Tenting is nothing more than having no openings in the solder mask over vias. You normally do it on both sides of the board. I am mystified by their cost of thousands of dollars. I do this routinely and specify 100% electrical test on bare boards. If you have components on both sides of the board but the test points for the bottom side pads are not accessible on top, then you would need a clam shell test fixture. This can be avoided by making all nodes accessible through test points on one side of the board. Even so, a clam shell test fixture shouldn't cost thousands of dollars, unless it is a large board with lots of 0.5mm spacing pads. For boards with all the components on one side, tented vias don't cost anything. The only caveat is that vias can no longer be used as test points, so you may have to add some. Seth Goodman Goodman & Associates 7687 Leta Way Verona, WI 53593 Tel (608)833-7687 FAX (608)827-2631 -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Ryan Jennens Sent: Monday, November 23, 1998 12:02 PM To: [log in to unmask] Subject: [TN] Covering Vias Howdy all- Three more days! When I asked our board fab house to mask the vias on the bottom side of one of our boards to avoid the shorting which has been plaguing us, I was told that they could do it, but for a cost of thousands of $. They said that they would have to make a clamshell fixture to test the bare board before they ship it to us. What are my other options for avoiding shorts to these vias which are near pads. This happens under BGA parts and also near some surface mount parts. Is tenting more than just covering the vias with solder mask? Thanks in advance for the wonderful insight which always follows these inquiries! Ryan Jennens Phoenix Engineering Design, Inc. ################################################################ 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 ################################################################ ################################################################ 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 ################################################################