Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-04 by Simao Cardoso
... If you still didn t use/tried, maybe facing the paper side with ink down to the dry film and placing the uv source 1 meter apart could be an easy test. To
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Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-03 by Philip Pemberton
... The UV box has a vacuum pump built in -- there are four UV tubes in the bottom, covered with a sheet of glass, then four in the top with a sheet of
Re: [Homebrew_PCBs] Re: Today's board - TT 11/8.66 rules
2009-06-03 by DJ Delorie
One thing I always do is run a 50 mil trace around the outline of the board, so that none of the real traces are the ones on the outside edge.
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-03 by DJ Delorie
Looks like you got the exposure just right. Are you using some type of vacuum hold-down? I found I had to do something about that because the weight of the
Re: Today's board - TT 11/8.66 rules
2009-06-03 by RICHARD HEILIGER
I use an 8 year old Minolta PagePro 1250 laser printer. I have used the factory toner and remanufactured cartridges from two different sources. All give the
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-03 by Philip Pemberton
... That would be because I left View Attachments set to Admins Only . It s set to All Users now, so anyone should be able to see that file. ... That s
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-03 by DJ Delorie
... I do not have permission to use that feature :-( ... I don t have a double-sided exposure box, but... For DS boards, what I do is include targets on my
Re: [Homebrew_PCBs] Homemade Schmartboard ridges
2009-06-03 by DJ Delorie
I ve played with a schmartboard, and do fine-pitch smt by hand, and I don t see it as much of a benefit. Heck, if you re doing reflow, the parts mostly align
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-03 by Philip Pemberton
... I think I ve sorted it... A 960-second (16-minute) exposure on CIF 0.8mm D/S pre-coated board produced a step of 11. Shifted exposure by -3 stops to get
Re: [Homebrew_PCBs] Homemade Schmartboard ridges
2009-06-03 by leon Heller
... From: David Griffith To: Sent: Wednesday, June 03, 2009 5:32 AM Subject: [Homebrew_PCBs] Homemade
Re: Homemade Schmartboard ridges
2009-06-03 by kianush.azari
... no we can use this method Spread a photoresist over the board about .2mm thick. Mask as
Homemade Schmartboard ridges
2009-06-03 by David Griffith
The biggest problem, IMHO, with doing surface-mounts by hand is aligning the pins with their corresponding pads. The Schmartboard line of prototyping boards
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by DJ Delorie
So get a PCB with film, cut it into strips the width of your step gauge, and do a binary search of your timer s range ;-) Really, if you have a step gauge, you
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by Philip Pemberton
... Which seems even more off than my estimates -- other types of photoresist I ve looked at specify an exposure time of between two and three minutes. The
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by DJ Delorie
... Oops, I was looking at the soldermask specs, not the photofilm specs.
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by Philip Pemberton
... Their website disagrees: Exposure energy: 25-60mJ/cm^2 (60-25) = a range of
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by DJ Delorie
... ThinkTink s film requires 150-300 mJ/cm2 ... That s 21 minutes. Sounds about right for an initial step gauge test. I d use 16 just to make the math easier
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by Philip Pemberton
... I got the Microtrak and the CPD5 developer from Farnell (they re within driving distance, and it cost less to drive down there than pay the UPS hazchem
RE: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by Marc Sulfridge
... The problem is one of units. The first number you calculated is the lamp intensity in W/cm^2=J/(s*cm^2). Your dry film dose is specified in mJ/cm^2=
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-02 by Philip Pemberton
... The math for step 4 seems utterly wrong though: # Calculate an initial exposure time by dividing the power output of your UV lamp (in Watts) by the total
Re: [Homebrew_PCBs] Today's board - TT 11/8.66 rules
2009-06-02 by Piers Goodhew
... Just getting back to this - I get a few holes in the toner in larger areas, but never actual holes through the copper. I am just fooling with this and
Re:Today's board - TT 11/8.66 rules
2009-06-02 by sailingto
I ve been playing with the GBC laminator today. I jumpered one of the thermal switches so I could get a higher temperature on the 3 mill setting. I have a
Re: The return of the Homebrew-PCBs Wiki
2009-06-01 by James Newton
... This has also been my experience. http://techref.massmind.org doesn t require any registration to post new information. It checks for common spam words,
Re: The return of the Homebrew-PCBs Wiki
2009-06-01 by James Newton
... If the wiki were associated with the Yahoo list, this point might have some validity. How will people who find the list find the wiki? More importantly,
Re: [Homebrew_PCBs] Re:Today's board - TT 11/8.66 rules
2009-06-01 by DJ Delorie
... My boards tend to have enough traces on them that almost never is often enough to ruin most boards. What toner are you using that sticks at 260F? Mine
