JP5353758B2 - Manufacturing method of vibratory gyroscope - Google Patents

Description

  The present invention relates to a piezoelectric vibrating piece, a method of manufacturing a piezoelectric vibrating piece, a piezoelectric vibrator and a vibrating gyroscope, a piezoelectric vibrator, and a manufacturing method of a vibrating gyroscope.

Conventionally, there has been known a piezoelectric vibrating piece that obtains a predetermined resonance frequency by applying a driving current through an excitation electrode formed on the surface of a thin plate piece made of a piezoelectric material such as quartz.
In this piezoelectric vibrating piece, first, a thin wafer made of a piezoelectric material is formed, a plurality of piezoelectric vibrating pieces are simultaneously formed from the wafer by photolithography, and a connecting portion connecting the piezoelectric vibrating piece and the wafer is connected to the piezoelectric vibrating piece. It was formed by a manufacturing method in which the piezoelectric vibrating piece was separated from the wafer by folding after forming the outer shape.
When the connecting portion connecting the piezoelectric vibrating piece and the wafer is folded, a separation portion is formed by forming a part of the connecting portion to be thin.
As a result, the separation portion becomes a structurally weak portion, and it is known that the piezoelectric vibrating piece can be easily detached at this portion. (For example, refer to Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-91866 (page 7, FIG. 6)

In such a patent document 1, when the connecting portion that connects the piezoelectric vibrating piece and the wafer is folded, a part of the connecting portion is formed thin, so that a separating portion is formed. Since it is a structurally weak part, it can be easily separated at this part.
However, it is difficult to balance the thinly formed portion of the connecting part with the force at the time of separation and the holding force to prevent the piezoelectric vibrating piece from falling off from the wafer during the manufacturing process. In some cases, separation is not possible at a predetermined position, and when separating, it is predicted that a separation part is easily formed in a shell shape from the separation part to the surface of the piezoelectric vibrating piece. Among them, there is a problem that the piezoelectric vibrating piece falls off from the wafer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a piezoelectric vibrating piece that is small in size, has good mass productivity, and obtains a stable resonance frequency, a method for manufacturing the piezoelectric vibrating piece, a piezoelectric vibrator and a vibrating gyroscope including the piezoelectric vibrating piece, and the piezoelectric And a method of manufacturing a piezoelectric vibrator and a vibrating gyroscope including the vibrating piece.

The piezoelectric vibrating piece according to the present invention is a piezoelectric vibrating piece formed by photolithography from a wafer made of a piezoelectric material, and a frame of the wafer formed around a part of the piezoelectric vibrating piece and around the piezoelectric vibrating piece. A plate-like connecting portion is formed, and a recess having a substantially V-shaped cross-section is formed in a straight line in the width direction of the connecting portion on at least one surface of the connecting portion. It is characterized by.
Here, a piezoelectric single crystal made of quartz, LiNbO ₃ , LiTaO ₃ , a lithium niobate solid solution single crystal, a lithium borate single crystal, a langasite single crystal, or the like can be used as the substrate of the piezoelectric vibrating piece.

According to the present invention, the piezoelectric vibrating piece is formed from the wafer by photolithography. One or a plurality of such piezoelectric vibrating pieces are formed at the same time, and the piezoelectric vibrating pieces are used separately from the wafer. At this time, a concave portion having a substantially V-shaped cross section is formed in the connecting portion between the frame portion of the wafer and the piezoelectric vibrating piece.
Here, the substantially V-shaped cross section means that, for example, the opening of the recess is wide and the bottom is narrow, and the V-shaped, U-shaped, and the shape having a flat portion at the bottom are also included. included.
In addition, one or a plurality of the recesses may be formed continuously, and the recess is formed to be structurally weaker than the other parts of the connection portion, so that an external force is applied to the connection portion. When added, the stress concentrates in the recess, so that the piezoelectric vibrating piece can be easily separated from the wafer and taken out as will be described later.

For example, if the base material of the piezoelectric vibrating piece is quartz, it has a hard and brittle nature, so it can be easily folded along the recess by supporting the frame part and pushing down the approximate center part of the piezoelectric vibrating piece. The vibrating piece can be separated. This can increase the production efficiency of the piezoelectric vibrating piece.
Further, since the recess has a substantially V-shaped cross section, it is folded away from the vicinity of the tip of the bottom, so that an accurate outer shape can be obtained with little variation in the position of the breakaway portion. As a result, there is an effect that a stable resonance frequency can be obtained.

  Further, it is preferable that the connecting portion is formed so as to protrude from a support portion that connects the vibrating arms of the piezoelectric vibrating piece, and the concave portion is formed in the connecting portion, and is formed by being separated by the concave portion. .

  When the above-described piezoelectric vibrating piece is, for example, a tuning fork type vibrating piece, the pair of vibrating arms are connected by a support portion at one end that has little influence on vibration. Further, in the double T-type vibrating piece, when the piezoelectric vibrating piece is folded, for example, by connecting the vibrating arm to each other, for example, by providing a connecting portion between the support portion of the connecting arm and the frame portion of the wafer. Even if there is a slight variation in the shape of the separating portion, there is an effect that the resonance frequency is hardly affected.

  Further, in the above-described structure, it is preferable that a part of the connecting part is formed with a constricted part whose width is narrower than that of the other part, and the concave part is formed in the constricted part.

  According to such a structure, the constricted portion is formed in the connecting portion of the frame portion between the piezoelectric vibrating piece and the wafer, and the concave portion is formed near the narrowest portion of the constricted portion. When folding, stress concentration easily occurs, and it can be folded even with a small force. As a result, the production efficiency is improved, the variation in the position and shape of the separation portion of the piezoelectric vibrating piece can be reduced, and the resonance frequency is hardly affected.

  Moreover, it is preferable that the said recessed part is provided in one surface of the said connection part, or both of one surface and the other surface, and it is formed by being folded in the said recessed part.

