JP2012160872A - Piezoelectric device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device which reduces a short circuit between conductive adhesives coated on a pair of piezoelectric oscillation element mounting pads.SOLUTION: A piezoelectric device of the present invention comprises: a substrate part; an element mounting member provided with a first frame part and a second frame on one principal surface of the substrate part and formed of a recess space; a pair of piezoelectric oscillation element mounting pads provided in the recess space; a tuning-fork type flexural crystal oscillation element mounted on the pair of piezoelectric oscillation element mounting pads, and including a base part, two oscillation arm parts extending from lateral faces of the base part in the same direction, and balancing arm parts extending from the lateral faces of the base part located between the two oscillation arm parts; a lid hermetically sealing the recess space; and a groove provided between the piezoelectric oscillation element mounting pads on a principal surface of the first frame part. A relationship between a length W1 in a depth direction of the groove and a thickness W2 of the first frame part is represented as 0.4≤W1/W2≤0.9.

Description

  The present invention relates to a piezoelectric device used for an electronic apparatus and the like and manufacturing thereof.

Conventional piezoelectric vibrators are mainly composed of, for example, an element mounting member, a tuning fork-type bent quartz crystal vibration element, and a lid (see Patent Document 1).
The element mounting member includes a substrate part, a first frame part, and a second frame part.
The element mounting member is provided in a state in which the first frame portion and the second frame portion are stacked on one main surface of the substrate portion to form a recessed space.
On one main surface of the first frame exposed in the recess space, two pairs of piezoelectric vibration element mounting pads are provided, and a tuning fork type crystal vibration element is mounted.
The substrate portion has a laminated structure, and an inner layer of the substrate portion is provided with a wiring pattern (not shown). With this wiring pattern, the piezoelectric vibration element mounting pad is connected to an external connection electrode terminal provided on the other main surface of the substrate portion of the element mounting member.
In addition, a sealing conductor pattern is provided on the main surface of the second frame portion.
The sealing conductor pattern of the second frame portion of the element mounting member that surrounds the tuning fork-type bending crystal resonator element is covered with a metal lid and bonded. Thereby, the recessed space is hermetically sealed.

Such a tuning-fork type bending crystal resonator element includes a base portion and two flat plate-shaped vibrating arm portions extending in the same direction from the side surface of the base portion.
On the surface of the base and the vibrating arm, a connection electrode, an excitation electrode, and a frequency adjusting metal film that are electrically connected to the piezoelectric vibration element mounting pad of the element mounting member are formed.
This tuning fork-type bending crystal resonator element is cantilevered by fixing a connection electrode to a piezoelectric resonator element mounting pad with a conductive adhesive. In the vibrating arm portion at this time, an end portion facing the side opposite to the base portion is a tip portion.

  In addition, the piezoelectric device sheet substrate is provided with a plurality of element mounting members arranged in a matrix. A plurality of piezoelectric devices can be obtained by dividing the element mounting member into individual pieces.

JP 2008-301297 A

  However, in the conventional piezoelectric device, when a conductive adhesive is applied to each of the two pairs of piezoelectric vibration element mounting pads and the piezoelectric vibration elements are mounted, the conductive adhesive applied to each of the piezoelectric vibration element mounting pads. There was a problem that the two contact each other and a pair of two piezoelectric vibration element mounting pads short-circuited. As a result, the conventional method for manufacturing a piezoelectric device has a problem in that productivity decreases.

  The present invention has been made in view of the above-described problems, and provides a piezoelectric device and a method for manufacturing the same that reduce short-circuiting of conductive adhesives applied to two pairs of piezoelectric vibration element mounting pads. Let it be an issue.

  In the piezoelectric device of the present invention, the piezoelectric device of the present invention has a substrate portion, and a first frame portion and a second frame portion are provided on one main surface of the substrate portion, so that a recessed space is formed. An element mounting member, two pairs of piezoelectric vibration element mounting pads provided on the main surface of the first frame exposed in the recessed space, and a piezoelectric element mounted on the two pairs of piezoelectric vibration element mounting pads A vibration element, a lid for hermetically sealing the recessed space, and a groove provided between the piezoelectric vibration element mounting pads on the main surface of the first frame, and the length W1 in the depth direction of the groove. And the thickness W2 of the first frame portion is 0.4 ≦ W1 / W2 ≦ 0.9.

