Ian, Using conformal coatings as an under fill is not recommended. The material is not "designed" for that type of use (curing/dryng issues due to lack of exposure to the atmosphere plus CTE issues). Please use materials that are designed for use as an underfill. This is paticularly true for class 3 products! David A. Douthit Manager LoCan LLC Fox, Ian wrote: >Fellow techies, a BGA related question. We're just starting to design BGA's >into some new designs which are class 3 high rel assemblies and I am asking >myself questions about the ability to adequately conformally coat under the >packages. Our standard coating is a solvent based acrylic and we are using a >456PBGA device and a 429CBGA device, both on 1.27mm pitch, as the maximum >sizes so far and I'd be interested to hear what other class 3 builders have >experienced when applying the coating. > >Regards >Ian Fox >Goodrich ECS >Birmingham >UK > >--------------------------------------------------- >Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 >----------------------------------------------------- > > > > --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------