Solid Logic Technology
Encyclopedia
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's method for packaging electronic circuitry introduced in 1964 with the IBM System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
series and related machines. IBM chose to design custom hybrid circuit
Hybrid circuit
A hybrid integrated circuit, HIC, hybrid microcircuit, or simply hybrid is a miniaturized electronic circuit constructed of individual devices, such as semiconductor devices and passive components , bonded to a substrate or printed circuit board...
s using discrete, flip chip
Flip chip
Flip chip, also known as Controlled Collapse Chip Connection or its acronym, C4, is a method for interconnecting semiconductor devices, such as IC chips and Microelectromechanical systems , to external circuitry with solder bumps that have been deposited onto the chip pads...
-mounted, glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
-encapsulated transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s and diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
s, with silk screened
Screen-printing
Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil. The attached stencil forms open areas of mesh that transfer ink or other printable materials which can be pressed through the mesh as a sharp-edged image onto a substrate...
resistor
Resistor
A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
s on a ceramic
Ceramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...
substrate. The circuits were either encapsulated in plastic or covered with a metal lid. Several of these were then mounted on a small multi-layer printed circuit
Printed circuit
Printed circuit may refer to:* Printed circuit board* Printed Circuit Corporation, an electronics manufacturer...
board to make an SLT module. Each SLT module had a socket on one edge that plugged into pins on the computer's backplane (the exact reverse of how most other company's modules were mounted). SLT was a revolutionary technology for 1964 with the reliability improvements over other assembly techniques helping propel the IBM/360 mainframe family to overwhelming success during the 1960s. SLT research produced ball chip assembly, wafer bumping, trimmed thick film resistors, printed discrete functions, chip capacitors and one of the first volume uses of hybrid thick film technology.
SLT replaced the earlier Standard Modular System
Standard Modular System
The Standard Modular System was a system of standard transistorized circuit boards and mounting racks developed by IBM in the late 1950s, originally for the IBM 7030 Stretch. They were used throughout IBM's second generation computers, peripherals, the 7000 series, the 1400 series, and the 1620...
.
Later developments
- Solid Logic Dense (SLD) increased packaging density and circuit performance by mounting the discrete transistors and diodes on top of the substrate and the resistors on the bottom.
- Advanced Solid Logic Technology (ASLT) increased packaging density and circuit performance by stacking two substrates in the same package.
- Monolithic System Technology (MST) increased packaging density and circuit performance by replacing discrete transistors and diodes with one to four monolithic integrated circuits (resistors now external from the package on the module).
Trivia
SLT was "rumoured" to be a core technology of the (then forthcoming) Xbox 360 games console after a spoof submission to the popular SlashdotSlashdot
Slashdot is a technology-related news website owned by Geeknet, Inc. The site, which bills itself as "News for Nerds. Stuff that Matters", features user-submitted and ‑evaluated current affairs news stories about science- and technology-related topics. Each story has a comments section...
tech site claimed as such.