Abstract: A method and a system for stacking printed circuit boards includes providing a lower baseboard, a pinboard, and an upper baseboard; printing a first solder paste on the lower baseboard; placing a placement component on the lower baseboard; placing the pinboard on the lower baseboard; reflow soldering the lower baseboard with the placement component and the pinboard and forming a first assembly; printing the first solder paste and a second solder paste on the upper baseboard; placing the placement component on the upper baseboard and the first assembly on the upper baseboard; and reflow soldering the upper baseboard with the placement component and the first assembly and forming a printed circuit board; a melting point of the first solder paste is higher than a melting point of the second solder paste.

Abstract: A method and a system for stacking printed circuit boards includes providing a lower baseboard, a pinboard, and an upper baseboard; printing a first solder paste on the lower baseboard; placing a placement component on the lower baseboard; placing the pinboard on the lower baseboard; reflow soldering the lower baseboard with the placement component and the pinboard and forming a first assembly; printing the first solder paste and a second solder paste on the upper baseboard; placing the placement component on the upper baseboard and the first assembly on the upper baseboard; and reflow soldering the upper baseboard with the placement component and the first assembly and forming a printed circuit board; a melting point of the first solder paste is higher than a melting point of the second solder paste.

Abstract: A mobile device and a corresponding proximity detection method are provided. The mobile device includes an infrared emitter and a proximity sensor. The infrared emitter emits an infrared using first power in a first mode or emits the infrared using second power in a second mode. The first power and the second power are different. The proximity sensor detects the reflection of the infrared and determines whether or not there is an object in close proximity to the mobile device based on the reflection.

Abstract: A mobile device is provided. The mobile device includes a transceiver, a sensor unit, a storage device and a processor. The sensor unit detects the position and the motion of the mobile device to provide sensor data. The storage device stores activity records. The processor obtains an identification code of the base station connected to the mobile device through the transceiver and calculates the height of the mobile device according to the sensor data. When the identification code of the base station and the height of the mobile device match those in an activity record, the processor executes a predetermined function corresponding to the activity record. When the execution of the predetermined function fails, the processor generates a moving trail of the mobile device according to the sensor data. When the moving trail of the mobile device matches that in the activity record, the processor executes the predetermined function.

Abstract: A mobile device and a corresponding proximity detection method are provided. The mobile device includes an infrared emitter and a proximity sensor. The infrared emitter emits an infrared using first power in a first mode or emits the infrared using second power in a second mode. The first power and the second power are different. The proximity sensor detects the reflection of the infrared and determines whether or not there is an object in close proximity to the mobile device based on the reflection.

Abstract: A mobile device is provided. The mobile device includes a transceiver, a sensor unit, a storage device and a processor. The sensor unit detects the position and the motion of the mobile device to provide sensor data. The storage device stores activity records. The processor obtains an identification code of the base station connected to the mobile device through the transceiver and calculates the height of the mobile device according to the sensor data. When the identification code of the base station and the height of the mobile device match those in an activity record, the processor executes a predetermined function corresponding to the activity record. When the execution of the predetermined function fails, the processor generates a moving trail of the mobile device according to the sensor data. When the moving trail of the mobile device matches that in the activity record, the processor executes the predetermined function.

Abstract: A mobile device, a positioning method and a computer-readable recording medium are provided. The mobile device includes a display, a sensor unit, a transceiver unit, and a processor. The sensor unit provides internal sensor data. The transceiver unit receives at least one external positioning data. The processor calculates a position of the mobile device based on the internal sensor data. The processor obtains a position corresponding to each of the external positioning data based on each of the external positioning data and controls the display to display multiple representative objects. Each of the representative objects is corresponding to one of the positions of the mobile device or the at least one external positioning data.

Abstract: A handheld electronic device has a display side and a back side opposite to the display side. The handheld electronic device includes a case, a host system, an optical device, an opening region, and a liquid crystal light valve. The host system and the optical device are disposed in the case, and the optical device is electrically coupled to the host system. The opening region is located on the display side or the back side to expose the optical device. The liquid crystal light valve is disposed in the opening region and is electrically coupled to the host system to control the luminous flux passing through the opening region.

Abstract: The present invention discloses a portable electronic device and a control method thereof. The portable electronic device includes a main body, a proximity sensor, a first speaker, a first microphone, an orientation sensor, and a processor. The main body includes first and the second sides opposing to each other. The proximity sensor, the first speaker, and the first microphone are disposed in the first side region. The orientation sensor is configured to determine an orientation of the main body. When the orientation represents that the second side is higher than the first side, the processor disables the proximity sensor and the first speaker, and it enables the first microphone to detect the received sound volume as the basis of a proximity sensing function.

Abstract: A portable electronic device including a display device, an acceleration sensor and a processing unit is provided. The display device has a display surface. The acceleration sensor has a plurality of detecting sensor arrays for detecting a three-dimensional acceleration, and a shift angle smaller than 90 degrees is formed between at least one of the detecting sensor arrays and the display surface. The processing unit is configured to calculate a tilt angle according to the three-dimensional acceleration.

Abstract: A communication management method for a mobile communication device is provided and includes the steps of connecting first and second wireless communication units respectively to first and second service networks according to first and second information respectively provided by first and second Subscriber Identity Modules (SIMs); using first wireless communication unit to establish first call connection with remote communication device and afterward comparing qualities of first and second signals respectively received from first and second service networks; when quality of second signal is superior to quality of first signal, using second wireless communication unit to dial first SIM to establish second call connection with first wireless communication unit and afterward automatically establishing first multi-call connection among first and second wireless communication units and remote communication device; and then automatically establishing third call connection between second wireless communication unit

Abstract: A communication management method for a mobile communication device is provided and includes the steps of connecting first and second wireless communication units respectively to first and second service networks according to first and second information respectively provided by first and second Subscriber Identity Modules (SIMs); using first wireless communication unit to establish first call connection with remote communication device and afterward comparing qualities of first and second signals respectively received from first and second service networks; when quality of second signal is superior to quality of first signal, using second wireless communication unit to dial first SIM to establish second call connection with first wireless communication unit and afterward automatically establishing first multi-call connection among first and second wireless communication units and remote communication device; and then automatically establishing third call connection between second wireless communication unit

Abstract: A portable electronic device including a display device, an acceleration sensor and a processing unit is provided. The display device has a display surface. The acceleration sensor has a plurality of detecting sensor arrays for detecting a three-dimensional acceleration, and a shift angle smaller than 90 degrees is formed between at least one of the detecting sensor arrays and the display surface. The processing unit is configured to calculate a tilt angle according to the three-dimensional acceleration.

Abstract: A handheld electronic device has a display side and a back side opposite to the display side. The handheld electronic device includes a case, a host system, an optical device, an opening region, and a liquid crystal light valve. The host system and the optical device are disposed in the case, and the optical device is electrically coupled to the host system. The opening region is located on the display side or the back side to expose the optical device. The liquid crystal light valve is disposed in the opening region and is electrically coupled to the host system to control the luminous flux passing through the opening region.