JP2006186463A - Piezoelectric vibrator and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator capable of maintaining hermetical sealing property even if a resin substrate is used, and a method of manufacturing the piezoelectric vibrator capable of improving productivity by simplifying an assembling process. <P>SOLUTION: The manufacturing method includes a process A in which a master substrate having a plurality of substrate regions arranged in matrix is prepared, and a thin film is formed on a portion other than a wiring pattern on the master substrate by a sputtering method; a process B in which a piezoelectric element is mounted on each of the substrate regions, lids each corresponding to each of the substrate regions in a one-to-one relationship are placed on the master substrate so that piezoelectric vibration element may be sealed, and the master substrate is sealed and bonded; and a process C of simultaneously obtaining a plurality of piezoelectric vibrators by integrally cutting the substrate along the periphery of each of the substrate regions of the master substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric vibrator used in an electronic device such as a portable communication device or an electronic computer, and a manufacturing method thereof.

  Conventionally, crystal resonators have been used in electronic devices such as portable communication devices and electronic computers. As such a conventional crystal resonator, for example, as shown in FIG. 4, a pair of electrodes electrically connected to the mounting pad via a conductive adhesive on the upper surface of a container body 21 provided with a pair of mounting pads. By attaching a crystal resonator element 22 having an excitation electrode and a seal ring 23 surrounding the previous crystal resonator element 22, a metal lid 24 is joined to the upper portion of the seal ring 23 by seam welding or the like. A structure in which the mounting area of the crystal resonator element 25 is hermetically sealed is known. (For example, refer to Patent Document 1).

  When such an external alternating voltage is applied between the excitation electrodes of the crystal resonator element 22 via an input / output terminal provided on the lower surface of the container body 21, the crystal resonator is predetermined according to the characteristics of the crystal resonator element 22. The thickness-shear vibration is caused at the frequency, and a reference signal having a predetermined frequency is oscillated and output by an external oscillation circuit based on the resonance frequency. Such a reference signal is used as a clock signal in an electronic device such as a portable communication device.

  Further, the above-described crystal resonator container body 21 is formed by a multi-cavity method in which a large master substrate from which a plurality of container bodies 21 can be cut out is obtained to obtain individual pieces. Then, the crystal resonator element 22 and the seal ring 23 are attached to the obtained piece (container body 21), and the lid body 24 is joined to the upper part of the seal ring 23 to manufacture the crystal resonator.

The lid 24 of the crystal resonator element described above is generally obtained by dividing a large metal plate from which a plurality of lids 24 can be cut out, like the container body 21. During use, noise from the outside is shielded by maintaining the lid 24 at the ground potential. Such a lid body 24 is electrically connected to the ground terminal on the lower surface of the container body 21 through the seal ring 23 and the conductor pattern of the container body 21.
JP 2001-274649 A

  In addition, the applicant did not find any prior art documents related to the present invention by the time of filing of the present application other than the prior art documents specified by the above prior art document information.

  However, in the above-described conventional crystal resonator, there is a drawback that the reliability cannot be maintained when the container body is formed of a resin substrate because airtightness cannot be maintained.

  Further, in the above-described conventional method for manufacturing a crystal resonator, it is necessary to obtain the container body 21 by dividing the large master substrate prior to the assembly, and this member is obtained in the dividing step. As a result, the assembling process of the crystal unit becomes complicated, and there is a disadvantage that the productivity is not improved.

  Further, when the crystal unit is assembled after the container body 21 and the lid body 24 are prepared in advance as described above, an operation for holding the plurality of container bodies 21 individually on the carrier is necessary. Further, lids 24 must be individually aligned and mounted on the individual container bodies 21 held in the container, and this also has the disadvantage that the assembly process of the crystal unit becomes complicated. It was.

  The present invention has been devised in view of the above-described drawbacks, and its purpose is to improve productivity by simplifying the piezoelectric vibrator that can maintain hermetic sealing performance even when a resin substrate is used, and the assembly process. Another object of the present invention is to provide a method for manufacturing a piezoelectric vibrator that can perform the above-described process.

