Patent ID: 6672500
Filing Date: 2004-01-06
Classification: B23K,H05K

Abstract:
A method for measuring the cooling rate and temperature differential between a top surface and a bottom surface of a printed circuit board, said method comprising the steps of:providing said printed circuit board having a plurality of through-holes therein and including a module on said top surface thereon, said module having a plurality of lead free solder joints, at least one of said plurality of lead free solder joints being located relative to at least one of said plurality of through-holes; extending a thermocouple wire through said at least one through-hole; positioning a first thermocouple within said at least one through-hole, within or proximate said at least one of said plurality of lead free solder joints and connecting said thermocouple wire to said first thermocouple; positioning a second thermocouple on said bottom surface proximate said at least one through-hole and connecting said second thermocouple to said thermocouple wire to form a thermocouple pair with said first thermocouple; reflowing said plurality of lead free solder joints; cooling said at least one lead free solder joint through a solidification temperature range; and measuring said temperature differential between said top and said bottom surfaces with said first and second thermocouples substantially through said solidification temperature range.