Most PCB manufacturers are finding the demand for multilayer boards
increasing by leaps and bounds. This growing demand is fed by the need
for smaller, lighter boards for use in electrical devices, military
equipment, healthcare miniaturization, and an expanding market for smart
devices incorporated in home automation systems.multilayer pcb advantages
Smartphones and computers are perfect applications for multilayer PCBs
with their need for compactness and light weight, yet sophisticated
functionality.
From a technical standpoint, there are numerous advantages to the use of
multilayer designs, over and above saving space and weight:
By incorporating multiple layers in a single PCB, boards can increase functionality.
Manufacturing processes for multilayer boards result in high-quality, reliable end products.
Multilayer boards by their innate electrical properties provide high capacity and high speed in a smaller footprint.
Higher density of assembly
Connectors required for multiple separate PCBs are reduced or eliminated, simplifying construction and further reducing weight.
Multilayer PCBs can be manufactured in both rigid and flexible
construction. Be advised though, that the more layers incorporated in a
flex PCB, the less flexible it becomes.
Every technology has pros and cons, and multilayer PCBs are not immune from negative attributes:
Cost – one of the primary negatives in designing and implementing
multilayer PCBs is the cost. As specialized processes are involved in
the manufacturing of these boards, there is a considerable investment
required for fabricators to offer these services. This makes the cost of
multilayer boards higher than a traditional single or double-sided
board.
Service availability – not all PCB manufacturers have made the
commitment to manufacturing these complex boards, limiting the resource
options available to PCB designers.
Compactness of multilayer boards generates design concerns for such issues as crosstalk and impedance problems.
With increased functionality comes the need for more extensive testing
of a single PCB. Manufacturing cycles may also be longer, due to the
very complexity of the manufacturing process.
Repairing a multilayer PCB can be extremely difficult, and may even be
unfeasible or impossible. This makes failure of a multilayer board
costly, since it may need to be totally replaced.
Interconnection between layers is critical for board function, making
design and fabrication of microvias and overall density critical.
