If you have PTHs Primarily, issues may occur in the PTHs. As you know, there are great CTE diff within them, with Cu=17, solder=25, epoxy x/y = 15 and epoxy z = 110-225 ppm/C. - copper cracks in the barrel's upper region ( copper corner cracks) - solder cracks in the same region (solder corner cracks) - barrel deformation cracks Micro vias - plating cracks, i.e. cracks along the copper barrel - barrel-to-trace cracks, i.e. interrupts between the barrel and the horizontal copper trace - delamination of the glass epoxy in the uppermost region around the vias These are the general issues which may happen. There should be lots of postings in TNs archive. And tons of reports on the web. Inge On 9 February 2011 18:12, Victor Hernandez <[log in to unmask]>wrote: > Folks, > > Given: > - FR4 > - Th. 0.094 inch > - Layer Count 20 > - Technology > o 4 tier totem pole stack micro vias > o Buried conductive filled blind vias > - Post 3x and 6x solder float test > - Cross section > > What are some of the expected anomaly to look for? > > Victor, > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 15.0 > 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.aspx?Pageid=E-mail-Forums for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 > ext.2815 > ----------------------------------------------------- > ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------