From: Thomas Weeks To: Ben Stembridge Date: Thu, 09 Feb 1978 00:58:22 +0500 Subject: Re: CAD software for PCB's Around 11-Jun-98, Ben Stembridge typed: >> >> >> Well..for MY 10 pitch layouts, I used DPAINT with a grid resolution of 36x36 >> and then just printed in 360x360 resolution... Then inverted the image and >> xeroxed onto iron on transfer sheet... it's ok.. but home etching usually >> sucks... >This is my first project using etched PCB's , previously I had always used >breadboards, wirewraping and the like. Here at the university they have a >machine that you can give it your CAD designed board in a file and it >automagically makes the board. The guy I know said that if I can get him >the file(gerber,GBL) he'll make it for me. > But now that you mentioned iron-on-transfer-sheet , - what kind of >tolerance can you achieve using that method? I will have traces going >between the pins that are .100" apart but the pads that they solder to >will tighten it up even more (to the same size as traces that run between >pins on ISA slots). You can play with the methodology... but I've had some problems with fine pitch digital boards using that method... I would try a less dense circuit first... > I've seen etching kits - the ones with green solution and some solid >copper PCB's. Could I manage with that? That's the type of echant you use with the iron on method... You iron on the toner, then submerge it in the echant (ferrocloric acid), etch and agitate, then remove and rinse. Sounds easy eh? heh.. well... that's why I tell you to start off with a simple test circuit.... >My project is to make a 2 zorro slot adapter for the A500. ooo... Good luck! I COULD be done.. but you need to make your traces as fat as possible... and one suggestion... don't put "etch" the holes in the pads for the drill points... go ahead and make them solid and THEN after etching just drill them out.. you'll end up with a better quality board. >> >> p.s. mind if I publish this letter as a Tech Tip? >> -- >By all means go right ahead ;) >thanks Ok... You can get the iron on transfer sheets from Jameco and Digikey if I am not mistaken.. about $1/sheet. Tom D TEk -- __________________________________________________________________________ / Thomas W. Weeks |Team AMIGA Commodore Amiga 500/030 40MHz \ | A&M EET/Telecom Grad '95 | /// Hacked Into Black Tower Case, | | Authorized Amiga Tech (7yrs) | __ /// 9M RAM, SyQuest 44M, 700M-o-SCSI | | Contact Me @ | \\\/// IBM 286 Hardware Emulator, | | o------------o | \XX/ Home Brew Audio A/D, HP48GX | | Email: tweeks@texas.net |"Amiga, The Computer for the Creative Mind"TM| |Web:lonestar.texas.net/~tweeks|"Mac, The Computer for the Rest of Us"TM | \_____________________________|____________________________________________/