Daan, Two suggestions:- More zones will give more control over the profile (although different peoples prejudices about profile shape may suit different numbers of zones better!). As well as the increased throughput (assuming the overall length and therefore belt speed is increased) there is another possible advantage in that a board will spend less time with one end in one zone and one end in the other. This can reduce the temperature gradient (front to back) in the board which, if the board has a high in plane conductivity can also reduce the overall difference in temperature profile between the front and back of the board. David Whalley >Does anyone know a good reason, besides the possibility of having a >higher throughput-rate, to invest in a 7-heating-zone reflow oven (with >forced convection) instead of a similar machine with only 5 >heating-zones ? > >Daan Terstegge ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################