JP4441258B2 - Crystal oscillator - Google Patents

Description

          The present invention relates to a quartz crystal device, and relates to a quartz crystal resonator that performs AT-cut fundamental wave thickness shear vibration used in a crystal oscillator mainly used in a transmission system apparatus in the communication field.

          In the case of a quartz crystal resonator that has an AT-cut fundamental-wave thickness-slip vibration in which the vibration part of the conventional quartz base plate thin plate and the reinforcement part of the quartz base plate thick plate surrounding it are integrated, unnecessary spurious In order to avoid the occurrence of vibrations, it has been common to make the shape of the vibration surface as large as possible relative to the size of the electrode surface.

          On the other hand, the recent trend is centered on transmission systems in the communications field, etc., and there is a very rapid demand for miniaturization and low profile from the market, as well as weight reduction and price reduction. Is real.

Japanese Patent No. 3221609

The applicant has not found any prior art documents related to the present invention other than the prior art documents specified by the prior art document information described above by the time of filing of the present application.

          However, the thickness of the vibrating portion of the vibrator is a very thin thin plate having a thickness of about 10 μm when the main vibration frequency is 150 MHz, for example. It is also susceptible to slight mechanical distortion of the part, and the mechanical distortion changes the thickness of the thin plate of the previous vibration part, resulting in the generation of many unnecessary spurious vibrations other than the main vibration. Result.

          In view of the need for such fine processing that is highly susceptible to external influences, a crystal resonator having such a shape is formed by etching, and as described above, In general, a large number of crystal resonators each having a shape composed of a reinforcing portion of a quartz base plate thick plate surrounding the periphery are patterned on a single wafer.

          In addition, the frequency adjustment of the vibration part of the above-described very thin thin plate of each crystal resonator in which a large number of crystal resonators are patterned on one wafer is often performed by wet etching. When adjusting the frequency of the vibrating part by sequentially dropping the etchant on the vibrating surface of the crystal unit, the concave part forming the vibrating surface of the vibrating unit of the thin plate to be etched, In order to prevent the etchant from flowing into the vibration surface, as shown in FIG. 5, a process for providing an etchant stop slit between adjacent crystal oscillators as shown in FIG. Actually, it is applied to a wafer with a large number of patterns.

          Each crystal resonator in which a large number of crystal resonators are patterned on a single wafer is divided into each resonator by a scriber or the like and accommodated in a crystal resonator container. Conventionally, the quartz crystal container is supported in a cantilevered state using a conductive adhesive as shown in FIG. 4 on a support base placed on the internal substrate of the quartz crystal oscillator. Alternatively, as shown in FIG. 5, a method of wire bonding using a non-conductive adhesive together with one-point support of a crystal resonator has been adopted.

          However, when a large number of crystal resonators patterned on a wafer provided with the above-mentioned etchant stop slits are individually divided by a scriber or the like, the conventional electrode pattern as shown in FIG. There is a problem in that there is a possibility that the conduction of the crystal resonator electrode may not be ensured by cutting the front and back surfaces of the crystal resonator with a scriber or the like.

          Further, in the conventional electrode pattern as shown in FIG. 5, if there is a conductive pattern material that is an electrode material on the line of the blade line where the blade of the scriber cuts the previous wafer, the pattern material is chipped during cutting. There is a problem in that fine electrode material particles are generated and adhered to the vibration surface of the crystal unit, which may impair the reliability of the crystal unit.

          The present invention has been made on the basis of the technical background as described above. Accordingly, an object of the present invention is to provide a crystal resonator with higher reliability.

In order to achieve the above object, the present invention provides a vibrating portion of a quartz base plate thin plate in which a large number of quartz vibrators are formed on a single wafer and a reinforcing portion of a quartz base plate thick plate surrounding the periphery thereof. In an AT-cut fundamental-wave thickness-shear vibration crystal united integrally with each other, it is formed at least as long as the vibration part of the crystal element thin plate so as to surround each crystal element element on the wafer. The electrode pattern is attached to the side surface of the slit where the electrode pattern on the main surface of the quartz base plate is applied.

          According to the crystal resonator of the present invention, the electrode patterns on the front and back surfaces of the crystal resonator can reliably ensure conduction, and a more reliable crystal resonator can be manufactured.

          Further, according to the crystal resonator of the present invention, when dividing into each crystal resonator, fine electrode material particles that are chips of the pattern material are not generated. There is an effect that there is no possibility that particles of the electrode material adhere to the vibration surface of the crystal unit and impair the reliability of the crystal unit.