  Since the piezoelectric vibrating piece formed in this way has recesses formed on both the front and back surfaces of the connecting portion, the piezoelectric vibrating piece can be more easily separated, thereby reducing the variation in the shape of the separating portion.

  In the above-described structure, the recess formed in one surface of the connecting portion and the recess formed in the other surface are provided at the same position in the plane direction and at the same depth. It is preferable to be formed by being folded at the recess.

  Since the aforementioned recesses are formed at the same position from the front and back of the connecting portion, the bottom portion of the recess has a small remaining thickness even if the size (depth) of each recess is small. The vibrating piece can be easily separated.

  Furthermore, the recesses drilled in one surface of the connecting portion and the recesses drilled in the other surface are alternately provided in the same direction, and are formed by being folded along the recess. It is preferable.

  In this way, since the bottoms of the recesses provided on the front and back surfaces of the connecting portion are alternately formed so as not to overlap in the connecting portion width direction, the recesses are continuous in the width direction of the connecting portion. As a result, the piezoelectric vibrating piece can be easily separated from the wafer, and the separation portion is formed linearly, so that a stable resonance frequency can be obtained.

  One of the recess formed in one surface of the connecting portion and the recess formed in the other surface is formed deeper than the other recess, and is folded along the recess. It is preferable that they are formed apart.

  Such a piezoelectric vibrating piece is folded away from the recess by, for example, pushing down the support portion with a jig or the like from one surface to the other surface (back surface). In such a case, if the concave portion on the pressing side is formed deep and the concave portion on the opposite side is formed shallow, it is possible to reduce peeling of the piezoelectric vibrating piece in the shape of a shell when being separated.

  In the piezoelectric vibrating piece according to the present invention, the concave portion formed on one surface of the connecting portion and the concave portion formed on the other surface are provided substantially in parallel with each other at a position shifted in a plane direction. It is preferable.

  In such a structure, since the concave portion provided on the front surface and the concave portion provided on the back surface are shifted, it will be described in detail later, it is prevented from separating and falling off during the manufacturing process of the piezoelectric vibrating piece, In addition, it can be easily separated at the time of folding.

  In addition, the piezoelectric vibrating piece having the above-described structure is formed on the one surface of the connecting portion, and on the other surface of the connecting portion, along the recess, across the width direction of the connecting portion. It is preferable that the groove portion is provided and is formed by being folded along the concave portion and the groove portion.

According to such a structure, when the concave portion on one surface and the groove portion on the other surface are formed, when the piezoelectric vibrating piece is folded, it is linearly folded along the concave portion and the groove, There are few unevenness | corrugations of a isolation | separation part cross section, and the influence on the vibration of a piezoelectric vibrating piece by isolation | separation part shape can be decreased.
In addition, since the portion where the concave portion is not formed is left on the surface where the concave portion is formed, the piezoelectric vibrating piece can be prevented from falling off during the process, although it can be easily separated.

  Further, the piezoelectric vibrating piece includes a constricted portion formed narrower than the other portions in at least two places, the vicinity of the support portion and the vicinity of the frame portion, and the constricted portion described above. It is desirable that a recess or a groove is formed, and that the recess is formed along the recess or the groove.

  Such a piezoelectric vibrating piece is provided with a constricted portion at a coupling portion between the frame portion of the wafer and the frame portion of the coupling portion where the piezoelectric vibrating piece is coupled, and a coupling portion with the support portion, and the constricted portion has a concave portion. Or the groove part is formed. In such a configuration, for example, first, the frame portion side can be folded away, and then the support portion side can be folded, so when one of the connecting portions is not restricted when the support portion side is folded, Since the piezoelectric vibrating piece can be folded with a small force, the productivity can be further improved.

  The method for manufacturing a piezoelectric vibrating piece according to the present invention includes a plate for connecting a part of a piezoelectric vibrating piece formed by photolithography from a wafer made of a piezoelectric material and a frame portion of the wafer formed around the piezoelectric vibrating piece. A concave portion having a substantially V-shaped cross section is formed in a straight line in the width direction of the coupling portion on at least one surface of the coupling portion, and the outer shape of the piezoelectric vibrating piece and the The recess is formed by the same etching process.

This piezoelectric vibrating piece is formed by photolithography. In general, photolithography includes a process of forming a resist film after forming a corrosion-resistant film on the surface of a wafer, and exposing, developing, and etching. In this case, the concave portion can be formed in the exposure step by using an exposure mask having an opening set smaller than the outer shape portion of the piezoelectric vibrating reed, so as not to penetrate at the same time as forming the outer shape.
For example, the size of the opening is set so that the depth of the recess is about 1/3 of the thickness of the wafer.
Thus, since the outer shape formation and the concave portion formation can be performed in the same process, the production efficiency can be increased.

  Moreover, it is preferable that the piezoelectric vibrating piece is formed by folding the piezoelectric vibrating piece and the frame portion at the concave portion.

  As described above, the recess is structurally weaker than other portions of the connecting portion. Moreover, although it is known that a piezoelectric material is hard and fragile, it can be easily separated when an external force is applied to the recess. Therefore, the piezoelectric vibrating reed can be easily detached from the wafer without using a special blade or tool, so that the production efficiency can be increased.

  The piezoelectric vibrator and the vibratory gyroscope according to the present invention are characterized in that the piezoelectric vibrating piece manufactured by the above-described structure and method is stored in a package.

  The piezoelectric vibrating piece made by the structure and the manufacturing method as described above is housed in, for example, a ceramic package or a metal cylindrical package, so that it is affected by the environment outside the package such as dust and humidity. Therefore, stable vibration can be continued for a long period of time.

  The method for manufacturing a vibrating gyroscope according to the present invention includes forming a stud bump by ultrasonic welding on at least one of the piezoelectric vibrating piece and the driving electrode and the detecting electrode formed on the piezoelectric vibrating piece. The ultrasonic vibration direction and the continuous direction of the recess are made to coincide with each other.