  The relationship between the length L1 in the short side direction of the groove and the length L2 between the two pairs of piezoelectric vibration element mounting pads is 0.3 ≦ L1 / L3 ≦ 0.8. To do.

  The piezoelectric device manufacturing method of the present invention includes a substrate portion and a first frame portion and a second frame portion provided on one main surface of the substrate portion to form a recessed space, and the inner space of the recessed portion is formed. A laser is provided between the piezoelectric vibration element mounting pads on the main surface of the first frame portion of an element mounting member in which two pairs of piezoelectric vibration element mounting pads are provided on the main surface of the first frame portion exposed to the surface. A groove forming step of forming a groove by machining or sandblasting, a piezoelectric vibrating element mounting step of mounting a piezoelectric vibrating element on a pair of piezoelectric vibrating element mounting pads provided in a recessed space of the element mounting member, and a piezoelectric vibration A lid member joining step for joining the lid member to the element mounting member so as to hermetically seal the element.

  According to the piezoelectric device of the present invention, the relationship between the length W1 in the depth direction of the groove provided between the piezoelectric vibration element mounting pads on the main surface of the first frame and the thickness W2 of the first frame. However, when 0.4 ≦ W1 / W2 ≦ 0.9, a conductive adhesive is applied to each of the two pairs of piezoelectric vibration element mounting pads, and the conductive adhesive is applied when mounting the piezoelectric vibration elements. Even if it flows out, since the conductive adhesive flows out along the main surface of the first frame part and the wall surface of the groove part, the distance is increased by the length in the depth direction of the groove part. The conductive adhesive applied to the pads does not contact each other, and a short circuit between two pairs of piezoelectric vibration element mounting pads can be reduced.

  According to the piezoelectric device of the present invention, the relationship between the length L1 in the short side direction of the groove and the length L3 between the two pairs of piezoelectric vibration element mounting pads is 0.3 ≦ L1 / L3 ≦. When 0.8, the conductive adhesive is applied to each of the two pairs of piezoelectric vibration element mounting pads, and even when the conductive adhesive flows out when mounting the piezoelectric vibration elements, the groove portion is not conductive adhesive. Therefore, the conductive adhesive applied to each piezoelectric vibration element mounting pad does not come into contact with each other, and a short circuit between two pairs of piezoelectric vibration element mounting pads can be reduced.

  According to the method for manufacturing a piezoelectric device of the present invention, the first element mounting member in which two pairs of piezoelectric vibration element mounting pads are provided on the main surface of the first frame exposed in the recess space. Since the groove portion is formed by using laser processing or sandblasting between the piezoelectric vibration element mounting pads on the main surface of the frame portion, even if the conductive adhesive flows out when mounting the piezoelectric vibration element, the edge of the groove portion Since the portion is formed so as to rise, the conductive adhesive is dammed at the edge portion. Therefore, the conductive adhesive applied to each piezoelectric vibration element mounting pad does not come into contact with each other, and the short circuit between two pairs of piezoelectric vibration element mounting pads is reduced, thereby improving the productivity of the piezoelectric device. Can do.

1 is an exploded perspective view showing a piezoelectric device according to an embodiment of the present invention. (A) is AA sectional drawing of FIG. 1, (b) is BB sectional drawing of FIG. (A) is a top view which shows the state which removed the cover member of the piezoelectric device which concerns on embodiment of this invention, (b) shows the state of the element mounting member of the piezoelectric device which concerns on embodiment of this invention. It is a top view. It is a top view which shows the sheet | seat board | substrate preparation process for piezoelectric devices by the manufacturing method of the piezoelectric device which concerns on embodiment of this invention. It is a top view which shows an element mounting member singulation process with the manufacturing method of the piezoelectric device which concerns on embodiment of this invention. It is a top view which shows a piezoelectric vibration element mounting process with the manufacturing method of the piezoelectric device which concerns on embodiment of this invention. It is a top view which shows a cover member joining process with the manufacturing method of the piezoelectric device which concerns on embodiment of this invention. It is a graph which shows the relationship between the length of the depth direction of the groove part of the element mounting member which comprises the piezoelectric device of this invention, and the thickness of a 1st frame part, and the yield with a short circuit. It is a graph which shows the relationship between the length of the depth direction of the groove part of the element mounting member which comprises the piezoelectric device of this invention, and the thickness of the 1st frame part, and the yield accompanying the fluctuation | variation of an oscillation frequency. It is a graph which shows the relationship between the length of the short side direction of the groove part of the element mounting member which comprises the piezoelectric device of this invention, the length between piezoelectric vibration element mounting pads, and the yield with a short circuit. The relationship between the length L1 in the short side direction of the groove portion of the element mounting member constituting the piezoelectric device of the present invention and the length between two pairs of piezoelectric vibration element mounting pads and the yield due to peeling of the piezoelectric vibration element. It is a graph to show.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. A case of a tuning-fork type bending crystal vibrating element using quartz as a piezoelectric vibrating element will be described. In addition, the illustrated dimensions are partially exaggerated.

