| Term |
Definition |
| P |
back to top |
| Packaging Density |
The number of components, interconnections, and mechanical devices
per unit volume. |
| Pad, Test |
Designated points of access to a circuit or component for testing
purposes.
|
| Pad, Land |
A portion of a conductive pattern used as a termination area.
Metal surrounding a hole on a printed circuit board. |
| Panel |
Printed circuit board. Often used in determining the capacity
of a PWD facility, e.g. "total panels" is a unit of measurement
that refers to the total volume of boards manufactured. |
| Panel Size |
A measurement of the largest possible circuit board that can
be manufactured by a PWB manufacturer. Dictates not only the size
and configuration of the etcher but the processes within the entire
facility. |
| Parametric |
The testing of specific parameters for different inputs and
outputs.
|
| Part |
An element of an assembly, or subassembly that is not normally
subject to further subdivision or disassembly without destruction
of designed use. Examples are: Printed wiring board, resistor, integrated
circuit. |
| Passive Components |
Passive components direct, split, and merge optical signals without
the use of electricity. Passive components are typically constructed
using materials that can transmit lightwaves, including silica,
quartz, and polymers. Primary passive components include couplers,
splitters, isolators, attenuators, circulators and lenses. |
| PCA |
see Printed Circuit Board
Assembly |
| PCB |
see Printed Circuit Board
Assembly |
| PCB Fabrication |
This process consists of fabricating a bare printed circuit board.
Although PCB manufacturing is a capital-intensive process that can
be environmentally sensitive, more EMS providers may add this capability
in an effort to cut costs through vertical integration. |
| PCBA |
see Printed Circuit Board
Assembly |
| PCMCIA |
see
Personal Computer Memory Card Industry Association |
| PCS (Personal Communications
Services) |
Generally, a marketing germ used to describe a wide variety of
two-way digital wireless service offerings in North America operating
at 1900 MHz. PCS services include next generation wireless phone
and communication services, wireless local loop, inexpensive walk-around
communication service with lightweight, low-powered handsets, in-building
cordless voice services for business, in-building wireless LAN service
for business, enhanced paging service as well as wireless services
integrated with wired networks. A Personal Communications System
refers to the hardware and software that provide communications
services.
|
| PDA (Personal Data Appliance/Assistant) |
Portable (handheld) computing device with personal information
management capability. These devices typically combine contact,
task, calendar and notebook functions.
|
| Pelletized |
Form of raw material for Thermo Plastic Injection Molding |
| Personal
Computer Memory Card Industry Association (PCMCIA) |
A trade organization which has produced the standard format for
the credit-card-sized peripherals used with portable computers (to
promote interchangeability of cards among a variety of computer
products). Memory cards from 128K to 2MB - which, with battery backup,
can behave exactly like floppy disk drive (the most common PCMCIA
add-on), but versions of the specification enable devices such as
modems to be added in PCMCIA slots too. |
| Photodetector |
A device that can sense incident radiation (photons). Photodetectors
are critical for detecting the presence of optical power. They are
used in transceivers to receive a transmitted signal and are incorporated
in other devices to monitor optical power and performance. |
| Photolithography |
The photographic process used to transfer circuit patterns onto
a semiconductor wafer. This is done by projecting light through
a patterned reticle, onto a silicon wafer covered with a photoresist. |
| Photon |
A quantum of electromagnetic energy of a single mode; i.e., a
single wavelength, direction, and polarization. As a unit of energy,
each photon equals hn; h being Planck’s constant and n, the frequency
of the propagating electromagnetic wave. |
| Photoresist |
A light sensitive material, liquid or a laminated dry film, which
when selectively exposed to light, masks off areas of the design
that can be etched away |
| Physical
Vapor Deposition (PVD) |
Deposition of thin films by physical means as opposed to chemical
(like chemical vapor deposition). This is most often used for deposition
of metals. The most common form of PVD is sputtering. |
| Pick-and-place |
The automated assembly process that uses NC equipment to precisely
place electronics parts on a circuit board prior to soldering.
