JP2009081670A - Piezoelectric vibration device and manufacturing method thereof - Google Patents

Abstract

Disclosed is a variation in bonding strength when a piezoelectric vibrating piece is bonded to a base.
In a crystal resonator, a support material that holds a crystal vibrating piece, a base that holds the crystal vibrating piece through the support material, and a crystal vibrating piece that is held by the base are separated. A lid 4 joined to the base 3 is provided for hermetically sealing. The support material 5 is bump-bonded to the base 3 with base bumps 71, and the crystal vibrating piece 2 is bump-bonded to the support material 5 with crystal vibrating piece bumps 72. In this quartz crystal resonator 1, at least one of the bonding parts 51 of the support material 5 to the crystal vibrating piece 2 or the bonding parts 261 and 262 of the crystal vibrating piece 2 to the support material 5 has an uneven shape.
[Selection] Figure 3

Description

  The present invention relates to a piezoelectric vibration device and a manufacturing method thereof.

Currently, examples of the piezoelectric vibration device include a crystal oscillator and a crystal resonator. In this type of piezoelectric vibration device, the casing is formed of a rectangular parallelepiped package. This package is composed of a base and a lid. Inside the package, a piezoelectric vibrating piece is bump-bonded to the base via a conductive bump by the FCB method, and the piezoelectric vibrating piece is held in one piece. And the piezoelectric vibration piece inside a package is airtightly sealed by joining a base and a lid | cover (for example, refer patent document 1 mentioned below).
JP 2001-85966 A

  By the way, in Patent Document 1, as described above, when the piezoelectric vibrating piece is held on the base, the piezoelectric vibrating piece is bump-bonded to the base by ultrasonic bonding using the FCB method via the conductive bump.

  Regarding bump bonding by this FCB method, there is a concern about variation in bonding strength of the piezoelectric vibrating piece to the base.

  Therefore, in order to suppress variations in bonding strength, for example, various bonding conditions are changed when the piezoelectric vibrating piece is bonded to the base (for example, changing the bump material or changing the pressure bonding strength of the FCB method). When the bump bonding of the piezoelectric vibrating piece by FCB method is performed, the bonding strength itself of the piezoelectric vibrating piece to the base can be enhanced.

  However, there is little effect of suppressing variation in bonding strength due to changing the bonding condition of the piezoelectric vibrating piece to the base. Specifically, according to the prior art, variation in bonding strength occurs within a range of ± 30% of the desired bonding strength, and there is a range of variation in strength after bonding. A piezoelectric vibration device having the above cannot be manufactured stably.

  Accordingly, in order to solve the above-described problems, an object of the present invention is to provide a piezoelectric vibration device that suppresses variation in bonding strength when bonding a piezoelectric vibrating piece to a base, and a method for manufacturing the same.

  In order to achieve the above object, a piezoelectric vibrating device according to the present invention includes a support material that holds a piezoelectric vibrating piece, a base that holds the piezoelectric vibrating piece via the support material, and the piezoelectric vibration that is held on the base. In order to hermetically seal the piece, a lid joined to the base is provided, and the support material is bump-bonded to the base by a base bump, and the piezoelectric vibrating piece is bumped to the support material by a piezoelectric vibrating piece bump In the bonded piezoelectric vibration device, at least one of the bonded portion of the support material to the piezoelectric vibrating piece or the bonded portion of the piezoelectric vibrating piece to the support material has an uneven shape. .

  According to the present invention, it is possible to suppress variation in bonding strength when bonding the piezoelectric vibrating piece to the base. This is because, according to the present invention, at least one of the bonding portion of the support material to the piezoelectric vibrating piece or the bonding portion of the piezoelectric vibrating piece to the support material has an uneven shape. And the joining position can be determined, and as a result, the joining strength can be made constant. Therefore, it is possible to suppress variations in bonding strength when bonding the piezoelectric vibrating piece to the base.

  In the above configuration, the piezoelectric vibrating piece bump includes a first piezoelectric vibrating piece bump and a second piezoelectric vibrating piece bump, and the first piezoelectric vibrating piece bump is joined to the piezoelectric vibrating piece. And the second piezoelectric vibrating piece bump is formed at the bonding portion of the support material, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are ultrasonically bonded. The piezoelectric vibrating piece may be bump-bonded to the support material.

  In this case, the first piezoelectric vibrating piece bump is formed at the bonding portion of the piezoelectric vibrating piece, the second piezoelectric vibrating piece bump is formed at the bonding portion of the support material, and the first piezoelectric vibration piece is formed. Since the bump for one piece and the bump for the second piezoelectric vibrating piece are ultrasonically bonded and the piezoelectric vibrating piece is bump-bonded to the support material, the bump for the first piezoelectric vibrating piece and the second piezoelectric piece are bonded. The vibrating piece bumps are bump bonded to the piezoelectric vibrating piece and the support material in advance. Therefore, it is possible to stably perform bump bonding between the first piezoelectric vibrating piece bump and the piezoelectric vibrating piece, and it is possible to stably perform bump bonding between the second piezoelectric vibrating piece bump and the support material. Can be performed. Under this condition, the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are bonded to each other, so that the bump is bonded to the support material or the piezoelectric vibrating piece by ultrasonic bonding. Compared to joining, according to the present invention, since the piezoelectric vibrating piece is joined to the support material by joining bumps, the material of the joining target member can be a material suitable for joining, As a result, it becomes possible to stably bond the piezoelectric vibrating piece to the support material via the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump.

  In the above configuration, at least one of the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump is a plated bump, and the piezoelectric vibrating piece is disposed on the support material. May be diffusion bonded.

  In this case, it is possible to increase the bonding strength of the piezoelectric vibrating piece to the support material. In addition, as compared with a case where diffusion bonding is not used for bonding the piezoelectric vibrating piece to the support material, the piezoelectric vibrating piece is bonded to the support material at a low temperature and low pressure via the piezoelectric vibrating piece bump. Therefore, the piezoelectric vibrating reed bumps can be easily diffused (slid easily) by low temperature and low pressure, and the piezoelectric vibrating reed can be joined to the support material.