The embodiment of the present invention describes a piezoelectric vibrator 300 that is one example of a piezoelectric device.
As shown in FIGS. 1 and 2, the piezoelectric vibrator 300 mainly includes an element mounting member 210, a piezoelectric vibration element 100, and a lid body 230. In the piezoelectric vibrator 300, the piezoelectric vibration element 100 is mounted in a recessed space K 1 formed in the element mounting member 210. The recessed space K1 is hermetically sealed by the lid 230.

(Tuning fork type bending crystal resonator)
A tuning fork-type bending crystal resonator element 100, which is one example of a piezoelectric resonator element, will be described.
As shown in FIGS. 1 and 2, the tuning-fork type bending crystal resonator element 100 includes a crystal piece 110, excitation electrodes 121a, 121b, 122a and 122b provided on the surface of the crystal piece 110, and a connection electrode 123a. And 123b, frequency adjusting metal films 124a and 124b, and conductive wiring patterns 125 and 126.

As shown in FIGS. 1 and 2, the crystal piece 110 includes a base portion 111 and a vibrating arm portion 112, and the vibrating arm portion 112 includes a first vibrating arm portion 112a and a second vibrating arm portion 112b.
When the base 111 is an orthogonal coordinate system in which the electrical axis is the X axis, the mechanical axis is the Y axis, and the optical axis is the Z axis as the crystal axis direction, the base 111 is within a range of −5 ° to + 5 ° around the X axis. This is a flat plate having a substantially rectangular shape in a plan view in which the direction of the rotated Z ′ axis is the thickness direction.
The first vibrating arm portion 112a and the second vibrating arm portion 112b extend from one side of the base portion 111 in parallel to the Y′-axis direction.
Such a crystal piece 110 has a tuning fork shape in which the base portion 111 and the vibrating arm portions 112a and 112b are integrated, and is manufactured by a photolithography technique and a chemical etching technique.

Moreover, as shown in FIG. 1, the excitation electrode 122a is provided on the front and back main surfaces of the first vibrating arm portion 112a. The excitation electrode 122b is provided on both opposing side surfaces of the first vibrating arm portion 112a.
The frequency adjusting metal film 124a is provided on the front main surface and the front end of the side surface of the first vibrating arm portion 112a.
The connection electrode 123 a is provided on the front and back main surfaces of the base 111 on the first vibrating arm portion 112 a side of the base 111.

As shown in FIG. 1, the excitation electrode 121a is provided on the front and back main surfaces of the second vibrating arm portion 112b. The excitation electrode 121b is provided on both opposite side surfaces of the second vibrating arm portion 112b.
The frequency adjusting metal film 124b is provided on the front main surface and the front end portions of both side surfaces of the second vibrating arm portion 112b.
The connection electrode 123 b is provided on the front and back main surfaces of the base 111 on the second vibrating arm 112 b side of the base 111.

  The tuning-fork type bending crystal resonator element 100 can adjust the vibration frequency value to a desired value by increasing / decreasing the amount of the metal constituting the frequency adjusting metal films 124a and 124b.

As shown in FIG. 2, the excitation electrodes 121a and 122b, the frequency adjusting metal film 124a, and the connection electrode 123a are electrically connected by, for example, a conductive wiring pattern 125 provided on the surface of the crystal base plate 110. ing.
The connection electrode 123 a is electrically connected to the excitation electrode 121 a through a conductive wiring pattern 125 provided on the base 111. The connection electrode 123a is electrically connected to the excitation electrode 122b.

Further, as shown in FIG. 2, the excitation electrodes 121b and 122a, the frequency adjusting metal film 124b, and the connection electrode 123b are electrically connected by, for example, a conductive wiring pattern 126 provided on the surface of the crystal piece 110. is doing.
The connection electrode 123b is electrically connected to the excitation electrode 121b and the frequency adjusting metal film 124b. In addition, the conductive wiring pattern 126 provided on the front main surface of the base 111 is electrically connected to the excitation electrode 122a and the excitation electrode 121b.