|
| Pickers |
Robotic machines used to remove plastic parts from injeciton
molds after molding cycle is complete. Typically simple one or two
axces.
|
| Pigtailing |
A term used to describe the process of attaching a short length
of optical fiber to an optical component to couple power between
it and the transmission fiber. Successful pigtailing involves precise
alignment of the optical components and the fiber to ensure a proper
optical connection. |
| Pin & Paste |
Using SMT processes to solder through hole parts. |
| Pin Grid Array (PGA) |
A PTH package with a large array of leads protruding perpendicular
to one side of a component package. |
| Pinhole |
(1) Soldering: A solder connection with a small hole penetrating
from the surface of the solder to a void of indeterminate size within
the solder connection. (2) Printing: A void that receives no ink,
paste, or gel during printing. |
| Pin-Through-Hole
(PTH) |
A manufacturing technology, where the slender wire leads of components
are inserted through the holes of the printed circuit board. PTH
technology uses more "real estate" on a board and has been replaced
by SMT as the component placement method of choice by the EMS industry. |
| Pitch |
(1) The center-to-center spacing between the leads of a component.
(2) Distance between pockets on a carrier tape. Pitch varies according
to tape width and components packed on the tape. (3) The center
to center distance of two adjacent sprocket holes. |
| Placement |
The manual, semiautomatic, or automatic location of a component,
device, or chip at its intended position. |
| Planar Waveguides |
A planar waveguide is a waveguide fabricated using semiconductor-based
fabrication techniques in which a waveguide is embedded in a planar
structure. Planar waveguides are used to manufacture arrayed waveguide
gratings, couplers/splitters, and are being increasingly used as
high density interconnects. |
| Plastic Assembly |
General name for adding additional manufacturing processes to
the molded part process.
|
| Plastic Ball
Grid Array (PBGA) |
A Ball Grid Array (BGA) package of high Tg material substrate
and encapsulated with either a plastic overmold or globtop. An array
of eutectic (63Sn/37Pb) 0.77 mm diameter balls provide the interconnection
to the printed circuit board. These balls reflow during package
and printed circuit board assembly and provide a 50 mm gap or standoff
between the chip carrier and the glass epoxy board. |
| Plastic
Leaded Chip Carriers (PLCC) |
A SMT package with 50 mil spaced J-leads on all four sides that
have the same dimensions. |
| Plastic Molding |
The manufacturing process of producing plastic parts.
|
| Plated Through
Hole or Pin Through Hole (PTH) |
A plated-through hole is one formed by a deposition of metal
on the inside surface of a through-hole. Also known as a supported
hole. The configuration is used to provide additional mechanical
strength to the soldered termination or to provide an electrical
interconnection on a multilayer printed circuit board. |
| Plating, Additive |
A process in which the conductive, resistive, and insulating
materials are successively plated to define traces, pads, and elements. |
| Plating, Electroless |
Plating as the result of chemical action (without any external
electric current). |
| Plating, Electrolytic |
Plating deposited by application of electrical current. |
| Plating, Lead |
The metal coating on a component lead. Common lead plating materials
are pure tin (Sn), pure gold (Au), and eutectic tin/lead solder
(63%Sn/37% Pb). |
| Plating, Tin Lead |
In printed circuit board fabrication, an electroless plating
process that coats exposed areas of copper on a circuit board with
a layer of tin lead alloy to prevent the copper from oxidizing. |
| PLC |
Programmable Logic Controller |
| Plowing |
In printed circuit board fabrication, the furrows in the walls
of a drilled hole. |
| Plug (ing) |
A printed circuit board fabrication process that fills vias to
prevent heat conduction and chemical transport through the via and
to allow vacuum hold-down during automated testing. |
| Polarization |
A term used to describe the orientation of the electric and magnetic
field vectors of a propagating electromagnetic wave. Polarization
of a lightwave signal becomes increasingly important at higher transmission
speeds and in higher channel count DWDM systems and can lead to
dispersion and other signal degrading effects. |
| Polymer |
A material whose molecular structure consists of long chains
made up by the repetition of many (usually thousands) similar groups
of atoms. Different polymers are being explored for use in fabricating
monolithic integrated optical devices. |
| Potting |
