JP2006339896A - Method for manufacturing piezoelectric vibrator and piezoelectric vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a piezoelectric vibrator compact and thin while reducing the cost. <P>SOLUTION: The piezoelectric vibrator 10 which comprises a substrate 10, a piezoelectric element 40 mounted on the substrate, and a cover 20 having a recess 21 for sealing the piezoelectric element 40 and in which the substrate 10 and cover 20 are joined together to close the recess 21 includes the substrate 10 whose surface is flatly processed, a mounting pattern 31 for mounting the piezoelectric element formed on the substrate 10, a lead-around pattern 32 for leading the mounting pattern 31 around to the outside, an external mounting pattern 33 connecting with the lead-around pattern 32, and the piezoelectric element 40 mounted on the respective mounting patterns 31 by GGI joining, and formed by cutting the substrate 10 and cover 20 which are connected directly in states of wafers into pieces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface-mountable piezoelectric vibrator manufacturing method and a piezoelectric vibrator.

Conventionally, as a surface-mountable piezoelectric vibrator, a piezoelectric vibrator configured by sandwiching a piezoelectric substrate made of quartz, in which a frame portion and a vibrating portion are integrally formed, between a glass lid and a substrate has been proposed. (For example, refer to Patent Document 1).
In such a piezoelectric vibrator, in order not to deteriorate the vibration characteristics of the piezoelectric substrate, a concave portion is formed in the lid and the substrate so as to accommodate the vibrating portion. In addition, a metal layer is formed on both the back surface and the front surface of the frame portion of the piezoelectric substrate, and the frame portion and the lid, and the frame portion and the substrate are bonded to each other with the concave portion facing the vibration portion by anodic bonding. Yes.

In this method for manufacturing a piezoelectric vibrator, first, a lid and a substrate are diced from a wafer into individual pieces. Next, after the lid and the substrate are diced from the wafer into individual pieces, a step of integrally forming the frame portion and the vibration portion on the piezoelectric element, and a step of forming a metal layer on the back surface and the surface of the outer frame, A step of forming an electrode on the piezoelectric element, a step of forming a recess in the lid, a step of forming a recess in the substrate, a step of forming a through hole in the substrate, and one surface of the frame portion and the lid as an anode The piezoelectric vibrator is manufactured through a step of bonding the concave portion toward the vibration portion by bonding and a step of bonding the other surface of the frame portion and the substrate to the vibration portion by anodic bonding.
In general, glass frit, metal can resistance welding, seam welding, resin sealing, thermal fusion, EB sealing, and the like are known as hermetic sealing methods for vibrators and oscillators.
Japanese Patent No. 3390348 (paragraphs 0005 to 0013, FIG. 3)

However, when assembling a piezoelectric vibrator with the substrate and lid in pieces, the manufacturing equipment becomes complicated to handle each component individually due to various factors such as component accuracy, jig accuracy, and equipment accuracy. Management related to the manufacturing apparatus becomes complicated, or it becomes necessary to introduce new equipment, which causes an increase in cost.
Further, when assembling the piezoelectric vibrator with the substrate and the lid being in pieces, it is difficult to reduce the size and height of the piezoelectric vibrator because the equipment needs to grip or / and fix each component. ing.
In addition, the piezoelectric element made of quartz is not only costly to manufacture because the frame part and the vibrating part are integrally formed, but it also takes time to manufacture because it requires advanced etching technology. .
Furthermore, when anodic bonding is performed with a quartz crystal sandwiched between glass, the expansion coefficient differs between the quartz crystal and the glass, so that stress remains after bonding, and it is difficult to obtain a stable bonded state.

  Accordingly, it is an object of the present invention to provide a piezoelectric vibrator manufacturing method and a piezoelectric vibrator that solve the above-described problems, reduce costs, enable a reduction in size and height, and obtain a stable bonded state. .

