Hi Ioan, PTVs filled with solder mask/epoxy during the soldering processes will experience less compressive loads on the copper barrel, and thus less tensile stresses which are part of the loading leading to innerlayer separation. During operationall use, this fill plys no significant reliability role. PTVs filled with solder of course offer no advantage during the soldering processes--they are filled during them. In operational use, fully filled PTVs are subjected to reduced loads on the copper barrel than empty ones, and PTVs with voids in the solder fill will experience localized higher loads due to the stress concentrations---having said this, it needs to be emphasized that this is only significant if the operational conditions are severe, such military and automotive. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904 E-mail: [log in to unmask], Website: www.engelmaier.com --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------