Homebrew_PCBs

I'm going to need a few double-sided SMT prototype boards in a few months, with a more constant need for prototype boards after that. Maybe I'm lucky, but I have a choice of methods. In addition to a laser printer with toner transfer paper, I've got a small CNC machine I could repurpose as a PCB Mill, a few small vinyl cutters (Which I've never used, but would like to), and an old flatbed pen plotter that I actually used 15 years ago to make a carrier board for a small SMT connector. I'm looking for opinions for the best/easiest/quickest/most reliable method. I wouldn't mind getting a cheap inkjet and try the direct-print method, or hacking up an old laser printer for direct print toner. Milling sounds great in theory, and replacing the bit with a drill means precision drilled holes as a bonus, but the mess and noise is a bit of a turnoff. Transfer paper with a Laser printer worked in the past, but aligning the second side is always hit and miss. I never tried inkjet, and it sounds really interesting, but it looks like an almost-solution, with the ink not really resisting the etchant without extra work. I just came across the vinyl cutter method, where you cut the traces out in vinyl and transfer them to the PCB to etch, and it sounds interesting, but not sure how easy or reliable it is. I'm leaning towards using the plotter, as it seems there will be a little less 'playing' with ink that works, and I've successfully used it to make some pretty fine traces in the past.
While I don't mind etching, I'm looking for as close to "hit print, get a reliable and cheap board spit out' kind of thing, with little setup or cleanup.. Has anyone used any/all of these methods? What was your favorite?
Thanks!

On 08 Jun 2016 12:28:37 -0700, you wrote:

>I'm going to need a few double-sided SMT prototype boards in a few months, with a more constant need for prototype boards after that. Maybe I'm lucky, but I have a choice of methods. In addition to a laser printer with toner transfer paper, I've got a small CNC machine I could repurpose as a PCB Mill, a few small vinyl cutters (Which I've never used, but would like to), and an old flatbed pen plotter that I actually used 15 years ago to make a carrier board for a small SMT connector. I'm looking for opinions for the best/easiest/quickest/most reliable method.

you can do best/easiest/quickest/most reliable, pick two. (seriously,
every method has a tradeoff).

>I wouldn't mind getting a cheap inkjet and try the direct-print method, or hacking up an old laser printer for direct print toner.

Cheap inkjet requires a specific ink for the resist from what I know.
Not sure how many use it currently.

Direct print from a laser printer is essentially toner transfer done
in one step. I have yet to try it, but it does sound good. Laser
path is critical, though.

>Milling sounds great in theory, and replacing the bit with a drill means precision drilled holes as a bonus, but the mess and noise is a bit of a turnoff.

It is the least hands-on method, the major expense is the bits.
There's a limit to what kind of boards you can do, based mostly on the
bit diameter. Look into PCBGCODE.

>Transfer paper with a Laser printer worked in the past, but aligning the second side is always hit and miss. I never tried inkjet, and it sounds
>really interesting, but it looks like an almost-solution, with the ink not really resisting the etchant without extra work.

I more or less solved the two sided registration problem by making the
top and bottom from separate single sided sheets of pcb material and
epoxying them together. You will need a very accurate method of
drilling the registration holes. I built an upside-down drill press
to do this and that solves the problem.

>I just came across the vinyl cutter method, where you cut the traces out in vinyl and transfer them to the PCB to etch, and it sounds interesting, but not sure how easy or reliable it is.

Or how accurate.

>I'm leaning towards using the plotter, as it seems there will be a little less 'playing' with ink that works, and I've successfully used it to make some pretty fine traces in the past.

The ink, IIRC, is critical.

>While I don't mind etching, I'm looking for as close to "hit print, get a reliable and cheap board spit out' kind of thing, with little setup or cleanup.. Has anyone used any/all of these methods? What was your favorite?
>Thanks!

If you have the CNC capability, I'd be very tempted to use it. Depends
on the qualities of the pc board you're trying to make.

Otherwise, laser toner transfer, however done, is possibly your second
method.

Photoetching (which you have not mentioned) is perhaps the best way
and closest to commercial, but you have to have the sensitized board
or figure out how to do your own.

Harvey

>

On 6/8/2016 3:28 PM, rchadwick7@... [Homebrew_PCBs] wrote:

>
> I'm going to need a few double-sided SMT prototype boards in a few
> months, with a more constant need for prototype boards after that.
> Maybe I'm lucky, but I have a choice of methods. In addition to a
> laser printer with toner transfer paper, I've got a small CNC machine
> I could repurpose as a PCB Mill, a few small vinyl cutters (Which I've
> never used, but would like to), and an old flatbed pen plotter that I
> actually used 15 years ago to make a carrier board for a small SMT
> connector. I'm looking for opinions for the best/easiest/quickest/most
> reliable method. I wouldn't mind getting a cheap inkjet and try the
> direct-print method, or hacking up an old laser printer for direct
> print toner. Milling sounds great in theory, and replacing the bit
> with a drill means precision drilled holes as a bonus, but the mess
> and noise is a bit of a turnoff. Transfer paper with a Laser printer
> worked in the past, but aligning the second side is always hit and
> miss. I never tried inkjet, and it sounds really interesting, but it
> looks like an almost-solution, with the ink not really resisting the
> etchant without extra work. I just came across the vinyl cutter
> method, where you cut the traces out in vinyl and transfer them to the
> PCB to etch, and it sounds interesting, but not sure how easy or
> reliable it is. I'm leaning towards using the plotter, as it seems
> there will be a little less 'playing' with ink that works, and I've
> successfully used it to make some pretty fine traces in the past.
> While I don't mind etching, I'm looking for as close to "hit print,
> get a reliable and cheap board spit out' kind of thing, with little
> setup or cleanup.. Has anyone used any/all of these methods? What was
> your favorite?
>

Hello--

I'm envious of your collection of tools that could produce boards via
various methods!

For fastest and likely most error-free SMT-intensive PC board
fabrication, I'd suggest
using ExpressPCB's software. With a completed board layout in hand, you
can either go
with ExpressPCB's fab system or use Copper Connection's software for
producing Gerber
data from ExpressPCB's proprietary format.

With Gerber data in hand, you're free to use any board fabricator that
meets your price,
delivery schedule, and quantity needs. I've had good results using
OSHPark, a design
aggregator.

OTOH, if you need one-off single-sided boards that don't have small
traces or dense
layouts, CNC machining bypasses the trace-transfer and
chemical-immersion steps
that consume time and possibly require several retries to produce usable
boards.

I'm interested in reading others' comments. A benchtop CNC machine would
be nice to have...
as soon as I unearth the top of one of my workbenches<g>.

73--

Brad AA1IP