Clarifications of FPC
According to the combination of base material and copper foil, flexible circuit board can
Be divided into two types: flexible board with adhesive and flexible board without adhesive.
the price of non-adhesive flexible PCB is much higher than that of adhesive flexible PCB,
but its flexibility, bonding force between copper foil and substrate and flatness of solder
Are also better than that of adhesive flexible PCB. So it is only used in the high demand
Situations, such as the: COF (CHIP ON FLEX, flexible board with bare chip, the high flatness
of the pad) and so on. Because its price is high, most of the flexible PCBs used in the market
Are still adhesive flexible circuit board. Because the flexible circuit board is mainly used in the
Situation where bending is required, if the design or process is not reasonable, it is easy to
Produce micro-cracks, welding and other defects.

Economy of using FPC
If the circuit design is relatively simple, the total volume is small, and the space is suitable,
the traditional internal connection is much cheaper. Flexible circuits are a good design option
If the circuit is complex, processes many signals or has special electrical or mechanical
Requirements. When the size and performance of applications exceed the capacity of rigid
Circuits, flexible assembly is the most economical. A 12mil pad with a 5mil through hole
and a flexible circuit with 3mil lines and spacing can be fabricated on a thin film. Therefore,
It is more reliable to mount the chip directly on the film. There is no flame retardant that could
Be an ion source. these films may be protective and solidified at higher temperatures to obtain
Higher glass transition temperatures. Flexible materials are less costly than rigid materials
Because they are free of connectors.


FPC Case: Double Layer Flexible Circuit Board (FPC)
Built on Polyimide for Medium Access Control
(Flexible printed circuits are custom-made products, the picture and parameters shown
Are just for reference)


General description
this is a type of double sided flexible printed circuit (FPC) built on polyimide for the
Application of Medium Access Control.

Basic specifications
Base material: Polyimide 25m
Layer count: 2 layers
Type: Individual FPC
Format: 156mm x 41mm = 1 type = 1 piece
Surface finish: Immersion gold
Copper weight: Outer layer 35 m/ Inner layer 0 m
Solder mask / Legend: Black coverlay / white
Final PCB height: 0.25 mm (inclusive of stiffener)
Standard: IPC 6012 Class 2
Packing: 100 pieces are packed for shipment. 
Lead time: 10 working days
Shelf life: 6 months

Features and benefits
Reducing the volume;
Weight reduction;
Consistency of assembly;
Experienced sales persons and skilled customer services;
No minimum order quantity and low cost sample;
Focus on low to medium volume production;
on-time service;
More than 15 years of PCB experience;

Application
Industrial control audio equipment, Tablet PC camera soft board, Automobile sensor
Flex board, LED display soft board, Tablet PC module soft board, mobile phone module
Flex board

General Properties of Coverlay

Test Item		Treatment Condition	Unit	Property Date
				IPC Standard * value	Typical Value
					SF305C 0205	SF305C 0309
Resin Flow		A	mm	-	0.15	0.15
Peeling Strength (90)		A	N/mm	0.7	0.82	1.06
		288, 5s		0.53	0.80	1.11
Thermal Stress		288, 20s	-	-	No Delamination	No Delamination
Dimensional Stability	MD	after peeling off the paper	%	0.2	0.1	0.1
	TD				0.1	0.1
Chemical Resistance		after Chemical Exposure	%	80	90	90
Volume Resistvitiy		C-96/35/90	M-cm	10^6	7.8 x 10^6	2.2 x 10^7
Surface Resistance		C-96/35/90	M	10^4	2.5 x 10^5	4.2 x 10^5

Explanations:
C = Humidity conditioning;
E = Temperature conditioning;
1. Testing after laminating with shining side of copper foil in suitable condition;
* Certified to IPC-4203/2 Epoxy adhesive on one or two sides of polyimide dielectirc

Product Code Description
SF305C 05 15
SF305C: Shengyi Coverlay Designation
05: PI Film Thickness, 05- 12.5m; 10-25m
15: Adhesive Thickness, 15-15m, 25- 25m; 35- 35m


FPC

Automatic sticking film machine