Off the topic of metal core boards and onto rigid and flex boards:

The IPC releases some information on the PCB industry for April 2011 compared to April 2010:

- Rigid PCB shipments are up just 0.8% (for the YTD, up ~5%)
- Flex PCB shipments are up a whopping 7.2%

This data just goes to show the huge increases in use for high technology boards over standard (soon to be called old technology) boards. Flex boards, rigid flex and metal core boards are becoming more and more commonplace in applications.

Source: IPC        LT Circuit Co.,Ltd