  In the piezoelectric vibrator of the present invention, a piezoelectric vibration element is mounted in the internal space of a rectangular container body, and a rectangular lid body that covers the opening of the container body is disposed on the top of the side wall of the container body. In the piezoelectric vibrator in which the lid and the conductor pattern provided on the top of the side wall are fixed and the piezoelectric vibration element in the container is hermetically sealed, the substrate is formed of an insulating resin in the container. The wall portion is formed of a metal member, and a thin film layer is formed on the surface of the container body.

  Also, in the method for manufacturing a piezoelectric vibrator of the present invention, a master substrate having a plurality of substrate regions arranged in a matrix is prepared, and a thin film is formed on the master substrate at a place other than the wiring pattern by a sputtering method. Step A and mounting a piezoelectric vibration element on each substrate region, and placing a lid corresponding to the substrate region on a one-to-one basis on the master substrate so that the electronic component element is sealed. Step B for sealing and bonding and Step C for simultaneously obtaining a plurality of piezoelectric vibrators by collectively cutting the master substrate and the thin film layer along the outer periphery of each substrate region.

  Furthermore, the method for manufacturing a piezoelectric vibrator according to the present invention is characterized in that an inclined wall portion is formed on an outer peripheral portion of each substrate region of the master substrate.

  Furthermore, the method for manufacturing a piezoelectric vibrator of the present invention is characterized in that the wall portion is formed by an etching method.

  According to the piezoelectric vibrator of the present invention, in the container body, the substrate portion is formed of an insulating resin, the wall portion is formed of a metal member, and the insulating thin film is formed on the surface of the container body. Therefore, even when a resin substrate is used, it is possible to maintain hermetic sealing and to ensure reliability.

  Further, according to the method for manufacturing a piezoelectric vibrator of the present invention, first, a thin film layer is formed in a portion other than the wiring pattern by sputtering in each substrate region of the master substrate. It becomes possible to improve.

  Further, when assembling the piezoelectric vibrator, the master substrate itself functions as a carrier, so that a complicated operation of individually holding the pieces divided from the master substrate by the carrier becomes unnecessary. Thereby, the assembly process of the piezoelectric vibrator is greatly simplified, and the productivity can be remarkably improved.

  Furthermore, even if the master substrate is composed of a resin substrate, by forming a thin film layer on the surface of the master substrate by a sputtering method, the hermetic sealing property of the resin substrate is improved and the resin substrate is cut. Since the dicer has little influence and no chipping occurs, the productivity can be remarkably improved.

  Furthermore, by forming the wall portion of the master substrate by an etching method, the container body can be formed at the time of substrate formation, so that productivity can be improved.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol in each figure shall show the same object.
FIG. 1 is an exploded perspective view of a crystal resonator obtained when the manufacturing method of the present invention is applied to the manufacture of a crystal resonator, and FIG. 2 is a case where the manufacturing method of the present invention is applied to the manufacture of a crystal resonator. It is sectional drawing of the obtained crystal oscillator.
The crystal resonator shown in FIGS. 1 and 2 is generally composed of a container body 1, a crystal vibration element 2 as a piezoelectric vibration element, a lid body 3, and a thin film layer 4.

The container body 1 is formed in a flat plate shape by a resin material such as glass cloth base epoxy resin, polycarbonate, epoxy resin, polyimide resin, etc., and is formed by a technique such as etching using the container body and a metal member such as copper. The wall portion 5 is formed so as to have a cavity portion that opens upward. A pair of mounting pads 6 on the bottom surface of the cavity are provided on the upper surface side, and external terminals 7 such as an input terminal, an output terminal, and a ground terminal are provided on the lower surface side.
A pair of mounting pads 6 provided on the bottom surface of the cavity portion of the container body 1 are electrically connected to excitation electrodes of a crystal resonator element 2 to be described later on the upper surface side through a conductive adhesive material 8, and the lower surface side. Thus, it is electrically connected to an input / output terminal (input terminal, output terminal) on the lower surface of the container body via a conductor pattern on the container body 1 or a via conductor inside the container body.

On the other hand, the wall portion 5 is formed of a metal member such as copper, and is electrically connected to a lid 3 to be described later on the upper surface side, and the lower surface of the container body via a via conductor inside the container body on the lower surface side. Is electrically connected to the ground terminal.
The external terminals described above are electrically connected to the circuit wiring of the external electric circuit via a conductive adhesive such as solder when the crystal resonator is mounted on an external electric circuit such as a motherboard. .

