I have on occassion used "liquid silver", a product sold by jeweller suppliers or used by people who sell antiques and such, which is a solution of some silver salt (smells faintly of ammonia) .
You wipe it on most any metal, specially copper
or brass, and it deposits a thin silver layer.
Maybe it's something similar.
The one I used worked very well.
Only problem is, it was *real* silver and darkened in a couple of months , if in a humid place.
You wipe it on most any metal, specially copper
or brass, and it deposits a thin silver layer.Maybe it's something similar.
The one I used worked very well.
Only problem is, it was *real* silver and darkened in a couple of months , if in a humid place.
Moos - you aren't the only reader of the thread - as I said you know your strengths, interests - others may benefit for other perspectives
I find home PCB making a added complication, can put too much in the way for some
so I feel talking up hand prototyping techniques, squashing the uninformed idea that only PCB can give good electrical performance is a responsible contribution
I did hand fab hobby PCB in the 80's - there simply weren't today's options for cheap, professional fabbed PCB
I really like PTH, Solder Mask, part desinator Slik Screen, tinned pads - in fact some of my "hobby" boards have been 4-layer
for me the circuit design is my creation - and this does include the build, either (or both) the hand prototyping, full PCB layout for electrical performance
why home fab an inferior capability, tolerance PCB when I can have one precisely made to my specification
I don't home fab semis, op amps or microprocessors other electrical parts
I don't see how working circuits either on dead bug protos or Pro manufactured PCB detract from my sense of "ownership", accomplishement
I find home PCB making a added complication, can put too much in the way for some
so I feel talking up hand prototyping techniques, squashing the uninformed idea that only PCB can give good electrical performance is a responsible contribution
I did hand fab hobby PCB in the 80's - there simply weren't today's options for cheap, professional fabbed PCB
I really like PTH, Solder Mask, part desinator Slik Screen, tinned pads - in fact some of my "hobby" boards have been 4-layer
for me the circuit design is my creation - and this does include the build, either (or both) the hand prototyping, full PCB layout for electrical performance
why home fab an inferior capability, tolerance PCB when I can have one precisely made to my specification
I don't home fab semis, op amps or microprocessors other electrical parts
I don't see how working circuits either on dead bug protos or Pro manufactured PCB detract from my sense of "ownership", accomplishement
I spray clear lacquer on my finished boards to protect the copper. It works very well, and I can solder over it no problem. Some say it even acts as a mild flux, but I have no evidence for that either way. All I can say is that it certainly doesn't hinder solder-ability.
Chemical-wise, I've used both Ferric Chloride and HCl+H202 (40% strength) +H20 (all three in equal parts), and gotten good results with both. Ferric needs to be heated or else it takes forever to etch. HCl+H2O2 etches quicker even if it's cold, but it's still best to be heated. I've etched large-ish boards VERY fast with heated HCl in a tank with a bubbler, but yes, it's nasty stuff... goggles and gloves are mandatory. Watch out for the Chlorine fumes too!
For casual home use, Ferric is the better choice because of safety (as has been mentioned). I've been using Ferric lately since I've moved to an apartment and don't have a garage I can use nasty chemicals in.
Photofab isn't that hard to do at home with a little practice, and it doesn't cost much for chemicals. The presensitized boards are cheap too. I use that technique with larger boards, but for smaller ones I just iron-on, either with Press n' Peel Blue, or if I'm cheap, any random paper can be used in a pinch.
By far, the most difficult and time consuming part of the process is drilling the holes. But even that isn't too bad with some practice.
Chemical-wise, I've used both Ferric Chloride and HCl+H202 (40% strength) +H20 (all three in equal parts), and gotten good results with both. Ferric needs to be heated or else it takes forever to etch. HCl+H2O2 etches quicker even if it's cold, but it's still best to be heated. I've etched large-ish boards VERY fast with heated HCl in a tank with a bubbler, but yes, it's nasty stuff... goggles and gloves are mandatory. Watch out for the Chlorine fumes too!
For casual home use, Ferric is the better choice because of safety (as has been mentioned). I've been using Ferric lately since I've moved to an apartment and don't have a garage I can use nasty chemicals in.
