Murata Manufacturing Co., Ltd.

Makoto Fujita

Toshikazu Funahara

Hiroshi Nishikawa

Akiyoshi Moriyasu

Fumikiyo Kawahara

Tadashi Kani

Akira Kato

Ikuo Tamaru

Yasuhiro Tamatani

Akiyoshi Kinoshita

In a network to which a plurality of electronic devices and a server are connected, an electronic key system controls locking and unlocking of ID information output of each electronic device. Each electronic device includes a switching device that locks or unlocks output of ID information of each electronic device. The server includes an availability changing unit and a management unit. The availability changing unit unlocks only one of the plurality of electronic devices and locks the other electronic devices. The management unit updates a state at which the locking of ID information output and the unlocking of ID information output are swapped between a pair of the electronic devices.

Electronic key system

A circuit module and a manufacturing method for the same, reduce a possibility that a defect area where an electrically conductive resin is not coated may occur in a shield layer. A mother board is prepared. A plurality of electronic components are mounted on a principal surface of the mother board. An insulator layer is arranged so as to cover the principal surface of the mother board and the electronic components. The insulator layer is cut such that grooves and projections are formed in and on the principal surface of the insulator layer and the insulator layer has a predetermined thickness H. An electrically conductive resin is coated on the principal surface of the insulator layer to form a shield layer. The mother board including the insulator layer and the shield layer both formed thereon is divided to obtain a plurality of circuit modules.

Circuit module and manufacturing method for the same

A piezoelectric oscillator unit maintains the adhesive force of a quartz vibrator package with respect to a circuit substrate even when the solder connecting the quartz vibrator package to the circuit substrate melts. This prevents the vibrator package from lifting from or falling off of the circuit substrate. In this piezoelectric oscillator unit, a quartz vibrator housing a quartz member is overlaid on a box-shaped circuit substrate on which an oscillating circuit, a temperature compensation circuit, or other circuits are mounted. The electrodes provided on the four corners of the top surface of the circuit substrate and the electrodes provided on the four corners of the bottom surface of the quartz vibrator are bonded together using solder, and also the circuit substrate and the quartz vibrator are mechanically coupled by an adhesive.

Piezoelectric oscillator unit

A piezoelectric oscillator includes a piezoelectric element, and an oscillation circuit connected to one of two terminals of the piezoelectric element. One terminal of first capacitance element of which the other terminal is grounded is connected to at least one of the two terminals of the piezoelectric element. A series circuit including a resistor, which has adjustable resistance, can be adjusted and a second capacitance element is connected in parallel to the first capacitance element.

Piezoelectric oscillator, method of producing the same, and electronic device using the piezoelectric oscillator

A quartz oscillator is constructed to achieve a better yield when being mass-produced, by providing a margin of strength for each of the substrates thereof while reducing the thickness of the quartz oscillator devices. A box-shaped circuit substrate is provided for mounting thereon circuit components having different heights from one another. The bottom plate of a recess in this circuit substrate has a level difference, and is constituted of a region where the thickness of the bottom plate is relatively larger and a region where the thickness of the bottom plate is relatively smaller. High-profile circuit components are mounted on the region where the thickness of the bottom plate is smaller, while low-profile components are mounted on the region where the thickness of the bottom plate is larger. By thus increasing the thickness of one portion of the bottom plate of the circuit substrate, the bending strength of the circuit substrate is improved.

Electronic component module and piezoelectric oscillator device

A compact quartz oscillator includes a quartz vibrator that is integrally mounted on a circuit substrate. In the quartz oscillator, flux residue can be easily washed away. A cavity is defined in the approximate center of the circuit substrate. Within the cavity, circuit components defining an oscillation circuit, a temperature-compensating circuit, and other such circuits are surface-mounted preferably via reflow soldering. Connection electrodes are disposed at the four corners of walls surrounding the cavity. The connection electrodes are bonded to electrodes of the quartz vibrator mounted on the circuit substrate preferably via reflow soldering. Recesses are provided in the top surfaces of the walls. With the recesses, clearances are created between the circuit substrate and the quartz vibrator. As a result, in order to wash away flux residue.

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Kusatsu, Japan

Makoto Fujita