  The excitation electrodes 121a, 121b, 122a and 122b, the connection electrodes 123a and 123b, the frequency adjusting metal films 124a and 124b, and the conductive wiring patterns 125 and 126 are, for example, a Cr layer as a base metal. , And an Au layer provided on the base metal.

  When this tuning fork type bending crystal resonator element 100 is vibrated, an alternating voltage is applied to the connection electrodes 123a and 123b. When an electrical state after application is instantaneously captured, the excitation electrode 121b of the second vibrating arm portion 112b has a + (plus) potential, the excitation electrode 121a has a-(minus) potential, and changes from + to-. An electric field is generated. On the other hand, the excitation electrode of the first vibrating arm portion 112a at this time has a polarity opposite to the polarity generated in the exciting electrode of the second vibrating arm portion 112b. These applied electric fields cause an expansion / contraction phenomenon in the first vibrating arm portion 112a and the second vibrating arm portion 112b, and a bending vibration having a resonance frequency set in each vibrating arm portion 112 is obtained.

(Element mounting member)
In addition, as shown in FIGS. 1 to 2, the element mounting member 210 is mainly composed of a substrate part 210 a, a first frame part 210 b, and a second frame part 210 c.
In the element mounting member 210, a first frame portion 210b and a second frame portion 210c are provided on one main surface of the substrate portion 210a to form a recessed space K1.
An annular sealing conductor pattern 212 is formed on the entire circumference of the opening-side top surface of the second frame portion 210c surrounding the recessed space K1 of the element mounting member 210.
Two pairs of piezoelectric vibration element mounting pads 211 are provided on one main surface of the first frame 210b exposed in the recessed space K1.
External connection electrode terminals G are provided at both ends of the other main surface of the substrate portion 210 a of the element mounting member 210.
A wiring pattern (not shown) or the like is provided on the inner layer of the substrate part 210a, and connects a predetermined piezoelectric vibration element mounting pad 211 and an external connection electrode terminal G (see FIG. 2).

As shown in FIG. 2B, a groove 214 is formed between two pairs of piezoelectric vibration element mounting pads 211 provided on one main surface of the first frame 210b exposed in the recess space K1. Is provided.
For example, when the length in the long side direction of the element mounting member 210 constituting the piezoelectric device 300 is 2.0 mm and the length in the short side direction is 0.8 mm, FIG. The length L1 in the short side direction of the groove 214 shown is, for example, 30 to 160 μm, and the length L2 in the long side direction of the groove 214 is, for example, 200 to 300 μm. Moreover, the depth W1 of the groove part 214 shown in FIG.2 (b) is 40-90 micrometers, for example.
Moreover, thickness W2 of the 1st frame part 210b of the element mounting member 210 shown in FIG.2 (b) is 100-200 micrometers, for example.
A length L3 between the two pairs of piezoelectric vibration element mounting pads 211 shown in FIG. 3B is, for example, 100 to 200 μm.
Further, when the groove 214 is formed, the edge of the groove 214 is formed so as to rise.
The edge portion of the groove portion 214 is a portion provided on the main surface of the first frame portion 210b.

The relationship between the length W1 in the depth direction of the groove 214 and the thickness W2 of the first frame 210b is 0.4 ≦ W1 / W2 ≦ 0.9.
As shown in FIG. 8, when the value of W1 / W2 is smaller than 0.4, the conductive adhesive DS applied to the piezoelectric vibration element mounting pad 211 is applied to the adjacent piezoelectric vibration element mounting pad 211. As a result, the piezoelectric vibration element mounting pad 211 was short-circuited in contact with the adhesive adhesive DS.
Further, as shown in FIG. 8, when the value of W1 / W2 is 0.1, the result of the yield due to the short circuit between the piezoelectric vibration element mounting pads 211 is 28%. That is, when the value of W1 / W2 is 0.1, a result that the defect rate due to the short circuit between the piezoelectric vibration element mounting pads 211 is 72% is obtained.
As shown in FIG. 9, when the value of W1 / W2 is larger than 0.9, the heat is applied to form the groove 214 by laser processing or sand blasting, and the first frame portion 210b and the substrate portion 210a. As a result, a crack was generated between the two, and the hermetic sealing in the concave space K1 could not be maintained, and the oscillation frequency fluctuated. Further, when the value of W1 / W2 is 0.95, a result that the yield due to the oscillation frequency fluctuation is 90% is obtained. That is, when the value of W1 / W2 is 0.95, a result that the defect rate accompanying the oscillation frequency fluctuation is 10% is obtained.
Thus, the relationship between the depth W1 of the groove 214 provided between the piezoelectric vibration element mounting pads 211 on the main surface of the first frame 210b and the thickness W2 of the first frame 210b is as follows. When 0.4 ≦ W1 / W2 ≦ 0.9, the conductive adhesive DS is applied to each of the two pairs of piezoelectric vibration element mounting pads 211, and the tuning fork type bending crystal vibration element 100 is mounted. Even if the conductive adhesive DS flows out, the conductive adhesive DS flows out along the main surface of the first frame part 210b and the wall surface of the groove part 214, so that the distance is increased by the length of the groove part 214 in the depth direction. As a result, the conductive adhesives DS applied to the respective piezoelectric vibration element mounting pads 211 do not contact each other, and a short circuit between the two pairs of piezoelectric vibration element mounting pads 211 can be reduced.
The wall surface of the groove portion 214 is a surface formed in the thickness direction of the first frame portion 210b formed in the groove portion 214.

