JP2003298387A - Supporting structure for saw resonator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting structure for an SAW (surface acoustic wave) resonator, capable of solving the problem that distortion is generated in the SAW resonator made of a material different from a substrate made of a ceramic, etc., due to the difference in a linear expansion coefficient between a foreign substance, because the resonator is influenced in temperature by heat generated from an oscillator circuit mounted on a lower chamber through the substrate made of the ceramic, etc., or a partition wall, resulting in deteriorations in temperature characteristic and other characteristic of the SAW resonator, in a conventional method for bonding the SAW resonator on the substrate by applying an adhesive on the end of the SAW resonator. <P>SOLUTION: A gap is formed between the SAW resonator and the substrate on which the SAW resonator is mounted, by this supporting structure for SAW resonator. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for an SAW (surface acoustic wave) oscillator, which provides a new support structure for the SAW oscillator.

[0002]

2. Description of the Related Art Conventionally, an oscillator circuit and a SAW oscillator are completely separated by using a partition wall or a substrate, and each is mounted on a SAW oscillator having a so-called H-shaped structure and housed in a container made of ceramic or the like. In the SAW oscillator, as shown in FIG. 4, on the upper container in FIG. 4 of the SAW oscillator in which an H-shaped structure is formed by using ceramic or the like for the material of the oscillator container, that is, on the ceramic substrate that is the bottom of the upper chamber, It was common to use a support structure for the SAW oscillator that is fixed to the ceramic substrate by using an adhesive at the end of the SAW oscillator.

Further, in the SAW oscillator housed in the upper chamber of the SAW oscillator having the above-mentioned H-shaped structure, ceramic or the like is used as the substrate material of the container of the SAW oscillator, and the shielding effect is provided on the ceramic substrate. In order to raise the height, a conductive metal metallization layer is formed on the bottom plate and side surface of the inner surface of the container, and the SAW oscillator is fixed on the ceramic substrate using an adhesive on the edge of the SAW oscillator on the plane of the bottom plate. In addition, it has been common to mount a metallic lid called a lid using a conductive sealing material such as a brazing material, solder or a conductive adhesive to seal the SAW oscillator.

In the H-type SAW oscillator, like the SAW oscillator housed in the upper chamber, a partition or substrate made of ceramic or the like is used as shown in FIG. An oscillator circuit composed of an integrated circuit is housed. The SAW oscillator in the upper chamber and the oscillation circuit in the lower chamber are electrically connected through the ceramic partition or substrate, and through the laminated metallized layer formed in the ceramic partition or substrate, and the SAW oscillator is configured as a whole. .

[0005]

However, in recent years, electronic parts are mounted on the market, and the size of the outer shape of the container is drastically reduced with the downsizing of the equipment to be used. There is a demand, and as a result, the thickness of the substrate such as ceramic or the partition wall is as thin as possible.

Therefore, in the conventional method of using an adhesive agent at the end portion of the SAW oscillator on the ceramic substrate of the SAW oscillator and fixing the SAW oscillator on the ceramic substrate so as to be in close contact with the substrate. The difference in the linear expansion coefficient of different substances is caused by a SAW oscillator made of a material different from that of the substrate, such as ceramic, which is affected by the temperature of the oscillator circuit mounted in the lower chamber through the substrate or partition made of ceramic, etc. However, there is a problem in that the temperature characteristics and other characteristics of the SAW oscillator deteriorate as a result.

The present invention has been made under such a technical background. Therefore, it is an object of the present invention to provide a new support structure for a SAW oscillator which solves the above mentioned problems.

[0008]

To achieve the above object, the present invention is characterized in that a gap is provided between a SAW oscillator and a substrate on which the SAW oscillator is mounted.

According to the present invention, the gap between the SAW oscillator and the substrate is made of a first convex portion made of alumina ceramic, glass or metal.
A second end made of silicon resin or the like at the end of the SAW oscillator facing the first convex portion in the longitudinal direction of the SAW oscillator.
It is characterized by having a convex part of.

Further, according to the present invention, the thickness of the first convex portion is
40 μm to 200 μm, and the first and second convex portions are located outside the half of the width of the reflector formed on the SAW oscillator at the longitudinal ends of the SAW oscillator. It is characterized by being present.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings. The same reference numerals in each drawing indicate the same object.

