Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Yes, that is the correct spelling. And, yes, the direct printing is muchfaster and easier, with 6 mil traces usually achievable.

For anyone reluctant to try smt, I would encourage you to give it a try.SOIC and 0805 parts are EXTREMELY easy to use and once you get used tothem, are MUCH faster to solder. I routinely do TQFP64 Atmel mcus byhand,  and get a lot of pleasure from being able to do so, but theycan be a bit dicey.  There are lots of tutorials out there on usingsmt, and all it takes is a little practice.

For more complex pcbs I use a hotplate and solder paste that I usuallyhand apply using a small (1cc) syringe and a 24 gauge catheter.


Mark




At 01:04 AM 12/10/2016, you wrote:

PANTUM here nowwaiting to be hacked.

SOIC is definitely doable.
This is a PIC16F629
http://www.learnmorsecode.com/laminator/etch/testetch5070.jpg
http://www.learnmorsecode.com/laminator/etch/testetch5077.jpg
http://www.learnmorsecode.com/laminator/etch/index.html

I sort of think of SOIC as a novelty.
Nothing in my hobby electronics world mandates SOIC.
Nothing SOIC has replaced anything DIP here because DIP is obsolete andunavailable.

I only show and tell SMT to educate the kids..... and intrigue the adultswith
007 James Bond transmitters.... KNIGHTSMITE in a mint can.



On 12/09/2016 11:35 PM, 'Tony Smith'ajsmith1968@...[Homebrew_PCBs] wrote:

 

Probably the best hobbyist method these days is to modify a cheap printerto do direct printing as pioneered by Mark Lerman (spelling?). That didn’t seem possible but he proved us wrong.  The onlyconsumable is acetone which other toner methods needs anyway.

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Laser & paint might be even easier but I’ve yet to try it.

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I’ve been finding for fine pitch work it’s easier to buy thoseadapters, solder the SMD part to that and them soldering that to the mainboard is easier.  Packs of those are pretty cheap thesedays.  You convert the SMD into through hole so the main board issimpler.  As usual YMMV.

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Tony

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From:Homebrew_PCBs@yahoogroups.com[mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Saturday, 10 December 2016 2:59 PM
To:Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] IS GREEN TRF the same thing as HeatTransfer Foil Pigment Laser Toner Foil

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The goal was to figure out if the touchup pen can be omitted from theprocess.
Its hard to see to do the touchup.

And as far as return on investment goes......
IF it works with the craft TRF then that works out to less than a dime ofTRF per PCB.
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On 12/09/2016 10:18 PM, 'Tony Smith'ajsmith1968@...[Homebrew_PCBs] wrote:

 

I don’t think the foil is going to add much that touching up with apen won’t already.

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The foil will probably lessen the edge quality (ragged edges) andpossibly spread the traces when run through the laminator again.

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I’m a bit dubious about the return on investment there.  Iremember this stuff from years ago.

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Anyway, no harm trying.  Less harm if it’s someone elsetrying it!

Â

Tony

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From:Homebrew_PCBs@yahoogroups.com[mailto:Homebrew_PCBs@yahoogroups.com]

Sent: Saturday, 10 December 2016 1:53 PM

To:Homebrew_PCBs@yahoogroups.com

Subject: Re: [Homebrew_PCBs] IS GREEN TRF the same thing as HeatTransfer Foil Pigment Laser Toner Foil

Â

Because the toner is not 100 percent etch resistant.

The toner leaks. Not a lot,  a pin hole here and there.. atracing gap ..... imperfections.

The toner transfer isn't always perfect for me..... close... realclose to perfection.....

but not perfect every time.

http://www.learnmorsecode.com/laminator/pic/PIC16F628PROTO8d.jpg

So I have taken up the procedure of going over the toner with asharpie permanent marker...

then found EDDING 404 MUCH better than the sharpie.....

and getting excellent etchings:

http://www.learnmorsecode.com/pic/line/IMG_5156a.JPG

So now we have this problem solved by an arts and crafts type oftransfer method

that is known to STICK TO TONER quite well.

I have not used it yet but intend to learn if the cheap 100 footcraft toner reactive foil will

deposit an acid resistent layer.

It would save me the task of tracing the toner.

One thing to note about all this testing on my stuff is that I'm notmanufacturing anythign to sell.

I'm just documenting what works for me to share with thekids....scouts....newbies......

and I'm not making real tiny SMT projects.....

much of my traces are 1/8th inch and nothing real critical here.

 BUT

its nice to learn how this CAN be done smaller.....

and I don't think its possible to hand trace SMT toner traces withoutscrewing them up.

So if TRF foils do this sealant task then that would be real nice tolearn.

And yes... I had that same thought about foil... metal...etching......

so I bought the notsoshiny stuff to play with...thinking its just thepigment we want to stick to the toner.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

FROM:https://www.circuitspecialists.com/pcb-trf-green.html

This Green foil has a special adhesive coating ("sizing")applied underneath the pigment color. When the foil and toner image aresubjected to high heat and pressure, the color permanently fuse to justthe toner image.

The interesting thing about toner (from a laser printer orphoto-copier) is that it is madeup of about 55% pulverized plastic. So,by covering a toner printed image previously transferred to the copperboard, and applying heat & pressure to it, the foil encapsulate thetoner. In effect, the black toner turns either Green or White. We usethese two foils for two different purposes.

GreenTRF is used to seal the toner "circuit image" after ithas been transferred to the circuit board.

Toner is a very porous material. If left alone and the board wasetched, you'd wind up with pitted surfaces or even hairline breaks fromcracks that were too small to see with the naked eye.

GreenTRF solves this problem by completely encapsulating the tonerimage in one easy step. An absolute "must have" for producingquality boards.

Film for colorizing and sealing black toner used as an "etchresist".

8" wide, 15 feet long.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

On 12/09/2016 09:06 PM, 'Tony Smith'ajsmith1968@...[Homebrew_PCBs] wrote:

 

Why bother putting foil over toner if the toner already works as aresist?

Â

Shiny though!

Â

I wonder if it’s conductive…

Â

Tony

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I see there is this:

Heat Transfer Foil Pigment Laser Toner Foil 8"x100' Roll OR4"x100' Roll US Made

so

I bought the 4 inch X 100 foot roll for $15  just to try itout.

Instructions all over the YOUTUBE say how to apply it to tonerartwork with an iron or laminator

so this looks to me like it might work for etching.

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On 12/09/2016 10:56 AM, Robroomberg@... [Homebrew_PCBs]wrote:

 

I tried nail polish. I got what looked like crackle paint hairlinewebs in the final copper traces.....

looked almost like ice crystals.... seemed to have shrunk when itdried and then allowed acid to etch where it shrunk.

Considering all nail polish is not created equal there may be abetter etch resist nail polish. I am not the

guy to test all of them.

At $9 ....seems the price of 15 feet of GREEN TRF is cheep enough towarrant experimenting with it.

Â

On 12/09/2016 04:25 AM, Kevin Byrnekbyrne10@...[Homebrew_PCBs] wrote:

 

Yea but my Green TRF gets perfect copper traces no pits, no joke.Green trf under pieces of steel after? Would it work? My old way wascheep nail polish a cheep artist brush and direct etch. Nail polishremover to remove nail polish after acid bath. That could be done cheepby just going to dollar store for supplies and no more pits for your artwork on copper. Kevin

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