Why use BTB Connectors? There are at least ten design, production, and marketing situations where using two or more interconnected pc boards rather than a single one makes sense:
Where form factor constraints limit the overall size of a single, larger board approach, and a three-dimensional arrangement is needed to take advantage of available package depth.
Where it is unacceptable to place low-level, highly sensitive analog I/O or RF circuits near high-speed, noisy digital circuits.
Where high voltages are present, and good engineering practice as well as regulatory standards mandate separation.
Where thermal concerns require placing hotter components in a separate location for improved dissipation and thermal management.
Where a given circuit subsection may be used or reused across multiple versions of a product, such as a core processing board which is paired with basic multiline user display and pushbuttons, as well as with a more sophisticated graphic touchscreen for different models of an alarm or sensor system.
Where production requires special components, such as power devices and heatsinks that call for a special manufacturing/assembly process or manual insertion, while the rest can use automated insertion and soldering.
Where the vendor expects to upgrade one function in a system, such as the processor and memory, but wants to leave the analog function unchanged for technical confidence and cost amortization.
Where field experience indicates that one part of the system, such as outward-facing I/O, is more likely to need field replacement, while internal core functions such as processor and memory will have a longer mean time to failure (MTTF).
Where some components need thicker PC board material and heavier copper cladding, such as for power components.
Where EMI/RFI considerations and concerns mandate separation between functions, and perhaps even RF shielding of part of the circuitry.
It`s clear that there are many legitimate design, production, and support reasons for choosing or insisting on using multiple pc boards. Among the applications for which this occurs are industrial control systems, motor controls, programmable logic controllers (PLCs), alarm and security units, medical systems such as portable X-ray or ultrasound machines, and devices with different human-machine interfaces (HMI) .
