Optical recognition of defective pins on VLSI chips using electron trapping material

Alastair D. McAulay; Junqing Wang

doi:10.1117/12.217670

Abstract

A method is investigated for fast online inspection of pins on very large scale integrated (VLSI) circuit chips prior to mounting on circuit boards. We image the edge of the VLSI chip containing the pins to be inspected onto electron trapping material (ETM) using Argon light. This writes an image of the pins to be inspected onto the material. Then we image an identical chip type with perfect pins onto the electron trapping material using IR light. This performs a subtraction between the two images. The output is read out with another IR beam and summed onto a detector. If the output exceeds an electronic threshold, pins are considered damaged. We show experimental results with pins separated by 0.2 mm to show practicality and speed of the approach. A second approach is explored in which the grating effect of the pins is used to form a self image. The same procedure is followed except that imaging lenses are no longer required. We show that there is no advantage in using self imaging with this approach.

Citation Download Citation

Alastair D. McAulay, Alastair D. McAulay, Junqing Wang, Junqing Wang, } "Optical recognition of defective pins on VLSI chips using electron trapping material", Proc. SPIE 2565, Optical Implementation of Information Processing, (28 August 1995); doi: 10.1117/12.217670; https://doi.org/10.1117/12.217670

ACCESS THE FULL ARTICLE

PERSONAL SIGN IN
Full access may be available with your subscription

Email or Username Forgot your username?

Password Forgot your password?

Show

Remember Email/Username on this computer

Remember Password

No SPIE account? Create an account
or Institutional Sign In via Shibboleth

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $14.40

Non-members: $18.00 ADD TO CART

Show All Keywords

Keywords/Phrases

Search In:

Publication Years