MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with their exposure and etch kit. Pretty straightforward "print pattern on transparency; place on PCB; expose to light; wash off exposed portion; etch" process. The "expose" part of this process consists of using MGC's "daylight" fluorescent lamp. If it's truly a "daylight" bulb, wouldn't direct sunlight work for this purpose? I presume this bulb is of a particular wavelength. What is it? Any other ideas to use this process to etch PCBs without their lamp? Thanks, -- Al, the usual
Photo-etch light source?
Started by ●March 4, 2007
Reply by ●March 4, 20072007-03-04
Usual Suspect wrote:> MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with their > exposure and etch kit. Pretty straightforward "print pattern on transparency; > place on PCB; expose to light; wash off exposed portion; etch" process. > > The "expose" part of this process consists of using MGC's "daylight" > fluorescent lamp. > > If it's truly a "daylight" bulb, wouldn't direct sunlight work for this > purpose? I presume this bulb is of a particular wavelength. What is it? > > Any other ideas to use this process to etch PCBs without their lamp?I use sunlight to expose all my boards. The only difficulty is waiting for a clear sky, so the exposure is predictable and the edges are sharp.
Reply by ●March 4, 20072007-03-04
"Usual Suspect" <reply@thegroup.net> wrote in message news:0001HW.C2104D2E025D5113F01826C8@news.sf.sbcglobal.net...> MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with > their > exposure and etch kit. Pretty straightforward "print pattern on > transparency; > place on PCB; expose to light; wash off exposed portion; etch" process. > > The "expose" part of this process consists of using MGC's "daylight" > fluorescent lamp. > > If it's truly a "daylight" bulb, wouldn't direct sunlight work for this > purpose? I presume this bulb is of a particular wavelength. What is it? > > Any other ideas to use this process to etch PCBs without their lamp? > > Thanks, > -- > Al, the usual >"daylight" flourescents are easy to get at your local home store -- as are the fixtures to run them -- buddy of mine used just one... but had some problems with fuzzing that I think would have been solved had he used 2 or 3 for a more even light source -- making an exposure box with 2 or 3 lamps -- the ones about 12" long, and a piece of plexi as the exposure surface is pretty easy.
Reply by ●March 4, 20072007-03-04
"John Popelish" <jpopelish@rica.net> schreef in bericht news:WOydnZ4O8KR3kHbYnZ2dnUVZ_t7inZ2d@adelphia.com...> Usual Suspect wrote: >> MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with >> their exposure and etch kit. Pretty straightforward "print pattern on >> transparency; place on PCB; expose to light; wash off exposed portion; >> etch" process. The "expose" part of this process consists of using MGC's >> "daylight" fluorescent lamp. If it's truly a "daylight" bulb, wouldn't >> direct sunlight work for this purpose? I presume this bulb is of a >> particular wavelength. What is it? Any other ideas to use this process to >> etch PCBs without their lamp? > > I use sunlight to expose all my boards. The only difficulty is waiting > for a clear sky, so the exposure is predictable and the edges are sharp.Waiting for a clear sky may take days or even weeks in this part of the world. Even then exposure time is a long shot. So for years I used a 120W high pressure mercury bulb, meant for streetlighting. It not only produced enough UV, it also produced a lot of visible light and even much more heat. So last year I got an obsolete A4 flatbed scanner and an old home solarium - "face browner" - and build a new exposure box. Works like a charm so the old one is for sale now :) The idea of the new exposure box is not new. Look at http://gathering.tweakers.net/forum/list_messages/730455 The text is Dutch but the pictures are universal. Exposure time is 2 min. Make sure the traces on the transparency are pitch black. I always stack two of them as one lets through too much UV and makes the etched copper look like a rats dinner. petrus bitbyter
Reply by ●March 4, 20072007-03-04
In article <45eb186d$0$27917$e4fe514c@dreader24.news.xs4all.nl>, pieterkraltlaatditweg@enditookhccnet.nl says...> > "John Popelish" <jpopelish@rica.net> schreef in bericht > news:WOydnZ4O8KR3kHbYnZ2dnUVZ_t7inZ2d@adelphia.com... > > Usual Suspect wrote: > >> MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with > >> their exposure and etch kit. Pretty straightforward "print pattern on > >> transparency; place on PCB; expose to light; wash off exposed portion; > >> etch" process. The "expose" part of this process consists of using MGC's > >> "daylight" fluorescent lamp. If it's truly a "daylight" bulb, wouldn't > >> direct sunlight work for this purpose? I presume this bulb is of a > >> particular wavelength. What is it? Any other ideas to use this process to > >> etch PCBs without their lamp? > > > > I use sunlight to expose all my boards. The only difficulty is waiting > > for a clear sky, so the exposure is predictable and the edges are sharp. > > Waiting for a clear sky may take days or even weeks in this part of the > world. Even then exposure time is a long shot. So for years I used a 120W > high pressure mercury bulb, meant for streetlighting. It not only produced > enough UV, it also produced a lot of visible light and even much more heat. > So last year I got an obsolete A4 flatbed scanner and an old home solarium - > "face browner" - and build a new exposure box. Works like a charm so the old > one is for sale now :) The idea of the new exposure box is not new. Look at > http://gathering.tweakers.net/forum/list_messages/730455 > The text is Dutch but the pictures are universal. > > Exposure time is 2 min. Make sure the traces on the transparency are pitch > black. I always stack two of them as one lets through too much UV and makes > the etched copper look like a rats dinner. > > petrus bitbyter > > >Stack 2 of them eh? I never thought of that. I used a tanning bulb for exposing the board when I did that stuff. I built an exposing table with a timer that kept the bulb on for 15 minutes. It had the timer built into the table, and a piece of soft wall conduit that supported the lamp so it was 12" from the board surface. Worked great too! Probably would have been more reliable using 2 transparencies. I have since switched to the photo paper method published by Thomas P. Goote, and I find very reliable and sufficiently accurate for my needs. FYI, I use ammonium persulfate to etch the boards I make. Check out his web page here; http://www.fullnet.com/~tomg/gooteepc.htm Have fun! - Tim -
Reply by ●March 4, 20072007-03-04
On a sunny day (Sun, 04 Mar 2007 18:14:40 GMT) it happened Usual Suspect <reply@thegroup.net> wrote in <0001HW.C2104D2E025D5113F01826C8@news.sf.sbcglobal.net>:> >If it's truly a "daylight" bulb, wouldn't direct sunlight work for this >purpose? I presume this bulb is of a particular wavelength. What is it? > >Any other ideas to use this process to etch PCBs without their lamp? > >Thanks,Sure, 250W photolamp at 30cm distance for 8 minutes. Except for DownUnder, where these lightbulbs will be illegal soon.
