Most semiconductor devices are enclosed in ceramic, metal or plastic packages to prevent damage to the chip and its fragile connecting wires. Despite this important function, packaging was one of the most neglected aspects of semiconductor design. Programs were delayed because the chip was too large or consumed too much power for the designated package. Typical 1960s transistors used TO-5 or TO-18 (Transistor Outline) metal-can packages with three external leads. Lower-cost plastic versions served applications not requiring a hermetic seal. Fairchild mounted its first Micrologic ICs in such transistor cans modified to accommodate up to 10-leads. Yung Tao at Texas Instruments developed a 10-lead, 0.25 by 0.125 inch flat-pack to occupy the smallest possible board area in avionics systems.
Most of these package iterations were derived from existing formats that were not conceived for high-density board designs. In 1965 Don Forbes, Rex Rice, and Bryant ("Buck") Rogers at Fairchild devised a 14-lead ceramic Dual-in-Line Package (DIP) with two rows of pins 100 mils apart that revolutionized computer manufacturing by simplifying layout and allowing automated insertion into printed circuit boards. Low-cost, plastic-molded versions of the DIP outline dominated production volumes by the early 1970s and pin-counts increased up to 64 leads.
While most DIP designs used thermo-compression or ultrasonic bonding to attach fine gold or aluminum wires to the chip, some vendors experimented with tiny solder bump interconnects and variations on a beam-lead approach invented by Martin Lepselter of Bell Labs for high-reliability applications.
Texas Instruments Collection. The National Museum of American History, Chip Collection (Smithsonian Institution) holds numerous documents relating to packaging of T.I. semiconductors. [NMAH cross reference 1987.0487]
Lepselter, M. P. "Beam-lead Technology," Bell System Technical Journal Vol. 45 (February 1966) pp: 233-253.
Rogers, Bryant. "IC packages: Which one to Use," Solid State Technology, (September 1968) pp 45-46
Smits, F. M. ed. A History of Engineering and Science in the Bell System: Electronics Technology (1925-1975) (AT&T Bell Laboratories, 1985) pp. 110-113.
Tummala, Rao R., Rymaszewski Eugene J., Klopfenstein, Alan G. (Editors) Microelectronics Packaging Handbook Parts I. II, and III. (Springer, 1997)
Lécuyer, Christophe. Making Silicon Valley: Innovation and the Growth of High Tech 1930-1970. (Cambridge: The MIT Press, 2006) p. 246.