melting solder in a pot

[Ian.M]

Take some solder (wire), bend it into a complex shape, put it onto a heat resistant surface and heat it to melting point with a hot air gun.  You will find that it wont stay where you put it as surface tension will pull it together into blobs leaving gaps between them.  The same will apply if you were trying to cast tracks from liquid solder.   The casting needs pressure, normally provided by the weight of liquid metal in the sprue, to force the liquid metal into the fine detail of the mold, and to get it to fill fine channels, you'd need the mold to be preheated above the solder melting point so it doesn't chill and block off the channels.  Each channel would need a vent hole at the far end and a runner and riser feeding it from the sprue.

You *COULD* get there by lost-wax casting using a 3D printed pattern: https://hackaday.com/2020/12/07/how-to-get-into-lost-wax-casting-with-a-dash-of-3d-printing/

[Capernicus]

Thats a nice smooth surface on that one.    So im seeing a tree connecting all the pieces together that the solder runs through,   A circuit is a tree at times,  maybe if I make it in a tree shape fanning out downward,  that would work?    Would make for a strange looking PCB,  but I dont mind that if it would cast successfully.

Ive been doing 3d printing without supports lately, im getting good at it too.    So this would be another form of constrained modelling to suit the fab process, perhaps.

[ebastler]

How much harder than making little lead army men can it be?  That's what I was watching when the idea popped in my head.

Aha! Now it makes perfect sense. Tin soldiers are to PCBs what FPGAs are to GPUs: They have very little to do with each other. 

Seriously though -- PCB manufacturing is a solved problem. I am in the dark what you are trying to achieve here. Have you considered making your "PCBs" from cookie dough and silver paint, or from cardboard and aluminium foil?

Even if FPGA's were $20, ur still better off making em yourself if u want large numbers of things.

I assume (I hope!) you are talking about making your own PCBs, not making your own FPGAs?

If so, you are quite wrong. Have you looked at the volume pricing at JLCPCB and other vendors? 100 PCBs will cost you hardly more than 10. In contrast, your homebrew process is bound to scale far less effectively. So the more units you need, the more reason you have to go to an outside vendor who has a properly streamlined, automated manufactring process.

[ElizatronicWarfare]

This is clearly fake and intended to waste everyone's time. Having bad ideas is one thing, doubling down to the point of parody when advised against them is another. Don't feed the troll.

[Zero999]

Just think of the plusses!

You dont solder to put your components on, you just need to warm it up and stick em in!  =)

Just think of the minuses!

Solder has very poor conductivity compared to copper.

you could electroplate it in copper sulphate, then the resistance would go away a lot.

That will only produce a very thin layer of copper, which will hardly reduce the resistance.

People aren't trying to put you off learning electronics here. We're advising you against something which is dangerous and will not work.

If you want to make your own PCBs. Buy some copper clad board and an etchant such as feric chloride. If you have a laser printer, or can use a photocopier at the local library, toner transfer can be used to get the artwork onto the board, before etching. There are special proprietory papers but ordinary copier paper works quite well, although I've found clay coat magazine paper is the best. Another much better method is the photographic process, but it requires more equipment and chemicals: UVA lamp (UV LEDs, blacklight, or insect killer tubes, never use germincidal UVC lamps), photoresist, or use presensitised board and a developer such as hydrogen peroxide. You don't need a specal tank for etching, just use a small plastic tray and heat the solution in the microwave.

There are lots of tutorials on how to make your own PCBs.

[Ian.M]

You could of course make your own PCBs from scratch.  Most people would start with copper-clad FR4, but the next step back would be copper foil, etched and lightly oxidized so that Epoxy resin will bond to it, an appropriate laminating resin and glass-cloth, with a vacuum press to hold them together till the epoxy reaches a 'green' cure.      However I feel that's too simple for you, so why not  refine your own copper from ore and roll it down to foil thickness, make your own epoxy resin from precursor chemicals and weave your own glass-cloth from hand pulled glass fibers?   

On the more serious side:  I have seen some reports of success using a thin layer of acrylic spray paint as an etch resist and ablating it where you don't want copper using a consumer grade CO² laser cutter. e.g. https://hackaday.com/2017/08/22/laser-etching-pcbs/  Unfortunately the spot size is too large to allow fine pitch PCBs or even tracks between 0.1" pitch pads.

[tooki]

For the benefit of the other readers not the OP: The closest thing this crackpot idea reminds me of is a long-abandoned electronics construction technique called ECME. Take a look:

[calzap]

How about using Wood’s metal?  All you need is a pot of boiling water to melt it.  Has the toxic advantage of adding cadmium to the lead. 

Mike in California

[ebastler]

For the benefit of the other readers not the OP: The closest thing this crackpot idea reminds me of is a long-abandoned electronics construction technique called ECME. Take a look:

Thank you! That is a great find. Quite an impressive level of automation, integrating the manufacturing of passive components, circuit boards, and partial assembly (well at, least the sockets) in a single automated workflow.

A nice article here in the New Scientist: https://www.newscientist.com/article/mg17623656-200-the-chunkiest-chip/. This one is behind a paywall, but you can find free copies of the text on some Vietnamese (?) sites with English language course materials. (Where else? )

[Capernicus]

For the benefit of the other readers not the OP: The closest thing this crackpot idea reminds me of is a long-abandoned electronics construction technique called ECME. Take a look:

That looked good, I was quite impressed.  The circuit is nice and solid looking if its based apon an embossment,  maybe not quite as detailed, and they did get something like 50,000 radios out of it or maybe more?  (Way too many,  they probably started giving them away for free. )
Compared to the hand soldered to the chassis sausage systems it was against, it looks like a much superior product.  (And much less manpower required.)

Imagine if they moulded the chassis and the inner circuit at the same time,  and u sorta get the wholer radio in one hit! =)

Use clay slip, and clay slip mixed with graphine for the conductor.