  In the above configuration, the bonding portion of the support material with the piezoelectric vibrating piece has an uneven shape, the bonding portion of the piezoelectric vibrating piece with the support material has an uneven shape, and the piezoelectric vibration of the support material A concave portion and a convex shape are respectively formed at a joint portion with the piece and a joint portion with the support member of the piezoelectric vibrating piece, and the first piezoelectric vibrating piece bump and the second piezoelectric vibration are formed. A single bump is formed in the concave shape and the convex shape, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump formed in the concave shape and the convex shape are super The piezoelectric vibrating piece may be bump-bonded to the pressure support material by sonic bonding, which is preferable for increasing the bonding strength.

  In the above configuration, the bonding portion of the support material with the piezoelectric vibrating piece has an uneven shape, the bonding portion of the piezoelectric vibrating piece with the support material has an uneven shape, and the piezoelectric vibration of the support material A concave shape is formed in each of a bonding portion with the piece and a bonding portion of the piezoelectric vibrating piece with the support material, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump Are formed in each of the concave shapes, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump formed in the concave shape are ultrasonically bonded to the pressure support material to form the piezoelectric vibration. The pieces may be bump bonded.

  In this case, it is possible to narrow a gap between the piezoelectric vibrating piece and the support material when the piezoelectric vibrating piece is bonded to the support material, and as a result, it is suitable for reducing the height of the piezoelectric vibrating device. .

  In order to achieve the above object, a method of manufacturing a piezoelectric vibrating device according to the present invention includes a support material that holds a piezoelectric vibrating piece, a base that holds the piezoelectric vibrating piece via the support material, and a base that holds the piezoelectric vibrating piece. In order to hermetically seal the piezoelectric vibrating piece, a lid that is bonded to a base is provided, and the support material is bump-bonded to the base with a base bump, and the piezoelectric vibrating piece is bonded to the support material with a piezoelectric vibrating piece bump. In the method of manufacturing a piezoelectric vibration device for bump bonding, at least one of the bonding portion of the support material to the piezoelectric vibrating piece or the bonding portion of the piezoelectric vibrating piece to the support material has an uneven shape, and the FCB By using this method, the piezoelectric vibration piece bonding portion is ultrasonically bonded to the support material bonding portion using the piezoelectric vibration piece bump. The features.

  According to the present invention, it is possible to suppress variation in bonding strength when bonding the piezoelectric vibrating piece to the base. This is because, according to the present invention, at least one of the bonding portion of the support material to the piezoelectric vibrating piece or the bonding portion of the piezoelectric vibrating piece to the support material has an uneven shape. And the joining position can be determined, and as a result, the joining strength can be made constant. Therefore, it is possible to suppress variations in bonding strength when bonding the piezoelectric vibrating piece to the base.

  In the method, the piezoelectric vibrating piece bump includes a first piezoelectric vibrating piece bump and a second piezoelectric vibrating piece bump, and the first piezoelectric vibrating piece bump is bonded to the piezoelectric vibrating piece. The second piezoelectric vibrating piece bump is formed at the bonding portion of the support material, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are ultrasonically bonded. The piezoelectric vibrating piece may be bump-bonded to the support material.

  In this case, the first piezoelectric vibrating piece bump is formed at the bonding portion of the piezoelectric vibrating piece, the second piezoelectric vibrating piece bump is formed at the bonding portion of the support material, and the first piezoelectric vibration piece is formed. Since the bump for one piece and the bump for the second piezoelectric vibrating piece are ultrasonically bonded and the piezoelectric vibrating piece is bump bonded to the support material, the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece are bonded. The single bumps are bump bonded to the piezoelectric vibrating piece and the support material in advance. Therefore, it is possible to stably perform bump bonding between the first piezoelectric vibrating piece bump and the piezoelectric vibrating piece, and it is possible to stably perform bump bonding between the second piezoelectric vibrating piece bump and the support material. Can be performed. Under this condition, the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are bonded to each other, so that the bump is bonded to the support material or the piezoelectric vibrating piece by ultrasonic bonding. Compared to joining, according to the present invention, since the piezoelectric vibrating piece is joined to the support material by joining bumps, the material of the joining target member can be a material suitable for joining, As a result, it becomes possible to stably bond the piezoelectric vibrating piece to the support material via the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump.

  In the method, at least one of the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump is a plated bump, the piezoelectric vibrating piece is used as the support material, and the piezoelectric vibrating piece bump is used. May be diffusion bonded.

  In this case, it is possible to increase the bonding strength of the piezoelectric vibrating piece to the support material. In addition, as compared with a case where diffusion bonding is not used for bonding the piezoelectric vibrating piece to the support material, the piezoelectric vibrating piece is bonded to the support material at a low temperature and low pressure via the piezoelectric vibrating piece bump. Therefore, the piezoelectric vibrating reed bumps can be easily diffused (slid easily) by low temperature and low pressure, and the piezoelectric vibrating reed can be joined to the support material.

  In the method, a joint portion of the support material with the piezoelectric vibrating piece has an uneven shape, a joint portion of the piezoelectric vibrating piece with the support material has an uneven shape, and the piezoelectric vibration of the support material The first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece are formed in a concave shape and a convex shape, respectively, at a bonding portion with the piece and a bonding portion of the piezoelectric vibrating piece with the support material. And forming the concave bump and the convex bump, and ultrasonically bonding the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump formed in the concave shape and the convex shape. Then, the piezoelectric vibrating piece may be bump-bonded to the pressure support material. In this case, it is preferable to increase the bonding strength.

  In the method, a joint portion of the support material with the piezoelectric vibrating piece has an uneven shape, a joint portion of the piezoelectric vibrating piece with the support material has an uneven shape, and the piezoelectric vibration of the support material Forming a concave shape in each of a bonding portion with the piece and a bonding portion of the piezoelectric vibrating piece with the support material, and the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump The first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump formed in the concave shape are ultrasonically bonded to the pressure support material, and the piezoelectric vibrating piece is attached to the pressure support material. Bump bonding may be used.