Photofab isn't that hard to do at home with a little practice, and it doesn't cost much for chemicals. The presensitized boards are cheap too. I use that technique with larger boards, but for smaller ones I just iron-on, either with Press n' Peel Blue, or if I'm cheap, any random paper can be used in a pinch.
By far, the most difficult and time consuming part of the process is drilling the holes. But even that isn't too bad with some practice.
This forum is called "DIY audio". "DIY" means "Do It Yourself". It does not mean "I am a rich man - I can afford to pay someone else to do it for me".
Some of us are not "employed in 1st world country". Perhaps your "lunch money" is enough to pay my rent. If so , good for you, but please allow for the possibility that some people may actually want to do it themself.
I have on occassion used "liquid silver", a product sold by jeweller suppliers or used by people who sell antiques and such, which is a solution of some silver salt (smells faintly of ammonia) .
You wipe it on most any metal, specially copper
Maybe it's something similar.
The one I used worked very well.
Only problem is, it was *real* silver and darkened in a couple of months , if in a humid place.
in my case, i use clear plastic varnish on the boards to prevent tarnish....
the drilled pc board, i clean with scothbrite pads with "Ajax" powder cleanser on the copper side, wet wiping till copper turns reddish and black spots gone, rinsing on running water and drying, once dried up, coating with clear plastic varnish....this is labor intensive but ensures that boards will never oxidize, aid in soldering also...
I'm not keeping anybody from reading any other posts here - just giving a different pespective that is not being presented otherwise
and my point that various hand prototyping techniques can give superior electrical performance should be welcomed by poeple with less money, more time
I have worked professionally designing electronics for industrial and scientific instrumentation
I can assure you that many test fixtures, calibration circuits on the production floor were point-to-point or other hand wired proto technique
until the recent decade's cheap PCB fab services it would cost US$k for even one PCB - and a 5 figure CAD system and sw for layout
free sw on cheap computers, internet access to worldwide manfacturers with cheap PCB fab services change the equation for many
and my point that various hand prototyping techniques can give superior electrical performance should be welcomed by poeple with less money, more time
I have worked professionally designing electronics for industrial and scientific instrumentation
I can assure you that many test fixtures, calibration circuits on the production floor were point-to-point or other hand wired proto technique
until the recent decade's cheap PCB fab services it would cost US$k for even one PCB - and a 5 figure CAD system and sw for layout
free sw on cheap computers, internet access to worldwide manfacturers with cheap PCB fab services change the equation for many
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One shot
C'mon jcx, admit that veroboard and 'dead-bug' are error prone. Once you get those chips stuck on there upside down, the likelihood of a wiring error is multiplied. Nobody said that they had inferior electrical performance, you read that into what was written because you wanted a hook to hang your defence on.
What I said was 'There's just no way to get a comparable result as quickly.'
Comparable in terms of freedom from error, ease of construction and finished appearance, plus when it comes right down to it some of the stuff I build does operate at RF, and I'll put up one of my boards in terms of predictable performance and low strays against any dead bug, veroboard or point-to-point device you care to produce.
The whole world doesn't operate at audio frequency.
When I come to think of it too, a lot of my stuff has microprocessors, address and data busses. You can't be fiddling about with point-to-point, to say nothing of the fact that you'd never get the stuff to fit.
So you're not 'squashing the uninformed idea that only PCB can give good electrical performance' unless you're talking about squashing the straw man you set up yourself.
You're just beating one of your hobby-horses to death.
One shot.
When I used to do darkroom photography 'one-shot' developing of colour prints made this process popular.
D76 used to be the black/white fine-grain developer of choice for many professionals, it was a mainstay in darkrooms. The problem was that it was made up in a large quantity and used repeatedly. Once you'd used it you poured it back into the bottle. The development time extended. The problem was knowing how much it had extended.
One-shot developers were more popular with amateurs. You made up the developer, used it, then threw it away. This had a second advantage in that you could make up hot water to the right temperature, dilute the developer, and you'd be in business in no time. Later I learned to use a microwave oven to bring things up to temperature. With a bit of practise, knowing the quantity, you could just measure the current temperature and dial in how many seconds to reach the temperature you wanted.
