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Re: Removing photoresist

 

Could it be a photoresist that develops with an alkali process? Sodium Hydroxide perhaps? NaOH


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On Wed, Oct 13, 2021 at 7:31 PM Morris Odell <vilgotch1@...> wrote:
Alas not, I've tried both acetone and IPA and they don't touch it. I'll try MEK but I'm reluctant to try paint stripper because of methylene chloride toxicity.

Morris

Re: Removing photoresist

 

Alas not, I've tried both acetone and IPA and they don't touch it. I'll try MEK but I'm reluctant to try paint stripper because of methylene chloride toxicity.

Morris
Re: Removing photoresist

 

Acetone will do a quick job of this.

Tom
Re: Removing photoresist

 

I used to use 99% IPA to remove resist after exposing and etching PCBs.

Leon

On 13 Oct 2021 10:11, Morris Odell <vilgotch1@...> wrote:
Hi all,

I picked up a large sheet of surplus single sided copper clad board that is coated with a reddish colored photoresist. I don't know anything about it or whether it's positive or negative. I would like to remove the photoresist and just leave the copper layer so I can use it for toner transfer. The resist is not affected by acetone, turpentine or naphtha.

Any advice on where to go from here would be much appreciated.

Thanks,

Morris

Removing photoresist

 

Hi all,

I picked up a large sheet of surplus single sided copper clad board that is coated with a reddish colored photoresist. I don't know anything about it or whether it's positive or negative. I would like to remove the photoresist and just leave the copper layer so I can use it for toner transfer. The resist is not affected by acetone, turpentine or naphtha.

Any advice on where to go from here would be much appreciated.

Thanks,

Morris
Re: DIY SMT solder stencil making

 

The idea of using brass...
Re: DIY SMT solder stencil making

 

I like it !!!!!!
Re: Use of hashtags

 

I never got into the whole hashtag thinking?either.

On Mon, Oct 11, 2021 at 12:59 PM Steven Greenfield AE7HD via <alienrelics=[email protected]> wrote:

It doesn't matter, I cannot get consistent use of the hashtags. I did some experiments on the Electronics101 list, and they all failed.?

--
Steven Greenfield AE7HD

Re: Use of hashtags

 

It doesn't matter, I cannot get consistent use of the hashtags. I did some experiments on the Electronics101 list, and they all failed.?

--
Steven Greenfield AE7HD
Re: DIY SMT solder stencil making

 

You've got ferric Chloride or something similar, so use your toner transfer on thin copper or brass sheet
the very first stencils I made were on 0.15mm brass sheet, but that is thicker than what is actually required.
so I'd go for 0.075 or 0.1 at a push..?? that stencil made 18 years ago is still in use today? !

Chris
Re: DIY SMT solder stencil making

 

0.075 mm brass?????? use your toner transfer and etch using your normal pcb etching chemicals
Re: DIY SMT solder stencil making

 


Looked really interesting.
Re: DIY SMT solder stencil making

 

Re: DIY SMT solder stencil making

 

开云体育

Normally the “Paste Layer” is part of the Gerber files so only turn on that layer.

To avoid confusion, note that the Paste layer is different from the solder mask layer.

Bertho

?

From: [email protected] <[email protected]> On Behalf Of Steven Greenfield AE7HD via groups.io
Sent: Sunday, October 10, 2021 1:34 PM
To: [email protected]
Subject: Re: [homebrewpcbs] DIY SMT solder stencil making

?

Don't most PCB CAD programs include the ability to generate a solder mask? If not, I'd think you could generate an image of the PCB with nothing but the pads.

--
Steven Greenfield AE7HD

Re: DIY SMT solder stencil making

Jim Higgins
 

Received from Jim Pruitt at 10/10/2021 08:09 UTC:

Anyway reversing the image and (toner) transferring the layout to the piece(s) of stainless steel stock and then etching using the hydrochloric acid and hydrogen peroxide formula might work.

I wouldn't count on hydrochloric acid and hydrogen peroxide having much effect on most stainless steel. For sure I'd test it on a piece before going to the trouble of applying a toner transfer.

JimH
Re: DIY SMT solder stencil making

 

Don't most PCB CAD programs include the ability to generate a solder mask? If not, I'd think you could generate an image of the PCB with nothing but the pads.

--
Steven Greenfield AE7HD
Re: Use of hashtags

 

I don't understand this Hashtag thing. What is happening?
--
-- The only difference between men and boys, is the price of their toys.
Re: DIY SMT solder stencil making

 

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Steven,

have you found a page with the various smt IC footprints shown?? I was in need of several temples but realized that if I can find some thin sheetmetal stock (like K&S and others sell) then grabbing the particular IC or part footprint could make a stainless steel stencil easily. The only trick and it is not much of a trick any more is that the footprint (assuming that toner transfer method is going to be used and not photo sensitive methods) would have to be converted to a negative since the pads are what get etched away to make holes in the stencil.? Anyway reversing the image and (toner) transferring the layout to the piece(s) of stainless steel stock and then etching using the hydrochloric acid and hydrogen peroxide formula might work.? I ended up just buying some of the Proto-Advantage stencils but at $12 a pop for a tiny piece of thin stainless steel it adds up in a hurry.

Thank you.

Jim Pruitt
WA7DUY
?

On 10/9/2021 8:00 AM, Steven Greenfield AE7HD via groups.io wrote:

If you can get your hands on an old pen plotter, you might be able to put an inexpensive Roland vinyl cutter head into it. Inkscape has offset drag compensation for at least some plotters.

Then you could try cutting solder paste stencils from mylar sheets.

This might also work with one of those relatively inexpensive laser diodes that are generally sold as add-ons to CNC machines. They are quite a bit heavier than a pen, so a pen plotter would likely need the acceleration and speed settings adjusted. Which is part of using a laser diode, anyway.

--
Steven Greenfield AE7HD

Re: Spare tips for ORYX 50 soldering iron ?

 

Here's one source that a quick Google search found:
?<??>

I suspect one of the auction sites probably has some listings.

Roy
Spare tips for ORYX 50 soldering iron ?

 

Can anyone advise me where I can obtain some ???

Regards
Dave
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