Browse Prior Art Database

Method for Probing Microbumps on a Wafer or Chip

IP.com Disclosure Number: IPCOM000240518D
Publication Date: 2015-Feb-05
Document File: 1 page(s) / 54K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method to use reasonably sized test probe geometries to contact the microbumps at wafer final test (WFT).

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Method for Probing Microbumps on a Wafer or Chip

Wafer bumping is migrating from ~150 um pitch to ~50 um pitch.

This disclosure describes a method to contact the microbumps at wafer final test (WFT).

Using microbump technology and strategies to gang microbumps, both of which are prior art, bumps can be aligned for wafer test optimization. This method uses reasonably sized test probe geometries for microbumps.

Randomly assigning the nets at microbump positions does not work with today's probe geometries. Since organizing bump placement by nets is expected in future microbump products, choosing the appropriate geometric locations for the microbumps and a hemispherical probe tip at WFT can optimize both for the use of reasonably sized probe geometries at wafer test. Probe geometries of reasonable size, such as diameter, are needed for other parts of the probe structure, such as the length of the probe supporting the tip. A WFT probe a diameter that is too small

cannot be prepared with sufficient length to be useful. Probes of reasonable diameter do not work with randomly assigned nets for microbumps.

Figure: Microbump probing for wafer final test


Enlarged Scale: Micronbumps at ~ 50 um pitch with standard size probe

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