How fragile are the PCBs generally?

orc123

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Hi,

I have quite big headaches about proper PCB handling. :)
Please, can you give some general advices for this topic?

a) how to hold the PCB in your hands properly? I think, that the best way is to hold it in both hands by the external board edges, is that right?

b) When you want to inspect the bottom (solder) side of PCB, how you do it without laying it down to the bulking out components parts? Do you use some PCB holder to reverse and inspect it?

c) if you have a game with 2 (or more) boards, does it not bend over itself only by its weight by some time?.
Are the game boards (material) itself quite firm? Do you not break off a piece of the board with "normal" handling? Its terrible to hear how it creaks and bends a bit when you hold it firmly and connect the harness.

d) is the frequent (lets say 3 times a week) JAMMA harness connection/disconnection (because of PCB exchange) a problem? Does not cause the connector damage (rub off) soon?

Thanks very much for any reply.
 
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The biggest risk when handling PCB's is ESD, also known as what happens when you touch a door handle after walking across a carpeted room wearing socks. Zapping a PCB with a static shock can and often will damage it. The fancy silvery bags that you often see PCB's stored in are, I believe, slightly conductive to keep the potential across the whole board equal and therefore prevent any ESD buildup.

The absolute best way to handle a PCB is at an ESD-safe workstation, or at the very least while wearing a grounded bracelet. If you don't have a grounded bracelet or are too lazy to be bothered to wear it, touch something grounded before handling a sensitive component, like a water pipe.

That being said, the chance of accidentally zapping a board is pretty minimal, but it doesn't hurt to be safe.

a) how to hold the PCB in your hands properly? I think, that the best way is to hold it in both hands by the external board edges, is that right?

Probably. The board itself is non-conductive so there will be less risk if you avoid touching the components.

b) When you want to inspect the bottom (solder) side of PCB, how you do it without laying it down to the bulking out components parts? Do you use some PCB holder to reverse and inspect it?

You can use a PCB vise or you can just lay it down and be careful. Most of them are pretty sturdy, so if you set it down on a few chips or capacitors, you don't run a huge risk of damaging anything. If you're concerned and you don't have a PCB vise, a few non-conductive blocks under the corners would also work.

c) if you have a game with 2 (or more) boards, does it not bend over itself only by its weight by some time?.
Are the game boards (material) itself quite firm? Do you not break off a piece of the board with "normal" handling? Its terrible to hear how it creaks and bends a bit when you hold it firmly and connect the harness.

Multi-board stacks usually have standoffs or other hardware to keep the boards together. I've never seen a warped PCB, but I imagine it could happen if a multi-board stack was incorrectly mounted in a cabinet for many years, and the inside of the cabinet was fairly warm. Overall, they're pretty sturdy. Most of the creaking that you hear is any socketed chips moving in their sockets. The connector itself also creaks a little when you attach it.

It takes a lot of effort to break/chip a PCB. Normal handling will not damage a board. Dropping one from several feet directly on a corner may damage it, but that's about the only "normal" way I can imagine seeing one broken. Physical damage to PCB's is pretty rare (not counting cut traces).

d) is the frequent (lets say 3 times a week) JAMMA harness connection/disconnection (because of PCB exchange) a problem? Does not cause the connector damage (rub off) soon?

The copper traces themselves on the board are actually pretty thick. You're not likely to "rub off" an edge connector.
 
Most PCBs are pretty resistant to being damaged unless you do something like drop them. If they can survive being run through the dishwasher for cleaning, you do about anything reasonable with them if you are careful.
 
Just my opinion, the ESD thing is way overstated.

They teach you some things in school, you learn other things from experience. From my experience, ESD isn't much of a problem when it comes to arcade game pcb's. When was the last time you grabbed a gameboard and shocked the shit out of it with your fingers? Come on people.

The #1 way to damage a PCB is to stack it on top of (or under) a bunch more of them. You'll scratch a trace or snap a corner, or something.

MAY THE DRAMA BEGINNNNNN.
 
Just my opinion, the ESD thing is way overstated.

They teach you some things in school, you learn other things from experience. From my experience, ESD isn't much of a problem when it comes to arcade game pcb's. When was the last time you grabbed a gameboard and shocked the shit out of it with your fingers? Come on people.

The #1 way to damage a PCB is to stack it on top of (or under) a bunch more of them. You'll scratch a trace or snap a corner, or something.

MAY THE DRAMA BEGINNNNNN.

It's a much bigger issue with newer electronics since they are made like shit. The stuff from BITD holds up far better. Maybe because it's simpler or maybe because it was simply better quality. At any rate I've seen many an arcade game PCB covered in the nastiest shit imaginable and exposed to moisture, heat, cold and who knows what else and still fire up when plugged in. I think the batteries that were put on the boards generally cause more damage than any outside element your likely to encounter.
 
Just my opinion, the ESD thing is way overstated.

They teach you some things in school, you learn other things from experience. From my experience, ESD isn't much of a problem when it comes to arcade game pcb's. When was the last time you grabbed a gameboard and shocked the shit out of it with your fingers? Come on people.

The #1 way to damage a PCB is to stack it on top of (or under) a bunch more of them. You'll scratch a trace or snap a corner, or something.

