Rigid PCB will include from Single Layer, Double Layer to Multilayer PCB, within each of these PCB can be separate into different category according to their laminate and application, like Aluminum backed PCB:
Aluminum backed PCB have many benefits over conventional PCBs such as

1 Dissipation of heat without using additional heat-sink;
2 Mechanically rigid increasing the physical strength of the assembly;
3 Reduces the effect of thermal stress on all components, increasing life and durability;
4 Improved thermal conduction leading to versatility in component and tracking layout enabling PCB dimensions to be reduced;
5 Reduce component operating temperatures, improving reliability;
6 Substrate Aluminum can be drilled / machined and routed, aiding PCB mounting.

As well as HDI(High Density Interconnect) PCB include Blind & Buried vias, our HDI capabilities include laser microvias, blind and buried vias, fine lines and spaces, sequential lamination, via-in-pad technology. We have provided microelectronic pcbs with fine pitch devices down to 200 microns, using 50 micron laser drilled via-in-pad technology and thin build-up materials. 

Below you can find the Rigid PCB we have ever made for our valuable customers: