Abstract: An electronic device includes a metal back cover, a metal frame, and a first, second, third, and fourth radiators. The metal frame includes a discrete part and two connection parts. The connection parts are located by two sides of the discrete part, separated from the discrete part, and connected to the metal back cover. A U-shaped slot is formed between the discrete part and the metal back cover and between the discrete part and the connection parts. The first radiator is separated from the discrete part and includes a feed end. The second, third, and fourth radiators are connected to the discrete part and the metal back cover. The third radiator is located between the first and second radiators. The first radiator is located between the third and fourth radiators. The discrete part and the first, second, third, and fourth radiators form an antenna module together.

Abstract: A cleaning device. The cleaning device, for cleaning a brush of a wafer scrubber, includes a cup and a dummy pad. The dummy pad is disposed in the cup. The brush rubs against the dummy pad. A method of cleaning a brush of a wafer scrubber, comprising providing a cup with a dummy pad disposed in the cup, and rubbing the brush against the dummy pad.