Make plastic printed circuits with a standard laser cutter-----make money online

today on Applied Science we're going to

talk about plastic printed circuits so

these have been available commercially

for a while but in this video I'm going

to show you a new process tour we can

take a 3d printed part put it in the

laser cutter dip it in some chemicals

and end up with this

this shows a 1/2 millimeter pitch a

leadless part soldered down with o4o to

components and oh you also get plated

through holes for free of course because

we just make the holes in the laser

cutter and this process will plate those

holes so I wanted to show this was more

than just a curiosity this is actually a

pretty functional process and I'm gonna

give you all the details in this video

and then in the second half we're going

to talk about the commercial process how

this is done at scale and you can

actually do a similar thing in the laser

cutter by mixing some copper oxide which

actually makes copper traces without any

plating baths I mentioned copper plating

bats and so let's start talking about

ways that we can get copper to stick to

another object and so one of the most

common ways is to start with a copper

electrode and something that you want to

cover in copper and put both of these

into an acid bath and then run an

electrical current between the two

plates and the copper ions will go

through the solution and coat the other

object with some additives in the

solution the problem is I mean this

requires the object that you want to

plate to be conductive Rank's they're

running an electric current through

there and that's not gonna work for us

because we're starting with a plastic

substrate so there's a whole other kind

of copper plating technology called

electroless copper plating and in fact

it's used quite a bit in the circuit

board industry so this is actually not a

solid piece of copper this is a piece of

circuit board and in the standard

process what you want to do is drill

holes in this thing but then the like

the the through-hole is not plated the

hole with nut will not be conductive and

if we want to make a connection from one

side of the board to the other the

fabrication house that makes these

circuit boards needs to plate the inside

of that hole with copper so this

electroless copper process is used

actually everyday all around the world

to make circuit boards you would think

with such a common process used by you

know probably

thousands of businesses around the world

that the details would be well worked

out unfortunately when it comes to

electroless copper trade secrets rule

everything there are a few patents but

believe it or not there's actually not

even enough information and patents to

really figure out what's going on it

takes a lot of trial and error and I'm

going to give you the condensed version

in this video and give you the exact

measurements that you can hopefully

replicate this the whole idea behind an

electrolysis copper system is to make a

solution full of copper that's just

ready to fall out of solution right so

we've got this beaker here filled up

with the magic liquid and it's right on

the verge of dropping all that copper

out and making metal but the trick is

it's not doing it right like the beaker

is not coated with copper it's just shy

of being to that point where the copper

would fall out so the trick is if we put

an object in here that we want a plate

with copper how do we make the object

different than the beaker and the tanks

and the pumps and everything else you

might have connected to this and the

answer is that we first dip the object

we want to coat in copper in a catalyst

and so that's over here and so the basic

process is to really wash this really

well dip it in the catalyst wash it

again and then dip it into the magic

solution and take it out and you'll have

a copper part you probably guessed that

since this magic solution is right on

the edge of dropping the copper out all

by itself it is pretty unstable so this

this solution here will probably not

last more than a day or two I've

experimented with different formulations

and some are more stable than others but

generally if you want it to run quickly

like in other words you you want your

part to be coated with copper quickly

that means that the bath has to be very

aggressive and in that case it's also

unstable and just won't last very long

on the other hand if you're okay with

going slow you can mix up the bath to be

less aggressive and so it'll be more

stable but it will also plate copper

more slowly if you think about it this

process also requires that the freshly

laid down copper continues the process

right like if we dip this on

did part in the catalyst then dip it in

the bath and it starts to plate because

we have that nice catalyst on there as

soon as that first atomic layer of

copper is laid down we don't want the

process to stop we want this to keep

going ideally forever and so the other

trick is that this bath has to be Auto

catalytic so that all the freshly

deposited copper will continue that

reaction so all these requirements you

know the thing has to be kind of

teetering right on a knife edge it has

to be quick but also stable it has to be

Auto catalytic mean that there's quite a

few requirements placed on the chemical

composition let's talk about what's in

this magic plating bath first we need a

source of copper ions and so in that

