Aluminum is the most popular material in high thermal conductivity boards.
Normal thermal is from 0.8-2.00 W/m.k,and higher can up to 8.0 W/m.k.
Here is an example of Yamaha power board,this is double sided board with metal core. The Aluminum is in the middle,and copper layer on top and bottom side.From top side,we can see there are TO-252 footprint parts,these components have very high heat when working. so high thermal conductivity board is required .The design is very great as there are many thermal vias at each TO-252 parts.The heat will go through another side soon .
Do you know what is ENEPIG in PCB?
What is ENEPIG?ENEPIG-Electroless Nickel Electroless Palladium Immersion Gold is a surface finish for Printed Circuit Boards.ENEPIG works well with lead free and conventional eutectic solder alloys.This is the best way for gold wire bonding. Advantages for ENEPIG:
1.[Black Nickel" free – no possibility of grain boundary corrosion of nickel surface by immersion gold
2.Palladium acts as an additional barrier layer to further reduce copper diffusion to surface, thus ensuring good solderability
3.Palladium completely dissolves into solder, without leaving an excessively high P% rich interface, exposing an oxide-free nickel surface allowing reliable formation of Ni/Sn intermetallic
5.Withstands multiple lead-free reflow soldering cycles
6.Demonstrates excellent gold wire bondability
7.Process costs substantially lower than electrolytic nickel gold or electroless nickel electroless gold
ENEPIG PCB,Aluminum PCB,Rigid PCB,Flexible PCB
Storm Circuit Technology Ltd , http://www.stormpcb.com