Need advice on making custom circuitboards

Tumbleweed

Hey All,
A long, long, LONG time ago I made some circuit boards in high school using graph paper, some little black tape, a jug of noxious chemicals, and steady hands.

I'd like to think that the technology has improved since then for people doing at home prototyping and circuit board designs.

Can anyone point me to some software to design circuit boards?

Thanks,
Lance

SailerMan

Right now I'm using Dip Trace... Check it out it's nice. http://www.diptrace.com/

Design a schematic and then just dump it into the PCB Design section of Diptrace The Auto route or manually route.

I'm using a laser printer on a Positive Sensitized board and developing them like a film process and etching with Ferric Chloride.

I was doing the Toner Transfer method, but it's a pain to me.

Tumbleweed

SWEET! Thank you!

crgwbr

www.pulsar.gs

Great Toner Transfer supplies, not hard at all. For design, I use ExpressPCB's software; then print out the layout on Pulsar paper and iron on. Then just dip the board in acid (I make my own with 2 parts 3% Hydrogen peroxide and 1 part Muratic Acid. It many times cheaper than buying Echant and it works better too).

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NerdMaster
For
Life

Javalin

www.expresspcb.com

metron9

I am going to give these guys a try. 155sq inches for 100 bucks free step and repeat and V scoring. Production quantitys in the 12 cents per sq inch.

From a post on avrfreaks this really looks good.

http://goldphoenixpcb.biz/




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Think Inside the box first and if that doesn't work..
Re-arrange what's inside the box then...
Think outside the BOX!

Paul Baker

If you dont need 100 or 155 in²· boards, www.batchpcb.com takes smaller orders ($10 per order + $2.50/in²) and panelized your boards with other people's and sends it to Gold Phoenix. Obviously more expensive per sq in than dealing with Gold Phoenix directly, but you'll save a ton of money on small projects.


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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

SailerMan

OK I'm,·making the boards myself because I'm a geek and love to DIM... Do-It-Myself.

I have the board...It's etched, now I want to put a "Silk Screen" what is the best way to achieve this and how do I make them green with the finished look. Whats the best way to do Vias.

Thanks,

Eric

Paul Baker

On the first two points, you don't. The amount of money and time involved you'd be spending at least $50/ sq in unless you want to go into mass production. Vias are also a pain, requiring at bare minimum a drill press and best suited for a CNC table. Thats why so many of us try to point people to using professional services, you will spend alot more money doing it yourself (once you include the cost of tools and your time) as compared with the large discount houses. The reason people used to make thier own boards was because the program required to do layout cost $$$ and producing the boards professionally cost $$$. Now you have your choice of several free software suites, and board production is much cheaper than you could ever do on your own and much better looking.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

Phil Pilgrim (PhiPi)

I'll second everything Paul says. I'm a do-it-myselfer, too. But I draw the line on etching my own circuit boards — even with a CAM mill in my shop to drill them! It's JUST. NOT. WORTH. THE. HASSLE! PERIOD. I used to do it, fool that I was, and still have the stains on my counter top from the etchant and rust on my tools from the fumes to prove it. Having them done professionally is cheap and you get plated though-holes thrown in for no extra charge. Go to Alberta Printed Circuits. If I can't make a believer of you, they will!

-Phil

SailerMan

Oh I totally agree and I acknowledge all of those point especially the rust!! hahahah.

I really want to have my boards done professionally, but I don't think I'm to that point.. I am working on a Dual motor controller yeah I know.. Reinventing the wheel.. But it's been a lot of fun. I've etched about 3 Boards and am ready to do my 4th.. All have worked to my expectation, but I've added little things as I've gone.. LEDs, Jumpers and Headers. I originally didn't think about until I started using my first prototype. After my 4th board is etched populated and tested I am going to get them done professionally. But not quite yet. It's harder to prototype with SMT componenets. Which is what I've been using a lot of lately.

Thanks,
ERic

T Chap

Making homemade boards is fun for about 2 times, then after you chase down a problem for 5 hours it becomes less fun. Trying to fill vias by whatever means is not fun, you can run wire and solder each side, but then that gets really old. You can do a method from LPFK that uses a silver based paste, you rig up a vacuum table, drill holes in the pcb with a process, squeegie the paste, then ruin a number of them with heat by soldering. I spent countless hours trying that method, only to spend a fortune on the paste, and many hours trying to find out why the board doesn't work. Sunstone.com(company behind PCBexpress) will have boards at your door in 2 or 3 days, yes pricey, but think of the hours and mess doing your own boards, the yellow or blue stains depending on your solution, the watsted time in solving the problems. I mastered the process of PCB milling/drilling since I have machines. Eagle puts out a Gcode for milling and drilling that is effortless, yet, nothing but hassles because there will be problems. Every angle I have covered for homemade boards, and I can do them great, but trust this advice: life is too short.

