Post by thread:[OT]: How to make PCB at home?

David VanHorn wrote: > >Interesting thought... roll-your-own Gerber photoplotter, eh? Given the > >diameter of the average fiber, a larger pad could take a while to plot, > >though. Wonder if it's practical? > > Better than gerber, it's "Direct to PCB", making your audio amplifier sound > more lifelike than you ever dreamed it could, by eliminating distortions > caused by the intermediate processes. :) Hmmm. White LED with or without fiber optics, then lensing installed into "different pens" with different apertures for larger spot sizes. Some plotters could "auto-load" different apertures this way. Or a micro zoom lens to create different aperture sizes? Center these well, though - Tough, do-able. Dubious on those Audio Amp claims, though - As we all know, Tubes are what's necessary for reducing those distortions <LOL!> Mark -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use spam_OUTlistservTakeThisOuTmitvma.mit.edu?body=SET%20PICList%20DIGEST

> >White LED with or without fiber optics, then lensing installed into >"different pens" with different apertures for larger spot sizes. Some >plotters could "auto-load" different apertures this way. Or a micro >zoom lens to create different aperture sizes? Would a white LED expose as well as UV? >Center these well, though - Tough, do-able. Wouldn't the nib on the pen be already centered, and the right size? IOW, a 3 mil pen should have an N mil hole right down the center already, right? So it's just a matter of documenting the offset, and telling the plotter it's got an "N" mil pen instead of what's on the label. >Dubious on those Audio Amp claims, though - As we all know, Tubes are >what's necessary for reducing those distortions <LOL!> Just because YOU've got a tin ear... :) -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use .....listservKILLspam@spam@mitvma.mit.edu?body=SET%20PICList%20DIGEST

The pcb photo resist is not very sensitive... many minutes of exposure needed with typical UV sun lamps. I have been tossing the fiber delivery method over for quite a few years... I would love to get hold of a UV laser source to see if the writing speed could be made a reasonable value.... anyone out there have access to a laser lab at the university and could try some trial exposures on standard sensitized pcb material? Standard photo methods do not need nearly the same exposure times. Maybe a white led probe and standard film would work in a plotter. The downside is the darkroom chemicals required to develop the film. Big laser available? How about the cnc approach by vapourizing the copper right off the board. ======================================================= Lawrence Glaister VE7IT email: lgKILLspamjfm.bc.ca 1462 Madrona Drive http://jfm.bc.ca Nanoose Bay BC Canada V9P 9C9 ======================================================= {Original Message removed}

David VanHorn wrote: > >White LED with or without fiber optics, then lensing installed into > >"different pens" with different apertures for larger spot sizes. Some > >plotters could "auto-load" different apertures this way. Or a micro > >zoom lens to create different aperture sizes? > > Would a white LED expose as well as UV? It would depend on the photosensitivity of the PCB's coating, good point though. Research before implementing <G> Hmmm, UV LED's? <G> Blue LED's are worth a look, you do want a good reliable even-intensity spot. Mini arc lamp? <G> I usually use direct photo transfer, no expertise claimed, I'm brainstorming <G> > >Center these well, though - Tough, do-able. > > Wouldn't the nib on the pen be already centered, and the right size? > IOW, a 3 mil pen should have an N mil hole right down the center already, > right? So it's just a matter of documenting the offset, and telling the > plotter it's got an "N" mil pen instead of what's on the label. Yep, true. Optical path isn't guaranteed to be as centered as the pen unless you MAKE it so, though. Many pen feeders can grab a pen in any orientation IIRC when they change pens? > >Dubious on those Audio Amp claims, though - As we all know, Tubes are > >what's necessary for reducing those distortions <LOL!> > > Just because YOU've got a tin ear... :) Thanks a LOT! <G> Mark -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use .....listservKILLspam.....mitvma.mit.edu?body=SET%20PICList%20DIGEST