Here, the ultrasonic welding method uses a resonator called a horn, concentrates vibration energy to the welded part via the object to be welded, and the vibration energy is converted into frictional heat, which melts the object to be welded. To indicate that the object to be welded is fixed to a desired member.
The stud bump is a bump formed by making a ball with a gold wire and cutting the tip.

In the present invention, the connection between the piezoelectric vibrating piece and, for example, a circuit board that supports the piezoelectric vibrating piece is made by a stud bump formed on the piezoelectric vibrating piece. An ultrasonic welding method is employed to form the stud bump. By matching the vibration direction of the ultrasonic wave (horn) with the continuous direction of the concave portion, the frame portion and the vibration are generated when the stud bump is formed. It is possible to prevent the piezoelectric vibrating piece from being folded off and to be dropped off. Further, when the piezoelectric vibrating piece is detached, the piezoelectric vibrating piece can be easily detached from the concave portion, and the working efficiency can be improved. is there.
That is, according to the present invention, in a method for manufacturing a vibrating gyroscope including a piezoelectric vibrating piece formed by photolithography from a wafer made of a piezoelectric material, a part of the piezoelectric vibrating piece is formed by a plate-like connecting portion. It is connected to the frame portion of the wafer formed around the piezoelectric vibrating piece, and at least one surface of the connecting portion is continuously drilled in the width direction of the connecting portion. A stud bump is formed by ultrasonic welding on at least one of the drive electrode and the detection electrode formed on the piezoelectric vibrating piece, and the direction of ultrasonic vibration and the direction in which the recesses are made to coincide with each other. It is characterized by.
Moreover, the cross-sectional shape of the recess may be a quadrangle, and the opposing angle may coincide with a straight line connecting the constricted portions in the width direction.
Further, a plurality of concave portions may be continuous, and the planar shape of the opening may be an elongated elliptical shape.

1 is a perspective view showing a wafer according to Embodiment 1 of the present invention. 1 is a plan view showing a piezoelectric vibrating piece according to Embodiment 1 of the present invention. FIG. 3 is an enlarged plan view of a main part showing the piezoelectric vibrating piece according to the first embodiment of the invention. Sectional drawing which shows the recessed part of the piezoelectric vibrating piece which concerns on Example 1 of this invention. Sectional drawing which shows the other recessed part of the piezoelectric vibrating piece which concerns on Example 1 of this invention. Sectional drawing which shows the other recessed part of the piezoelectric vibrating piece which concerns on Example 1 of this invention. Sectional drawing which shows the other recessed part of the piezoelectric vibrating piece which concerns on Example 1 of this invention. (A) is a top view which shows the other recessed part of the piezoelectric vibrating piece which concerns on Example 1 of this invention, (b) is the sectional drawing. FIG. 6 is a plan view showing another concave portion and a groove portion of the piezoelectric vibrating piece according to the first embodiment of the invention. Sectional drawing which shows the other recessed part and groove part of the piezoelectric vibrating piece which concern on Example 1 of this invention. The top view which shows the piezoelectric vibrating piece which concerns on the other Example of this invention. FIG. 3 is a partial plan view showing a connecting portion of a piezoelectric vibrating piece according to Embodiment 1 of the present invention. FIG. 6 is a partial plan view showing another connecting portion of the piezoelectric vibrating piece according to the first embodiment of the invention. 1 is a plan view showing a tuning-fork type piezoelectric vibrating piece according to Embodiment 1 of the present invention. Sectional drawing which shows the principal part which shows the manufacturing process of the piezoelectric vibrating piece which concerns on Example 1 of this invention. FIG. 2 is a partial plan view of a grooved piezoelectric vibrating piece according to the first embodiment of the present invention. Sectional drawing which shows the principal part which shows the manufacturing process of the piezoelectric vibrating piece with a groove | channel which concerns on Example 1 of this invention. FIG. 3 is a partial plan view showing a separated state of the piezoelectric vibrating piece according to the first embodiment of the invention. FIG. 3 is a partial cross-sectional view illustrating a separated state of the piezoelectric vibrating piece according to the first embodiment of the invention. FIG. 6 is a partial cross-sectional view illustrating another separated state of the piezoelectric vibrating piece according to the first embodiment of the invention. 1 is a cross-sectional view showing a vibrating gyroscope according to Embodiment 1 of the present invention. 1 is a cross-sectional view illustrating a piezoelectric vibrator according to a first embodiment of the invention. Sectional drawing which shows the stud bump formation process which concerns on Example 1 of this invention. The top view which shows a part of stud bump formation process which concerns on Example 1 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 14 and FIG. 16 are a plan view, a cross-sectional view, and a perspective view of the piezoelectric vibrating piece of the present embodiment, and FIGS. A method is shown, and FIGS. 21 and 22 show a vibrating gyroscope and a piezoelectric vibrator. 23 and 24 show the manufacturing process of the piezoelectric vibrator and the vibration type gyroscope.

FIG. 1 is a perspective view of the wafer 1 according to the first embodiment, FIG. 2 is a plan view of the piezoelectric vibrating piece 100, and FIG. 3 is an enlarged plan view of the main part of the piezoelectric vibrating piece 100 of FIG. In FIG. 1, a wafer 1 is cut in a plane direction along an X axis called an electric axis of a general quartz crystal (not shown), a Y axis called a mechanical axis, and an X axis and a Y axis called an optical axis in a plane direction. Z-cut quartz substrate.
A piezoelectric vibrating piece 100 is formed on the wafer 1 by photolithography.

  In FIG. 2, a plurality of piezoelectric vibrating reeds 100 are simultaneously formed on the wafer 1. In the piezoelectric vibrating piece 100, the detection arm 120 extends from two opposite sides of the substantially square support portion 140 at the center, and the connecting arm 130 extends radially from the other two opposite sides. A pair of vibrating arms 110 extending in a substantially T shape with the connecting arm 130 as an axis is formed at the tip of the connecting arm 130. Such a piezoelectric vibrating piece 100 is called a double T-type vibrating piece and is used for a vibrating gyroscope or the like.

