Double Sided Assembled Flexible Printed Circuit Built On Polyimide With 90 OHM Impedance Control for Automobile Sensors
(Flexible printed circuits are custom-made products, the picture
and parameters shown are just for reference)
General description
This is a type of flexible printed circuits built on polyimide
substrate with connectors assembled for the application of USB
wireless. The base material is double layer adhesive RA Copper 35um
on polyimide 25um thick. It has 90 Ohm differential impedance with
4.7mil track and 7.9mil track seperation. There're 2 thickness on
the head stiffener, one for 0.3mm FR-4 and one for 0.8mm FR-4 to
support the connectors. Whole flex has no silkscreen, but with
yellow coverlay and immersion gold on pads. The base material is
from Shengyi SF202, entire board supplying single up. They're
fabricated per IPC 6012 Class 2 using supplied Gerber data. Every
80 pieces are packed for shipment.
Parameter and data sheet
PCB Size: | 120 x 95mm = 1 PCS |
Number of Layers | 2 layers |
Board Type | Flexbile cirucit |
Board Thickness | 0.2mm +/-10% |
Board Material | Double layer adhesive RA Copper 35um, Polyimide 25um |
Board Material Supplier | Shengyi |
Tg Value of Board Material | 60℃ |
|
PTH Cu thickness | 20 um |
Inner Iayer Cu thicknes | N/A |
Surface Cu thickness | 35 um (1oz) |
|
Coverlay Colour | Yellow |
Number of Coverlay | 2 |
Thickness of Coverlay | 25 um |
Stiffener | 0.3mm FR4+pure glue 0.8mm FR4+pure glue |
|
Type of Silkscreen Ink | N/A |
Supplier of Silkscreen | N/A |
Color of Silkscreen | N/A |
Number of Silkscreen | N/A |
|
Minimum via (mm) | 0.3 |
Minimum Trace (mil) | 4.7 |
Minimum Gap(mil) | 7.9 |
Impedance Control | 90 Ohm differential impedance with 4.7mil track and 7.9mil strak
seperation |
|
Surface Finish | Immersion Gold |
RoHS Required | Yes |
Famability | 94-V0 |
|
Thermal Shock Test | Pass, -25℃±125℃, 1000 cycles. |
Thermal Stress | Pass, 300±5℃,10 seconds, 3 cycles. No delamination, no blistering. |
Function | 100% Pass electrical test |
Workmanship | Compliance with IPC-A-600H & IPC-6013C Class 2 |
Type of artwork to be supplied | email file, Gerber RS-274-X, PCBDOC etc |
Service area | Worldwide, Globally. |
Features and benefits
Excellent flexibility;
Reducing the volume;
Weight reduction;
High solderability, no stressing of circuit boards and less
contamination of PCB surface;
Quick and on-time delivery;
16000 square meter workshop;
On-time service;
More than 17 years of PCB experience;
Applications
Industrial control temperature controller, Automobile sensor flex
board, LED display, Tablet PC module, laser head FPC, mobile phone
built-in antenna FPC, contact belt of inkjet printer
Components of a flexible circuit
A flexible circuit consists of copper foil, dielectric substrate+
coverlay and adhesive.
Copper foil is available in two different types of copper: ED
Copper and RA copper.
ED copper is an electro-deposited (ED) copper foil produced in the same way
as the copper foil used for rigid printed circuit boards. This also
means that the copper is “treated”, i.e., it has a slightly rough
surface on one side, which ensures a better adhesion when the
copper foil is bonded to the base material.
RA copper is a rolled and annealed copper foil produced from
electrolytically deposited cathode copper, which is melted and cast
into ingots. The ingots are first hot-rolled to a certain size and
milled on all surfaces. The copper is then cold-rolled and
annealed, until the desired thickness is obtained.
Copper foil is available in thickness of 12, 18, 35 and 70 μm.
The most common available for dielectric substrate and coverlay is polyimide films. This material can also be used as
coverlay. Polyimide is best suited for flexible circuits because of
its characteristics as stated below:
High temperature resistance allows soldering operations without
damaging the flexible circuits
Very good electrical properties
Good chemical resistance
Polyimide is available in thicknesses of 12.5, 20, 25 and 50 μm.
Base laminates for rigid printed circuit boards are copper foils
laminated together with the base materials, the adhesive coming from the prepreg material during lamination. Contrary to
this is the flexible circuit where the lamination of the copper
foil to the film material is achieved by means of an adhesive
system. It is necessary to distinguish between two main systems of
adhesive, namely thermoplastic and thermoset adhesives. The choice
is dictated partly by the processing, and partly by the application
of the finished flexible circuit.