  In order to solve the above problems, the present invention is composed of a substrate wafer, a piezoelectric element mounted on the substrate wafer, and a lid wafer provided with a recess for sealing the piezoelectric element in a matrix shape, A method of manufacturing a piezoelectric vibrator in which the substrate wafer and the lid wafer are bonded so as to close a recess, the substrate wafer flat processing step for flatly processing the surface of the substrate wafer, and a region bonded to the lid wafer A via hole penetrating to the back side and a groove reaching the inside of the concave portion from the via hole, and forming the piezoelectric element on the substrate wafer so as to be accommodated in the concave portion A mounting pattern, a routing pattern for routing the mounting pattern to the outside through the via hole and the groove, and an external actual connected to the routing pattern. A pattern forming step for forming a pattern, a piezoelectric element mounting step for mounting the piezoelectric element on each mounting pattern, a lid wafer flat processing step for flatly processing the bonding surface of the lid wafer, and closing the recess A piezoelectric vibration comprising: a wafer bonding step for bonding the substrate wafer and the lid wafer by direct bonding; and a singulation step for dividing the bonded substrate wafer and the lid wafer into individual pieces. It is a manufacturing method of a child.

  Thus, by using the substrate wafer in which the substrates are arranged in a matrix and the lid wafer in which the lids are arranged in a matrix, the substrate wafer and the lid wafer can be easily fixed and / or gripped. It is possible to easily form a mounting pattern for mounting the piezoelectric element on a substrate wafer, a routing pattern for routing the mounting pattern to the outside, an external mounting pattern connected to the routing pattern, and mounting the piezoelectric element. Is mounted on the substrate wafer so as to fit in the recessed area of the lid wafer, and further, the substrate wafer and the lid wafer are directly joined and then separated into individual pieces, so that a small and low-profile piezoelectric vibrator is manufactured. be able to.

Further, since the bonding between the substrate wafer and the lid wafer is a direct bonding, it is not necessary to provide an adhesive or a layer for bonding in the bonding, so that the cost can be reduced.
In addition, compared with the conventional case where the substrate and the lid are assembled in the state of individual pieces, a jig for assembling and transporting is not required, so that the cost can be reduced.
In addition, since a via hole and a groove reaching the inside of the recess from the via hole are provided, and a routing pattern is provided in the via hole and the groove, the bonding failure between the substrate wafer and the lid wafer due to the thickness of the routing pattern is prevented, and stable bonding is achieved. Can keep the state.

In the present invention, the substrate wafer and the lid wafer may be made of the same material, and the material may be any of silicon, glass, and crystal.
As described above, the substrate wafer and the lid wafer are made of the same material, and any of silicon, glass, and quartz can be used to prevent residual stress and to achieve direct bonding. it can.

In the present invention, the piezoelectric element may be bonded to each mounting pattern by GGI bonding.
Thereby, since the anodic bonding is performed between the substrate wafer and the lid wafer, the manufacturing process can be shortened, and the piezoelectric element can be easily mounted on the substrate wafer.

  The present invention also includes a substrate, a piezoelectric element mounted on the substrate, and a lid provided with a recess for sealing the piezoelectric element, and the substrate and the lid so as to close the recess. A piezoelectric vibrator to which the substrate is bonded, the substrate whose surface is processed flat and the lid, a via hole provided in a region bonded to the lid on the substrate and penetrating to the back side, and the via hole A groove provided on the substrate so as to enter the recess, a mounting pattern for mounting the piezoelectric element on the substrate wafer so as to fit in the recess, and the mounting pattern via the via hole and the groove A routing pattern to be routed, an external mounting pattern connected to the routing pattern, and the piezoelectric element mounted on each mounting pattern, and directly bonded in a wafer state A piezoelectric vibrator, wherein a said a plate cover formed by individual pieces.

In this way, in the wafer-like substrate and lid, the mounting pattern for mounting the piezoelectric element on the substrate wafer so as to be accommodated in each recess provided in the lid, and routing for routing the mounting pattern to the outside Since the pattern and the external mounting pattern connected to the routing pattern are formed on the substrate, the piezoelectric element is bonded to the substrate, and the substrate and the lid are directly bonded in the form of a wafer, the piezoelectric vibrator is made small and low-profile. Can be made.
Further, as compared with the conventional case where the substrate and the lid are assembled in the state of an individual piece, a jig for assembling and transporting is not required, so that the cost can be reduced.
In addition, since the substrate and the piezoelectric element are GGI-bonded, the bonding is easy, and since the substrate and the lid are directly bonded, it is not necessary to provide an adhesive or a layer for bonding. Can be reduced.
In addition, since a via hole and a groove reaching the inside of the recess from the via hole are provided, and a routing pattern is provided in the via hole and the groove, the bonding failure between the substrate wafer and the lid wafer due to the thickness of the routing pattern is prevented, and stable bonding is achieved. The state can be maintained.

