CN220820058U - Pneumatic Kelvin test fixture - Google Patents

Abstract

A pneumatic Kelvin test fixture comprises an operation table, wherein the operation table is composed of a bracket, a fixed plate, a positioning plate, a spring probe, a cylinder, a tester trigger switch and a Kelvin tester connected with the operation table through a wire; the spring probe is fixed on the telescopic arm of the air cylinder, and is lifted and lowered by the telescopic arm of the air cylinder, and the spring probe contacts and disconnects a device to be tested, so that Kelvin connection and disconnection are realized, and meanwhile, a testing instrument is triggered, so that measurement is realized; the positioning plate is arranged on the operation table and used for fixing the device to be tested; the fixed plate of the spring probe is fixed with the telescopic arm of the air cylinder, the spring probe is arranged on the fixed plate of the spring probe, and the interval between the spring probes can be adjusted, so that the spring probe can be correctly pressed on a contact of a device to be tested; the device to be tested is placed on a positioning plate. The method is used in the field of semiconductor testing. The method can lighten the working intensity of operators, is simple and convenient to operate, ensures the consistency of test results of different operators, avoids error test data and improves the quality of products.

Description

Pneumatic Kelvin test fixture

Technical Field

The utility model relates to a semiconductor test fixture, in particular to a semi-automatic Kelvin (Kelvin) test fixture.

Background

Kelvin connection is a simplified version of Kelvin bridge, and is a bridge circuit measuring method invented by Kelvin medal (Williamsium Thomson), which can effectively eliminate the impedance of wiring and contact resistance. Often used to accurately measure electrical impedance or voltage. In the diode test, both the forward voltage drop VF and the reverse breakdown voltage VBR belong to the voltage measurement. For accurate measurement, the test instruments all use the kelvin wiring scheme, which makes the test fixture require kelvin connection.

The prior Kelvin pen has a pair of probes (pen points), and test information (such as internal resistance and other parameters) is output from a test interface of the pen after passing through a bridge circuit of the pen body. In mass testing, in order to reduce the working strength, an automated instrument such as an automatic tester is generally used. However, in small and medium batch tests, manual clamps such as Kelvin test clamps, kelvin pens and the like are generally used. However, as the number of measurements increases, personnel gradually fatigue, the test speed becomes slower, and the efficiency decreases. Meanwhile, due to fatigue of personnel, the contact between the clamp and the measured piece becomes unreliable (due to low intrinsic values of parameters such as internal resistance and the like), error data are easy to generate or the error exceeds the range, and when serious, a fire striking phenomenon is generated between the clamp and the measured piece, and the measured piece is damaged. In addition, the different modes of operation of the different persons bring about different measurement results.

Disclosure of utility model

The utility model aims to solve the problems that in the existing test of module products in medium and small batches, when Kelvin pens and Kelvin clamps are used for testing, the efficiency is reduced due to fatigue of personnel, and the problems of abnormality and even 'sparking' of measurement are caused. The utility model provides a pneumatic Kelvin test fixture, which is simpler to operate and saves labor; the measurement result is more reliable and stable.

The utility model aims at realizing the technical scheme that the pneumatic Kelvin test fixture comprises an operation table and a pedal; the operation desk is connected to the Kelvin tester through a wire by a bracket, a fixing plate, a positioning plate, a spring probe, a cylinder, a tester trigger switch; the spring probe is fixed on the telescopic arm of the air cylinder, and is lifted and lowered by the telescopic arm of the air cylinder, and the spring probe contacts and disconnects a device to be tested, so that Kelvin connection and disconnection are realized, and meanwhile, a testing instrument is triggered, so that measurement is realized; the positioning plate 5 is arranged on the operation table and is used for fixing the device to be tested; the fixed plate of the spring probe is fixed with the telescopic arm of the air cylinder, the spring probe 4 is arranged on the fixed plate 3 of the spring probe, the fixed plate 3 is provided with a groove, and the distance between the spring probes 4 is adjusted by adjusting the position of the spring probe 4 on the fixed plate 3, so that the spring probe can be correctly pressed on a contact of a device to be tested; the pedal is stepped down, and a device to be tested is placed on the positioning plate; positioning the position of the device to be tested according to the positioning point; and the pedal is loosened, and the telescopic arm at the lower end of the air cylinder drives the spring probe to fall along the erection track of the bracket, so that one-time measurement is automatically completed.

The position of the probe 4 on the fixed plate 3 is adjusted to be matched with the positioning plate 5, so that the test requirements of products with different sizes are met. The pedal is used for controlling a switch for driving the cylinder to work. The cylinder 1 is driven to descend by the pedal 7, the probe 4 is driven to descend, and the probe contacts a device to be tested.

The fixed plate 3 descends to the low position, the trigger switch 6 is closed, and the fixed plate is connected to the Kelvin tester through a wire to enable the Kelvin tester to work, namely, measurement is carried out once.

Firstly, the position of the probe 4 on the fixed plate 3 is adjusted to be matched with the positioning plate 5, so that the test requirements of products with different sizes are met. The pedal 7 is stepped on to drive the cylinder 1 to descend and drive the probe 4 to descend, so that the probe contacts a measured piece. The fixed plate 3 descends to the low position, and the trigger switch 6 is closed to perform measurement once.

The beneficial effects are that: compared with the practical traditional Kelvin clamp or Kelvin probe, the utility model has the advantages that:

1) The utility model avoids the actions of continuously pinching the clamp and continuously pressing by an operator, reduces the operation intensity of the operator and improves the efficiency.

2) Because the spring is in a compressed state, a certain pressure is applied to the electrode, so that the probe is tightly contacted with the electrode. And the measurement error and the sparking phenomenon caused by poor contact are avoided.

3) The contact force is the elasticity of the spring, so that the measurement result cannot be changed due to the operation of different personnel.

4) The positioning plate is replaceable, and the position of the probe is adjustable, so that the product testing device supports product testing of various sizes.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model.

Detailed Description

The reference numerals of the various parts in the drawings illustrate: 1. cylinder, 2, support, 3, (probe) fixed plate, 4, spring probe, 5, (probe) locating plate, 6, trigger switch, 7, footboard.

Taking the forward pressure drop of the test SKRS products 300-100 as an example:

A. connecting the clamp to the tester;

B. Selecting a corresponding positioning plate 5 and installing the positioning plate in place;

C. the position of the spring probe 4 is adjusted on the probe fixing plate 3, so that the distance between the spring probes 4 is adjusted, and the probes can be correctly pressed on the product point;

D. The pedal is stepped down, the product is placed on the positioning plate, and the product is positioned according to the positioning point;

E. the pedal is released, the probe falls down, and one measurement is automatically completed.

Claims (3)

1. The pneumatic Kelvin test fixture is characterized by comprising an operation table, wherein the operation table is connected to a Kelvin tester through a wire and comprises a bracket, a fixed plate, a positioning plate, a spring probe, a cylinder and a tester trigger switch; the spring probe is fixed on the telescopic arm of the air cylinder, and is lifted and lowered by the telescopic arm of the air cylinder, and the spring probe contacts and disconnects a device to be tested, so that Kelvin connection and disconnection are realized, and meanwhile, a testing instrument is triggered, so that measurement is realized; the positioning plate is arranged on the operation table and used for fixing the device to be tested; the fixed plate of the spring probe is fixed with the telescopic arm of the air cylinder, the spring probe is arranged on the fixed plate of the spring probe, and the interval between the spring probes can be adjusted, so that the spring probe can be correctly pressed on a contact of a device to be tested; the device to be tested is placed on a positioning plate.

2. The pneumatic kelvin test fixture according to claim 1, wherein grooves are provided on the probe fixing plate to fix the probes at different positions; the position of the probe on the fixed plate is manually adjusted, so that the test requirements of products with different sizes are met.

3. The pneumatic kelvin test fixture according to claim 1, wherein a foot pedal is provided for controlling the operation of the drive cylinder.