The piezoelectric vibrating piece 100 is surrounded by the frame portion 11 of the wafer 1 up to the vicinity of the periphery of the vibrating arm 110, the detection arm 120, and the connecting arm 130, and the frame portion 11 and the support portion on both sides of the detection arm 120 of the support portion 140. 140 are integrally connected to each other by the connecting portion 12. Due to such a structure, a plurality of piezoelectric vibrating reeds 100 can be formed simultaneously from the wafer 1.
In the present embodiment, the connecting portions 12 are provided on both sides of the detection arm 120, but may be provided on both sides of the connecting arm 130. Moreover, although the connection part 12 is provided in four places, it can also be provided in two places of the position which opposes on both sides of the support part 140, respectively.
The piezoelectric vibrating reed 100 of this embodiment is the same whether a plurality of piezoelectric vibrating reeds 100 are formed on the wafer 1 at the same time.

In FIG. 3, the connecting part 12 is formed with a notch-shaped constricted part 13 from both sides in the width direction of the connecting part 12 in the middle of the support part 140 and the frame part 11. A conical recess 14 is formed continuously in the width direction of the constricted portion 13 (see FIG. 4). In FIG. 3, the number of the concave portions 14 is three, but the number is not limited to three, and may be one or more, and can be easily separated as described later. It is only necessary to have a structural strength that does not cause the piezoelectric vibrating reed 100 to fall off during the manufacturing process, and can be set as appropriate.
The cross-sectional shape of the recess 14 is shown in FIGS.

  FIG. 4 shows a cross-sectional view of the recess 14 of this embodiment. In FIG. 4, the recess 14 is formed in a V-shaped cross section on the surface of the connecting portion 12, and the depth thereof is about ½ of the thickness of the wafer. As described above, the size and depth of the opening (the upper surface in the figure) of the cross-sectional shape of the recess 14 and the pitch between the adjacent recesses are easy to be separated, and the piezoelectric vibrating reed 100 falls off during other processes. Any structural strength can be set as long as the structural strength is sufficient.

5-7 has shown AA sectional drawing shown in FIG. 3 in case the recessed parts 14 and 15 are formed in the front and back both surfaces of the connection part 12, respectively. In FIG. 5, a concave portion 14 having a V-shaped cross section is formed on one surface (upper surface in the drawing) of the connecting portion 12, and a V-shaped cross section is formed on the other surface (lower surface in the drawing). A recess 15 is formed. The recesses 14 and 15 are formed at approximately the same position in the plane direction and have the same size, and the depth of each of the recesses 14 and 15 is approximately 1/3 of the wafer thickness.
The size, depth, and pitch of the recesses 14 and 15 can be easily separated as described above, and may be set appropriately as long as they have a structural strength that prevents the piezoelectric vibrating reed 100 from falling off during the manufacturing process. it can.

FIG. 6 is a cross-sectional view showing another embodiment of the recesses 14 and 15. In FIG. 6, a concave portion 14 is formed on one surface (upper surface in the drawing) of the connecting portion 12, and a concave portion 15 is formed on the other surface (lower surface in the drawing).
The concave portion 15 is disposed between the adjacent concave portions 14, and the size and depth thereof are set to be substantially the same as the concave portion 14.
When the number of the concave portions 14 is one, the concave portion 15 is arranged at a position (not shown) that does not intersect the concave portion 14 on a straight line connecting the constricted portions 13 (see FIG. 3) of the connecting portion 12 described above.

FIG. 7 is a cross-sectional view showing another embodiment of the arrangement of the recesses 14 and 15. In FIG. 7, a concave portion 14 is formed on one surface (upper surface in the drawing) of the connecting portion 12, and a concave portion 15 is formed on the other surface (lower surface in the drawing) at substantially the same planar position as the concave portion 14. ing.
At this time, the recess 14 is set larger than the recess 15. Which of the concave portions 14 and 15 is set larger can be selected by a method of breaking the piezoelectric vibrating piece 100 described later.
Further, the recesses 14 and 15 can be arranged alternately in the plane direction as shown in FIG.
Another embodiment of the arrangement of the recesses 14 and 15 is shown in FIG.

  8 shows the arrangement of the recesses 14 and 15, FIG. 8 (a) is a plan view of the main part, and FIG. 8 (b) shows a cross-sectional view of the connecting part 12 (of FIG. 8 (a)). CC cross section). 8 (a) and 8 (b), the recess 14 is arranged on a straight line connecting the constricted portion 13 of the connecting portion 12, and the recess 15 is within a range that does not intersect the recess 14 on the back surface side of the connecting portion 12. It is formed substantially parallel to the recess 14 at a position away from the support portion 140. The recesses 14 and 15 are approximately the same size.

FIG. 9 is a plan view of the main part of another embodiment of the connecting portion 12 of the piezoelectric vibrating piece 100. In FIG. 9, a notch-shaped constricted portion 13 is formed from both sides in the width direction in the middle of the connecting portion 12 between the support portion 140 and the frame portion 11 (see FIG. 3). Conical concave portions 14 are formed on a straight line connecting the width direction of the constricted portion 13 (three in the figure). Further, a groove 16 is formed on the surface opposite to the surface on which the recess 14 is formed, along the recess 14 provided continuously over the width of the connecting portion 12. The width of the groove portion 16 is set to be slightly larger than the diameter of the opening portion of the concave portion 14 and is in a range that does not cover the support portion 140.
The shape of the cross section will be described with reference to FIG.

10A shows the AA cross section of FIG. 9, and FIG. 10B shows the BB cross section of FIG. In FIG. 10A, the groove portion 16 is formed so as to penetrate the width direction of the connecting portion 12 at a depth that does not contact the bottom end of the concave portion 14.
In FIG. 10B, the groove portion 16 has a substantially conical cross-sectional shape, but this cross-sectional shape may be a trapezoidal shape or a V-shaped shape. The depth of the groove is about 1/3 of the thickness of the wafer 1. At this time, the sizes of the concave portion 14 and the groove portion 16 can be easily separated as described above, and may be combined and selected as appropriate as long as the structural strength is such that the piezoelectric vibrating reed 100 does not fall off during other steps. be able to.

