Storm Circuit has been producing Multilayer PCBs for over 10years. Over the years, we have seen all types of multilayer constructions from various industries, answered all types of multilayer questions, and solved all types of problems with multilayer PCBs.
Multilayer PCB is a circuit board with two or more layers. The material unlike Double-Sided PCBs with only two conductive layers all multilayer PCBs is that it must have at least three layers of conductive material, and the PCB boards are buried in the center of the material.
Benefits of Multilayer PCBs (compared to single or double-sided PCBs) Multilayer PCB Multilayer PCB,Multilayer Bga Board,Multilayer Smd PCB,Multilayer Circuit Board PCB Storm Circuit Technology Ltd , http://www.stormpcb.com
According to regulations, the energy efficiency of mercury lamps must be at least 30 lm/w, the energy efficiency of high-pressure sodium lamps must be at least 50 lm/w, and the energy efficiency of LED lamps must reach at least 50 lm/w before June 30, 2012, from 2012. Must be at least 60 lm/w from the 1st of the month.
The document also stipulates that the ordinary tungsten filament incandescent lamp requires a lighting time of not less than 1000 hours, a halogen lamp of not less than 2000 hours, and a non-directional light LED lamp having a longest life of 25,000 hours.
In addition, the document also requires mercury and lead content for different power fluorescent lamps, but the new rules do not cover directional illumination lamps and lamps with a luminous flux of less than 150 lumens. 
Higher assembly density
Smaller size (considerable savings on space)
Increased flexibility
Easier incorporation controlled impedance features.
EMI shielding through careful placement of power and ground layers.
Reduces the need for interconnection wiring harnesses (reduces overall weight
The Russian government requires that LED lamps for lighting must have an energy efficiency of at least 50 lm/w.
[High-tech LED News] According to foreign media reports, the Russian Federation government issued an order on July 20, 2011 to approve the requirements for lighting equipment and lighting lamps used in AC circuits.