JP7454962B2 - Piezoelectric wafer, piezoelectric wafer manufacturing method, and piezoelectric vibrating piece manufacturing method - Google Patents

Description

The present invention relates to a piezoelectric wafer, a method for manufacturing a piezoelectric wafer, and a method for manufacturing a piezoelectric vibrating piece, and specifically relates to a piezoelectric wafer on which a plurality of piezoelectric vibrating pieces are formed.

For example, in electronic devices such as mobile phones and personal digital assistants, piezoelectric devices with internal piezoelectric vibrating pieces made of crystal, etc. are used as time sources, timing sources for control signals, reference signal sources, etc. Oscillators are widely used.
The piezoelectric vibrating piece is used by breaking off each small piezoelectric vibrating piece from a piezoelectric wafer in which a plurality of piezoelectric vibrating pieces are formed on a large-area piezoelectric wafer. A piezoelectric wafer is a large-area wafer that is thinned by lapping, polishing, etc. to the thickness of a piezoelectric vibrating piece, and then a piezoelectric wafer is connected to a frame part on the wafer at a connecting part by transfer using photolithography technology, etching, etc. A plurality of chip patterns of vibrating pieces are formed.

However, as piezoelectric vibrators have become smaller in recent years, piezoelectric vibrating pieces have also become smaller and thinner, making it difficult to directly contact probe the piezoelectric vibrating pieces for frequency measurement on a wafer. An electrode pattern is routed from a pair of excitation electrodes formed on the vibrating piece, and electrode pads are arranged on the frame portion of the wafer.
The frequency of each piezoelectric vibrating piece is measured by pressing a probe or the like against the corresponding electrode pad. Thereafter, the piezoelectric vibrating piece is cut into pieces at the connecting portion.

By the way, when routing the electrodes from the pair of excitation electrodes formed on each piezoelectric vibrating piece to the pair of electrode pads formed on the frame portion, it is also necessary to separate the electrode pads and the routing electrodes.
It is possible to divide a pair of electrode pads for one piezoelectric vibrating piece on the main surface of the frame part, but for the electrode pads between adjacent piezoelectric vibrating pieces, it is possible to divide the electrode pads on the side surface in addition to the main surface. need to be divided.
Therefore, in addition to the exposure to divide the electrode pads on the main surface, it is necessary to expose the side surfaces of the frame obliquely to divide the pad electrodes on the side surfaces, and this oblique exposure increases the number of steps. I had left it behind.

Patent No. 4784700

An object of the present invention is to manufacture piezoelectric wafers and piezoelectric vibrating pieces with fewer steps.

(1) In the invention according to claim 1, a frame part, a plurality of piezoelectric vibrating pieces each having a vibrating arm part connected to the frame part in parallel, and each of the piezoelectric vibrating pieces, A first excitation electrode and a second excitation electrode for vibrating the vibrating arm, and electrically connected to the first excitation electrode formed on the frame corresponding to each of the piezoelectric vibrating pieces. A residue forming portion formed between a first electrode pad, a second electrode pad electrically connected to the second excitation electrode, and an adjacent connection portion connecting the piezoelectric vibrating piece to the frame portion. and an inclined surface formed as a residue by the residue forming section, the first electrode pad formed corresponding to one piezoelectric vibrating piece among two adjacent piezoelectric vibrating pieces, and the other piezoelectric vibrating piece. The piezoelectric wafer is characterized in that the second electrode pad formed corresponding to the piece is divided by the main surface of the frame portion and the inclined surface formed as the residue.
(2) In the invention according to claim 2, the residue forming portion is formed in a convex shape in the direction in which the piezoelectric vibrating piece is formed with respect to the frame portion, and the inclined surface is formed between the frame portion and the 2. A piezoelectric wafer according to claim 1, wherein the piezoelectric wafer is formed between both sides of a convex-shaped residue forming portion.
(3) In the invention according to claim 3, the residue forming part is formed in a concave shape recessed in a direction opposite to the direction in which the piezoelectric vibrating piece is formed with respect to the frame part, and the inclined surface is is formed on both side surfaces and the bottom surface of the concave shape.
(4) In the invention according to claim 4, there is provided a method for manufacturing a piezoelectric wafer according to claim 1, claim 2, or claim 3, comprising: a wafer preparation step of preparing a wafer; , an outer shape forming step of forming the outer shape of the piezoelectric wafer, and after forming a metal material on the surface of the wafer formed in the outer shape forming step , the first excitation electrode and the first excitation electrode are formed by photolithography on the metal material. an electrode forming step of forming two systems of electrodes, a first system of one electrode pad and a second system of the second excitation electrode and the second electrode pad; and from the first electrode pad and the second electrode pad. a frequency adjustment step of adjusting the frequency of each of the piezoelectric vibrating pieces by applying a driving voltage, and in the electrode forming step, electrodes corresponding to the two systems of electrodes are formed in photolithography for the metal material. There is provided a method of manufacturing a piezoelectric wafer, characterized in that the electrodes of the first system and the second system are divided by applying a patterned electrode mask and performing exposure from the main surface side.
(5) In the invention according to claim 5, a plurality of piezoelectric wafers manufactured by the piezoelectric wafer manufacturing method according to claim 4 and the piezoelectric wafer manufacturing method are connected to the frame portion in a plurality of piezoelectric wafers. Provided is a method for manufacturing a piezoelectric vibrating piece, comprising a step of cutting each electric vibrating piece into pieces.

