Hi Cheryl, How accurate is a stencil? Typically very accurate. The most common and best laser systems to manufacture stencils allow for accuracies well within 1 mil and can be used to produce accuracies within 0.5 mil. That means any aperture can be within 0.5 mil of its intended location. The aperture size can even be more accurate. But watch out, the intended aperture opening is the opening at the contact side of the stencil. The opening at the squeegee side is slightly smaller due to the trapezoidal shape of the aperture walls. All this presumes the operator knows what he or she is doing!! So I would not expect you to find a reason to throw away a stencil for inaccuracies. As we are discussing accuracies, when do you throw away a board because it is not accurate? But before you throw away a batch of inaccurate boards, it is sometimes possible to make a stencil just as inaccurate and allow you to use the boards anyway. Did you find any problems to make you ask your question? Regards, Ahne Oosterhof, A-Laser / Fine Line Stencil, Inc., Beaverton, OR. 503-641-9428 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Cheryl Tulkoff Sent: Thursday, April 07, 2005 11:05 To: [log in to unmask] Subject: [TN] Stencil Accuracy Does anyone have some guidelines on acceptance criteria for laser cut stencils? How far from nominal (% or actual) do you allow the stencil apertures to be before you would reject it back to your supplier? Thanks, Cheryl --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------