  In this case, it is possible to narrow a gap between the piezoelectric vibrating piece and the support material when the piezoelectric vibrating piece is bonded to the support material, and as a result, it is suitable for reducing the height of the piezoelectric vibrating device. .

  According to the present invention, it is possible to suppress variation in bonding strength when bonding a piezoelectric vibrating piece to a base.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each example shown below, a case where the present invention is applied to a crystal resonator as a piezoelectric vibration device is shown.

  In the crystal resonator 1 according to the present embodiment, as shown in FIGS. 1 and 2, a crystal vibrating piece 2 (piezoelectric vibrating piece referred to in the present invention), a base 3 for holding the crystal vibrating piece 2, and a base 3 A lid 4 for hermetically sealing the quartz crystal vibrating piece 2 held on the support and a support member 5 for reducing external stress on the quartz crystal vibrating piece 2 are provided.

  In this crystal resonator 1, a package 6 is constituted by a base 3 and a lid 4, and the base 3 and the lid 4 are joined to form an internal space of the package 6. On the base 3 in the internal space of the package 6. In addition, the crystal vibrating piece 2 is held via the support material 5 and the internal space of the package 6 is hermetically sealed. At this time, as shown in FIGS. 1 and 2, the base 3, the crystal vibrating piece 2, and the support material 5 are each made of FCB method using bumps (base bump 71 and crystal vibrating piece bump 72) made of a metal material. Is electromechanically ultrasonically bonded.

  The crystal vibrating piece bump 72 referred to here is composed of a first crystal vibrating piece bump 73 and a second crystal vibrating piece bump 74. The first crystal vibrating piece bump 73 is formed at the bonding portions 261 and 262 (see below) of the crystal vibrating piece 2 before the crystal vibrating piece 2 is bonded to the support material 5. 74 is formed at a bonding portion 51 (see below) of the support material 5 before the crystal vibrating piece 2 is bonded to the support material 5, and the first crystal vibrating piece bump 73 and the second crystal vibrating piece bump 74 are formed. Are subjected to ultrasonic bonding (diffusion bonding), and the crystal vibrating piece 2 is bump bonded to the support material 5. The base bump 71 includes a first base bump 75 and a second base bump 76. The first base bump 75 is formed on the joint portion 34 (see below) of the base 3 before the support material 5 is joined to the base 3, and the second base bump 76 is formed on the base 3 of the support material 5. The first base bump 75 and the second base bump 76 are ultrasonically bonded (diffusion bonded) to the base 3 to form the support material. 5 is bump-bonded.

  Next, each configuration of the crystal resonator 1 will be described with reference to FIGS. FIG. 3 is a diagram showing each component of the crystal unit 1 before the crystal unit 1 is manufactured.

  As shown in FIGS. 1 to 3, the base 3 is formed in a box-like body including a bottom portion 31 and a wall portion 32 extending upward from the bottom portion 31. The base 3 is formed by laminating a rectangular parallelepiped of a ceramic material on a single plate having a rectangular shape in a plan view made of a ceramic material, and integrally firing in a concave shape. In addition, the dimension of the base 3 according to the present embodiment in a plan view is set to 2.5 mm × 3.2 mm or less.

  The wall portion 32 is formed along the outer periphery of the surface of the bottom portion 31. The upper surface of the wall portion 32 is a bonding area with the lid 4. The bonding area has a metallized layer 33 (for example, nickel and gold plated on a tungsten metallized layer in this order) for bonding with the lid 4. Is provided.

  In addition, the base 31 is provided with a joint portion 34 between the support member 5 and the support member 5 to be electromechanically joined to the excitation electrodes 231 and 232 of the crystal vibrating piece 2. A plurality of convex shapes projecting with respect to the bottom 31 are formed in the joint portion 34. A plurality of electrode pads (not shown) that are electromechanically bonded to the excitation electrodes 231 and 232 of the crystal vibrating piece 2 are formed at the bonding portion 34. These electrode pads are respectively electromechanically joined to terminal electrodes (not shown) formed on the outer peripheral back surface of the base 3. These terminal electrodes are connected to external parts and external devices. These terminal electrodes and electrode pads are formed by printing integrally with the base 3 after printing a metallized material such as tungsten or molybdenum. Some of these terminal electrodes and electrode pads are formed by forming nickel plating on the metallized upper portion and forming gold plating on the upper portion thereof. Further, before joining the support material 5 to the base 3, as shown in FIG. 3, the first base bump 75 made of gold plating is formed on the projection surface (electrode pad surface) of the convex portion. In addition, an electrolytic plating method or an electroless plating method is used as the plating method here. Further, in the base 3 of the present embodiment, a plurality of convex shapes are formed, but the present invention is not limited to this, and a plurality of concave shapes may be formed, and a plurality of convex shapes and concave shapes may be formed. It may be formed.

  The lid 4 is made of, for example, a metal material, and is formed into a single plate having a rectangular shape in plan view as shown in FIG. The lid 4 has a brazing material 41 formed on the lower surface, and is joined to the base 3 by a technique such as beam welding, so that the package 6 of the crystal unit 1 is configured by the lid 4 and the base 3. In addition, the dimension of the plan view of the lid 4 according to the present embodiment is set to 2.5 mm × 3.2 mm or less.

  Moreover, the lid | cover 4 is formed from the metal material from which the thermal expansion coefficient differs, for example of 4 layers. Specifically, a silver brazing layer, a copper layer, a kovar layer, and a nickel layer, which are brazing materials, are laminated in this order from the lower surface of the lid 4 serving as a connection surface with the base 3. Since the lower surface side of the lid is a silver brazing layer and a copper layer, thermal bonding with the base 3 made of ceramic is easier than other layers. Further, since the Kovar layer is laminated on the silver brazing layer and the copper layer, it is possible to make the thermal deformation of the base 3 and the lid 4 equal by making the thermal expansion coefficient of the base 3 made of ceramic substantially the same. It becomes possible. In addition, since the nickel layer is formed on the uppermost surface, it is easy to perform seam welding between the base 3 and the lid 4. Note that the Kovar layer is designed to be as thick as possible in order to achieve the same level of thermal deformation.

