JP2004128591A - Piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a downsized piezoelectric oscillator with a simplified structure at a reduced manufacturing cost. <P>SOLUTION: The piezoelectric oscillator comprises a piezoelectric vibrator wherein an exciting electrode is formed on a piezoelectric raw substrate and semiconductor integrated components forming an oscillation circuit. The piezoelectric oscillator is characterized in that the piezoelectric vibrator is directly mounted on the semiconductor integrated components and connected to them, and a cover is placed to cover the piezoelectric vibrator from the upper part of the semiconductor integrated components. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for reducing the size of a piezoelectric vibrator and a piezoelectric oscillator formed by a semiconductor integrated circuit forming an oscillation circuit.
[0002]
[Prior art]
A piezoelectric oscillator using a piezoelectric vibrator such as a crystal vibrator is widely used in various electronic devices such as a communication device such as a mobile phone and a personal computer. With the miniaturization of electronic devices, various ideas for miniaturization of piezoelectric oscillators have been made in order to increase the component mounting density on printed wiring boards, like other various electronic components.
[0003]
A conventionally used piezoelectric oscillator has a printed pattern for an oscillation circuit arranged on a laminated substrate, and a piezoelectric element hermetically sealed with semiconductor components such as a capacitor, a resistor, and an integrated circuit which constitute the oscillation circuit on the same plane of the laminated substrate. Piezoelectric oscillator in a form in which a vibrator is mounted to form a piezoelectric oscillator (for example, Patent Document 1), or in a form in which a piezoelectric vibrator and a piezoelectric oscillator are arranged on the front and back of a container substrate that houses the piezoelectric oscillator (for example, Patent Document 2) Was used.
[0004]
In short, when the piezoelectric vibrator and the semiconductor integrated circuit are accommodated in one package, it is more advantageous to arrange them one above the other than to arrange them side by side in the package, in order to realize miniaturization. Therefore, in recent years, a configuration in which a piezoelectric vibrator and a semiconductor integrated circuit are arranged on the front and back surfaces of a substrate has been mainly used at present. In recent years, in order to achieve further miniaturization, the present invention has reached an invention in which a piezoelectric vibrator is directly mounted on a semiconductor integrated circuit, integrated, and housed in a container (for example, Patent Document 3). .
[0005]
The applicant has not discovered prior art documents related to the present invention other than the prior art documents specified by the prior art document information described in the present specification by the time of filing the present application.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-077944 [Patent Document 2]
JP 07-106901 A [Patent Document 3]
JP 2000-196360 A
[Problems to be solved by the invention]
However, even in the above-described conventional piezoelectric oscillator, particularly when the piezoelectric vibrator and the semiconductor integrated circuit are integrated, the outer dimensions of the container are still approaching the limit of miniaturization of the piezoelectric oscillator.
[0008]
This is because, in particular, recent mobile terminals have become extremely small and very thin. Until now, mobile phones were typically represented by mobile terminals, but nowadays, personal computers have become so small that they can be carried around, and card-type communication boards have become widespread as communication terminals for such computers. ing.
[0009]
Since these communication boards are required to be even smaller and thinner than the above-mentioned mobile phones, the demand for ultra-small and ultra-thin piezoelectric oscillators mounted on these communication boards is also increasing. I have.
[0010]
[Means for Solving the Problems]
In order to solve these demands, the present invention provides a piezoelectric oscillator comprising a piezoelectric vibrator having an excitation electrode formed on a piezoelectric element plate and a semiconductor integrated component having an oscillation circuit formed therein. A piezoelectric oscillator is characterized in that a transducer is directly mounted and connected, and a lid is arranged so as to cover the piezoelectric vibrator from above the semiconductor integrated component. And, between the semiconductor integrated component and the piezoelectric vibrator, at least two electrodes for electrically connecting the two are provided, and a conductive adhesive is used for electrical connection. Is what you do.
[0011]
In short, the present invention is to mount a piezoelectric vibrator directly on a semiconductor integrated circuit as a component of a piezoelectric oscillator in order to further reduce the size of a portable piezoelectric oscillator disclosed in JP-A-2000-196360 described in the related art. Conventionally, this state was housed in a container to form a hermetically sealed structure, and a piezoelectric vibrator was mounted on a semiconductor integrated component, and the piezoelectric vibrator was covered. As described above, the lid is disposed on the semiconductor integrated component to maintain the airtightness, thereby eliminating the need for a conventional container.
[0012]
Compared to the conventional piezoelectric oscillator, the board components are mounted on the customer's mounting board as a container, and the semiconductor integrated circuit is also used. , And weight reduction by reducing these components can be realized. In the background of the present invention, a piezoelectric vibrator and a semiconductor integrated component which constitute a piezoelectric oscillator tend to be reduced in external dimensions of the piezoelectric vibrator. The semiconductor integrated circuit that drives the piezoelectric oscillator of the present invention is larger than the piezoelectric vibrator because the area ratio of the semiconductor integrated circuit is increased due to multi-functionality such as the addition of a temperature compensation circuit. Was made.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same reference numeral indicates the same object. FIG. 1 is a perspective view showing an example of a piezoelectric oscillator 7 according to the present invention. FIG. 1 (a) is a developed view, FIG. 1 (b) shows a combined concept, and FIG. It is sectional drawing which shows AA part.
