JP3328455B2 - Multi-mode crystal oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a crystal blank and an electrical connection method for realizing good electrical characteristics of a surface mount type multi-mode crystal resonator.

[0002]

2. Description of the Related Art In a multi-mode crystal resonator, an input / output electrode is formed on a main surface of a crystal blank, and a common electrode is formed on another main surface.
Each of the electrodes was electrically connected to the corresponding terminal of the container via a connection electrode, or fixedly serving also as a connection.

[0003]

In the prior art, the input and output electrodes and the common electrode of the crystal blank are generally arranged at substantially the center of the crystal blank in consideration of characteristics, and the connection electrodes are formed of the crystal in consideration of connection convenience. It is located at one end. The electrode and the connection electrode are connected by an extraction electrode. However, if the length of the extraction electrode is long, the characteristics are adversely affected. In particular, there has been a problem that the attenuation characteristic in which the extraction electrode connecting the common electrode and the connection electrode becomes long is significantly deteriorated.

[0004]

In order to solve the problem, the connection between the common electrode 3 and the ground is grounded over a short distance from the vicinity of the common electrode 3 by using a wire bonding method 6 in addition to the conventional connection fixing method. Has solved the problem that the attenuation characteristics are significantly deteriorated.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a multi-mode crystal resonator, a crystal blank 1 is sealed in an airtight container. A crystal blank 1 has an input / output electrode 2 on its main surface.
Are connected to the connection electrode 4 from the input / output electrode 2 via the extraction electrode 5. The connection electrodes 4 are arranged at diagonal corners of the crystal blank 1, and the connection electrodes 4 have the same connection electrodes 4 on other main surfaces and are connected by wraparound electrodes. This enables connection to the container 8 from the same plane as the other main surface on which the common electrode 1 is arranged. The common electrode 3 is arranged on the other main surface (the front surface in the drawing), and each of the connection electrodes 4 is connected to the common electrode 3 via an extraction electrode 5.
It is connected to the. The connection electrode 4 is arranged at another diagonal corner different from the connection electrode 4 of the input / output electrode 2 of the crystal blank 1. The container 8 is a container 1 in which a substrate having input / output terminals and a shield electrode 9, a frame portion, and a welding ring are laminated.
The shield electrode 9 and the welding ring 11 are electrically connected inside, and the metal lid 10 connected to the welding ring 11 also has a shield electrode 9.
And the same potential (ground). The shield electrode 9, terminals, other conductors and the like of the container 8 are formed integrally when the container 1 is fired, and a welding ring 9 is brazed to the opening of the container 1. The metallization at the position corresponding to the connection electrode 4 of the crystal blank 1 and the grounding position where the short-distance ground of the common electrode 3 is wire-bonded 6 is made thick by overlapping metallization as the crystal blank mounting base 12. The crystal blank 1 is mounted on the container 8. The container 1 is placed so that the upper left and lower right become the input / output terminals, the surface of the input / output electrode 2 of the crystal blank 1 faces the shield electrode 9 of the container 8, and the upper left and lower right are the input / output terminals. And the left two points are electrically conductive adhesive 7
And secure conduction. The two right points are connected by wire bonding 6. FIG. 4 shows an example of the attenuation characteristic outside the pass band of the multimode crystal resonator in the 90 MHz band. FIG. 4A shows a case where there is no ground connection by wire bonding near the common electrode, and FIG.
2 shows a case where a ground connection is provided by wire bonding near the common electrode. Usually, from the nominal frequency f _0-
Since 910 kHz is the image frequency, the amount of attenuation at this position is a rough guide.
In FIG. 4A, the attenuation is about 55 dB.
4B, the attenuation is about 78 dB, and the attenuation characteristic of FIG. 4B is improved about 23 dB.

In the wire bonding in the vicinity of the common electrode, an overlapping metallization on the bottom surface of the container as a crystal piece mounting base is formed under the crystal piece so as to support the crystal piece during wire bonding. ing. The overlap between the metallization and the quartz piece is a rough guide at the approximate center of the edge of the common electrode and the edge of the quartz piece. However, the overlap width can be actually used from the edge of the quartz piece to the edge of the common electrode.

As shown in FIG. 2, the metallization of the crystal blank 1 and the crystal blank mounting base 12 is usually in the position indicated by the solid line, so that they are in contact with each other. Even if the overlapping metallizations as 12 are arranged in an overlapping manner, there is no effect. Since this gap is relatively small, the crystal blank 1 is pushed by the capillary during wire bonding and descends to the position indicated by the dotted line, and is pressed against the overlapping metallization as the crystal blank mounting base 12 below the crystal blank 1, whereby the crystal blank 1 is pressed. And performs the role of a table, and secure wire bonding 6 is performed. When the wire bonding 6 is completed and the capillary is separated from the crystal blank 1, the crystal blank 1 also returns to the original position indicated by the solid line and separates from the metallized layer of the crystal blank mounting base 12. The above is merely an example, and the present invention is effective even in the case of another pattern position or shape.

[0008]

According to the present invention, since a short distance can be connected by wire bonding from the vicinity of the common electrode of the quartz piece to the ground in the container, the attenuation characteristic outside the pass band is remarkably improved, so that a good multi-mode quartz crystal is obtained. In addition to the fact that the resonator can be easily obtained, the provision of metallization as a crystal blank mounting base reduces breakage and characteristic defects, making it possible to provide a low-cost and highly reliable multi-mode crystal resonator. Became.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment according to the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of FIG. 1 showing an embodiment of the present invention;
FIG.

FIG. 3 is a plan view of the bottom surface of the container showing the embodiment of the present invention.

FIG. 4A is a cross-sectional view showing an embodiment of the present invention in which a resist film is formed in an etching groove. FIG.
(B) is a cross-sectional view showing an embodiment of the present invention in which a resist film is formed in an etching groove.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 crystal blank 2 input / output electrode 3 common electrode 4 connection electrode 5 extraction electrode 6 wire bonding 7 conductive adhesive 8 container 9 shield electrode 10 metal lid 11 welding ring 12 crystal mounting base 13 metallization

Claims (1)

(57) [Claims] An input / output device is provided on one main surface of a rectangular crystal element.
An electrode is formed, a common electrode is formed on the other main surface,
And four shorts of the quartz piece from the input / output electrode and the common electrode.
Drawer that is pulled out so that it does not face the main surface up to the edge corner
Electrodes are formed, the quartz piece is disposed inside, and
A shield electrode is placed on the inner bottom surface of the crystal
A container in which the poles are formed, and contact around the opening of the container.
A welding ring connected to earth potential and gold
Metal cover, and fixing and attaching the quartz piece to the container.
Pneumatic connection causes the main surface on the input / output electrode forming side to
It is arranged to face the shield electrode, and
One of the poles is formed at the two corners of the short side of the quartz piece.
The formed extraction electrode is fixed and conductive with a conductive adhesive.
And the other two short edges of the quartz piece are formed at the corners of the short edge.
The formed extraction electrode is formed by the first wire bonding.
Multimode quartz resonator with only conduction
And each of the pulls drawn from the common electrode to the short side of both quartz pieces.
A second wire from a position near the common electrode of the output electrode
Electrically connected to ground by bonding, and
The water to a position near the second wire bonding.
The crystal blank mounting base is extended below the crystal blank.
A multi-mode crystal resonator characterized by the following.