  As shown in FIGS. 1 to 3, the quartz crystal vibrating piece 2 includes an AT-cut quartz crystal substrate 21 and is formed into a rectangular parallelepiped having a rectangular shape in plan view, and the outer periphery of the substrate 21 has a rectangular parallelepiped shape. In addition, the main surface dimension of the crystal vibrating piece 2 according to the present embodiment is set to 1.4 mm × 2.0 mm or less, and the height dimension of the crystal vibrating piece 2 is set to 0.1 mm or less.

  Concave portions 201 are formed on both main surfaces 221 and 222 of the substrate 21 of the quartz crystal vibrating piece 2 in order to cope with the high frequency of the quartz crystal vibrating piece 2, and excitation electrodes 231 and 232 are respectively formed inside the concave portions 201. The extraction electrodes 241 and 242 led out from the excitation electrodes 231 and 232 are formed to electromechanically join these excitation electrodes 231 and 232 with external electrodes (in this embodiment, the electrode pads of the base 3). Yes. In addition, the crystal vibrating piece 2 is bonded to the support material 5 and the crystal vibrating piece bumps 72 at a plurality of portions 261 and 262 (bonded portions 261 and 262) of the substrate 21. Note that a plurality of convex shapes projecting from the main surface 221 are respectively formed in the bonding portions 261 and 262 of the substrate 21 in this embodiment, and these bonding portions 261 and 262 are one end portions in the longitudinal direction of the substrate 21. 27 and provided at both ends in the lateral direction. In addition, as shown in FIG. 2, lead electrodes 241 and 242 are drawn out from these joint portions 261 and 262, respectively. Further, before the crystal vibrating piece 2 is bonded to the support member 5, as shown in FIG. 3, the first crystal vibrating piece bump 73 made of gold plating is formed on the projection surfaces of these joint portions 261 and 262. Yes. The excitation electrodes 231 and 232 are electromechanically joined to the electrode pad of the base 3 by the crystal vibrating piece bump 72 and the base bump 71 via the support material 5 from the extraction electrodes 241 and 242. The excitation electrodes 231 and 232 and the extraction electrodes 241 and 242 are formed by photolithography. For example, from the substrate 21 side, chromium, gold (Cr—Au), or chromium, gold, chromium (Cr— Au—Cr), or chromium, gold, nickel (Cr—Au—Ni), or chromium, silver, chromium (Cr—Ag—Cr), or chromium, nickel (Cr—Ni). Alternatively, nickel and chromium (Ni—Cr) are laminated in this order. In the crystal vibrating piece 2 of the present embodiment, a plurality of convex shapes are formed. However, the present invention is not limited to this, and a plurality of concave shapes may be formed. A shape may be formed.

  As shown in FIG. 2, the support material 5 is a Z plate made of a crystal piece that is a brittle material. As shown in FIG. 1, the outer shape of the support material 5 is set to be substantially the same as the outer shape of the crystal vibrating piece 2 in plan view, and the support material 5 is formed into a rectangular parallelepiped having a rectangular shape in plan view. ing. In addition, the dimension in plan view of the support material 5 according to the present embodiment is set to 1.4 mm × 2.0 mm or less, and the height dimension of the support material 5 is set to 0.1 mm or less.

  As shown in FIGS. 1 and 2, the support member 5 has a crystal vibrating piece bonding portion 51 (hereinafter referred to as bonding) for bonding to the crystal vibrating piece 2 on one main surface (the front side in FIG. 1). A base joint portion 52 (hereinafter referred to as a joint portion 52) for joining to the base 3 is provided on the other main surface (the back side in FIG. 1). A plurality of concave shapes are formed in the joint part 51 and the joint part 52 of the support material, respectively. A lead electrode (not shown) is routed between the joint part 51 and the joint part 52. In addition, the junction part 51 here is the one end part of the longitudinal direction of one main surface of the support material 5 as shown in FIG. 3, and is set to the both ends of a transversal direction. Moreover, the junction part 52 here is the both ends of the longitudinal direction which the other main surface of the support material 5 opposes, and is set to the both sides of a transversal direction. Further, a second crystal vibrating piece bump 74 and a second base bump 76 made of gold bumps are respectively formed on the inner bottom surfaces of the concave portions of the joint portion 51 and the joint portion 52. In addition, in the support material 5 of a present Example, although several concave shape is formed, it is not limited to this, A several convex shape may be formed, and also a plurality of convex shape and concave shape May be formed.

  As shown in FIGS. 1 to 3, the base 3 and the support material 5 are ultrasonically bonded at four points at four bonding sites 52 by the base bumps 71, and the crystal vibrating piece 2 and the support material 5 are crystal-vibrated. The two bumps 72 are ultrasonically bonded at two points at the two bonding sites 51 and are electromechanically bonded. By these bondings, the excitation electrodes 231 and 232 of the crystal vibrating piece 2 are respectively connected to the electrodes of the base 3 via the lead electrodes 241 and 242, the crystal vibrating piece bump 72, the support electrode of the support material 5, and the base bump 71. Electromechanically bonded to the pad. Further, the base connection bump 71 and the crystal vibrating piece connection bump 72 are formed at the same position in plan view as shown in FIG. Here, the same position in plan view includes the position shown in FIG. 1 where the connection bumps 71 for base and the connection bumps 72 for crystal resonator element overlap in plan view, but this is a preferred example. The position is not limited to this, and includes a positional relationship in which the base connection bump 71 and the crystal vibration piece connection bump 72 partially overlap in plan view.

  By the way, when the support material 5 is joined to the base 3 and the crystal vibrating piece 2 is thermally joined to the support material 5, external deformation or distortion occurs in each member. Due to this external deformation or distortion, a stress such as a thermal stress is generated in the package 6, and this stress is applied to the crystal vibrating piece 2 through the support material 5.

