We are using mixed technology in our PCBA. Would like to know whether there is any criteria governing/guiding the use of mixed technology in such aspects as: 1. Some SMDs cannot be used in some kind of PCB materials such as FR1? 2. Some SMDs are not suitable for some soldering process such as ceramic capacitors not suitable for wavesoldering? 3. Is it advantageous to group SMDs into a single daughter board which is inserted onto the top side of the main board rather than putting all SMDs on the bottom side of the main board?
Any inputs regarding these or those related to mixed technology are highly appreciated.