FIG. 1 shows an SAW oscillator 6 according to the present invention in which an oscillation circuit 2 and a SAW oscillator 3 are provided on the front and back of a substrate 1, and a wall 4 formed from the front and back of the substrate 1 forms a container structure. FIG. 3 is a schematic side view showing the structure of a SAW oscillator 6 in which a gap 5 is provided between the vibrator 3 and the substrate 1.

As shown in FIG. 1, an SAW oscillator 6 having an H-shaped structure
In the above, the SAW oscillator 3 housed in the upper chamber and the substrate 1 made of ceramic or the like are used, and the oscillator circuit 2 composed of an integrated circuit containing a semiconductor is housed in the lower chamber. The SAW oscillator 3 in the upper chamber and the oscillating circuit 2 in the lower chamber are electrically connected to each other via wires 13 by a laminated metallization layer formed through the ceramic substrate 1, and the SAW oscillator 6 is configured as a whole. The upper chamber and the lower chamber are hermetically sealed by the lid 12.

According to the present invention, as shown in FIG. 1, the first convex portion 7 made of an alumina ceramic, glass or metal which is an insulator has a thickness of about 40 μm to 200 μm between the substrate 1 and the lower surface of the SAW vibrator 3. Make a gap 5. At the same time, a second material made of a soft material such as silicone resin is used.
The convex portion 8 is formed. The second convex portion 8 is a SAW oscillator in a cantilevered state supported by the first convex portion 7.
When a shock is applied to the vibrator 3, it has a function of alleviating the shock. The thickness of this second convex portion 8 is the same as that of the substrate 1.
The gap between the lower surface of the SAW oscillator 3 and the gap 5 of the present invention is about 40 μm to 200 μm.

The first convex portion 7 and the second convex portion 8 are respectively
The SAW oscillator 3 is located below both ends in the longitudinal direction. Figure 2
FIG. 3 is a schematic top view of the SAW oscillator of the SAW oscillator 3 housed in the upper chamber of the SAW oscillator 6. Reflectors 9 are formed on the left and right sides of the IDT 10 on the SAW oscillator.
The convex portion 7 and the second convex portion 8 of the SAW are closer to the SA than the half position of the width of the reflector 9 shown in the perspective view of the SAW oscillator of FIG.
It is located below the longitudinal end of the W oscillator. Also, SAW
The vibrator is a non-conductive epoxy resin fixing adhesive 11
The fixing adhesive 11 is applied to the pattern on the SAW vibrator, that is, to the end of the vibrator chip that does not hang on the reflector 9 of FIGS. To do.

In the present embodiment, the SAW oscillator supporting structure in the SAW oscillator having the H-shaped structure in which the oscillation circuit constituted by the integrated circuit including a semiconductor is mounted in the lower chamber has been described. It goes without saying that such a support structure of the SAW vibrator in the SAW vibrator alone falls within the technical scope of the present invention.

[0017]

According to the present invention, in the SAW oscillator having the H-shaped structure, the temperature of the SAW oscillator housed in the upper chamber due to the heat generated by the oscillation circuit including the IC housed in the lower chamber is passed through the substrate or the partition wall. It has become possible to significantly reduce the impact.

Further, according to the present invention, the SAW vibrator made of a material different from that of the substrate such as ceramics is distorted due to the difference in the linear expansion coefficient of different substances, and as a result, the temperature characteristics and other characteristics of the SAW vibrator are generated. We were able to realize a support structure for the SAW oscillator that solves the problem of aggravation.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a support structure for a SAW oscillator according to the present invention.

FIG. 2 is a schematic side view showing the structure of a SAW oscillator including the present invention.

FIG. 3 is a schematic top view of a SAW oscillator.

FIG. 4 is a schematic perspective view of a SAW vibrator.

FIG. 5 is a schematic side view showing the structure of a conventional SAW oscillator.

[Explanation of symbols]

1 substrate 3 SAW transducer 5 gap 7 First convex part 8 Second convex part 9 reflector

Claims (3)

[Claims] 1. A SAW oscillator, comprising the SAW oscillator and the SAW oscillator.
SAW oscillator support structure characterized by having a gap between the substrates on which the oscillator is mounted. 2. A gap between the SAW oscillator according to claim 1 and the substrate is formed by a first convex portion, and the gap faces the first convex portion in the longitudinal direction of the SAW oscillator. A support structure for an SAW oscillator, characterized in that it has a second convex portion at the end of the SAW oscillator. 3. The thickness of the first convex portion according to claim 2,
from about half the width of the reflector formed on the SAW oscillator at the longitudinal ends of the SAW oscillator. SAW oscillator support structure characterized by being on the outside.