MAY THE DRAMA BEGINNNNNN.

I'm of the same basic opinion here. I don't really take any ESD precautions, except maybe if I know I'm going to be handling a CMOS IC directly, and it's very dry (which is rare in Florida), I might touch something grounded first.

PCBs are fairly robust overall. Try not to drop them. Don't stack them bare. I store them in (free) USPS or FedEx cardboard boxes to prevent board-on-board violence.
 
ESD sensitivity is not about 'they don't make things as good anymore'. It's about the increasing complexity and density in the electronics.

Component operating voltages are far lower, feature size in silicon has increased substantially. The smaller the feature size and increased density allows high voltage (static) to more easily damage features inside the chip.

I deal with modern electronics extensively and ESD is a real issue. It is often overstated, but it DOES happen. The real issue is that most people encounter a damaged board/component and don't realize it was ESD that actually caused the damage.
 
Thanks a lot for the all hints.

I know of the ESD danger and also always at least touch with both hands something big metal grounded like a central heating or so before touching the PCB.
I also red that it is dangerous especially for the ICs (like RAM chips and so one).
Some plastic materials can accumulate a lot o ESD for sure - I had some really sparking T-shirts and sweeters :) and also I have got many ESD shocks/hits when touching the doors.
The question is, what you consider to be "really ESD sensitive, modern, low voltage and high integration" technology.

I was especially affraid of the mechanical PCB damage when (re)moving the board, laying it onto the wooden desk, holding it firmly and puting the harness on and off - but as you say, the boards material is probably quite sturdy and does not break during such common manipulation. Now I can be more cool. :-D
 
Handling a RAM module or CPU is going to be the most ESD sensitive parts you would likely encounter. A lot of that is because they are basically raw components. (RAM modules are basically chips with a connector).

Once the parts are on a board with the rest of the circuits connected the potential for ESD damage does decrease (but is not eliminated).

Physical damage of the board from casual handling, laying on a surface, is pretty much a non-issue. Components themself are pretty solid physically.
 
As far as newer stuff goes, I'd say that would start around the late 90's, especially once supply voltages dropped below 3.3V. Most arcade boards are excluded from this, but again, it never hurts to be safe.
 
newer JAMMA stuff no great worries. The ones I really watch for are the old ATARIs. Long, thin boards that when flexed will break traces (millipede, centipede,missle command, Pole position, ect). Lots of these have been mishandled and ruined over the years.
 
A very easy way to reduce the overall risk of ESD damage is to use a humidifier during the winter. It may also improve game performance. If the air is really dry in the winter, my Pac-Man and Ms. Pac-man will sometimes reset when the coin door or CP are touched, especially if you receive a zap at the time.

Stacking PCBs directly on top of each other is probably a bad idea. Mine are bubble wrapped and stacked in a box. Anti-static bags followed by bubble wrap is probably the best way to go. Or you could build your own custom storage rack as one of the guys here did.
 
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PCB durability - does (air) humidity matter?

Hi, thanks very much for the information.
And please, what about the air humidity? Does it really matter?

I am asking, because currently I had to move my stuff into the room, where my wife had to do also some ironing and is also not very far from bathroom and the vapour can rise humidity. I ventilate the room of course, but I still have some headaches :) Is some home air humidity (from ironing, bathroom, etc.) big problem for the PCB/electronics durability?

It is in this case better to cover stuff with something and put PCBs in plastic bags (for humididy protection) or better not?
I am a bit affraid of some water condensation inside the bag or something like that when I cover it with something.
Thanks for opinion :)
 
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Humidity itself is not a concern. Condensation is though.
 
A very easy way to reduce the overall risk of ESD damage is to use a humidifier during the winter. It may also improve game performance.
thanks, but wait, lol, this is absolutly against mine humidity danger theory :) is that really safe? I was thinking of some silicon to reduce air humidity instead.
 
Humidity itself is not a concern. Condensation is though.
well so in this case its probably better not to cover things into bags (because of possible condensation) and leave it "open air". Then humidity comes and leaves. Still the condensation should mostly occure at very high humidity level or on the cold objects.
 
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I wore out my Jamma Harness on my test bench from plugging so many PCBs in it to test them. I had to recrimp on all new connectors. I have also had this same connector for 4 years and have gone through 500+ PCBs on it. It sucked testing boards as having issues they learning it was the harness. I would lose a color so it would only have red and blue, or the sound may or may not work. Everything was great again once I but the new connectors on.

-Jake
 
As far as newer stuff goes, I'd say that would start around the late 90's, especially once supply voltages dropped below 3.3V. Most arcade boards are excluded from this, but again, it never hurts to be safe.
thanks for the information.
so the older 80ties boards seems to not be as ESD sensitive as the late 90ties, right?
The ESD is most dangerous/often in direct physical contact (by touching the chips by hand when you are charged) or without direct contact (transfered by air in certain distance)?
I red somewhere, that the safe distance is approx. 10-12 inches for static charged thing.
What about the right wear? I think the 100% cotton wear is quite ok for normal occasional use, not generating too much static, am I right?
Basicly I am very scared about the "latent" ESD damage :). If I understand it right, some component can be partialy damaged and board will still work (temporary) fine. Is it really so bad?
 
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