Browse Prior Art Database

Method of Determining the Degree of Cure of Epoxy Resins on Printed Circuit Boards and Cards

IP.com Disclosure Number: IPCOM000043692D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Druschke, F: AUTHOR [+4]

Abstract

The described method permits the non-destructive determination of the degree of cure and the glass transition point (Tg) on printed circuit boards and cards. Cards and boards are produced from copper planes and epoxy resin layers which are laminated. During lamination, it is essential that temperatures and process times are reached which are such that the epoxy resin is sufficiently cured, for insufficiently cured resins become plastic and deformed in the subsequent processes, whose temperatures exceed the glass transition point of the epoxy resin. For determining the degree of cure of the epoxy resin, part of a virgin area on the front face of the finished boards or cards is polished. After polishing, the board is heat-treated at a temperature exceeding the Tg.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 92% of the total text.

Page 1 of 1

Method of Determining the Degree of Cure of Epoxy Resins on Printed Circuit Boards and Cards

The described method permits the non-destructive determination of the degree of cure and the glass transition point (Tg) on printed circuit boards and cards. Cards and boards are produced from copper planes and epoxy resin layers which are laminated. During lamination, it is essential that temperatures and process times are reached which are such that the epoxy resin is sufficiently cured, for insufficiently cured resins become plastic and deformed in the subsequent processes, whose temperatures exceed the glass transition point of the epoxy resin. For determining the degree of cure of the epoxy resin, part of a virgin area on the front face of the finished boards or cards is polished. After polishing, the board is heat-treated at a temperature exceeding the Tg. Before and after heat treatment, the polished surface is scanned with a surface- measuring device for recording the surface profile. A comparison of the two surface profiles indicates the degree of deformation in micrometers. Experiments have shown that the polished surface scarcely changes at temperatures < 130OE. At higher temperatures, the measured profile depths ranged from 3 to 15 mm, depending upon the degree of cure of the epoxy resin. Samples that were heated to 160OEC, repolished after surface measurement and then heated to 180OEC did not show any further changes after the second heating step. These sampl...