Actually, looking at Bill's address, he IS the laminate manufacturer! oops! At 08:57 02/09/99 -0700, you wrote: >The first thing that comes to mind is why don't you let your laminate supplier do this >for you? I will assume you have a good reason for doing this your self. How many high >are you pressing this package, when I worked at a lamination facility we did that kind >of thing 18 panels high in a 48" x 72" format with a large quality of wedge shape wood >blocks against the bolsters. > >Another little trick is to replace some of your 7628 with unclad laminate in the >middle. That way you only need two plies of the prepreg on each side of the unclad >against the copper foil. This will reduce the slippage considerably. > >Good Luck > >Chuck Brummer > >Wang, William (Suzhou Laminate) wrote: > >> Chuck: >> I'm sorry that I didn't provide enough information. The slippage >> happens to 1.5 mm or 1.6 mm double sided laminate during the lamination >> process (copper foil, 8 ply 7628 prepreg, copper foil, not PCB >> multilayer lamination). It happens from time to time, sometimes zero >> percent though we change nothing in our process. We reduce the resin >> content of 7628 prepreg, the slippage percentage decrease but lead to >> under-thickness problem. >> >> Thanks and best regards >> William Wang >> ---------- >> From: Chuck Brummer >> To: [log in to unmask] >> Subject: Re: [TN] Copper Clad Laminate Slippage >> Date: Wednesday, September 01, 1999 10:52PM >> >> Let us count the ways, sorry just a little joke. In my last bit of >> advice I suggested >> that the problem could be fixed by increasing the resin to glass ratio. >> But too much >> resin not enough glass can make your package slip. When was the last >> time you checked >> your press for parallelism? You might be pushing the package to one >> side or corner. >> If your gel time is off the prepreg can get very slippery. How many >> layers? Are your >> making a multilayer that has little "C" stage core and very much >> prepreg. Do you need >> to block the load. When we last used vacuum assisted lamination I made >> some aluminum >> frames to assure the load was centered and resisted slippage because we >> use some >> conformals that can cause slippage when the stack was higher. When we >> do not use the >> vacuum assist we reduce the stack height. >> >> Dan Brandler, where are you? You should probably have some insight for >> this guy. >> >> Chuck Brummer >> [log in to unmask] >> >> Wang, William (Suzhou Laminate) wrote: >> >> > I'm a greenhand of copper clad laminate, can anyone tell me why >> > copper clad laminate could slip during press and how to prevent from >> > slippage? (We use vacuum assisted hydraulic press) >> > >> > Thanks and best regards >> > William Wang >> > >> > ############################################################## >> > 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 Gayatri Sardeshpande at [log in to unmask] or >> > 847-509-9700 ext.5365 >> > ############################################################## >> >> ############################################################## >> 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 Gayatri Sardeshpande at [log in to unmask] >> or >> 847-509-9700 ext.5365 >> ############################################################## >> >> ############################################################## >> 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 Gayatri Sardeshpande at [log in to unmask] or >> 847-509-9700 ext.5365 >> ############################################################## > >############################################################## >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 Gayatri Sardeshpande at [log in to unmask] or >847-509-9700 ext.5365 >############################################################## > > ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################