Minimum voltage and maximum performance mapping using laser-assisted techniques

Patent metadata

Field	Value
Publication number	US-9599666-B2
Application number	US-201414525539-A
Country	US
Kind code	B2
Filing date	Oct 28, 2014
Priority date	Oct 28, 2014
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

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;
parking the laser beam at one location of interest at a time 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. 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, 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;

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.

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. 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, 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;

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.

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

Assignees

• Qualcomm Inc

Inventors

• Ranganathan Lavakumar
• Villafana Martin
• Endrinal Lesly Zaren Venturina

Classifications

• G01R31/2837

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

• G01R31/311 Primary

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