Fred, We are currently testing most BGA product on 100 mil grids with 3.75" long pins on a single fixture. However, the need for multiple fixtures (split nets) is on the rise due mainly to increasing density of BGA's and SMD's around BGA's. I agree with tbresnan@multek that there is a need for double density test; on a small but growing scale. We have not yet experimented with splitting tests between the grid and prober. Our most significant factor in creating a single fixture is the density of test points around the BGA. This is coupled with the fixturing software's ability to efficiently assign all test points to grid. Regards, [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Re: Bare Board Test PCBs with BGAs Author: [log in to unmask] at corp Date: 2/12/96 5:25 PM Fred... The only strategies available today are the "double-density" BBTesters that give you an extra pin in the center of the std .100 grid and the "flying probe" type testers. Most folks today are using a combination test, flying probe in the high density area of the PWB and standard BBTester for the remainder of the board. Unfortunately, the testers of the world do not have a single solution for high volume throughputs. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Bare Board Test PCBs with BGAs Author: [log in to unmask] at internet_gateway Date: 2/12/96 3:16 PM Can anyone share successful Bare Board Test strategies and Equipment Requirements when launching into BGA testing? For example: A 19 X 19 array, 1.27 mm pitch, 357 pin, PBGA with 23 mil diameter NSMD solder pads on a board with two signal, one power, and one ground plane. Can this be done using a 100 mil grid BBTester? Particularly useful would be your experience dealing with the obstacles and solutions to unforeseen problems. FRED J. PAUL: [log in to unmask] FLUKE CORPORATION Sr. Process Engineer POB 9090 M/S 55 PCB Operations EVERETT, WA 98206 direct: 206 356-5734 fax: 206 356-6070 Corporate: 206 347-6100