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GLOSSARY of Printed Circuits

by John Walt Childers, IPC-CID, Founder of Golden Gate Graphics

   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   

Pronunciation Key

Golden Gate Graphics in an official Altium Service Bureau

Golden Gate Graphics is an official Altium Service Bureau

Terms that contain digits are alphabetized as if the numeric characters were spelled in English.

Terms with two or more words are alphabetized "dictionary style." They are alphabetized as though the spaces between the terms have been removed.
   If there are other characters in the term, such as a slash (/), these are treated the same as spaces and ignored for the purpose of alphabetizinig.

TOP       F

Index to terms on this page:

fabrication drawing   FBGA   FC  
fine line design  
fine pitch   finger   flash  
flex circuit   flexcircuit  
flexible circuitry  
flexible printed circuit   flip-chip  
first article   foil   footprint   FPC   FR-1   FR-2   FR-4   FR-6  

fab — Short for fabrication.
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fabrication drawing — A drawing used to aid the construction of a printed board. It shows all of the locations of the holes to be drilled, their sizes and tolerances, dimensions of the board edges, and notes on the materials and methods to be used. Called "fab drawing" for short. It relates the board edge to at least on hole location as a reference point so that the NC Drill file can be properly lined up.
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FBGA — (EF-BEE-GEE-AY)  Pronunciation Key  noun  [Components] Fine-pitch Ball Grid Array or designated by Altera as Fine-line Ball Grid Array. In practice this refers to ball grid arrays with ball pitches of 1mm or less, but larger than 0.5mm.
A BGA with 0.5mm or less ball pitch is called MBGA (Micro Ball Grid Array). An intermediate ball pitch of 0.8mm is called by many an FBGA, while Altera refers to this as UBGA, meaning Ultra FBGA.
   IPC-7351B footprint naming convention: BGA+Pin Qty+C+Col Pitch X Row Pitch P + Ball Columns X Ball Rows_Body Length X Body Width X Height-N
BGA Note: C = Collapsing balls.
N = Nominal Material Condition (Could also be M for Most or L for Least)
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FC — Flexible Circuit, flexible circuitry, flexcircuit or flex circuit.
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fine line design — Printed circuit design permitting two (rarely three) traces between adjacent DIP pins. It entails the use of a either dry film solder mask or liquid photoimageable solder mask (LPI), both of which are more accurate than wet solder mask.
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fine pitch — Refers to chip packages with lead pitches below 0.050". The largest pitch in this class of parts is 0.8mm, or about 0.031". Lead pitches as small as 0.5mm (0.020") are used.
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finger — A gold-plated terminal of a card-edge connector. [Derived from its shape.]
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flash — 1. v. To turn a vector photoplotter lamp on for a brief but precise duration and then off, during which time the relative positions of the lamp and film remain fixed. This exposes the film with the image of a small object (the size and shape of which is controlled by the transparent portion of an aperture ).  2. n. A small image on film created in such wise or as directed by a command in a Gerber file.) The maximum size (x or y dimension)for a flash varies from one photoplotting shop to another, but is commonly ½ inch.
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flex circuit — Flexible circuit, or flexcircuit; a printed circuit made of thin, flexible material. For more information, see flexible circuitry.
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flexcircuit — See flex circuit.
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flexible circuitry — An array of conductors bonded to a thin, flexible dielectric. It has the unique property of being a three-dimensional circuit that can be shaped in multiplanar configurations, rigidized in specific areas, and molded to backer boards for specific applications. As an interconnect, the main advantages of flex over traditional cabling are greater reliability, size and weight reduction, elimination of mechanical connectors, elimination of wiring errors, increased impedance control and signal quality, circuit simplification, greater operating temperature range, and higher circuit density.
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flexible printed circuit Flex circuit. Abbreviated FPC or FC.
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flip-chip — A mounting approach in which the chip ( die ) is inverted and connected directly to the substrate rather than using the more common wire bonding technique. Examples of this kind of flip-chip mounting are beam lead and solder bump.
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first article — A sample part or assembly manufactured prior to the start of production for the purpose of ensuring that the manufacturer is capable of manufacturing a product which will meet the requirements.   [Graf]
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foil — A sheet of copper of various thicknesses used most commonly as an outer layer in the construction of a PCB stack-up (q.v.).
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footprint — (FUUT print)  Pronunciation Key 

