Hey, I've noticed fr4 type pcbs overtime went from murky light green to now yellow. Anyone know what to specify when ordering pcbs to get the watery green type? Recreating clones of old pcbs, would like it to look similar. Typically one sided boards with no mask. Thanks!
Anyone know how to order pcbs like this?
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zamproject
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To me it just look like raw glass fibre pcb without (coloured) varnish ?
It's easy to do with restricted mask area (at leas with KiKad that I use).
Now the advantage of proper PCB finish with solder mask is the copper traces being protected from oxidation...
It's easy to do with restricted mask area (at leas with KiKad that I use).
Now the advantage of proper PCB finish with solder mask is the copper traces being protected from oxidation...
Brian Roth
Well-known member
I don't have a good answer for you. I can only make some comments from when I was "in the trenches" circa 1970's into the 80's.
Back them, FR-4 came in any color you wanted.....as long as it was a shade of green (or so it seemed)! See pic below from a desk module prototype I built.
As you can see, the PCB house I was using (a local company) stocked two different brands of FR-4. AFAIK, that's all they offered. So, the shade of green depended on their stock on any given day. Other PCB companies were the same way.
Solder mask was an expensive option for low-medium sized runs, as were double-sided boards. To protect the exposed copper traces, pro PCB companies either solder plated the traces or used an electroless tin plating option.
In 2025, I guess you'll have to inquire at each potential supplier (maybe ask for a sample) and see if you find something close. Wish I had more suggestions.....
Bri
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The soldermask-free areas on my PCBs from PCBWay and JLCPCB look greenish. So I'd just order from there.
These soldermask-free areas are within guardring loops. But I keep the rest of the board covered with soldermask for the reasons already mentioned by other members and to prevent solder bridging. Enjoy the progress of technology!
Jan
These soldermask-free areas are within guardring loops. But I keep the rest of the board covered with soldermask for the reasons already mentioned by other members and to prevent solder bridging. Enjoy the progress of technology!
Jan
Matador
Well-known member
Just ask the board house to skip the soldermask layers, and you'll get the blank un-colored FR4 material with exposed bare copper.
You also need to ask the board house if they can support HASL or ENIG (or even Sn immersion) if there is no soldermask - I seem to recall, that HASL was possible without soldermask, but not ENIG (but ask them to confirm).
You also need to ask the board house if they can support HASL or ENIG (or even Sn immersion) if there is no soldermask - I seem to recall, that HASL was possible without soldermask, but not ENIG (but ask them to confirm).
Matador
Well-known member
I forgot to say: skipping the soldermask is a Horrible Idea (TM). Not only does soldermask prevent oxidation of the traces:
1) It greatly reduces moisture penetration/contamination
2) Reduces the chances of shorting traces with tools/test clips/probes/etc.
3) Stops solder from wicking up the trace, thereby draining it from the connection(s) you are trying to make
4) Silkscreens have more contrast, and sharper printing of edges (e.g. look better)
5) Makes it harder to bridge between adjacent pads
6) Easier to clean flux residue with stronger solvents without damaging anything on the board
1) It greatly reduces moisture penetration/contamination
2) Reduces the chances of shorting traces with tools/test clips/probes/etc.
3) Stops solder from wicking up the trace, thereby draining it from the connection(s) you are trying to make
4) Silkscreens have more contrast, and sharper printing of edges (e.g. look better)
5) Makes it harder to bridge between adjacent pads
6) Easier to clean flux residue with stronger solvents without damaging anything on the board
Brian Roth
Well-known member
The OP was trying to duplicate the "look" of vintage PCBs. It was very common for those to be single sided with no solder mask (and often no silk screening of legends). Not ideal in our times, but very common on plenty of boards found in pro gear.
Bri
Bri
Good to confirm what I am doing is the move, emailing pcb houses! Or I can order some without mask and see how they come out.
I understand the conventions of modern design, just want to remake some vintage cards. I’m still using vintage consoles with one sided no mask boards, no big issues so not super concerned about oxidation for the project. I also just don’t really like the color yellow lol. Cheers.
I understand the conventions of modern design, just want to remake some vintage cards. I’m still using vintage consoles with one sided no mask boards, no big issues so not super concerned about oxidation for the project. I also just don’t really like the color yellow lol. Cheers.
MidnightArrakis
Well-known member
>> Several years ago I was contacted by some GroupDIY member who had purchased an original 1974 API mixing-console and his personal project was going through and doing a complete restoration of its electronics. And.....what this meant for him was that he had wanted -- ALL NEW "OLD" PCB's -- designed for his console!!! So.....he contacted me to design for him all "NEW/OLD" PCB's to be -- JUST LIKE THE ORIGINAL OLD PCB's -- that were in his console.
I had him physically mail me one-each of each different PCB so I could replicate each board as they had been originally designed. When I received his small package and looked at each one of these original PCB's, it became immediately apparent to me that all of these old boards could very easily be improved upon with virtually no added effort on my part. What did I see??? -- Improvements in their components placement, improvements in their layout-routing, the addition of using a soldermask and improvements to the general silk-screening. Sometimes when I look at how these old PCB's had been originally designed, I'm amazed that they even worked at all!!!
So.....I sent the guy an e-mail message to not only provide him with a quote of how much it would cost for me to completely redo all of his API circuit-boards, but I had also included a message making mentions of how I could easily improve upon the general layout design of each PCB at NO ADDITIONAL COST!!! His response??? ..... NOPE!!! "DESIGN MY API PCB'S EXACTLY AS THEY ARE"!!!
So.....I did. Unfortunately, for him.....since he lives in Florida, the humidity down there got to his "New/Old" PCB's and eventually made them all rather nasty!!!
>> SO, KIDS!!! -- The lesson today here is.....when having PCB's fabricated in today's world, just go ahead and have a soldermask placed onto your designs. The cost of having a soldermask on PCB's today is basically "invisible" compared to what they used to cost some 40+ years ago. >> FABRICATE PCB's WITHOUT USING A SOLDERMASK AT YOUR OWN PERIL!!! <<
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