According to the present invention, the first electrode pad formed corresponding to one piezoelectric vibrating piece among two adjacent piezoelectric vibrating pieces and the second electrode pad formed corresponding to the other piezoelectric vibrating piece are Since it is divided by the main surface of the frame portion and the inclined surface formed as a residue, piezoelectric wafers and piezoelectric vibrating pieces can be manufactured with fewer steps.

FIG. 2 is an explanatory diagram showing the configuration of a piezoelectric wafer in the first embodiment. FIG. 3 is an enlarged view showing the vicinity of a piezoelectric vibrating piece in the first embodiment. FIG. 3 is an enlarged view showing a residue forming part and a slope formed by the residue in the first embodiment. 3 is a flowchart showing a piezoelectric wafer manufacturing process in the first embodiment. FIG. 7 is an enlarged view showing the vicinity of a piezoelectric vibrating piece of a piezoelectric wafer in a second embodiment. It is an explanatory view showing a modification of a piezoelectric wafer.

Hereinafter, preferred embodiments of a piezoelectric wafer, a piezoelectric wafer manufacturing method, and a piezoelectric vibrating reed manufacturing method of the present invention will be described in detail with reference to FIGS. 1 to 6.
(1) Overview of Embodiment A piezoelectric wafer 1 according to the present embodiment includes a plurality of frame sections 2, and a plurality of piezoelectric vibrating pieces 3 are connected to each frame section 2 by a connection section 21. The piezoelectric vibrating piece 3 and the frame part 2 each have a first excitation electrode 91 and a first electrode pad 23 of the piezoelectric vibrating piece 3, and a second excitation electrode 92 and a second electrode pad, as electrodes that are divided into two systems. 24 is formed.
In this embodiment, the convex-shaped residue forming part 4 is provided on the frame part 2, and the inclined surfaces 41 and 42, which are etching residues, are formed between the side surface of the residue forming part 4 and the side surface of the frame part 2. The division between the electrode pads (first electrode pad 23, second electrode pad 24) of adjacent piezoelectric vibrating pieces 3 in the frame part 2 can be performed only by main surface exposure, and the oblique exposure process can be reduced. can.
In addition to the convex-shaped residue forming part 4, the concave-shaped residue forming part 5 may be used. In this case, inclined surfaces 51 to 53 are formed inside the concave shape, and the electrode pads are divided by exposing the main surface to these inclined surfaces 51 to 53.

(2) Details of Embodiment FIG. 1 shows a part of the configuration of a piezoelectric wafer 1 in a first embodiment.
FIG. 2 is an enlarged view showing the vicinity of the piezoelectric vibrating piece 3.
In addition, in each figure of this embodiment, a hidden line is represented by a dotted line, and a broken part is represented by a dashed-dotted line.
As shown in FIG. 1, the piezoelectric wafer 1 of the first embodiment includes a plurality of frame parts 2 extending in the X direction and two frame parts 2 extending in the Y direction formed at both ends in the X direction. A plurality of frame parts 2 extending in the X direction are arranged in parallel in the Y direction at equal intervals, and both ends thereof are connected to the frame part 2 extending in the Y direction.
Although the shape of the piezoelectric wafer 1 is shown as a rectangle in FIG. 1, the outer edge side of the piezoelectric wafer 1 has a shape that follows the shape of the wafer before processing.
Note that the piezoelectric wafer 1 is formed from a piezoelectric material such as quartz, lithium tantalate, lithium niobate, etc., and quartz is used in this embodiment.
Hereinafter, when simply referring to the frame section 2, it will be explained as referring to a frame extending in the X direction.

