Test head design using electrooptic receivers and GaAs pin electronics for a gigahertz production test system

A test head subsystem providing ultrahigh-speed digital signal paths to a device under test is introduced and described. The test head houses liquid-cooled GaAs pin electronics capable of NRZ (non-return-to-zero) data rates up to 1.2 Gb/s. A novel test system receiver scheme utilizing an electrooptic (laser) measurement method is described which captures pin information by connecting the device under test (DUT) to a laser scanned optical sensor assembly having multiple test points. The receiver has a 4.5-GHz bandwidth and can perform ECL (emitter-coupled logic) level functional test with one sampling pulse per vector. Using transmission line theory and advanced interconnection technology, a device environment was design which supports signal bandwidth approaching 5 GHz to connect the GaAs drivers, electrooptic receivers, and the DUT