This whole test thing has evolved to a point where we cheat more anf more often as Peter says. We probe, poke, dig, and otherwise make a mess of what we're trying to defend as good solder joints. One of our boards, though not that densely populated by some standards, has 1900 test pads on the board's bottom side. Most are not on an IPC "approved" grid. For that reason, many cannot be tested at all even with a funnel plate. Another of our boards, not at all unique, physical test points on the bottom side adhereing to IPC grid and size requirements. However, half the physical test points have been eliminated because much of the circuit has components capable of being tested using boundary scan. The devices allowing boundary scan have built in circuitry, or registers for lack of a better term, providing a network, or bus, that can almost self test with proper programming using only a four pin header thus eliminating the need for many traditional test points. Boundary scan provides many opportunities not only to minimize test points, but to design a concurrent test strategy that functions very well to determine fault or defect not capable of being done any other way. Combinint this with effective and effective process management at the board design, fabrication, and assembly levels, a high degree of defect determination can be assured notwithstanding the ability to eliminate the barbaric act of stabbing to death otherwise good solder joints. Earl --------------------------------------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------