Glossary of Terms
Below is a glossary of commonly used terms in the Microelectronics and Packaging Industry.
ADC / Analog-to-Digital Converter
In electronics, an analog-to-digital converter (ADC, A/D, A–D, or A-to-D) is a system that converts an analog signal into a digital signal. A digital-to-analog converter (DAC) performs the reverse function.
An ADC may also provide an isolated measurement such as an electronic device that converts an input analog voltage or current to a digital number proportional to the magnitude of the voltage or current. Typically the digital output will be a two’s complement binary number that is proportional to the input, but there are other possibilities.
There are several ADC architectures. Due to the complexity and the need for precisely matched components, all but the most specialized ADCs are implemented as integrated circuits (ICs).
AOI / Automated Optical Inspection – is an automated visual inspection of printed circuit board (PCB) (or LCD, transistor) manufacture where a camera autonomously scans the device under test for both catastrophic failure (e.g. missing component) and quality defects (e.g. fillet size or shape or component skew).
ASIC / Application-Specific Integrated Circuit – is an integrated circuit (IC) customized for a particular use, rather than intended for general-purpose use. For example, a chip designed to run in a digital voice recorder or a high-efficiency Bitcoin miner is an ASIC. Application-specific standard products (ASSPs) are intermediate between ASICs and industry standard integrated circuits.
CTE / Co-Efficient Thermal Expansion – When materials are heated, their size and volume increase in small increments, in a phenomenon known as thermal expansion. Expansion values vary depending on the material being heated. The coefficient ratio of thermal expansion indicates how much a material expands per 1 oC (2.2 oF) rise in temperature.
Fan-Out – In digital electronics, the fan-out of a logic gate output is the number of gate inputs.
Flexible Electronics – Flexible electronics, also known as flex circuits, is a technology for assembling electronic circuits by mounting electronic devices on flexible plastic.
NRE / Non Reoccurring Engineering – is a one time engineering effort by a vendor that is paid for by a customer. NRE is driven by a feature or capability that a product lacks and a customer wants enough to pay for.
Reballing – A reflow heats up the solder in order to get it malleable enough to reform a broken connection, but the resulting connection still isn’t as strong as it was originally. A reball means that someone completely removes the old solder from the motherboard and chip and reattaches the chip with new solder balls.
RoHS / Restriction of Hazardous Substances Directive – The Restriction of Hazardous Substances Directive 2002/95/EC, (RoHS 1), short for Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment, was adopted in February 2003 by the European Union.
- RoHS is often referred to (inaccurately) as the ‘lead-free directive’, but it restricts the use of the following ten substances:
- Lead (Pb)
- Mercury (Hg)
- Cadmium (Cd)
- Hexavalent chromium (Cr6+)
- Polybrominated biphenyls (PBB)
- Polybrominated diphenyl ether (PBDE)
- Bis(2-ethylhexyl) phthalate (DEHP)
- Butyl benzyl phthalate (BBP)
- Dibutyl phthalate (DBP)
- Diisobutyl phthalate (DIBP)
To ruggedize electronics is to add a level of protection for electronic components to ensure shock and vibration do not cause failure. Electronics overmolding is a specialty of ISI, which is the application of thermoset encapsulation, which is an epoxy overmold process which uses tooling to form a protective barrier around an electronic part.
Wave Soldering – Wave soldering is a bulk soldering process used in the manufacture of printed circuit boards. The circuit board is passed over a pan of molten solder in which a pump produces an upwelling of solder that looks like a standing wave. As the circuit board makes contact with this wave, the components become soldered to the board. Wave soldering is used for both through-hole printed circuit assemblies, and surface mount. In the latter case, the components are glued onto the surface of a printed circuit board (PCB) by placement equipment, before being run through the molten solder wave.