JP2008252836A - Piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability of measurements of a piezoelectric vibration element. <P>SOLUTION: A piezoelectric oscillator comprises: a container body 3 in which a recess K1 including an opening is formed on one principal surface; a piezoelectric vibration element 2 mounted on a bottom surface within the recess K1; an integrated circuit element 4 mounted, in parallel with the piezoelectric vibration element 2, on the bottom surface within the recess K1; a cover 5 which air-tightly seals the recess K1; and a piezoelectric vibration element measuring pad 3C which is provided on the bottom surface of the recess K1, electrically connected with the piezoelectric vibration element 2 and provided at a position spaced apart from the piezoelectric vibration element 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device such as a portable communication device.

  Conventionally, temperature compensated piezoelectric oscillators have been used in electronic devices such as portable communication devices. For example, such a conventional temperature-compensated piezoelectric oscillator is hermetically sealed with a container body in which a frame portion is integrally formed on one main surface of a substrate and provided with a recess, a piezoelectric vibration element, and the recess of the container body. Mainly composed of a lid body to be stopped and an integrated circuit element provided with a circuit for performing temperature compensation of the piezoelectric vibration element, and the piezoelectric vibration element and the integrated circuit element are mounted in the recess of the container body Thus, the concave portion is hermetically sealed with a lid (for example, see Patent Document 1).

In the piezoelectric oscillator having such a structure, the measurement of the piezoelectric vibration element is performed by bringing the probe into contact with the mounting pad with the piezoelectric vibration element mounted on the mounting pad for the piezoelectric vibration element provided in the recess. It was.
This measurement is performed to check whether or not the piezoelectric vibration element is defective. In particular, this measurement is performed before mounting the integrated circuit element. Accordingly, even if the piezoelectric vibration element is defective, the integrated circuit element is not wasted, and the manufacturing cost can be reduced.

JP 2001-94380 (paragraph 0026, FIG. 2)

However, in such a conventional piezoelectric oscillator, when measuring the piezoelectric vibration element, there is a possibility that the probe is accidentally brought into contact with the piezoelectric vibration element and the piezoelectric vibration element is damaged.
Therefore, if the size of the piezoelectric oscillator is reduced, the measurement workability of the piezoelectric vibration element is deteriorated, the probe is easily brought into contact with the piezoelectric vibration element, and the yield may be reduced.

  Accordingly, an object of the present invention is to solve the above-described problems and improve the workability of measurement of a piezoelectric vibration element.

  The piezoelectric oscillator of the present invention includes a container body having a recess having an opening on one main surface, a piezoelectric vibration element mounted on the bottom surface in the recess, and an integrated circuit mounted on the bottom surface in the recess. An element, a lid that hermetically seals the recess, and a piezoelectric vibration element measurement pad that is provided on the bottom surface of the recess and is electrically connected to the piezoelectric vibration element. .

  The piezoelectric oscillator according to the present invention is characterized in that, in the above configuration, the piezoelectric vibration element measurement pad is provided so as to be separated from a region located below the piezoelectric vibration element on the bottom surface of the recess.

  According to the piezoelectric oscillator of the present invention, since the piezoelectric vibration element measurement pad is provided on the bottom surface of the recess at a position away from the piezoelectric vibration element, the probe is not brought into contact with the piezoelectric vibration element. The measurement workability can be improved.

Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a schematic sectional view of a piezoelectric oscillator according to an embodiment of the present invention. 2 is a plan view showing an example of a container body in which the piezoelectric vibration element and the integrated circuit element are mounted.
As shown in FIG. 1, a piezoelectric oscillator 1 according to an embodiment of the present invention mainly includes a piezoelectric vibration element 2, a container body 3 having a recess K <b> 1, an integrated circuit element 4, and a lid body 5.

  The piezoelectric vibration element 2 is made of, for example, quartz, and is configured by attaching and forming a pair of excitation electrodes 2B on both main surfaces of a piezoelectric plate 2A obtained by cutting an artificial crystalline lens along a predetermined crystal axis. When a fluctuating voltage is applied to the piezoelectric vibration element 2 via the pair of excitation electrodes 2B, thickness shear vibration is caused at a predetermined frequency.

  The integrated circuit element 4 is, for example, a flip chip type formed in a rectangular shape, and is provided on a circuit forming surface on the surface of the integrated circuit element 4 in a temperature sensing element that detects the ambient temperature state and a container body 3 described later. Based on temperature compensation data from a write terminal (not shown), a temperature compensation circuit for correcting the vibration characteristics of the piezoelectric vibration element 2 according to a temperature change, and a predetermined oscillation output connected to the temperature compensation circuit Is provided. Here, the oscillation output generated by the oscillation circuit is output to the outside of the piezoelectric oscillator 1 and then used as a reference signal such as a clock signal.

As shown in FIG. 1, an integrated circuit element side electrode pad 4A is provided on one main surface of the integrated circuit element 4, and the metal bump B is provided on the integrated circuit element side electrode pad 4A. It is joined to an integrated circuit element mounting pad 3B described later.
Then, by applying a predetermined drive voltage to the oscillation circuit configured in the integrated circuit element 4, the piezoelectric vibration element 2 has a specific resonance frequency depending on the thickness of the piezoelectric vibration element 2. An oscillation signal is output to a predetermined terminal of the terminal electrodes G through an oscillation circuit configured by the circuit element 4.

