2 Layer Flexible Printed Circuit PCB (FPC) Built on Polyimide for
the application of PLC Control
(Flexible printed circuits are custom-made products, the picture
and parameters shown are just for reference)
General description
This is a type of 2 Layer flexible printed circuit (FPC) built on
polyimide for the application of PLC Control.
Basic specifications
Base material: Polyimide 25μm
Layer count: 2 layers
Type: Individual FPC
Format: 73mm x 58mm = 1 type = 1 piece
Surface finish: Immersion gold
Copper weight: Outer layer 35 μm/ Inner layer 0 μm
Solder mask / Legend: Yellow coverlay / white
Final PCB height: 0.20 mm
Standard: IPC 6012 Class 2
Packing: 100 pieces are packed for shipment.
Lead time: 10 working days
Shelf life: 6 months
Features and benefits
Low cost;
Continuity of processing;
Excellent flexibility;
Hassle-free, one-to-one after-sales service;
Free-of-charge PCB panelization;
Prototype PCB capability;
Volume Production capability;
Applications
FFC for industrial control equipment, Tablet computer battery soft
board, automobile GPS navigation flex board, consumer card reader
soft board, Thin-film switch, medical keypad soft board
Specifications of standard coverlay
| Halogen-free flame-resistant type polyimide film based Coverly
(SF305C) |
| Specifications | Polyimide Film Thickness (µm) | Adhesive Thickness (µm) | Applications |
|
| SF305C 0205 | 5 | 5 | Ultrathin FPC |
| SF305C 0305 | 7.5 | 5 |
| SF305C 0309 | 7.5 | 9 |
| SF305C 0515 | 12.5 | 15 | General type |
| SF305C 0520 | 12.5 | 20 |
| SF305C 0525 | 12.5 | 25 |
| SF305C 1025 | 25 | 25 |
| SF305C 1030 | 25 | 30 |
| SF305C 1035 | 25 | 35 | Power batter |
| SF305C 1050 | 25 | 50 |
| SF305C 2050 | 50 | 50 |
Structure of FPC
According to the number of layers of conductive copper foil, FPC
can be divided into single layer circuit, double layer circuit,
multi-layer circuit, double sided and so on.
Single-layer structure: the flexible circuit of this structure is the simplest structure
of the flexible PCB. Usually the base material (dielectric
substrates) + transparent rubber(adhesive) + copper foil is a set
of purchased raw materials(semi-manufactures), the protective film
and transparent glue are another kind of bought raw material.
First, copper foil must be etched to obtain the required circuit,
and the protective film should be drilled to reveal the
corresponding pad. After cleaning, the two are combined by rolling.
Then the exposed part of the pad electroplated gold or tin to
protect. In this way, the big panel board will be ready. Generally
also it’s stamped into the corresponding shape of the small circuit
board. There is also no protective film directly on the copper
foil, but printed resistance soldering coating, so that the cost
will be lower, but the mechanical strength of the circuit board
will become worse. Unless the strength requirement is not high and
the price needs to be as low as possible, it is best to apply the
protective film method.
Double layer structure: when the circuit is too complex to be wired, or copper foil is
needed to shield the ground, it is necessary to choose a double
layer or even a multilayer. The most typical difference between a
multilayer and a single plate is the addition of a perforated
structure to connect the layers of copper foil. The first process
of transparent rubber + base material + copper foil is to make
holes. Drill holes in the base material and copper foil first,
clean and then plated with a certain thickness of copper. The
subsequent fabrication process is almost the same as the
single-layer circuit.
Double sided structure: both sides of the double sided FPC have pads, mainly used to
connect other circuit boards. Although it and monolayer structure
is similar, but the manufacturing process is very different. Its
raw material is copper foil, protective film and transparent glue.
The protective film should be drilled according to the position of
the pad first, then the copper foil should be affixed, the pad and
track lines should be etched and then the protective film of
another drilled hole should be affixed.
