Multi-temperature programming for accelerometer

• US 20070204672A1
• Filed: 03/01/2006
• Published: 09/06/2007
• Est. Priority Date: 03/01/2006
• Status: Active Grant

• Current Assignee: Memsic Semiconductor (Wuxi) Co., Ltd. (MZ Investment Holdings Ltd.)
• Original Assignee: Memsic Incorporated (MZ Investment Holdings Ltd.)
• Inventors: Liu, Haidong, Huang, Feiming
• Granted Patent: US 7,461,535 B2
• Time in Patent Office: Days
• US Class Current: 73/1.880
• CPC Class Codes: G01P 15/008 by using thermal pick-up
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A system and method for testing and calibrating integrated sensor devices that improves the manufacturing test throughput of the devices. The system includes a tester, a temperature controller, and at least one probe station including a thermal chuck. The chuck can be heated to specified temperatures to achieve variable heating of a wafer, PCB, or pallet disposed thereon. The temperature controller adjusts the temperature of the chuck to a first specified level. The tester performs at least one first measurement of the output offset of each integrated sensor embodied as a die on the wafer, or as a device on the PCB or pallet. Next, the temperature controller adjusts the temperature of the chuck to a second specified level, and the tester performs at least one second measurement of the output offset of each integrated sensor at the second temperature level. The offset temperature coefficient (OTC) of each sensor is calculated based upon the output offset measurements performed at the first and second temperature levels, and optimal settings for calibrating the respective sensors are determined based upon the calculated OTC values. After the temperature of the chuck is brought back down to the first specified level, the tester programs the output offset calibration settings into each sensor.

Claims

1. A method of calibrating at least one sensor having at least one associated output parameter that is temperature dependent, comprising the steps of:

disposing said at least one sensor on a thermal chuck;

adjusting a temperature of said thermal chuck to at least one first specified level, thereby setting a temperature of said at least one sensor to approximately the first specified level;

taking a first measurement of said output parameter associated with said at least one sensor while the temperature of said at least one sensor is set to approximately the first specified level;

adjusting the temperature of said thermal chuck to at least one second specified level, thereby setting the temperature of said at least one sensor to approximately the second specified level;

taking a second measurement of said output parameter associated with said at least one sensor while the temperature of said at least one sensor is set to approximately the second specified level;

calculating a temperature coefficient of said output parameter based upon the first and second measurements of said parameter performed at approximately the first and second temperature levels, respectively;

determining at least one calibration value based upon the temperature coefficient of said output parameter; and

employing said at least one calibration value to compensate and calibrate said output parameter associated with said at least one sensor.

2. The method of claim 1 wherein said at least one sensor comprises at least one programmable electronic circuit, and further including the step of programming said at least one programmable electronic circuit within said at least one sensor to maintain at least one calibration setting according to said at least one calibration value, thereby compensating and calibrating said output parameter associated with said at least one sensor.

3. The method of claim 2 further including the step of adjusting the temperature of said thermal chuck to the first specified level before performing said programming step.

4. The method of claim 1 wherein said thermal chuck is disposed within a process chamber, and further including the step of adjusting a temperature of said process chamber to at least one specified level.

5. The method of claim 1 wherein said at least one sensor is disposed on at least one die formed on a semiconductor wafer, and wherein said employing step includes the step of employing said at least one calibration value to perform wafer level compensation and calibration of said output parameter associated with said at least one sensor.

6. The method of claim 5 wherein said step of taking the first measurement of said output parameter associated with said at least one sensor includes the step of taking the first measurement of said output parameter using a wafer prober, and wherein said step of taking the second measurement of said output parameter associated with said at least one sensor includes the step of taking the second measurement of said output parameter using said wafer prober.

7. The method of claim 1 wherein said at least one sensor is incorporated within at least one device disposed on one of a printed circuit board and a pallet, and wherein said employing step includes the step of employing said at least one calibration value to perform one of printed circuit board level and pallet level compensation and calibration of said output parameter associated with said at least one sensor.

8. The method of claim 7 wherein said step of taking the first measurement of said output parameter associated with said at least one sensor includes the step of taking the first measurement of said output parameter using a device prober, and wherein said step of taking the second measurement of said output parameter associated with said at least one sensor includes the step of taking the second measurement of said output parameter using said device prober.

