3 Replies Latest reply on Jun 27, 2012 11:04 PM by sabitha.jamal

    PCB conformal coatings anyone?

    ed_smith

      Is anyone using conformal coatings on their PCBs to reduce the effects of moisture (or maybe dust or mould)? If so, are you generating the manufacturing data for these coatings using ExpeditionPCB (or FablinkXE)? If not, why not, are there any specific problems you are facing trying to use our tools to generate manufacturing data for these coatings?

       

      Thanks, Ed

        • 1. Re: PCB conformal coatings anyone?
          strangd

          Hi Ed:

           

          I have always cross hatched the board image in the assemble drawing to show the areas that should be covered before applying conformal coatings and primers. Usually protected from the conformal coating by covering the parts with Kypton tape.  Connectors, switches and other parts that have voids that should not be filled with the conformal coatings are 3D objects that are not described well enough by the software to automatically cut the tape.  Things like mounting holes and other 2D shapes could have a user layer that holds a shape to be export to DXF that then could imported into a laser die cutter.  But just using a user layer to hold the cross hatching has been all that has been done in the past.

           

          Protective covering techneques change if the board is to be dripped or painted.  This would lead to a variant situation in the data export?

           

          Some parts like glass diodes should be sleeved before being conformal coated.  Is there a method of calling out the size of the sleeve and the sleeve length followed by the total amount used?

           

          Dwain

          • 2. Re: PCB conformal coatings anyone?
            yu.yanfeng

            Hi Ed,

             

            Yes. There are PBAs need to deposit conformal coating to avoid monisture or high potentials. In telecom, Lot of  ASLC PBAs are coated with conformal coating. We just add a note in assembly instruction, not data need to output.

             

            In today's pcb, some of componet's pads need OSP whiling other still in HASL, so we have to output the data to support PCB fab.

             

            Yanfeng

            • 3. Re: PCB conformal coatings anyone?
              sabitha.jamal

                 Hi Ed

               

                         We are alsoprocessing conformal coating for protecting the boards and components from different moisture parameters, We have given the  X, Y location and its perimeter for the excluding the specified area  to teach to machine for autometed process of conforamal coating. I am eager to know what we can get from expedition PCB for conformal coating machine.Is any other valuable and easy method is getting from this?

               

               

               

               

              Thanks and Regards

              Sabitha