see Encapsulating |
| Potting Compound |
An electrically nonconductive compound used to partially encapsulate
or for a filler between parts, conductors, or assemblies. |
| Power Supply
Assembly |
This process consists of assembling a power supply which is responsible
for regulating, supplying and distributing electrical power to electronic
products,. The primary types of power supply include DC/DC and AC/DC. |
| PPM |
Parts per million |
| PQFP |
Plastic Quad Flat Package |
| Preflow. Soak |
The portion of a reflow profile after preheat and before the
reflow spike occurs. During this time, the temperature of the metals
being joined is allowed to equalize. |
| Primary Side |
The side of the printed circuit board that contains the most
or more complex components. |
| Printed
Circuit Board Assembly (PCBA) |
PCB assembly consists of attaching passive components (e.g.
ceramic capacitors, tantalum capacitors, resistors) and active components
(e.g. memory, microprocessor, surface acoustic wave filters) to
the surface of a PCB. Components from a few hundred to many thousands
can be attached to a single PCB. Initially, solder paste is applied
to the PCB before a "chip-shooter" (i.e. a surface mount technology
machine that quickly place components on a PCB) places components
on the board (high-volume applications) at a rate of more than 40,0000
chips per hour (or higher). |
| Printed Circuit
Board |
The backbone of an electronic system. A PCB consists of a pattern
of electrical traces etched from copper that are laminated on an
insulated base, which is typically rigid fiberglass. It serves as
the interconnection device, with electrical currents traveling on
the board to the different discrete components (i.e. passive components
and semiconductors) that are essential to the functioning of electronic
equipment. |
| Printed Wiring
Assembly (PWA) |
Abbreviation for "printed wire board" or "printed circuit board |
| Probe |
(1) A rigid, pointed, metallic, wire-shaped device used for making
electrical contact to a circuit pad for electrical test purposes.
(2) A metal scribe. |
| Process |
A process may be a single method or procedure, or may be made
up of sub processes and activities. Wave soldering is a process. |
| Process
Capability. Competence |
A measure of the process variation about a defined target value.
Cp and Cpk are common process characterization indexes. |
| Process Control.
|
Automatic monitoring and control of a process by an instrument
or system configured or programmed to respond appropriately to process
feedback. |
| Process
Failure Mode Effect Analysis (PFEMA). |
FEMA applied to production processes. |
| Process Management |
Prevents defects by fulfilling individual responsibilities instead
of reacting to defects as the result of not fulfilling them. The
goal of process management is consistent product quality. |
| Process Simulation |
Use of a mathematical model by a computer program to implement
different process design scenarios with real-time feedback. |
| Procurement |
The steps necessary in purchasing materials for manufacturing. |
| Product Life Cycle |
Encompasses fabrication, assembly, test, storage, transportation
and operation of a product. |
| Product upgrades |
This process consists of upgrading an OEM customer's product,
without the OEM getting involved. EMS providers must have the requisite
engineering skills and components to upgrade the product. |
| Production Control |
Systematic planning, coordination and direction of all manufacturing
activities to ensure that products are made on time, of adequate
quality and at reasonable cost. |
| Production Design |
This CAD layout operation helps customers to design or redesign
the layout of a circuit board in order to improve its manufacturability
and reduce the manufacturing time of assembled circuit boards. The
design staff works closely with the customer and circuit board fabricator
to make the product easier to manufacture and test, which lowers
production costs and improves the quality of the product. |
| Production Master |
In printed circuit board fabrication, a 1:1 scale pattern of
the features to be produced on a layer of the board. |
| Profiler |
A tool to aid in measuring and recording thermal profiles of
soldering processes. |
| Protocol |
A protocol is essentially a common set of rules that allows electronic
devices to communicate with one another. Common communications protocols
include Internet Protocol (IP), Asynchronous Transfer Mode (ATM),
Synchronous Optical Network Technology (SONET), and many others. |
| Prototyping |
The process of refining and testing the design and functionality
of a new product by building initial quantities in small batches.
