PCBs as Front Panels ?

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Lolo73
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Re: PCBs as Front Panels ?

Post by Lolo73 » Sat Mar 14, 2020 2:37 am

EATyourGUITAR wrote:
Fri Mar 13, 2020 3:56 pm
I no longer use pcbway for non-panel PCB. I use JLC now. If the JLC PCB panels look that good I may not be using pcbcart.com for panels either. Everything JLC now. As I said before, there were a lot of problems with white silkscreen from PCBway. more than one order was bad.
At the moment I'm using pcbway, but I already had a silkscreen problem... they gave me cash back when I send them a picture of the bad panels. I'll try JLC for my next batch so I'll be able to compare.

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Re: PCBs as Front Panels ?

Post by rsholmes » Sat Mar 14, 2020 8:56 pm

Here's my first front panel, from JLCPCB.

(The apparent streaking in the black area at the bottom is light reflecting from the PCB texture. In person, especially head on, it looks better.)
IMG_20200313_160546.jpg
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Re: PCBs as Front Panels ?

Post by indigoid » Sun Mar 15, 2020 5:58 am

so is that a black soldermask with white silkscreen? or white with black silkscreen? or something else"?

I use the top copper layer with ENIG finish instead of silkscreen on my panel PCBs because it's done with a photographic process and is always smooth and doesn't look pixel-y

Here's one I did recently with OSHPark's black substrate / clear soldermask option to see what it would look like. I foolishly did a top copper pour on this one too
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Re: PCBs as Front Panels ?

Post by EATyourGUITAR » Sun Mar 15, 2020 7:58 am

rsholmes wrote:
Sat Mar 14, 2020 8:56 pm
Here's my first front panel, from JLCPCB.

(The apparent streaking in the black area at the bottom is light reflecting from the PCB texture. In person, especially head on, it looks better.)

IMG_20200313_160546.jpg
I just changed my mind. you can see the dot matrix printer resolution. you can see the unwanted streaking. this is not the worst I have seen but it is definitely not something that makes me want to place an order. someone else had much better results from the same supplier so there is some variability.
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Re: PCBs as Front Panels ?

Post by KSS » Sun Mar 15, 2020 12:33 pm

EATyourGUITAR wrote:
Sun Mar 15, 2020 7:58 am
someone else had much better results from the same supplier so there is some variability.
Expect this to be the norm and not the exception. Re-purposing PCB fab to panel duty is always going to have to deal with the fact that PCBs are not graded for 'optics' beyond general readability. This also means scuffs, scratches, and other non-electrical or readability issues are not going to be seen by the fab house as defects. You can do your best to try and get them to see it your way, and some fabs may be better than others. Expect that will become an ongoing fight, with many 'fails' along the way.

But as long as their main focus is making PCBs for PCB use, your panel goals are going to be secondary to them. And as time goes on, the probability of graphics getting better rather than worse is not likely. In the PCB fab world, speed is king. And that means the direct-to-PCB printimg now used for silkscreening is going to get pushed harder and harder for speed. With just enough readability to keep the PCB orders coming in. Your panel PCBs are very small fish in a very big ocean.

This favors both using the ENIG gold for labels with soldermask as background, and the texturing shown in that panel using hatching.

I look forward to seeing how the plain copper with clear solder mask holds up over time.

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Re: PCBs as Front Panels ?

Post by EATyourGUITAR » Sun Mar 15, 2020 1:18 pm

I worked at a company that makes conformal coating for PCB. This was a UV activated coating. Although the formula we used was not conducive to clear. We were making high opacity coatings while I was there. So maybe there is a chance this clear coating is UV activated and also a chance it isn't. It could be enamel. The PCB fabs advertise it for the purpose of debugging prototypes and nothing else. I didn't see any claims about longevity so maybe they didn't even design for that at all. Exposure to high intensity UV for 1 week should tell us something about degradation of this clear coating. You can do this if you have access to UV sterilization at work. Maybe a t-shirt factory has UV curing equipment. The temperature test is pointless since it is already spec. Contamination from other chemicals used in the manufacture of PCB is unlikely. Everything is clean and PH neutral at the time when conformal coating is added.
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Re: PCBs as Front Panels ?