The relationship between the length L1 of the groove 214 in the short side direction and the length L3 between the two pairs of piezoelectric vibration element mounting pads 211 is 0.3 ≦ L1 / L3 ≦ 0.8. Is provided.
As shown in FIG. 10, when the value of L1 / L3 is smaller than 0.3, the conductive adhesive DS applied to the piezoelectric vibration element mounting pad 211 is electrically conductive applied to the adjacent piezoelectric vibration element mounting pad 211. As a result, a contact between the piezoelectric adhesive DS and a short circuit between the piezoelectric vibration element mounting pads 211 was obtained. Further, as shown in FIG. 10, when the value of L1 / L3 is 0.1, the result is that the yield due to the short circuit between the piezoelectric vibration element mounting pads becomes 36%. That is, when the value of L1 / L3 is 0.1, the result is that the defect rate due to a short circuit between the piezoelectric vibration element mounting pads is 64%.
Further, as shown in FIG. 11, when the value of L1 / L3 is larger than 0.8, the groove 214 is formed by laser processing and sand blast processing, and therefore the piezoelectric vibration element mounting pad 211 is formed by laser processing or sand blast processing. As a result, the area of the piezoelectric vibration element mounting pad 211 is reduced. As a result, the bonding strength of the conductive adhesive DS was lowered, and the tuning fork-type bending crystal resonator element 100 was peeled off from the piezoelectric resonator element mounting pad 211. In addition, as shown in FIG. 11, when the value of L1 / L3 is 0.9, the yield resulting from the peeling of the tuning fork-type bending crystal resonator element 100 is 80%. That is, when the value of L1 / L3 is 0.9, a result is obtained that the defect rate associated with peeling of the tuning fork type bending crystal resonator element 100 becomes 20%.
Thus, the relationship between the length L1 in the short side direction of the groove 214 and the length L3 between the two pairs of piezoelectric vibration element mounting pads 211 is 0.3 ≦ L1 / L3 ≦ 0.8. Thus, even when the conductive adhesive DS is applied to each of the two pairs of piezoelectric vibration element mounting pads 211 and the conductive adhesive DS flows when the piezoelectric vibration element 100 is mounted, the groove 214 is formed into the conductive adhesive. Since it does not overflow with DS, the conductive adhesive DS applied to each piezoelectric vibration element mounting pad 211 does not contact each other, and a short circuit between two pairs of piezoelectric vibration element mounting pads 211 can be reduced. it can.

As shown in FIGS. 2 and 3, the lid 230 is arranged and joined on the sealing conductor pattern 212 of the element mounting member 210 so as to cover the opening of the first recessed space K <b> 1. The lid 230 is provided with a sealing member 231 at a location facing the sealing conductor pattern 212.
Further, such a sealing member 231 can relieve unevenness on the surface of the sealing conductor pattern 212 and prevent deterioration in airtightness.

  Further, the lid 230 disposed on the element mounting member 210 is manufactured by adopting a conventionally known metal processing method and shaping a metal such as 42 alloy into a predetermined shape. A nickel (Ni) layer is formed on the upper surface of the lid 230, and a silver brazing layer that is a sealing member 231 is formed on the upper surface of the nickel (Ni) layer at least at a location facing the sealing conductor pattern 212. The The thickness of the silver wax layer is 10 μm to 40 μm.

