Toner Transfer Papers

[KeepItSimpleStupid]

Here's a tutorial on screen-print technology: https://gomedia.com/zine/insights/low-budget-screen-printing-a-newbies-guide/

here, https://en.wikipedia.org/wiki/X-ray_lithography in the "See also" category is a list of different lithography technologies that can obtain different resolutions.

The real technique for PCB fabrication is the Photoplotter. See a home made one here: https://pico-systems.com/photoplot.html

 

[mvs sarma]

Sounds awesome! But it seems that the project needs little more strange materials/chemicals. It is pretty hard way for a people living in less accessible place like me.

There are no strange chemicals. After transferring the artwork, you just need topeel out the yellow sheet while it is semi hot (say 1 minute after toner transfer. )
you can etch a pcb as you had been doing.

 

[Mosaic]

Seems I have spawned a downstream biz: (no affiliation)
**broken link removed**

 

[camerart]

Hi,
As I don't possess an iron, but have a toaster, I thought I'd try that.

I'm only making small PCBs at the moment 30X40. I cut 2x 2mm sheets larger than the PCB drilled 4x holes in each corner. Placed the PCB on the bottom ali sheet, then yellow transfer paper with circuit, then a silicon sheet, then the top ali sheet. bolt it all together, but not too tight so it bends. Put it in the toaster for 1.5 minutes. leave till warm, remove and peel paper.

For this simplicity test: Ferric chloride in a chemical glass, heat till near hot and agitate the PCB for 20ish minutes.

Good result!
C.

 

[Mosaic]

pics?

 

[throbscottle]

Hi,
As I don't possess an iron, but have a toaster, I thought I'd try that.

I'm only making small PCBs at the moment 30X40. I cut 2x 2mm sheets larger than the PCB drilled 4x holes in each corner. Placed the PCB on the bottom ali sheet, then yellow transfer paper with circuit, then a silicon sheet, then the top ali sheet. bolt it all together, but not too tight so it bends. Put it in the toaster for 1.5 minutes. leave till warm, remove and peel paper.

For this simplicity test: Ferric chloride in a chemical glass, heat till near hot and agitate the PCB for 20ish minutes.

Good result!
C.

I am in awe of your ingenuity!

 

[camerart]

pics?

Here's a PIC.

Sandwich TOP PLATE-SILICON-TONER PAPER-PCB-BOTTOM PLATE. Bolt lightly so as not to buckle Ali plates.

My old 60s toaster has good elements! 1 Minute over 100DEG C 2Minutes 200DEG C.

200 DegC will aneal (Soften) the aluminium, so in this case 1Minute 20 Secs. leave till warm and pull/peal apart.

NOTE: this was a quick test! The aluminium sheet should be thicker for larger PCBs, or another metal used, e,g, brass? (or it will buckle) I will add re-inforcing bracing 'Silver soldered' on the rear of each plate. (Not soldering iron solder, much hotter), then try again.

C.

 

[Mosaic]

Good effort, but: Once you start doing 6" PCBs etc...that squeeze plate method won't work very well, there'll be high & low pressure spots which smear the toner or don't transfer it.
After dropping to about 50% success rates with the iron for larger boards I got the Apache AL13P and I have a 95% rate with big boards now. A silver sharpie makes it 100%.

10 mil traces and 0603 parts are common items for me.

 

[camerart]

Good effort, but: Once you start doing 6" PCBs etc...that squeeze plate method won't work very well, there'll be high & low pressure spots which smear the toner or don't transfer it.
After dropping to about 50% success rates with the iron for larger boards I got the Apache AL13P and I have a 95% rate with big boards now. A silver sharpie makes it 100%.

10 mil traces and 0603 parts are common items for me.

Hi, I was editing my post, have another look. C

 

[Mosaic]

If you want to use rigid plates, make them with 1/4" Alum angles. Polish the Al angles flat on a sheet of glass with 220 grit sand paper stuck to the glass.

 

[camerart]

If you want to use rigid plates, make them with 1/4" Alum angles. Polish the Al angles flat on a sheet of glass with 220 grit sand paper stuck to the glass.

