Earl, Your pictures are up! Go to: http://www.stevezeva.homestead.com -Steve Gregory- > Seth and other fine folks, > > I do a lot of work in the R/F MLB world. Who doesn't. In this regard, I > asked Steve if he'd kindly post two x-section images. Both show blind vias > not of the micro type. One is shown from a bucket shop not knowing what they > had done really was pretty good but for obvious plating problems. > > The first image shows a "normal" blind via that has been plated over. The > fill resin was formed in the sequential lamination process. I try to ignore > all the 7628 material but for its ability to fill the hole to the top with > resin. Then, the hole/resin fill was plated over. The hole diameter, as I > recal, was about ten mils. Therefore, it was producible through "norman" > drilling processes and should have shown no ill effects as the poor plating > shown. What's really important is the plating over the top. It is robust and > shows little depression, though exagerated by the micro section, at about a > mil or so. I rather like it as it is a near perfect depression and suits > BGA's very well though they need little help self aligning. > > The second (color) image shows a "normal" drilled blind via. I think Proto > Engineering provided this section (how are my latest boards coming?). What's > interesting here is the possible plating over capability. If filled > properly, like Sanmina's tech center process and others, it would be plated > over without much notice. >