Tester for pressure sensors

• US 6,688,156 B2
• Filed: 01/04/2001
• Issued: 02/10/2004
• Est. Priority Date: 01/04/2000
• Status: Expired due to Fees

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Karl Suss Dresden GMBH
• Inventors: Teich, Michael, Runge, Dietmar, Dietrich, Claus, Hirschfeld, Botho, Schneidewind, Stefan
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US09/754,711
• Publication Number:
  US 20020152794A1
• Time in Patent Office: 1,132 Days
• Field of Search: 73/15.7, 73/15.8, 73/16.8, 737/06, 737/15--56, 73/16.3, 73/16.4, 73/17.1
• US Class Current: 73/1.68
• CPC Class Codes: G01L 27/007 Malfunction diagnosis, i.e. diagnosing a sensor defect

Abstract

The invention relates to a tester for pressure sensors in the wafer compound or isolated pressure sensors having a recess for the pressure sensors as well as means for electrical contacting of the electrical connections of at least one of the pressure sensors. The invention is intended to make it possible to test pressure sensors still in a wafer compound for their function. According to the invention, a pressure head is provided which has an interior space open on one side, the open face of which is capable of being mounted on the pressure sensor in such a way that the interior space is tightly sealed by the latter. In this way a static or dynamic pressure of specified amount and duration can be exerted on the sensor element at least so that the sensor element is moved out of its resting position. At the same time, the electrical connections of the selected pressure sensor are connected with an electrical evaluation unit.

Claims

1. A tester for pressure sensors, either in a wafer structure or isolated, comprising:

a recess for receiving the pressure sensors;

means for electrically connecting at least one of the pressure sensors to an evaluation unit;

means for exerting one of a static and a dynamic pressure of a specified amount and duration on a sensor element of the at least one selected pressure sensor such that the sensor element is displaced from a resting position.

2. The tester according to claim 1, wherein the means is designed as a pressure chamber for the production of a static pressure, in which the tester is at least partially arranged with the pressure sensors located in the recess.

3. The tester according to claim 2, wherein at least the selected pressure sensors are arranged within the pressure chamber.

4. The tester according to claim 1, wherein a pressure head is provided which includes an interior space having an open face on one side, the open face is capable of being mounted on the pressure sensor such that the interior space is tightly sealed by the latter.

5. The tester according to claim 4, wherein the pressure head is connected with a means for production of a specified pressure in the interior space of the pressure head.

6. The tester according to claim 4, further comprising a pressure-measuring probe arranged in the interior space of the pressure head.

7. The tester according to claim 4, wherein means for electrical contacting of the electrical connections of the pressure sensor is assigned to the pressure head.

8. The tester according to claim 7, wherein the means for electrical contacting comprise needle probes for electrical contacting of the electrical connections of the pressure sensor, the needle probes being arranged in the interior space of the pressure head.

9. The tester according to claim 1, wherein the means for electrical contacting of the electrical connections of the pressure sensor and the pressure head are positionable independently of one another with respect to the selected pressure sensor.

10. The tester according to claim 4, wherein the pressure head is capable of being mounted on the pressure sensor with a specified compressive force.

11. The tester according to claim 10, wherein the compressive force is produced by one of a weight and an elastic force.

12. The tester according to claim 4, wherein the open face is designed as a sealing face.

13. The tester according to claim 4, wherein a sealing element is inserted in the open face.

14. The tester according to claim 4, wherein a vacuum groove that is connected with a means for production of a negative pressure is incorporated in the open face.

15. The tester according to claim 1, wherein a thermochuck is provided for the accommodation of pressure sensors located in the wafer structure, in that the wafer is arranged face down on the thermochuck such that sensor intakes of the pressure sensors are arranged in a grid and rest directly on the thermochuck, the thermochuck being provided with a grid of holes substantially aligned with the grid of the sensor intakes.

16. The tester according to claim 15, wherein the holes are selectively individually connectable with a means for production with one of a positive pressure or with a means for production of a negative pressure.

17. The tester according to claim 15, wherein the holes are capable of being acted on by pressure, groupwise or linewise, and the holes adjacent to the group or line are capable of being acted on by negative pressure, groupwise or linewise.

18. The tester according to claim 1, wherein a pressure head for production of a flow in the direction of a sensor intake of the pressure sensors for production of a stagnation pressure is provided.

19. The tester according to claim 18, wherein the pressure head is provided with a vertically aligned tubule having a lower opening ending at a specified distance above the pressure sensor and having a second end connected with a pressure-measuring chamber and a test pressure supply line.

20. The tester according to claim 17, wherein a plurality of needle probes are provided at the tubule proximate its lower opening, for electrical contacting of the electrical connections of the pressure sensor.

21. The tester according to claim 20, wherein the needle probes are capable of being mounted on the electrical connections of the pressure sensor in the elastic region.

22. The tester according to claim 18, wherein a test card is provided for electrical contacting of each selected pressure sensor, and in that a pressure head is positionable on the selected pressure sensor independently of the test card.

23. The tester according to claim 18 wherein a test card for electrical contacting of each selected pressure sensor is provided, and in that a pressure head is positionable on the selected pressure sensor jointly with the test card.

24. The tester according to claim 4, wherein the pressure head is fastened to an X-Y-Z cross table.