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I don’t care about spacing, I solder them straight to the PCB and smaller is better. 0.3” is fine by me.
If I want them pluggable I’ll solder some headers in first.
I’m avoid etching fine pitch stuff, these rest I don’t care about much.
I’d like it if I could get castellated (half-moon) ones. Could get someone like DirtyPCBs to do a batch I suppose. They don’t v-score though.
Tony
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Saturday, 10 December 2016 5:33 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] IS GREEN TRF the same thing as Heat Transfer Foil Pigment Laser Toner Foil
Tony,
be very careful about those cheap adapters you mention. Your idea is the same as mine and I have just spent the last 6 to 8 weeks buying smt to dip adapters on epay only to find out that the soic14 to dip 14, soic16 to dip16, soic18 to dip18, soic20 to dip20, soic22 to dip22, and soic24 to dip 24 are misadvertising their product! They all are tssop and sop layouts too. What they fail to tell you is that they are all 0.6" row spacing. Standard through hole ic sockets us 0.3" spacing! The 0.6" spacing is what is used for old style 24, 28, and 40 pin eproms and cpu's and zif sockets used in programmers. I have yet to buy one on epay that fit into a standard through hole ic socket. The one exception appears to be the 8 pin version and they turn the smt part so it goes across the board where the rows go down the side of the board but the smt ic's I want to use are not 8 pin but are 14, 16, 18, 20, 22, and 24 pin ic's. It is cheaper for me to buy the smt part than it is to buy the through hole part if it is still being made. I had hope to just use smt parts but that has turned out to be a false dream.
I had a thread running on QRP-Tech forum about that. Someone pointed out one outfit that LOOKED like they made some smt14 to dip14 adapters but someone else suggested that they also did not quite fit. They are sold by Mouser too but the 5"x7" board with adapters was $50 and that is way too expensive for me! So just be aware that you might be sorely disappointed as I was. I am currently waiting for 2 adapters to arrive from China that claimed they would do it but instead of 5 for a buck they were 2 bucks each and may still be too wide to fit standard ic sockets. Also watch the vendor closely as I have heard of others where the spacing was some weird row spacing like 0.5" rather than 0.6 inches. When I have tried to tell the vendors that I bought from that they misrepresented their product and it is not a STANDARD dip14 socket they have some vague excuse. I understand that it would not be practical to have sop/tssop/soic adapters on the same board but I do not consider 0.6 inch spacing to fit into standard ic sockets!
AncelB talked about making some smt to dip adapters available but I have not heard him mention it since we talked about it so I don't know how that is going.
Personally I would think that the dual row could still fit if it was underneath or on the bottom layer and did not come through the board (making the dual header row smt) and the ic itself on the top layer. It would not be practical to have more than one type of ic (soic, sop, tssop) on a board so the sop/tssop/soic adapters would not work in my example.
Good luck.
Jim Pruitt
On Fri, Dec 9, 2016 at 8:35 PM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
Probably the best hobbyist method these days is to modify a cheap printer to do direct printing as pioneered by Mark Lerman (spelling?). That didn’t seem possible but he proved us wrong. The only consumable is acetone which other toner methods needs anyway.
Laser & paint might be even easier but I’ve yet to try it.
I’ve been finding for fine pitch work it’s easier to buy those adapters, solder the SMD part to that and them soldering that to the main board is easier. Packs of those are pretty cheap these days. You convert the SMD into through hole so the main board is simpler. As usual YMMV.
Tony
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 Heat Transfer Foil Pigment Laser Toner Foil
The goal was to figure out if the touchup pen can be omitted from the process.
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 of TRF per PCB.
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 a pen won’t already.
The foil will probably lessen the edge quality (ragged edges) and possibly spread the traces when run through the laminator again.
I’m a bit dubious about the return on investment there. I remember this stuff from years ago.
Anyway, no harm trying. Less harm if it’s someone else trying it!
Tony
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 Heat Transfer Foil Pigment Laser Toner Foil
Because the toner is not 100 percent etch resistant.
The toner leaks. Not a lot, a pin hole here and there.. a tracing gap ..... imperfections.
The toner transfer isn't always perfect for me..... close... real close 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 a sharpie 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 of transfer method
that is known to STICK TO TONER quite well.
I have not used it yet but intend to learn if the cheap 100 foot craft 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 not manufacturing anythign to sell.
I'm just documenting what works for me to share with the kids....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 without screwing them up.
So if TRF foils do this sealant task then that would be real nice to learn.
And yes... I had that same thought about foil... metal... etching......
so I bought the notsoshiny stuff to play with...thinking its just the pigment 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 are subjected to high heat and pressure, the color permanently fuse to just the toner image.
The interesting thing about toner (from a laser printer or photo-copier) is that it is madeup of about 55% pulverized plastic. So, by covering a toner printed image previously transferred to the copper board, and applying heat & pressure to it, the foil encapsulate the toner. In effect, the black toner turns either Green or White. We use these two foils for two different purposes.
GreenTRF is used to seal the toner "circuit image" after it has been transferred to the circuit board.
Toner is a very porous material. If left alone and the board was etched, you'd wind up with pitted surfaces or even hairline breaks from cracks that were too small to see with the naked eye.
GreenTRF solves this problem by completely encapsulating the toner image in one easy step. An absolute "must have" for producing quality boards.
Film for colorizing and sealing black toner used as an "etch resist".
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 a resist?
Shiny though!
I wonder if it’s conductive…
Tony
I see there is this:
Heat Transfer Foil Pigment Laser Toner Foil 8"x100' Roll OR 4"x100' Roll US Made
so
I bought the 4 inch X 100 foot roll for $15 just to try it out.
Instructions all over the YOUTUBE say how to apply it to toner artwork with an iron or laminator
so this looks to me like it might work for etching.
On 12/09/2016 10:56 AM, Rob roomberg@... [Homebrew_PCBs] wrote:
I tried nail polish. I got what looked like crackle paint hairline webs in the final copper traces.....
looked almost like ice crystals.... seemed to have shrunk when it dried and then allowed acid to etch where it shrunk.
Considering all nail polish is not created equal there may be a better 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 to warrant experimenting with it.
On 12/09/2016 04:25 AM, Kevin Byrne kbyrne10@... [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 was cheep nail polish a cheep artist brush and direct etch. Nail polish remover to remove nail polish after acid bath. That could be done cheep by just going to dollar store for supplies and no more pits for your art work on copper. Kevin