Hi M,
I get your point about the problem with large plates, I suggested using thinner plates with re-inforced webbing, to speed up the heating/cooling time, instead of thicker ones.

I have yet to find out from my posted test, whether the heat is coming from the side with silicon or not. If it can come from the silicon, then double sided PCBs could be produced.
C.

 

[camerart]

If you want to use rigid plates, make them with 1/4" Alum angles. Polish the Al angles flat on a sheet of glass with 220 grit sand paper stuck to the glass.

Hi again M,
You have reminded me about Engineers blue (Microscope) and hours of scraping
C.

 

[camerart]

Hi,
I've been thinking about making stiffer plates, but more accessible to the hobbyist.

My plates are 2mm and are just starting to bend. If plates of perhaps 5 or 6mm and drill honeycomb on the back, stopping just before the drill breaks through. (Or preferably an end-mill: https://www.ebay.co.uk/itm/3-Flute-...utter-Drill-HSS-2-to-12m-111926-/291809266989) This would give the stiffness while also heating and cooling more quickly. As long as the whole sandwich fits in the toaster.
C.

 

[Mosaic]

I think using the toaster as a preheater for the PCB and passing the toner transfer PCB thru a hot paper laminator a couple times would be more reliable.

 

[camerart]

Hi,
I just tried double sided, with the same sandwich, to prove that the heat can pass through the silicon. It can!
However there were signs of lack of pressure at the same edge both sides, and scaling up would exaggerate this affect, so I think you maybe correct, that it may not be 100%.
I'm sure I could develop this method, perhaps with dissimilar metals, which would try to bow in the centre, so kind of sending a pressure wave from external to the centre, but life's too short.

So, where's the sandwich maker

I'll buy a laminator!
From what you say they need more than one pass. Is it time, pressure or heat, that's lacking? I presume they have a fixed speed, so perhaps they should have slower travel?
Note: Pre-heating with a toaster before laminating, would give the leading edge more heat than the cooling rear edge!
C.

 

[camerart]

Hi,
Just looking at laminators (and modifications) Do you think this would work? **broken link removed**
C.

 

[Mosaic]

Look for my Ebay item 132136993019.
It is a mod for laminators to do the multipass automatically. Follow the DIY instructions link for the open sourced build if you prefer.

Someone else also took the mod. as I open sourced it and is producing laminators with built-in capabilities. Ebay Item: 232310781501, no affiliation.

 

[camerart]

Look for my Ebay item 132136993019.
It is a mod for laminators to do the multipass automatically. Follow the DIY instructions link for the open sourced build if you prefer.

Someone else also took the mod. as I open sourced it and is producing laminators with built-in capabilities. Ebay Item: 232310781501, no affiliation.

Hi M,
Interesting well done!
First I would like to know why it needs two passes? I asked this before: Is it lack of heat, time or pressure?
C.

 

[Mosaic]

Copper spreads heat fast, especially double sided 2Oz, thus the localized roller contact is insufficient at full laminator speed to achieve dependable toner transfer temperatures. Thus a multipass approach is optimum giving focused, consistent roller pressure and getting the heat to do the transfer.

 

[camerart]

Copper spreads heat fast, especially double sided 2Oz, thus the localized roller contact is insufficient at full laminator speed to achieve dependable toner transfer temperatures. Thus a multipass approach is optimum giving focused, consistent roller pressure and getting the heat to do the transfer.

Hi M,
Ok, thanks.
I've never seen inside a laminator, or know exactly how they work, but I presume either the rollers get hot, or there is a heater near the pinch point.
My logic 'says' either give more heat (Which may be too much for the rollers etc) or slow the feed down. This would give longer to get the heat into the PCB sandwich. I would first try to slow the feed down, with a speed controller.
My thoughts on the multi path approach, is: To make the point, this is exaggerated! Imagine the board was a meter long, the board would have cooled down a bit , before the second pass.
I accept that you're having good success with the multipass, so, I'll try that second
C.