Test plate for ceramic surface mount devices and other electronic components

#1. Technical Field

#This invention relates generally to the batch processing of miniature electronic circuit components, including passive, two-terminal, ceramic capacitors, resistors, inductors, and the like. More particularly, it concerns a test plate for holding such components or other type of device under test (DUT) as part of the batch processing for purposes of parametric testing.

#2. Description of Related Art

#FIG. 1 of the drawings is a top plan view of a multilayer test plate constructed according to the invention;

#FIG. 2 is a reduced-in-size exploded view of the multilayer test plate showing the first and second nonconductive layers and the first and second conductive layers;

#FIG. 3 is a top plan view of just the first nonconductive layer of the test plate;

#FIGS. 1-7 of the drawings show various aspects of a multilayer test plate 10 constructed according to the invention. Generally, a test plate constructed according to the invention includes at least two layers such that at least one layer is conductive and at least one layer is nonconductive. That way, the conductive layer can be used as a guard layer held at a desired guard potential for testing purposes. A test plate constructed according to the invention may have more than two layers and more than one conductive guard layer. The illustrate test plate 10 includes four layers of which two are conductive and two are nonconductive.

#The layers of the test plate 10 combine to define an array of DUT-receiving holes 10A, just one such DUT-receiving hole 10A being identified in FIG. 1 for illustrative convenience. The illustrated test plate 10 includes four hundred, circularly shaped, DUT-receiving holes 10A arranged in four radially spaced apart, concentric rings of one hundred, circumferentially spaced apart holes each. Of course, the number, shape, and pattern of the holes can vary without departing from the inventive concepts disclosed.

#With a batch of DUTs in the DUT-receiving holes 10A, the test plate 10 serves the function of holding the batch of DUTs for movement past a contactor assembly 10B on a component testing system 10C depicted diagrammatically in FIG. 9. The component testing system 10C typically includes alignment pins (not shown) that seat in a pair of alignment holes 10D and 10E extending through the test plate 10 (FIG. 1) in order to help align the test plate 10 with supporting structure on the component testing system. Related details are described in the U.S. Pat. Nos. 6,204,464; 6,294,747; 6,194,679; 6,069,480; 4,395,184; and 4,669,416 mentioned previously. In addition, U.S. patent application Ser. No. 10/097,464 provides details of the contactor assembly 10B and its operation in the testing system 10C, and that patent application is incorporated herein by reference for the details provided.