--- In si-list@xxxxxxxxxxxxxxx, "Sol Tatlow" <Sol.Tatlow@xxxx> wrote: > Steve is absolutely right to > advise against non-symmetrical > board stacks, and here's an > example why: ... I'm soaking this stuff up. Straight as a banana. Got it. > ... ask your PCB fabricator ... Actually, now you mention it, they came up with our new stackup. We (I say "we", but this is before I joined) specified a stackup that is almost as laughable as your banana boards. They threw it in the trash and made a suggestion which we accepted. Note that the entire board design was done assuming one stackup but when the board house needed to use a completely different one it was approved without pause. See what I'm up against? > ... perhaps ask your populator > as well ... Too small and not enough experience. We're moving elsewhere. As far as I can see, the boards with the new stackup are acceptably flat. > ... type of soldering ... It's reflow. > ... lead-free soldering ... Oh, boy. Graham. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: http://www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu