hi, there's no doubt that a thermal grease would lower the thermal resistance between the heat sink and the package. the question is whether or not a lower thermal resistance is necessary. if it is, use the grease; if it isn't, leave it alone. phil -----Original Message----- From: Bissonnette, Jean-Francois [mailto:[log in to unmask]] Sent: Tuesday, January 16, 2001 10:01 AM To: [log in to unmask] Subject: [TN] Collar Heat-sink Hi technetters, I'm looking at a design of a PC Ass'y with a collar heat-sink for a TO-3. In the specs it is said to have an excellent thermal conductivity. There is no indication of thermal compound to be used with it. With all heat-sink I've used in the past we had to use such compound... shouldn't any used with this kind of heat sink??? Thanks. JF WABTEC CORPORATION CONFIDENTIALITY NOTE The content contained in this e-mail transmission is legally privileged and confidential information intended only for the use of the individual or entity named herein. If the reader of this transmission is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this transmission is strictly prohibited. --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------