Gray scale etching for thin flexible interposer

US6156484A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Ernest Bassous · The Bronx, US
• Gobinda Das · Hopewell Junction, US
• Frank D. Egitto · Binghamton, US
• Natalie B. Feilchenfeld · Jericho, US
• Elizabeth Foster · Friendsville, US
• Stephen Joseph Fuerniss · Sayre, US
• James Steven Kamperman · Endicott, US
• Donald Joseph Mikalsen · Carmel, US
• Michael R. Scheuermann · Katonah, US
• David B. Stone · Williamsport, US

Key dates

• Filing date: Feb 11, 1998
• Grant date: Dec 5, 2000
• Expiry date: Feb 11, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R3/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Disclosed is a sculpted probe pad and a gray scale etching process for making arrays of such probe pads on a thin flexible interposer for testing the electrical integrity of microelectronic devices at terminal metallurgy. Also used in the etching process is a novel fixture for holding the substrate and a novel mask for 1-step photolithographic exposure. The result of the invention is an array of test probes of preselected uniform topography, which make ohmic contact at all points to be tested simultaneously and nondestructively.