Hi Technetletter We presently use a thermal plane with a direct contact of a 3 watts resistor for heat dissipation. Our board (class 3 military) was fabricated in 1986, we want to know if IPC require to use a thermal mounting plate and we want to know if we can still use the old method. I would like to know if manufacturers/designers have a guideline for this problem. Nancy Byrns Oerlikon Aerospace ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################