PCB Photo sensitizing options

[bob4bvm]

With MG Chem dropping out, what are current option for blank boards with photoresist coating ?
I saw once somewhere where a guy was using silkscreen resist liquid to coat bare Cu boards. Anyone tried that ? I believe it takes negative artwork but that's no problem really
Thx
Bob

 

[augustinetez]

I used to use that type of ink - Taiyo UV printing ink ( I think it's changed name now).

Yes, it's negative artwork and I never had any problems using it but it is not cheap.

You also need to make sure you use it under as near a UV light free environment as possible ( I bought special UV free flouro's for my workshop).

Last time I bought some, a 1L pot was nearly $100 AUD (and that was 10+ years ago).

Only reason I stopped using it is because it works out cheaper to get pcb's made in one of many various places if you have the time to wait for delivery.

 

[Pommie]

Only reason I stopped using it is because it works out cheaper to get pcb's made in one of many various places if you have the time to wait for delivery.

Same here. Quality double sided plated through boards are so cheap to get profesionally made that it's not worth making your own. I use JLCPCB, 5 boards 100mmx100mm double sided for $2!!!!!!.

Mike.

 

[Nigel Goodwin]

Same here. Quality double sided plated through boards are so cheap to get profesionally made that it's not worth making your own. I use JLCPCB, 5 boards 100mmx100mm double sided for $2!!!!!!.

Mike.

Yes, I wouldn't consider trying to make my own boards - only 'problem' with JLCPCB (and all others) is the high courier cost from the other side of the world. The boards might be $2 for 5, but the postage is likely to be more than $20.

The $2 offer makes it look particularly bad though - normal priced orders (which aren't that much dearer anyway) don't look 'too bad' for higher quantities, even though postage soon reaches three figures. The order I received yesterday, for 600 boards, worked out at under 30 pence per board, all in - but £120+ postage makes you cringe a bit.

 

[For The Popcorn]

I compared the cost of getting boards made at one of major US suppliers compared to one of the Chinese fabs. Even considering shipping costs, I think even at 5,000 boards the Chinese option was far cheaper.

 

[Nigel Goodwin]

I compared the cost of getting boards made at one of major US suppliers compared to one of the Chinese fabs. Even considering shipping costs, I think even at 5,000 boards the Chinese option was far cheaper.

I'm pretty sure it'll be cheaper at any quantity

When I first started ordering PCB's I approached the UK based company that my boss had used before to get a quote, and I also mentioned (to my boss) that I'd seen this advert for cheap boards from JLCPCB. So after I'd emailed the gerber files for a quote, I went on JLCPCB and placed an order from them.

It took three days for the UK company to provide the quote, by that time JLCPCB had already manufactured the boards and they were on their way. The boards arrived five days after ordering, so needless to say we never bothered with the UK company.

The UK quote was considerably higher, and MUCH slower - as I recall they would take two weeks after order before they would even give us a suggested delivery date.

Never used anyone else since, and I've been perfectly happy with all the boards we've had.

 

[bob4bvm]

Yes i am aware of the cheap china board services.
That was not my question.
As a retired guy who does some builds for other hobbies, Almost all are one-off builds, i have no need for 600 copies of the same board.
i still like being able to design a board and have it in my hand the same day to try out. Printing a pattern transparency, exposing the board, and etching it is all done in under 30 minutes. Waiting even a week or two does not interest me. If i need to do mods, it's another 30 min to a new board.''As for cost, i have on hand a ton of good bare 1-oz. fr4 but i am fresh out of MG photo-sens material with no source for more.
So can anyone answer my original question ?
Thx
Bob

 

[Pommie]

So can anyone answer my original question ?

I'm afraid I can't. I suspect, due to the readily available cheap boards these chemicals are becoming increasingly rare and expensive. Good luck finding them.

And, as stated above you can have 5 boards if you so desire - no need to order 600.

Mike.

 

[Nigel Goodwin]

Yes i am aware of the cheap china board services.
That was not my question.
As a retired guy who does some builds for other hobbies, Almost all are one-off builds, i have no need for 600 copies of the same board.
i still like being able to design a board and have it in my hand the same day to try out. Printing a pattern transparency, exposing the board, and etching it is all done in under 30 minutes. Waiting even a week or two does not interest me. If i need to do mods, it's another 30 min to a new board.''As for cost, i have on hand a ton of good bare 1-oz. fr4 but i am fresh out of MG photo-sens material with no source for more.
So can anyone answer my original question ?
Thx
Bob

You can probably find them next to the buggy whip aisle?

Those days are long gone, even standard components are difficult to source these days (even like 1K resistors), so rarely used obscure chemicals are going to be pretty hard to find - I would imagine lack of demand meant the manufacturers stopped producing them?.

 

[rjenkinsgb]

This make of photoresist aerosol seems to be fairly widely available?

82009, Novolack, O-Naphto-Chinon-Diazide Etching Chemical for Etching in Liquid | RS Components

uk.rs-online.com

Or "Fortex" brand for pre-coated board:

Photoresist Presensitised PCB Board Microtrak ‘FR4’ Positive – Double-Sided – Fortex Engineering Ltd

www.fortex.co.uk

 

[bob4bvm]

Thx for the process feedback guys, but you are missing my point. Cheap-cheap does not matter to me since this is hobby stuff for me these days.
What matters is the instant availability that DIY boards provide. I can have my project up and running before your buggy ever leaves the barn, Then if it needs mod's it's another 30 minute process to a new board. So believe it or not there is still a place for DIY boards.
Cheers
Bob

 

[bob4bvm]

Excellent, Thank You rjenkinsgb !

The coating looks like a great option for me, Exactly what i was hoping to find. Will give it a try
Cheers,
Bob