Most leading EMS providers have smaller facilities dedicated to
prototype production. |
| PWA |
see Printed Wiring Assembly |
| PWB |
see Printed Wiring Board (Printed
Circuit Board) |
| Q |
back to top |
| QA |
Quality Assurance |
| QC |
Quality Control |
| QFN Package |
Quad Flat No Lead Package.
|
| QFP |
Quad Flat Pack |
| QFP-N |
Quad Flat-Pack No-lead (JEDEC) package |
| QS 9000 |
A more stringent standard than the ISO9000 series, which was
developed by the Big Three auto manufacturers: Ford, Chrysler, and
General Motors. The original purpose was a focus on tier 1 suppliers,
which used the ISO9000 and added aspects of their own three quality
systems.
|
| Quality |
Conformance to clearly specified, understood, and accepted customer
contract requirements. |
| Quick-turn
prototyping |
Ability to produce a sample of a product in a relatively short
time. For example, assembling a print circuit board in 48 hours
from receipt of all the board-level components. |
| Quick-turn testing |
Verification of a product using test methods that are easy to
implement, e.g. fixtureless test using a flying probe tester. |
| R |
back to top |
| R&D |
Research and Development |
| Radio
Frequency Interference (RFI) |
(1) Computers, like other electronic devices, must be constructed
so as not to allow the emission of frequencies that might cause
interference with radio or television reception. Good design can
minimize the problem, but you will often see additional metal shielding
inside a computer or the use of a metal case. Conversely, RFI generated
from any nearby frequency-emitting sources such as radio or TV transmitters
or CB radios can sometimes cause problems with a computer. [EMC,
EMI, FCC]
(2) Electromagnetic waves in the frequency range of 30 kHz to 300
GHz. |
| RAID |
Redundant Array of Inexpensive Disks. Originally, a method of
replacing the very large (and very expensive) 14" disk drives used
on mainframe computers with arrays of the smaller (e.g. 5.25") hard
disk drives used by PCs. Today, the Raid system is being used with
networked PCs. There are various Raid levels which involve different
hardware configurations, but the basic idea is that the data saved
is shared among a number of drives; if one of the drives should
become corrupted or fail, the data can be reconstructed from the
contents of the other drives. It may even be possible to replace
a failed drive without turning off the system or making users aware
that anything is wrong. A Raid system provides greater reliability
and security of data than a single, large-capacity hard drive [HD,
LAN, Wan]. |
| Real-Time System |
Use of precise timing in controlling an event typically consisting
of multiple changing variables. |
| Reconfiguration |
Upgrading an existing product by replacing subsytems, peripherals,
software or cabling. |
| Reflection |
In the context of optical fiber communications, is a location
along a fiber where a fraction of the light signal reverses direction
and returns to the source. Reflections are generally undesirable
and can lead to degradation of a network, either by inducing loss
and/or by causing instabilities in the optical source. |
| Reflow |
A manufacturing process that consists of applying heat to solder
paste to form a solder joint. |
| Reflow Oven |
A type of manufacturing equipment which applies heat to a surface
containing a thin deposit of a low melting point metal or alloy
(e.g., solder paste tin lead alloy), resulting in the melting of
the deposit, followed by its solidification.
|
| Reflow Soldering |
(1) The remelting and resolidification of solid or paste solder
to form an electrical connection.