  1. noun  [PCB Manufacturing] The pattern and space on a printed board taken up by a component.
  2. noun  [PCB Layout] A graphic software (artwork) representation of the pattern and space on a printed circuit board taken up by a component, with special handling for the portions for solder to attach. On a manufactured board the body of a footprint is represented is an epoxy-ink outline and the terminals as exposed metal.
       In Altium Designer, a footprint can have a 3D body.
       Footprints are designed by the PCB designer based on datasheets from manufacturers. Also called a land pattern, the footprint forms the pattern of exposed metal on a PCB that allows the component to be soldered. If the component is a through-hole type, the footprint includes numerical controlled drill data, so that the holes that the leads get inserted into are available and in a pattern that fits the component. Footprints in artwork become patterns on manufactured PCBs and should be carefully vetted so that errors don't occur during assembly.
       A footprint is given a name by the PCB designer when he builds it. The name of a footprint is customarily a description of its size and shape and can also include an abbreviation standing for the category of electrical function of its corresponding component. E.g. CAP, RES, DIO or LED for capacitor, resistor, diode or light emitting diode respectively.
       Also called a Decal, because hand tape-up of printed circuit boards employed the use of pull-off and paste decals to represent components.
       Also called a part or package.
       The derivation of the term is intuitive and metaphorical. In forensics, a footprint made by a person can be matched to his shoe and place him at the scene of a crime. In PCB manufacturing, the footprint had better match the component or someone is in trouble.

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FPC — Flexible Printed Circuit, or flex circuit.
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FR-1 — A low-grade version of FR-2.
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FR-2 — A NEMA grade of Flame-Retardant industrial laminate having a substrate of paper and a resin binder of phenolic. It is suitable for printed circuit board laminate and cheaper than the woven glass fabrics such as FR-4.
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FR-4 — A NEMA grade of Flame-Retardent industrial laminate having a substrate of woven-glass fabric and resin binder of epoxy. FR-4 is the most common dielectric material used in the construction of PCBs in the USA.  Its dielectric constant is from 4.4 to 5.2 at below-microwave frequencies. As frequency climbs over 1 GHz, the dielectric constant of FR-4 gradually drops.
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FR-6 — Fire-Retardant glass-and-polyester substrate material for electronic circuits. Inexpensive; popular for automobile electronics. [Stammtisch Beau Fleuve Acronyms]

An article written in 2017 by Atar Mittal of Sierra Circuits is worth study if you need to choose PCB materials for your electronics project. It includes a "Laminate Selector Chart" entitled "PCB Material Properties and Recommended Application Areas" HDI PCBs: Choosing The Right Material

A comparison of many brands of PCB laminates can be found in the Standard Printed Circuits   "Microwave Laminates Comparison Chart."

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Example Printed Boards

Click for Examples of PCBs designed by Golden Gate Graphics

References and Dictionaries

Modern Dictionary of Electronics by Rudolf F. Graf

This is the best, most usable dictionary for electronics, because its definitions help you grasp the terms and therefore the subject. Lesser dictionaries define electronics terms with even more difficult technical jargon, leading one into endless "word chains." Not this one.
You can buy the Modern Dictionary of Electronics new or used via the Internet.

Graf, Rudolf F. Modern Dictionary of Electronics. Newnes, 1999.

The Random House Dictionary of the English Language, Unabridged, 2nd Edition

You need a big, comprehensive dictionary. Get this one. Despite being a big dictionary, The Random House has great definitions, quick to grasp.

Although out of print, as of 2020 you could still buy a great used copy online for $30 including shipping or possibly for much less. Two versions are available of the 2nd Edition, Unabridged:

I have no idea what the difference is for the deluxe edition, but there seem to be fewer copies of it available in 2020 than the regular edition. I'm sure they both have the same set of definitions. My copy has both ISBNs listed in the front matter, and it is the regular edition.

Flexner, Stuart Berg, and Leonore Crary Hauck, editors. The Random House Dictionary of the English Language. Unabridged, 2nd Edition, Random House, 1987.