FIG. 11 is a plan view of a main part of a piezoelectric vibrating piece 100 according to another embodiment of the present invention. In FIG. 11, four connecting portions 12 are formed between the support portion 140 of the piezoelectric vibrating piece 100 and the frame portion 11 of the wafer 1. A notch-like constricted portion 13 is formed on both sides of the connecting portion 12 on the support portion 140 side, and a constricted portion 18 is formed on the connecting portion 12 on the frame portion 11 side.
Conical recesses 14 and 17 are formed in a straight line connected to the narrow portions 13 and 18 in the width direction. As described above (see FIGS. 4 to 10), the recesses 14 and 17 may be formed only on one surface of the connecting portion 12, may be formed on both front and back surfaces, or may be formed on both front and back surfaces. In this case, it is possible to select a combination of the above-described arrangements of the concave portions, and it is possible to combine the concave portions and the groove portions.

12 and 13 are plan views showing other examples of the combination of the planar shape of the connecting portion 12 and the recess 14.
In FIG. 12, the connecting portion 12 is provided with a notched constricted portion 13 from both sides in the width direction of the connecting portion 12. One side of the constricted portion 13 has a shape along one side of the support portion 140 and is formed so that the width at this position is the narrowest. A concave portion 14 is formed at the narrowest position of the constricted portion 13.

In FIG. 13, the connecting portion 12 is formed with a constricted portion 13 having a narrow width near the support portion 140. A side surface of the constricted portion 13 extends in parallel with the connecting portion 12 and is connected to the support portion 140.
A recess 14 is formed along one side of the periphery of the support part 140 at the intersection of the connecting part 12 and the support part 140.

  As described above (see FIGS. 4 to 10), the recesses shown in FIGS. 12 and 13 may be formed only on one surface of the connecting portion 12, or may be formed on both front and back surfaces. When formed on both the front and back surfaces, the arrangement of the respective concave portions can be selected in combination, and the concave portion and the groove portion can be combined.

Next, the tuning-fork type piezoelectric vibrating piece 200 will be described with reference to FIG. The structure described for the double T-type piezoelectric vibrating piece 100 can also be applied to the structure of the tuning-fork type piezoelectric vibrating piece 200. The tuning-fork type piezoelectric vibrating piece 200 may be hereinafter referred to as a piezoelectric vibrating piece 200. In FIG. 14, in the tuning fork type piezoelectric vibrating piece 200, the end portion of the support portion 220 is connected to the frame portion 11 of the wafer 1 by the connecting portion 12. The support portion 220 is a base portion that supports a pair of vibrating arms 210 that perform bending vibration.
The connecting portion 12 extends from the frame portion 11 in a gentle arc shape toward the support portion 220, and is connected to the support portion 220 at the narrowest portion to support the tuning fork type piezoelectric vibrating piece 200. Yes.

  A concave portion 14 having a V-shaped cross section is continuously formed along the end shape of the support portion 220 at a position where the connecting portion 12 intersects the support portion 220 (three in FIG. 14). As described above (see FIGS. 4 to 10), the recess 14 may be formed only on one surface of the connecting portion 12, may be formed on both front and back surfaces, or may be formed on both front and back surfaces. The arrangement of the recesses can be selected in combination, and the recesses and the grooves can be combined.

Next, a method for manufacturing the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200 will be described with reference to FIGS. At this time, the manufacturing method of the recesses is basically the same regardless of the shape and size, and therefore the recesses 14 and 15 will be described. FIG. 15 schematically shows a BB cross section (see FIG. 3) of the connecting portion 12 of the piezoelectric vibrating piece 100 of the present embodiment.
When the piezoelectric vibrating piece 100 of the present embodiment is a quartz vibrating piece, as shown in FIG. 1, a quartz substrate (cut out so that the X axis is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis). The piezoelectric vibrating piece 100 is formed by processing the wafer 1) by photolithography or the like.

In FIG. 15, a corrosion resistant film 5 is formed on the front and back surfaces of the wafer 1 cut out as described above by vapor deposition or the like, and a resist film 6 is applied on the upper surface of the corrosion resistant film 5 (FIG. 15 (1)).
Subsequently, external pattern exposure and external pattern development are performed using a mask (not shown) that matches the external shape of the piezoelectric vibrating piece 100 and the shapes of the recesses 14 and 15 (FIG. 15B). The resist film 6 is removed from the outer shape 141 (see FIG. 3) of the piezoelectric vibrating piece 100 and the portion indicated by the opening 7 having a position and size matching the shape of the opening of the recesses 14 and 15.

  Next, the developed exposed portion of the corrosion-resistant film 5 is peeled off by an etching solution (FIG. 15 (3)), and the corrosion-resistant film 5 has an outer shape 141 and an opening 8 having the same shape as the resist film formed in the above-described process. It is formed. Subsequently, the resist film 6 is peeled off (FIG. 15 (4)). At this time, the outer shape 141 of the piezoelectric vibrating piece 100 and the corrosion-resistant film 5 in the opening 8 having the shape of the recesses 14 and 15 are removed.

Subsequently, the outer shape of the piezoelectric vibrating piece 100 is etched (FIG. 15 (5)). At this time, the recesses 14 and 15 are also formed at the same time. The size of the opening 8 of the corrosion-resistant film 5 is set so that the recesses 14 and 15 do not penetrate even if etching is performed under the same conditions. In this embodiment, the depth is about 1/3 of the thickness of the wafer 1. Is set as follows.
The sizes of the recesses 14 and 15 are adjusted by the size of the opening 8 and the etching time.
Thereafter, electrodes of the piezoelectric vibrating piece 100 are formed, but the description thereof is omitted.

