Currently, many modern Dual SIM phones suffer hybrid or mixed slot limitation . This slot, where the second SIM is housed, can also accommodate a memory card. This means that if two SIMs are inserted in the device, the possibility of inserting a micro SD card is lost. If a micro SD is preferred, a second SIM can no longer be inserted.
How to Put Micro SD and SIM card in one body
There is the possibility to use both SIM and micro SD at the same time in a modern Dual SIM phone. This is a manual modification that consists of joining the second SIM and micro SD on a single chip that is properly housed in the hybrid slot. In this way, the phone will read the second SIM and micro SD at the same time .
The method has been successfully tested on a Xiaomi Redmi Note 4 Dual SIM . It is not guaranteed to work on other models. There is a risk of damaging the SIM and the micro SD involved. If proper work is not done, forcing insertion into the device could damage it as well. And if you do a good physical work, there is a possibility that the phone is not able to read the second SIM and micro SD at the same time . You can try it on your device at your own risk. The essential requirement is that your phone is Dual SIM with hybrid slot.
The video below, illustrates the process quite well. It all boils down to pasting the second SIM over the micro SD . Previously the SIM must have been removed from the surrounding plastic . In addition, the micro SD must be polished enough that, together with the SIM, the thickness is adequate and there is no problem inserting into the cell phone.