Minimum voltage and maximum performance mapping using laser-assisted techniques

Patent metadata

Field	Value
Publication number	US-2016116531-A1
Application number	US-201414525539-A
Country	US
Kind code	A1
Filing date	Oct 28, 2014
Priority date	Oct 28, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A method and apparatus for mapping an electronic device. The electronic device is loaded into a test fixture, which may be an automated test equipment (ATE). A laser beam is stepped across locations of interest. At each location of interest a minimum voltage and/or maximum frequency are computed. A contour map of the changes in minimum voltage and maximum frequency across a field of view of the electronic device is generated. Additional embodiments provide signaling a laser scan module during the rising edge of a synchronization pulse to indicate that minimum voltage (Vmin) and maximum frequency (Fmax) specification search data is provided to a laser voltage probe. A Vmin/Fmax module compares the specification search data with the data read from the laser voltage probe and computes a parameter shift value. The laser beam is moved to another location when the falling edge of the synchronization pulse occurs.

First claim

What is claimed is:

1 . A method of mapping an electronic device, comprising:
loading an electronic device into a test fixture; stepping a laser beam across locations of interest on the electronic device; computing a minimum voltage at each location of interest; computing a maximum frequency at each location of interest; and generating a contour map of changes in minimum voltage and maximum frequency across a field of view of the electronic device.

2 . The method of claim 1 , wherein the test fixture is an automated test fixture.

3 . The method of claim 1 , wherein the locations of interest on the electronic device are failing cells.

4 . The method of claim 3 , wherein the failing cells are determined by tests performed by the automated test equipment.

5 . The method of claim 1 , wherein stepping a laser beam across locations of interest on the electronic device further comprises:
signaling a laser scan module during a rising edge of a synchronization pulse that minimum voltage (Vmin) and maximum frequency (Fmax) specification search data is available; sending the Vmin and Fmax data from the test fixture to a laser voltage probe; logging the Vmin and the Fmax specification search data into a Vmin/Fmax mapping module; generating, by the Vmin/Fmax mapping module, a parameter shift value; and moving the laser beam to another position at a falling edge of the synchronization pulse.

6 . The method of claim 5 , wherein the Vmin/Fmax mapping module uses the specification data and initial Vmin and Fmax data measured with no laser stimulation to generate the parameter shift value.

7 . The method of claim 5 , wherein the laser beam is a continuous laser.

8 . The method of claim 1 , wherein stepping a laser beam across locations of interest on the electronic device further comprises:
logging data, by the test fixture, when a laser stimulus signal is at a high value; signaling, by the test fixture, the minimum voltage (Vmin) and maximum frequency (Fmax) specification search data availability, during a rising edge of a synchronization pulse; logging, by the test fixture and a laser scan module, the specification search data and coordinate locations; moving the laser to a next position when a falling edge of the synchronization pulse occurs; stopping logging data, by the test fixture, when the laser stimulus signal is at a low value; sending, by the test fixture, the Vmin and Fmax data to a laser voltage probe; and determining, by a Vmin/Fmax mapping module, a shift in Vmin and Fmax.

9 . The method of claim 8 , wherein the laser beam is a continuous laser.

10 . An apparatus for mapping an electronic device, comprising:
a test fixture; a silicon immersion lens; a laser scan module having a laser source and a laser controller; a minimum voltage (Vmin)/maximum frequency (Fmax) mapping module; and a photo detector.

11 . The apparatus of claim 10 , wherein the Vmin/Fmax mapping module communicates with a laser scan module and test fixture.

12 . The apparatus of claim 11 , wherein the Vmin/Fmax mapping module communicates with a photo detector.

13 . The apparatus of claim 10 , wherein the Vmin/Fmax mapping module incorporates a processor.

14 . An apparatus for mapping an electronic device, comprising:
means for loading an electronic device into a test fixture; means for stepping a laser beam across locations of interest on the electronic device; means for computing a minimum voltage at each location of interest; and means for generating a contour map of changes in minimum voltage and maximum frequency across a field of view of the electronic device.

15 . The apparatus of claim 14 , wherein the means for stepping a laser beam across locations of interest on the electronic device further comprises:
means for signaling a laser scan module during a rising edge of a synchronization pulse that minimum voltage (Vmin) and maximum frequency (Fmax) specification search data is available; means for sending the Vmin and Fmax data from the test fixture to a laser voltage probe; means for logging the Vmin and the Fmax specification search data into a Vmin/Fmax mapping module; means for generating, by the Vmin/Fmax mapping module, a parameter shift value; and means for moving the laser beam to another position at a falling edge of the synchronization pulse.

16 . The apparatus of claim 15 , wherein a means for mapping parameter shift values includes means for storing Vmin and Fmax data measured with no laser stimulation.

17 . The apparatus of claim 15 , wherein the means for stepping a laser beam across locations of interest on the electronic device further comprises:
means for logging data, by the test fixture, when a laser stimulus signal is at a high value; means for signaling, by the test fixture, the minimum voltage (Vmin) and maximum frequency (Fmax) specification search data availability, during a rising edge of a synchronization pulse; means for logging, by the test fixture and a laser scan module, the specification search data and coordinate locations; means for moving the laser to a next position when a falling edge of the synchronization pulse occurs; means for stopping logging data, by the test fixture, when the laser stimulus signal is at a low value; means for sending by the test fixture, the Vmin and Fmax data to a laser voltage probe; and means for determining, by the Vmin/Fmax mapping module, a shift in Vmin and Fmax.

18 . The apparatus of claim 17 , wherein a means for determining, by the Vmin/Fmax mapping module, a shift in Vmin and Fmax includes a means for storing Vmin and Fmax data measured with no laser stimulation.

Assignees

• Qualcomm Inc

Inventors

• Ranganathan Lavakumar
• Villafana Martin
• Endrinal Lesly Zaren Venturina

Classifications

• G01R31/311 Primary

  of integrated circuits {(G01R31/31728 takes precedence)} · CPC title

• G01R31/2834

  Automated test systems [ATE]; using microprocessors or computers (G01R31/317 takes precedence; ATE for detection of defective computer hardware G06F11/2736) · CPC title

• G01R31/2837

  Characterising or performance testing, e.g. of frequency response (transient response G01R27/28) · CPC title