Post by rsholmes » Sun Mar 15, 2020 9:46 pm

EATyourGUITAR wrote:
Sun Mar 15, 2020 7:58 am
rsholmes wrote:
Sat Mar 14, 2020 8:56 pm
Here's my first front panel, from JLCPCB.

(The apparent streaking in the black area at the bottom is light reflecting from the PCB texture. In person, especially head on, it looks better.)

IMG_20200313_160546.jpg
I just changed my mind. you can see the dot matrix printer resolution. you can see the unwanted streaking. this is not the worst I have seen but it is definitely not something that makes me want to place an order. someone else had much better results from the same supplier so there is some variability.
The "streaking" is a light artifact, not seen in actuality. I don't see "dot matrix printer resolution". I do see the PCB substrate texture.

Is this what I would use for a panel on a module I'd be trying to market for top dollar? Of course not. Does it look good enough for my DIY synth? I think it does.

Would it be worth spending about three times as much to get it done at a different PCB fab house that might produce better results? Or, I dunno, maybe six times as much at Front Panel Express? Not to me it wouldn't.

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Re: PCBs as Front Panels ?

Post by indigoid » Mon Mar 16, 2020 6:48 am

EATyourGUITAR wrote:
Sun Mar 15, 2020 1:18 pm
The PCB fabs advertise it for the purpose of debugging prototypes and nothing else. I didn't see any claims about longevity so maybe they didn't even design for that at all. Exposure to high intensity UV for 1 week should tell us something about degradation of this clear coating. You can do this if you have access to UV sterilization at work. Maybe a t-shirt factory has UV curing equipment. The temperature test is pointless since it is already spec. Contamination from other chemicals used in the manufacture of PCB is unlikely. Everything is clean and PH neutral at the time when conformal coating is added.
I think I have spares of those boards. Happy to send them over if you're interested in conducting the UV experiment?
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Re: PCBs as Front Panels ?

Post by EATyourGUITAR » Mon Mar 16, 2020 10:26 am

I no longer have access to UV destructive testing equipment since I no longer work there. I don't think my school has anything UV but I'm not in biotech so I don't know. this was more to answer a question. I don't use clear coating on my PCB so it really doesn't matter to me. I was simply suggesting that if someone wants to know "how long it holds up with time" they can probably do a simple test for free maybe.
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Re: PCBs as Front Panels ?

Post by EATyourGUITAR » Mon Mar 16, 2020 10:28 am

rsholmes wrote:
Sun Mar 15, 2020 9:46 pm
Would it be worth spending about three times as much to get it done at a different PCB fab house that might produce better results? Or, I dunno, maybe six times as much at Front Panel Express? Not to me it wouldn't.
I can understand your position completely. I am not trying to tell other people how they spend money. my goal is to sell things and keep 1 of everything for my own collection. I would not want to present something with defects to one of my customers since I feel like I should be the one who curates that stuff out while I hedge the cost of R&D.
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Re: PCBs as Front Panels ?

Post by NS4W » Tue Mar 17, 2020 2:39 pm

I'm getting into KiCad and have learnt a lot from this thread - thank you all! :tu:
I want to make a panel that take advantage of the different layers we have available, for example like this beautiful Mannequins PCB:
Image

Sometimes the copper looks coppery and other times silver or gold. Where/how do you choose this?

Also, will holes automatically get copper plated?

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Re: PCBs as Front Panels ?

Post by elmegil » Tue Mar 17, 2020 2:41 pm

whether holes are plated or not depends on which gerber they are in. The "npth" (not plated through) file has holes that are not going to be plated.

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Re: PCBs as Front Panels ?

