A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

These are some of the most commonly used words and terms when talking about the layout, manufacture or assembly of the printed circuit board.


A

Annular Ring This is the amount of metal from the drill hole to the edge of the metal pad. The Inner layer annular ring is measured from the edge of the material where the drill tool cut through to the edge of the pad. The Outer layer annular ring is measured from the plated edge inside the hole to the edge of the pad including the finish platting wrap if any.
Au This is the symbol for Gold which is a chemical element that is highly conductive

AOI Automated Optical Inspection

Aperture List This is the ASCII list (Decodes List) of features it includes the sizes and shapes that are used in the data file. 

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B

Barrel This is the term for the walls of the plated hole

bead of nailsBed of Nail Tester these test machines normally use fixtures and pins. These pins make contact with the machine and the circuit board being tested. There are machines for bare circuit boards and loaded (assembled) circuit boards.

 

 

BGA Ball Grid Array is a type of surface mount chip carrier used for integrated circuits. It provides more interconnection pins than a flat package or a  dual inline package.

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C

Copper, when not tarnished, is a pinkish-orange color chemical element with the symbol Cu and atomic number 29, It is a soft metal with very high thermal and electrical conductivity had become the main choice for creating the conductive layer pathways (circuit paths) built into a circuit board

Core is the term used for the base material (dielectric) used in a circuit board it can be used for almost all material types

 

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D

Dielectric, this is the base material that is used as an isolator between conductive layers (also known as a core)
Dry Film Solder Mask
is of a non-conductive material that is applied as a solid film that is photo imagable. It is used to cover the conductive metal traces (normally copper) of a printed circuit board. Its main use is to prevent solder surface shorts between close features and to protect against oxidation. The common color is Green (flat or gloss)

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E

ENIG Electroless Nickle Immersion Gold
ENIPIG Electroless Nickle, Immersion Palladium, Immersion Gold
Extended Gerber This is also known as RS-274x Gerber Data. the "X" means that it has the aperture list embedded in the electronic data file. This file also includes data format (number of digits left and right of the Decimal) as well as the data units (inches/metric)

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F

Flying Probe Tester is a machine that tests the netlist by using several probes that move quickly from point to point.

Foil a thin layer of metal material like copper or aluminum it can be created by the rolled and annealed process or electrodeposited (ED copper)

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G

Gerber is the name of a standard ASCII data format used by electronic circuit board manufacturers. The Gerber format has two main versions RS-274d and RS-274x. This Gerber language is a normal output from most Electronic CAD Layout software. The RS-274d is not used much these days (old version) as it has to have a separate aperture list (adding the potential for mistakes in the interpretation of the file when it is read into PCB CAD software. The RS-274X (aka. Extended Gerber) has the aperture list embedded in the file. This data language is not considered to be a smart format as the data is just the simple ASCII list of XY locations and feature sizes

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H

HAL Hot Air Level, this is shiny (silver in color) finish of solder that is applied by a machine that dips the PCB panel into molten solder (lead or Leadfree) and leveled by high-pressure air being blown across the surfaces
HASL Hot Air Solder Level, this is shiny (silver in color) finish of solder that is applied by a machine that dips the PCB panel into molten solder (lead or Leadfree) and leveled by high-pressure air being blown across the surfaces

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I

ICT (In-Circuit Test) these machines are very similar to the flying probe testers

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J

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K

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L

LDI Laser direct imaging, this machine uses a laser to expose a resist or LPI product. in the older days, we used a Photo Image exposure unit to do the same thing but it was not nearly as accurate and didn't have the capability to auto-scale based on the product

Legend (Silk Screen) is the text letters and symbols that are printed on the outside of printed circuit boards. It is used during the assembly process and by end-users (service persons) to help identify the components, test points, or other important markings. These markings may be part numbers, revisions, assembly numbers, company logos, warning symbols, date codes, and any other identification symbols. The legend can be printed or screened in several colors like black, red, yellow, and blue but the normal is still white.

LPI Liquid Photoimageable, nowadays this type of product is exposed using an LDI machine and is usually talking about resist masks, silkscreens, solder masks

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M

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N

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O

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P

Peelable Mask This is a great product when you need to temporarily cover something during PCB manufacture or Assembly. It is applied as a liquid but when it is dry you can just peel it off and the surface below is protected

PWB Printed Wire Board

PCB Printed Circuit Board

PCBA Printed Circuit Board Assembly

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Q

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R

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S

SilkScreen see legend

Solder is a fusible conductive metal alloy (normally a combination of lead/Tin) used to create a permanent bond between metal pieces.

Solder Mask is a thin coating or film that is of a non-conductive material that is applied as an epoxy liquid (LPI & peelable) or solid (dry film photoimagable) to cover the conductive metal traces (normally copper) of a printed circuit board. Its main use is to prevent solder surface shorts between close features and to protect against oxidation. Common liquid colors available are the common Green (flat or gloss), or the specialty colors Blue, Red, Yellow, Black, and White.

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T

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V

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W

wirewrapWirewrap Was invented to wire telephone crossbar switches and later adapted to construct electronic circuit boards in the 1960 and 1970s. The wire wrap is created by using a special tool or machine to tightly wrap a small gauge solid wire (30-28 gauge) around the sharp corners of a square connection post. 

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X

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Y

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Z

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