Dimensions of the DIP-16 package in inches.

Even though it wasn’t implied by the advertising, ease of PCB layout was probably a design objective as well. The number of components on boards would inevitably increase as circuit complexity increased; providing power to all those chips and managing their signal routing on the board would soon become a challenge. The DIP design’s pin spacing of 0.1′′ (2.54 mm) and the distance between rows of pins of 0.3′′ (7.62 mm) allowed for enough of area for PCB traces to be routed between pins.

Another selling feature emphasised in the marketing materials was field serviceability. That trait undoubtedly resulted from what was likely the primary design objective: quick, inexpensive manufacturing processes. The IC die is affixed to a metal component known as the lead frame inside the DIP package. A progressive stamping press can simply manufacture the lead frame by punching the component from a continuous coil of sheet metal stock using a number of dies. In a single continuous process, the lead frames can be stamped, the dies attached, the die pads connected to the leads via ultrafine wires, and the DIP assembly encased.

Devices in the dual in-line packaging first appeared on the market in 1965, adhering to these design objectives. In an effort to offer the same hermetic seal demanded by the military for their equipment, Fairchild initially focused on ceramic encapsulation. Later, for less strict environmental regimes, encapsulation in plastic resin was introduced, which significantly reduced the unit cost.

The DIP was a tremendously successful package for the majority of 50 years because of its excellent design, low cost, and support for more sophisticated dies. However, technology soon outpaced the venerable design, and by the late 2000s, certain new chips were no longer offered packaged in DIPs. Its fundamental architecture was expanded to accept more leads and larger dies. Surface mount components may currently govern the PCB industry, but that wouldn’t be the case if Forbes, Rice, and Rogers’ design hadn’t paved the way.