case we're going to use copper sulfate

and already if you start searching for

recipes for this you'll run into a

slight problem sometimes the recipe will

call for copper sulfate without saying

whether they're talking about copper

sulfate pentahydrate now it's really the

same chemical it's just that the

pentahydrate means there's some water in

there so if they're calling for two

grams well 2 grams of copper sulfate

anhydrous is different than two grams of

copper sulfate pentahydrate and so at

first it might seem like a you know a

pedants sort of point that's just

annoying but but actually it's

critically important and if you don't

specify it's kind of hard to tell what's

going on so I'm gonna show you the

labels of all the stuff that I use so

that it's completely unambiguous what

I've what I've done here so copper

sulfate pentahydrate 5 grams per liter

potassium sodium tartrate tetrahydrate I

just call this tartrate on my car charts

this is 20 grams per liter

sodium hydroxide 5 grams per liter it

doesn't have to be particularly pure I'm

just using this drain opener

there's no aluminum chunks in here it's

just sodium hydroxide

sodium carbonate 5 grams per liter and

finally a solution of formaldehyde 37%

10 milliliters per liter

another little gotchu is you might hear

the word formal in well formalin is

basically just 37% from aldehyde in

water with maybe a stabilizer in there

and then even more confusingly you might

get a like a 10% formalin solution so a

10% formalin is just 3.7 percent from l

dehyde here's a quick rundown of what's

happening in here chemically obviously

the copper sulfate is the source of the

copper ions that we want to eventually

plate the object the tartrate is a

chelating agent that allows the copper

to dissolve in the water more easily

without the tartrate the copper sulfate

wouldn't dissolve and a high enough

concentration for this thing to be

useful we want the the liquid to hold a

lot of copper the formaldehyde is a

reducing agent and so the formaldehyde

if there were nothing else in here would

cause the copper to just start crashing

out a solution if there was enough of it

basically the copper is going to be

stored in an oxidized state in solution

and then adding the formaldehyde is

going to reduce it and cause it to go

back into copper metal the sodium

hydroxide is just a pH adjuster this

whole process only works at high pH very

high pH in fact about 12 and a half or

13 so we need sodium hydroxide to do

that and the sodium carbonate is a

buffer so the as this process continues

it actually creates its own acid like if

for every molecule of a copper or every

atom of copper deposited there'll be

some amount of acid created and if we

don't do anything about that it's going

to shift the pH of our solution and then

cause the thing not to work well anymore

so the trick with adding sodium

carbonate is that it can absorb some

acid being created by the process and

maintain the pH where it should be so

I've tried a lot of different recipes

and found this one by far to be the best

it's pretty stable it will last for at

least a day or two

and if you stick exactly to these values

you shouldn't have any problems just for

the records I've been doing everything

in 300 ml batches in beakers on stir

plates and typically the way that I mix

this up is to dissolve the tar straight

first then the copper sulfate then the

NaOH the carbonate and finally the

formaldehyde and wait until each one of

these things is dissolved before adding

the next ingredient okay let's talk

about this catalyst solution so here it

is and I've also been mixing this up in

this is actually a 250 ml batch and the

idea here is that we start with water

add some hydrochloric acid this is going

to be 15 ml of hydrochloric acid - 250

ml of water and then we're going to add

a tiny amount of palladium chloride

point-o 6 to 5 grams in this case and it

dissolves very slowly so you want to

take your time and heat it up a little

bit 40 or 50 degrees C to help the stuff

dissolve don't move on to the next step

until it's completely dissolved and then

after the palladium chloride is

dissolved you add 3 grams of stannous

chloride and it's you can see the bottle

here this solution goes through some

interesting color changes after adding

the stannous chloride it's sort of

greenish dark green and then if you wait

about an hour or two which is what you

have to do in order for the solution to

be ready it turns this interesting brown

color an alternative approach to this

palladium chloride colloidal solution is

to use the two ingredients separately so

you can have a stannous chloride

solution here and a palladium chloride

solution here and you can do it

sequentially so you dip your part first

in the stannous chloride rinse it and

then dip it into the palladium chloride

rinse it and then go into the bath and

the benefits of this idea is that since

it's not a colloid these solutions are

much more stable so that you can just

use them for a long long time you don't

have to worry about it falling out

however I haven't had much luck using

this process I pretty much always go

with the colloidal and we'll explain why

in the next few steps okay so the basic

process of completely plating an object

like this piece of circuit board

material is to wash it very carefully in

fact washing it is another critical step

that is sometimes overlooked you got to

use something pretty powerful like this

