Abstract: Embodiments of this application provide a rear cover of an electronic device, an electronic device, and an air tightness detection system of an electronic device. The electronic device may include a mobile or fixed terminal having waterproof performance such as a mobile phone, a tablet computer, or a notebook computer. The rear cover includes a body portion and a structure layer fixed to a rear surface of the body portion. A smooth detection plane is formed on a rear surface of the structure layer, and a rear end of a balance channel of the rear cover is located within the detection plane, thereby resolving the problem that the material of the rear cover affects air tightness detection on the electronic device.

Abstract: An electronic device may include a mobile phone, a tablet computer, a handheld computer, a walkie-talkie, a POS machine, an event data recorder, a wearable device, a virtual reality device, or in-vehicle original equipment or another terminal product with a loudspeaker. An inner wall of a mounting cavity for mounting a loudspeaker and the loudspeaker are respectively provided with mating surfaces that adapt to each other. In the two mating surfaces, one is provided with a flexible sealing member and a limiting structure, and the other is provided with a rigid sealing member. When the loudspeaker is mounted, the rigid sealing member can move relative to the flexible sealing member along a first direction, until the rigid sealing member is mated with the flexible sealing member. The limiting structure can restrict the flexible sealing member from moving.

Abstract: This application provides an electronic device, including a first cover, a first shell, and a second shell. The first cover includes a first side portion, a middle portion, and a second side portion. The middle portion is connected between the first side portion and the second side portion. The first side portion and the second side portion are spaced apart from and opposite to each other to form an opening. The first side portion, the middle portion, and the second side portion are enclosed to form an accommodating cavity. The first shell and the second shell are both mounted in the accommodating cavity. The first shell and the second shell are matched to support the first cover. The solution of this application can resolve the problem of difficulty in assembling the shells with an exterior part.