The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1991
Filed:
Oct. 23, 1990
Tetsuo Tada, Hyogo, JP;
Ryouichi Takagi, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A probing card for wafer testing has a plurality of probes arranged so as to correspond to and come in contact with a plurality of bonding pads of semiconductor devices fabricated on a semiconductor wafer. The probing card comprises a base plate, contact fingers and wiring sections. The base plate is formed of photosensitive glass. The base plate defines through holes extending from one of its main surfaces to the other. The contact fingers are formed as columnar elements filling the through holes and having a cross-sectional area decreasing from opposite ends to an intermediate position thereof. Each contact finger has one end thereof projecting from one of the main surfaces of the base plate. This projecting end of each contact finger at least defines a substantially planar end face. The wiring sections comprise conductive layers formed in a predetermined pattern on the other main surface of the base plate and connected respectively to the other ends of the contact fingers. The through holes are formed in the photosensitive glass base plate by photolithography. The contact fingers may be positioned with high precision relative to a plurality of bonding pads. A stable contact is secured between the bonding pads and contact fingers.