9. The method of claim 1 wherein said at least one sensor comprises at least one integrated convective accelerometer, wherein said output parameter associated with said at least one sensor is an output offset associated with said at least one integrated convective accelerometer, and wherein said calculating step includes the step of calculating at least one offset temperature coefficient (OTC) of said at least one integrated convective accelerometer.

10. A method of calibrating at least one acceleration sensor having at least one associated sensitivity parameter that is temperature dependent, comprising the steps of:

disposing said at least one acceleration sensor on a support platform within at least one oven chamber;

a first temperature adjusting step including the step of adjusting a temperature of said at least one oven chamber to at least one first specified level, thereby setting a temperature of said at least one acceleration sensor to approximately the first specified level;

a first acceleration applying step including the step of applying a first level of acceleration to said at least one acceleration sensor while the temperature of said at least one acceleration sensor is set to approximately the first specified level;

a first measurement taking step including the step of taking a first measurement of an output of said at least one acceleration sensor while the first level of acceleration is being applied to said at least one acceleration sensor;

a second temperature adjusting step including the step of adjusting the temperature of said at least one oven chamber to at least one second specified level, thereby setting the temperature of said at least one acceleration sensor to approximately the second specified level;

a second acceleration applying step including the step of applying a second level of acceleration to said at least one acceleration sensor while the temperature of said at least one acceleration sensor is set to approximately the second specified level;

a second measurement taking step including the step taking a second measurement of the output of said at least one acceleration sensor while the second level of acceleration is being applied to said at least one acceleration sensor;

calculating at least one value of said sensitivity parameter associated with said at least one acceleration sensor based upon the first and second measurements of the output of said at least one acceleration sensor performed at approximately the first and second temperature levels, respectively;

determining at least one calibration value based upon the value of said sensitivity parameter associated with said at least one acceleration sensor; and

employing said at least one calibration value to compensate and calibrate said sensitivity parameter associated with said at least one acceleration sensor.

11. The method of claim 10 wherein said at least one acceleration sensor comprises at least one programmable electronic circuit, and further including the step of programming said at least one programmable electronic circuit within said at least one acceleration sensor to maintain at least one calibration setting according to said at least one calibration value, thereby compensating and calibrating said sensitivity parameter associated with said at least one acceleration sensor.

12. The method of claim 11 further including the step of adjusting the temperature of said at least one oven chamber to the first specified level before performing said programming step.

13. The method of claim 10 wherein said at least one oven chamber comprises a first oven chamber and a second oven chamber, wherein said disposing step includes the step of disposing said at least one acceleration sensor on a first support platform within said first oven chamber, and wherein said first temperature adjusting step, said first acceleration applying step, and said first measurement taking step are each performed while said at least one acceleration sensor is disposed within said first oven chamber.

14. The method of claim 13 further including the step of disposing said at least one acceleration sensor on a second support platform within said second oven chamber, and wherein said second temperature adjusting step, said second acceleration applying step, and said second measurement taking step are each performed while said at least one acceleration sensor is disposed within said second oven chamber.

15. The method of claim 14 further including the step of transferring said at least one acceleration sensor from the first support platform within said first oven chamber to the second support platform within said second oven chamber.

16. The method of claim 10 wherein each of said first and second acceleration applying steps includes the step of rotating said support platform having said at least one acceleration sensor disposed thereon.

17. The method of claim 10 wherein said at least one acceleration sensor is disposed on at least one die formed on a semiconductor wafer, and wherein said employing step includes the step of employing said at least one calibration value to perform wafer level compensation and calibration of said sensitivity parameter associated with said at least one acceleration sensor.

18. The method of claim 17 wherein each of said first and second measurement taking steps includes the step of taking a measurement of the output of said at least one acceleration sensor using a wafer prober.

19. The method of claim 10 wherein said at least one acceleration sensor is incorporated within at least one device disposed on one of a printed circuit board and a pallet, and wherein said employing step includes the step of employing said at least one calibration value to perform one of printed circuit board level and pallet level compensation and calibration of said sensitivity parameter associated with said at least one acceleration sensor.

20. The method of claim 19 wherein each of said first and second measurement taking steps includes the step of taking a measurement of the output of said at least one acceleration sensor using a device prober.