Doug, First and foremost, get directly involved with your customer at the PCB design stage. The type and quantity of BGA devices will affect layer count, internal and external routing, test-ability, and soldermask apertures. I have seen all types of surface finishes specified; HASL, OSP, hard and soft Ni/Au, and solid solder deposits. I know of one fabricator that supplies BGA product with solder bumps on the all SMD sites but the BGA with the BGA and PTH sites OSP. The assembler does not print any paste, just sticky flux for the SMD's. They're using BGA's with 63/37 balls which supply the solder to the joints. Probably the most significant impact on the PCB fabricator is at electrical test. Depending on your technology level of fixturing software, fixturing, and test equipment, you can easily get into multiple test fixtures that take many hours to solve. Getting involved early in the PCB design can prevent having 4-625 pin CBGA's in a 3"x3" area. Regards, Dennis Mitchell Zycon Corp. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: BGA Author: [log in to unmask] at corp Date: 1/10/96 5:32 PM -- [ From: Doug Jeffery * EMC.Ver #2.10P ] -- Question? What does BGA technology mean to board fabricators? Do we have to become solder paste experts and reflow solder again.. I thought we got rid of that problem.....:).... No Seriously, what are the responsibilities at fabrication for creating boards to accept BGA's? Thanks? Doug Jeffery Electrotek..