Regarding SMT being harder, I disagree, I don't touch DIP parts any longer except connetors, caps, etc. I came up with a very cool system to create a stencil with mylar that you cut on a laser, stretch the mylar over the board on a rigged up stencil printer, squeegie the paste(1 min), place the parts(5 -10 min), oven for 5 minutes and done.

Post Edited (originator) : 2/2/2007 1:07:50 AM GMT

SailerMan

I didn't mean using SMT components is hard, I mean proto typing with them is hard.

Anyhow this is going is circles..

I Printed my layouts on Transparencies... Expose a board with a bright light for 2 mins etch- 5mins with the Sponge and Rub method and Drill 1 Min as most of my board is SMT... It takes me all of 10-15 mins to make a ready to populate board...Most of the time is preparing (Chemicals and Stuff) The good thing is that once I have the transparency I can mock up another one quickly.

No I don't want to do this forever but it's what I've got for now. I will use one of those PCB houses once I have a working board. Trouble shooting a board is not a problem.. Soldering the SX-48 by hand is simple.... I use Mainly 805 sized dicrete components a tad bit easier that 603. All I was asking was how to coat the board once I'm Done so it doesn't corrode.

Thanks again for all the insight.

Regards,
Eric

Phil Pilgrim (PhiPi)

Eric,

Once everything is soldered on and tested, clean the flux off with 99% isopropyl alcohol and a toothbrush. Then you can apply an aerosol conformal coat. My favorite is Tech-Spray's Fine-L-Coat AR, from Mouser. It's an acrylic formulation that dries hard. (Some conformal coatngs stay soft forever, but make rework easier.) You will have to protect your connectors and switches first with low-tack masking tape or removeable latex goo. Then give the board a generous coating from all directions, and let it dry.

-Phil

PJAllen

SailerMan said...
All I was asking was how to coat the board once I'm Done so it doesn't corrode.

The most important thing to do is thoroughly clean the board (wash off all contaminants) otherwise it's like painting over rust.· Many coatings are available -- look for Humi-Seal (it can be applied with a paint brush.)

SailerMan

Thanks guys.... Now should I use this stuff called tin-it first or is it unnecessary.

Eric

Paul Baker

Sorry Eric, I thought you were trying to make your boards look like the professional guys do. Yeah there are coatings which will protect your boards from corrosion. And take from someone who has handmade silkscreen T-shirts, you dont want to mess with it. Painting the stencil for a star with the words "YOU ARE HERE" in 1.5" block·letters on top of the star took about 8 hours to do by hand. I wouldn't even contemplate creating a stencil for letters the size used on circuit boards.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

John R.

Eric;

Check out the Pulsar site. Besides the toner transfer stuff for the traces, they have some toner transfer for the "silk screen" and they also reference a supplier for some "silver plating" supplies.

In the past, long ago, I made some boards by hand (and may be doing so again soon), and found that if I didn't do "some" type of plating (tin or silver), the copper was very quick to oxidize, and besides looking like he--, er heck, any soldering attempts after oxidation were a pain in the neck.

Other than that, I have no idea of the impact on circuit performance.

The "green" color is normally from the solder mask. I'm not aware of any DIM/DIY products for this, but that means utterly nothing in this case. I haven't even really started to look.

If anyone knows of a _functional_ (as opposed to a purely aesthetic "green" coating) "DIY" solder mask, I'd be interesting in knowing about it.

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John R.
Link to My Nomad Build Log

Bean

SailerMan said...

Thanks guys.... Now should I use this stuff called tin-it first or is it unnecessary.

Eric

I have used Tin-it, but it's a pain to use. It must be heated, and it doesn't do a great job.

Now I use "Liquid Tin" from MG Chemical. It works great, just dip your board in and it's tinned. But be careful, it's VERY corrosive. DO NOT GET ANY ON YOUR SKIN.

Bean.



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John R.

What's the fun of playing with this stuff if you can't get it on you? (Just kidding.)

For those not familiar with the stuff were talking about (etchants, plating solutions, etc.) they tend to be caustic/corrosive/poisonous, etc. and should be handled with care and appropriate PPE (Personal Protective Equipment), meaing rubber gloves at a minumum.

This is also good stuff to keep away from clothes, any type of eating/food preparation surface (i.e. don't do this in the kitchen) and anything else you care about keeping looking the way it looks before hand. At a minimum, you'll give something a very good, very permanent stain.

As noted above, even the fumes from the etchant can/will have an adverse affect on tools and other metal items.

Now, all that said, this isn't a "don't do try at home" speach, just a "use your head, and understand what you're dealing with" speach.

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John R.
Link to My Nomad Build Log

T Chap

Sailor, sorry for the unsolicited homebrew pcb deterant.

I found that for FerCloride, Ajax did the best job to clean up.