Glossary S

SBU Sequential build-up
SCHEMATIC A diagram which shows, by means of graphic symbols, the electrical connections, components and functions of an electrical system.
SDRAM Synchronous Dynamic Random Access Memory: a new type of DRAM that can run at much higher clock speeds than conventional memory. SDRAM actually synchronizes itself with the CPU’s bus and is capable of running at 100 MHz, about three ties faster than conventional FPM RAM, and about twice as fast as EDO DRAM and BEDO DRAM. SDRAM is replacing EDO DRAM in many newer computers.
SELF-LIMITING SOLUTION A chemical solution that will not continue a reaction with the panel once a limit has been reached.
SEM Scanning electron microscope
SEMI Semiconductor Industry Association
SHORT Short circuit. An abnormal connection of relatively low resistance between two points of a circuit.
SIA Semiconductor Industry Association
SIGNAL A net other than a power or ground.
SILICON WAFER A thin, iridescent, silvery disk of silicon which contains a set of integrated circuits, prior to their being cut free and packaged.
SILKSCREEN The decals and reference designators in epoxy ink on a printed wiring board.
SIMM Single-In-Line Memory Module: a small circuit board that holds memory chips. A single in-line memory module (SIMM) has a 32-bit path to the memory chips.
SIMS Secondary ion mass spectroscopy
SINGLE TRACK Board technology whereby one track is designed between hole-centers on a DIP.
SIP System in package
SLI System-level integration
SLIP SHEET A protective sheet placed between innerlayers during transport to limit board-to-board contact and scratching.
SMD Surface Mount Device, or, Solder-mask defined.
SME Society of Manufacturing Engineers
SMOBC Solder Mask Over Bare Copper
SMT Surface Mount Technology.
SO-DIMM Small Outline Dual In-Line Memory Module: a small version of a DIMM used commonly in notebook computers. Whereas a full-size DIMM has 168 pins and can support 64-bit transfers, and SO DIMM has only 72 pins and can support only 32-bit transfers. In this respect, it is more like a SIMM, except that it is smaller.
SOIC Small-outline integrated circuits
SOJ Small-Outline J-lead, a type of chip module that uses J-shaped pins that extend inwards. Unlike DIPS, which plug into holes on the circuit board, and SOJ chip attaches directly to the circuit board’s surface.
SOLDER BALLS The round solder balls bonded to a transistor contact area and used to make connection to a conductor by face-down bonding techniques.
SOLDER BUMP Solder balls
SOLDER MASK A technique wherein everything on a circuit board is coated with a non-conductive polymer except the contacts to be soldered, the edge-card connectors and fiducials.
SPC Statistical Process Control.
SQFP Shrink Quad Flat Pack
SRAM Static Random Access Memory: a type of memory that is faster and more reliable than the more common DRAM (dynamic RAM). The term static is derived from the fact that it doesn’t need to be refreshed like dynamic RAM.
SSF Surface Square Foot.
STAR-DUSTING The appearance of copper spotting on the surface of an interlayer
STRONGARM PROCESSORS CPU architecture oriented to embedded low-end requirements originally designed by ARM (a UK based company) but now manufactured under license by Intel and some others.
SUB-PANEL A group of printed circuits (called modules) arrayed in a panel and handled by both the board house and the assembly house as though it were a single printed wiring board.
SUBSTRATE The copper foil laminated fiberglass panel that printed circuit boards are built upon. Also known as an interlayer, panel or core.
SUPPLY CHAIN AND LOGISTICS MANAGEMENT Supply chain management is the ability to ensure a steady flow of materials through the manufacturing process. Logistics management involves the sorting, warehousing, and shipping raw goods and finished products.
SURFACE INSULATION RESISTANCE The measurement of insulation resistance across the surface of an insulation material.
SURFACE MOUNT Surface mount technology. The technology of creating printed wiring wherein components are soldered to the board without using holes. The result is higher component density, allowing for smaller PWB’s.
SURFACE MOUNT TECHNOLOGY A method of soldering electrical components directly to a board substrate that uses less space than the pin-through-hole method.
SURFACE TOPOGRAPHY The physical appearance characterized by either being porous or non-porous.
SYSTEMS DESIGN Ability to do designs that comprise the interaction and integration of various sub-assemblies into a single assembly to accomplish an intended function. The sub-assemblies can consist of electrical, mechanical, optical, software, acoustical and other components to achieve overall functionality. Examples of systems design include designing a PC, a cellular phone or a pager.
SYSTEMS INTEGRATION Combining sub-systems an/or peripherals, adding software and cabling to specification in order to produce fully configured product.