As shown in FIG. 2, a plurality of piezoelectric vibrating pieces 3 whose longitudinal direction is in the Y direction are connected to each frame part 2 by a connecting part 21 that functions as a connecting part.
In each frame portion 2, a first electrode pad 23 and a second electrode pad 24 for each piezoelectric vibrating piece 3 are formed side by side. That is, in each frame portion 2, first electrode pads 23 and second electrode pads 24 are alternately formed in line in the X direction.
In each frame part 2, a residue forming part 4 for dividing the electrode is formed on the side surface of the frame part 2 between two adjacent piezoelectric vibrating pieces 3. This residue forming portion 4 is formed between the second electrode pad 24 of one piezoelectric vibrating piece 3 and the first electrode pad 23 of the other piezoelectric vibrating piece 3.

The piezoelectric vibrating piece 3 includes a pair of vibrating arms 7a, 7b, a base 8, and a pair of supporting arms 9a, 9b.
A connecting portion 21 is connected to the side of the base 8 facing the frame portion 2, and a pair of vibrating arms 7a and 7b are lined up on the side opposite to the connecting portion 21 in the longitudinal direction (Y direction). It has been extended to
The base portion 8 is provided with support arms 9a and 9b for mounting the piezoelectric vibrating pieces 3 separated into pieces into a piezoelectric vibrator package. The pair of support arms 9a and 9b extend in the width direction (X direction) of the piezoelectric vibrating piece 3 from the side surface of the base 8 on the connection part 21 side, and then bend in a direction away from the frame part 2, and the vibrating arms They are extended so as to line up on both outsides of 7a and 7b.

The pair of vibrating arms 7a and 7b are arranged parallel to each other, and vibrate with the end on the base 8 side as a fixed end and the tip as a free end.
The pair of vibrating arms 7a, 7b includes widened portions 71a, 71b formed on both sides to be wider than the reference width, which is the width at approximately the center of the entire length. The widened portions 71a, 71b have a function of increasing the weight of the vibrating arm portions 7a, 7b and the moment of inertia during vibration. This makes it easier for the vibrating arms 7a, 7b to vibrate, making it possible to shorten the length of the vibrating arms 7a, 7b, thereby achieving miniaturization.
Note that although the piezoelectric vibrating piece 3 according to each embodiment and modification has widened portions 71a and 71b formed in the vibrating arms 7a and 7b, a piezoelectric vibrating piece without widened portions may be used.

In the piezoelectric wafer 1 of this embodiment, although not shown, the vibration state is adjusted to vibrate within a predetermined frequency range (frequency A weight metal film (consisting of a coarse adjustment film and a fine adjustment film) for performing adjustment) is formed. By removing an appropriate amount of this weight metal film by, for example, irradiating it with laser light, the frequency can be adjusted and the frequency of the pair of vibrating arms 7a and 7b can be kept within the range of the nominal frequency of the device. It has become. It is also possible not to form this weight metal film, similarly to the widened portion.

FIG. 2(b) is a cross-sectional view taken along the line V1-V1 shown in FIG. 2(a) as viewed in the direction of the arrow.
As shown in FIGS. 2A and 2B, grooves 72a and 72b having a constant width extending in the longitudinal direction are formed in the pair of vibrating arms 7a and 7b. The grooves 72a, 72b are formed to be recessed in the Z direction on both main surfaces (front and back surfaces) of the pair of vibrating arms 7a, 7b. The groove portions 72a, 72b are formed from the base end of the vibrating arm portions 7a, 7b (the surface of the base portion 8 opposite to the connecting portion 21) to the front side of the widened portions 71a, 71b.
Since the grooves 72a and 72b are formed on both main surfaces, each of the pair of vibrating arms 7a and 7b has an H-shaped cross section.
Note that although grooves 72a and 72b are formed in the piezoelectric vibrating piece 3 of the piezoelectric wafer 1 according to each embodiment and modification, a piezoelectric vibrating piece without grooves may be used.