(2) A process in which solder paste is deposited upon pre-tinned
pads on a PCB and the component's pre-tinned leads are placed
upon the paste. When the assembly is heated to the proper temperature,
the solder paste melts and the solder on the leads and pads reflows
to form a solder fillet.
|
| Reflow
Soldering, Conduction |
A conduction reflow soldering machine that uses moving hot air
or inert gas (nitrogen) to envelope the entire printed circuit assembly. |
| Reflow
Soldering, Double Sided |
Reflow soldering of components on both sides of a printed circuit
assembly. |
| Reflow
Soldering, Infrared (IR) |
An IR reflow soldering machine that uses heat radiation to warm
the entire printed circuit assembly. |
| Reflow
Soldering, Vapor Phase |
Vapor Phase Soldering |
| Reliability |
The continued conformance of a device or system to a specification
over an extended period of time. |
| Reliability
and Failure Analysis |
Capability to determine the root cause of a component or assembly
defect or failure as well as to predict the lifeof a board or system. |
| Reliability Test |
This is usually expressed in terms of mean time between failures
(MTBF). |
| Remote Fiber
Test System (RFTS) |
A permanently installed fault surveillance system in which test
equipment is connected to a communications network. Strategically
located remote test units continually check optical links and send
test data to a centralized test system controller. Upon detecting
a problem, the system sends out an alarm to a repair crew. |
| Repair and
Maintenance |
Repair, refurbishment, remanufacturing, upgrades, test and burn-in,
component debug, field ready pack out, direct ship, RMA control,
advanced exchange, DGI management, EC management, data recovery,
failure analysis, material recovery. |
| Repair, Board-Level
(Circuitry) |
A process where the printed circuit board must be repaired in
addition to the possible removal and replacement of parts. This
may include fixing a damaged land, trace or via. It is most often
carried out using manual techniques. |
| Repair,
Component-Level |
A process for removing defective components and replacing them
with working components. It is typically carried out using manual
or semiautomated techniques. |
| Repair/Refurbishment |
EMS provider takes responsibility for repairing a product. An
agreement can consist of the EMS provider visiting the end-user
to repair the product, or the end-user going to the EMS provider. |
| Repeatability |
Precision. The ability to produce consistent results. Gauge Repeatability. |
| Reproducibility |
The ability to obtain consistent results when repeating a measurement
or operation at different times and/or with different operators
and/or using different instruments/tools of the same type. Gauge
Reproducibility |
| Resin |
(1) In soldering: a chemically synthesized resin. (2) In water
processing: an ion exchange product, usually organic polymer beads
used in softening and other ion exchange processes to remove dissolved
salts from water. (3) In adhesives: an organic polymer which, when
mixed with a curing agent, crosslinks to form a thermosetting plastic. |
| Resistors |
A device used in an electrical circuit to provide resistance
|
| Reverse Logistics |
Manages the reverse flow of defective product from the end user
through the various steps to repair and then back out to the end
user. Will involve inventory management, remote stocking location
management/re-provision, advanced exchange, warehousing, external
shipping/receiving, freight carrier management, scheduling, forecasting,
import/export, freight data collection, turnaround time metrics. |
| Revolver Head |
see Turret Head |
| Rework |
The reprocessing of an article or material to make it conform
to drawings, specifications, and purchase order. |
| RF |
see Radio Frequency |
| RFI |
see Radio Frequency Interference |
| RFTS |
see Remote Fiber Test System |
| RH |
Relative Humidity |
| Rigid Flex |
A fabrication construction that combines a standard printed circuit
board (rigid) with flexible printed circuit. |
| RMA |
Return Materials Authorization (Warranty Repair). |
| RMA Flux |
Resin Mildly Activated Flux.
|
| ROSE |
Resistivity of solvent extraction.