In the present invention, the substrate wafer and the lid wafer may be made of the same material, and the material may be any of silicon, glass, and crystal.
As described above, the substrate wafer and the lid wafer are made of the same material, and any of silicon, glass, and quartz can be used to prevent residual stress and to achieve direct bonding. It can be done.

  In the present invention, the piezoelectric element may be mounted on the mounting pattern by GGI bonding. Thereby, joining of the piezoelectric element to a board | substrate can be performed easily.

According to such a method for manufacturing a piezoelectric vibrator, the cost can be reduced, the size and the height can be reduced, and the bonding state between the substrate wafer and the lid wafer can be stabilized.
Further, according to such a piezoelectric vibrator, the cost can be reduced, the size and the height can be reduced, and the bonding state between the substrate and the lid can be stabilized.

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 blank type crystal is used as the piezoelectric element will be described in the piezoelectric vibrator of the present invention.
FIG. 1 is an exploded perspective view showing an example of a state in which piezoelectric vibrators according to an embodiment of the present invention are arranged in a wafer shape. FIG. 2A is a cross-sectional view showing an example of a manufacturing state of the piezoelectric vibrator according to the embodiment of the present invention, and FIG. 2B is a cross-sectional view showing a process following FIG. 2A. FIG. 2C is an enlarged view of part C of FIG. FIG. 3 is a cross-sectional view showing a step following FIG. FIG. 4A is a cross-sectional view showing a process following FIG. 3, and FIG. 4B is a cross-sectional view showing a process following FIG. 4A. FIG. 5 is a flowchart showing an example of the manufacturing process of the piezoelectric vibrator according to the embodiment of the present invention.

As shown in FIG. 4, the piezoelectric vibrator 100 of the present invention includes a substrate 10 having a via hole 11 and a groove 12, a lid 20 having a recess 21, a piezoelectric element 40, and a substrate 10 so as to be accommodated in the recess 21. A mounting pattern 31 for mounting the piezoelectric element 40 provided on the wiring pattern 31, a routing pattern 32 for routing the mounting pattern 31 to the outside, and an external mounting pattern 33 connected to the routing pattern 32.
In addition, although the material of a board | substrate and a lid | cover is demonstrated as the same glass, silicon | silicone and quartz can also be used besides glass.

  The plurality of substrates 10 are made of glass and arranged in a matrix before being singulated, and are in a wafer (hereinafter referred to as “substrate wafer”) as a whole (see FIG. 1).

Further, the plurality of lids 20 are made of glass, and the recesses 21 are arranged in a matrix before being singulated, so that the entire lid 20 is in a wafer state (hereinafter referred to as “lid wafer”) ( (See FIG. 1).
.. Of the substrate wafer KW corresponds to the arrangement position of the lids 20, 20... Of the lid wafer FW (see FIG. 1).

The surface of the substrate wafer KW is processed flat. In this process, the surface of the substrate wafer KW is processed flatly so as to be directly bonded to the lid wafer FW (see FIG. 5, S1) (substrate wafer flat processing step).
When processing or processing the substrate wafer KW, the substrate wafer KW can be easily fixed by using, for example, a processing machine (not shown) provided with a suction type fixed bed.
Further, it is desirable that the surface treatment of the substrate wafer KW and the lid wafer FW described later is made flat by mirror polishing or the like.

As shown in FIG. 2C, the substrate wafer KW is provided with a via hole 11 at a bonding surface with the lid wafer FW, which is a portion that becomes each substrate 10, and the via hole 11 extends to the lid wafer FW. The groove 12 is provided on the substrate so as to be accommodated in the provided recess 21 (see FIG. 5, S2) (drawing path forming step).
The via hole 11 penetrates the substrate 10 in the thickness direction and is filled with a routing pattern 32 described later.

