Ralph In downhole drilling the electronic units will often see 200 deg. C for several weeks or the tools may come out of the hole and lay in a snow bank in Alaska or Siberia for a a couple of weeks and then return to another hole for a repeat of the hot downhole opertion again. It requires some different techniques, solders, finishes etc. to withstand this harsh operating envirorment. Phil Hinton ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################