DIP

What it is

A DIP (Dual In-line Package, sometimes DIL — Dual In-Line) is a through-hole IC package with two parallel rows of pins, traditionally on a 2.54 mm (0.1 inch) pitch. It's the classic rectangular black chip everyone recognises from 1970s and 1980s electronics — the one you push into a socket or into a breadboard.

The format became widely popular in the mid-1960s, with Fairchild among the companies instrumental in its adoption, and it stayed the default IC package for most of two decades. Everything from a 555 timer to an early microprocessor came in DIP.

How it's laid out

A DIP body is a moulded plastic (or occasionally ceramic) rectangle with a row of pins along each long edge. Two body widths dominate in practice:

• 0.3 inch narrow — the most common narrow DIP body width, used across a wide range of pin counts. This is what straddles the centre groove of a standard breadboard cleanly.
• 0.6 inch wide — used for larger packages such as many 28-, 40- and 48-pin DIPs. A 0.6 inch DIP still straddles the centre gap of a typical breadboard, but takes up considerably more board space.

Pin 1 is marked with either a notch cut into one short edge, a small dimple next to pin 1, or both. Viewed from above with the notch pointing up, pin 1 is top-left and the numbering runs anticlockwise around the package.

Common variants

• PDIP (Plastic DIP) — the default cheap plastic package.
• CDIP / CERDIP — ceramic DIP variants (CERDIP is a particular ceramic-DIP construction; CDIP is the broader designation). They can offer higher-temperature operation, and in hermetically sealed versions much better environmental protection. Commonly used for military, aerospace and other high-reliability applications.
• SDIP (Shrink DIP) — same in-line layout on a 1.778 mm (0.07 inch) pitch: denser, but no longer directly breadboard-compatible.

Why almost no new chips are released in DIP

DIP is bulky and relatively expensive to manufacture and assemble: every lead requires a plated through-hole, and the package consumes much more board area than a comparable surface-mount part. The industry moved to surface-mount packaging in the 1990s and 2000s for exactly these reasons: cheaper, denser, faster to assemble by pick-and-place.

For modern high-volume digital ICs, DIP is rarely on offer. Where a through-hole version does exist (ATmega328P, 555, ATtiny85, some op-amps and logic gates, a fair chunk of analogue / interface / power / isolation parts), it's usually aimed at prototyping, education, legacy compatibility, or applications where hand assembly matters.

Why the format still matters

The 2.54 mm pin spacing and the standard narrow-DIP body width are particularly well-matched to conventional solderless breadboards — the central gap and tie-point layout on most breadboards is designed around common DIP packages. That's the format our breakouts imitate: an SMD chip on top, a two-row through-hole pin header on the underside on DIP-compatible spacing. It slots into a breadboard the same way a DIP would, even though the assembly on top is not itself a DIP package.