CIRCUITS, METHODS, AND COMPUTER PROGRAMS TO DETECT MECHANICAL STRESS AND TO MONITOR A SYSTEM

• US 20160273991A1
• Filed: 04/15/2016
• Published: 09/22/2016
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Hammerschmidt, Dirk, Rasbornig, Friedrich, Strasser, Michael
• Granted Patent: US 10,352,812 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01L 1/18 using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
• CPC Class Codes: G01L 25/00 Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency
• CPC Class Codes: G01M 5/0083 by measuring variation of impedance, e.g. resistance, capacitance, induction
• CPC Class Codes: G01R 31/2856 Internal circuit aspects, e.g. built-in test features; Test chips; Measuring material aspects, e.g. electro migration [EM]
• CPC Class Codes: G01R 31/2881 related to environmental aspects other than temperature, e.g. humidity or vibrations
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633

Abstract

Embodiments provide a circuit, a method, and a computer program configured to detect mechanical stress and a circuit, a method, and a computer program configured to monitor safety of a system. The detection circuit is configured to monitor a mechanical stress level of a semiconductor circuit. The detection circuit comprises a stress monitor module configured to monitor a signal comprising mechanical stress level information of the semiconductor circuit, a reference module to generate a reference signal, and a calibration module configured to modify at least one of the stress signal or the reference signal based on calibration information for the semiconductor circuit to obtain a at least one modified signal. The detection circuit further comprises an activation signal generator configured to generate an activation signal comprising activation information related to the mechanical stress level of the semiconductor circuit depending on a relation between the modified signal, and the stress signal or the reference signal.

Claims

1. A detection circuit configured to monitor a mechanical stress level of a semiconductor circuit, the detection circuit comprising:

a stress monitor module configured to monitor a stress signal comprising mechanical stress level information of the semiconductor circuit;

a reference module configured to provide a reference signal;

a calibration module configured to modify at least one of the stress signal or the reference signal based on calibration information for the semiconductor circuit to obtain at least one modified signal; and

an activation signal generator configured to generate an activation signal comprising activation information related to the mechanical stress level of the semiconductor circuit depending on a relation between the modified signal, and the stress signal or the reference signal.

2. The detection circuit of claim 1, wherein the calibration module is configured to base the calibration information at least partly on information determined in a calibration of the semiconductor circuit after packaging or during an end of line test.

3. The detection circuit of claim 1, wherein the calibration module is configured to base the calibration information at least partly on information determined during an end of line test, and wherein the calibration information determined during the end of line test contains at least one of an offset correction factor or a sensitivity correction factor.

4. The detection circuit of claim 1, wherein the reference module is configured to provide a threshold as reference signal, the threshold indicating a mechanical stress level threshold for the semiconductor circuit.

5. The detection circuit of claim 1, wherein the calibration module is configured to base the calibration information at least partly on information read from a non-volatile memory.

6. The detection circuit of claim 1, wherein the calibration module is configured to determine the calibration information further based on temperature information.

7. The detection circuit of claim 1, wherein the activation signal generator is configured to generate the activation signal further based on the calibration information and/or on temperature information.

8. The detection circuit of claim 1, wherein the activation signal generator is configured to base the calibration information at least partly on information read from a non-volatile memory.

9. The detection circuit of claim 1, wherein the semiconductor circuit is configured to determine a sensor signal, and wherein the activation signal generator is configured to base the activation signal on at least one of the sensor signal, a compensated sensor signal or the modified signal.

10. The detection circuit of claim 1, wherein the calibration module is configured to modify the sensor signal based on the mechanical stress level information to obtain the compensated sensor signal.

11. The detection circuit of claim 1, wherein the activation signal generator is configured to base the activation signal on the stress signal comprising the mechanical stress level information and/or the calibration information.

12. The detection circuit of claim 1, wherein the stress monitor module comprises a stress sensor configured to measure a mechanical stress of the semiconductor circuit and to provide the signal comprising the mechanical stress level information.

13. The detection circuit of claim 11, further comprising a control module, the control module comprising the activation signal generator, wherein the control module is configured to obtain a sensor signal from another sensor, wherein the control module is configured to use the mechanical stress level information to improve a measurement accuracy of the sensor signal and to generate the activation signal using the activation signal generator.

14. The detection circuit of claim 13, wherein the control module further comprises the calibration module, and wherein the control module is configured to modify the sensor signal using the at least one modification signal, wherein the modification signal is based on the calibration information and based on the mechanical stress level information, and wherein the control module is configured to generate the activation signal if the at least one modification signal exceeds a threshold.

15. The detection circuit of claim 12, wherein the calibration information comprises at least one of a stress dependent offset for addition to the sensor signal from the other sensor or a stress dependent gain factor for multiplication with the sensor signal from the other sensor.

16. The detection circuit of claim 1, wherein the activation signal generated by the activation signal generator is configured to cause an activation of a safety measure.

17. The detection circuit of claim 1, wherein the activation signal generator is further configured to compare signals of two or more sensors, the signals comprising mechanical stress level information of two or more semiconductor circuits, and to generate the activation signal if a mechanical stress level indicated by the two or more signals deviates by more than a threshold.

18. A safety monitoring circuit being configured to monitor a system, comprising:

the detection circuit of claim 1; and

a control module configured to receive the activation signal from the activation signal generator and to apply a safety measure to the system when the activation signal is received.

19. A safety monitoring circuit configured to monitor a system, comprising:

a stress monitor module configured to monitor a sensor signal and to determine an estimated deviation of a sensor signal which is evoked by a mechanical stress level of a semiconductor circuit;

an activation signal generator configured to generate an activation signal comprising activation information related to the mechanical stress level of the semiconductor circuit if a predefined relation between the sensor signal and the estimated deviation of the sensor signal is fulfilled.

20. The safety monitoring circuit of claim 19, wherein the stress monitoring module is further configured to compensate deviations caused in the sensor signal by a mechanical stress level of the semiconductor circuit, and wherein the activation signal generator is configured to generate the activation signal if the estimated deviation exceeds a threshold.

22. The method of claim 20, further comprising reading the calibration information from a non-volatile memory.

21. A method for monitoring a mechanical stress level of a semiconductor circuit a sensor signal, comprising:

monitoring a stress signal comprising mechanical stress level information of the semiconductor circuit;

providing a reference signal;

modifying at least one of the stress signal or the reference signal based on calibration information for the semiconductor circuit to obtain a modified signal; and

generating an activation signal comprising activation information related to the mechanical stress level of the semiconductor circuit depending on a relation between the modified signal, and the stress signal or the reference signal.