JP5171210B2 - Method for manufacturing piezoelectric vibrator - Google Patents

Description

  The present invention relates to a method for manufacturing a piezoelectric vibrator used in an electronic device.

Conventionally, as a surface-mountable piezoelectric vibrator used for electronic equipment, for example, a crystal vibrator has been used. As this crystal resonator, one having a structure in which a quartz resonator element is mounted on a substrate body and hermetically sealed with a lid provided with a recess has been proposed (for example, see Patent Document 1). In this method of manufacturing a crystal resonator, a bonding metal film and a wiring pattern are provided on a substrate body, a crystal resonator element is mounted on the substrate body, and the lid body is placed on the substrate so that the crystal resonator element is placed in the recess. A quartz crystal unit is manufactured by performing anodic bonding in contact with the body.
At the time of bonding, for example, if anodic bonding is performed in a vacuum, the inside of the recess is hermetically sealed in a vacuum state.

Here, the wiring pattern provided on the surface of one main surface of the substrate body is in a state of being electrically connected to an external electrode provided on the back surface side through a through hole provided in the substrate body. .
More specifically, for example, after forming a substrate body through hole, electroless plating is performed to form a metal film. On the surface, a resist is applied, exposed and developed to determine the shape of the wiring pattern. In this state, the through hole is filled, unnecessary plating is removed, and the resist is also removed. This completes the wiring pattern. Thereafter, in order to form a metal film for bonding, a resist is applied to the substrate body, and exposure and development are performed. Then, a metal film is formed and the resist is removed. Thus, the substrate body was formed.

Such a crystal resonator is manufactured in a wafer state in which a plurality of substrate bodies or lid bodies are arranged in a matrix. Accordingly, one crystal vibration element is mounted on each of the substrate bodies arranged one by one in a wafer state. When mounting of the crystal resonator elements on all the substrate bodies is completed, a plurality of lid bodies arranged in a wafer state are brought into contact with the substrate body in the wafer state, and the lid body and the substrate body in the wafer state are bonded by anodic bonding. Join.
Thereafter, a plurality of crystal resonators are obtained by cutting or cleaving between adjacent substrate bodies or between adjacent lid bodies.

JP2007-013628

However, in response to market demands for miniaturization of piezoelectric vibrators, the gap between the bonding metal film and the wiring pattern is narrowed, so that accuracy is required when forming the bonding metal film and the wiring pattern. Desired. For this reason, a resist must be applied to a precise position of the substrate body to form a mask, and it is becoming difficult to form a bonding metal film and a wiring pattern.
In addition, it is necessary to fill the through hole provided in the substrate body with a conductive material in order to ensure hermetic sealing. However, although there is concern about the generation of dust in this process, the process is complicated in order to prevent the adhesion of dust and the like to the bonding metal film.

  Accordingly, an object of the present invention is to provide a method of manufacturing a piezoelectric vibrator that solves the above-described problems, can be reduced in size, and can be easily manufactured.

In order to solve the above-described problems, the present invention provides a lid body having a concave portion in which a piezoelectric vibration element is mounted on a flat substrate body having a wiring pattern on one main surface and an external terminal on the other main surface. A method of manufacturing a piezoelectric vibrator in which the piezoelectric vibration element is hermetically sealed in the recess by bonding to the substrate body, and a through hole forming step of providing a through hole at a position corresponding to the wiring pattern of the substrate body A pattern forming step of forming the wiring pattern and the external terminal on the substrate body and filling the through hole with a conductive material; and a piezoelectric vibration element mounting step of mounting the piezoelectric vibration element on the wiring pattern; and bonding metal film forming step of providing a bonding metal layer on the surface of the frame portion facing the bottom surface in the same direction of the recess and the recess in the lid to have a concave portion by a flat plate portion and the frame portion, before Ri Do and a bonding step of bonding the cover member and the substrate member by anodic bonding by contacting the lid to the substrate body, the bonding metal layer forming step, the piezoelectric vibrating element mounted from the through-hole forming step A method of manufacturing a piezoelectric vibrator, which is performed simultaneously with or before any of the steps up to the step .

  In the present invention, the substrate bodies are arranged in a matrix to form a wafer, and the lid bodies are arranged in a matrix to form a wafer. The wafer-shaped substrate and the substrate The wafer-shaped lid may be bonded together in a wafer shape.

  Further, the present invention is characterized in that the bonding metal film is Al (aluminum).