  However, according to the above-described crystal resonator 1 according to the present embodiment, the crystal vibrating piece 2 is held on the base 3 via the support material 5 made of a brittle material. Even when the package 6 is stressed when being held or when the lid 4 is bonded to the base 3, it is possible to suppress the stress from being applied to the crystal vibrating piece 2. In particular, the operational effects of the crystal resonator 1 according to the present embodiment are conspicuous as compared with a crystal resonator in which a crystal resonator element is directly joined to a base via a conductive bump as in the prior art.

  Specifically, since the crystal vibrating piece 2 is ultrasonically bonded onto the base 3 via the support material 5 by the FCB method, the lid 4 is bonded to the base 3 when holding the crystal vibrating piece 2 on the base 3. Even when a stress is applied to the package 6, the stress can be suppressed from being applied to the crystal vibrating piece 2. Further, according to the present embodiment, it is suitable for reducing the size of the package 6, and in particular, the operation and effect of the present embodiment is based on the background art (for example, the conventional technique described in Patent Document 1). In particular, it appears significantly in comparison with a piezoelectric vibrating device in which a piezoelectric vibrating piece is bonded directly via a conductive bump.

  Next, a method for manufacturing the crystal unit 1 will be described with reference to FIGS.

  First, as shown in FIG. 3, first base bumps 75 made of gold plating are formed on the surface of the projection of the joint portion 34 of the base 3 with the support material 5. In addition, the first crystal vibrating piece bump 73 made of gold plating is formed on the surface of the projection of the joint portions 261 and 262 of the crystal vibrating piece 2 with the support material 5. Further, a second base bump 76 made of a gold bump is formed on the bottom surface of the concave portion of the joint portion 52 of the support material 5.

  Then, the second base bump 76 formed on the support material 5 is brought into contact with the first base bump 75 formed on the base 3, and the first base bump 75 and the second base bump 76 are connected to each other. Then, the bonding part 52 of the support material 5 is electromechanically bump-bonded to the bonding part 34 of the base 3 by diffusion bonding by ultrasonic bonding by the FCB method.

  After the support material 5 is bonded to the base 3, a second crystal vibrating piece bump 74 made of a gold bump is formed on the bottom surface of the concave portion of the bonding portion 51 of the support material 5.

  After the second crystal vibration piece bump 74 is formed on the support material 5, the second crystal vibration piece bump formed on the support material 5 is formed on the first crystal vibration piece bump 73 formed on the crystal vibration piece 2. 74 is touched. Then, the first crystal vibrating piece bump 73 and the second crystal vibrating piece bump 74 are diffusion-bonded by ultrasonic bonding by the FCB method, so that the crystal vibrating piece is bonded to the bonding portion 51 of the support material 5. Two joint portions 261 and 262 are bump-bonded electromechanically.

After the crystal vibrating piece 2 is joined to the base 3 through the support material 5 by the above-described process,
The metallized layer 33 of the base 3 is brought into contact with the brazing material 41 formed on the lower surface of the lid 4, and the metallized layer 33 and the brazing material 41 are joined together by a technique such as seam or beam welding to hermetically seal the internal space. The crystal resonator 1 is manufactured.

  The dimensions of the crystal unit 1 manufactured in this example are as follows. The external shape of the crystal unit 1 is set to 2.5 mm × 3.2 mm × 0.75 mm or less. The internal space of the crystal unit 1 is set to 1.7 mm × 2.6 mm × 0.35 mm or less. In addition, the height of the base bump 71 in the internal space is set to 0.02 mm or less, and the height of the crystal vibrating piece bump 72 is set to 0.02 mm or less.

  As described above, according to the present embodiment, the joining portion 51 of the support material 5 with the crystal vibrating piece 2 and the joining portions 261 and 262 of the crystal vibrating piece 2 with the support material 5 are formed in an uneven shape. The strength can be increased and the joining position can be determined. As a result, the joining strength can be made constant. Therefore, according to the present embodiment, it is possible to suppress variation in bonding strength when the crystal vibrating piece 2 is bonded to the base 3. The bump bonding of the base 3 and the support material 5 via the base bump 71 has the same effect, but the bump of the crystal vibrating piece 2 and the support material 5 via the crystal vibrating piece bump 72 is also provided. The effect of joining is more prominent. However, it is more preferable to use both the bump bonding through the base bump 71 between the base 3 and the support material 5 and the bump bonding through the crystal vibration piece bump 72 between the crystal vibrating piece 2 and the support material 5 together. Needless to say. In particular, in this case, it is possible to further stabilize the bonding of the crystal vibrating piece 2 mounted on the support material 5 by stabilizing the bonding of the support material 5 to the base 3 serving as a support base of the crystal vibrating piece 2. .

  Further, according to the present embodiment, the first crystal vibrating piece bump 73 is formed in the joint portions 261 and 262 of the crystal vibrating piece 2, and the second crystal vibrating piece bump 74 is formed in the joint portion 51 of the support material 5. The first crystal vibration piece bump 73 and the second crystal vibration piece bump 74 are ultrasonically bonded and the crystal vibration piece 2 is bump-bonded to the support material 5. The piece bump 73 and the second crystal vibration piece bump 74 are bump-bonded to the crystal vibration piece 2 and the support material 5 in advance, respectively. Therefore, the bump bonding between the first crystal vibrating piece bump 73 and the crystal vibrating piece 2 can be performed stably, and the bump bonding between the second crystal vibrating piece bump 74 and the support material 5 can be performed stably. Can be done. Under this condition, the first crystal vibrating piece bump 73 and the second crystal vibrating piece bump 74 are bump-bonded, so that the bump is bonded to the support material 5 or the crystal vibrating piece 2 by ultrasonic bonding. Compared to joining, according to the present embodiment, the crystal vibrating piece 2 is joined to the support material 5 by joining the bumps, so that the material of the joining target member can be a material suitable for joining, As a result, it is possible to stably bond the crystal vibrating piece 2 to the support material 5 via the first crystal vibrating piece bump 73 and the second crystal vibrating piece bump 74.

