2-Layer Flex Printed Circuit Board (FPCB) Built on Polyimide for Microstrip Antenna
(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 Microstrip Antenna.
Basic specifications
Base material: Polyimide 25μm + 0.3mm stiffener of stainless steel
Layer count: 2 layers
Type: Individual FPC
Format: 205mm x 74mm = 1 type = 1 piece
Surface finish: Immersion gold
Copper weight: Outer layer 70 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
The end can be whole soldered;
Continuity of processing;
Low cost;
Delivery on time higher than 98% on-time-delivery rate;
Comprehensive equipment management and maintenance and process
control;
RoHS materials;
Eligible products rate of first production: >95%
Diversified shipping method: FedEx, DHL, TNT, EMS
Applications
Keypad FPC, mobile phone module flex board, mobile phone module
flex board Toy lamp strip, industrial surveying and mapping
instrument, Consumer electrostatic Bracelet soft board.
General Properties of 2 Layer FCCL
| Double side adhesiveless flexible copper clad laminate (SF202) |
| Test Item | Treatment Condition | Unit | Property Date |
| IPC Standard * value | Typical Value |
| SF202 0512DT | SF202 1012DT |
| Peel Strength (90º) | A | N/mm | ≥0.525 | 1.2 | 1.4 |
| 288℃, 5s | ≥0.525 | 1.2 | 1.4 |
| Folding Endurance (MIT) | R0.8 X 4.9N | Times | - | ＞80 | ＞50 |
| Thermal Stress | 288℃, 20s | - | - | No delamination | No delamination |
| Dimensional Stability | MD | E-0.5/150 | % | ±0.2 | ±0.05 | ±0.05 |
| TD | ±0.05 | ±0.05 |
| Chemical Resistance | After Chemical Exposure | % | ≥80 | ＞85 | ＞85 |
| Dielectric Constant (1MHz) | C-24/23/50 | - | ≤4.0 | 3.2 | 3.3 |
| Dissipation Factor (1MHz) | C-24/23/50 | - | ≤0.01 | 0.007 | 0.008 |
| Volume Resistvitiy | C-96/35/90 | MΩ-cm | ≥10^6 | 4.5 x 10^8 | 3.5 x 10^8 |
| Surface Resistance | C-96/35/90 | MΩ | ≥10^5 | 1.5 x 10^6 | 2.0 x 10^6 |
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.