On Thu, 12 Oct 2000, Mark Willis wrote: > Dubious on those Audio Amp claims, though - As we all know, Tubes are > what's necessary for reducing those distortions <LOL!> > > Mark And here I thought all I had to do was use black Magic Marker around the edge of my CD to keep the light beams from leaking out! (seriously, someone swore that worked... apparently they saw it on the Internet on some audiophile site, which explains a lot!) Dale --- The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-requestKILLspammitvma.mit.edu

> And here I thought all I had to do was use black Magic Marker > around the > edge of my CD to keep the light beams from leaking out! (seriously, > someone swore that worked... apparently they saw it on the > Internet on > some audiophile site, which explains a lot!) No, no, no - it is a GREEN pen you're supposed to use. And not just any old green pen, it has to be a specific type of green pen, available from selected, overpriced stockists. This was from some audiophile magazines a few years ago - you know, the sort that debate the merits of titanium spiky bits vs "aircraft grade" alumin(i)um to support the separates... "The ear can't hear as high as that. Still, it ought to please some passing bat..." Peter -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestKILLspammitvma.mit.edu

>No, no, no - it is a GREEN pen you're supposed to use. >And not just any old green pen, it has to be a specific type of green pen, >available from selected, overpriced stockists. Nah, RED pen. The green one is for classical music, the RED is for hot rock and heavy metal. I've heard of a blue pen used for Blues, but I haven't heard it till now :o( --------------8<-------Corte aqui-------8<-------------- All the best!!! Alexandre Souza RemoveMExandinhoTakeThisOuTinterlink.com.br --------------8<-------Corte aqui-------8<-------------- -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

On Fri, 13 Oct 2000, Bond Peter S-petbond1 wrote: > > And here I thought all I had to do was use black Magic Marker > > around the > > edge of my CD to keep the light beams from leaking out! (seriously, > > someone swore that worked... apparently they saw it on the > > Internet on > > some audiophile site, which explains a lot!) > > No, no, no - it is a GREEN pen you're supposed to use. You are right, I stand corrected. It was indeed a specific green pen. > And not just any old green pen, it has to be a specific type of green pen, > available from selected, overpriced stockists. > > This was from some audiophile magazines a few years ago - you know, the sort > that debate the merits of titanium spiky bits vs "aircraft grade" > alumin(i)um to support the separates... I swear, if I were less ethical... if ever there was a market segment populated by people with no technical knowledge, above-average gullibility and too much cash for their own good, it's the car audio freaks. I could sell 00-gauge copper cable in different color jackets at a couple bucks a foot if I marketed it right, as long as it was "optimized for thundering bass"... Dale --- The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov -- http://www.piclist.com hint: To leave the PICList TakeThisOuTpiclist-unsubscribe-requestEraseMEspam_OUTmitvma.mit.edu

> I swear, if I were less ethical... if ever there was a market segment > populated by people with no technical knowledge, above-average gullibility > and too much cash for their own good, it's the car audio freaks. I could > sell 00-gauge copper cable in different color jackets at a couple bucks a > foot if I marketed it right, as long as it was "optimized for thundering > bass"... > > Dale There ya go - business plan for 2001. "Botkin's Wire And Swampland Boutique" And yes, some people will buy anything - a local show here actually found more than a few people who'd been suckered into buying and paying for installation of spy-holes for clear glass doors -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestEraseME.....mitvma.mit.edu

On Fri, 13 Oct 2000 10:34:05 +0100, you wrote: >>Big laser available? How about the cnc approach by vapourizing the copper >>right off the board. > >>Well, I DO have this 100mW argon unit sitting here.... > >they are building the worlds most powerful pulsed laser just across the yard from me at the moment. Somehow I think that PCB manufacture will be even lower priority than an idle process though... {:)) ..now there's a thought.... make the PCB by vapourising off the copper you don't want! -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestspam_OUTKILLspammitvma.mit.edu

