Abstract: A circuit board structure includes a substrate, a first coaxial conductive via, a second coaxial conductive via and ground vias. The substrate has a first surface and a second surface opposite to the first surface. The first coaxial conductive via and the second coaxial conductive via are disposed in the substrate. An impedance of the first coaxial conductive via and an impedance of the second coaxial conductive via are less than 50 ohms respectively. The ground vias surround the first coaxial conductive via and the second coaxial conductive via. The first coaxial conductive via and the second coaxial conductive via are configured to transfer a signal with a frequency in a range between 50 GHz and 68 GHz.

Abstract: A manufacturing method of the circuit board includes the following steps. A metal layer, a first substrate, a second substrate, and a third substrate are laminated. Multiple blind holes and a through hole are formed. A conductive material layer is formed, which covers the metal layer, the conductive layer of the third substrate, and an inner wall of the through hole, and fills the blind holes to define multiple conductive holes. The conductive material layer, the metal layer, and the conductive layer are patterned to form a first external circuit layer located on the first substrate and electrically connected to the conductive pillars, and a second external circuit layer located on the insulating layer and electrically connected to the conductive holes, and define a conductive through hole structure connecting the first external circuit layer and the second external circuit layer and located in the through hole.

Abstract: A circuit board includes a first external circuit layer, a first substrate, a second substrate, a third substrate, and a conductive through hole structure. The first substrate includes conductive pillars electrically connecting the first external circuit layer and the second substrate. The second substrate has an opening and includes a first dielectric layer. The opening penetrates the second substrate, and the first dielectric layer fills the opening. The third substrate includes an insulating layer, a second external circuit layer, and conductive holes. A conductive material layer of the conductive through hole structure covers an inner wall of a through hole and electrically connects the first and the second external circuit layers to define a signal path. The first external circuit layer, the conductive pillars, the second substrate, the conductive holes and the second external circuit layer are electrically connected to define a ground path surrounding the signal path.

Abstract: A package structure including a circuit board and a heat generating element is provided. The circuit board includes a plurality of circuit layers and a composite material layer. A thermal conductivity of the composite material layer is between 450 W/mK and 700 W/mK. The heat generating element is disposed on the circuit board and electrically connected to the circuit layers. Heat generated by the heat generating element is transmitted to an external environment through the composite material layer.

Abstract: A circuit board includes a first external circuit layer, a first substrate, a second substrate, a third substrate, and a conductive through hole structure. The first substrate includes conductive pillars electrically connecting the first external circuit layer and the second substrate. The second substrate has an opening and includes a first dielectric layer. The opening penetrates the second substrate, and the first dielectric layer fills the opening. The third substrate includes an insulating layer, a second external circuit layer, and conductive holes. A conductive material layer of the conductive through hole structure covers an inner wall of a through hole and electrically connects the first and the second external circuit layers to define a signal path. The first external circuit layer, the conductive pillars, the second substrate, the conductive holes and the second external circuit layer are electrically connected to define a ground path surrounding the signal path.

Abstract: A package structure including a circuit board and a heat generating element is provided. The circuit board includes a plurality of circuit layers and a composite material layer. A thermal conductivity of the composite material layer is between 450 W/mK and 700 W/mK. The heat generating element is disposed on the circuit board and electrically connected to the circuit layers. Heat generated by the heat generating element is transmitted to an external environment through the composite material layer.

Abstract: A manufacturing method for a circuit board and a circuit board are provided. The method includes steps: providing a substrate having a first metal layer; forming a patterned first opening on the first metal layer to expose the substrate; forming a patterned first dielectric layer on the substrate, the first dielectric layer is made of a photosensitive dielectric material and covers the first opening; photosensitizing the first dielectric layer to cure the first dielectric layer; forming a patterned second metal layer on the first metal layer; forming a patterned third metal layer on the second metal layer, and the third metal layer being adjacent to the first dielectric layer; removing a portion of the first metal layer not covered by the second metal layer; and forming a second dielectric layer on the substrate. A thickness of the third metal layer is greater than a thickness of the second metal layer.

Abstract: A method for handling a proactive command in a mobile system with a subscriber identity card, executed by a micro-processing unit (MCU) of a Baseband chip, is provided. A response code is received from the subscriber identity card, wherein the response code indicates the mobile system to fetch the proactive command for a specific procedure. It is determined whether the mobile system is under a specific condition after receiving the response code. The response code is ignored until the specific condition is absent.

Abstract: A method for dual-tone multi-frequency (DTMF) signaling is implemented in a communication device and comprises the following steps. Transmission of a DTMF event of a digit is triggered if a button-down event occurs. A packet carrying the DTMF event with assigned non-zero event duration is generated regardless of the currently-detected duration of the button-down event. The packet is transmitted over a communication channel.

Abstract: A method of establishing a communication connection of a wireless communication device operable in a wireless local area network and a cellular phone network is provided. A wireless communication device, having access to the wireless local area network and the cellular phone network, is also provided. A user preference parameter is provided. The wireless local area network or the cellular phone network is selected according to the user preference parameter. A new communication connection is established using the selected network.