开云体育

HI,

Just diving back into Kicad 6 after being away from it for a while.? Needed to do a small PCB which I've milled successfully and have tested.

Since this is a one off I'm not planning on sending it out to a board house and I just for fun wanted to try doing a silk screen using the toner transfer method.

In the PCB Editor the view is from the bottom of the board, but it looks like the F.Silkscreen is displaying as if it was on the bottom of the PCB.

So I tried printing the F.Silkscreen Mirrored.? But while that gives me horizontal text that would transfer OK the rest of the board is flipped as well so that is not going to work.

For example I have a connector that is in the upper left corner of the PCB (looking at the top of the PCB) and another connector that is about in the middle on the right hand side of the PCB.

The mirrored print of the F.Silkscreen layer has then one connector in the upper left corner and the other one in the middle on the right side.

But when you turn the printed layer over to transfer the toner to the PCB you now have the first connector in the upper RIGHT corner and the 2nd one in the middle on the LEFT side, which of course is incorrect.

If I print the F.Silkscreen without mirroring then it will transfer properly as far as component locations and vertical text, but horizontal text would be reversed.

So what am I missing?? Is there a way to do what I'm trying to accomplish?

I guess for now I can change all the horizontal text to vertical orientation and print without mirroring.

Thanks,
Burt

I've only just got kicad up and running due to a system rebuild (linux)
Also I've not yet used K6 in anger, However all you need is a mirrored
plot

I've just outputted the f-silkscreen of the demo PIC programmer project
and it looks correct. The print is all backwards, but printed on the
top of the paper, so when flipped over everything is as needed. Ready to
be transferred top the top of the board.

Now there is ONE difference which might be a clue. Because I'm a bit of a
cheapskate I tend to cut the film I use in half as most things I make
are less than A5 size and that means I need to move the print to a more
convenient location, so I've always PLOTTED to pdf rather than PRINTING.

It also helps that the linux printing system is basically a pdf format
anyway and is easy to manipulate.

I've attached the output pdf that it produced.

Andy


On Thu, 03 Mar 2022 13:00:42 -0800
burt@... wrote:

HI,

Just diving back into Kicad 6 after being away from it for a while.? Needed to do a small PCB which I've milled successfully and have tested.

Since this is a one off I'm not planning on sending it out to a board house and I just for fun wanted to try doing a silk screen using the toner transfer method.

In the PCB Editor the view is from the bottom of the board, but it looks like the F.Silkscreen is displaying as if it was on the bottom of the PCB.

So I tried printing the F.Silkscreen Mirrored.? But while that gives me horizontal text that would transfer OK the rest of the board is flipped as well so that is not going to work.

For example I have a connector that is in the upper left corner of the PCB (looking at the top of the PCB) and another connector that is about in the middle on the right hand side of the PCB.

The mirrored print of the F.Silkscreen layer has then one connector in the upper left corner and the other one in the middle on the right side.

But when you turn the printed layer over to transfer the toner to the PCB you now have the first connector in the upper RIGHT corner and the 2nd one in the middle on the LEFT side, which of course is incorrect.

If I print the F.Silkscreen without mirroring then it will transfer properly as far as component locations and vertical text, but horizontal text would be reversed.

So what am I missing?? Is there a way to do what I'm trying to accomplish?

I guess for now I can change all the horizontal text to vertical orientation and print without mirroring.

Thanks,
Burt

Thanks Andy,

I'll try plotting to PDF like you were doing.? When I just try printing the F.Silkscreen Mirrored the text is mirrored, but the footprints also appear to be flipped, and looking at how the silk screen would be transferred it definitely would not be correct in my case.

I did find a work around but it's a bit of a pain.? If I select all of the text on the Silkscreen layer, including all of the associated footprint references and click on mirror the text then when I print without selecting the mirror of the layer I get a proper transfer and after applying it to the PCB everything is correct, all the lettering is properly oriented and all of the components are in their proper locatinos.

So tomorrow I'll give it a shot with plotting to a PDF and see if that makes a difference.? Hoping it does for future boards.