As shown in FIGS. 2(a) and 2(b), two systems of excitation electrodes (a first excitation An electrode 91 and a second excitation electrode 92) are formed. The first excitation electrode 91 and the second excitation electrode 92 are electrodes that vibrate the pair of vibrating arms 7a, 7b at a predetermined resonant frequency in a direction toward or away from each other when a voltage is applied. They are patterned and formed on the vibrating arms 7a, 7b in a separated state.
Specifically, the first excitation electrode 91 is formed mainly on both side surfaces of one vibrating arm 7a and in both grooves 72b of the other vibrating arm 7b in a state in which they are electrically connected to each other. ing.
Further, second excitation electrodes 92 are formed mainly in both grooves 72a of one vibrating arm 7a and on both side surfaces of the other vibrating arm 7b in a state in which they are electrically connected to each other.

Although not shown, a mount electrode is formed on one main surface side of the support arms 9a, 9b of the piezoelectric vibrating piece 3 as a mount part when the piezoelectric vibrating piece 3 is mounted on a package.
The mount electrode of the support arm 9 a is connected to the first excitation electrode 91 of the base 8 and further connected to the first electrode pad 23 .
The mount electrode of the support arm 9b is connected to the second excitation electrode 92 of the base 8, and further connected to the second electrode pad 24.
A voltage is applied to the two systems of the first excitation electrode 91 and the second excitation electrode 92 via the first electrode pad 23 and the second electrode pad 24 in the manufacturing stage before the piezoelectric vibrating piece 3 is separated into pieces. On the other hand, after being diced into pieces, a voltage is applied via a pair of mount electrodes.

The various electrodes (first excitation electrode 91, second excitation electrode 92, mount electrode, routing electrode, first electrode pad 23, second electrode pad 24) in this embodiment are made of, for example, chromium (Cr). It is a laminated film of gold (Au) and a chromium film that has good adhesion to crystal, and then a thin gold film is applied to the surface after the film is formed using a chromium film that has good adhesion to crystal. However, this is not limited to this case, and for example, a thin gold film may be further laminated on the surface of a laminated film of chromium and nichrome (NiCr), and chromium, nickel, aluminum (Al), titanium (Ti) etc. It may be formed of a single layer film.

Details of the formation of these various electrodes will be described later, but they are performed in the same manner as in the conventional method. That is, an electrode material is formed into a film by vapor deposition or sputtering over the entire piezoelectric vibrating piece 3, including the inside of the grooves 72a and 72b, before forming each electrode.
Then, by leaving various electrode parts and removing parts other than the electrodes by a photolithography process, two systems of electrode lines are formed.

FIG. 3 is an enlarged view showing details of the residue forming part 4, in which (a) shows a plane view, (b) shows a side view, and (c) shows a perspective view.
As explained in FIG. 2, this residue forming part 4 is formed in a convex shape between two adjacent piezoelectric vibrating pieces 3 in the frame part 2.
As shown in FIG. 3, sloped surfaces 41 and 42 made of etching residue are formed on both sides of the residue forming portion 4. The sloped surfaces 41 and 42 are composed of two sloped surfaces 41 and 41 and sloped surfaces 42 and 42 directed from both main surfaces toward the center in the thickness direction.

Incidentally, the outer shape of the piezoelectric vibrating piece 3 is formed by a wet etching method, as will be described later. During this wet etching, an etching residue is formed that is inclined between an XZ plane perpendicular to the main surface (XY plane) and a YZ plane perpendicular to the main surface.
In the case of this embodiment, by forming the residue forming part 4 that protrudes from the frame part 2 in the Y direction, both outer side surfaces (YZ plane) of the residue forming part 4 and side surfaces (XZ plane) of the frame part 2 are formed. An etching residue due to the inclined surfaces 41, 41 and an etching residue due to the inclined surfaces 42, 42 are formed.

