Solid Logic Technology (SLT) was IBM's method for hybrid packaging of electronic circuitry introduced in 1964 with the IBM System/360 series of computers. It was also used in the 1130, announced in 1965. IBM chose to design custom hybrid circuits using discrete, flip chip-mounted, glass-encapsulated transistors and diodes, with silk-screened resistors on a ceramic substrate, forming an SLT module. The circuits were either encapsulated in plastic or covered with a metal lid. Several of these SLT modules (20 in the image on the right) were then mounted on a small multi-layer printed circuit board to make an SLT card. Each SLT card had a socket on one edge that plugged into pins on the computer's backplane (the exact reverse of how most other companies' modules were mounted).
IBM considered monolithic integrated circuit technology too immature at the time. [1] SLT was a revolutionary technology for 1964, with much higher circuit densities and improved reliability over earlier packaging techniques such as the Standard Modular System. It helped propel the IBM System/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, although some later SMS cards held SLT modules. SLT had several updates during its life, the last being the Monolithic System Technology (MST) which replaced the single transistors of SLT with small-scale integrated circuits that held four or five transistors. MST was used in the System/370, which began to replace the System/360 in 1970.
SLT used silicon planar glass-encapsulated transistors and diodes. [2]
SLT uses dual diode chips and individual transistor chips each approximately 0.025 inches (0.64 mm) square. [3] : 15 The chips are mounted on a 0.5 inches (13 mm) square substrate with silk-screened resistors and printed connections. The whole is encapsulated to form a 0.5 inches (13 mm) square module. Up to 36 modules are mounted on each card, though a few card types had just discrete components and no modules. Cards plug into boards which are connected to form gates which form frames. [3] : 15
SLT voltage levels, logic low to logic high, varied by circuit speed: [3] : 16
The same basic packaging technology (both device and module) was also used for the devices that replaced SLT as IBM gradually transitioned to the use of monolithic integrated circuits:
An integrated circuit (IC), also known as a microchip, computer chip, or simply chip, is a small electronic device made up of multiple interconnected electronic components such as transistors, resistors, and capacitors. These components are etched onto a small piece of semiconductor material, usually silicon. Integrated circuits are used in a wide range of electronic devices, including computers, smartphones, and televisions, to perform various functions such as processing and storing information. They have greatly impacted the field of electronics by enabling device miniaturization and enhanced functionality.
A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits. Because transistors are the key active components in practically all modern electronics, many people consider them one of the 20th century's greatest inventions.
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function and the amplifying function, as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logic (DTL).
In electronics, emitter-coupled logic (ECL) is a high-speed integrated circuit bipolar transistor logic family. ECL uses an overdriven bipolar junction transistor (BJT) differential amplifier with single-ended input and limited emitter current to avoid the saturated region of operation and its slow turn-off behavior. As the current is steered between two legs of an emitter-coupled pair, ECL is sometimes called current-steering logic (CSL), current-mode logic (CML) or current-switch emitter-follower (CSEF) logic.
The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as transistors and then integrated circuit (IC) chips. Around 1953 to 1959, discrete transistors started being considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology subsequently led to the development of semiconductor memory in the mid-to-late 1960s and then the microprocessor in the early 1970s. This led to primary computer memory moving away from magnetic-core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size, and power consumption of computers. These advances led to the miniaturized personal computer (PC) in the 1970s, starting with home computers and desktop computers, followed by laptops and then mobile computers over the next several decades.
Resistor–transistor logic (RTL), sometimes also known as transistor–resistor logic (TRL), is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit; it was succeeded by diode–transistor logic (DTL) and transistor–transistor logic (TTL).
Diode–transistor logic (DTL) is a class of digital circuits that is the direct ancestor of transistor–transistor logic. It is called so because the logic gating functions AND and OR are performed by diode logic, while logical inversion (NOT) and amplification is performed by a transistor.
In computer engineering, a logic family is one of two related concepts:
The Standard Modular System (SMS) is 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. SMS was superseded by Solid Logic Technology (SLT) introduced with System/360 in 1964, however they remained in use with legacy systems through the 1970s.
A hybrid integrated circuit (HIC), hybrid microcircuit, hybrid circuit 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 (PCB). A PCB having components on a Printed Wiring Board (PWB) is not considered a true hybrid circuit according to the definition of MIL-PRF-38534.
A multi-chip module (MCM) is generically an electronic assembly where multiple integrated circuits, semiconductor dies and/or other discrete components are integrated, usually onto a unifying substrate, so that in use it can be treated as if it were a larger IC. Other terms for MCM packaging include "heterogeneous integration" or "hybrid integrated circuit". The advantage of using MCM packaging is it allows a manufacturer to use multiple components for modularity and/or to improve yields over a conventional monolithic IC approach.
The Launch Vehicle Digital Computer (LVDC) was a computer that provided the autopilot for the Saturn V rocket from launch, through Earth orbit insertion, and the trans-lunar injection burn that would send the Apollo spacecraft to the Moon. Designed and manufactured by IBM's Electronics Systems Center in Owego, New York, it was one of the major components of the Instrument Unit, fitted to the S-IVB stage of the Saturn V and Saturn IB rockets. The LVDC also supported pre- and post-launch checkout of the Saturn hardware. It was used in conjunction with the Launch Vehicle Data Adaptor (LVDA) which performed signal conditioning from the sensor inputs to the computer from the launch vehicle.
A Flip-Chip module is a component of digital logic systems made by the Digital Equipment Corporation (DEC) for its PDP-7, PDP-8, PDP-9, and PDP-10 computers, and related peripherals, beginning on August 24, 1964.
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical circuit. For a circuit to be referred to as electronic, rather than electrical, generally at least one active component must be present. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another.
A transistor computer, now often called a second-generation computer, is a computer which uses discrete transistors instead of vacuum tubes. The first generation of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky and unreliable. A second-generation computer, through the late 1950s and 1960s featured circuit boards filled with individual transistors and magnetic-core memory. These machines remained the mainstream design into the late 1960s, when integrated circuits started appearing and led to the third-generation computer.
Integrated passive devices (IPDs), also known as integrated passive components (IPCs) or embedded passive components (EPC), are electronic components where resistors (R), capacitors (C), inductors (L)/coils/chokes, microstriplines, impedance matching elements, baluns or any combinations of them are integrated in the same package or on the same substrate. Sometimes integrated passives can also be called as embedded passives, and still the difference between integrated and embedded passives is technically unclear. In both cases passives are realized in between dielectric layers or on the same substrate.
A semiconductor package is a metal, plastic, glass, or ceramic casing containing one or more discrete semiconductor devices or integrated circuits. Individual components are fabricated on semiconductor wafers before being diced into die, tested, and packaged. The package provides a means for connecting it to the external environment, such as printed circuit board, via leads such as lands, balls, or pins; and protection against threats such as mechanical impact, chemical contamination, and light exposure. Additionally, it helps dissipate heat produced by the device, with or without the aid of a heat spreader. There are thousands of package types in use. Some are defined by international, national, or industry standards, while others are particular to an individual manufacturer.
The first planar monolithic integrated circuit (IC) chip was demonstrated in 1960. The idea of integrating electronic circuits into a single device was born when the German physicist and engineer Werner Jacobi developed and patented the first known integrated transistor amplifier in 1949 and the British radio engineer Geoffrey Dummer proposed to integrate a variety of standard electronic components in a monolithic semiconductor crystal in 1952. A year later, Harwick Johnson filed a patent for a prototype IC. Between 1953 and 1957, Sidney Darlington and Yasuo Tarui proposed similar chip designs where several transistors could share a common active area, but there was no electrical isolation to separate them from each other.