  Further, according to the present embodiment, the crystal vibrating piece 2 is diffusion-bonded to the support material 5 by the crystal vibrating piece bumps 72, so that the bonding strength of the crystal vibrating piece 2 to the support material 5 can be increased. Further, as compared with the case where the diffusion bonding is not used for bonding the crystal vibrating piece 2 to the support material 5, the crystal vibrating piece 2 is bonded to the support material 5 via the crystal vibrating piece bumps 72 at a low temperature and a low pressure. . Therefore, the crystal vibrating piece bump 72 can be easily diffused (slidable) by low temperature and low pressure, and the crystal vibrating piece 2 can be bonded to the support material 5.

  Further, since the support material 5 is made of a brittle material, the expansion coefficient of the support material 5 approximates the expansion coefficient of the quartz crystal vibrating piece 2. Therefore, there is no deterioration of the characteristics of the crystal vibrating piece 2 due to the support material 5 provided between the base 3 and the crystal vibrating piece 2, and external stress can be buffered.

  Further, as shown in FIG. 1, the outer shape of the support material 5 is set to be substantially the same as the outer shape of the quartz crystal vibrating piece 2, so that the size reduction of the crystal unit 1 is prevented by the installation of the support material 5. However, the crystal unit 1 can be downsized.

  Further, the crystal vibrating piece 2 is a crystal piece, and the support material 5 is a Z plate made of a crystal piece and is not easily affected by anisotropy. The shape of the support material 5 can be easily formed into an arbitrary shape without being affected by the directivity. In addition, when the AT cut plate similar to the crystal vibrating piece is used for the support material 5, it is more susceptible to etching when forming the support material 5 than the Z plate, and is perpendicular to the preset axis. Even if it is a case where it wants to etch, since it etches in the diagonal direction, it is difficult to shape | mold the shape of the support material 5 in arbitrary shapes. Therefore, it is preferable to use a Z plate for the support material 5. Further, since the support material 5 is a material that is not easily affected by anisotropy, it is not affected by the vibration of the crystal vibrating piece 2, and the characteristics of the crystal vibrating piece 2 are deteriorated by the installation of the support material 5. Can be prevented. Further, since the crystal vibrating piece 2 and the support material 5 are the same crystal piece, the expansion coefficient is the same, and buffering external stress by providing the support material 5 between the base 3 and the crystal vibrating piece 2. preferable.

  In the present embodiment, a quartz piece is applied as the support material 5, but the present invention is not limited to this, and other forms may be used as long as it is a brittle material. It may be made of no glass material.

  Further, in this embodiment, as shown in FIG. 1, a lid 4 formed in a rectangular parallelepiped on a rectangular plate in plan view and a base 3 formed in a concave shape are used, but the present invention is not limited to this. The shape of the base and the lid may be arbitrarily set as long as the quartz crystal vibrating piece 2 can be hermetically sealed by the base 3 and the lid 4. For example, you may use the base shape | molded by the rectangular parallelepiped of the single plate on a planar view rectangle, and the cover shape | molded by the concave shape.

  In this embodiment, one excitation electrode 231 and 232 is formed on each of the main surfaces 221 and 222 of the crystal vibrating piece 2, but the present invention is not limited to this, and both the main electrodes 221 and 222 are used according to the intended use. The number of excitation electrodes formed on each of the surfaces 221 and 222 may be arbitrarily set. For example, two excitation electrodes may be formed on both main surfaces, or a filter element configuration in which one excitation electrode is formed on one main surface and two excitation electrodes are formed on the other main surface. Good.

  Further, the extraction electrodes 241 and 242 of the crystal vibrating piece 2 are not limited to the above-described embodiments, and may be further formed by plating. In addition, an electrolytic plating method or an electroless plating method is used as the plating method here.

  Further, in the present embodiment, a member that emits ultrasonic waves of the FCB apparatus is directly brought into contact with the facing position 28 facing the bonding portion of the crystal vibrating piece 2 to the support material 5 by the FCB method, so that the crystal vibrating piece 2 is supported on the support material 5. The crystal vibration piece bumps 72 are joined to each other. By the way, as shown in the present embodiment, when the extraction electrodes 241 and 242 are formed at the opposed positions 28 of the quartz crystal vibrating piece 2 in direct contact with the ultrasonic wave generating member of the FCB device, the ultrasonic wave of the FCB device is transmitted. The extraction electrodes 241 and 242 are attached to the emitting member, that is, the extraction electrodes 241 and 242 are peeled off from the crystal vibrating piece 2 and are fixed to the member that emits ultrasonic waves of the FCB apparatus. Therefore, when joining the other quartz crystal vibrating piece 2 to the support material 5 in a state where the extraction electrodes 241 and 242 are fixed to the member that emits ultrasonic waves of the FCB apparatus, the joining strength by the FCB method is weakened. Therefore, when the extraction electrodes 241 and 242 are fixed to the member that emits ultrasonic waves of the FCB apparatus, it is necessary to remove the fixed extraction electrodes 241 and 242. In order to solve this problem, the substrate 21 may be exposed at the facing position 28 of the crystal vibrating piece 2. In this case, even when the member that emits ultrasonic waves of the FCB apparatus is brought into direct contact with the facing position 28 by the FCB method, the substrate 21 at the facing position 28 does not adhere to the member that emits ultrasonic waves of the FCB apparatus. . Further, although it is mentioned as a preferred example that the substrate 21 at the position facing the crystal vibrating piece 2 is exposed, the present invention is not limited to this, and an insulating material is formed at the position 28 facing the crystal vibrating piece 2. May be. As used herein, the insulating material may be an insulating material as a whole or may be a material in which only the surface of the material is insulated, an insulating material such as magnesium fluoride, silicon oxide, silicon dioxide, or chromium oxide. A metal oxide compound such as For example, an insulating material obtained by oxidizing the surface of a material made of chromium may be used. Furthermore, the configuration for solving the above-described problem is not only that an insulating material is formed at the facing position 28 of the crystal vibrating piece 2 but also that the lead electrode is made of a material made of a single layer of chromium at the facing position 28 of the crystal vibrating piece 2. May be formed. The reason for mentioning the single layer of chromium here is that chromium is harder than gold and has high bonding strength with the substrate 21 of the quartz crystal resonator element 2, so that it is compared with the material made of gold as described above. This is related to the fact that it does not adhere to the ultrasonic wave generating member of the FCB device. In addition to the chromium single layer, for example, at least the opposing position 28 of the extraction electrodes 241 and 242 among the excitation electrodes 231 and 232 and the extraction electrodes 241 and 242 is formed by sequentially stacking chromium and nickel (or vice versa). It may be an extracted electrode. Moreover, the structure which laminated | stacks chromium and gold | metal | money in order and remove | eliminated only the surface gold | metal | money after that, and made it the chromium single layer may be sufficient. That is, the combination may be arbitrarily set as long as chromium is arranged on the surface.