Regarding the electrode material deposited on the entire frame portion 2, the electrode material is deposited between the first electrode pad 23 and the second electrode pad 24 for one piezoelectric vibrating piece 3, and the second electrode material between the adjacent piezoelectric vibrating pieces 3. The space between the electrode pad 24 and the first electrode pad 23 is divided.
This division between the electrodes is achieved by forming the external shape of the piezoelectric wafer 1 shown in FIG. removed. During this exposure, the sloped surfaces 41 and 42 of the residue forming part 4 are projected by the exposure when viewed from the main surface side, so that the electrode material of the sloped surfaces 41 and 42 becomes the object of removal. Therefore, the frame side surface 26 of the frame portion 2 is divided by exposing the inclined surfaces 41 and 42 formed on both sides of the residue forming portion 4 from both main surfaces.
That is, as shown in FIG. 3, the first electrode pad 23 and the second electrode pad 24 formed on the frame part 2 are divided by the main surface, and there is no residue formed on the side surface 26 of the frame. The portion 4 is divided by inclined surfaces 41 and 42.

As shown in FIG. 3, the parts of the frame side surface 26 that connect with the first electrode pad 23 and the second electrode pad 24 are indicated with diagonal lines in the same direction as the first electrode pad 23 and the second electrode pad 24, to prevent residue formation. The end face 45 of the convex part and the side faces 46 of both convex parts of the part 4 are indicated by hatching, and it is shown that the electrode material remains on the side face 26 of the frame, the end face 45 of the convex part, and the side faces 46 of both convex parts. There is.
However, after exposure, when exposing the main surfaces of the frame part 2 and the residue forming part 4, not only the main surfaces but also the surfaces perpendicular to the main surfaces (frame side surface 26, convex end surface 45, convex side surface 46) are exposed. , certain areas on both principal surfaces are also removed by overexposure.
Therefore, the starting point of the inclined surfaces 41 and 42 (the apex on the main surface side of the triangular shape forming the inclined surfaces 41 and 42 in FIG. 3(b)) is lower than the main surface (other main surfaces Even if the image is located on the side), it can be reliably divided by overexposure.
In this way, since the first electrode pad 23 and the second electrode pad 24 of the frame portion 2 are divided, exposure from an oblique direction is not necessary, and the number of steps can be reduced.
Note that the portions of the convex end surface 45 and both convex side surfaces 26 of the residue forming portion 4, which are shaded, are the remainder of the metal material formed in the electrode forming process described later, and are separated from the two systems of electrodes. has been done.

Next, a method for manufacturing the piezoelectric wafer 1 configured as described above will be explained.
FIG. 4 is a flowchart showing the manufacturing process of the piezoelectric wafer in the first embodiment.
First, in a wafer preparation step, a wafer on which the piezoelectric wafer 1 will be formed is prepared (step 12).
In this wafer preparation step, a wafer of a constant thickness is prepared by slicing crystal at a predetermined angle.

Next, the prepared wafer is subjected to an outline forming process in which the outline of the piezoelectric wafer 1 is formed (step 14).
In this outline forming step, the outline of the piezoelectric wafer 1 is formed by removing a part of the prepared wafer.
Specifically, a mask (outline mask) having a shape corresponding to the outer shape of the piezoelectric wafer 1 (excluding the inclined surfaces 41 and 42) is formed on both sides of the wafer by photolithography technology.
Thereafter, the wafer is wet-etched to selectively remove areas not masked by the external mask, thereby connecting the plurality of piezoelectric vibrating pieces 3 to the frame part 2 at the connecting part 21, as shown in FIG. At the same time, a planar external shape of the piezoelectric wafer 1 in which each residue forming part 4 is arranged is formed. At this time, inclined surfaces 41 and 42 as residue are also formed on both sides of the residue forming part 4 protruding from the frame part 2, although this is an area not masked by the external mask.
Next, each vibrating arm 7a, 7b of each piezoelectric vibrating piece 3 is etched to form grooves 72 on both main surfaces of each vibrating arm 7a, 7b.

