Electronic device assembly and ball joint holder thereof

A ball joint holder adapted to be assembled with a ball joint, wherein the ball joint

• comprises a joint rod and a ball body, and the ball body is connected to one end of the ball joint rod, and wherein the ball joint holder comprises:
• a fixing plate having an assembling surface;
• an assembling member disposed on the assembling surface of the fixing plate;
• and
• a ball joint supporting plate having a pivot side, a swingable side, and a slot, wherein the slot is between the pivot side and the swingable side and is adapted to be inserted by the joint rod, and the pivot side is pivotally connected to the assembling surface of the fixing plate, allowing the ball joint supporting plate to swing relative to the fixing plate between an extended position and a folded position by taking the pivot side as a fulcrum, so that the assembling member is selectively assembled with the ball joint supporting plate.