Thanks again,
Burt

Hope it works Burt,

I've been using Kicad for a long time, version 2 or 3 I think.
I do recall that printing did have a few problems, early on, but once I
started to use the photo resist type boards I needed to mirror the output
so that the toner was in direct contact with the photoresist before UV
exposure. Which is exactly what you need for the silk screen.

I've been using plot to pdf for that method ever since.

I'm now trying out coating the boards myself with photo resist film,
which in addition to mirror needs a negative print as well (the film is a
positive type)

Andy


On Thu, 03 Mar 2022 17:10:14 -0800
burt@... wrote:

Thanks Andy,

I'll try plotting to PDF like you were doing.? When I just try printing the F.Silkscreen Mirrored the text is mirrored, but the footprints also appear to be flipped, and looking at how the silk screen would be transferred it definitely would not be correct in my case.

I did find a work around but it's a bit of a pain.? If I select all of the text on the Silkscreen layer, including all of the associated footprint references and click on mirror the text then when I print without selecting the mirror of the layer I get a proper transfer and after applying it to the PCB everything is correct, all the lettering is properly oriented and all of the components are in their proper locatinos.

So tomorrow I'll give it a shot with plotting to a PDF and see if that makes a difference.? Hoping it does for future boards.

Thanks again,
Burt

Thanks Andy,

What worked for me was to mirror all the text on the Front Silk Screen layer, print non-mirrored to the transfer paper.? That gives the transferred silk screen with the components in the proper locations and the text transferred correctly.


Have you tried a DIY solder mask?? ?If so and you use the dry film method where did you get your solder mask film?

I'm looking for a supplier of the dry solder mask sensitized film but so far have only found one in Slovkia listed on eBay.? I was hoping to find another supplier here in the states, but no luck so far.? I have the UV solder mask paste but that is a bit of a pain to apply consistently.

I have been considering the sensitized photo resist film for some testing in the future.? ?My plan is to drill and cut out the PCB on my CNC mill, then apply the UV film, expose and process the resist and etch the board.

Burt

Hi Burt,

Glad it worked out in the end, even if it's a bit of a fiddly process :-)

I've never tried diy solder mask, and the main supplier of soldering
products over here in the uK that I used (Mega) went out of business a
couple of years ago.

I have found one company in the UK that does the stuff:



I have never used it.

They may have a US distributor.

Your method with the mill etc may work OK (I don't have a cnc mill) but
my trials with the dry film show that you need a very good surface for it
to apply well. I clean and polish the board, then lightly wet it, and
apply the film. I used a wad of paper towel to squeegee out the water and
smooth the film, than a few passes through the laminator ensures that
it adheres nicely. This process does not like burrs and any raised edges
which any cutting and drilling may leave, So I do all that after the film
and etching.

Andy

On Sun, 13 Mar 2022 05:26:40 -0700
burt@... wrote:

Thanks Andy,

What worked for me was to mirror all the text on the Front Silk Screen layer, print non-mirrored to the transfer paper.? That gives the transferred silk screen with the components in the proper locations and the text transferred correctly.

Have you tried a DIY solder mask?? ?If so and you use the dry film method where did you get your solder mask film?

I'm looking for a supplier of the dry solder mask sensitized film but so far have only found one in Slovkia listed on eBay.? I was hoping to find another supplier here in the states, but no luck so far.? I have the UV solder mask paste but that is a bit of a pain to apply consistently.

I have been considering the sensitized photo resist film for some testing in the future.? ?My plan is to drill and cut out the PCB on my CNC mill, then apply the UV film, expose and process the resist and etch the board.

Burt

Thanks Andy,? I did locate a couple of other sellers here in the US, but they don't sell small quantities so if I use them I'd have to buy a lot of the dry film.? Since initially I just want to test it out I'll check out Fortex.

I already clean all the burrs and raised edges from the milling process.? Kind of need to do that for the UV solder mask paste process as well.

If I get some dry film solder mask I'll try your tips on what you found when working with it.

Burt