Thanks Gary.

Although "tenting" refers to covering the pad (in our case via pad) we are
only allowing encroachment of solder mask to .002' of the finished drill
hole. Does IPC have guidelines for this methodology?  And, is this a cost
addeder as well? (we are questioning our board suppliers right now)



Thanks,
Ray







Gary Ferrari <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
07/03/2002 09:54 AM
Please respond to "TechNet E-Mail Forum."; Please respond to Ipcgary


        To:     [log in to unmask]
        cc:
        Subject:        Re: [TN] Guidelines for tenting via's


Ray,

You can find information about tenting vias in IPC-2221 Generic Standard
on Printed Board Design, section 4.5.1 Solder Resist Coatings. It does
indicate that the maximum size for tenting is 1.0 mm for Class 1 and 2 and
0.65 mm for Class 3 equipment. The tenting acceptability for larger sizes
should be discussed between user and supplier.

Regards,

Gary