Browse Prior Art Database

Close Proximity, Concentrated Light, Crack Detection

IP.com Disclosure Number: IPCOM000037992D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Krol, CM: AUTHOR [+3]

Abstract

An inspection technique for pin grid array ceramic substrates enhances the detection of cracks. The technique works in the following fashion.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Close Proximity, Concentrated Light, Crack Detection

An inspection technique for pin grid array ceramic substrates enhances the detection of cracks. The technique works in the following fashion.

A pin grid array substrate 1 (Fig. 1) is inserted into an inspection fixture 2. A concentrated light source 3 (Fig. 2), such as a fiber optics bundle, is inserted through the bottom of an inspection table 4 such that the concentrated light source is flush with the top surface of the table. The fixture is then placed directly over the concentrated light source (Fig. 3).

The light which travels only the distance of the pin head 5 (Fig. 3) remains concentrated as it passes through the substrate. The surface area directly above the light source is highly illuminated. The intensity of the light gradually decreases with increasing radial distance from the center of the light source creating a shadowing effect. The entire surface of the substrate is inspected using a microscope at 10x. Cracks are detected between the area of high illumination and no illumination.

Disclosed anonymously.

1