Well, I think the other responses have just about covered all the variables. I have seen this problem and wanted to add a little. As they said, check you aspect ratio, but if you had a stencil that was working (why did you change to a new one?) and it is the same as this one, you probably have the correct ratio. I would not use nickel plating. You should electropolish laser cut. I have tried it with and without electropolish and results lean toward better release with electropolishing. A rough sidewall will not release as well, there is more surface area then. Think about paste release like a sand-pail on the beach when you are building a sand castle. It is trapezoid shaped and smooth on the inside. If it worked better rough, sand-pail manufacturers would texture the inside of the pails. The smooth surface offers less surface area and easy release. Do check your paste as Steve G. mentioned. I had a similar problem a few years back and we looked at the stencil and process, then tested the paste and found it was a bad batch. It was way thick and upon further investigation found it had been exposed to extreme cold (froze) during shipment. You may be in an area that you don't have to worry about this, but it could have gotten too warm also. Or it could just be bad from the manufacturer. But we had paste clogging like crazy with that bad paste. Plugging a stencil manufacturer ehh Steve. Well, I have tried several and always end up back at IRI. I have had outstanding success with IRI and would not trade a stencil from them for anyone elses. I have not tried Beam-on since they are in CA and IRI has a facility closer. But IRI has an East and West coast facility to support the entire US. Good luck solving the problem. Brad Kendall Hella Electronics Corp. [log in to unmask] on 07/10/98 05:13:28 AM Please respond to [log in to unmask]; Please respond to [log in to unmask] To: [log in to unmask] cc: (bcc: Brad Kendall/Hella North America Inc.) Subject: [TN] Electropolishing Laser-Cut Stencils Hi all, We are currently having problems with a laser-cut stencil that is electropolished and nickel plated with 9-mil openings. The paste does not release well from the apertures. We are having to wipe after every print. The board is fixtured well and we have been using the same paste for the last two years. We had a different laser-cut stencil in production from a different manufacturer with the same 9-mil opening, but this stencil was not electropolised or nickel-plated. With this stencil, the paste release was excellent and we never had to worry about wiping. Does anyone have any input into whether or not laser-cut stencils should be electropolished and nickel plated? I have heard contradicting opinions on this subject. One source has said that you do not want to electropolish laser-cut stencils because the rough laser walls will give you a better paste release. Whereas, another source has said that the smooth laser walls will give you a better paste release. Also, what benefit does nickel plating give you? Does the paste tend to roll better with nickel plating? Do you tend to get more or less paste deposit on the boards with nickel plating? Does it increase the life of the stencil? Has anyone using laser stencils seen major differences between the quality of different stencil manufacturers? Any input into this subject would be greatly appreciated. Thanks, Todd ################################################################ 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 ################################################################