Comments on: Homemade PCBs http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/ Microcontrollers Electronics Hobby Sun, 28 Mar 2010 03:07:45 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Berni http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1431 Berni Tue, 02 Sep 2008 16:34:46 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1431 Well its kinda logical to be careful with something that eats metal. And yeah donut use a screwdriver or something to get the board out of the acid, because it will start to rust like crazy.(I seen a screwdriver that had this happened to it) Well its kinda logical to be careful with something that eats metal. And yeah donut use a screwdriver or something to get the board out of the acid, because it will start to rust like crazy.(I seen a screwdriver that had this happened to it)

]]> By: Alan Wang http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1430 Alan Wang Tue, 02 Sep 2008 02:20:26 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1430 Iron (III) Chloride is indeed acidic when dissolved in water. It should be noted that it is very corrosive (be careful in other words) Iron (III) Chloride is indeed acidic when dissolved in water. It should be noted that it is very corrosive (be careful in other words)

]]> By: dfowler http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1429 dfowler Tue, 19 Aug 2008 23:44:03 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1429 Markham, I think you will be OK with the scanner glass but you might read more at the links below. You may have some blockage but you can adjust your exposure time to compensate. I vaguely remember that Plexiglas is not so good at passing UV but I could be wrong. The PCB exposure rigs I have used in the past did have glass. Plastic (Plexiglas) Transmission http://www.newton.dep.anl.gov/askasci/eng99/eng99272.htm Glass Transmission http://www.newton.dep.anl.gov/askasci/phy00/phy00890.htm Markham,

I think you will be OK with the scanner glass but you might read more at the links below. You may have some blockage but you can adjust your exposure time to compensate. I vaguely remember that Plexiglas is not so good at passing UV but I could be wrong. The PCB exposure rigs I have used in the past did have glass.

Plastic (Plexiglas) Transmission
http://www.newton.dep.anl.gov/askasci/eng99/eng99272.htm

Glass Transmission
http://www.newton.dep.anl.gov/askasci/phy00/phy00890.htm

]]> By: Markham http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1428 Markham Tue, 19 Aug 2008 19:47:17 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1428 I have a dead scanner that I plan to convert into a UV exposure chamber. Would the glass end up blocking the UV light? Or am I thinking of infrared? I have a dead scanner that I plan to convert into a UV exposure chamber. Would the glass end up blocking the UV light? Or am I thinking of infrared?

]]> By: XTL http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1427 XTL Sat, 09 Aug 2008 22:10:57 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1427 Oh, and no metal containers obviously :-D Oh, and no metal containers obviously :-D

]]> By: XTL http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1426 XTL Sat, 09 Aug 2008 22:08:52 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1426 Something this particular guide seems to be skimping on is that that ferric chloride is vicious stuff. Especially with the copper dissolved in it. If this article really is new information to someone, they should really be warned about what they're dealing with. As for an earlier comment, I believe it's a salt and the solution is obviously acidic. The reaction to copper isn't entirely due to that but you can do the etching with other suitable acids (plus peroxide IIRC). Do not allow it in drains or nature, it should be handled as hazardous waste and given to the waste disposal authorities just like batteries, old oils, paints etc. It also stains everything really badly :) http://en.wikipedia.org/wiki/Iron(III)_chloride Google for more. There's tons of resources on pcb making and etching with lots of tricks and variations. Something this particular guide seems to be skimping on is that that ferric chloride is vicious stuff. Especially with the copper dissolved in it. If this article really is new information to someone, they should really be warned about what they’re dealing with.

As for an earlier comment, I believe it’s a salt and the solution is obviously acidic. The reaction to copper isn’t entirely due to that but you can do the etching with other suitable acids (plus peroxide IIRC).

Do not allow it in drains or nature, it should be handled as hazardous waste and given to the waste disposal authorities just like batteries, old oils, paints etc.

It also stains everything really badly :)

http://en.wikipedia.org/wiki/Iron(III)_chloride

Google for more. There’s tons of resources on pcb making and etching with lots of tricks and variations.

]]> By: dfowler http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1425 dfowler Tue, 05 Aug 2008 05:39:19 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1425 OK I fixed the articles pictures. Sorry for the confusion. OK I fixed the articles pictures. Sorry for the confusion.

]]> By: Gary http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1424 Gary Mon, 04 Aug 2008 16:40:31 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1424 Has anyone found a good source for photoresist in the USA? Has anyone found a good source for photoresist in the USA?

]]> By: Berni http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1423 Berni Sun, 03 Aug 2008 10:54:29 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1423 You can do it without a drill press if you use a small drill and hold it right. Use bouth hands to hold it at 90 degrees and your fine.Remember to have clamp down smaller boards it will start spining around the drill bit and break it otherwise.A crocodile clip works fine for that. You can do it without a drill press if you use a small drill and hold it right. Use bouth hands to hold it at 90 degrees and your fine.Remember to have clamp down smaller boards it will start spining around the drill bit and break it otherwise.A crocodile clip works fine for that.

]]> By: Steve Chamberlin http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/comment-page-1/#comment-1422 Steve Chamberlin Sat, 02 Aug 2008 02:38:13 +0000 http://www.uchobby.com/index.php/2008/07/27/homemade-pcbs/#comment-1422 I think the part I was missing is that you start with a board that's copper-plated, and that has some non-conductive material underneath, and then you eat away the copper you don't want. Is that right? Initially I thought it was just a solid copper sheet, copper all the way through, and you covered up the areas that you didn't want to be conductive. I think the part I was missing is that you start with a board that’s copper-plated, and that has some non-conductive material underneath, and then you eat away the copper you don’t want. Is that right? Initially I thought it was just a solid copper sheet, copper all the way through, and you covered up the areas that you didn’t want to be conductive.

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