An arrangement of modular supporting structure or subassemblies constituted of interconnected circuit boards, especially for the assembly of a complex processing circuit in articles of ammunition possessing a search fuze or in airborne target-tracking bodies. The structures or modular subassemblies of the type considered herein consist of circuit boards arranged in a succession, in which between respectively two adjacent circuit boards, there are formed a series of optronic intersecting connections between coupling elements, wherein in the operational positioning of the circuit boards, a transmitting diode and a receiving detector are arranged opposite each other, which are connected with a multiplexer or, respectively, a demultiplexer.