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Detection method for stucked pins of electrical test fixture for High-dencity circuits

IP.com Disclosure Number: IPCOM000016022D
Original Publication Date: 2002-Sep-22
Included in the Prior Art Database: 2003-Jun-21
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Abstract

Main idea

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  Detection method for stucked pins of electrical test fixture for High-dencity circuits

Main idea

This is the idea to detect the jammed pin probes in the electrical test fixture for high density printed circuit board (PCB) . Those jammed probes cause the mechanical pin probe damage on the PCB. In this idea those probes are detected by applying insulation film on the conductive boards.

Probe damage mechanism and current method

In the electrical test for PCB, that is OPEN / SHORT test, the dedicated fixtures are used to contact all pads on the board. A lot of pin probes are used in those fixtures. Basically those pin probes have spring mechanism shown as Fig 1.

Those probes are sometimes jammed because of the spring life, irregular force by accident, contamination, etc. This jamming cause the damage on the board, this means that those damaged boards may be scraped. Since the test is done in automatic tester, once the damage happened, the amount of the damage will be huge.

To detect those jamming the visual inspection is applied periodically. But this inspection isn't so efficient method to prevent those damages.

TO TESTER

DAMAGE!!

SpringCylinder

Probe

PCB

The method proposed in this disclosure

In this idea, the insulation film is used. The film is applied on the conductive board, such as copper plated board. And this board is connected to the tester as well as the pin probes in the fixture. When the jamming was happened, this probe connect to the board by braking th...