Module attachment for printed circuit board test fixtures

Abstract

A module attachment for testing a linear high density array of test sites on a printed circuit board having such circuit test sites where an integrated circuit chip (IC) is to be mounted. Present IC's may have wire lead spacings as close as 0.010 inch with integrated chip development utilizing even more compact and close center pad spacing, such as 0.004 inch. This spacing is too close to use even the thinnest of spring contact probes. The module carries an array of densely packed thin wires embedded in a small matrix block mounted on spaced supports, which may be conventional, large diameter spring contact probes. Electrical connection to the array of wires in the module is done by each wire being connected to a separate wire lead with the wires bundled and routed to a test computer. In its closest wire spacings, the module permits testing of the densest IC's and in wider spacings, provides a low cost alternative to spring contact probes. The mounting interface between the supports and the module is an adjustable bar for precisely positioning the wires with the test sites. Comb structures of selected spacing hold the wires in position and facilitate ease of manufacture. Several embodiments are disclosed including varieties with bottom wire lead connections, side wire lead connections, staggered side lead connections, and special wire tips that can scratch through varnish or other contaminants on the test site.