Next, an electrode forming process is performed to form two systems of electrodes on the surface of the wafer whose outline has been formed (step 16).
(a) In this electrode forming step, a metal material that will become an electrode is formed into a film by vapor deposition or metal sputtering on the entire surface (main surface and side surfaces) of the wafer whose outer shape has first been formed. Regarding metal materials, a laminated film is formed by sputtering or the like for each layer, with a metal such as chromium as a base layer and a metal such as gold as a top layer.
(b) Then, two systems of electrodes (the first electrode pad 23 and the first excitation electrode 91, the first electrode pad 23 and the first excitation electrode 91, 2 electrode pad 24, second excitation electrode 92, routing electrode, etc.) and form a circuit pattern.
That is, after applying a resist film to the entire surface of the formed metal film, irradiation is applied to the entire surface from the main surface side using an electrode mask corresponding to the shape of the electrode pattern, and then development is performed. As a result, the resist films of the two systems of electrode portions remain in the regions corresponding to the electrode masks on the main surface, etc., and the resist films of the regions without the electrode masks and the inclined surfaces 41 and 42 are removed. The above exposure and development are performed on both principal surfaces.
Next, after removing the metal layer at the exposed portion by immersing it in an etching solution, the resist film coated on the surfaces of the two divided electrodes is removed.

Through each of the above steps, as shown in FIG. 2, the first excitation electrode 91 and the second excitation electrode 92 on the side surfaces of the vibrating arms 7a and 7b are divided.
Further, as shown in FIG. 3, the first electrode pad 23 and the second electrode pad 24 are divided at the main surface of the frame portion 2.
Further, the second electrode pad 24 and the first electrode pad 23 between adjacent piezoelectric vibrating pieces 3 are divided on the main surface, and are also divided on the inclined surfaces 41 and 42.
The second electrode pad 24 and the first electrode pad 23 on the frame side surface 26 are reliably formed by not only the normal exposure on the inclined surfaces 41 and 42 but also overexposure on the boundary portion with the main surface on the frame side surface 26. be divided. That is, in the outline forming process, even if the starting points of the slopes 41 and 42 to be formed are below the main surface (on the other main surface side), the divided regions due to normal exposure and the divided regions due to overexposure are different. Since the two electrode pads are connected, the second electrode pad 24 and the first electrode pad 23 on the frame side surface 26 can be reliably separated.
As described above, according to the present embodiment, the inclined surfaces 41 and 42 formed by the residue forming section 4 can eliminate the oblique exposure step.

Next, a weight metal film forming process is performed on the vibrating arms 7a and 7b of each piezoelectric vibrating piece 3 (step 18).
In this weight metal film forming step, a weight metal film for frequency adjustment is formed on the surfaces of widened portions 71a and 71b of each vibrating arm 7a and 7b.
This weight metal film can be formed, for example, by vapor deposition.
Note that the weight metal film may be formed simultaneously with each electrode in the electrode forming step (step 16).

Next, a frequency adjustment process is performed for each piezoelectric vibrating piece 3 (step 20).
In the frequency adjustment step, a predetermined driving voltage is applied between the first electrode pad 23 and the second electrode pad 24 connected to each piezoelectric vibrating piece 3 to vibrate each vibrating arm 7a, 7b of the piezoelectric vibrating piece 3. By this, the frequency of the piezoelectric vibrating piece 3 is adjusted.
Specifically, a probe of a measuring device or the like for applying a driving voltage is pressed against each of the first electrode pads 23 and second electrode pads 24 formed on the frame portion 2. In this state, a drive voltage is applied to each of the first excitation electrode 91 and second excitation electrode 92 to vibrate each vibrating arm 7a, 7b. Then, depending on the difference between the vibration frequency of each piezoelectric vibrating piece 3 and the target frequency, the weight metal film formed on the widened portions 71a and 71b is partially removed. As a result, the mass of each vibrating arm 7a, 7b changes, so that the vibration frequency of each vibrating arm 7a, 7b (frequency of piezoelectric vibrating piece 3) changes. Therefore, the frequency of the piezoelectric vibrating piece 3 can be brought closer to the target frequency.

Through each of the above steps, the piezoelectric wafer 1 of this embodiment shown in FIG. 1 is formed.
The next singulation step (step 22) is performed on the piezoelectric wafer 1 thus formed.
In this singulation step, each piezoelectric vibrating piece 3 connected to the frame portion 2 through the connecting portion 21 is cut and singulated.
Specifically, each piezoelectric vibrating piece 3 is bent relative to the frame portion 2 and cut at each connecting portion 21 . At this time, since the width of the connecting portion 21 is narrower on the base 8 side of the piezoelectric vibrating piece 3 than on the frame portion 2 side, the connecting portion 21 is cut on the base 8 side.
As described above, a plurality of piezoelectric vibrating pieces 3 can be manufactured at once from one wafer.