This is all by the way.
When making boards in quantity a bubble-etch tank or spray etcher is economic and sensible.
When making boards on a one-off basis, make up enough etchant to etch the board. You can actually calculate this, because packed etchant states how many square inches it will etch. I've done so many boards I just guesstimate. Don't throw the etchant away, store it and dispose of it responsibly, it's highly inimical to marine life and many other forms of life.
C'mon jcx, admit that veroboard and 'dead-bug' are error prone. Once you get those chips stuck on there upside down, the likelihood of a wiring error is multiplied. Nobody said that they had inferior electrical performance, you read that into what was written because you wanted a hook to hang your defence on.
What I said was 'There's just no way to get a comparable result as quickly.'
Comparable in terms of freedom from error, ease of construction and finished appearance, plus when it comes right down to it some of the stuff I build does operate at RF, and I'll put up one of my boards in terms of predictable performance and low strays against any dead bug, veroboard or point-to-point device you care to produce.
The whole world doesn't operate at audio frequency.
When I come to think of it too, a lot of my stuff has microprocessors, address and data busses. You can't be fiddling about with point-to-point, to say nothing of the fact that you'd never get the stuff to fit.
So you're not 'squashing the uninformed idea that only PCB can give good electrical performance' unless you're talking about squashing the straw man you set up yourself.
You're just beating one of your hobby-horses to death.
One shot.
When I used to do darkroom photography 'one-shot' developing of colour prints made this process popular.
D76 used to be the black/white fine-grain developer of choice for many professionals, it was a mainstay in darkrooms. The problem was that it was made up in a large quantity and used repeatedly. Once you'd used it you poured it back into the bottle. The development time extended. The problem was knowing how much it had extended.
One-shot developers were more popular with amateurs. You made up the developer, used it, then threw it away. This had a second advantage in that you could make up hot water to the right temperature, dilute the developer, and you'd be in business in no time. Later I learned to use a microwave oven to bring things up to temperature. With a bit of practise, knowing the quantity, you could just measure the current temperature and dial in how many seconds to reach the temperature you wanted.
This is all by the way.
When making boards in quantity a bubble-etch tank or spray etcher is economic and sensible.
When making boards on a one-off basis, make up enough etchant to etch the board. You can actually calculate this, because packed etchant states how many square inches it will etch. I've done so many boards I just guesstimate. Don't throw the etchant away, store it and dispose of it responsibly, it's highly inimical to marine life and many other forms of life.
@jcx: I do value your insight, and figured you must be in the industry in one way or another.
Your initial post said you didn't understand why a hobbyist would do this, or suggest it to another. I was just giving you the answer.
I think there are various levels of DIY at play here, and everyone has their own thing. There are guys buying prefabbed pcbs for amps the didn't design. I have no clue what the fun is in that, but to each his own. There are guys like you who love to design, and desire for their design to be on the same PCB quality that a commercial device would get. The fact that you are in the industry probably contributes to this. Once you've used pro boards at work, I imagine the hassle of a DIY board at home that looks less professional for the degree of work involved would be hard to sell to yourself.
Then theirs guys like me, who want to design, but also just want the hands on enjoyment of building the thing. Sure, there's a pride thing, but the process is just as much a draw. Of course I can't do my own ICs, or passives for that matter, but no one's calling for complete purity of the DIY notion. There are obvious limits!
Your initial post said you didn't understand why a hobbyist would do this, or suggest it to another. I was just giving you the answer.
I think there are various levels of DIY at play here, and everyone has their own thing. There are guys buying prefabbed pcbs for amps the didn't design. I have no clue what the fun is in that, but to each his own. There are guys like you who love to design, and desire for their design to be on the same PCB quality that a commercial device would get. The fact that you are in the industry probably contributes to this. Once you've used pro boards at work, I imagine the hassle of a DIY board at home that looks less professional for the degree of work involved would be hard to sell to yourself.
Then theirs guys like me, who want to design, but also just want the hands on enjoyment of building the thing. Sure, there's a pride thing, but the process is just as much a draw. Of course I can't do my own ICs, or passives for that matter, but no one's calling for complete purity of the DIY notion. There are obvious limits!
