Some components can generate considerable heat. Just think of voltage regulators, the beefier types of CPU and microcontroller, MOSFETs carrying a lot of current, but also devices like power LEDs. To get rid of the heat, heatsinks and large copper surface areas are generally employed. Sadly that's not always feasible and sometimes a copper area is insufficient to adequately dissipate the generated heat. Particularly with components in SMD packages that's often the case. In those situations (but also for those occasions where a very robust PCB is required, for example in the automotive sector) the IMS pool from Eurocircuits offers a solution for prototypes and small production quantities.

IMS means Insulated Metal Substrate. The base material consists of 1.5 mm thick aluminum. On top of this comes an electrically insulating layer with a thickness of 100 µm, supporting the copper traces. After that
IMS pool-PCB in de PCB Visualizer
come the solder mask and silk screen (component overlay). Because of this construction technology it is not possible to manufacture PCBs having more than one copper layer. The through-hole plating of, for example, a via would directly lead to a connection to the aluminum base plate which would result in short-circuits, unless ALL the vias are connected to the same net, in which case it would have been absurd to design a double-sided PCB in the first place. Incidentally, the IMS pool construction only allows for single-sided PCBs because of cost reasons. Double-sided circuit boards with an aluminum core are possible, but require a completely different and more expensive production method. Eurocircuits do not offer this.

The material used for the IMS pool is Polytherm, manufactured by MSC Polymer AG. You can find the exact specifications in this datasheet.

The maximum dimensions of the circuit board may be up to 580 × 425 mm, the minimum is 5 × 5 mm. The minimum spacing between individual copper traces is 0.15 mm and the minimum distance from the edge needs is specified as 0.25 mm (0.45 mm when the circuit board is part of a panel and the individual boards are separated using a V-cut). The exact circuit board specifications are in a conveniently arranged list found here.