M.Sc. projects
--------------

Doug Edwards 



Title: Utility Software the PCB Unit.

For:  Conversion Course Students

Abstract:

A number of projects are available to write a suite of utility
programs for the Department's PCB (Printed-Circuit-Board) unit. No
knowledge of PCBs is required. The unit takes in board descriptions in
a format which drives a numerically controlled photoplotter. The
photplotter draws lines (tracks) and "pads" to produce artwork from which the
board is manufactured. We wish to enhance the reliability of the
finished product by ensuring that there is correspondence between
tracks and pads produced on the board and those implied by the
photoplotter description.

A numerically controlled board testing machine is available which
"probes" a board and determines whether there is electrical continuity
between two points. By analysing the photoplotter data, it is possible
to generate data for the board-tester which will check that there are
no "breaks" (caused by manufacturing defects) in lines on the board.

Currently missing from the testing software is the ability to check
that one track is not inadvertently connected to another
track. Testing each possible track against all other tracks would be a
possibility, but this is too time consuming to be practicable.  An
efficient algorithm needs to be developed which identifies those
tracks which are adjacent and restricts testing to those tracks so
identified.