开云体育I have several questions about smt solder mask templates.? A while back I ordered some bare pc boards from/for the Adafruit Si5351 pll modules. The board is small as about an inch by 3/4" or so. When I ordered the boards from JLCPCB I also ordered a stencil (unframed). When they arrived the stencil was on a piece of stainless steel about 11x17 inches.? Did I mention that the board it was for is only an inch by 3/4 inch?? I wondered if I had ordered the framed stencil if it would have been board size.? A few nights ago I was doing some internet searching and ran across an Adafruit series on stencils:One of those articles recommended this stencil frame which is a glorified screen printing style frame: Unfortunately that frame is $1000 so that is way out of my hobby budget!? Does anyone know of a much cheaper stencil frame than the Madell tech one? The next questions deal with how to cut the stencil.? I want to be able to lay the stencil on the board so that the stencil is exactly the size of the pc board and registers correctly.? I do not know how to do that.? If I lay the stencil on the pc board then I can not cut the stainless steel without moving it which looses registration.? So the question is how do I trim the stencil to board size and keep it so it registers correctly?? I asked JLCPCB that question but they did not understand the question and told me to put registration guides in the gerbers (that would not help). I had also bought a stencil from ProtoAdvantage for the TSSOP10 Si5351 chip but that was a big mistake.? The TSSOP10 footprint is a very thin 2x5 footprint and it was almost impossible to get it registered over the pc lans to apply solder paste because there was nothing else to reference against (in/on the frame) and with the very tiny slits I never was able to get it aligned on the board and apply paste.? I ended up just hand soldering the IC but there has to be a better way to do it. Do you have any suggestions? Thank you. Jim Pruitt |