|
| Router |
(1) In CAD: A computer program that determines the paths between
interconnecting points. (2) In printed circuit board fabrication
and assembly: A printed circuit board fabrication machine that grinds-away
portions of the laminate. |
| S |
back to top |
| SAM |
see Scanning Acoustic Microscopy |
| SBGA |
Super Ball Grid Array |
| Scanning
Acoustic Microscopy (SAM) |
Scanning Acoustic Microscope (or surface acoustic microscope) |
| Scanning
Electron Microscope (SEM) |
A microscope that uses electrons rather than light to form an
image. The advantages of a SEM over a light microscope are: (a)
a large depth of field, which allows a large amount of the sample
to be in focus at one time. (b) high resolution images, which means
that closely spaced features can be examined at a high magnification.
Most SEMs require the sample to be conductive, but preparation of
the samples is relatively easy. |
| Schematics |
A schematic diagram is the engineer’s tool for depicting
the electrical design’s devices and connections in a common
format of symbols and connection lines.
|
| Scoring (V-Scoring) |
A technique allowing the separation of each printed circuit board
from a fabricated array. |
| Screen Printer |
Transfer of a pattern onto a surface by forcing a suitable material
through a screen with a squeegee
|
| Screen Printing |
The transfer of a pattern onto a surface by forcing a suitable
material through a screen with a squeegee. |
| Secondary Operation |
Secondary operations General name for adding additional manufacturing
processes to the molded part process.
|
| Secondary Side |
That side of the printed circuit board that is opposite of the
primary side (solder side in PTH technology). |
| Selective
(Wave) Soldering |
see Wave
Soldering, Selective |
| SEM |
see Scanning Electron Microscope |
| SEMATECH |
Semiconductor Manufacturing Technology Consortium |
| Semiautomated
Assembly |
A process for the manufacture of an electronic assembly carried
out by an operator with a combination of manual and automated equipment. |
| Semiconductor |
A substance, as germanium, used as in transistors
|
| Semiconductor
Laser |
An optoelectronic device typically fabricated from a compound
semiconductor material that can emit coherent light through electrical
stimulation. Semiconductor lasers are used as signal sources as
well as for energy sources to amplify an optical signal. Distributed
feedback (DFB), Fabry-Perot, and light emitting diodes (LED) are
different types of lasers used for communications. Semiconductor
lasers can also be either edge emitting or vertical emitting (VCSEL). |
| Sequential
Electrochemical Reduction Analysis (SERA) |
A non-destructive technique that characterizes solderability,
surface metal oxides, and intermetallics. |
| SERA |
see Sequential
Electrochemical Reduction Analysis |
| Short |
An undesired electrical connection caused by either (1) a bridge
between trace paths on a printed circuit board or (2) solder bridging
the gap between lead terminations or pads. |
| SIA |
Semiconductor Industry Association |
| Silk Screen |
see Legend |
| Single Inline
Package (SIP) |
A PTH package with one row of leads extending from the base of
the component. Standard lead pitch is 0.100 inch. |
| Single Layer Board |
A printed circuit board that contains metallized conductors on
one side of the board and no plating in the through holes. |
| SIP |
Single Inline Package |
| SIR |
Surface Insulation Resistance
|
| SLA (Stereolithography) |
A method of making a 3D plastic part from a CAD database, usually
done as a preliminary model.
|
| SLC |
Single Layer Ceramic (capacitor) |
| SMA Wire (Shape Memory
Alloy) |
A wire that contracts like muscles when electrically driven and
is used like a solenoid.
|
| Small
Outline Integrated Circuit (SOIC) |
An integrated circuit SMT package with two parallel rows of 8
to 16 gull-wing leads. The pitch is 50 mil. |
| Small
Outline J leaded devices |
An integrated circuit SMT package with two parallel rows of 16-40
J leads. The pitch is 50 mil. |
| Small
Outline Large Integrated Circuit (SOLIC) |
An integrated circuit SMT package with two parallel rows of 8
to 28 gull-wing leads. The pitch is 50 mil. |
| Small Outline
Transistor (SOT) |
A discrete SMT package with two gull-wing leads on one side of
the package and one gull wing lead on the other side. |
| Smart Media |
A small memory device commonly used in digital cameras and consumer
electronics.