Re:Today's board - TT 11/8.66 rules
2009-06-01 by RICHARD HEILIGER
I don t do anything that complex. I set the temperature on my external control to 260 *F, The $25 GBC laminator. Takes about as long to heat up as it takes to
Re: [Homebrew_PCBs] Today's board - TT 11/8.66 rules
2009-06-01 by DJ Delorie
... It leaves a pretty thick layer of green stuff, too. The peeled-off film is clear where the artwork was. It claims to seal the toner, filling in the
Re: [Homebrew_PCBs] Today's board - TT 11/8.66 rules
2009-06-01 by Myc Holmes
DJ, From my own testing, when using the green stuff , you actually flattening and evening out the toner a bit. After removing the paper, the toner is
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-01 by DJ Delorie
... The last step held is the last step that has *any* resist remaining, at least with negative resist. I ve found that you get one step completely cured,
Today's board - TT 11/8.66 rules
2009-06-01 by DJ Delorie
Did another board today; the lines were big enough to use toner transfer so I did it that way, to try out the hotter laminator too. Things that didn t go so
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-01 by leon Heller
... From: Philip Pemberton To: Sent: Sunday, May 31, 2009 11:27 PM Subject: Re: [Homebrew_PCBs]
Re: [Homebrew_PCBs] Copy/Paste and Toner Transfer
2009-06-01 by DJ Delorie
... One of the weird things about PCB is that it was designed BEFORE the schematic capture stuff (way before, IIRC). It has its own way of entering the rats
Re: [Homebrew_PCBs] The return of the Homebrew-PCBs Wiki
2009-06-01 by Alessio Sangalli
... I totally disagree with this. First I also have wikis, blogs, etc, and spammers have no trouble to register. Second, this way you are cutting away a good
Re: [Homebrew_PCBs] Re: The return of the Homebrew-PCBs Wiki
2009-06-01 by Piers Goodhew
Doing my best to keep this on topic and civil: 1 - I m on a few lists and it drives me nuts that you need to keep giving mostly the same answers a few times a
Re: [Homebrew_PCBs] Copy/Paste and Toner Transfer
2009-06-01 by Piers Goodhew
... He s right (except for the slash in OS X, that s a bit IBM ;-) ), EAGLE lite is also free for noncommercial use and runs very well on OS X (like all CAD
Re: [Homebrew_PCBs] Copy/Paste and Toner Transfer
2009-06-01 by DJ Delorie
... gEDA/PCB work just fine on Mac OS/X, and they re free. ... You can use PCB without gEDA for that :-)
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-06-01 by DJ Delorie
... Relevent messages (search for delorie exposure step ): http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/20864
Re: [Homebrew_PCBs] Re: The return of the Homebrew-PCBs Wiki
2009-06-01 by Zoran A. Scepanovic
... Hash: SHA1 ... %
Re: [Homebrew_PCBs] Re: The return of the Homebrew-PCBs Wiki
2009-05-31 by Philip Pemberton
OK, it s pretty clear I ve ruffled a few feathers here. That was honestly not my intention... To start with, I wanted to collect at least some of the mass of
Re: [Homebrew_PCBs] Re: The return of the Homebrew-PCBs Wiki
2009-05-31 by Philip Pemberton
... I ve just turned on the Rollback and View History features. View History allows you to view the differences between the current version of a page and any
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-05-31 by Philip Pemberton
... No need to shout! :) I ve spent this afternoon doing a few tests on some cheap Maplin pre-coated laminate, with Seno Develop 110 developer (the one that
Re: The return of the Homebrew-PCBs Wiki
2009-05-31 by James Newton
Ok, look, Philip, your a good guy, and I very much appreciate the stuff you ve done and published. But lets just think about this for a second: - you are
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-05-31 by leon Heller
... From: Philip Pemberton To: Sent: Sunday, May 31, 2009 4:47 PM Subject: Re: [Homebrew_PCBs]
Copy/Paste and Toner Transfer
2009-05-31 by macmyke01
Hi everyone, I don t know if this has been already posted, but I thought it might be helpful to anyone who just wants to whip out a quick board without paying
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-05-31 by Philip Pemberton
... I did a quick search of the archives (and had a read of the page on Thinktink s website, but that was about as clear as mud) and didn t find anything
Re: The return of the Homebrew-PCBs Wiki
2009-05-31 by Steve
... And if a spammer erases stuff to add their spam, how will those users restore the lost info? Steve Greenfield
Re: The return of the Homebrew-PCBs Wiki
2009-05-31 by Steve
... Although that would be an improvement on allowing anyone who registers, there is still the issue of the dedicated spammer that still manages to get in
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-05-30 by DJ Delorie
... Check the archives; I ve described this before a few times, but in a nutshell: You put the gauge on some PCB and expose it for some time, like 8 minutes,
Re: [Homebrew_PCBs] Setting exposure with a step gauge
2009-05-30 by Zoran A. Scepanovic
... Hash: SHA1 ... % there you have the explanation on using step gauge -- Best regards,
Setting exposure with a step gauge
2009-05-30 by Philip Pemberton
Hi guys, My two Stouffer 21-step step gauges arrived the other day, and I d like to use them to figure out an exposure for a positive-acting precoated