  According to the above-described example, since the lead electrode made of an insulating material or a single layer of chromium is formed at the facing position 28 of the crystal vibrating piece 2, the ultrasonic wave of the FCB device is emitted to the facing position 28 of the crystal vibrating piece 2 by the FCB method. Even when the members are brought into direct contact, it is possible to prevent the insulating material or the material made of a single layer of chromium formed at the facing position 28 of the quartz crystal vibrating piece 2 from adhering to the ultrasonic wave generating member of the FCB apparatus. it can.

  In this embodiment, the support material 5 formed in a rectangular parallelepiped rectangular shape as shown in FIGS. 1 and 2 is used, but the shape of the support material is limited to this. Instead, a concave portion may be provided to prevent thermal stress from being transmitted to the quartz crystal vibrating piece 2, and the quartz crystal vibrating piece 2 is bonded to the support material 5 so that the quartz crystal vibrating piece 2 is attached to the support material 5. You may provide the pillow part for crystal vibrating pieces which suppresses bending. In particular, by providing the crystal vibrating piece pillow portion on the support material, the crystal vibrating piece 2 on the support material 5 is bonded to the support material 5 using the crystal vibrating piece bump 72. The quartz crystal resonator element 2 can be stably arranged without being inclined with respect to the mounting position. Specifically, the quartz vibrating piece pillow portion is a protrusion formed on the main surface of the support material 5 facing the quartz vibrating piece 2, and the quartz vibrating piece pillow portion on the support material shown in FIGS. 1 and 2. In the case of providing the crystal vibrating piece pillow part, it is desirable that the installation position of the pillow part for the crystal vibrating piece is in the vicinity of the other side part in the longitudinal direction of the support material 5 and in the vicinity of the intermediate part in the short direction.

  Further, in the above-described embodiment, the extraction electrodes 241 and 242 are extracted to the one end portion 27 of the one main surface 221, but the present invention is not limited to this, and it is only necessary to extract to the one main surface 221. . For example, the extraction electrodes 241 and 242 may be extracted to the one end portion 27 of the one main surface 221 and the other end portion facing the one end portion 27.

  In addition, as described above, the substrate 21 of the AT-cut crystal piece is formed into a rectangular parallelepiped having a rectangular shape in plan view, but is not limited thereto, and a notch is formed in the substrate 21. May be.

  Further, in this embodiment, the joint part 51 of the support material 5 to the crystal vibrating piece 2 and the joint parts 261 and 262 of the crystal vibrating piece 2 to the support material 5 are formed in an uneven shape, but the uneven shape is limited to this. However, if at least one of the bonding parts 51 of the support material 5 with the crystal vibrating piece 2 or the bonding parts 261 and 262 of the crystal vibrating piece 2 with the support material 5 has an uneven shape. Good. For example, the crystal resonator 1 may be configured by a combination of the base 3, the support material 5, and the crystal vibrating piece 2 as shown in FIGS.

  Specifically, in the configuration of the crystal unit 1 shown in FIG. 4, a plurality of concave shapes that are recessed with respect to the bottom portion 31 are formed in the joint portion 34 with the support material 5 provided on the bottom portion 31 of the base 3. ing. First concave base bumps 75 made of gold bumps are respectively formed on the concave inner bottom surfaces of the joint portions 34. Further, in the support material 5, a plurality of concave shapes are formed in the joint part 51 and the joint part 52, respectively, in the same manner as in the embodiment (FIGS. 1 to 3) described above. A second crystal vibrating piece bump 74 and a second base bump 76 made of gold bumps are formed on the inner bottom surfaces of the concave portions of the joint portion 51 and the joint portion 52, respectively. The quartz crystal resonator element 2 is formed with a plurality of concave shapes at the joint portions 261 and 262 of the substrate 21, respectively, and a first quartz crystal resonator piece made of gold bumps on the inner bottom surfaces of the joint portions 261 and 262. Bumps 73 are formed. Then, the support material 5 is bump-bonded to the base 3 by the FCB method via the base bump 71 by the same method as the manufacturing method described above, and the crystal vibrating piece 2 is bonded to the support material 5 via the crystal vibrating piece bump 72. Bump bonding by FCB method.

  According to the configuration of the quartz crystal resonator 1 shown in FIG. 4, in addition to the above-described operational effects of the present embodiment, the quartz crystal vibrating piece 2 and the support material 5 when the quartz crystal vibrating piece 2 is bonded to the support material 5 are used. The gap can be narrowed, and as a result, it is suitable for reducing the height of the crystal unit 1. Further, the gap between the base 3 and the support material 5 when the support material 5 is joined to the base 3 can be narrowed, and as a result, it is suitable for reducing the height of the crystal resonator 1.

  Further, in the configuration of the crystal unit 1 shown in FIG. 5, the joining portion 34 with the support member 5 provided on the bottom 31 of the base 3 is formed into a flat surface shape, and the joining portion 34 is made of a first base made of gold plating. Bumps 75 are formed. Further, the joint portions 261 and 262 of the crystal vibrating piece 2 have a flat surface shape, and the first crystal vibrating piece bump 73 made of gold plating is formed on the joint portions 261 and 262. Further, in the support material 5, a plurality of concave shapes are formed in the joint part 51 and the joint part 52, respectively, in the same manner as in the embodiment (FIGS. 1 to 3) described above. A second crystal vibrating piece bump 74 and a second base bump 76 made of gold bumps are formed on the inner bottom surfaces of the concave portions of the joint portion 51 and the joint portion 52, respectively. Then, the support material 5 is bump-bonded to the base 3 by the FCB method via the base bump 71 by the same method as the manufacturing method described above, and the crystal vibrating piece 2 is bonded to the support material 5 via the crystal vibrating piece bump 72. Bump bonding by FCB method.

