Browse Prior Art Database

Method of Measuring the Circuit Board Temperature During Drilling

IP.com Disclosure Number: IPCOM000041333D
Original Publication Date: 1984-Jan-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Kloepfer, J: AUTHOR

Abstract

During the drilling of circuit boards with laminated copper planes, a thermocouple is formed when the hard metal drill touches the copper planes. The resultant thermovoltage depends on the cutting edge temperature. For evaluation, the thermovoltage is derived from the cold end of a bared copper plane and from the drill, using a sliding contact system in which there is no additional thermovoltage. By selecting an appropriate copper plane, the temperature characteristics of the board can be localized. The drilling of circuit boards leads to a highly undesirable smearing of the epoxy resin at high drilling temperatures and to a caking of the bore walls of the copper planes. The drilling temperature depends on several parameters, such as time, speed, advance, cutting edge geometry, etc.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 80% of the total text.

Page 1 of 2

Method of Measuring the Circuit Board Temperature During Drilling

During the drilling of circuit boards with laminated copper planes, a thermocouple is formed when the hard metal drill touches the copper planes. The resultant thermovoltage depends on the cutting edge temperature. For evaluation, the thermovoltage is derived from the cold end of a bared copper plane and from the drill, using a sliding contact system in which there is no additional thermovoltage. By selecting an appropriate copper plane, the temperature characteristics of the board can be localized. The drilling of circuit boards leads to a highly undesirable smearing of the epoxy resin at high drilling temperatures and to a caking of the bore walls of the copper planes. The drilling temperature depends on several parameters, such as time, speed, advance, cutting edge geometry, etc. To date, the actual drilling temperature could not be measured, so that the influence of these parameters could not be measured either. This is facilitated by the described method which permits measuring at accurately defined depths the influence these parameters exert on the board temperature, thus optimizing the drilling parameters for various types of circuit boards. The figure is a schematic of the basic measuring set-up comprising the drilling spindle 1, the hard metal drill 2, the hard metal brush 3, and the holder 4, preferably made of Cu, as a sliding contact system without any additional thermovoltage. The boar...