The Infinity RF wafer probe series works with fine-pitch aluminum pads, creating low and stable contact resistance. Densification and nanodevice trends drove the development of the probes at pitches down to 50µm. The series is said to accurately probe smaller pads, including mixed-signal MOS devices. The wave-guide series measures to 220 GHz, in a range of 50- to 150-µm pitch. Bias tee options are available. The wafer probes combine proprietary thin-film with co-axial technology, and can make contact on pads down to 25 × 25 µm. Microstrip transmission lines restrict fringing fields to reduce couplings to nearby devices or probe tips. This reportedly enhances accuracy with an RF connection to aluminum pads. Force delivery with the series entails a small horizontal motion — a scrub — that breaks through to aluminum oxide for contact, leaving minimal pad damage. The probes suit devices used in automotive collision avoidance systems, satellite telecommunications, radio astronomy, spectroscopy, and medical imaging. Cascade Microtech, Inc., Beaverton, OR, www.cascademicrotech.com.