IMS (Isolated Metal Substrate) also known as MCPCB (metal core PCBs) are PCBs, where the substrate is in metal. The material used is often aluminium or at times copper. A prepreg layer isolates the conductive material from the copper traces. The main advantage of IMS boards compared to more conventional ones in FR4 is to drain more heat, the energy generated by some components. With the recent developments of power LEDs, the demand for MCPCB has exploded.
Most applications call for single sided IMS, but it is also possible to manufacture double side MCPCBs. More over, some suppliers are now moving into multilayers IMS boards. Same as for traditional FR4 boards, for MCPCB, we can choose the material thickness, the copper thickness, etc. But the most important factor is probably its capacity to dissipate heat. This thermo-conductivity is expressed in W/m.K. The standard aluminium board has a value of 1.0 W/m.K, but other options are possible with values of 2.0, 3.0 even 5.0 W/m.K.
Most customers requiring IMS boards select a white or a black solder mask. This is probably related to the fact that we want to either absorb or reflect the LEDs light. But from a pure technical point of view, it is perfectly OK to apply green, red or any other solder mask colour.
The situation is similar for surface finish. The vast majority of the MCPCB use HASL LF. And if there are no fine pitch components, BGAs, then HASL LF is probably the most suitable finish for power LED assembly. Yet, nothing would stop us to propose also all other surface finish; OSP, ENIG, Chem Tin or Silver for your IMS applications.
By working with us, you benefit of our know-how, our highly qualified team and our quick turn around production facility. We presently manufacture IMS on copper and aluminium base, single and double side. Besides common substrates, we are also able to source more advanced material for more options in terms of thickness and thermal performances. At the present moment, we are not able to offer MCPCB on line, but we would be more then happy to quote any projects you might have. Feel free to contact us.