  The conductive adhesive DS contains conductive powder as a conductive filler in a binder such as silicone resin. Examples of the conductive powder include aluminum (Al), molybdenum (Mo), tungsten ( W), platinum (Pt), palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or any combination thereof is used. Yes.

  In addition, when the element mounting member 210 is made of alumina ceramic, a piezoelectric vibration element mounting pad 211 and a seal are formed on the surface of a ceramic green sheet obtained by adding and mixing an appropriate organic solvent or the like to a predetermined ceramic material powder. Conductor paste serving as a conductor pattern 212, electrode terminals G for external connection, etc., and a conductor serving as a via conductor in a through hole (not shown) previously punched by punching a ceramic green sheet The paste is applied by conventionally known screen printing, and a plurality of the pastes are laminated and press-molded, and then fired at a high temperature.

  According to the piezoelectric device 300 of the present invention, the length W1 in the depth direction of the groove 214 provided between the piezoelectric vibration element mounting pads 211 on the main surface of the first frame 210b and the first frame 210b. When the relationship with the thickness W2 is 0.4 ≦ W1 / W2 ≦ 0.9, the conductive adhesive DS is applied to each of the two pairs of piezoelectric vibration element mounting pads 211, and the piezoelectric vibration element 100 is mounted. Even when the conductive adhesive DS flows out, the conductive adhesive DS flows out along the main surface of the first frame portion 210b and the wall surface of the groove portion 214. Therefore, the length of the groove portion 214 in the depth direction is the same. Since the distance becomes longer, the conductive adhesive DS applied to each piezoelectric vibration element mounting pad 211 does not contact each other, and a short circuit between the pair of piezoelectric vibration element mounting pads 211 can be reduced. .

  Further, according to the piezoelectric device 200 of the present invention, the relationship between the length L1 of the groove 214 in the short side direction and the length L3 between the two pairs of piezoelectric vibration element mounting pads 211 is 0.3 ≦ L1. When /L3≦0.8, the conductive adhesive DS is applied to each of the two pairs of piezoelectric vibration element mounting pads 211, and the conductive adhesive DS flows out when the piezoelectric vibration element 100 is mounted. Since the groove 214 does not overflow with the conductive adhesive DS, the conductive adhesives DS applied to the respective piezoelectric vibration element mounting pads 211 do not contact each other, and two pairs of piezoelectric vibration element mounting pads 211 are provided. The short circuit between them can be reduced.

  Next, a method for manufacturing a piezoelectric device according to an embodiment of the present invention will be described with reference to FIGS.

(Groove formation process)
As shown in FIG. 5, in the groove forming step, the substrate portion 210a and the first frame portion 210b and the second frame portion 210c are provided on one main surface of the substrate portion 210a, and the recessed space K1 is formed. The first frame portion 210a of the element mounting member 210 that is formed and has two pairs of piezoelectric vibration element mounting pads 211 provided on the main surface of the first frame portion 210a that is exposed in the recessed space K1. In this step, a groove 214 is formed by laser processing or sand blasting between the piezoelectric vibration element mounting pads 211 on the main surface.

The element mounting member 210 is provided with two pairs of piezoelectric vibration element mounting pads 211 on the main surface of the first frame exposed in the recess space K1. A groove 214 is formed between the two piezoelectric vibration element mounting pads 211 by laser processing or sand blast processing.
For example, when the length in the long side direction of the element mounting member 210 constituting the piezoelectric device 300 is 2.0 mm and the length in the short side direction is 0.8 mm, FIG. The length L1 in the short side direction of the groove 214 shown is, for example, 30 to 160 μm, and the length L2 in the long side direction of the groove 214 is, for example, 200 to 300 μm. Moreover, the depth W1 of the groove part 214 shown in FIG.2 (b) is 40-90 micrometers, for example.
Moreover, thickness W2 of the 1st frame part 210b of the element mounting member 210 shown in FIG.2 (b) is 100-200 micrometers, for example.
A length L3 between the two pairs of piezoelectric vibration element mounting pads 211 shown in FIG. 3B is, for example, 100 to 200 μm.

