FPC is a flexible electronic circuit board, a flexible circuit board made of polyimide or polyester film as a substrate with high reliability, excellent flexible printed circuit board. Referred to as soft board or FPC, it has the characteristics of high wiring density, light weight and thin thickness.
FPC is mainly used in mobile phones, laptops, PDAs, digital cameras, LCM and many other products, the following is to introduce FPC commonly used related terms.
1. Access Hole (access hole, bottom hole)
Often refers to the protective layer Coverlay on the exterior of the flexible board (to be first punched out of the exposure hole), used to fit on the surface of the flexible board circuit as a welding film. However, it is necessary to deliberately expose the hole wall or square welding pad required for welding in order to facilitate the welding of parts. The so-called "Access Hole" original text refers to the surface with a exposure hole, so that the outside world can "get close" to the solder joint under the surface protection layer. Some multilayer panels also have such outcropping holes.
It is the common name of polyacrylic resin, and most soft boards use its film as a subsequent film.
3. Adhesive adhesive or adhesive
A substance, such as a resin or paint, that binds two interfaces together.
4, Anchoring Spurs claw
On the middle plate or single panel, in order to make the hole ring welding pad have a stronger adhesion property on the surface of the plate, a few fingers can be added to the excess open space outside the hole ring to make the hole ring more consolidated to reduce the possibility of floating away from the surface of the plate. As the attached figure is the soft board "surface protection layer" under the faintly visible claw diagram.
5, Bandability, bending ability
As one of the characteristics of a Dynamic Flex Board, such as the Print Heads of a computer disk drive, the quality of the flexible board should reach a billion "bending tests".
Bonding Layer Bonding layer followed by bonding layer
Often refers to the film layer of a multilayer board, or TAB tape, or a sheet of flexible board, the copper coating and polyimide (PI) substrate between the adhesive layer.
7, Coverlay/Cover Coat
The outer circuit of the soft board is not easy to use the green paint used in the hard board, because it may fall off when bending. It is necessary to use a soft "acrylic" laminate on the surface of the board, which can be used as a welding film and protect the outer line, and enhance the resistance and durability of the soft board, this special "outer film" is called the surface protector or protective layer.
8, Dynamic Flex(FPC) dynamic soft board
It is a flexible circuit board that needs to be used for continuous motion, such as the soft board in the read/write head of a disk drive. In addition, "Static FPC" refers to a type of flexible board that no longer acts after being properly assembled.
9. Film Adhesive film followed by adhesive film
Refers to a dry laminate follow-up layer, which may contain a reinforced fiber cloth film, or a thin layer without reinforcing material and only a follow-up material, such as the follow-up layer of FPC.
10, Flexible Printed Circuit,FPC soft board
Is a special circuit board, in the downstream assembly can do three dimensional shape changes, the substrate is flexible polyimide (PI) or polyester (PE). The soft plate is also like the hard plate, and can be made of plated through holes or surface adhesive pads for through holes insertion or surface adhesive installation. The surface of the board can also be attached to a soft protective and solderproof Cover Layer, or a soft solderproof green paint can be printed.
11. Flexural Failure
The fracture or damage of the material (sheet) caused by repeated bending and Flexural Failure is called flexural failure.
12, Kapton polyimide soft material
This DuPont product is a "polyimide" sheet of soft insulating material, which can be made into a soft board (FPC) base material when attached to rolled or electroplated copper foil.
13 Membrane Switch
With the use of transparent polyester (Mylar) film as the carrier, silver glue (SilverPastes or silver paste) is printed on the thick film line, and then combined with the hollowing gasket, and the protruding panel or PCB, to become a "touch" switch or keyboard. This small "key" device is often used in hand-held calculators, electronic dictionaries, and some home appliance remote controls, which are called "film switches".
14. Polyester Films
PET flakes, most commonly known as DuPont's MylarFilms, are a material with good electrical resistance. In the circuit board industry, the transparent protective layer on the surface of the imaging dry film and the Coverlay on the surface of the soft board (FPC) are all PET films, and the membrane itself can also be used as the base material of the silver paste printed film line (MPIT). Other in the electronics industry can also be used as cable, transformer, coil insulation or multiple IC tubular storage device.
15. Polyimide (PI)
It is an excellent resin that is polymerized by Bismaleimide and Aromaticdiamine, and is first known for the powder resin product Kerimid 601 launched by the French "Rhone-Poulenc" company. Dupont made it into sheets and called it Kapton. The heat resistance and electrical resistance of this PI plate are very superior, is an important raw material of soft board (FPC) and automatic binding of tape (TAB), and is also an important plate of advanced military hard board and supercomputer host board, this material is translated as "polyamide" in mainland China.
16, Reel to Reel reel wheel (disc) continuous operation
Some electronic parts components can be produced by retractable reel (disc) retractable process, such as TAB, IC metal leg (Lead Frame), some soft board (FPC), etc., can use the convenience of retractable tape to complete its online automatic operation, in order to save the time and labor cost of single-piece operation.