Rick, You cannot use Durapol in the reflow oven. It will burn up in just a hundred or so passes. You need to use Durastone or Delmat. You may also want to consider using a fixture that you can run through the screen printer to avoid handling after printing. Jim ----- Original Message ----- From: "Rick Thompson" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, May 07, 2003 12:48 PM Subject: [TN] Reflow Fixture Opinions Sought We have a customer who is requesting that we use a reflow fixture consisting of a Durapol plate with removable tooling pins to accomodate several different large PWBs through the reflow process. These fixtures would run on the flat belt rather than edge rails and would require that we remove large (16"x12") fully loaded boards from the conveyor rails to install on these fixtures prior to reflow. Components on the board range include a number of BGAs and micro-BGAs. The intent of the fixtures is to keep the board from flexing during reflow. My concern is that all the handling and flexing of boards with components in solder paste is going to increase the chances of soldering problems due to part separation from the paste if the board is flexed. Question: Has anyone used this type of concept on large, densely populated boards. Comments on pros and cons? Any other insights would be appreciated as I'm looking for supporting evidence to dissuade them from this approach which is primarily aimed as saving fixture costs over dedicated SMT fixtures. Thanks in advance. Rick Thompson Sr. SMT Process Engineer SMTEK International, Inc. +1 (805) 532-2800 [log in to unmask] --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 -----------------------------------------------------