FPC soft electronic circuit board related terms!

2019-07-23 16:14:29

FPC is a flexible electronic circuit board. The flexible circuit board is made of polyimide or polyester film and is a highly reliable and 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, notebook computers, PDAs, digital cameras, LCM and many other products. The following coatings are used to introduce the commonly used terms of FPC.

1. Access Hole exposes holes 

Often referred to as the protective layer of the soft board Coverlay (the exposed hole must be punched out first), used to fit the surface of the soft board as a solder mask. However, it is necessary to deliberately expose the hole ring wall or square pad required for welding to facilitate the welding of the parts. The so-called "Access Hole" original text means that the surface has a hole to expose, so that the outside world can "close" to the surface of the surface of the surface of the surface of the solder joint. Some multilayer boards also have such exposed holes.

2, Acrylic

It is a common name for polyacrylic resins. Most of the soft boards use their films as a follow-up film.

3. Adhesive

A substance that allows the two interfaces to bond, such as a resin or paint.

4. Anchoring Spurs

On the middle plate or single panel, in order to make the hole ring pad have more strong adhesion on the plate surface, you can add a few finger claws on the extra empty space outside the hole ring to make the hole ring more Consolidate to reduce the possibility of floating off the board.

5, Bandability

A soft board that is a feature of Dynamic Flex Board, such as the print heads of a computer disk drive, should have a "bend test" of one billion times.

6, Bonding Layer

Often referred to as a film layer of a multi-layer board, or a TAB tape, or a board of a soft board, an adhesive layer between the copper skin and a polyimide substrate.

7, Coverlay/Cover Coat

The outer layer of the soft board is not easy to use the green paint used for the hard board because of the possibility of falling off during bending. It is necessary to use a soft "acrylic" laminate on the board surface, which can be used as a solder mask and protect the outer layer, and enhance the resistance and durability of the soft board. The outer film is specifically referred to as a cover or protective layer.

8, Dynamic Flex (FPC)

Refers to a flexible circuit board that needs to be used for continuous motion, such as a soft board in a disk drive read/write head. In addition, "Static FPC" refers to a soft board that no longer has an action after assembly.

9, Film Adhesive

Refers to the dry flaking adhesive layer, which may contain a film of reinforcing fiber cloth, or a thin layer containing no reinforcing material, only the adhesive material, such as the adhesive layer of FPC.

10. Flexible Printed Circuit,

It is a special circuit board that can be used for three-dimensional shape change when assembled downstream. The substrate is flexible polyamine (PI) or polyester (PE). This kind of soft board is also like a hard board, which can be made of plated through holes or surface pads for through hole insertion or surface bonding. The board surface can also be attached with a soft cover layer for protection and soldering protection, or a soft solder mask green paint.

11, Flexural Failure

Due to the repeated bending and flexing action, the material (sheet) is broken or damaged, which is called Flexural Failure.

12, Kapton

This is the trade name of DuPont's product. It is a kind of "polyimide" sheet-like insulating soft material. After attaching rolled copper foil or electroplated copper foil, it can be made into a soft board (FPC) substrate. .

13, Membrane Switch

Using a transparent polyester (Mylar) film as a carrier, silver paste (SilverPastes or silver paste) is printed on a thick film line by a screen printing method, and then combined with a hollowed-out gasket to bond with a convex panel or PCB. Become a "touch" switch or keyboard. Such small "button" devices, commonly used in hand-held calculators, electronic dictionaries, and some home appliance remote controls, are called "membrane switches."

14, Polyester Films

Referred to as PET sheet, the most common is DuPont's product MylarFilms, which is a material with good electrical resistance. In the circuit board industry, the transparent protective layer on the surface of the imaged dry film, and the Coverlay on the surface of the soft board (FPC) are PET film, and it can also be used as the substrate of the silver film circuit (Membrane Circuit). In the electronics industry, it can also be used as a cable, a transformer, an insulating layer of a coil, or a tubular storage device for multiple ICs.

15, Polyimide (PI)

It is an excellent resin which is polymerized by Bismaleimide and Aromaticdiamine. It was first known as the powdery resin product Kerimid 601 from the French company "Rhone-Poulenc". DuPont made it into a sheet called Kapton. This type of PI sheet is excellent in heat resistance and electrical resistance. It is an important raw material for soft board (FPC) and automatic tape winding (TAB). It is also an important sheet for advanced military hardboard and supercomputer motherboards. The translated name of the mainland is "poly-pyrene."

16, Reel to Reel

Some electronic component assemblies can be produced by reeling and reeling processes, such as TAB, IC's Lead Frame, and some soft boards (FPC), which can be retracted by tape. Convenient to complete its online automated work to save time and labor costs for one-piece work.