Carrier cards and carrier boards, also referred to as “baseboards”, implement application specific functionality, I/O interfaces, peripherals and power supplies for computing applications. They form part of a multi card/board system, providing a mounting option for one or more system-on-module (SOM) or computer-on-module (COM) devices. Baseboards are available in a number of form factors including: single board carriers designed to operate stand-alone with a SOM, stackable systems for embedded computing and rack mounted cards for large systems.

SOM and COM cards are either plugged into the baseboard via a standard physical and electrical connection arrangement or soldered directly on as a “stamp”[C1] . There are a large variety of baseboards available optimized for specific applications. These include: simple low cost carrier boards with customizable through-hole sections[C2]  for prototyping, carrier boards with standard peripheral connection sockets like PCI express and high performance carrier cards for rack systems that comply with standards like compact PCI.

There are several advantages to a multi board architecture. Products can be rapidly designed on existing hardware that is known to work in convenient form factors. An example of this is PC/104 family of boards that offer rugged physical stacking capability. A SOM may contain high-density componentry that requires more expensive PCB and manufacturing technology than the elements on a baseboard – lowering overall system cost. By separating the SOM from the baseboard with a standard interface, the SOM can be upgraded without redesign of the baseboard. A major advantage is that a SOM manufacturer is application agnostic - volumes are associated with many products and many markets. This allows for economies of scale to operate on high cost element of the system BOM.