Printing Circuits

While talking about building circuits, my very talented friend said to me:

“For me, soldering is a way to turn money into smoke.”

If you think about it, soldering is a very primitive activity. It is a cauldron of molten metal from the Middle Ages whose sole alchemy is making a single connection. A connection known for toxicity and burns. Toxicity, because until recently solder was full of toxic lead, and some are talking about returning to lead because of the whiskers that form with lead-free solder (ROHS compliance). Burns? Burns on both hands from soldering accidents over the years. None of which confer the ability to keep from getting burned again. Solder for regular people melts at 360 degrees F. The iron is over 500 degrees F. A soldering iron left unattended can burn down the house.

Most metals conduct with low resistance. You can, if you try hard enough, get other things to conduct, like certain plastics, but they are never as good.

We are children of the integrated circuit, invented by Jack Kilby at Texas Instruments in 1958. From then on printed circuits took off. Now you can get almost any circuit you can think of for FREE in something called a sample program. You ask the vendor and they send sample chips for free. Then you make something, and if it is a hit, they make back their money because you buy the reel of 15,000.

So we regular people could stand on the shoulders of giants but for one obstruction and that obstruction is soldering.

Soldering makes a metal-to-metal connection, nothing more than a bit of metal-to-metal logic. Now is the time to retire that connection to the Middle Ages.

That would have happened but for one little bug, one little fly in the ointment and that fly is capacitance.

Most of the time, capacitance is your friend. Want to smooth out the bumps in the road from power or switching? Install a capacitor. But when you want things to happen fast, capacitance puts on the brakes.

This bad kind of capacitance is aptly called parasitic. The solution is to use short or if possible, non-existent, wires.

One might say, "Why not cancel that capacitance with a little inductance? After all they ARE opposites aren’t they?" Well adding inductance to capacitance only throws gas on the fire when it comes to slowing things down because of one itty-bitty formula. Like its friend, E = mc², that formula is absolutely magical. It is (drum roll please):



Where L is inductance and C is capacitance. If you want to go fast, you have to make L and C small. The smaller you are, the faster you go until you aren’t there. Like Dylan said, "I'm glad I'm not who I am!" You’re traveling the speed of light, trading inductance for capacitance, in waves that shoot through space.

So what do I want already?

I want to be able to sit at my computer and design a circuit that uses a whiz-bang IC and then I want to click PRINT and have the circuit pattern ready to go. Then I want to GLUE the IC and other parts down to the metallic pattern printed on paper, fire it up and watch it blink or glow or do whatever it needs to.

And I don’t want the whole process of printing and gluing and firing it up to take more than 5 minutes, because that is really about as long as I can stand to wait.

And if I had that, I could make all kinds of things, like radios, and robots and glasses to see Dimension-N, just by printing and gluing and firing them up.

And I don’t want this just for me or my friend, I want it for everybody. I don’t want to build a million dollar lab and make a hundred thousand dollar machine.

I want a hundred dollar machine and two dollar glue.

Then I can live in a world that we can make a better and more interesting place.