Browse Prior Art Database

GRADE MARKING OF TESTED WAFER-LEVEL SEMICONDUCTOR DIE VIA PHOTORESIST

IP.com Disclosure Number: IPCOM000006714D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2002-Jan-24
Document File: 1 page(s) / 58K

Publishing Venue

Motorola

Related People

Stephen G. Sheck: AUTHOR

Abstract

Process variations and defects (random and system- atic) necessitate that semiconductor wafers be electri- cally tested to identify defective die. Traditionally, these reject die have been marked with an ink dot to indicate at package assembly that such die are defective and must not be assembled.

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 60% of the total text.

Page 1 of 1

0 M MO-LA

/NC. Technical Developments Volume 17 December 1992

GRADE MARKING OF TESTED WAFER-LEVEL SEMICONDUCTOR DIE VIA PHOTORESIST

by Stephen G. Sheck

  Process variations and defects (random and system- atic) necessitate that semiconductor wafers be electri- cally tested to identify defective die. Traditionally, these reject die have been marked with an ink dot to indicate at package assembly that such die are defective and must not be assembled.

  Traditional methods of applying such ink dots have beenviaelectrotnechanical,pneumaticandvacuumassisted mechanisms called inkers. Inking originally was done in an "online" mode (ii as you test) and has advanced in recent years to an 'ofnine" mode (ink on another machine some time after you test). Inkless probe is the latest advance, where electronic maps travel with the wafers to assembly, instructing the pick and place equipment which die to assemble. The major advantages of h&less probe are time savings and no messy inking problems, however, it has been slow to be put into practice indus- try wide. The messy problems associated with inking include ink dot size variation, ink splatter caused by heavy application and/or ink that is too fluid, and mechanical damage to the die caused by the inking mechanism strik- ing the die surface.

  This variation, splatter and damage can be avoided by parallel application of photoresist or other photosen- sitive material via screen print as the inking medium. Small dots or squares of ph...