US Patent 7369399 Modular electronic control unit housing

A housing module 10 for a circuit board comprises a first chamber 20 for accommodating a main part of the circuit board and a second chamber 22 bordering the first chamber 20 and having a greater depth that the first chamber 20 to enable it to accommodate a connector 16 located along an edge of the circuit board and protruding above the surface of the circuit by an amount exceeding the depth of the first chamber 20. The exterior of the module 10 is shaped to enable two similar modules 10 to be stacked with the first chambers 20 overlying one another and with the second chambers 22 circumferentially staggered around the stack, thereby and acting to maintain the modules of the stack in alignment with one another.