Influence of Dielectric Materials on ATE Test Fixtures for High-Speed Digital Applications

There are ever increasing challenges when developing test fixtures for high-speed applications using automated test equipment (ATE). This is due to the many variables and considerations that must go into developing characterization test fixtures for I/O cells in the 5 to 10 Gbps range. The purpose of these fixtures is to provide the best possible signal integrity of multi-gigabit data signals between the ATE and the device under test (DUT). One of the variables and considerations that needs to be controlled is the correct choice of dielectric material. Although there is a significant amount of work on dielectric loss for microwave applications, high-speed digital applications have different requirements given the broad frequency bandwidth of digital data patterns, as well as the high density of the I/O interconnects. Modern integrated circuits might have hundreds of differential high speed I/O cells requiring complex multilayer printed circuit boards (PCB) composed of different dielectric materials to be utilized for the test fixtures.