US 5,631,856 A · Test sequence optimization process for a circuit tester

Abstract

The sequential order of movements of a number of probes within a circuit test fixture is optimized through the use of an algorithm which sequentially orders test configurations provided in an input list. Each test configuration corresponds to the locations of probes within the fixture as a particular test is performed. In a first pass of the algorithm, for each test configuration, every other test configuration is considered as a next move candidate for which a weighted distance is calculated from the test configuration. Weighting factors reflect the degree of difficulty in moving one direction instead of another. A need to move one probe before another or to move in one direction before another, in order to prevent a collision within the test fixture, is also considered. A predetermined number of next move candidates having the lowest weighted distances are placed in an intermediate list for the test configuration. In a second pass of the algorithm, test configurations are linked, one to another, to form a list reflecting a preferred order of probe movement. In the process of linking with a test configuration, the available next move candidate having the shortest weighted distance is chosen from the intermediate list of the test configuration. If no available next move candidates remain in the intermediate list, the process returns to the first pass of the algorithm to get more next move candidates. Additionally, the algorithm is used to sequentially order individual points for a test fixture having only a single probe.

Claims24

Dependent claims

A method for optimizing a sequence of test configurations within a circuit tester having structures movable between various of said test configurations, wherein said method comprises the steps of:

reading an input list of said test configurations;
for each test configuration within said input list, establishing each other of said test configurations as a next move candidate, calculating a weighted distance from said test configuration to said next move candidate, wherein said weighted distance reflects a degree of difficulty in movement of said structures within said circuit tester from said test configuration to said next move candidate, and storing an intermediate list having a maximum of a predetermined number of next move candidates, wherein said intermediate list includes said next move candidates with lowest weighted distances from said test configuration, and wherein said predetermined number is less than a total number of test configurations in said input list;
and
linking said test configurations into a chain, in a preferred order beginning with an initial said test configuration, wherein each said test configuration following said initial test configuration is chosen from available next move candidates within said intermediate list of a test configuration at an end of said chain, wherein when a said next move candidate is linked, said next move candidate is removed from said available next move candidates, and wherein, until all said test configurations are linked, when said next move candidates have been exhausted from said intermediate list of said test configuration at said end of said chain, an additional said next move candidate is added to said intermediate list of said test configuration at said end of said chain.

1 more element

Apparatus for testing electrical circuits on a substrate, wherein said apparatus comprises:

clamping means holding said substrate in a fixed location;
a probe movable from a location defined by a first test configuration to a location defined by another test configuration;
data processing means including data reading means;
a first input list of test configurations, read by said data reading means, wherein each test configuration within said first input list describes a location of said probe during a test procedure within said apparatus;
a program executing on said data processing means, wherein said program includes a first pass subroutine reading said first input list, and, for each said test configuration, establishing each other of said test configurations as a next move candidate, calculating a weighted distance from said test configuration to said next move candidate, storing an intermediate list having a maximum predetermined number of next move candidates, said predetermined number being less than a total number of test configurations in said input list, with said intermediate list including said next move candidates with lowest weighted distances from said test configuration, wherein said program additionally includes a second pass subroutine linking said test configurations into a chain, in a preferred order beginning with an initial said test configuration, with each test configuration being chosen from available next move candidates within said intermediate list of a test configuration at an end of said chain, with said next move candidates being removed from availability as they are linked to said chain, and with said second pass subroutine calling said first pass subroutine to refill said intermediate list when next move candidates have been exhausted from said intermediate list of said test configuration at said end of said chain;
and
means for moving said probe between positions indicated by said test configurations in said preferred order.

4 more elements

Dependencies are inferred from the claim text.

Test sequence optimization process for a circuit tester

Life of this patent

Test sequence optimization process for a circuit tester

Life of this patent

Abstract

Claims24