PCB making kit questions...

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b3groover

Well-known member
Joined
Jun 22, 2004
Messages
359
Location
Lansing, MI
Hi folks,

So I'm nervously going to venture into PCB making. I think I'm going to go with the MG Chemicals kits (http://www.mgchemicals.com/techsupport/photo_demo.html#10) as linked on Kev's Group DIY website.

The MG Chemicals site suggest you kit the Photofabrication Kit ($41.83 from Allied here in the states), the Exposure Kit ($32.12 from Allied) and the Etching Kit ($169.49). Now that's a lot of bread!

So here are my questions: The Exposure Kit looks like it consists of a flourescent light fixure and a plexiglass plate to hold the artwork to the PCB. I can get light fixtures and plexiglass at my hardware store for cheap. Do you just stick a UV (ie, blacklight) bulb in there and have at it? Maybe build a little lightbox?

Secondly, the important part of the etching process is (obviously) the right chemicals, heat, and agitation, right? Couldn't I just get a fish pump, a "coffee heater" and a decent plastic tank thing (or even glass... my bro works at a pet store)? Then it's just a matter of getting the right chemical (ferric chloride) right?

I know this might sound silly, but I just want to make sure I'm not missing anything. These kits seem awfully expensive for what they are.

Thanks!
 
how many boards do you plan to be etching?

I did a bunch in the past by just using press 'n peel, bought the etchant at radio shack, heated the container in boiling water for a bit, agitated the boards in a tubberware container and had boards. They were totally ghetto, but they worked for fuzzboxes and sounded as good as my point to point projects did. It was totally ghetto, but it also only cost about $20 total...

having gone through that, it would be cool to get a proper setup if I ever were to self etch again, but I wouldnt spend all that dough if I was only doing a few boards.

dave
 
Well, I'm doing just one for now, but I'd like to build some Green pre's and an SSL clone and the G9 eventually and maybe some more shit. So I think a proper setup is the way to go but those kits seem awfully expensive for what they are.
 
JPL cant have any environmental testing done on their property since all the shit they dump there is classified (true fact, amazing loophole, eh?) so I just dump it there... thats a long ass drive from nyc.

dave
 
Don't know if it's true, but I always heard that etchant isn't "that" bad for the environment. The copper that you remove is actually more harmful-that said, I flush it down the sink and let the water run for a while. Definately just build your own lightbox. I don't remember the link, but over at gyrafs site, they have a good link af a guy who built a light box. it took me an afternoon...

Joel
:guinness:
 
Do you just stick a UV (ie, blacklight) bulb in there and have at it?
I think what you want are shortwave UV tubes, not longwave 'blacklights'.

I've got a nice manufactured box I bought off ebay. Though I've never had to replace the tubes it apparently takes the fluorescent lights used in 'bug zappers' which apparently emit shortwave UV. Takes a fraction of the time to expose a board with these tubes than with ordinary fluorescent lamps.

Shortwave UV is not good for the eyes or skin (unless you enjoy looking at fake tans) so the box has a switch which doesn't allow the tubes to glow unless the lid is closed. Makes me wonder why bug zapper manufacturers don't warn you about the dangers if indeed the tubes are the same.
 
i've tried a number of times to print circuit boards via the laser printer, iron on method and it totally blows goats. after weeks of trying and trying i just bought a few boards from the guys on this forum( back when it was TT at RO) and they came out much nicer than anything i could have done on my own. now you can get the gerbers and have them made but they would of course be much more expensive than the gentlemen here sell them for. Pm Swedish Chef and Gustav for the boards, they both sell HIGH quality version of various boards you are looking for, for very good prices.
 
I try the laser copier setup also with no success then I bought an exposure
lamp and the chemicals and bingo. I mainly use it for PSU 's, I have
done Peter C's psu and misc others. It is a usefull system to have even
if it's only for PSU's. The lamp with bulb cost 34.00 cdn. So go to Lowes and home depot and price a fixture not too much lower and then find the right bulb. Best off with the kit. I microwave the chemical , heat it up in tupperware and drop the board in and swoosh it around. WEtchant can be used over again so just put it back in the bottle or get another bottle and put the used ecthant in that.
 
