieved.

[0028] In the above control, the fan, the heating rod and the thermocouple can be externally connected to an existing controller to realize the working state control.

[0029] In addition, in the present application, the upper electrode 20 of the test fixture is connected to the second isolation plate 21, and the second isolation plate 21 is connected to the first isolation plate 22, the first isolation plate 22 is connected to the sliding plate 4 through three third screws 24, the three third screws 24 pass through the sliding plate 4 and the corresponding buffer spring 23 and are connected to the first isolation plate 22, and by adjusting the connection depth of the three third screws 24 with the first isolation plate 22 respectively, the parallelism of the lower surface of the upper electrode 20 to the upper surface of the radiator 15 in the idle state can be ensured. The steel balls 33 are arranged in the conical holes in the center of the upper surface of the first isolation plate 22, and this structure can ensure the swing gap of the upper electrode in the circumferential direction when pressing. The disadvantage of insufficient parallelism between the lower surface of the upper electrode 20 and the upper surface of the radiator 15 due to cumulative assembly error when pressing is effectively overcome.

[0030] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A flat-type power semiconductor device reliability test fixture, comprising a pressure frame, characterized in that: The pressure applying frame is connected with a pressure applying structure and a lower pressing head preheating structure, the lower pressing head preheating structure supports the measured device, the pressure applying structure is connected with an upper pressing head staggered insulation structure, the pressure applying structure can move the upper pressing head staggered insulation structure downwards, and the upper pressing head staggered insulation structure applies pressure to the measured device; The pressure applying structure comprises a sliding plate, a rotatable trapezoidal lead screw is connected to the center position of the sliding plate, and the trapezoidal lead screw controls the vertical movement of the sliding plate when rotating; The lower pressing head preheating structure comprises a radiator and a fan, the measured device is placed on the radiator, the lower electrode of the measured device is led out through the radiator, a heating rod and a thermocouple are built-in the radiator, and the heating rod and the thermocouple heat the measured device when working; The fan is located at the side of the radiator, and the fan blows air to the radiator and the measured device, so that the temperature of the radiator and the measured device is reduced.

2. A flat plate type power semiconductor device reliability test jig according to claim 1, characterized by: The pressure applying structure is connected with a leveling structure and the upper pressing head staggered insulation structure, and the leveling structure is located above the upper pressing head staggered insulation structure.

3. A flat plate type power semiconductor device reliability test jig according to claim 2, characterized by: The leveling structure comprises a first isolation plate, the first isolation plate is connected with the upper pressing head staggered insulation structure, the first isolation plate is connected with the sliding plate through a third screw rod, a tapered hole is arranged on the upper surface of the first isolation plate, and a steel ball is arranged in the tapered hole.

4. A flat plate type power semiconductor device reliability test jig according to claim 3, characterized by: A buffer spring is sleeved on the third screw rod, and the buffer spring is located between the sliding plate and the first isolation plate.

5. The reliability test fixture for a planar power semiconductor device according to claim 1 or 3, characterized in that: The upper pressing head staggered insulation structure comprises a second isolation plate and an upper electrode, the upper electrode is connected to the second isolation plate, and the upper electrode can be pressed on the measured device after moving downwards.

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