Reply by ●March 4, 20072007-03-04
On Sun, 04 Mar 2007 18:14:40 GMT, Usual Suspect <reply@thegroup.net> wrote:>MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with their >exposure and etch kit. Pretty straightforward "print pattern on transparency; >place on PCB; expose to light; wash off exposed portion; etch" process.I don't know about the MG system, but I have used sunlight a number of years ago. It works well, the only problem is that it's variable depending upon cloud cover and the time of year. Experiments are needed to get the exact exposure. I now use a Philips TUV 20 flouro lamp and it works fine. However, it is a short wavelength UV and the radiation is considered a little hazardous, I just take care to only switch in on when the artwork is all set-up and everything is covered. Barry
Reply by ●March 4, 20072007-03-04
In article <0001HW.C2104D2E025D5113F01826C8@news.sf.sbcglobal.net>, Usual Suspect <reply@thegroup.net> wrote:> Any other ideas to use this process to etch PCBs without their lamp?I've used a 100W mercury vapor lamp, up close and personal. Most of the resists are looking for some UV component. A metal-halide fixture will probably also work well, a sodium vapor light probably would not. 175W is probably easier to find than 100W, that just happened to be the lamp I had handy at the time. A carbon arc would be just dandy, and could offer some old-fashioned electro-mechanics for a bit of variety in your projects. -- Cats, coffee, chocolate...vices to live by
Reply by ●March 4, 20072007-03-04
On Sun, 04 Mar 2007 18:14:40 GMT, Usual Suspect <reply@thegroup.net> wrote:>MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with their >exposure and etch kit. Pretty straightforward "print pattern on transparency; >place on PCB; expose to light; wash off exposed portion; etch" process. > >The "expose" part of this process consists of using MGC's "daylight" >fluorescent lamp. > >If it's truly a "daylight" bulb, wouldn't direct sunlight work for this >purpose?Yes, but it's very hard to get an accurate exposure with sunlight.> I presume this bulb is of a particular wavelength. What is it? > >Any other ideas to use this process to etch PCBs without their lamp?I've heard that greenhouse fluorescent tubes (the kind used for hydroponics) work okay, but I don't have any personal experience with them. -- W "Some people are alive only because it is illegal to kill them." . | ,. w , \|/ \|/ Perna condita delenda est ---^----^---------------------------------------------------------------
Reply by ●March 5, 20072007-03-05
In sci.electronics.misc Lionel <usenet@imagenoir.com> wrote:> On Sun, 04 Mar 2007 18:14:40 GMT, Usual Suspect <reply@thegroup.net> > wrote:>>MG Chemicals sells pre-sensitized copper-clad PCB blanks for use with their >>exposure and etch kit. Pretty straightforward "print pattern on transparency; >>place on PCB; expose to light; wash off exposed portion; etch" process. >> >>The "expose" part of this process consists of using MGC's "daylight" >>fluorescent lamp. >> >>If it's truly a "daylight" bulb, wouldn't direct sunlight work for this >>purpose?> Yes, but it's very hard to get an accurate exposure with sunlight.>> I presume this bulb is of a particular wavelength. What is it? >> >>Any other ideas to use this process to etch PCBs without their lamp?> I've heard that greenhouse fluorescent tubes (the kind used for > hydroponics) work okay, but I don't have any personal experience with > them.I wonder guys, why wouldn't you just use a proper long-wave UV bulb? They are aplenty and dirt cheap... Any T8 BL or BLB works like a charm, doesn't require anything but regular fluorescent ballast to run and produces that very sub-400nm lightwave required for exposure... Why are you trying anything but a proper tool? Am I missing something? Just FUI -- that magical MGC lamp is just a 15 Watt T8 BL bulb in a regular fluorescent fixture... --- ****************************************************************** * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * ****************************************************************** -- Posted via a free Usenet account from http://www.teranews.com