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2013-07-07 by brane2
... Fair enough, but in such environments I wouldn t act on your advice alone, I would check legal requirements first. One can not deal with such things on
2013-07-07 by brane2
Of course. I was thinking about twelve inches of lead just for an outer part of the shield. Im kind of lingering between Uranium and Kurchatovium for inner
2013-07-07 by Mitch Davis
... I used the rounded ones: http://capnstech.blogspot.com/2011/05/playpause-making-pcbs-at-home.html Works fine for me. (Admittedly my system is quite ghetto,
2013-07-07 by arvidj01
We seem to have strayed from the intent of my original question. Thanks to those that offered advice. I m planning on an LED solution with wide angle 120 to
2013-07-07 by Stefan Trethan
I m sure that caesium source had a fair number of warning signs....... That said, it doesn t cost anything to put a warning on the exposure box, to remind
2013-07-07 by Jim
I doubt that for home use, such exigencies are necessary. I know that my welders are dangerous. My rotary phase converter is dangerous. My 80 gallon air
2013-07-07 by Mitch Davis
... Some people live in very litigious societies. However well meaning you are, some asshole will always be looking for a reason to sue you, and scumbag
2013-07-07 by epa_iii
If you are going to insist on building a device with lamps that are a danger to view, then you should definitely consider the idea that this device may not
2013-07-07 by Jim
It s an interesting home chemistry demo project to make sodium carbonate from baking soda -- sodium bicarbonate. Get that box of Arm and Hammer out of the
2013-07-07 by James
... Drain cleaner, soap manufacturing, methamphetamine production and melting the flesh of your enemies... all popular uses for sodium hydroxide (lye). Sodium
2013-07-07 by Duane C. Johnson
... using ... I agree, the bath must be alkaline and a common and convenient alkaline bath is Sodium Hydroxide . I get mine at the local hardware store where
2013-07-07 by James
Also, here is a document with all my hints and tips for dry film usage: http://sirius.gogo.co.nz/dry-film-tips.pdf ... [Non-text portions of this message have
2013-07-07 by James
... Holy moley, WAY too much. 20 grams of washing soda (sodium carbonate) per litre is fine, if you are using 200g per litre then I m not surprised it s giving
2013-07-07 by Leon Heller
... I don t think that washing soda (sodium carbonate) will work, you sodium hydroxide. That s what I use - 2 teaspooons per litre. Leon -- Leon Heller G1HSM
2013-07-07 by Kerry Koppert
I am trying to produce a small PCB for a SMD pic16f628a-i/so using chinese blue dry film photoresist. The exposure seems to work fine using a bank of uv leds
2013-07-06 by brane2
... I already have two of those on cobbled up reflector. They are not as good as low pressure Hg, but they are not that much worse. And they work simply
2013-07-06 by Harvey White
... There are reasons why EPROM erasers have a kill switch on the lights when the enclosure is opened. You can seriously damage your sight with these lamps,
2013-07-06 by "Zoran A. Šćepanović"
... Watch your eyes, UVC is harmfull :-) -- Best Regards, Q Systems Zoran A. Šćepanović zastos@gmail.com Skype: zoran.a.scepanovic http://zastos.com +381 63
2013-07-06 by brane2
I ve just finished purchasing some of the material for our first non-improvised lamp. I plan to use Osram s bactericidal fluo lamp Puritec 15W:
2013-07-06 by "Zoran A. Šćepanović"
... I would suggest not to use the lamps that you specified. UVC is not the wavelength band that is the best solution for PCB exposure. Try to find lamps
2013-07-06 by arvidj01
... The UV LED s on eBay seem to come in two flavors: narrow angle, about 20 to 25 degrees wide angle, about 150 to 160 degrees It would seem like the wide
2013-07-06 by arvidj01
... Thanks for the responses. I was impressed by the think and tinker solution but was turned off by the expense of the lights and fixtures and the size. Based
2013-07-06 by Mitch Davis
... If the pins are 0.5mm or finer, you re better off not having solder mask. Have a look in section 3.7.2 of this doc:
2013-07-06 by cunningfellow
... I agree with Frank wholeheartedly https://www.thinktink.com/stack/volumes/voliii/equipment/uvlamp/uvlamp.htm
2013-07-06 by James
... For hobby purposes, this. If you use LEDs, just do a quick check that your led spacing and distance to your artwork from the leds does not introduce dead
