PCB specs?

[believer]

I am looking at MB specs and see a catagory named "PCB size". Whis is the PCB?

 

[mmenarry]

Printed Circuit Board
The big piece of metal covered plastic evreything is attached to. Basically, the most common size these days is ATX, sort of upright midi-tower size. Micro-ATX is smaller, for mini tower cases. Micro ATX is sometimes written as uATX, being all fancy and using "miu", the greek symbol for "micro"
Michael

 

[stevieblunder]

Actually, PCBs are made of about 10 layers of fiberglass/epoxy and, of course, copper foil. The copper foil is etched (printed) into very fine lines (traces) that connect the chip pins where ever they need to go. Tiny holes called vias connect between traces on different layers. Some layers are large planes of copper, ie ground, 5-volt, 3-volt, and maybe 12-Volt power is distibuted on these power planes.

Virtually all PCBs today are surface mount. In the old days, all parts were called "through hole", because the parts had wires that were soldered into the PCB, not just on the surface pads. Back them, people placed parts by hand. Now, parts are taken off a spool by a pick and place machine, into solder paste that is applied with a stencil, and the whole board is heated to melt the solder. Most resistors and capacitors today are too small to handle by hand.