I purchased a stencil cleaner from ECD(yes, the same people who make the M.O.L.E.) We use a noclean solder paste, but isopropyl alcohol is required to wash the stencils. All the stencil cleaners that I looked at could use IPA, but because they had electric motors, they required a fire supressionsion system, at a considerable cost. Many used heated solutions, and I had some of the same questions you have raised, espcially about the bonding to the frames/stencil. The ECD system uses air motors, no electricity is required, thus no fire supression system(the system is grounded). It has been working well for two years. We use it to clean misprints and stencils. This is a spray system, with the IPA at room temperature. We have used it on fine pitch(20mil) aperatures. I have heard that ECD is selling their stencil cleaning system to Austin American. Good luck E. Holton [log in to unmask] ------------- Original Text From: C=US/A=INTERNET/DDA=ID/TechNet-request(a)ipc.ipc.org, on 1/16/97 3:21 PM: I am currently in the process of evaluating SMT stencil washing equipment at our facility here. I am looking at ultrasonic technology versus coventional spray systems. What I would like from you all are any pros & cons, that might come with a particular technology. For example, I have heard that the stencils should not be exposed to temperatures higher than 110 degrees F. The theory behind this being that, the stencil is made up of three different materials: 1. The outer frame usually constructed of Aluminum frame 2. The screen portion that bonds the outer frame with the metal foil 3. The metal foil that has the apertures, stainless steel And so, when a stencil is subjected to these higher temperatures of >140 F in a conventional spray system(hot water), the materials with different thermal coefficients of thermal expansion, expand and contract at different rates. And in doing so, can cause irreversible stretch in the metal foil. In the case of fine pitch applications this could translate into significant off alignment with the land pads on the board during printing. What I would like to know is if this holds true? And if so, is there any research findings available that I could look into that would provide me with the answers, or any experience with such findings. Also with certain wash chemistry, the adhesive that bonds the foil and the screen and the outer frame tends to loosen up. Another question would be, the effectiveness of cleaning fine pitch apertures, 20mils & below with one or the other system? Also, how about cleaning other materials such as misprinted boards, boards with adhesive, wave pallets, etc. Would appreciate your effort in answering the above questions Thanks Nasir [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************