As shown in FIGS. 1 and 2A, the substrate wafer KW leaves a bonding surface for direct bonding to the lid wafer FW, that is, the substrate wafer is accommodated in the provided recess 21. A mounting pattern 31 is formed in a portion that becomes the substrate 10 of KW, and a routing pattern 32 and an external mounting pattern 33 that lead the mounting pattern 31 to the outside through the via hole 11 and the groove 12 are formed in the portion that becomes the substrate 10. (See FIG. 5, S3) (pattern formation step).
The mounting pattern 31, the routing pattern 32, and the external mounting pattern 33 are made of a conductive material, and the lead pattern 32 is provided so as to fill the via hole 11 and the groove 12 and fill the via hole 11 and the groove 12. .

  The mounting pattern 31, the routing pattern 32, and the external mounting pattern 33 are made of Au, and the mounting pattern 31 that mounts the piezoelectric element 40 is connected to the routing pattern 32 that leads the mounting pattern 31 to the outside. The external mounting pattern 33 is connected.

As shown in FIG. 2B, the piezoelectric element 40 on which the electrode 41 is formed is mounted on the mounting pattern 31 by GGI bonding (see FIG. 5, S4) (piezoelectric element mounting step).
The electrode 41 formed on the piezoelectric element 40 is Au, and is formed in a film shape on the surface of the piezoelectric element 40, and a bump B is formed on a portion mounted on the mounting pattern 31. .

  On the substrate wafer KW on which the piezoelectric elements 40 are mounted in this way, a mounting pattern 31, a routing pattern 32, and an external mounting pattern 33 are formed corresponding to the substrates 10 arranged in a matrix, respectively. A piezoelectric element 40 is mounted. Therefore, the piezoelectric elements 40 are arranged in a matrix on the substrate wafer KF.

In addition, in the lid wafer FW, concave portions 21 are formed in a matrix in each portion that becomes the lid 20.
The concave portion 21 is formed in a portion that becomes the lid 20 of the lid wafer FW to such an extent that it does not come into contact with a piezoelectric element 40 (described later) mounted on the base wafer KW (see FIG. 5, S5) (concave forming step).
When processing or transporting the lid wafer FW, the lid wafer FW can be easily fixed by using, for example, a processing machine (not shown) provided with a suction type fixing arm.

  And the surface which provided the recessed part 21 of the lid | cover wafer FW, ie, the surface joined to the substrate wafer KW, is processed flat. In this process, the surface of the lid wafer FW is flattened in order to directly bond to the substrate wafer KW (see FIG. 5, S6) (lid wafer flattening process). The lid wafer flattening process may be performed before the recess forming process.

In this state, as shown in FIGS. 3 to 4A, the substrate wafer KW and the lid wafer FW are overlapped and directly bonded so that the piezoelectric element 40 is accommodated in the recess 21 formed in the lid wafer FW. Perform (see FIG. 5, S7) (wafer bonding step).
As a result, the substrate wafer KW and the lid wafer FW are joined, and a plurality of piezoelectric vibrators 100, 100... Are arranged in a matrix.
In addition, various conditions conventionally used can be applied as they are for direct bonding.
As an example, heat treatment is performed at a temperature of 200 ° C. to 500 ° C. for a predetermined time.

  In this way, a plurality of piezoelectric vibrators 100, 100... Arranged in a matrix, that is, as shown in FIG. It divides into pieces using dicing, a laser, etc. (refer FIG. 5, S8) (single piece process). If comprised in this way, several piezoelectric vibrator 100,100 ... will be obtained at once.

Thus, by using the substrate wafer KW in which the substrates 10 are arranged in a matrix and the lid wafer FW in which the lids 20 are arranged in a matrix, the substrate wafer KW and the lid wafer FW can be fixed or / and Since the gripping can be easily performed, the mounting pattern 31, the routing pattern 32, the external mounting pattern 33, and the piezoelectric element 40 can be easily formed on the substrate wafer KW, and the piezoelectric element 40 can be recessed in the lid wafer FW. 21. Since the substrate wafer KW and the lid wafer FW are directly bonded to each other so as to fit within the substrate wafer KW, the piezoelectric vibrator 100 can be made small and low-profile.
Further, mounting of the piezoelectric element 40 on the substrate wafer KW is performed by GGI bonding (gold-gold bonding), so that the mounting of the piezoelectric element 40 is facilitated, and the bonding of the substrate wafer KW and the lid wafer FW is directly bonded. As a result, it is not necessary to provide an adhesive or a layer for bonding in the bonding, so that the cost can be reduced. Further, compared with the conventional case where the substrate 10 and the lid 20 are assembled in the state of individual pieces, a jig for assembling and transporting becomes unnecessary, so that the cost can be reduced.

