----- Original Message ----- From: "WILLIAMS MICHAEL" <k9qho6...@sbcglobal.net> To: <amsat-bb@amsat.org> Sent: Tuesday, November 08, 2011 12:08 AM Subject: [amsat-bb] Etching a KLM RHCP/LHCP PCB
Hi Mike, K9QHO > I've completed and etched one side#1 of the PCB with Press and Peel. OK, > > Side#2 needs to be etched. the artwork is very basic and can be completed > by hand and Rub-On Etch Resist. I had to drill 8 alignment holes to help > line up the artwork to each side. OK, but remember that you have to drill 9 alignment holes only to solder the relay and that all holes on PCB must be inside metallized. > > Question #1: > I don't want the etching solution to leach through the holes. I had some > donuts to cover the holes, but they are so old that the glue is no good. > Is there anything that can temporarily fill or cover the holes until side > #2 is completed? Mike, I would temporarily fill the holes using a two component epoxy adesive that become very hard when it dry so that the etching solution cannot leach through the holes. A suitable two component epoxy adesive is called UHU-PLUS http://www.stirlingshop.de/UHU-Plus-Epoxy-Adhesive-Endfest-300 As soon side #1 and #2 are etched by the acid soluction it is necessary to drill again the holes to remove the epoxy adesive but remember that all 9 holes must be metallized inside so that you must fit a hollow rivet into each hole and than solder it to both side #1 and #2 of PCB The holes metallization is very important because othervise you cannot properly solder the relay pins on both sides of the PCB When soldering the relay pins do not use too much heat with a high power soldering iron because the relay pins are not copper but steel that becames immediately oxidated at high temperature. > > Question #2: > Has anyone used clear packing tape to cover the areas where the copper > is to be protected or will the etching solution just eat it up with the > copper? In my opinion the etching solution just will eat it up with the copper. > > You have to admit this isn't a typical AMSAT-BB question. In projects > before this, I just used side #2 as the ground plane. > In my opinion you have place good usefull questions to AMSAT-BB Don't forget that you must protect the PCB and relay from the water so that in a separate email I have sent to you a set of pictures to show you how I have solved the problem, > 73, > > Mike (K9QHO) > 73" de i8CVS Domenico _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