Next, a manufacturing method in the case where the groove 111 is formed in the vibrating arm 110 of the piezoelectric vibrating piece 100 will be described. Reference is also made to FIG.
FIG. 16 is a perspective view showing the vibrating arm 110 of the piezoelectric vibrating piece 100. In FIG. 16, the resonating arm 110 is connected by a connecting arm 130 extending from the support portion 140. The resonating arm 110 extends from the connecting arm 130 on both sides in the perpendicular direction, and a connecting portion 131 of the resonating arm 110 and the connecting arm 130 is formed at the base portion thereof. A groove 111 is formed in the vibrating arm 110. Although not shown, the groove 111 is also formed on the back side.

  It is known that the groove 111 is formed in the vibrating arm 110, whereby the piezoelectric vibrating piece 100 can be downsized and the CI value can be kept low. A method of manufacturing the piezoelectric vibrating piece 100 having the groove 111 and the recesses 14 and 15 will be described with reference to FIG.

  FIG. 17 is a cross-sectional view showing a method of manufacturing the piezoelectric vibrating piece 100 having the groove 111 of the vibrating arm 110 and the recesses 14 and 15 of the connecting portion 12 (see also FIGS. 3 and 16). In FIG. 17, the piezoelectric vibrating piece 100 has a cross-section H of a quartz substrate cut out so that the X axis is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis, as shown in FIG. A piezoelectric vibrating piece 100 of the type is formed.

The anticorrosion film 5 is formed on the front and back surfaces of the crystal substrate (wafer 1) cut out as described above by vapor deposition or the like, and a resist film 6 is applied on the upper surface of the anticorrosion film 5 (FIG. 17A).
Subsequently, external pattern exposure and external pattern development are performed using a mask (not shown) matched to the external shape of the piezoelectric vibrating piece 100 (FIG. 17B).
Next, the developed exposed portion of the corrosion-resistant film 5 is peeled off by the etching solution (FIG. 17 (3)), and the resist film 6 is peeled off (FIG. 17 (4)). At this time, only the corrosion-resistant film 5 having a shape close to the outer shape of the piezoelectric vibrating piece 100 is left.

  Next, the entire surface of the wafer 1 including the remaining surface of the corrosion-resistant film 5 is coated with a resist film 6 (FIG. 17 (5)), and pattern exposure and development of the groove 111 and the recesses 14 and 15 are performed (FIG. 17). (6)), however, the resist film 6 has the openings 9 corresponding to the grooves 111 and the openings 7 corresponding to the recesses 14 and 15 removed. Thereafter, external etching is performed, and then the corrosion-resistant film 5 is removed in accordance with the shape of the resist film 6 (FIG. 17 (7)).

Subsequently, the groove 111 and the recesses 14 and 15 are etched. This etching process is half-etching, and the etching time is controlled and dug down to a predetermined depth to form a groove and a recess with a predetermined shape and depth (FIG. 17 (8)).
Thereafter, the resist film 6 and the corrosion-resistant film 5 are peeled off to form the piezoelectric vibrating piece 100 (FIG. 17 (9)). This piezoelectric vibrating piece 100 (including the piezoelectric vibrating piece 200) is connected to the frame portion 11 of the wafer 1. In this state, electrodes are formed on the piezoelectric vibrating piece 100, but the description is omitted.

Next, a method for separating the piezoelectric vibrating piece 100 from the frame portion 11 will be described with reference to FIGS. FIG. 18 is a partial plan view showing a state where the connecting portion 12 is separated. Although four connecting portions are provided in this embodiment, one connecting portion is shown and described as a representative. In FIG. 18, the support portion 140 and the connecting portion 12 are connected to each other. Although not shown, when the frame portion 11 is supported by a jig or the like, the substantial center of the support portion 140 is folded and pushed down by the jig, the constricted portion Stress concentration occurs at the location of the recess 13 and the recess 14 and the separation is performed.
FIG. 19 shows a CC cross section of FIG. 18 when a state where the piezoelectric vibrating piece 100 is folded is shown. In FIG. 19, the support portion 140 and the connecting portion 12 are separated in the direction of the arrow in the drawing, and the piezoelectric vibrating piece 100 is completed. The tuning fork type piezoelectric vibrating piece 200 is also formed by being folded in the same manner.

FIG. 20 shows a cross-section when the concave portion 14 and the concave portion 15 described above are separated when the planar positions are shifted. When the support portion 140 is folded and pushed down with a jig (in the direction of arrow D in FIG. 8B), the piezoelectric vibrating piece 100 is separated at a position where the concave portion 14 on the upper surface side and the concave portion 15 on the lower surface side are connected. Is separated from the frame portion 11, and the piezoelectric vibrating piece 100 is formed.
The piezoelectric vibrating piece 100 (piezoelectric vibrating piece 200) formed in this way is stored in a package.

Next, the vibrating gyroscope 400 and the piezoelectric vibrator 500 having the above-described configuration and including the manufactured piezoelectric vibrating piece 100 and the tuning fork type piezoelectric vibrating piece 200 will be described.
21 and 22 are cross-sectional views showing a state where the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200 are stored in a package. FIG. 21 is a schematic cross-sectional view showing the configuration of the vibration type gyroscope 400. As shown in FIG. 21, the ceramic package 410 is a box-shaped package having a space inside. The ceramic package 410 is made of ceramic such as alumina, for example.

  A sealing portion 420 is provided at an upper edge portion of the ceramic package 410, and the sealing portion 420 is formed in a shape along the edge portion of the ceramic package 410 with a metal material such as Kovar. Further, a metal lid 430 is placed and fixed on the upper portion of the sealing portion 420, and a hollow box is formed by the ceramic package 410, the sealing portion 420, and the lid 430.