I think Press'n'Peel Blue ROCKS! I get great results with it. I use the laser printer at work, then iron and etch at home. Piece 'o' cake. So, I have absolutely no desire to try futzing around with a light box. To each his own... I guess. :cool:

~ Charlie
 
[quote author="mnats"]
I think what you want are shortwave UV tubes, not longwave 'blacklights'.

I've got a nice manufactured box I bought off ebay. Though I've never had to replace the tubes it apparently takes the fluorescent lights used in 'bug zappers' which apparently emit shortwave UV. Takes a fraction of the time to expose a board with these tubes than with ordinary fluorescent lamps.[/quote]

Can anyone confirm this? I need bug-zappin' tubes? COOL! :)
 
Here is the exact bulb that came in the MG kit I bought(read the part number off the bulb, plugged into google, and whala!). Just a daylight:

http://www.damarww.com/product.asp?sub=34&dep=T8%20Medium%20BiPin&prod=00588D

I've gotten excellent results with my pcb's.

Exposure time: 10 minutes

Use an aquarium heater in the etchant, make sure it's good and hot before you start etching ( it will etch way faster if you do this). got my heaters off ebay for like $5.

make sure that your artwork is firmly pressed down onto the board, any distance between the artwork and the board will cause your board to turn out fuzzy.

ju
 
[quote author="fum"]Here is the exact bulb that came in the MG kit I bought(read the part number off the bulb, plugged into google, and whala!). Just a daylight:

http://www.damarww.com/product.asp?sub=34&dep=T8%20Medium%20BiPin&prod=00588D

I've gotten excellent results with my pcb's.

Exposure time: 10 minutes[/quote]
The fluorescent tubes in my exposure box are Hitachi F8T5/BL. Looks like they refer to them as 'blacklights' too. I'd have to check if they have the same effect on a Jimi Hendrix poster as the normal dark purplish blacklights. They give a bright pale violet glow that looks a little greenish from the leak around the seal on my box. Could be the foam glowing though.

Exposure time: 60-90 seconds. I think this varies a bit with the actual photoresist used - but you get the idea.

I used to use a normal daylight bulb too but it's hard not to get distracted when waiting for a 10 minute exposure, head off to do something else, then come back when you discover you overexposed the board.
 
Here is my setup:
easy to make lite table uses normal 18 inch black light head shop bulbs.
light_table_1.jpg


I used 3/16 inch glass, cost about 12 bucks.

light_table_2.jpg


Use a big weight for fine pitch transfers:

weight_1.jpg


40 dollar tank comes with heater, which will break shortly, and a air pump.
Circuit Specialties in the U.S.
Use tupperware for developer. I use sodium metasilicate.
I use Sodium Persulfate or Ammonium Persulfate for etching.
Also, MG 4 by 6 boards, fiberglass only!
I tried everything else, and this was my final solution.

chemicals_1.jpg


Works for me. cj :sam:

I just drink the used etching solution. Keeps the lower GI clean. :grin:
 
You know whats funny?
I can't drink blue Gatorade anymore!
And it was one of my favorite flavors, darn it.
It was after I used an empty Gatorade bottle for the etchant when I realized how close it looks to the actual product!
Call me paranoid, but I ain't drinking blue Gatorade anymore! You never know!
Be sure to mark your bottles with a poison symbol or something!

poison.jpg

:sam:
 
One more thing. After tonights etching, I don't recommend the MG boards. Very poor quality control IMO. The boards I got had edge bleed, and flaws in places.

there's nothing like etching a board, only to find the board had a flaw, and you end up with a big line through the traces :evil:

I've had good results with fotoboard, and will be buying some more cards soon.

Who knows, maybe I just got a bum set. Still pisses me off =)

ju
 
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