  The crystal resonator element 2 is mounted on the bottom surface of the cavity of the container body 1 described above. The crystal resonator element 2 is formed by attaching and forming a pair of excitation electrodes on both main surfaces of a crystal piece cut along a predetermined crystal axis, and an external AC voltage is applied to the crystal piece via the pair of excitation electrodes. When this occurs, a thickness shear vibration occurs at a predetermined frequency. Such a quartz-crystal vibrating element 5 is configured to electrically and mechanically connect the excitation electrodes attached to both main surfaces thereof and the corresponding mounting pads 6 on the upper surface of the container body via the conductive adhesive material 8. Is mounted on the bottom surface of the cavity of the container body 1. Further, a lid body 3 is attached to the opening periphery of the cavity portion of the container body 1.

  As the lid 3, not only a metal member such as 42 alloy, Kovar, and phosphor bronze but also a ceramic material such as glass-ceramic and alumina ceramic may be used. The lid 3 is sealed and joined with a brazing material such as gold tin (Au—Sn).

  Thus, the crystal resonator described above applies an AC voltage from the outside between the excitation electrodes of the crystal resonator element 2 via the input / output terminal provided on the lower surface of the container body 1, so that a predetermined value corresponding to the characteristics of the crystal resonator element 2 is obtained. By causing thickness-shear vibration at a frequency of ## EQU2 ## it functions as a crystal resonator, and a reference signal having a predetermined frequency is oscillated and output by an external oscillation circuit based on the resonance frequency of the crystal resonator. Such a reference signal can be used as a clock signal in an electronic device such as a portable communication device.

Next, a manufacturing method of the above-described crystal resonator will be described with reference to FIG.
(Step A) First, as shown in FIG. 3A, a master substrate 9 having a plurality of substrate regions arranged in a matrix is prepared, and the crystal resonator element 2 is mounted on the substrate region of the master substrate 9.
The master substrate 9 is made of, for example, a resin material such as glass cloth base epoxy resin, polycarbonate, epoxy resin, or polyimide resin. For example, when formed of glass cloth base epoxy resin, glass yarn is knitted. A base is formed by impregnating the formed glass cloth substrate with a liquid precursor of an epoxy resin and polymerizing the precursor at a high temperature, and a metal foil such as a copper foil is pasted on the surface thereof. A predetermined wiring pattern including the external terminals 7 and the mounting pads 6 is formed by adopting a well-known photo-etching and processing into a predetermined pattern, and a thicker metal foil is attached to one main surface of the master substrate 9 And the wall part 5 is formed by pattern-processing this by the same method.
In addition, a pair of mounting pads 6 on the bottom surface of the cavity is attached and formed on the upper surface side of the substrate region, and external terminals 7 such as input / output terminals and ground terminals are attached and formed on the lower surface side.

Next, the thin film layer 4 is formed on the master substrate 9 by sputtering using silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), etc., in a wiring pattern in the substrate region and at locations other than the external terminals. Therefore, even if a resin substrate is used, it is possible to improve the hermetic sealing performance.
In the present embodiment, as shown in the schematic cross-sectional view of the crystal resonator of FIG. 2 as viewed from the side, a predetermined throw-away area is provided between the substrate areas arranged in a matrix. .

(Step B) Next, as shown in FIG. 3 (b), one crystal resonator element 2 is mounted on the bottom of the cavity of each substrate region of the obtained master substrate 9 as shown in FIG. The excitation electrode of the crystal resonator element 2 and the mounting pad 6 on the upper surface of the master substrate 9 are electrically and mechanically connected via the conductive adhesive 8.
A plurality of lids 3 corresponding to the substrate region of the master substrate 9 are placed and bonded onto the master substrate 9 so that the crystal resonator element 2 is sealed. The lid 3 is manufactured by processing a metal plate made of metal such as 42 alloy, Kovar, phosphor bronze, etc., having a thickness of 60 μm to 100 μm into a predetermined shape by a conventionally well-known sheet metal processing. The body 3 is provided with the plurality of lids 3 described above in a matrix so as to correspond to the substrate region of the master substrate 9 on a one-to-one basis. In the present embodiment, such a lid 3 is placed on the wall portion 5 formed on the master substrate 9 such that the crystal resonator element 2 in the substrate region corresponding to the inside of each cover region is disposed. After that, the lid 3 and the wall 5 are sealed and joined with a brazing material such as gold tin (Au—Sn).
The series of bonding steps described above is preferably performed in an inert gas atmosphere such as nitrogen gas or argon gas, or in a vacuum atmosphere, so that the space in which the crystal resonator element 5 is accommodated is filled with an inert gas. The quartz vibrating element 5 can be prevented from being corroded or deteriorated by oxygen, moisture in the atmosphere, etc. because it is in a vacuum.