The bottom part 411 of the ceramic package 410 thus formed is provided with an IC chip 450 as a control circuit and other circuit elements (not shown), and the step part 412 is a tab formed on the surface with a body foil or the like. A circuit board 460 on which 461 is formed is fixed. A part of the tab 461 is bent upward in the figure, and the tip part thereof is connected by a stud bump 312 formed on the electrode 150 on the surface of the support part 140 of the piezoelectric vibrating piece 100 and is piezoelectric. The resonator element 100 is supported substantially horizontally with respect to the bottom surface of the ceramic package 410.
Although not shown, the ceramic package 410 is formed with electrodes that connect the circuit board 460, the piezoelectric vibrating piece 100, the IC chip 450, other circuit elements, and circuit elements and power supplies arranged outside the ceramic package 410. ing. The piezoelectric vibrating piece 100 is vibrated accurately when a constant driving voltage is applied from the tab 461.

FIG. 22 is a schematic cross-sectional view showing a configuration of a cylinder-type piezoelectric vibrator 500. As shown in FIG.
In FIG. 22, a piezoelectric vibrator 500 has a metal cap 530 for housing a tuning fork type piezoelectric vibrating piece 200 therein. The cap 530 is press-fitted into the stem 520, and the inside is kept in a vacuum state.
Two leads 510 are provided through the stem 520. An electrode (not shown) formed on the support portion 220 of the tuning fork type piezoelectric vibrating piece 200 is fixed and held on the lead 510 with a conductive adhesive or the like.
When a constant drive voltage is applied from the lead 510 to the tuning-fork type piezoelectric vibrating piece 200 configured as described above, the vibrating arm 110 vibrates accurately and functions as the piezoelectric vibrator 500.

Next, a method for forming the stud bump 312 on the piezoelectric vibrating piece 100 will be described.
FIG. 23 is a cross-sectional view showing a main process for forming the stud bump 312, and FIG. 24 is a partial plan view of the main part. In FIG. 23A, a gold wire 310 is inserted through the center of a capillary 300 attached to the tip of a horn (not shown) provided in the ultrasonic processing machine, and the desired bump size and A gold wire 310 having the same volume is projected from the tip of the capillary 300.
Next, the tip of the gold wire 310 is melted by heat generated by discharge from a torch (not shown) to form a spherical bump 312 (shown in FIG. 23B).

  In such a state, the bump 312 is pressed against the upper surface of the electrode 150 such as the drive electrode or the detection electrode formed on the support portion 140 of the piezoelectric vibrating piece 100, and the horn (including the capillary 300) vibrates in the direction of the arrow. The bump 312 is welded to the electrode 150 (shown in FIG. 23C). Then, the bump 312 and the gold wire 310 are separated by pulling up the capillary 300 after a predetermined time has elapsed. Thus, the bump 312 formed on the electrode 150 is a stud bump. At this time, the relationship between the vibration direction of the capillary 300 (horn) and the aforementioned recesses 14 and 15 is shown in FIG.

  FIG. 24 is a partial plan view showing a state of stud bump formation. In FIG. 24, the capillary 300 is vibrated in the direction of the arrow in the figure. This vibration direction is the same as the direction in which the concave portion 14 of the connecting portion 12 is continuously formed. At this time, the bump 312 is formed as an elliptical stud bump that is long in the vibration direction of the capillary 300. The tab 461 and the piezoelectric vibrating piece 100 described above are connected by the stud bump formed in this way, and the vibrating gyroscope 400 as shown in FIG. 21 is configured.

The piezoelectric vibrator 500 configured as described above and manufactured by the above-described manufacturing method can be used as a time standard for a timepiece or an electronic device.
The piezoelectric vibrating piece 100 is used in the vibrating gyroscope 400 as an angular velocity sensor by rotating the Z-axis as a rotation axis, generating Coriolis force, and detecting this force. It can be mounted on electronic devices such as navigation devices and camera shake prevention devices such as cameras.

  Therefore, according to the embodiment described above, the piezoelectric vibrating piece 100 and the tuning fork type piezoelectric vibrating piece 200 are simultaneously formed on the wafer 1 by photolithography, and the piezoelectric vibrating piece 100 and the tuning fork type piezoelectric vibrating piece 200 are respectively provided. The support parts 140 and 220 and the frame part 11 of the wafer 1 are connected by a connecting part 12. Since the concave portion 14 is formed on one surface of the connecting portion 12 or the concave portion 14 is formed on one surface and the concave portion 15 is formed on the other surface, the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200 are attached. When separating from the wafer 1, the support portions 140 and 220 are folded and pushed by a jig or the like, so that stress concentration occurs in the recesses 14 and 15, and can be easily separated. The production efficiency of the type piezoelectric vibrating piece 200 can be increased. Moreover, since the connection part 12 is comprised in the frame part 11, it contributes also to size reduction.

  Further, since the recesses 14 and 15 have a substantially V-shaped cross-section, the recesses 14 and 15 are folded from the vicinity of the bottom end, so that the positions and shapes of the break-away portions are small and an accurate outer shape can be obtained. As a result, there is an effect that a stable resonance frequency can be obtained.

  The connecting portion 12 is formed to protrude from the support portion 140 or the support portion 220 that connects the vibrating arms of the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200. Since the support portions 140 and 220 are places where there is little influence on the vibration of the vibrating arm or the detection arm, the resonance frequency is hardly affected by the variation in the shape of the separation portion when the piezoelectric vibrating piece is folded. effective.

Furthermore, since a constricted portion having a narrower width than the other portions is formed in a part of the connecting portion 12 and the concave portion is formed in the constricted portion, the stress is further increased when the piezoelectric vibrating piece is separated. Concentration is likely to occur and it can be folded even with a small force. As a result, the production efficiency is improved, and the variation in the position and shape of the separation portion of the piezoelectric vibrating piece is reduced.
In addition, since it is separated by a straight line connecting the narrowest portions of the constricted portion, it can be accurately separated in a predetermined shape, so that the CI value can be kept low, the yield is improved, and the cost is reduced. be able to.