As the laser processing, for example, a carbon dioxide laser, a YAG laser, a YVO4 laser, a semiconductor laser, an excimer laser, or the like is used.
For example, in the case of a YVO4 laser, a laser whose third wavelength is 300 nm to 400 nm is used.
As sandblasting, for example, it is processed by spraying abrasive grains of 10 to 15 μm.
When the groove portion 214 is formed by using this laser processing and sand blast processing, the edge portion of the groove portion 214 is formed so as to rise.
The edge portion of the groove portion 214 is a portion provided on the main surface of the first frame portion 210b.

  Further, for example, as shown in FIG. 4, the element mounting member 210 and the surplus portion 220 in which the recessed space K1 is formed by the substrate portion 210a, the first frame portion 210b, and the second frame portion 210c are alternately arranged. The sheet substrate 200 for piezoelectric devices constituted by having a plurality is used.

As shown in FIG. 4, the surplus part 220 is provided with two or more so that the element mounting member 210 mentioned later may be adjoined.
The width of the surplus portion 220 is, for example, 50 to 150 μm, and is the same length as the thickness of a dicer (not shown) when the dicing method is used. That is, the surplus portion 220 is deleted when the element mounting member 210 is separated.

The piezoelectric device sheet substrate 200 is cut by dicing using a dicer or cutting with a laser, and the piezoelectric device sheet substrate 200 is divided into individual element mounting members 210. Thereby, the several element mounting member 210 is obtained simultaneously.
Examples of the dicer include a disk-shaped electroformed blade in which diamond abrasive grains and the like are fixed by electroforming, and a resin blade using an insulating resin such as an epoxy resin as a binder.
As the laser, a laser having a third harmonic of a YAG laser and a wavelength of, for example, 300 to 400 nm is used.

(Piezoelectric vibrator mounting process)
As shown in FIG. 6, the piezoelectric vibration element mounting step is a step of mounting the piezoelectric vibration element 100 on the piezoelectric vibration element mounting pad 211 provided in the recessed space K <b> 1 of the element mounting member 210.
Two pairs of piezoelectric vibration element mounting pads 211 are provided on the substrate portion 110a in the concave space K1 of the element mounting member 210, and a conductive adhesive DS is applied onto the piezoelectric vibration element mounting pads 211. A piezoelectric electrode is formed in such a manner that an extraction electrode 124 (see FIG. 3) extracted from the excitation electrode 122 formed on the surface of the tuning fork-type bending quartz crystal vibration element 100 is attached to the conductive adhesive DS applied to the piezoelectric vibration element mounting pad 211. The vibration element 100 is mounted.
In a state where the element mounting member 210 is housed in an internal space of a curing annealing furnace in an air atmosphere or a nitrogen atmosphere, the conductive adhesive DS is heated and cured, and the piezoelectric vibration element mounting pad 211 and the tuning fork type bent quartz crystal are cured. The vibration element 100 is conductively fixed.
The heat curing means that the conductive adhesive DS is cured by heating.

The furnace body has an internal space and serves to store the element mounting member 210.
The heating unit plays a role of heating the internal space to a predetermined temperature. For example, a halogen lamp or a xenon lamp is used as the heating unit.
The supply unit serves to supply gas to the internal space. For example, nitrogen is used as the gas.
The control unit controls the temperature and oxygen concentration of the internal space of the furnace body, the heating rate of the heating unit, and the gas supply amount of the supply unit.

(Cover member joining process)
As shown in FIG. 7, the lid member joining step is a step of joining the lid member 230 to the element mounting member 210 so as to hermetically seal the piezoelectric vibration element 100.
The lid member 230 is made of, for example, an Fe—Ni alloy (42 alloy) or an Fe—Ni—Co alloy (Kovar), and the tuning fork type quartz crystal vibrating element 120 is hermetically sealed in a nitrogen gas atmosphere or a vacuum atmosphere. Used when
Specifically, the lid member 230 is placed on the second frame portion 210c of the element mounting member 210 in a nitrogen gas atmosphere or a vacuum atmosphere, and is provided on the main surface of the second frame portion 210c. The roller electrode (not shown) of a seam welder (not shown) is brought into contact with the lid member 230 so that the sealing conductor pattern 212 and the sealing member 231 provided on the lid member 230 are welded. By moving along the outer edge of the lid member 230 while supplying power to the roller electrode, the roller electrode is joined to the sealing conductor pattern 212 provided on the main surface of the second frame portion 210c.