  According to such a method for manufacturing a piezoelectric vibrator, only the wiring pattern is provided on the substrate body without providing the bonding metal film, and the entire surface in the concave portion of the lid body and the bottom surface of the concave portion of the frame portion forming the concave portion are the same. Since the bonding metal film is provided on the surface that faces the direction, even if the piezoelectric vibrator is downsized, there is no need for precision in the formation of the wiring pattern, and the manufacture of the piezoelectric vibrator can be facilitated.

Further, since the bonding metal film provided on the lid can be provided without using a mask such as a resist, the work of accurately providing the mask is omitted, and the workability can be improved.
In addition, the bonding metal film forming process for providing the bonding metal film on the lid body is performed simultaneously with or before any one of the processes from the through-hole forming process to the piezoelectric vibration element mounting process. The bonding metal film forming step can prevent dust from adhering to the bonding metal film regardless of the formation of the wiring pattern or the like on the substrate body.

  In addition, since the substrate body and the lid body are bonded in the state of a wafer, a plurality of piezoelectric vibrators can be formed at a time.

  Further, since the bonding metal film is made of Al (aluminum), it is possible to easily bond the substrate body and the lid body.

Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. The case where a rectangular crystal is used as the piezoelectric element will be described in the piezoelectric vibrator of the present invention.
FIG. 1 is a perspective view showing a state before mounting and joining. 2A is a conceptual diagram illustrating an example of a wafer-like substrate body, and FIG. 2B is a conceptual diagram illustrating a state in which a through hole is provided at a position serving as a substrate body. (C) is a conceptual diagram showing a state in which a wiring pattern and external terminals are provided at a position to be a substrate body, and (d) is a conceptual diagram showing a state in which a piezoelectric vibration element is mounted on the wiring pattern. FIG. 3 is a cross-sectional view corresponding to the position of the AA cross section of FIG. 1, (a) is a conceptual diagram showing an example of a wafer-like lid, and (b) is provided with a recess at a position to be a lid. It is a conceptual diagram which shows a state, (c) is a conceptual diagram which shows the state which provided the metal film for joining in the surface in which the recessed part was formed. 4A is a conceptual diagram illustrating a state before the substrate body and the lid body are joined, and FIG. 4B is a conceptual diagram illustrating a state in which the substrate body and the lid body are joined. FIG. 5 is a cross-sectional view showing an example of a piezoelectric vibration element.

  As shown in FIGS. 1 and 5, the piezoelectric vibrator 100 manufactured by the method for manufacturing a piezoelectric vibrator of the present invention is mainly composed of a substrate body 10, a piezoelectric vibration element 20, and a lid body 30.

The substrate body 10 is made of, for example, glass, and as shown in FIG. 1, the substrate body 10 is a flat plate having a rectangular shape in plan view. A wiring pattern 11 is provided on one main surface, and the other main surface is provided with a wiring pattern 11. External terminals 12 are provided at four corners of the rectangular shape.
The wiring pattern 11 includes two pairs of mounting portions 11 </ b> A for mounting the piezoelectric vibration element 20 and a routing portion 11 </ b> B for connecting to a predetermined external terminal 12.
One end of the routing portion 11B is connected to one mounting portion 11A, and the other end is electrically connected to one predetermined external terminal 12 through a through hole 13 provided in the substrate body 10. doing.
The other mounting portion 11A is connected to an external terminal 12 different from the external terminal 12 connected to the routing portion 11B through another through hole 13 provided in the substrate body 10. .

In the piezoelectric vibration element 20, for example, excitation electrodes 22 are provided on both main surfaces of a crystal piece 21 having a rectangular shape in plan view, which is a piezoelectric piece, and the crystal piece 21 is formed from the excitation electrodes 22 provided on the respective main surfaces. A routing pattern 23 is formed extending toward the end portion side (see FIG. 1).
The piezoelectric vibration element 20 is bonded to the lead pattern 23 connected to the excitation electrode 22 and the mounting portion 11A of the wiring pattern 11 provided on the substrate body 10 by the conductive adhesive D.
Thereby, the piezoelectric vibration element 20 is mounted on the substrate body 10.

As shown in FIGS. 1 and 5, the lid 30 has a concave portion 33 formed of a flat plate portion 31 and a frame portion 32, and the frame portion 32 faces the same direction as the entire surface in the concave portion and the bottom surface of the concave portion 33. A metal film for bonding 34 is provided on the surface of this.
The bonding metal film 34 is made of Al (aluminum) and is used when the substrate body 10 and the lid body 20 are bonded.
The lid is made of glass, for example.