A typical industrial installation uses a polythene tank with a heater (like an industrial aquarium heater) and a perforated tube that runs along the bottom of the tank with an air pump (not unlike an aquarium air pump). Bubbles rising from the tube agitate the solution reducing the overall etch time. Temperature is typically 50 degrees C.
A similar heated tank alongside contains etch resist developer, but without bubbles, the board is washed manually by raising and lowering it into the tank and the time is short enough that the absence of bubbling is of no consequence.
A superior industrial-style installation uses a pump to raise etchant from a heated reservoir. The etchant is sprayed onto the board continuously and drains back into the reservoir under gravity. Etch time can be 1/10 of that of a bubble tank.
Home users frequently adopt photographic developing dishes, I'm fortunate enough to have some still, but for small boards the plastic containers which takeaway food comes in are useable, and no loss if stained by the chemicals, which they frequently are.
A secondary dish of hot water is an aid to maintaining temperature.
A similar heated tank alongside contains etch resist developer, but without bubbles, the board is washed manually by raising and lowering it into the tank and the time is short enough that the absence of bubbling is of no consequence.
A superior industrial-style installation uses a pump to raise etchant from a heated reservoir. The etchant is sprayed onto the board continuously and drains back into the reservoir under gravity. Etch time can be 1/10 of that of a bubble tank.
Home users frequently adopt photographic developing dishes, I'm fortunate enough to have some still, but for small boards the plastic containers which takeaway food comes in are useable, and no loss if stained by the chemicals, which they frequently are.
A secondary dish of hot water is an aid to maintaining temperature.
I've done small boards with ferric in a 2-cup Pyrex measuring cup sitting in a pan of hot water heated on the stovetop. True story.
Trick is to not heat it too much, because some etchant starts to not work as well if it's too hot. I say keep the heat on Low. Sorry, I didn't measure temperatures... didn't have a thermometer handy. I do have a decent liquid thermometer, so maybe next time I'll measure it.
When I was doing alot of HCl etching in a tank with a bubbler, it was heated with one of those immersible aquarium heaters. I just cranked it up all the way.
Trick is to not heat it too much, because some etchant starts to not work as well if it's too hot. I say keep the heat on Low. Sorry, I didn't measure temperatures... didn't have a thermometer handy. I do have a decent liquid thermometer, so maybe next time I'll measure it.
When I was doing alot of HCl etching in a tank with a bubbler, it was heated with one of those immersible aquarium heaters. I just cranked it up all the way.
Would a cheap tupperware or rubbermade food type plastic container work ok?
also how well does various plastics and what not survive this. For instance, I have an airstone connected by surgical tubing to a small pump that I have used to get bubbles in an aquarium. Sounds like the agitation would be good, but would the stone and tubing survive? Its all pretty cheap stuff, so as long as I got more than 3 or 4 boards out of it, I would call it a win.
also how well does various plastics and what not survive this. For instance, I have an airstone connected by surgical tubing to a small pump that I have used to get bubbles in an aquarium. Sounds like the agitation would be good, but would the stone and tubing survive? Its all pretty cheap stuff, so as long as I got more than 3 or 4 boards out of it, I would call it a win.
I've used cheap "Ziploc" brand disposable storage containers before, and they've held up to multiple uses before they needed thrown out.
Most plastics can handle it pretty well, though ferric stains it very easily, that's not really a big deal if you're not using it for anything else. Pyrex glass dishes work great and usually don't stain unless you leave ferric sitting in it for a very long time (like months).
My plastic bubbler tank began to break down after a few years of constant use with HCl.
Most plastics can handle it pretty well, though ferric stains it very easily, that's not really a big deal if you're not using it for anything else. Pyrex glass dishes work great and usually don't stain unless you leave ferric sitting in it for a very long time (like months).
My plastic bubbler tank began to break down after a few years of constant use with HCl.
I don't know about the airstone. Depending on what it's actually made of, it might get eaten. My bubbler tank had perferations in the bottom of it. The tubing should be fine.
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