Integrated circuits (ICs) are a keystone of modern electronics. They are the heart and brains of most circuits. They are the ubiquitous little black “chips” you find on just about every circuit board. Unless you’re some kind of crazy, analog electronics wizard, you’re likely to have at least one IC in every electronics project you build, so it’s important to understand them, inside and out.
An IC is a collection of electronic components – resistors, transistors, capacitors, etc. – all stuffed into a tiny chip, and connected together to achieve a common goal. They come in all sorts of flavors: single-circuit logic gates, op-amps, 555 timers, voltage regulators, motor controllers, microcontrollers, microprocessors, FPGAs…the list just goes on-and-on.
The package is what encapsulates the integrated circuit die and splays it out into a device we can more easily connect to. Each router connection on the die is connected via a tiny piece of gold wire to a pad or pin on the package. Pins are the silver, extruding terminals on an IC, which go on to connect to other parts of a circuit. These are of utmost importance to us because they’re what will go on to connect to the rest of the components and wires in a circuit.
There are many different types of packages, each of which has unique dimensions, mounting-types, and/or pin-counts.
One of the main distinguishing package type characteristics is the way they mount to a circuit board. All packages fall into one of two mounting types: through-hole (PTH) or surface-mount (SMD or SMT). Through-hole packages are generally bigger, and much easier to work with. They’re designed to be stuck through one side of a board and soldered to the other side.
Surface-mount packages range in size from small to minuscule. They are all designed to sit on one side of a circuit board and be soldered to the surface. The pins of an SMD package either extrude out the side, perpendicular to the chip or are sometimes arranged in a matrix on the bottom of the chip. ICs in this form factor is not very “hand-assembly-friendly.” They usually require to aid in the process.
DIP (Dual in-line packages):
DIP, short for a dual in-line package, is the most common through-hole IC package you’ll encounter. These little chips have two parallel rows of pins extending perpendicularly out of a rectangular, black, plastic housing.