Nihon Dempa Kogyo Co., Ltd.

Hiroaki Mizumura

Hidenori Harima

Kouichi Moriya

Takeo Oita

Akio Yamazaki

Kenichi Sugawara

Yoshinori Ishito

A surface mount type crystal oscillator comprises: a package body comprised of laminated ceramic including a flat central layer made up of a first layer and a second layer, and a first and a second frame layer; a crystal blank hermetically sealed in a first recess defined by the first layer and the first frame layer; an IC chip placed in a second recess defined by the central layer and second frame layer; and a shield electrode disposed on a laminated surface of the second layer with the first layer. First and second electrode through-holes are formed through the first layer and second layer, respectively, for electrically connecting the crystal blank to the IC chip. The first and second electrode through-holes are positioned in areas outside the mounting position of the IC chip on the second recess.

Surface mount type crystal oscillator

A surface mount type temperature-compensated crystal oscillator includes a crystal blank; an IC chip integrating an oscillation circuit using the crystal blank and a temperature compensation mechanism of compensating frequency temperature characteristics of the crystal blank; and a substantially rectangular parallelepiped container body for surface mounting having a first recess of housing the crystal blank and a second recess of housing the IC chip. Respective side surfaces corresponding to the long sides of the container body are provided with crystal inspection terminals for inspecting oscillation characteristics of the crystal blank and respective side surfaces corresponding to the short sides are provided with data writing terminals for writing temperature compensation data to the temperature compensation mechanism. A conductive path electrically connecting the IC chip to the crystal inspection terminal is formed to be shorter than a conductive path electrically connecting the IC chip to the data writing terminal.

Surface mount type temperature-compensated crystal oscillator

A surface mount type crystal oscillator includes: a container body composed of a laminated ceramic including a plate-shaped center layer, and first and second frame layers stacked on opposite surfaces of the center layer respectively; a crystal blank hermetically sealed in a first recess formed by the first frame layer and the center layer; an IC chip accommodated in a second recess formed by the second frame layer and the center layer; and a test terminal provided on the outer side surface of the container body and used to test the crystal blank. The center layer has at least a first layer and a second layers, and the test terminal is electrically connected to a crystal retaining terminal provided on the bottom surface of the first recess in order to retain the crystal blank through a conductive path provided on an interface between the first and second layers.

A temperature compensated crystal oscillator has a package body, a crystal blank hermetically sealed in a first recess of the package body, and an IC chip which includes an oscillation circuit electrically connected to the crystal blank, and a temperature compensating mechanism for compensating the crystal blank for the frequency-temperature characteristic. The oscillation circuit and temperature compensating mechanism are integrated into the IC chip. The IC chip is received in a second recess of the package body such that a circuit formation surface thereof faces the bottom face of the package body. External write terminals are formed on a principal surface of the IC chip, which is not the circuit formation surface, for writing temperature compensation data into the temperature compensating mechanism.

Temperature compensated crystal oscillator and method of manufacturing same

A surface-mount crystal oscillator includes a quartz crystal unit, a mounting substrate on which an IC (Integrated Circuit) chip is mounted and which is bonded to the rear surface of the crystal unit, and an electronic components which is mounted on one end of the surface of the mounting substrate on which the crystal unit is bonded. The crystal unit includes a planar substrate, a quartz crystal blank held on one principal surface of the planar substrate, a metal film formed along the outer periphery of the principal surface, and a concave metal cover having an open-ended face. In the crystal unit, the open-ended face of the metal cover is brazed to the metal film, whereby the crystal blank is hermetically sealed between the metal cover and the planar substrate.

Surface-mount crystal oscillator

A surface-mounted crystal oscillator has a quartz crystal unit and a receptacle which is joined to the rear surface of the crystal unit for accommodating an IC (Integrated Circuit) chip. The receptacle has a bottom wall and sidewalls, and further, a concavity formed in at least one of its principal surfaces. The sidewalls surrounding the concavity are opened on at least one end of the receptacle, and at this opened end, the bottom wall is exposed and a notch portion is formed in the bottom wall.

Surface-mount crystal oscillator having an opened portion of the sidewalls

A surface-mount crystal oscillator includes a crystal unit housing and an element housing which is provided on the base side of the crystal unit housing. A crystal blank is accommodated and hermetically sealed in the crystal unit housing. A concavity having an open side is formed in the element housing, and an IC chip is secured to the bottom surface of the concavity by means of face-down bonding. Notch portions or recess portions which are adjoining and connecting to the concavity and which are used for injecting fluid resin are formed in the frame portion at the periphery of the concavity. Fluid resin is injected to the bottom surface of the concavity by way of the notch portions and cured to form a protective resin layer of the IC chip.

A sheet substrate for use in manufacturing surface-mount crystal oscillators has a plurality of container bodies fabricated thereon. Each of the container bodies is capable of accommodating at least one IC chip, and has a bottom face formed with a plurality of mount terminals and a top face which is capable of forming a crystal unit thereto. On the sheet substrate, each of the container bodies has a conductive path extending from the container body to an adjacent container body and connected to a mount terminal of the adjacent container body, and a chip carrying terminal connected to one end of the conductive path for use in electric connection with the IC chip.

Sheet substrate for crystal oscillator and method of manufacturing surface-mount crystal oscillators using same

A thermistor network for a low temperature component of a temperature compensating circuit includes a series resistor-capacitor combination in parallel with a thermistor and a capacitor. The presence of the capacitor in series with the resistor permits DC measurement of the resistance of the resistor without the measurement being affected by current flow through the thermistor. This low temperature component may be connected in series with a high temperature component of the temperature compensating circuit. Alternatively, the low temperature component can be connected in parallel with the high temperature component.

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Saitama, Japan

Hiroaki Mizumura