In a message dated 9/7/06 8:10:01, [log in to unmask] writes: > I have seen thermal cycling data from two different sources that suggest > high aspect ratio PTH >9:1 fail more quickly than an 0805 chip resistor > solder connections. > > Hi, While this is generally true, it is not the aspect ratio that you need to consider, but the PCB thickness and the drilled hole diameter independently. Werner --------------------------------------------------- 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 -----------------------------------------------------