The container body 3 is formed of a multilayer substrate formed by laminating a plurality of ceramic green sheet insulating layers obtained by adding and mixing an appropriate organic solvent to a ceramic material powder made of alumina ceramics. A recess K1 is formed on one main surface of the container body 3, and the piezoelectric vibration element 2 and the integrated circuit element 4 can be arranged in parallel on the bottom surface of the recess K1.
As shown in FIG. 2, in the piezoelectric oscillator of the present invention, since the piezoelectric vibration element 2 and the integrated circuit element 4 are arranged in parallel, the thermal temperature generated from the integrated circuit element 4 and the sensitive thermal temperature of the piezoelectric vibration element 2 are It can be set as the structure which suppresses the difference of.

  As shown in FIGS. 1 and 2, a crystal vibration element mounting pad 3A, an integrated circuit element mounting pad 3B, and a crystal vibration element measurement pad 3C are provided on the bottom surface of the recess K1.

  The crystal vibration element mounting pad 3 </ b> A is formed on the bottom surface of the recess K <b> 1 corresponding to the pair of excitation electrodes 2 </ b> B provided on the crystal vibration element 2.

  The integrated circuit element mounting pad 3 </ b> B is formed on the bottom surface of the recess K <b> 1 corresponding to the integrated circuit element side electrode pad 4 </ b> A provided in the integrated circuit element 4. A plurality of integrated circuit element mounting pads 3B are provided, and a predetermined integrated circuit element mounting pad 3B among them is formed by the crystal vibration element mounting pad 3A and the internal wiring 12 provided inside the container body 3. It is electrically connected and is electrically connected to a predetermined terminal among the terminal electrodes G provided at the four corners of the container body 3.

The crystal vibration element measurement pad 3 </ b> C is provided between the adjacent integrated circuit element mounting pads 3 </ b> B and on the wall where the recess K <b> 1 of the container body 3 is formed.
Further, the crystal vibration element measurement pad 3C is in a state of being electrically connected to the crystal vibration element mounting pad 3A, so that the crystal vibration element 2 can be measured before the integrated circuit element 4 is mounted. ing.

  As a result, when the crystal resonator element 2 is defective, the integrated circuit element 4 is not wasted, and the yield can be improved, and the probe can be brought into contact with the crystal resonator element 2 in the measurement of the crystal resonator element 2. Thus, even when the piezoelectric oscillator 1 is downsized, the workability of measurement of the piezoelectric vibration element can be improved.

As shown in FIG. 1, the lid 5 hermetically seals the inside of the recess K <b> 1 with the piezoelectric vibration element 2 and the integrated circuit element 4 mounted in the recess K <b> 1 of the container body 3.
In the airtight sealing, a metallized layer is formed on the container body 5 and a seam ring 5A is formed on one main surface of the lid body 5, and the metallized layer and the seam ring 5A are brought into contact with each other. It is performed by joining in the state.

  In addition, the container body 3 is a conductor which becomes a connection pad, a terminal electrode 11 or the like on the surface of a ceramic green sheet obtained by adding an appropriate organic solvent or the like to a ceramic material powder made of alumina ceramic or the like and mixing them. The paste is printed in a predetermined pattern and applied, and a plurality of the pastes are stacked, press-molded, and then fired at a high temperature.

  In addition, the piezoelectric vibration element 2 is electrically and mechanically connected to the concave portion K1 of the container body 3 by the conductive bonding material D.

  Further, the frequency of the piezoelectric vibration element 2 may be adjusted by vapor-depositing (sputtering) Ag or the like on one excitation electrode 20 formed on both surfaces of the piezoelectric vibration element 2 or etching the excitation electrode 20.

  Further, as the material of the lid 5, for example, a metal plate having a thickness of 60 μm to 200 μm made of a metal such as 42 alloy, Kovar, or phosphor bronze may be used.

  The lid body 7 and the container body 3 are joined by, for example, placing the lid body 5 on the recess K1 and sealing both of them by conventionally known seam welding, gold tin sealing, or the like. In the bonding, it is preferable to perform the bonding in a vacuum or an inert gas atmosphere such as nitrogen gas or argon gas, so that the space in which the piezoelectric vibration element 2 and the integrated circuit element 4 are mounted is a vacuum or an inert gas. Therefore, the piezoelectric vibration element 2 and the integrated circuit element 4 can be prevented from being deteriorated due to corrosion by oxygen or moisture in the atmosphere.

In addition, this invention is not limited to the said embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
For example, in the above-described embodiment, the piezoelectric vibration element 2 and the integrated circuit element 4 are mounted one by one in the recess K1, but a composite piezoelectric element in which a plurality of piezoelectric vibration elements 2 and integrated circuit elements 4 are mounted. It does not matter as an oscillator. Needless to say, this case is also included in the technical scope of the present invention.

1 is a schematic cross-sectional view of a piezoelectric oscillator according to an embodiment of the present invention. It is a top view which shows an example of the container body which mounts a piezoelectric vibration element and an integrated circuit element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric oscillator 2 ... Piezoelectric vibration element 2B ... Excitation electrode 3 ... Container body 3C ... Piezoelectric vibration element measurement pad 4 ... Integrated circuit element 5 ... Lid 5A・ ・ Seal ring K1 ・ ・ ・ Concavity G ・ ・ ・ Terminal electrode D ・ ・ ・ Conductive bonding material 12 ・ ・ ・ Internal wiring

Claims (2)

A container body formed with a recess having an opening on one main surface;
A piezoelectric vibration element mounted on the bottom surface in the recess,
An integrated circuit element mounted on the bottom surface in the recess,
A lid for hermetically sealing the recess;
A piezoelectric oscillator comprising a piezoelectric vibration element measurement pad provided on a bottom surface of the recess and electrically connected to the piezoelectric vibration element. The piezoelectric vibration element measuring pad is
On the bottom surface of the recess,
The piezoelectric oscillator according to claim 1, wherein the piezoelectric oscillator is provided so as to be out of a region located below the piezoelectric vibration element.

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