PCB Layout Services,
Quick Turn PCB,
Prototype PCB: Skyyear has been
in Asia Prototype PCB, Printed Circuit Board, Antenna, PCBA (Assembly PCB) /
SMT, TFT Monitor, Touch Screen Monitor, Connector and in Sharkfin Antenna
solution. Skyyear intends to provide the very best customer solution to meet
your highest requirements in Asia PCB, PCBA (Assembly PCB) / SMT, TFT
Monitor and Antenna Arena. We have offices in around the globe and namely in
Asia such as China, Taiwan, Malaysia and in the America. Skyyear Asia was
established from backbone of connector and switches companies, our investors
consists of expertise from connector, switches, PCB and antenna experts and
one of the key success of our product is that we have patented GPS, AM and
FM signal receiving into one single unit PCB board (Assembly PCB) under one
sharkfin antenna solution, it has been successfully patented in United State
and multiple countries in Asia.
We have more than 10 years of PCB Layout Services, Quick Turn
PCB, Prototype PCB & Antenna supply chain experience in Asia PCB
arena. Our SMT lines are state of the art latest and fastest placement
machines to provide the best and quick solution for our valuable customers.
IF you are looking at Asia PCB / PCBA (Assembly PCB) SMT / TFT Monitor /
Touch Screen Monitor/ Connector / Antenna solution, we will provide you the
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Turn PCB & PCB Layout Service"
What Are Multi-Layers?
Multi-layer PCBs are circuit boards made up of
more than two electrical layers (copper layers) superimposed on each other. The
copper layers are bonded together by resin layers (prepreg). Multi-layer boards
represent the most complex type of printed circuit boards. Their cost is
relatively high, owing to the complexity of the manufacturing process, lower
production yields and difficulty of re-working on them. The need for multi-layer
boards has been necessitated by the increasing packaging density of integrated
circuits, which give rise to high concentration of interconnecting lines.
The printed circuit layout results in
unpredictable design problems like noise, stray capacitance, cross-talk etc. The
PCB design, therefore, must aim at minimizing the length of the signal lines and
avoiding parallel routing etc. Obviously, such type of requirements could not be
met satisfactory in single-sided and even double-sided printed circuit boards
due to limited cross-over which could be realized. Thus, to achieve
satisfactorily performance from the circuit in the presence of a very large
number of interconnections and cross-over, the PCB must be extended beyond
two-plane approach.
This gives rise to the concept of multi-layer
circuit boards. Hence, the primary intent of fabricating a multi-layer printed
circuit board is to provide one more degree of freedom in the selection of
suitable routing paths for complex and/or noise-sensitive electronic circuits.
Multi-layer boards have at least three layers of conductors, in which two layers
are on the outside surface while the remaining one is incorporated into the
insulating boards. The electrical connector is commonly completed through plated
through-holes, which are transverse to the boards. Unless otherwise specified,
multi-layer PCBs are assumed to be plated through hole as with double-sided
boards.
Multi-layer boards are fabricated by stacking two
or more circuits on top of each other and establishing a reliable set of
pre-determined interconnections between them. The technique begins with a
departure from conventional processing in that all the layers are drilled and
plated before they are laminated together. The two innermost layers will
comprise conventional two-sided PCB while the various outer layers will be
fabricated as separate single-sided PCBs.
Prior to lamination, the inner layer boards will
be drilled, plated through, imaged, developed and etched. The drilled outer
layers, which are signal layers, are plated through in such a way that uniform
donuts of copper are formed on the underside rims of the through-holes. This is
followed by lamination of the various layers into a composite multi-layer with
wave-solderable interconnections. The lamination may be performed in a hydraulic
press or in an over-pressure chamber (autoclave). In the case of hydraulic
press, the prepared material (press stack) is placed in the cold or pre-heated
press (170 to 180 °C for material with a high glass transition point). The glass
transition temperature is the temperature at which the amorphous polymers
(resins) or the amorphous regions of a partially crystalline polymer change from
a hard and relatively brittle state to a viscous, rubbery state. Multi-layer
boards find applications in professional electronics (computers, military
equipment), particularly whenever weight and volume are the over-riding
considerations.
However, there has to be a trade-off which is
simply the cost for space and weight versus the board's costs. They are also
very useful in high speed circuitry because more than two planes are available
to the PCB designer for running conductors and providing for large ground and
supply areas.