  According to the method for manufacturing the piezoelectric device 300 of the present invention, an element mounting member in which two pairs of piezoelectric vibration element mounting pads 211 are provided on the main surface of the first frame portion 210a exposed in the recess space K1. Since the groove 214 is formed by irradiating a laser between the piezoelectric vibration element mounting pads 211 on the main surface of the first frame 210a of 210, the conductive adhesive DS is mounted when mounting the piezoelectric vibration element 100. Since the edge of the groove 214 is formed so as to rise even if the liquid flows out, the conductive adhesive DS is blocked by the raised edge. Therefore, the conductive adhesives DS applied to the respective piezoelectric vibration element mounting pads 211 do not come into contact with each other, and a short circuit between the two pairs of piezoelectric vibration element mounting pads 211 is reduced. Can be improved.

  Further, according to the method of manufacturing the piezoelectric device 300 of the present invention, the groove portion 214 is formed by laser or sand blasting, and therefore the length L1 in the short side direction of the groove portion 214 can be adjusted. The area of the piezoelectric vibration element mounting pad 211 can be maintained even when the piezoelectric vibration element mounting pad 211 enters directly below the second frame portion 210b due to stacking deviation. it can. Therefore, since the bonding strength between the conductive adhesive DS and the piezoelectric vibration element mounting pad 211 can be maintained, the peeling of the piezoelectric vibration element 100 from the piezoelectric vibration element mounting pad 211 can be reduced.

In addition, this invention is not limited to the said embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
For example, in the above-described embodiment, the case where quartz is used as the piezoelectric material constituting the piezoelectric vibration element has been described. However, as other piezoelectric materials, lithium niobate, lithium tantalate, or piezoelectric ceramics is used as the piezoelectric material. The piezoelectric vibration element may be used.

  Further, in the above-described embodiment, the case where the tuning fork type bending crystal vibrating element is used as the piezoelectric vibrating element has been described. However, a piezoelectric vibrating element used as an AT-cut quartz vibrating element may be used.

  In the above-described embodiment, the case where the element mounting member 210 constituting the piezoelectric device 300 has a length in the long side direction of 2.0 mm and a length in the short side direction of 0.8 mm has been described. The present invention can be applied even when the length in the long side direction is 2.0 mm or less and the length in the short side direction is 1.6 mm or less.

  In the present embodiment, the sheet substrate provided with a plurality of element mounting members has been described. However, after the individual element mounting members are accommodated in a conveying jig or the like, grooves may be formed using a laser. I do not care.

210: Element mounting member 210a: Substrate part 210b: First frame part 210b: Second frame part 211: Piezoelectric vibration element mounting pad 212: Sealing conductor pattern 214 ... Groove part 100 ... Piezoelectric vibration element (Tuning fork type bending crystal vibration element)
DESCRIPTION OF SYMBOLS 110 ... Crystal base plate 230 ... Lid member 231 ... Sealing member 200 ... Sheet substrate for piezoelectric device 300 ... Piezoelectric device (piezoelectric vibrator)
G: Electrode terminal for external connection K1: Recessed space DS: Conductive adhesive

Claims (3)

A substrate portion and an element mounting member in which a first frame portion and a second frame portion are provided on one main surface of the substrate portion to form a recessed space;
A pair of piezoelectric vibration element mounting pads provided on the main surface of the first frame portion exposed in the recess space;
A piezoelectric vibration element mounted on the two pairs of piezoelectric vibration element mounting pads;
A lid for hermetically sealing the recessed space;
A groove portion provided between the piezoelectric vibration element mounting pads on the main surface of the first frame portion,
A piezoelectric device, wherein a relationship between a length W1 in the depth direction of the groove and a thickness W2 of the first frame portion is 0.4 ≦ W1 / W2 ≦ 0.9.   The relationship between the length L1 in the short side direction of the groove and the length L3 between the two pairs of piezoelectric vibration element mounting pads is 0.3 ≦ L1 / L3 ≦ 0.8. Item 1. A piezoelectric device according to Item 1. A first frame portion and a second frame portion are provided on one main surface of the substrate portion and the substrate portion to form a recessed space, and the first frame portion is exposed in the recessed space. A groove portion that forms a groove portion by laser processing or sandblasting between the piezoelectric vibration element mounting pads on the main surface of the first frame portion of the element mounting member provided with two pairs of piezoelectric vibration element mounting pads on the main surface Forming process;
A piezoelectric vibration element mounting step of mounting the piezoelectric vibration element on a piezoelectric vibration element mounting pad provided in the recessed space of the element mounting member;
A lid member joining step of joining a lid member to the element mounting member so as to hermetically seal the piezoelectric vibration element.

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