          Further, according to the crystal resonator of the present invention, the manufacturing yield of the crystal resonator can be remarkably increased, and the manufacturing cost can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In addition, the same code | symbol in each figure shall show the same object.

          FIG. 1 is a schematic top view of a crystal resonator 3 according to the present invention as viewed from above. In this figure, the portion that enters the frame of each slit 9 and is painted black is actually an electrode pattern 4 that is not visible from the top surface and is attached to the side surface of each slit on the crystal resonator 3 side. The other electrode patterns 4 are patterned so as not to generate chips when cutting with a blade (blade) when dividing from the wafer 5, avoiding the scribe line 6 as shown in the figure. . As described above, according to the crystal resonator 3 of the present invention, fine electrode material particles, which are chips of the pattern material, are not generated when the crystal resonators 3 are individually divided. There is an effect that there is no possibility that the fine electrode material particles adhere to the vibration surface 1 of the crystal unit 3 and impair the reliability of the crystal unit 3. In addition, the electrode pattern 4 on the crystal unit 3 is formed by vapor deposition or sputtering.

          FIG. 2 is a schematic top plan view of the previous wafer 5 as seen from above, showing how many crystal resonators 3 of the present invention are formed on a single wafer 5. In addition, the inside of the circle of the dotted line of this figure is a side sectional view of the enlarged long side direction of the crystal resonator 3 of the enlarged wafer 5.

          FIG. 3 is a schematic side sectional view of the wafer 5 shown in FIG. 2 as viewed from the short side direction of each crystal resonator 3 formed on the wafer 5. As can be seen from this figure, when adjusting the frequency of the vibrating plate 1 of the thin plate by sequentially dropping the etchant on the adjacent crystal unit 3, the slit 5 ensures that the etchant flows into the vibrating plate 1 of the other thin plate. It is to suppress.

          FIG. 4 is a schematic top view of the crystal resonator 3 viewed from the short side direction, showing a conventional pattern in which the crystal resonator 3 is placed on the support base 13 in a cantilevered state using the conductive adhesive 12. It is a perspective view. 1 shows an embodiment in which a wafer 5 on which a large number of crystal resonators 3 are formed is divided and stored in a container of the crystal resonator 3.

          FIG. 5 is a schematic diagram of another conventional crystal resonator 3 as viewed from above. In this figure, a non-conductive adhesive is used, and although not shown in the figure, the crystal unit 3 is placed on the support base 13 in a cantilever state, and an electrode is formed by using the wire bonding 14 FIG. 6 is a schematic top perspective view seen from the short side direction of the crystal unit 3, showing a pattern in which the output of the crystal unit 3 is connected to an external circuit.

1 is a schematic top view of a crystal resonator according to the present invention as viewed from above. FIG. 3 is a schematic top view of the previous wafer as seen from above, showing how a large number of crystal resonators of the present invention are formed on a single wafer. The dotted circle in this figure is a schematic side sectional view of an enlarged wafer. FIG. 3 is a schematic side cross-sectional view of the wafer of FIG. 2 as viewed from the short side direction of each crystal resonator formed on the wafer. It is the general | schematic top perspective view seen from the short side direction of the crystal oscillator which shows the conventional pattern which mounts a crystal oscillator on a support stand in the cantilever state using a conductive adhesive. It is the general | schematic upper surface perspective view seen from the short side direction of the conventional crystal oscillator. This figure shows a pattern in which a non-conductive adhesive is used to place a crystal unit in a cantilevered state on a support base, and the electrode output is connected to an external circuit using wire bonding. It is a schematic top perspective view seen from the short side direction of a vibrator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin plate vibration part 2 Thick plate reinforcement part 3 Crystal oscillator 4 Electrode pattern 5 Wafer 6 Scribe line 7 Crystal base plate 8 Length of vibration part 9 Slit 10 Main surface 11 Slit side surface 12 Conductive adhesive 13 Support stand 14 Wire bonding

Claims (1)

An AT-cut fundamental wave thickness slide in which a large number of crystal resonators are formed on a single wafer, and the vibration part of the quartz base plate thin plate and the reinforcement part of the quartz base plate thick plate surrounding it are integrated. In a crystal resonator that vibrates,

The slit side surface of the slit formed in at least the length of the vibrating portion of the quartz plate thin plate so as to enclose each quartz plate on the wafer is on the side surface of the slit on which the electrode pattern of the quartz plate main surface is applied. A crystal resonator having an electrode pattern.

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