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Calibrated Mask for X Ray Radiographic Measurements

IP.com Disclosure Number: IPCOM000083545D
Original Publication Date: 1975-Jun-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Bovee, JR: AUTHOR

Abstract

This is a device to determine the dimensions and locations of voids within lead-tin solder contacts of semiconductor chips or lead-tin fingers on ceramic substrates. A calibrated mask containing predetermined hole dimensions is used in conjunction with X-ray equipment, to determine the location and dimension of voids caused by improper processing.

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Calibrated Mask for X Ray Radiographic Measurements

This is a device to determine the dimensions and locations of voids within lead-tin solder contacts of semiconductor chips or lead-tin fingers on ceramic substrates. A calibrated mask containing predetermined hole dimensions is used in conjunction with X-ray equipment, to determine the location and dimension of voids caused by improper processing.

As shown in the figures, the mask is a composite of a brass plate having holes of uniform width drilled therethrough and a lead-tin strip having holes of the same dimension but varying in depth.

The mask is placed adjacent the sample specimen; and X-rays are passed through both onto a photographic film. A comparison is then made of the radiogram of the calibrated metal mask and the void-containing sample. The varying density of the grey shades of the film determines the depth of the voids.

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