Abstract: The application discloses examples of a device housing of an electronic device including a magnesium-alloy substrate. The device housing further including a treatment layer applied over the magnesium-alloy substrate and a metallic coating layer applied over the treatment layer to provide a metallic luster. Further, a paint coating layer is disposed over a first portion of the metallic coating layer. Further, a top coating layer is applied over the paint coating layer and a visible second portion of the metallic coating layer.

Abstract: A cooling device includes a partitioning board abutting inner faces of two boards, respectively. A chamber is defined between the partitioning board and one of the two boards. Another chamber is defined between the partitioning board and another of the two boards and intercommunicates with the chamber via an intercommunication port and a backflow port of the partitioning board. A pump drives a working fluid to circulate in the two chambers. Two welding channels are formed on outer faces of the two boards and surround the two chambers, respectively. The smallest distance between a channel bottom face of each annular welding channel and the inner face of a respective board having the annular welding channel is smaller than that between the inner and outer faces of the respective board. The two boards are coupled to the partitioning board along the annular welding channels by laser welding.

Abstract: A cooling device includes a partitioning board abutting inner faces of two boards, respectively. A chamber is defined between the partitioning board and one of the two boards. Another chamber is defined between the partitioning board and another of the two boards and intercommunicates with the chamber via an intercommunication port and a backflow port of the partitioning board. A pump drives a working fluid to circulate in the two chambers. Two welding channels are formed on outer faces of the two boards and surround the two chambers, respectively. The smallest distance between a channel bottom face of each annular welding channel and the inner face of a respective board having the annular welding channel is smaller than that between the inner and outer faces of the respective board. The two boards are coupled to the partitioning board along the annular welding channels by laser welding.

Abstract: A chip device is provided. The chip device includes a substrate, at least one chip, a sealing component, a heat-conducting medium, a barrier, and a heat dissipation device. The at least one chip is disposed over a first surface of the substrate and has a heat transfer surface. The sealing component covers the at least one chip and has a heat transfer area thermal contacting the heat transfer surface of the at least one chip. The heat-conducting medium is disposed over the heat transfer area of the sealing component. The barrier is disposed around and blocks the heat-conducting medium. The heat dissipation device is disposed over the heat transfer area of the sealing component and on the heat-conducting medium. The chip device can block the heat-conducting medium through the barrier to prevent the heat-conducting medium from overflowing or losing between the sealing component and the heat dissipation device.

Abstract: A cooling device includes a partitioning board abutting inner faces of two boards, respectively. A chamber is defined between the partitioning board and one of the two boards. Another chamber is defined between the partitioning board and another of the two boards and intercommunicates with the chamber via an intercommunication port and a backflow port of the partitioning board. A pump drives a working fluid to circulate in the two chambers. Two welding channels are formed on outer faces of the two boards and surround the two chambers, respectively. The smallest distance between a channel bottom face of each annular welding channel and the inner face of a respective board having the annular welding channel is smaller than that between the inner and outer faces of the respective board. The two boards are coupled to the partitioning board along the annular welding channels by laser welding.

Abstract: A rotor driving system has a rotor, a revolution sensor, a sensing circuit, a controller, and a rotor driver. The revolution sensor is configured to sense a revolution frequency of the rotor so as to generate a measurement signal. The sensing circuit is electrically connected to the revolution sensor and configured to convert the measurement signal into a current revolution measured value. The controller is electrically connected to the sensing circuit and configured to generate an estimated revolution frequency based on a historical revolution measured value, the current revolution measured value, and a reference value, and generate a rotor driving signal based on the estimated revolution frequency and a revolution control signal. The rotor driver is electrically connected to the controller and configured to drive the rotor to rotate based on the rotor driving signal.