Abstract:
Standard connections from the probe head to the PCB for vertical type probe cards in wafer test are individual separate
wires in space transformers (STs), traditionally used for device pitches 80 µm and above for quick turn inexpensive solutions compared
to multilayer ceramic substrates. There are inherent signal integrity issues using separate wires in controlling impedance, bandwidth,
and cross-talk of STs and probe cards. A method of wiring that includes parallel pairs and twisted pairs is proposed and electrical
characterization was performed to establish predictive specifications on the test cards.
