BasicMicro - Forums

I want to try making PCBs at home. I have the MG Chemicals kit http://www.mgchemicals.com/products/416k.html

In the instructions, it suggests a 15W daylight fluorescent bulb for exposing their boards..On the web, I have found suggestions ranging from a 100 watt incandescent bulb to a UV bulb in the 356 nm range of light.....

So, since CFL are so common now, can I use a compact fluorescent bulb in a lamp holder? Boards will be small at this point and I realize that I will need to try to make light intensity fairly even over the board so may move to tube bulb later but till I figure things out, does a compact fluorescent emit light in the proper range?

Someone suggested doing test strips...makes sense but necessary?

Do I have to have a UV bulb? Does one type ensure better results over another? I can see myself building a small light box in the future. I have a few small tube fixtures around the house that I could steal (when my wife is not looking) to expose the boards for now too if a tube is different than a CFL..?

More specifically, I just realized I have one of those magnifying lamps on the bench. It has a circular fluorescent tube in it, a FCL22/T15 22w. Work? Pretty convenient if the light is in the right nm range..

Hi. Always good to see another enthusiast looking to roll his own boards.

The 22W bulb in your magnifier should work just fine. Hell, you can expose this on a window sill in bright sun light, but the exact exposure time is an unknown.
Funny thing is, they want you to produce the artwork on a transparency to make the board from. You might want to check out the iron-on transfer method and skip the first chemicals. There are papers that you print on using a laser printer. You then use a household iron to transfer the toner to a standard copperclad board (read: much less cost/trouble) and skip the developer and fixative. That's two less chemicals you have to worry about spilling in the kitchen and finding a way to dispose of legally. (Yeah, pour it down the drain and flush it down with copious amounts of water. If you fail to do this properly, the drains rot out...). Of course you still have to etch the board.

There are several DIY (Do It Yourself) board making forums out there. Consider finding articles/threads on the subject. There are always several considerations to look into.
I myself went out last year and downloaded one of those free board design programs that let the user do the schematic, then lay out the board components. If you use their pre-defined board sizes, you can make three small boards for less than $60. IIRC, that includes soldermask, plated through holes, silkscreen... basicaly, you get professional looking boards to work with! But these get expensive damn quick. If you want to produce "proofing" boards, you can have the boards made without soldermask or silkscreen. You have to be REALLY careful when you solder the finished boards up, to avoid solder shorts.

Feel free to email me through the forums if you want more advice or help.
Take care.

_________________
kenjj
http://blog.basicmicro.com/
http://kjennejohn.wordpress.com/

Hey Ken

Thanks for the reply. I did up a test board a couple of nights ago and it turned out very well, I think for a first time board...see photo attached. The light did work well for exposure as well as convenience, simply lowering it down to the workbench to expose the board, through a transparency and glass plate. The board was tiny, 1 1-2x3/4, . Exposure time for a distance of 4" to board, for those stumbling across this thread, was about 6 minutes and etching, (cold at about 70 F) took about 15 minutes. I forgot to warm the etchant up, as the instructions emphasized. Traces look OK, actually very good, but they were just various sizes of text to see how it turned it out....I really did not expect the first board to turn out.. I think I will venture into a real board today or tomorrow so can report back later.
The light source is similar to this one

http://www.amazon.com/dp/B004GBAS0Q/ref ... B004GBAS0Q

As for the software, I have started and stopped several times over the last many many years, experimenting with various packages but have finally settled into one, sounds like the same one you use (not sure if you want it named here or not). It works great and if I get into something that I need production runs, then I will certainly use that company. I have been making my own components layouts and I must say, it works well! The problem with it is that every time I open the file up, I start moving stuff or changing traces, or making more components according to my stock of old parts that are not in the library or... .... fun program to use.

Recently, I have seen postings on the Laser Printer method and watched some You tube videos on it. It too, looks good, but I had already purchased this photo kit and extra boards so will use up these materials first. I also do not have a laser printer so that would be another purchase or I suppose I could print it on paper then take it to a copy shop with gloss paper? I have some non-sensitized boards so perhaps I will give it a whirl too. I could only locate laser transparencies locally and the ink takes a long time to dry but the good thing is that when you are done with the board or realize a mistake, simply give it a wipe with a damp cloth and reuse the transparency.

I now made up a jig for cutting the boards. I cut this one using a blade and several scores but it still seemed to require a lot of flexing (not enough scores?) of the board to snap it off and I feel this will affect the adhesion of the copper to the glass so I think cutting boards will be better. Have not tried the jig yet but will submit a photo later. It is still in the shop (woodshop) and needs sanding and finishing.

Cheers,

Here is the board. Looks like I may have to doctor a couple of traces. I heated the etchant this time but it took almost 25 minutes. I think too long as it looks like a couple of small flaws in the traces.

We will assemble and that will be the test....

It looks very nice for a first attempt. Maybe I'll have YOU make my boards...

Yes, there are several programs out there for board design. There are even two in the public domain, one for schematics, the other for board lay out. The good thing about them is, the final design can be submitted to board fabricators for cheap production. Then again, the guys offering free design packages will (but not all?) do the conversion to industry standard files for a fee, usually $60 or so.
Have fun with it!

_________________
kenjj
http://blog.basicmicro.com/
http://kjennejohn.wordpress.com/