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Browse Prior Art Database

Vision Vibration Inspection Tester

IP.com Disclosure Number: IPCOM000106116D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Halliday, D: AUTHOR [+2]

Abstract

Described is a technique of production testing for unsoldered joints on the gullwing legs of PLCC modules by visual means only. Manual probing and x-ray inspection of every joint is superceded. Closed circuit television is employed as the visual detector and a controlled frequency pulsed air jet is used to disturb weak connections.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 69% of the total text.

Vision Vibration Inspection Tester

      Described is a technique of production testing for unsoldered
joints on the gullwing legs of PLCC modules by visual means only.
Manual probing and x-ray inspection of every joint is superceded.
Closed circuit television is employed as the visual detector and a
controlled frequency pulsed air jet is used to disturb weak
connections.

      An electronics plant assembling gullwing legged modules on
printed circuit boards (PCB) has a requirement for a non-cotact test
that will show up any one leg that has no soldered mechanical bond to
the PCB.  The existing method was for the inspector to run a metal
pin along all legs, which can cause PCB damage, and watch for
vibration or movement.  Other requirements were for a 100% production
test on all product with data collection transmitted by LAN from the
test point to the central workstation evaluation control.  Also an
operator/user interface with automatic loading.  The solution that
satisfies the above criteria is disclosed below.

      The method is to have a pulsed air flow aimed at any one module
and to have images taken of the leg at a given/optimum frame rate
that by comparison with each other will show any vibration or
movement of the setup at the testing point.

      A PCB (1) under test has a module (2) with a leg (3) attached
to solder pad (4).  A stream of pulsed air (5) is directed by a
nozzle (6) on to leg (3).  The pulsed air is generated from a source
...