SMT: Glossary Of Terms - C Stage
Glossary of terms
CFC
Chlorinated fluorocarbon, cause depletion of ozone layer and scheduled for restricted use by the environmental protection agency. CFCs are used in air conditioning, foam insulation and solvents, etc.
Chip Carrier
A low-profile rectangular component package usually square whose semiconductor chip cavity or mounting area is a large fraction of the package size and whose external connections are usually on all four sides of the package.
AChip Component
Generic term for any two terminal leadless surface mount passive devices, the term includes diodes inductors, resistors, and capacitors. A 1206 notation specifies the size of the device (0.120â€X0.060â€), with other standard notations being 0805,1210,1812,etc. It is also used for representing ICs.
Chip-on-board Technology
Generic term for any component assembly technology in which an unpackaged silicon die is mounted directly on the printed wiring board. Connections to the board can be made by wire bonding , tape automated bonding (TAB), or flip-chip bonding.
CLCC, Ceramic Leaded Chip Carrier
A ceramic chip carrier whose external connections consist of leads around and down the sides of the package.
Cold solder joint
A solder connection exhibiting poor wetting and a grayish, porous appearance due to insufficient heat, inadequate cleaning prior to soldering , excessive impurities in the solder, and/or poor flux action.
Components
An individual part or combination of parts that, when together, perform a design function(s).
Component lead
The solid or stranded wire or formed conductor that extends from a component and serves as a mechanical or electrical connection or both that is readily formable to a desired configuration.
Component mounting site
A location on a package and interconnection structure that consists of a land pattern and conductor fanout to additional lands/pads for testing or visa’ that are associated with the mounting of a single component.
Component Side
A term used in through-hole technology to indicate the component side of the PWB. See also Primary Side and Secondary Side.
Constellation
Metallized semicircular radial features on the edges of LCCC’s that interconnect conducting surfaces. Constellations are typically found on all four edges of a leadless chip carrier. Each lies within the termination area for direct attachment to the land patterns.
Contact angle
The angle of wetting enclosed within the solder fillet, between a plane tangent to the solder/ base-metal surface and a plane tangent to the solder/air interface. Contact angles of less than 90 are acceptable. Contact angles greater than 90 are unacceptable.
Continuity testing
A procedure in which voltage is applied to two interconnected lands to verify the presence or absence of current flow.
Control Chart
A chart that tracks process performance over time. trends in the chart are used to identify process problems that may require corrective action to bring the process under control.
Coplanarity
Term used to describe the relationship of component leads to each other across the horizontal plane, when the package rests on a perfectly flat surface. The maximum distance acceptable between the lowest and the highest pin is 0.004 inch.
CTE or TCE Coefficient of Thermal Expansion
The linear thermal expansion of a material per unit change in temperature. CTE is commonly expressed in ppm/C.