  In such a piezoelectric vibrator 100, the bonding metal film 34 is provided on the lid body 30, and the bonding metal film other than the wiring pattern 11 and the external terminal 12 is not provided on the substrate body 10. The bonding metal film and the wiring pattern 11 are not short-circuited, and the wiring pattern 11 can be easily formed even when the size is reduced. In addition, since the bonding metal film 34 is provided on the entire surface in the concave portion of the lid 30 and the surface of the frame portion 32 facing the same direction as the bottom surface of the concave portion 33, a conventional pattern for bonding is provided. There is no need to form the substrate body 10, and the bonding metal film 34 can be easily provided on the lid body 30.

Next, a method for manufacturing a piezoelectric vibration element according to an embodiment of the present invention will be described.
In the following description, it is assumed that the piezoelectric vibration element 20 is in a state in which the excitation electrode 22 and the lead pattern 23 are formed in advance on a crystal piece 21 that is a piezoelectric piece.

First, as shown in FIGS. 2A to 2B, a plurality of through holes 13 are provided at a predetermined interval on a plate-like wafer having a larger area than the substrate body 10 (through hole forming step). At this time, the through holes 13 are arranged in a matrix with two pairs.
A copper film is formed on the entire surface of the wafer by using an electroless plating method or a conventionally known sputtering.
Then, a resist is applied to the wafer so as to have the shape of the wiring pattern 11, and exposure and development are performed. At this time, the through hole 13 is located in the wiring pattern 11.
Then, the through hole 13 is filled with copper and connected to the wiring pattern 11.
Unnecessary plated copper is removed and the resist is removed to form a wiring pattern 11 (see FIG. 2C) (pattern formation step).

In the pattern forming step, a pair of four external terminals 12 may be provided on the surface opposite to the surface on which the wiring pattern 11 of the wafer is provided, or the external terminals 12 may be provided in a separate step. Of these four external terminals 12, two external terminals 12 each have one through hole 13 positioned therein. Therefore, by filling the through hole 13 with copper, the wiring pattern 11 and the external terminal 12 are electrically connected via the through hole 13.
A region surrounding the four external terminals 12 is a substrate body 10. In this state, a plurality of substrate bodies 10 are arranged in a matrix to form a wafer.

  As shown in FIG. 2D, the piezoelectric vibration element 20 is mounted on each wiring pattern 11 of the plurality of substrate bodies 10 in a wafer shape with a conductive adhesive (piezoelectric vibration element mounting step).

As shown in FIGS. 3A to 3B, a plurality of recesses 33 are provided at a predetermined interval on a plate-like wafer having a larger area than the lid 30. At this time, the recesses 33 are arranged in a matrix.
The recess 33 can be formed, for example, by applying a resist to a predetermined region of the wafer and immersing it in an etchant.

As shown in FIG. 3C, a bonding metal film 34 is formed on the surface of the wafer where the recess 33 is formed and in the recess 33 (bonding metal film forming step).
Thus, the wafer provided with the bonding metal film 34 is in a state in which a plurality of lids 30 are formed with the boundary between adjacent recesses 33 as a boundary. In this state, a plurality of lids 30 are arranged in a matrix to form a wafer.

This bonding metal film forming step may be performed simultaneously with or before any of the steps up to the through hole forming step, the pattern forming step, and the piezoelectric vibration element mounting step.
As a result, the bonding metal film forming step is performed at a different location for any of the through hole forming step, the pattern forming step, and the piezoelectric vibration element mounting step. In particular, the bonding metal film forming step is performed on the substrate body. Regardless of the formation of the wiring pattern or the like, it is possible to prevent dust from adhering to the bonding metal film.

As shown in FIGS. 4A to 4B, a plurality of wafer-shaped substrates 20 are mounted in the recesses 33 on the plurality of wafer-shaped substrate bodies 10 on which the piezoelectric vibration elements 20 are mounted. The lid 30 is stacked and the bonding metal film 34 is brought into contact with the substrate body 10.
In this state, a predetermined voltage is applied to perform anodic bonding, and the wafer-shaped substrate body and the wafer-shaped lid body are bonded together in a wafer shape.

When the joining is completed, a plurality of piezoelectric vibrators 100 are arranged in a matrix.
In this state, for example, the individual piezoelectric vibrators 100 can be formed by cutting or cleaving between the adjacent recesses 33 (see FIG. 5).