[0014]
As shown in FIG. 1, a piezoelectric oscillator 7 according to the present invention is a piezoelectric oscillator 7 comprising a piezoelectric vibrator 3 having an excitation electrode 2 formed on a piezoelectric element plate 1 and a semiconductor integrated component 6 having an oscillation circuit. The piezoelectric oscillator 7 has a configuration in which the piezoelectric vibrator 3 is directly mounted and connected to the semiconductor integrated component 6, and the lid 4 is arranged so as to cover the piezoelectric vibrator 3 from above the semiconductor integrated component 6. is there.
[0015]
The piezoelectric element 1 depicted in FIG. 1 is made of, for example, a quartz material, and an excitation electrode for oscillating and driving the piezoelectric material is formed on a main surface thereof. On the other hand, in addition to the circuit configuration in which the semiconductor integrated component 6 integrates, for example, an inverter, a feedback resistor, and a capacitor, it is also an essential condition that the piezoelectric oscillator 7 used in a mobile terminal such as a mobile phone has a temperature compensation function. , And a temperature compensation circuit.
[0016]
In order to approximate the original temperature characteristic of the piezoelectric vibrator 3 to a flat characteristic with respect to a change in ambient temperature, temperature compensation is recently performed based on the concept of a cubic function generation circuit. Is the mainstream. Also, since the cubic function generating circuit is characterized by having a large number of analog circuit parts, the semiconductor integrated circuit naturally has a smaller outer dimension than the speed at which the outer shape of the piezoelectric vibrator 3 is reduced in size. It tends to be difficult.
[0017]
Then, the piezoelectric vibrator 3 is directly covered by placing the piezoelectric vibrator 3 directly on the semiconductor integrated component 6 and covering the piezoelectric vibrator 3 from above the semiconductor integrated component 6. It takes the form of a piezoelectric oscillator 7 together with the integrated circuit 6.
At this time, at least two electrodes 5 for electrical connection are provided between the semiconductor integrated component 6 and the piezoelectric vibrator 3, and a conductive adhesive 9 is used for electrical connection. The lid 4 is formed by directly placing a metal, ceramic, or the like on a semiconductor integrated circuit and fixing the same. Note that an adhesive 10 or the like is used to fix the lid 4. This situation is depicted in FIG. 2 in a sectional view.
[0018]
As described above, the present invention relates to a piezoelectric oscillator 7 having a structure in which the piezoelectric vibrator 3 is directly mounted on the semiconductor integrated circuit and integrated, and the lid 4 is covered on the semiconductor integrated component 6 so as to cover the piezoelectric vibrator 3. For mounting on a mounting board of a user, a connection electrode 8 is arranged on the surface of the semiconductor integrated circuit opposite to the mounting surface of the piezoelectric vibrator 3, and the connection electrode 8 allows electrical connection with the mounting board of the user. The connection is realized.
[0019]
In the present embodiment, the conductive adhesive 9 is used for the electrical connection between the semiconductor integrated circuit and the piezoelectric component. A technique may be used. Similarly, the fixing of the lid 4 is not limited to the adhesive. Then, for mounting on the mounting board by the user, the connection electrode 8 is electrically connected to the connection electrode 8 by flip chip bonding or the like. In addition, by coating the entire semiconductor integrated circuit 6 with a resin or the like as needed, the effect of improving the moisture resistance of the piezoelectric oscillator can be achieved.
[0020]
【The invention's effect】
According to the present invention, since the members constituting the piezoelectric oscillator can be realized by the combination of the integrated circuit element, the piezoelectric vibrator, and the lid covering the piezoelectric vibrator, the piezoelectric oscillator itself can be reduced in size, height, and weight. . In addition, the cost of the piezoelectric oscillator can be reduced by removing the container portion from the components constituting the piezoelectric oscillator.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a conceptual diagram of a piezoelectric oscillator according to the present invention.
FIG. 2 is a cross-sectional view illustrating a piezoelectric oscillator according to the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 piezoelectric element plate 2 excitation electrode 3 piezoelectric vibrator 4 lid 5 electrode 6 semiconductor integrated component 7 piezoelectric oscillator

Claims (2)

In a piezoelectric oscillator comprising a piezoelectric vibrator in which an excitation electrode is formed on a piezoelectric element plate and a semiconductor integrated component in which an oscillation circuit is formed,
A piezoelectric oscillator, wherein the piezoelectric vibrator is directly mounted on and connected to the semiconductor integrated component, and a lid is arranged so as to cover the piezoelectric vibrator from above the semiconductor integrated component. At least two electrodes for electrically connecting the semiconductor integrated component and the piezoelectric vibrator are provided between the semiconductor integrated component and the piezoelectric vibrator, and a conductive adhesive is used for electrical connection. Item 7. The piezoelectric oscillator according to item 1.

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