|
| SMC |
Surface mount component |
| SMD (Surface Mount Device) |
Electronic components, either active (transistors, IC's, diodes,
etc.) or passive (capacitors, resistors, coils, etc.) that do not
have wire leads or pins. The terminal leads are part of the component
body, thus allowing direct mounting on the surface of printed circuit
boards. Leaded devices are mounted by their leads through holes
drilled in the boards. In both cases, the components are held in
place on the boards, both mechanically and electrically, by solder.
Surface mounted components usually are smaller than an equivalent
through-hole leaded device and, in some cases, less expensive. Equipment
and design engineers can save valuable wiring board area by mounting
surface-mounted leadless components on the underside of a board,
and conventional leaded components on the top side of boards. |
| SMTA |
see Surface Mount Technology |
| SMTA |
Surface Mount Technology Association |
| SOIC |
see Small Outline
Integrated Circuit |
| SOJ |
see Small Outline J leaded
device |
| Solder |
A fusible metal alloy, consisting primarily of tin and lead,
used for the purpose of joining together two or more metals at a
temperature below their melting point. Bar, wire, and paste are
common forms of solder. |
| Solder Alloy |
Combination of low melting point metals (usually consisting
primarily of tin and lead) that can wet copper, conduct current,
and mechanically join conductors.
|
| Solder Balls |
(1) A soldering process residue consisting of small spheres on
the printed circuit board surface. (2) Solder bumps. |
| Solder Bridge (ing) |
Short. An unplanned solder connection. |
| Solder Bump |
Solder spheres bonded to pads of components, used for face-down
bonding. |
| Solder Connection |
Solder Joint. |
| Solder Joint |
An electrical/mechanical connection that uses solder to join
two or more metal surfaces. |
| Solder Joint,
Cold |
A solder connection exhibiting poor wetting and a grayish, porous
appearance due to insufficient heat, inadequate cleaning before
to soldering, or excessive impurities in the solder. |
| Solder Leveling |
A printed circuit board fabrication process in which hot air
or gas “smooths” or removes excess solder on formed joints. |
| Solder Mask |
Coating material used to mask or protect selected areas of a
pattern from the action of an etchant, solder, or plating. |
| Solder Pad |
Termination area on a printed wiring conductor. Land. Pad. |
| Solder Paste |
A homogeneous combination of solder particles (ranging in diameter
from about 4 to 40 microns), flux, solvent, and a suspension agent
used in the surface mount reflow soldering process. Solder paste
has a high viscosity of approximately 900,000 centipoise. Solder
paste is commonly applied by printing, dispensing, preforms, and
manual methods. |
| Solder Sucker |
A device used to remove molten solder during rework.
|
| Solder, Eutectic |
A solder alloy with eutectic composition.
|
| Solder,
High Temperature |
Solder with a high melting temperature. For example: 10Sn/88Pb/2Ag
is liquidous at 290°C(554°F), compared with eutectic solder which
is liquidous at 183°C(361°F). |
| Solder, Low
Temperature |
Solder with a low melting temperature. For example: 43Sn/43Pb/14Bi
is liquidous at 163°C(325°F), compared with eutectic solder which
is liquidous at 183°C(361°F). |
| Solderability |
(1) The property of a surface that allows it to be wetted by
a molten solder. (2) The ease with which solder adheres to a basis
metal surface such as a component lead, solder termination pad,
or conductor hole pad and wall. Surface oxides and intermetallics
interfer with solderability. |
| Soldering |
(1) The method for mechanically and electrically joining two
metals using an alloying metal (solder), a cleansing agent (flux),
and heat without direct fusion of the base metals. (2) Metallurgical
joining two metal surfaces using a metal filler with a melting point
below 800°F (some say 500°F) without diffusion or intermetallic
formations (some say). |
| Soldering Iron |
A device used to solder.
