For a simple reason : the products are getting smaller. Nowadays, countless electronic devices, such as smartphones, tablets, blood sugar detectors, require stricter sizes and tighter internals, leaving less room for connectors. This trend is also found in the field of national defense and aerospace, such as satellites, guided missiles and Avionics systems, where the compactness requirements can only be met by “miniature” connectors.
Designers should consider the ease of replacement, especially in closed shells. Below are some design recommendations from micro connector vendors. Consider the connector early in the design, understand the limitations of the space, understand the current load capacity, consider the stability of the small/micro connection, consider the easy replacement, understand the functional requirements of the connector, and consider the mechanical stress.