  As described above, the size, shape, and arrangement of the recesses 14 and 15 can be suitably selected and combined depending on the shape, thickness, and material of the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200, thereby increasing production efficiency. be able to. Further, according to the embodiment (see FIG. 8) in which the concave portion 14 and the concave portion 15 are displaced in parallel, they are separated in the middle of the process of manufacturing the piezoelectric vibrating piece 100 and the tuning fork type piezoelectric vibrating piece 200. It can be prevented from falling off and can be easily separated at the time of folding. In particular, when the stud bumps are formed, the horn (including the capillary 300) is vibrated, or when the gold wire 310 is separated after the stud bumps 312 are formed (see FIG. 23D), the piezoelectric vibrating piece 100 is separated and dropped off. There is also an effect that this can be prevented.

  Further, in the structure by the combination of the concave portion 14 and the groove portion 16 as described above (see FIGS. 9 and 10), when the piezoelectric vibrating piece is folded, it is linearly separated along the concave portion and the groove and separated. There are few unevenness | corrugations of a cross section, and it can reduce the influence on the vibration of a piezoelectric vibrating piece by a separation part shape. Furthermore, by combining the concave portion 14, the groove portion 16, and the constricted portion 13, separation can be achieved even when the detachment force at the time of detachment is small, so that the production efficiency can be further improved.

  In addition, the piezoelectric vibrating piece 100 and the tuning-fork type piezoelectric vibrating piece 200 of the present invention are formed by photolithography. After a corrosion-resistant film is formed on the surface of the wafer 1, a resist film is formed, and the process includes exposure, development, and etching. At this time, the recesses 14 and 15 can form a recess that does not penetrate at the same time as the outer shape formation by using an exposure mask having an opening set smaller than the outer shape portion of the piezoelectric vibrating piece described above in the exposure process. . Thus, since the outer shape formation and the concave portion formation can be performed in the same process, the production efficiency can be increased.

  Furthermore, the piezoelectric vibrator 500 and the vibratory gyroscope 400 according to the present invention are stored in a package in which the tuning fork type piezoelectric vibratory piece 200 or the piezoelectric vibratory piece 100 manufactured by the above-described structure and method is vacuum. Therefore, it is not affected by the environment outside the package such as dust and humidity, and the vibration piece is vibrated in a vacuum environment, so that more stable vibration can be maintained for a long period of time. In addition, since it is stored in the package, there is an effect that it is easy to handle.

  Further, in the vibrating gyroscope 400 according to the present invention, the connection between the piezoelectric vibrating piece 100 and the circuit board 460 is performed by the stud bump 312 formed on the piezoelectric vibrating piece 100. An ultrasonic welding method is adopted to form the stud bump 312. By making the vibration direction of the ultrasonic wave coincide with the continuous direction of the recesses 14 and 15, the frame is generated by vibration when the stud bump 312 is formed. The piezoelectric resonator element and the piezoelectric vibrating piece can be prevented from being separated from each other, and when being separated, it can be easily separated from the concave portion, and the working efficiency can be improved. .

In addition, this invention is not limited to the above-mentioned Example, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, in the above-described embodiment, the concave portions 14 and 15 have a conical shape having a substantially V-shaped cross section, but may be a quadrangular shape. In the case of a quadrangular shape, the opposing angle is a straight line connecting the constricted portions 13 in the width direction. If it is made to correspond to, it will become still easier to fold.
Further, for example, a shape in which a plurality of the concave portions 14 are continuous, that is, the opening planar shape may be an elongated elliptical shape.

Moreover, in this embodiment, although the connection part 12 was formed in the linear part of the periphery of the support part 140, in this invention, you may provide a connection part in four corner | angular parts of the support part 140, other You may provide in a place.
Electrode separation can also be performed by forming an electrode on the connecting portion 12 and then folding it.

  In the present invention, the shape of the constricted portion 13 and the combination of the concave portions 14 and 15 and the groove portion 16 are not limited to the present embodiment, and the combination is free depending on the material, thickness, and planar size of the piezoelectric vibrating piece. is there.

  Therefore, according to the above-described embodiment, a piezoelectric vibrating piece that is small in size, has good mass productivity, and can obtain a stable resonance frequency, a method for manufacturing the piezoelectric vibrating piece, a piezoelectric vibrator including the piezoelectric vibrating piece, and a vibrating gyroscope And a method of manufacturing a piezoelectric vibrator and a vibratory gyroscope including the piezoelectric vibrating piece.

  DESCRIPTION OF SYMBOLS 1 ... Wafer, 11 ... Frame part, 14, 15 ... Recessed part, 100, 200 ... Piezoelectric vibration piece, 110, 210 ... Vibration arm, 120 ... Detection arm, 130 ... Connection arm, 140, 220 ... Support part, 400 ... Vibration Mold pressure gyroscope, 500 ... piezoelectric vibrator.

Claims (3)

A method for manufacturing a vibrating gyroscope including a piezoelectric vibrating piece formed by photolithography from a wafer made of a piezoelectric material,
A part of the piezoelectric vibrating piece is connected to a frame portion of the wafer formed around the piezoelectric vibrating piece by a plate-like connecting portion, and a plurality of recesses are formed on at least one surface of the connecting portion. It is continuously drilled in the width direction of the connecting portion,
A stud bump is formed by ultrasonic welding on at least one of the drive electrode and the detection electrode formed on the piezoelectric vibrating piece,
A method for manufacturing a vibrating gyroscope, characterized in that the ultrasonic vibration direction and a direction in which the concave portions are made to coincide with each other. A method for manufacturing the vibratory gyroscope according to claim 1,
The connecting portion is formed with a narrow portion narrower than other portions,
The recess is formed in the constricted portion;
The sectional shape rectangular recesses, method of manufacturing the vibrating gyroscope, characterized in that the opposing angle and a shape-matched on a straight line connecting the constricted portion in the width direction. A method for manufacturing a vibrating gyroscope according to claim 1 or 2,
A method for manufacturing a vibrating gyroscope, wherein the plurality of recesses are continuous and the planar shape of the opening is an elongated elliptical shape.

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