2013-07-06 by Mike Wirth
Hi, folks, New member here (glad to find the group!) but long time electronics designer and fabricator. (Have my own metalworking shop, various chem lab
2013-07-06 by Frank Collingwood
It s an issue for extremely fine tracks. You can always use 4 inch drain pipe, cut in half along the longitude, and lined with mirror plastic, plus egg crate
2013-07-06 by cunningfellow
... If your only looking for 8/8 rules and have a good phototool in a vacuum frame then collimation is not an issue. I had one of those kinsten boxes that has
2013-07-06 by arvidj01
Having been given several flat bed scanners I am finally going to build an exposure box and was thinking about the light source. The boards could be as big as
2013-07-05 by Vicent Colomar Prats
Thank you for the link, I m also European, from Spain. I m interested in your cnc process. I just tried a 0.2mm v-shaped bit and managed to do a good job for
2013-07-05 by fred27murphy
It s the same one used in the Instructable but as I m in the UK I tracked down a European supplier. It s Dynamask 5000 and I ordered a roll from from
2013-07-05 by Vicent Colomar Prats
Can you tell us what kind of solder mask film have you used? Brand and model? Cheers. 2013/7/4 fred27murphy ... [Non-text portions of
2013-07-04 by fred27murphy
An old thread but I thought I d contribute something with my first post. I got one of these UV nail lamps to use for solder mask film - inspired by this:
2013-07-02 by jcarlosmor
Hello to Everybody, After a long quest I finally sourced and bought parts of a surplus Kepro BTE 202 machine. However, the spray bars are missing, so the
2013-07-02 by Homebrew_PCBs@yahoogroups.com
Monthly Reminder for Homebrew_PCBs list, please read: Messages and threads: Please do NOT start a new thread by replying to another message. Even if you change
2013-07-01 by Gustavo Villada
I use a soft rubber spoon that is used in pastry-making and remove all bubles between PCB and plastic wrap. now I must buy a new pair before my wife get enrage
2013-07-01 by Phil@Yahoo
Haven t tried that but I doubt it would make much difference. The coating has to be covered with either a protective sheet or the mask itself, and the material
2013-07-01 by James
... I cure paint with 80 leds, in 25 to 30 minutes. 100 UV leds is just a few bucks on ebay. Resist is done in 2m50s. Somebody else asked about wavelength, I
2013-07-01 by Kirk McLoren
that sucks remember you are unique. Just like the rest of us. ________________________________ From: cunningfellow To:
2013-07-01 by cunningfellow
... Phil, Have you tried using a silk screen too apply it? (A blank screen that has no diazo/pattern on it)
2013-07-01 by cunningfellow
... It will cost $1000+ to get as much UV light with LEDs as $50 worth of arc/fluro. If your just doing resist then you don t need much UV. If you are curing
2013-06-30 by Phil@Yahoo
None of the Chinese suppliers I ve used ever publish details like wavelengths or even instructions. I guess with the language barrier they figure if you don t
2013-06-30 by Kirk McLoren
I would buy LED light over tube if it works ________________________________ From: tda7000 To: Homebrew_PCBs@yahoogroups.com Sent:
2013-06-30 by tda7000
Different resist will probably be slightly different but around that should work fine. I am using standard power LEDs with a wavelength of 395~400nm and they
2013-06-30 by James
... Good question. I don t have a good answer for you. As I said in a previous post, I have found that cellophane as in cellophane gift bags work technically
2013-06-29 by Terry
Exactly what plastic are you using to cover the ink/paint?
2013-06-29 by Kirk McLoren
http://www.ebay.com/itm/High-Power-5w-uv-led-chip-395nm-Factory-price-ROHS-/221247492077?pt=LH_DefaultDomain_0&hash=item338360cfed will 395nm uv do it? What is
2013-06-29 by <n0tt1@...>
RE: the ink that is used for PCBs...does it have a long shelf life? It reminds me of the ink that is used to make silk-screens for tee shirts and the like.
2013-06-29 by Phil@Yahoo
One other thing to think about. Any bubbles in the ink will harden into surface imperfections, so you should smooth out any bubbles before exposing. Really
2013-06-29 by Gustavo Villada
... I test today and work fine, but I ll need to buy a couple of UV tubes since this winter is raining a lot :( [Non-text portions of this message have been