As described above, according to the method of manufacturing a piezoelectric vibrator according to the embodiment of the present invention, the wiring pattern 11 is provided on the substrate body 10 and the bonding metal film 34 is provided on the lid body 30. Even if the size is reduced, the precision of the formation of the wiring pattern 11 is eliminated, and the manufacture of the piezoelectric vibrator 100 can be facilitated.
Further, since the bonding metal film 34 provided on the lid 30 can be provided without using a mask such as a resist, the work of accurately providing the mask is omitted, and the workability can be improved.

Further, the bonding metal film forming process for providing the bonding metal film 34 on the lid 30 is performed at the same time as or before any of the processes from the through hole forming process, the pattern forming process, and the piezoelectric vibration element mounting process. In addition, the bonding metal film forming process is performed at a different location for any of the through hole forming process, the pattern forming process, and the piezoelectric vibration element mounting process, thereby preventing dust from adhering to the bonding metal film 34. Can do.
In addition, since the substrate body 10 and the lid body 30 are bonded in the state of a wafer, a plurality of piezoelectric vibrators 100 can be formed at a time.
Further, since the bonding metal film 34 is made of Al (aluminum), the substrate body 10 and the lid body 30 can be easily bonded.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, ceramic or the like can be used as the piezoelectric element. Further, the piezoelectric vibration element may have a tuning fork shape.
Further, in the piezoelectric vibrator having such a structure, since the bonding metal film 34 is provided on the entire surface of the recess 33 of the lid 30, printing can be performed on the bonding metal film 34 by external laser irradiation. I can do it.
The external terminals may be provided at two locations so as to face each other in addition to the four corners of the substrate body 10.

It is a perspective view which shows the state before mounting and joining. 1A is a conceptual diagram illustrating an example of a wafer-like substrate body, and FIG. 1B is a conceptual diagram illustrating a state in which a through hole is provided at a position to be a substrate body. (C) is a conceptual diagram which shows the state which provided the wiring pattern and the external terminal in the position used as a board | substrate body, (d) is a conceptual diagram which shows the state which mounted the piezoelectric vibration element in the wiring pattern. In the cross section corresponding to the position of the AA cross section of FIG. 1, (a) is a conceptual diagram which shows an example of a wafer-like cover body, (b) is the state which provided the recessed part in the position used as a cover body. It is a conceptual diagram to show, (c) is a conceptual diagram which shows the state which provided the metal film for joining in the surface in which the recessed part was formed. (A) is a conceptual diagram which shows the state before joining a board | substrate body and a cover body, (b) is a conceptual diagram which shows the state which joined the board body and the cover body. It is sectional drawing which shows an example of a piezoelectric vibration element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Piezoelectric vibrator 10 Substrate body 11 Wiring pattern 12 External terminal 13 Through hole 20 Piezoelectric vibration element 21 Crystal piece (piezoelectric piece)
22 Excitation Electrode 23 Leading Pattern 30 Lid 31 Flat Plate 32 Frame 33 Recess 34 Bonding Metal Film

Claims (3)

A piezoelectric vibration element is mounted on a flat substrate body provided with a wiring pattern on one main surface and an external terminal is provided on the other main surface, and a lid body having a recess is joined to the substrate body. Is a method of manufacturing a piezoelectric vibrator hermetically sealed in the recess,
A through hole forming step of providing a through hole at a position corresponding to the wiring pattern of the substrate body;
Forming the wiring pattern and the external terminal on the substrate body, and filling the through hole with a conductive material;
A piezoelectric vibration element mounting step of mounting the piezoelectric vibration element on the wiring pattern;
And bonding metal film forming step of providing a bonding metal layer on the surface of the frame portion facing the bottom surface in the same direction of the recess and the recess in the lid to have the said recess by a plate portion and a frame portion,
Ri Do and a bonding step of bonding the cover member and the substrate member by anodic bonding by contacting the lid to the substrate body,
The method for manufacturing a piezoelectric vibrator, wherein the bonding metal film forming step is performed simultaneously with or before any of the steps from the through hole forming step to the piezoelectric vibrating element mounting step . The substrate bodies are arranged in a matrix to form a wafer, and the lid bodies are arranged in a matrix to form a wafer, and the wafer-shaped substrate body and the wafer-shaped lid method for manufacturing a piezoelectric vibrator according to claim 1 but characterized by Rukoto joined together in the wafer form. Method for manufacturing a piezoelectric vibrator according to claim 1 or claim 2 wherein the bonding metal film is characterized in Al (aluminum) der Rukoto.

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