Hul Tytus wrote:

rec.crafts.metalworking
high-speed spindles

Harbor Freight's 1/4 inch electric die grinder was tried, first for
drilling some small diameter holes in aluminum blocks and then milling
solder paste stencils in 3 & 5 mil brass sheet.

I've been making solder stencils using the exact same process and
equipment I used to make PC boards. I use 3 mil brass shim stock
(I started with 5 mil, but the 3 mil works better).
I wet-sand the brass to remove an oil or plastic film that prevents
tarnishing. I use a hot roll laminator used for laminating dry
film photoresist to PC boards to put the resist on both sides of the
shim stock, using a paper shim to get the right roll pressure (as
the machine is adjusted for laminating .062" PC board stock).
I run the brass through the laminator twice to get both sides
coated with resist.

I built a laser photoplotter some years ago, and make two
master artworks, one a mirror image of the other. I glue
the two artworks together, aligning them on a light table.
I slip the resist-coated shim stock between the artworks
and put in a vacuum frame, and expose both sides to UV.
I develop in dry film developer and etch in a spray etcher
with ferric chloride for about 2 minutes.

The big problem with this is figuring out the right aperture
size for each pad size. I am getting this process dialed
in, and the boards are coming out better and better. I
do some parts with lead pitches down to 0.4 mm, which is
real tricky. SO and even SSOP chips are working perfectly
now, but anything smaller than 0.65 mm and I have some
bridging.

Jon

Jon - sounds like you have a good process for the stencils but you had the
advantage, initially at least, of using it also for pc boards. In terms of
time & money, assembling the equipment needed just for stencils is costly.
On another subject, have you found an easily interfaced merchant
account for credit cards for your web site? I'm planning on selling some
electronic gear over the internet and I'm looking for suggestions on
handling the cards.

Hul

Jon Elson wrote:
Hul Tytus wrote:

rec.crafts.metalworking
high-speed spindles

Harbor Freight's 1/4 inch electric die grinder was tried, first for
drilling some small diameter holes in aluminum blocks and then milling
solder paste stencils in 3 & 5 mil brass sheet.

I've been making solder stencils using the exact same process and
equipment I used to make PC boards. I use 3 mil brass shim stock
(I started with 5 mil, but the 3 mil works better).
I wet-sand the brass to remove an oil or plastic film that prevents
tarnishing. I use a hot roll laminator used for laminating dry
film photoresist to PC boards to put the resist on both sides of the
shim stock, using a paper shim to get the right roll pressure (as
the machine is adjusted for laminating .062" PC board stock).
I run the brass through the laminator twice to get both sides
coated with resist.

I built a laser photoplotter some years ago, and make two
master artworks, one a mirror image of the other. I glue
the two artworks together, aligning them on a light table.
I slip the resist-coated shim stock between the artworks
and put in a vacuum frame, and expose both sides to UV.
I develop in dry film developer and etch in a spray etcher
with ferric chloride for about 2 minutes.

The big problem with this is figuring out the right aperture
size for each pad size. I am getting this process dialed
in, and the boards are coming out better and better. I
do some parts with lead pitches down to 0.4 mm, which is
real tricky. SO and even SSOP chips are working perfectly
now, but anything smaller than 0.65 mm and I have some
bridging.

Jon

wrote:

Jon - sounds like you have a good process for the stencils but you had the
advantage, initially at least, of using it also for pc boards. In terms of
time & money, assembling the equipment needed just for stencils is costly.
Yes, the accuracy of laser printers makes it unlikely this would work
well from a laser printed transparency film as the master artwork,
especially as you need mirror image films that have to align pretty well.

On another subject, have you found an easily interfaced merchant
account for credit cards for your web site? I'm planning on selling some
electronic gear over the internet and I'm looking for suggestions on
handling the cards.

I am using Merchant Warehouse, with Authorize.net as the payment
gateway. Between the two, it costs about $45 a month to have these
accounts. Merchant Warehouse has a minimum $35 fee.

Using OScMax, they only have an interface to Authorize.net AIM, but not
their SIM. AIM has your web site receiving the credit card #, which
then means you need to be PCI compliant. I'd much rather use the SIM
interface, which shifts the customer over to Authorize.net's web page
to do the credit card transaction, but OScMax doesn't have an interface
for that. The PCI compliance nightmare keeps me up at night.

Anyway, unless you are at least as serious about an on-line business
as I am, you really DON'T want to get involved in this, it will take
a LOT of time to make it work and keep it secure.

Jon

Jon - thanks for the suggestions about credit cards, especially
authorize.net's AIM & SIM interfaces.

Hul

Jon Elson wrote:
wrote:

Jon - sounds like you have a good process for the stencils but you had the
advantage, initially at least, of using it also for pc boards. In terms of
time & money, assembling the equipment needed just for stencils is costly.
Yes, the accuracy of laser printers makes it unlikely this would work
well from a laser printed transparency film as the master artwork,
especially as you need mirror image films that have to align pretty well.

On another subject, have you found an easily interfaced merchant
account for credit cards for your web site? I'm planning on selling some
electronic gear over the internet and I'm looking for suggestions on
handling the cards.

I am using Merchant Warehouse, with Authorize.net as the payment
gateway. Between the two, it costs about $45 a month to have these
accounts. Merchant Warehouse has a minimum $35 fee.

Using OScMax, they only have an interface to Authorize.net AIM, but not
their SIM. AIM has your web site receiving the credit card #, which
then means you need to be PCI compliant. I'd much rather use the SIM
interface, which shifts the customer over to Authorize.net's web page
to do the credit card transaction, but OScMax doesn't have an interface
for that. The PCI compliance nightmare keeps me up at night.

Anyway, unless you are at least as serious about an on-line business
as I am, you really DON'T want to get involved in this, it will take
a LOT of time to make it work and keep it secure.

Jon

wrote:

Jon - thanks for the suggestions about credit cards, especially
authorize.net's AIM & SIM interfaces.

If you find a good web store that works with Authorize.net SIM, or
another good payment gateway that you can use without having to
be PCI compliant, I'd sure be interested. I'm not a PHP coder although
I can generally follow what is going on in the osCmax scripts and
make very small changes, I'm nowhere up to speed to try rolling my own
interface to Authorize.net's SIM.

Jon

Jon - if you are familiar with the C programming language, you might
look... it's been a few years and I'm not up on the proper buzz words;
stated more generally: there is an http:// interface attachment for Unix
systems, something or other C this that..., which enables coding internet
pages with c. You would probably find the name of the attachment
and the name of the company that makes it familiar.
Whether this would be an advantage with Authorize.net's Sim interface is
merely hope on my part. Take a look at rs-big-print.com to see what has
been done so far.

Hul

Jon Elson wrote:
wrote:

Jon - thanks for the suggestions about credit cards, especially
authorize.net's AIM & SIM interfaces.

If you find a good web store that works with Authorize.net SIM, or
another good payment gateway that you can use without having to
be PCI compliant, I'd sure be interested. I'm not a PHP coder although
I can generally follow what is going on in the osCmax scripts and
make very small changes, I'm nowhere up to speed to try rolling my own
interface to Authorize.net's SIM.

Jon