Dual in-line package

Dual in-line package. A dual in-line package is a through-hole mounting style of electronic component packaging, characterized by two parallel rows of electrical connecting pins. It was the predominant form for integrated circuits for decades following its invention in the mid-1960s, offering a robust and easily handled format for printed circuit board assembly. The standardized footprint and pin spacing made it ubiquitous in consumer electronics, industrial controls, and early computing.

Overview

The DIP format was pioneered by engineer Bryant Rogers while working at Fairchild Semiconductor in 1964, emerging as a solution to the cumbersome packaging of early microchip designs. Its adoption was accelerated by the success of devices like the 7400-series of transistor–transistor logic chips and seminal microprocessors such as the Intel 8080 and the Zilog Z80. The package's design allowed for reliable wave soldering and facilitated prototyping on breadboards, which cemented its role in the Digital Revolution. For many years, the format was governed by standards from organizations like JEDEC and the International Electrotechnical Commission.

Construction and design

A standard DIP consists of a rectangular housing, typically molded from an epoxy plastic compound, though high-reliability versions use a ceramic or cerdip (ceramic-glass) body. The internal semiconductor die is attached to a lead frame, with fine bonding wire connecting the die's pads to the frame's leads. These leads extend from the sides of the package, forming two rows that are inserted into holes on a PCB. The pin spacing, or pitch, is standardized at 0.1 inch (2.54 mm) between rows and between pins within a row, a dimension critical for compatibility with sockets and prototyping boards. The number of pins typically ranges from 8 to 40, though configurations exist from 4 to 64.

Variants and derivatives

Several important variants evolved from the basic DIP design to address specific needs. The Skinny DIP (SDIP) and Shrink DIP (SHDIP) featured a reduced body width or pin pitch to increase component density. The Ceramic DIP (CERDIP) used a frit glass seal for hermeticity in military and aerospace applications, as specified in standards like MIL-STD-883. The Plastic Leaded Chip Carrier (PLCC), with J-leads, was a surface-mount descendant. For memory modules, the Single In-line Package (SIP) and Zigzag In-line Package (ZIP) were related concepts. Specialized types included the Dual In-line Memory Module (DIMM) for RAM and packages with integrated heat sinks for high-power devices.

Applications and usage

DIPs were foundational to entire generations of electronics. They housed the central processing units in early home computers like the Commodore 64 and the Apple II, as well as the read-only memory and programmable logic devices in arcade cabinets from companies like Atari and Namco. In telecommunications, they were used in Private Branch Exchange equipment from Northern Telecom and Siemens AG. The format remains in use for legacy system maintenance, in educational kits like those from Arduino, and for op-amps, voltage regulators, and other analog circuit components where through-hole reliability is valued.

Advantages and limitations

The primary advantages of the DIP included mechanical robustness, ease of manual insertion and replacement, and excellent suitability for prototype development and repair. The use of IC sockets allowed for easy upgrades and testing, a feature exploited in EPROM programmers. However, the package's limitations became acute with the push for miniaturization; its large footprint and through-hole requirement limited board density compared to surface-mount technology packages like the Small Outline Integrated Circuit (SOIC) or Quad Flat Package (QFP). The relatively long lead lengths also introduced unwanted parasitic inductance and capacitance, restricting high-speed performance in modern devices from firms like AMD or Intel Corporation.

Category:Electronic packaging Category:Integrated circuits Category:Computer hardware standards