|
| Solenoid |
An electro-mechanical device used as an actuator is a linear
direction.
|
| SOLIC |
see Small Outline
Large Integrated Circuit |
| Solvent |
A liquid used to clean materials. |
| SOC |
System on chip.
|
| SON |
see
Small Outline No-Lead (IC package) |
| SOP |
System on package.
|
| SOT |
Small Outline Transistor |
| SPC |
see Statistical Process
Control |
| Special Process |
The results of special processes cannot be verified fully by
subsequent nondestructive inspections. Soldering, brazing, and welding
are examples of special processes. |
| SQC |
see Statistical Quality
Control |
| Staking Compound |
An electrically nonconductive adhesive material used for additional
support after a component has been attached by mechanical or soldering
process. |
| Statistical
Process Control (SPC) |
A quality control method that focuses on continuous monitoring
of the process with the intent to achieve closed loop control of
the process to eliminate defective product. |
| Statistical
Quality Control (SQC) |
Applies statistical techniques to the observed characteristics
of a process. |
| Stencil |
A thin sheet of brass or stainless steel with openings that match
the land pattern of the printed circuit board. During printing,
adhesive or solder paste is forced through these openings onto the
printed circuit board. |
| Step & Repeat |
A process where the printed circuit board layout or component
placement is repeated many times in evenly spaced rows. |
| Sub-assemblies |
The act of assembling several parts into on part that will be
used in a larger assebly of product.
|
| Substrate |
A supporting insulating material upon which parts, substrates,
and elements are attached. |
| 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. |
| Support Services |
These services include warranty services, depot repair, refurbishment,
product upgrades, help-desk support and failure diagnostics. |
| Supportive (ed)
Hole |
A hole in a printed circuit board that has its inside surface
plated or otherwise reinforced. |
| Supply Chain |
A network of organisations that are involved, through upstream
and downstream linkages, in the different processes and activities
that produce value in the form of products and services in the hands
of the ultimate consumer (Christopher, 1992). Can also be used to
refer to the inbound processes resulting in raw materials being
delivered to the production floor.
|
| Surface
Acoustic Microscope (SAM) |
Scanning Acoustic Microscope. Acoustic Microscope |
| Surface Mount
Component (SMC) |
A component designed to be mounted and soldered to pads on the
surface of a PCB rather than inserted into through-holes in a PCB. |
| Surace Mount Device
(SMD) |
Electronic components, either active (transistors, integrated
circuits, diodes, etc.) or passive (capacitors, resistors, coils,
etc.) that do not have wire leads or pins. The terminal leads are
part of the component body, thus allowing direct mounting on the
surface of printed circuit boards. Leaded devices are mounted by
their leads through holes drilled in the boards. In both cases,
the components are held in place on the boards, both mechanically
and electrically, by solder. Surface mounted components usually
are smaller than an equivalent through-hole leaded device and, in
some cases, less expensive. Equipment and design engineers can save
valuable wiring board area by mounting surface-mounted leadless
components on the underside of a board, and conventional leaded
components on the top side of boards. |
| Surface
Mount Technology (SMT) |
A manufacturing process that attaches components on the surface
of the printed circuit board, rather than inserting components into
plated through holes. It uses less space than the pin-through-hole
method. |
| Surface
Mount Technology Association (SMTA) |
A SMT industry promotional and educational organization. |
| Synchronous
Optical Network Technology (SONET)/Synchronous Digital Hierarchy |
An interface standard widely used by the telecom industry to
move data. SONET is the North American version and SDH is the European
version. |
| Systems integration |
Combining sub-systems and/or peripherals, adding software and
cabling to specification in order to produce fully configured product. |