Post by NS4W » Tue Mar 17, 2020 2:58 pm

elmegil wrote:
Tue Mar 17, 2020 2:41 pm
whether holes are plated or not depends on which gerber they are in. The "npth" (not plated through) file has holes that are not going to be plated.
Ok, I cannot put my holes in the edge cuts layer?

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Re: PCBs as Front Panels ?

Post by elmegil » Tue Mar 17, 2020 3:48 pm

I suspect that depends on the guidelines from the particular fab.

yeah, I would expect edge cuts shapes to also not be plated. But I wouldn't use them for "holes" unless we're talking > 1/2"

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Re: PCBs as Front Panels ?

Post by NS4W » Tue Mar 17, 2020 4:26 pm

Ok. What about bleed? When doing graphics on paper its normal to leave a bit of the design running outside the cutting marks in order to make sure the finished print is going all the way out to the edges, if I want to fill the PCB with white using the top silk layer does it matter if the graphic is going outside edge cuts? Will that just be ignored or mess up ?

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Re: PCBs as Front Panels ?

Post by EATyourGUITAR » Tue Mar 17, 2020 4:30 pm

I don't think you will need to worry about that. alignment is much more controlled with PCB manufacturing. it is repeatable +/- 0.01in. the fab will likely modify the silkscreen layer and the copper layers so that nothing is within 0.01in of the edge unless you are ordering cards with edge connectors then the copper goes all the way to the edge.
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Re: PCBs as Front Panels ?

Post by elmegil » Tue Mar 17, 2020 4:44 pm

When you generate the gerbers, KiCad will clip any silk screen layers etc anyway. I have periodically had groundplane pours that exceeded the bounds of the edge cuts, never had any issues.

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Re: PCBs as Front Panels ?

Post by KSS » Tue Mar 17, 2020 4:56 pm

NS4W wrote:
Tue Mar 17, 2020 4:26 pm
Ok. What about bleed? When doing graphics on paper its normal to leave a bit of the design running outside the
The equivalent of bleed in graphic design is set up in PCB design using your design rules. Copper pours, soldermask, screenprint, and paste leyers all have some 'bleed' equivalencies.

You can see some of these in effect in the PCB you posted. Where for example the copper layer stops at the raw pcb, with solder mask over both bare bd and copper pour. With ENIG trace as a graphic line. Bare bd to no copper under solder mask, then to a gold enig plated trace and finally the darker green of the soldermask over the copper pour.

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Re: PCBs as Front Panels ?

Post by kriaction » Wed Mar 18, 2020 6:12 pm

I am glad I found this thread, there are a lot of great panels and the results are very promising.
I am currently working on two large faceplates (40x60cm or 15.7x23 inches) using inkscape and svg2shenzen to export the layers in Kicad. The file management and creation has been surprisingly easy and versatile, particularly at the inkscape side.
I made a couple of tests using FR4 and matte black soldermask, sent the gerbers to JLC PCB and they came out pretty nicely. :sb:
IMG_20200318_221545_copy.jpg
IMG_20200318_221538_copy.jpg
For the two large faceplates I am going to rely on another chinese manufacturer -Multitech PCB- that can produce them using 2mm aluminum. I'll post the results when they arrive home, hopefully I can place the order by the end of the month. :hyper:
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Re: PCBs as Front Panels ?

Post by mrand » Sat Mar 21, 2020 11:11 am

NS4W wrote:
Tue Mar 17, 2020 2:39 pm
Sometimes the copper looks coppery and other times silver or gold. Where/how do you choose this?
I didn't see a reply to this yet, and have been wondering the same. Furthermore, I'm curious if anyone has tried any chemical washes on their exposed copper to achieve a patina or oxide layer.
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Re: PCBs as Front Panels ?