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, after the piezoelectric element mounting process and before the wafer bonding process, a piezoelectric element frequency adjustment process for adjusting the frequency may be performed, or after the wafer bonding process and before the singulation process, You may perform the process of test | inspecting whether a joining state is favorable.

It is a disassembled perspective view which shows an example of the state by which the piezoelectric vibrator concerning embodiment of this invention was arranged in wafer shape. (A) is sectional drawing which shows an example of the manufacturing state of the piezoelectric vibrator concerning embodiment of this invention, (b) is sectional drawing which shows the process following (a), (c) is (a). FIG. FIG. 3 is a cross-sectional view showing a step that follows FIG. (A) is sectional drawing which shows the process of following FIG. 3, (b) is sectional drawing which shows the process of following FIG. 4 (a). 3 is a flowchart illustrating an example of a manufacturing process of a piezoelectric vibrator according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Piezoelectric vibrator 10 Substrate 11 Via hole 12 Groove 20 Lid 21 Recessed part 31 Mounting pattern 32 Leading pattern 33 External mounting pattern 40 Piezoelectric element 41 Electrode KW Substrate wafer FW Lid wafer B Bump

Claims (6)

A substrate wafer, a piezoelectric element mounted on the substrate wafer, and a lid wafer in which concave portions for sealing the piezoelectric elements are provided in a matrix, and the substrate wafer and the lid so as to close the concave portion A method of manufacturing a piezoelectric vibrator bonded to a wafer,
A substrate wafer flat processing step for flatly processing the surface of the substrate wafer;
A lead-out path forming step in which a via hole penetrating to the back side provided in a region bonded to the lid wafer and a groove reaching the inside of the concave portion from the via hole are formed in the substrate wafer;
A mounting pattern for mounting the piezoelectric element on the substrate wafer so as to fit in the recesses, a routing pattern for routing the mounting pattern to the outside via the via hole and the groove, and an external mounting pattern for connecting to the routing pattern are formed. Pattern forming process,
A piezoelectric element mounting step of mounting the piezoelectric element on each mounting pattern;
A lid wafer flat processing step for flatly processing the bonding surface of the lid wafer;
A wafer bonding step of bonding the substrate wafer and the lid wafer by direct bonding so as to close the concave portion;
A process for dividing the bonded substrate wafer and the lid wafer into individual pieces,
A method of manufacturing a piezoelectric vibrator. 2. The method of manufacturing a piezoelectric vibrator according to claim 1, wherein the substrate wafer and the lid wafer are made of the same material, and the material is any one of silicon, glass, and quartz. 3. The method of manufacturing a piezoelectric vibrator according to claim 1, wherein the piezoelectric element is mounted on each mounting pattern by GGI bonding. A piezoelectric device comprising a substrate, a piezoelectric element mounted on the substrate, and a lid provided with a recess for sealing the piezoelectric element, and the substrate and the lid are joined so as to close the recess. A vibrator,
The substrate whose surface has been treated flat and the lid;
A via hole that is provided in a region bonded to the lid on the substrate and penetrates to the back side;
A groove provided on the substrate so as to enter the recess from the via hole;
A mounting pattern for mounting the piezoelectric element on the substrate wafer so as to be accommodated in the recesses, a routing pattern for routing the mounting pattern to the outside via the via hole and the groove, and an external mounting pattern connected to the routing pattern When,
The piezoelectric elements mounted on the mounting patterns;
With
A piezoelectric vibrator characterized in that the substrate and the lid that are directly bonded in a wafer state are separated into pieces. The piezoelectric vibrator according to claim 4, wherein the substrate wafer and the lid wafer are made of the same material, and the material is any one of silicon, glass, and quartz. The piezoelectric vibrator according to claim 4, wherein the piezoelectric element is mounted on the mounting pattern by GGI bonding.

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