Importance

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Abstract

A vacuum test fixture for the in-circuit and functional testing of loaded printed circuit boards is disclosed. Key components of the test fixture are made from inexpensive state-of-the-art structural plastics under new molding techniques. As a result, a much lighter, more convenient, more compact and considerably less expensive vacuum test fixture is realized without loss of dimensional precision and stability in the most vital components of the fixture. The fixture is constructed to be snapped together and retained by a unitary structurally sound molded trim frame which is lightweight and durable and can be manipulated without tools. An effective seal is established between a top plate and an insert retainer for a lower plate of the fixture by an adhesive-free from fitting neoprene gasket which embraces the margin of the top plate. To create an air seal between the PCB and vacuum test fixture, a closed cell double skin neoprene pad is adhesively attached to the top plate of the fixture. Manually operated thumb screws are used to secure the bottom plate of the fixture removably in the molded insert retainer. Precision tooling pins hold the top and bottom plates horizontally aligned so that the test probes carried by the bottom plate accurately engage the PCB electrical components and experience only linear vertical motion during the test operation.

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First Claim