No problems that I know of apart from the hassle of rework. As you know, parylene has to be "sand-blasted" off to remove it, and if it gets underneath BGA's, it could make their removal pretty difficult. Do you plan to epoxy underfill the BGA's at all? It might be worth considering if you don't have such a plan. A capillary action flow-type underfill applied after the BGA has been mounted will support the BGA solder joints, but it has two other advantages in you case - 1) it is reworkable at soldering temperature and 2) it will act as a barrier to parylene getting underneath the BGA's and holding them to the board in a death grip. Peter Duncan "Houston, Terri" To: [log in to unmask] <Terri_Housto cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST [log in to unmask]> Aero/ST Group) Sent by: Subject: [TN] Parylene coating PBGAs TechNet <[log in to unmask] ORG> 11/10/01 12:35 AM Please respond to "TechNet E-Mail Forum." Hi folks, We're designing a board assembly, which has 2 PBGAs on it. The plan is to coat the boards with Parylene since they're going into an industrial environment. Is there any information in the industry about recommendations or problems in parylening board assemblies containing PBGAs? Thanks in advance, Terri --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 --------------------------------------------------------------------------------- [This e-mail is confidential and may also be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.] --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------