Computer Chips

[herme3]

I've always read that there are many transistors inside a computer chip. However, when I took the CPU out of an old computer, I cut through the plastic outside shell of the CPU, and it appeared to by empty inside. From the outside, it looked like about 20 metal connectors that enter the CPU. Inside, I saw that they simply go through the CPU, and out the other side. I didn't see any other pieces inside the CPU. I kept cutting the CPU into smaller pieces, but I could find nothing inside. How did the CPU work? I think the name of the CPU was a Z80. The processor was only about 2 Mhz. Wouldn't there still have to be other pieces inside to make it work?

[Dave]

The transistors are extremely small, and put in layers in the CPU. You might need something like a magnifying glass to see them. Or you could be cutting the wrong bits, I don't know.

[herme3]

I kept cutting the CPU until all that was left was little pieces. All I could find inside was a black plastic-like material and the metal connectors that went into both sides of the CPU. I also saw a small metal square in the center of the chip. It was as thin as paper, and about 1/4 the size of a penny. It looked like a piece of aluminum foil. Could this have had the transistors on it? I looked carefully, and I didn't see anything on it, but I never looked at it with a magnifying glass.

[5614]

indeed, i have lying on the floor behind me a pentium 1 computer, being P1 it should only have a few thousand transistors, new P4 has 42 million.

 

at the same time i cant see any! they are microscopic, inbuilt into chips, and probably those tiny things you just mentioned as well...

[Lance]

The transistors are etched onto pieces of silicon.

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=413&item=6147112337&rd=1

[Silencer]

Basically, the criss-crossing metal is what makes it work. For current to pass through one circuit (think one street in an intersection) electricity also has to be flowing through the other (the other street, except the cars don't crash). Hence the 1/0 on/off action.

 

http://www.howstuffworks.com has some nice articles on the subject.

[bh_doc]

I also saw a small metal square in the center of the chip. It was as thin as paper, and about 1/4 the size of a penny. It looked like a piece of aluminum foil. Could this have had the transistors on it?

 

Yep, that was it. And it's likely made from a mixture of mostly silicon and some other stuff ("doping agents", I think) that direct the flow of electrons. IIRC, that little metal square is called the "die". Dies are very small, and have chemically etched into them the microscopic transistors you're trying to find. You have NO hope of seeing them with the naked eye - you'd need a pretty decent microscope to see the changes in the metal, if you can see them at all.

 

I looked carefully, and I didn't see anything on it, but I never looked at it with a magnifying glass.

 

A magnifying glass is probably not powerful enough. These integrated circuits are tiny!

[Silencer]

Common doping elements are arsenic, phosphorus, boron, and gallium, depending on whether it is a positive or negative diode.

[herme3]

How do companies make computer chips? Some chips contain millions of transistors. How can they all fit in such a little chip and still work together with so much precision? How can they be created when humans can't even see them?

[atinymonkey]

Lasers. Magical Lasers.

[YT2095]

as well as High power microscopes, etching techniques (photo etching), very pure Acids, the templates for the substrate and layers are mostly all computer designed now also.