> Dubious on those Audio Amp claims, though - As we all know, Tubes are > what's necessary for reducing those distortions <LOL!> Hot Source Fets Forever!!!!!!!!!!!! Always remembering that a lot of the tube versus transistor debate was carried out before nice effects such as T.I.M. were appreciated. Even now there's no guarantee that we are 100% certain how the signal processor between (and connected to) your ears reacts to a given semi-arbitrary form of signal handling. I personally have always had a good working engineering hearing range up to a bit over 10 kHz with a low pass filter that's staggeringly sharp above this, so I'm not one to subjectively assess the merits of the various claims. RM -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu

How's this: 1. Build a table that can move a PC board in one dimension in 1/300" increments with no cumulative error. [Old plotter anybody?] 2. Create a UV LED bar containing LED's on 0.1" centers. Over the LEDs is a mask containing 1/300"+ holes on 0.1" +/- 0.0005" centers [this is the tricky part :-)]. The holes need to be a bit oversize so that consecutive stripes will overlap a bit. 3: Mount the LED bar over the PC board on the table. The mask can almost be in contact with the board. 4: Attach the LED bar to an indexing mechanism that allows it to move perpendicular to the direction the PC board in 1/300" +/- 0.0005 steps (with no cumulative error). Now, to plot the board: repeat until done: Run the board from one end to the other. Index the LED bar one step. Run the board back. Index the LED bar one step. I figure you should be able to move the board a good 1" (300 steps) per second. Reversing direction should be about 1/10 of a second, which should give you plenty of time to index the LED bar. It only takes 300/0.1 = 30 passes to do the entire board. Thus, a 5" board would take about: 30 passes/board * 5 " * 1"/second ; for scanning + 30 passes/board * 0.1 second ; for reversing This comes to 150 seconds + 3 seconds = 153 seconds. That's pretty fast. Now you may find that due to lash in the PCB board that you need to do all the 'writing' in one direction. This would double the time. Also, this is assuming that you can get enough UV intensity to draw this quickly. Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu

Bob Ammerman wrote: {Quote hidden}> > How's this: > > 1. Build a table that can move a PC board in one dimension in 1/300" > increments with no cumulative error. > [Old plotter anybody?] > > 2. Create a UV LED bar containing LED's on 0.1" centers. Over the LEDs is a > mask containing 1/300"+ holes on 0.1" +/- 0.0005" centers [this is the > tricky part :-)]. The holes need to be a bit oversize so that consecutive > stripes will overlap a bit. > > 3: Mount the LED bar over the PC board on the table. The mask can almost be > in contact with the board. > > 4: Attach the LED bar to an indexing mechanism that allows it to move > perpendicular to the direction the PC board in 1/300" +/- 0.0005 steps (with > no cumulative error). > > Now, to plot the board: > > repeat until done: > > Run the board from one end to the other. > Index the LED bar one step. > Run the board back. > Index the LED bar one step. > > I figure you should be able to move the board a good 1" (300 steps) per > second. > Reversing direction should be about 1/10 of a second, which should give you > plenty of time to index the LED bar. > > It only takes 300/0.1 = 30 passes to do the entire board. > > Thus, a 5" board would take about: > > 30 passes/board * 5 " * 1"/second ; for scanning > + 30 passes/board * 0.1 second ; for reversing > > This comes to 150 seconds + 3 seconds = 153 seconds. > > That's pretty fast. Here's an idea Bob, how about use a laser to "scan" across the board, with a spinning mirror. Sould be easy enough to index. Then just move the board through in one pass, and the laser scans across it and obviously turning laser on and off will give the exposure. This system only has one axis motor to move the board (less junk for me to fix later) and the spinning mirror can be stepper/flywheel driven for easy indexing and very low mechanical wear. Yes there will be some compensation needed for the different laser "angle" from board centre to board edge, but simply using a very high-res mirror indexing system with software compensation would work. Since this would scan the entire board it would work just as well with pos/neg emulsions. Should be pretty quick, and only one main expense for the board traverse axis, ie, rails, linear bearings etc. Hey, just thought, laser printers use a rotating lens and laser that is probably suitable for photo emulsions since it is suitable for the laser drum... You could kill an old laser printer and apart from running it slower and using rails for the board traverse (I wouldn't trust rollers) you would have a real fine and reliable system... -Roman -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu

> >I swear, if I were less ethical... if ever there was a market segment >populated by people with no technical knowledge, above-average gullibility >and too much cash for their own good, it's the car audio freaks. I could >sell 00-gauge copper cable in different color jackets at a couple bucks a >foot if I marketed it right, as long as it was "optimized for thundering >bass"... Most of the ones I hear have uncontrolled woofers, leading to flatulent bass. -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu

On Fri, 13 Oct 2000, Alan B. Pearce wrote: > >Most of the ones I hear have uncontrolled woofers, leading to flatulent bass. > > Did you not know? that is the heartbeat of the aliens inside looking for some friendly people. Then they will be sadly disappointed when I hurl water balloons (or more unfriendly objects) through their open windows. Dale --- The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov -- http://www.piclist.com hint: To leave the PICList @spam@piclist-unsubscribe-request@spam@spam_OUTmitvma.mit.edu

On Fri, 13 Oct 2000 10:22:22 -0400, you wrote: {Quote hidden}>How's this: > >1. Build a table that can move a PC board in one dimension in 1/300" >increments with no cumulative error. >[Old plotter anybody?] > >2. Create a UV LED bar containing LED's on 0.1" centers. Over the LEDs is a >mask containing 1/300"+ holes on 0.1" +/- 0.0005" centers [this is the >tricky part :-)]. The holes need to be a bit oversize so that consecutive >stripes will overlap a bit. > >3: Mount the LED bar over the PC board on the table. The mask can almost be >in contact with the board. > >4: Attach the LED bar to an indexing mechanism that allows it to move >perpendicular to the direction the PC board in 1/300" +/- 0.0005 steps (with >no cumulative error). > >Now, to plot the board: > >repeat until done: > >Run the board from one end to the other. >Index the LED bar one step. >Run the board back. >Index the LED bar one step. > >I figure you should be able to move the board a good 1" (300 steps) per >second. >Reversing direction should be about 1/10 of a second, which should give you >plenty of time to index the LED bar. > >It only takes 300/0.1 = 30 passes to do the entire board. > >Thus, a 5" board would take about: > >30 passes/board * 5 " * 1"/second ; for scanning >+ 30 passes/board * 0.1 second ; for reversing > >This comes to 150 seconds + 3 seconds = 153 seconds. > >That's pretty fast. ..erm not much faster than normal laser-print plus UV expose..... and rather more expensive. Oh, and 300DPI is not enough. You need 600dpi for decent quality - the reason being that the normal PCB routing grid is 0.025" , i.e. 1/40 inch. 600 divides by 40, 300 does not, so you get uneven line widths and clearences. -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestKILLspammitvma.mit.edu

----- Original Message ----- From: "Dale Botkin" <TakeThisOuTdale.....TakeThisOuTBOTKIN.ORG> To: <TakeThisOuTPICLISTKILLspamspamMITVMA.MIT.EDU> Sent: Friday, October 13, 2000 11:29 AM Subject: Re: [OT]: How to make PCB at home? {Quote hidden}> On Thu, 12 Oct 2000, Mark Willis wrote: > > > Dubious on those Audio Amp claims, though - As we all know, Tubes are > > what's necessary for reducing those distortions <LOL!> > > > > Mark > > And here I thought all I had to do was use black Magic Marker around the > edge of my CD to keep the light beams from leaking out! (seriously, > someone swore that worked... apparently they saw it on the Internet on > some audiophile site, which explains a lot!) It's worse than that. You can't just use any old pen you know, it has to be a special green marker pen designed for the job. Luckily some kind soul is selling these pens to the audiophile community for the bargain price of 20USD. Can I interest you in buying one? They also help avoid bit-corrosion on your valuable data CDs. . -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other "[BUY]:","[AD]:" =Ads