As described above, according to the piezoelectric wafer 1 of this embodiment, the residue forming portions 4 protruding from the frame portion 2 are formed between the plurality of piezoelectric vibrating pieces 3 arranged in parallel on the frame portion 2. Then, when forming the external shape of the piezoelectric wafer 1, since inclined surfaces 41 and 42 are also formed on both side surfaces of the frame section 2 and the residue forming section 4, the electrodes on the frame side surface 26 are formed using the inclined surfaces 41 and 42. It can be easily divided.
That is, of two adjacent piezoelectric vibrating pieces 3, the first electrode pad 23 is connected to the first excitation electrode 91 of one piezoelectric vibrating piece 3, and the second electrode pad 23 is connected to the second excitation electrode 92 of the other piezoelectric vibrating piece 3. To reliably divide the electrode pad 24 by exposing the main surface and the inclined surfaces 41 and 42 of the residue forming part 4 only from the main surface side (normal exposure and overexposure) without providing an oblique exposure process. I can do it.

Next, a second embodiment will be described.
FIG. 5 is an enlarged view showing the vicinity of the piezoelectric vibrating piece 3 of the piezoelectric wafer 1 in the second embodiment. FIG. 5(a) corresponds to FIG. 2(a) in the first embodiment. Moreover, FIGS. 5(b) and 5(c) are a further enlarged plan view and side view of the vicinity of the residue forming portion 5, and correspond to FIGS. 3(a) and 3(b).
In the first embodiment described, in order to divide the electrodes on the frame side surface 26, the residue forming portion 4 in which the inclined surfaces 41 and 42 are formed is formed in a shape that projects from the frame portion 2 in the direction of the piezoelectric vibrating reed 3.
On the other hand, in the piezoelectric wafer 1 of the second embodiment, a recessed residue forming portion 5 is formed in the frame portion 2, as shown in FIG. 5(a).

As shown in FIGS. 5(b) and 5(c), there are three surfaces in the recess of the residue forming portion 5: inclined surfaces 51 and 52 formed on the side surfaces 56 of the recess, and an inclined surface 53 formed on the bottom surface. is formed as a residue.
As shown in FIG. 5(b), the inclined surfaces 51 to 53 are formed on both sides of the frame portion 2 from both main surfaces toward the center in the thickness direction.
In the piezoelectric wafer 1 of the second embodiment, as in the first embodiment, the electrodes on the frame side surface 26 of the frame portion 2 can be easily divided by the inclined surfaces 51 to 53.
That is, of two adjacent piezoelectric vibrating pieces 3, the first electrode pad 23 is connected to the first excitation electrode 91 of one piezoelectric vibrating piece 3, and the second electrode pad 23 is connected to the second excitation electrode 92 of the other piezoelectric vibrating piece 3. The electrode pad 24 can be reliably divided by exposing the main surface and the inclined surfaces 51 to 53 of the residue forming portion 5 (normal exposure and overexposure) without providing an oblique exposure step.

FIG. 6 is an explanatory diagram showing a modification of the piezoelectric wafer 1.
In the first and second embodiments described above, the case where the first electrode pad 23 and the second electrode pad 24 corresponding to all the piezoelectric vibrating pieces 3 are divided is explained.
On the other hand, in a modified example of the piezoelectric wafer 1, as shown in FIG. 6, a plurality of first electrode pads 23 are electrically connected to each other. Here, the number of first electrode pads 23 to be connected may be two or more. In the process of frequency adjustment, it is preferable to connect the first electrode pads 23 for each frame portion 2 in the X direction to which the piezoelectric vibrating pieces 3 are connected, or to connect all the first electrode pads 23.
By electrically connecting the plurality of first electrode pads 23 in this manner, one of the probes of the measuring instrument can be fixed to any one of the first electrode pads 23 during frequency adjustment, while the other The frequency can be measured and adjusted while moving the probe for each second electrode pad 24.

Although FIG. 6 describes the case where a plurality of first electrode pads 23 are electrically connected, a plurality of second electrode pads 24 may be electrically connected.
Further, this modification can be applied not only to the first embodiment but also to the second embodiment.

