Multilayer
Flexible Printed Circuit (FPC) Multi-layer Flexible PCB Board
(FPC’s
are custom-made products, the picture and parameters shown are just for
reference)
General
description:
The base laminate is
from Shengyi. Coated by yellow covering layer, immersion gold is plated on
pads. A connector is designed at both ends. It’s fabricated per IPC 6012 Class
2 using supplied Gerber data.
Parameter
and data sheet:
|
Size of
Flexible PCB
|
300.5X 25.5mm
|
|
Number of Layers
|
4
|
|
Board Type
|
Flexible circuits
|
|
Board Thickness
|
0.30mm
|
|
Board Material
|
Polyimide
(PI) 25µm
|
|
Board Material Supplier
|
Shengyi
|
|
Tg Value of Board Material
|
60℃
|
|
|
|
PTH Cu thickness
|
≥20 µm
|
|
Inner Iayer Cu thicknes
|
35
µm
|
|
Surface Cu thickness
|
35 µm
|
|
|
|
Coverlay Colour
|
Yellow
|
|
Number of Coverlay
|
2
|
|
Thickness of Coverlay
|
25
µm
|
|
Stiffener Material
|
NO
|
|
Stiffener Thickness
|
N/A
|
|
|
|
Type of Silkscreen Ink
|
NO
|
|
Supplier of Silkscreen
|
N/A
|
|
Color of Silkscreen
|
N/A
|
|
Number of Silkscreen
|
N/A
|
|
|
|
Peeling test of Coverlay
|
No
peelable
|
|
Legend Adhesion
|
3M 90℃No
peeling after Min. 3 times test
|
|
|
|
Surface Finish
|
Immersion
Gold
|
|
Thickness of Nickle/Gold
|
Au:
0.03µm(Min.); Ni 2-4µm
|
|
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
|
Features
and benefits:
Excellent
flexibility
Reducing
the volume
Weight
reduction
Consistency
of assembly
Increased
reliability
Material
optionality
Low cost
Continuity
of processing
Diversified
shipping method
Engineering
design prevents problems from occurring in pre production.
Applications:
Laser
head FPC, medical equipment controller, Tablet antenna soft board
Multilayer
Flexible Circuits:
For the
most part, manufacture of multilayer flexible circuits is based upon processes
of single sided flexible PCB and double sided PTH flexible PCB. Both types
evolve from the conventional covercoated double-sided flexible circuits that
are bonded together. For a number of reasons, it is not recommended to combine
too many flexible circuits into a multilayer flexible circuit.
Materials
and Thicknesses of Multilayer FPC
It
is common practice to use the materials listed below.
Dielectric
Substrates
50
µm (2 mil) polyimide because of its higher stability and easier handling
compared with 25 µm (1 mil) polyimide.
Copper
Foil
35
µm (1 oz.) copper foil, provided this thickness is compatible with the current
carrying requirements of the finished circuit.
Covercoat
25
µm (1 mil) polyimide for a 35 µm (1.4 mil) thick copper foil, since it ensures
a better encapsulation of the conductors than a 50 µm (2 mil) polyimide.
25
µm (1 mil) acrylic adhesive for achieving a good encapsulation and a low-flow
lamination. Too much acrylic adhesive leads to reliability problems, e.g.
barrel cracks, foil cracks, and a too deep etchback.
Outer
Layers
Outer
layers should not be provided with any circuitry (conductors) on the bonding
side because of the risk of air entrapment at the interface.
Bonding
Materials
When
using covercoated flexible circuits as inner layers, the circuits and the rigid
parts are bonded together by means of sheet adhesives.
Processes:
A
simplified flow diagram is shown below.
More
Displays of Multi-layer FPC:
BICHENG PCB WORKSHOP:
BICHENG PCB CERTIFICATE:
BICHENG MAIN COURIERS:
