Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Method of Generating Precise Numerical Control Data on a Distorted Surface

IP.com Disclosure Number: IPCOM000049606D
Original Publication Date: 1982-Jun-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Sanborn, MA: AUTHOR

Abstract

As shown in Fig. 1, locations of key pads 10 are premeasured. Numerical control (NC) data for other pads 10 can then be calculated by linear interpolation between the two closest measured locations in accordance with the following formulas: (see original)

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Method of Generating Precise Numerical Control Data on a Distorted Surface

As shown in Fig. 1, locations of key pads 10 are premeasured. Numerical control (NC) data for other pads 10 can then be calculated by linear interpolation between the two closest measured locations in accordance with the following formulas: (see original)

The ceramic substrates 14 have metallic surface pads for mounting a plurality of chips 16 and interconnecting wires 18, as shown in Fig. 2. For automated processes on large substrates, NC data must be precalculated because the distortion associated with firing precludes the use of nominal dimensions. A previous approach was to measure the location of the center of each chip site and use the nominal bond pad offsets to calculate NC data. This method proved to lack the precision required.

A superior method was developed, in which the location of key bonding pads is measured. These pads lie at the intersections of wiring channels. When NC data on a particular pad is needed, measured data on the closest measured pads is used, according to the previously described scheme.

1

Page 2 of 2

2

[This page contains 5 pictures or other non-text objects]