Browse Prior Art Database

Chip-Orientation Detector

IP.com Disclosure Number: IPCOM000060567D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Ting, YM: AUTHOR

Abstract

Misorientation of semiconductor chips in chip carriers occurring prior to the chip-placement-on-module operation adds to product rework costs. This article discloses an optical scheme for eliminating this problem, thereby increasing the yield of multi-chip modules at assembly. A number of device line operations between wafer dicing and chip packaging involve the manual handling of chips which contributes to their misorientation in chip carriers. Module rework and increased product cost due to such errors can be eliminated by use of the scheme illustrated in the Figs. 1 and 2. Vacuum picker A, without motor, as shown in Fig. 1, is employed to pick up chips from a chip carrier prior to their placement on a substrate (not shown).

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 82% of the total text.

Page 1 of 2

Chip-Orientation Detector

Misorientation of semiconductor chips in chip carriers occurring prior to the chip- placement-on-module operation adds to product rework costs. This article discloses an optical scheme for eliminating this problem, thereby increasing the yield of multi-chip modules at assembly. A number of device line operations between wafer dicing and chip packaging involve the manual handling of chips which contributes to their misorientation in chip carriers. Module rework and increased product cost due to such errors can be eliminated by use of the scheme illustrated in the Figs. 1 and 2. Vacuum picker A, without motor, as shown in Fig. 1, is employed to pick up chips from a chip carrier prior to their placement on a substrate (not shown). The chips are packaged in the carrier with their solder pads facing down and the chip is 'picked' on its reverse side. Fig. 2 shows the same vacuum 'picker' with a motor B added (allowing it to be rotated by 90-, 180-, and 270-degree increments), a video camera C (which is used to capture the pattern of the chip solder pads), an analog-to-digital (A/D) converter D (which converts the analog video signal to a digital signal), and a processor/comparator E, which processes the digital output and compares it with a predetermined solder pad pattern. If the result of the comparison is good (a match), the chip is placed on the substrate as presented. If the result of a comparison is a mismatch (or incorrect), the chip is...