Alka Knox cleaner and you want to heat

it up to 40 or 50 degrees C and then dip

the part in there with agitation for a

good 20 minutes to make sure the part is

completely squeaky clean if there is

even a trace of oil and I mean when I

say a trace I mean there's like oil

droplets in the air normally and if you

just leave a part out on the counter it

will eventually accumulate a very very

thin layer of oil on it and so you got

to get rid of that so you take it out of

the Alka Knox rinse it quickly into the

activator rinse it into the plating bath

rinse it and then we're done

getting all that working took quite a

while but unfortunately with plastic

it's even more difficult as we'll see so

after getting this electroless copper

process working pretty reliably on

circuit board material I decided to

start trying it out on 3d printed parts

and so I'm using a formlabs

form 2 printer and I'm using the clear

resin and right away I realized I had a

big problem so this is part number one

the first of many samples and I used the

laser cutter to mark these stripes here

at different power levels with the laser

so this is about 12% and this is maybe

20% of my 60 watt laser cutter in sort

of a raster mode and as you can see we

got a big problem one the part plates

where I don't want copper and then where

the laser hit it the plating is actually

not as good so we have two problems one

we have to figure out a way to prevent

the copper from sticking where we don't

want it and then we also have to sort of

invert what's happening with the laser

here so you can kind of separate this

whole thing into two problems I spent

probably a month or two researching you

know off and on this whole process and

how there's existing technology to make

selective copper deposition like this

and it seems like surfactants and

controlling sort of surface

affinity is a pretty big deal so I

started experimenting with sodium lauryl

sulfate which came up in one of the

papers that I found and that researcher

was using this surfactant which is short

for surface active agent it basically

changes how hydrophilic the surface of a

material is right so if you've heard of

detergent herbs or soap even it's

basically a way of bridging this surface

that doesn't want to interact with water

the surfactant allows the water to start

interacting with the surface and what

this comes down to is basically dipping

the part into the catalyst means that

that catalyst has to come into really

intimate contact with the surface in

order to stick there and then if it

sticks there then when we put it in the

plating bath we get copper there so this

whole thing comes down to controlling

whether the catalyst sticks or not to

the part so as it turns out sodium

lauryl sulfate is an anionic surfactant

meaning that the molecule is negatively

charged and it's other part of the

molecule is hydrophilic so it will

attach to positively charged surfaces

because it's negatively charged and

allow that surface to be hydrophilic and

when I started experimenting with this I

actually found that it had the opposite

effect so when I was using SLS it would

cause the laser Daria's to be even worse

like you know taking the copper even

worse than without it and so this this

process took a very long time but I

eventually figured out that maybe I

should try a surfactant of the opposite

charge a cationic surfactant and here it

is the secret ingredient that makes all

of this possible is wet & Forget that's

right this is actually 10 percent

alcohol dimethyl benzyl ammonium

chloride and doesn't sound very common

as it turns out this surfactant kills

moss mold and mildew it's also great for

making circuit boards so my best guess

to what's happening here is that the

laser cutter when it touches an area of

the plastic will charge the surface and

then when we put it into the

go ahead and forget the charge is

appropriately set up such that that

surfactant will cause the area to become

super hydrophilic and then when we dip

it in the catalyst the Palladium

particles stick there then we put it in

the plating bath we get copper there and

so I figured out that by going through

this process I could make the laser

Daria's take copper really well but then

we had the remaining problem of getting

rid of the copper where we don't want it

to solve that problem I also tried many

different things and found that coating

the piece of plastic before lasering it

with this lubricant called tri flow

actually worked really well and really

what this is is just a an oil a very

light oil but I've tried a lot of

different kinds and found that tri flow

works by far the best and so the idea is

that we coat the part in tri flow now

it's not hydrophilic at all because you

know oil repels water of course right so

the oil kind of soaks into the top layer

of the part and if we were to go through

the whole process with that we would get

absolutely nothing in fact this is what

you'd get right so this went through the

whole process with the oil and it takes

no copper at all and that's because the

oil is really effective at keeping the

palladium away there's no palladium we

put it in the copper bath there's no

activation and there's no plating so now

we have kind of all the ingredients

coming together and when I was getting

up to about you know test number 66 or

whatever here it started to fall into

place and I realized that I could coat

the sample with oil then laser it then