Post by KSS » Sat Mar 21, 2020 5:40 pm

mrand wrote:
Sat Mar 21, 2020 11:11 am
NS4W wrote:
Tue Mar 17, 2020 2:39 pm
Sometimes the copper looks coppery and other times silver or gold. Where/how do you choose this?
I didn't see a reply to this yet, and have been wondering the same. Furthermore, I'm curious if anyone has tried any chemical washes on their exposed copper to achieve a patina or oxide layer.-Colin
0) Copper is obviously just the plain copper. Likely to tarnish, and may even be hard to get because-
Most PCB fab use some kind of finish solution or plating to prevent the raw copper from being an issue. These present as differing levels of silver or gold

1) ENIG is shiny gold. Electro Nickel Immersion Gold

2) ENIG is most popular gold for general pad plating. Edge connector finger plating is thicker and will assuredly cost more. But will have a deeper, richer gold color too. Might be hard to get a clear understanding of what you want across to the fab if using foreign fab dueto language misinterpretations. They're used to using this on fingers, not artistically!

3) Whitish powdery silver is a time sensitive material. Many different formulas.

4) Another whitish silver is tin plating. Usually immersion tin, and possible for DIY after receipt from fab. Immersion tin is very susceptible to tarnishing -showing fingerprints as dark elements across the plating. Could be used for artistic effect, but will change over time.

5) Bright silver is usually a HASL Hot Air Solder Level-ed -ing. This may be either RoHS or not. AKA lead-free or not. The color will look different between the two.

Many or all of these are subject to change in appearance over time. Avoid the powdery silverish coating. it's a flux designed to aid soldering and has a short shelf life. ENIG also has a short shelf life if soldering is planned.

Then you have the option of getting a different hue or tone by using these with or without solder mask. Color and opacity of solder mask very important to effective results.

And finally -as seen in panel above- any or all of these could be over copper pour or alone on bare PCB substrate. Substrate color can be different from different fabs, and also from the same fab since its based on who made the copper clad originally. And suppliers and batches change.

In answer to your second question, have over-plated copper and also with various chemical washes over copper, but not for PCB use. Again you will be happiest if you assume the overall effect will change over time. Even with clear coatings designed to prevent it.

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Re: PCBs as Front Panels ?

Post by indigoid » Sat Mar 21, 2020 6:48 pm

kriaction wrote:
Wed Mar 18, 2020 6:12 pm
I made a couple of tests using FR4 and matte black soldermask, sent the gerbers to JLC PCB and they came out pretty nicely. :sb:
The silkscreen looks pretty streaky here too

Also more than once I've had silkscreen smear with too much handling. This more than anything else discouraged me from using it on panels. Maybe it was just a shit PCB fab and this isn't normal, but the synths we build tend to be fairly tactile instruments and if it is normal, I wonder how long it would take in normal use
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Re: PCBs as Front Panels ?

Post by kriaction » Sun Mar 22, 2020 2:17 pm

indigoid wrote:
Sat Mar 21, 2020 6:48 pm
kriaction wrote:
Wed Mar 18, 2020 6:12 pm
I made a couple of tests using FR4 and matte black soldermask, sent the gerbers to JLC PCB and they came out pretty nicely. :sb:
The silkscreen looks pretty streaky here too
Honestly it is in a couple of spots, sharp and full in others. It was looking fine to me because it was a real step up from the methods I tried, definitely more professional looking than a marker or etching.
indigoid wrote:
Sat Mar 21, 2020 6:48 pm

Also more than once I've had silkscreen smear with too much handling.
WOW, really? I've read people advise to spray clear coat on it, maybe this is the reason why.

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Re: PCBs as Front Panels ?

Post by mrand » Sun Mar 22, 2020 2:42 pm

KSS wrote:
Sat Mar 21, 2020 5:40 pm
[...]
Thanks, KSS, for your in-depth reply!
Last edited by mrand on Sun Mar 22, 2020 2:44 pm, edited 1 time in total.
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Re: PCBs as Front Panels ?

Post by mrand » Sun Mar 22, 2020 2:43 pm

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