(Step C) Finally, as shown in FIG. 3C, the master substrate 9 integrated in the step B is divided and cut along the outer periphery of each substrate region. The master substrate 9 is cut by, for example, collectively cutting from the master substrate 9 side using a dicer or the like, whereby a plurality of crystal resonators are obtained simultaneously.
When a crystal resonator is manufactured by such a process, it is not necessary to divide the container body 1 into individual pieces prior to the assembly of the crystal resonator, and the container body 1 is simultaneously cut by batch division. be able to. In addition, in this case, when the crystal unit is assembled, the master substrate 9 itself functions as a carrier, so that there is no need for complicated operations such as holding the individual pieces separated from the master substrate 9 individually. It becomes. As a result, the assembly process of the crystal unit is greatly simplified, and the productivity of the crystal unit can be remarkably improved.
In addition, even if the master substrate is formed of a resin substrate, when an insulating thin film layer is formed on the surface of the master substrate by the sputtering method in the step A, the resin substrate is improved while improving the hermetic sealing property of the resin substrate. Since cutting is performed, there is little influence on the dicer, and chipping or the like does not occur, so that the productivity can be remarkably improved.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the gist of the present invention. These cases are also included in the technical scope of the present invention. Needless to say.

  Further, in the above-described embodiment, the throw-away area is provided between the substrate areas of the master substrate 9, but the board areas are arranged close to each other without providing the throw-away area between the substrate areas of the master substrate 9. It doesn't matter if you do.

  Furthermore, in the above-described embodiment, the crystal resonator is configured by using the crystal resonator element 2 as the piezoelectric resonator element. However, other electronic components, for example, an IC element as an electronic component element mounted inside The present invention can also be applied to piezoelectric vibrators using other piezoelectric elements.

1 is a schematic side cross-sectional view of a crystal resonator (electronic component) manufactured by a manufacturing method of the present invention as viewed from the side. FIG. 3 is a schematic cross-sectional view seen from the side surface direction of the crystal unit for explaining the manufacturing method according to the embodiment of the present invention. FIGS. 3A to 3C are schematic top perspective views of a piezoelectric vibrator formed by the manufacturing method of the present invention for explaining the manufacturing method according to the embodiment of the present invention. It is a schematic side cross-sectional view of a conventional crystal unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Quartz crystal vibration element (piezoelectric vibration element)
DESCRIPTION OF SYMBOLS 3 ... Lid body 4 ... Thin film layer 5 ... Wall part 6 ... Mounting pad 7 ... External terminal 8 ... Conductive adhesive 9 ... Master substrate

Claims (4)

A piezoelectric vibration element is mounted in the internal space of the rectangular container body, and a rectangular lid body that covers the opening of the container body is disposed on the top of the side wall of the container body. In the piezoelectric vibrator that is firmly attached to the conductor pattern provided in the container and hermetically seals the piezoelectric vibration element in the container body,
A piezoelectric vibrator, wherein a substrate portion is formed of an insulating resin, a wall portion is formed of a metal member, and a thin film layer is formed on a surface of the container body. Preparing a master substrate having a plurality of substrate regions arranged in a matrix, and forming a thin film on the master substrate at a location other than the wiring pattern by a sputtering method;
A piezoelectric vibration element is mounted on each substrate region, and a lid corresponding to the substrate region on a one-to-one basis is placed on the master substrate so that the piezoelectric vibration element is sealed, and is sealed and bonded. Step B,
And a step C of simultaneously obtaining a plurality of piezoelectric vibrators by collectively cutting along the outer periphery of each substrate region of the master substrate.   3. The method of manufacturing a piezoelectric vibrator according to claim 2, wherein an inclined wall portion is formed on an outer peripheral portion of each substrate region of the master substrate.   The method for manufacturing a piezoelectric vibrator according to claim 3, wherein the wall portion is integrally formed by an etching method.

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