put it in the surfactant then activate

it and then I played it with copper and

right around sample number 83 I really

dialed it in and realized that this was

going to work a lot of process variables

to control here so let's just step

through it and you can see at all okay

to start off we start with a 3d printed

part and I'm just making flat little

test coupons to make life easy and as an

optional step I dip it in sodium lauryl

sulfate a very dilute solution and I

don't think this is really necessary but

it's just kind of extra insurance

it makes sure

the surface is absolutely unresponsive

to any plating process next I blow-dry

it and then apply the Tri flow and you

really don't have to soak it I mean just

putting a few drops of Tri flow on there

and then wiping it off completely is

really all that's necessary next I put

it in the laser cutter and let it do its

thing using a raster pattern to make the

traces and then using a cut pattern to

make the little vias and the process

window on this is pretty big like I've

tried higher power and lower power and

it doesn't make a huge difference you

don't want to do a high power thing

though because it removes too much

material and then the copper areas are

just physically lower than the surface

and that makes soldering more difficult

so basically you want to use as little

laser power as possible then we dip it

into the secret secret ingredient the

wet & Forget and i diluted this down to

1% so a 10 to 1 dilution from the

commercial product gives a 1% surfactant

solution and I leave it in for 1 minute

next I rinse the part in distilled water

and then put it into the palladium

colloidal bath for about 2 and 1/2

minutes next rinse it in distilled water

again and then put it into the copper

plating bath at about 40 degrees C with

stirring for about an hour and a half

now the air bubbler here is

controversial remember how I was saying

that this bath works by having the

formaldehyde reduce the copper causing

the copper oxide to become copper metal

and if you put an air bubbler in there

you're introducing more oxygen into the

bath and that will actually slow down

what's happening that's good because it

makes the bath more stable you can kind

of control it a little better but I

actually found a pretty big downside at

first I thought oh I know it's a great

idea I'll use the air bubbler and it

will push away all the little hydrogen

bubbles that form on the

as part of this process right because

you know you get a hydrogen bubble

forming on your part then it's not gonna

plate there anymore and so it makes the

results inconsistent so at first I was

thinking the air bubbler is great one

because it stabilizes the bath and two

it you know sweeps away all this

hydrogen but as it turns out it actually

completely destroys some parts there's

if you put it right in the Airstream

eventually a bubble an air bubble will

touch the copper and very slightly

oxidize it and then it's not active

anymore and it actually halts the entire

process from working so I eventually

gave up on the air bubbler and found

that this bath for which I gave the

recipe in this video is stable enough

where it doesn't really need the oxygen

bubbler after the plating is done it's

pretty much it just cleaning it up with

a little bit of naphtha and just rubbing

it pretty firmly with a paper towel will

take off any traces of copper that

they're sort of sticking to that oil

layer that you don't really want and I

have to admit later on I found out that

sandblasting the 3d printed part helps a

lot and I'm trying to figure out how to

make the process work without a

sandblaster because that's an additional

piece of equipment that you might need

the goal in doing this whole thing was

to make a process that anyone with a 3d

printer and a laser cutter could do in

in a hackerspace

the process still works without

sandblasting of course it just makes the

results more consistent especially for

fine pitch work if you're doing larger

traces like 20 or 30 mil wide traces

none of this matters at all it's it's

totally fine if you're going that big so

that's basically where we are the

remaining problems are the adhesion if

the copper to the plastic is really good

actually

until the flux hits it and I know it's

the flux because I've plated some things

continuously in copper and you can

solder to here in the adhesion is pretty

good I add a wire on here there's the

surface mount component and you can push

on it pretty hard and it's it's not

coming off I eventually yanked the wire

off but it took a lot of force to to rip

this open the trouble is if you're doing

you know a relatively thin trace like

this and soldering it with paste or

whatever the flux gets under the copper

and then that destroys the adhesion

it's really terrible and that demo piece

that I showed off at the beginning of

the video is not strong like I admit

it's it's a very fragile piece and so

figuring out how to get the copper to

stick to the plastic and withstand the

flux is really the trick it's not the

temperature because I put my iron right

on here and it's still holding just fine

even the trick is that since the copper

was continuous it kept the flux out so

you can see here what the air bubbler

did notice in the upper one this second

p in the word applied looks all corroded

it actually came out of the bath looking

just like that and this one I had the

