> On Mon, 7 Dec 1998, CONKNET wrote: > > > Successful test of .030 micro-bga's on traditional (bed of nails / grid) > > equipment is reliable and not too difficult to achieve. It does not require > > "double density" grids. It does require good fixture design. Test of 30 mil > > BGA's typically requires 3.75 inch multi-plate fixtures with 12 or 16 mil > > piano wire pins. Some care needs to be given to the Z axis load created by > > the test pins on thin boards. Although Pin Tilt can approach or exceed 1 > > inch, the pad size on BGA's make a big target relative to 15 mil QFP device, > > so targeting is not normally an issue. > > This technique has already saved the industry, or at least bought "this much" time. Probable knee breaker is the proximity to the next like device, cascading across a 12" board. Pray for peripheral arrays and adequate device-to-device pitch? ("But the parts fit!") Is there a guideline pins-per-square-inch-per-side- times-board-area where this technique saturates? When and where is the parasitics-based testing technology going to come rescue this situation? Haven't heard a peep on this for maybe a year, but I'll confess I haven't been looking. Promised to work on a probe-once-per-net basis rather than all endpoints. Or how about the "touchless" radiation/excitation? Regards to all, -- Jeff Seeger Applied CAD Knowledge Inc Chief Technical Officer Tyngsboro, MA 01879 jseeger "at" appliedcad "dot" com 978 649 9800 ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################