Furthermore, in the described embodiments and modified examples, a so-called side arm type piezoelectric vibrating piece 3 is provided, in which support arms 9a and 9b for mounting are formed on both sides of the vibrating arms 7a and 7b from the base 8. Although the piezoelectric wafer 1 has been described, it is also possible to arrange various other types of piezoelectric vibrating pieces.
For example, it is also possible to use a piezoelectric wafer 1 in which a so-called cantilever type piezoelectric vibrating piece is disposed, in which there is no support arm and two systems of mounting electrodes for mounting are formed on the base 8.
Further, a support part is formed between the base 8 and both vibrating arms 7a and 7b, and a so-called center arm type piezoelectric vibrating piece, in which two systems of mounting electrodes for mounting are formed, is disposed on this support part. It is also possible to use a piezoelectric wafer 1 that has been provided.
Furthermore, in addition to the tuning fork type piezoelectric vibrating piece, various other fixed piezoelectric vibrating pieces, such as an inverted mesa type AT-cut crystal vibrating piece, can be applied to a piezoelectric wafer that is connected to a thick plate portion with a connecting leg. is also possible.

1 Piezoelectric wafer 2 Frame section 21 Connection section (connection section)
23 First electrode pad 24 Second electrode pad 26 Frame side surface 3 Piezoelectric vibrating piece 4, 5 Residue forming section 41, 42, 51, 52, 53 Inclined surface 45 Convex end surface 46 Convex side surface 56 Concave side surface 7a, 7b Vibrating arm Parts 71a, 71b Widened parts 72a, 72b Groove parts 8 Base parts 9a, 9b Support arm parts 91 First excitation electrode 92 Second excitation electrode

Claims (5)

A frame part,
a piezoelectric vibrating piece having a plurality of vibrating arms connected to the frame portion in parallel;
a first excitation electrode and a second excitation electrode that vibrate the vibrating arm portion, which are formed on each of the piezoelectric vibrating pieces;
A first electrode pad electrically connected to the first excitation electrode and formed on the frame portion corresponding to each of the piezoelectric vibrating pieces; and a first electrode pad electrically connected to the second excitation electrode. a second electrode pad;
a residue forming portion formed between adjacent connection portions that connect the piezoelectric vibrating piece to the frame portion;
an inclined surface formed as a residue by the residue forming section,
The first electrode pad formed corresponding to one of the two adjacent piezoelectric vibrating pieces and the second electrode pad formed corresponding to the other piezoelectric vibrating piece are arranged in the frame portion. divided by a main surface and an inclined surface formed as the residue,
A piezoelectric wafer characterized by: The residue forming part is formed in a convex shape in a direction in which the piezoelectric vibrating piece is formed with respect to the frame part,
The inclined surface is formed between both sides of the frame portion and the convex residue forming portion,
The piezoelectric wafer according to claim 1, characterized in that: The residue forming portion is formed in a concave shape recessed in a direction opposite to a direction in which the piezoelectric vibrating piece is formed with respect to the frame portion,
The inclined surface is formed on both side surfaces and the bottom surface of the concave shape,
The piezoelectric wafer according to claim 1, characterized in that: A method for manufacturing a piezoelectric wafer according to claim 1, claim 2, or claim 3,
a wafer preparation process for preparing the wafer;
an outer shape forming step of forming an outer shape of the piezoelectric wafer from the prepared wafer;
After forming a metal material on the surface of the wafer formed in the outer shape forming step , a first system of the first excitation electrode and the first electrode pad, and the second excitation electrode are formed by photolithography on the metal material. and an electrode forming step of forming two systems of electrodes of the second system of the second electrode pad;
a frequency adjustment step of applying a driving voltage from the first electrode pad and the second electrode pad to adjust the frequency of each of the piezoelectric vibrating pieces;
In the electrode forming step, in photolithography for the metal material, an electrode mask having an electrode pattern shape corresponding to the two systems of electrodes is used, and exposure is performed from the main surface side, thereby forming the first system and the second system. divide the system electrodes,
A method for manufacturing a piezoelectric wafer, characterized by: A method for manufacturing a piezoelectric wafer according to claim 4,
a singulation step of cutting each of the plurality of piezoelectric vibrating pieces connected to the frame portion from the piezoelectric wafer manufactured by the piezoelectric wafer manufacturing method ;
A method for manufacturing a piezoelectric vibrating piece, characterized by comprising:

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