air bubbler going and realized what was

happening and funny enough it kind of

spreads you know that that second P is

completely corroded but the letters next

to it are totally fine it's weird how

the corrosion kind of spreads to all the

areas that the copper is touching but

not further and then the second one I

realized what was happening and quit

with the air bubbler and ended up with

better results there let's finish up by

talking about how these are actually

used commercially already so all these

test coupons are flat and rectangular of

course but the real excitement with

making a plastic part with a printed

circuit on it is that it doesn't have to

be flat it can have all kinds of weird

geometry and if you combine this with

through holes and everything else you

can do all kinds of cool stuff and the

chances are you're looking at one of

these parts right now or it's in your

pocket this is actually a piece of a

cell phone and these are the conductive

traces that have been applied to this

3-dimensional plastic part this is

actually the antenna for this cell phone

that this came out of and so that the

conductive trace reps around the outside

and makes contact with the phone circuit

port here and then provides the antenna

designer this 3d surface to design an

antenna on which is pretty nice I picked

this one up at a trade show just and

they were showing off their high

resolution capability I'd say this is

about maybe 8 mil maybe even 6 mil trade

space probably more like 8 though and

they've gold coated it so that it

doesn't corrode of course but I think

it's just copper under there the way

these are made is pretty interesting

these guys are also laser defined but

they use a very expensive pulse

laser they don't use a co2 laser like

you'd find in your average hackerspace

and part of my goal in doing this whole

project was to avoid needing this very

expensive pulsed laser so the way this

one works is they add a special powder

to the plastic when this is injection

molded and the powder is basically a

catalyst it's not palladium but it's a

similar catalyst so if the injection

molded this whole part you would end up

with something non conductive because

the catalyst by itself is not conductive

but then they put this in a machine that

hits it with a laser selectively

and where the laser hits this catalyst

it becomes active then they dip the

whole thing into an electrode list

copper bath just like I showed in the

video and those areas that are now

activated become coated with copper when

I started this entire journey months ago

my original goal was to mix the powdered

catalyst with the 3d printed resin and

then take it out of there and then hit

it with the laser and try to go through

the whole process and then once I

realized that we could do this on the

surface without bothering with you know

powdered catalysts and whatever it's you

know it's way easier it's way better it

could work with potentially any resin

that comes out of that 3d printer also

one other note probably a lot of you are

asking does it work on PLA no and the

unfortunately it doesn't and the reason

is that the plating bath is very high pH

and PLA disintegrates in high pH

solutions so unfortunately the chemistry

of depositing copper like that makes it

such that it just simply won't work with

PLA of course I tried it just to be sure

and not only does the part get ruined it

actually ruins the entire plating bath

what happens is the the PLA starts to

disintegrate and then all of the

catalysts and little bits of copper that

have started to deposit

you know move out into the solution and

the whole thing crashes in a matter of

thirty minutes basically all the copper

drops out and you have to start over

again anyway I did go a little bit down

the path of trying out these embedded

catalysts and so to test this out and

stuff some epoxy with copper oxide which

is one of these latent catalysts that

you can put into a resin and

interestingly enough if you put copper

oxide and epoxy together and then put

that in the laser cutter and D focus the

laser beam it will actually make copper

traces all by itself you don't have to

plate anything there's no path or

anything like that

and at first I might think we'll wait a

minute but how does amine heating up

copper oxide doesn't turn it into copper

the trick is that the hot laser beam is

vaporizing the epoxy resin and it's

creating a really strong reducing

environment because it's very hot in

there and the epoxy is trying to burn

but it's not able to get enough oxygen

going and so the the hot burning epoxy

actually reduces the copper oxide down

the copper metal and it makes a

conductive trace I mean it's not very

good and as soon as you flex it it's

gonna pull apart so it's it's not really

usable but it's kind of an interesting

trick okay well you know put your

questions in the comment section I'll do

my best to answer them I'm gonna

continue working on this and if anyone

else is really interested in it let me

know and I'll give you as many details

as I can okay see you next time byeTop Search Keyword : online earning, , make money online, earn money online, online earning, online earning sites, make money online free, online money income, earn money online free, money online, best way to earn money online, online income site, money earning websites, best online earning sites, easiest way to earn money online, earn money payment bkash, online money income site