  According to the configuration of the crystal resonator 1 shown in FIG. 5, in addition to the operational effects of the present embodiment described above, the configurations of the base 3 and the crystal vibrating piece 2 can be simplified.

  Further, in the above-described embodiment, the crystal vibrating piece 2 made of an AT-cut crystal piece is used as shown in FIGS. 1 to 3, but the present invention is not limited to this, and a tuning fork type as shown in FIG. Other piezoelectric vibrating pieces such as a quartz vibrating piece may be used.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention can be applied to a piezoelectric vibrator such as a crystal vibrator.

FIG. 1 is a schematic configuration diagram of a crystal resonator according to the present embodiment, and is a schematic plan view showing the inside of the crystal resonator. FIG. 2 is a schematic configuration diagram of the crystal resonator according to the present embodiment, and is a cross-sectional view taken along line AA of FIG. FIG. 3 is a schematic configuration diagram illustrating each component before the crystal resonator according to the present example is manufactured. FIG. 4 is a schematic configuration diagram of a quartz crystal resonator element according to another example of the present embodiment. FIG. 5 is a schematic configuration diagram of a quartz crystal resonator element according to another example of the present embodiment. FIG. 6 is a schematic configuration diagram of a crystal resonator according to another example of the present embodiment, and is a schematic plan view showing the inside of the crystal resonator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crystal oscillator 2 AT cut crystal vibrating piece 261,262 Joint part 3 Base 34 Joint part 4 Lid 5 Support material 51 Joint part for crystal vibrator piece 52 Base joint part 71 Base bump 72 Crystal vibrator piece bump 73 1st Bump for crystal vibrating piece 74 Bump for second crystal vibrating piece 75 Bump for first base 76 Bump for second base 8 Crystal vibrating piece

Claims (7)

A support material that holds the piezoelectric vibrating piece, a base that holds the piezoelectric vibrating piece via the support material, and a lid that is joined to the base to hermetically seal the piezoelectric vibrating piece held on the base are provided. In the piezoelectric vibration device in which the support material is bump-bonded to the base by a bump for base and the piezoelectric vibration piece is bump-bonded to the support material by a bump for piezoelectric vibration piece,
A piezoelectric vibration device, characterized in that at least one of the bonding portion of the support material to the piezoelectric vibrating piece or the bonding portion of the piezoelectric vibrating piece to the support material has an uneven shape. The piezoelectric vibration device according to claim 1,
The piezoelectric vibrating piece bump comprises a first piezoelectric vibrating piece bump and a second piezoelectric vibrating piece bump,
The bump for the first piezoelectric vibrating piece is formed at a bonding site of the piezoelectric vibrating piece,
The bumps for the second piezoelectric vibrating piece are formed at the joint portion of the support material;
The piezoelectric vibration device, wherein the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are ultrasonically bonded, and the piezoelectric vibrating piece is bump bonded to the support material. The piezoelectric vibration device according to claim 2,
At least one of the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump is a plating bump,
A piezoelectric vibrating device, wherein the piezoelectric vibrating piece is diffusion bonded to the support material by the piezoelectric vibrating piece bump. The piezoelectric vibration device according to claim 2,
The joint portion of the support material with the piezoelectric vibrating piece has an uneven shape, and the joint portion of the piezoelectric vibration piece with the support material has an uneven shape,
Furthermore, a concave shape and a convex shape are respectively formed in a bonding portion of the support material with the piezoelectric vibrating piece and a bonding portion of the piezoelectric vibrating piece with the support material,
The first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are formed in the concave shape and the convex shape, and the first piezoelectric formed in the concave shape and the convex shape. A piezoelectric vibration device, wherein the vibration piece bump and the second piezoelectric vibration piece bump are ultrasonically bonded, and the piezoelectric vibration piece is bump bonded to the pressure support material. The piezoelectric vibration device according to claim 2,
The joint portion of the support material with the piezoelectric vibrating piece has an uneven shape, and the joint portion of the piezoelectric vibration piece with the support material has an uneven shape,
Furthermore, a concave shape is formed in each of the bonding portion of the support material with the piezoelectric vibrating piece and the bonding portion of the piezoelectric vibrating piece with the support material,
The first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are formed in the concave shapes, respectively, and the first piezoelectric vibrating piece bump and the second formed in the concave shape. A piezoelectric vibrating device, wherein the piezoelectric vibrating piece bump is ultrasonically bonded and the piezoelectric vibrating piece is bump bonded to the pressure support material. A support member that holds the piezoelectric vibrating piece, a base that holds the piezoelectric vibrating piece via the support material, and a lid that is joined to the base to hermetically seal the piezoelectric vibrating piece held on the base; In the method of manufacturing a piezoelectric vibration device, the support material is bump-bonded to the base with a bump for base and the piezoelectric vibration piece is bump-bonded to the support material with a bump for piezoelectric vibration piece.
The bonding portion of the support material with the piezoelectric vibrating piece, or at least one of the bonding portions of the piezoelectric vibrating piece with the support material has an uneven shape,
A method for manufacturing a piezoelectric vibration device, comprising: bonding a bonding portion of the piezoelectric vibrating piece to a bonding portion of the support material by an FCB method using the bumps for the piezoelectric vibrating piece. In the manufacturing method of the piezoelectric vibration device according to claim 6,
The piezoelectric vibrating piece bump comprises a first piezoelectric vibrating piece bump and a second piezoelectric vibrating piece bump,
Forming a bump for the first piezoelectric vibrating piece at a bonding portion of the piezoelectric vibrating piece;
Forming a bump for the second piezoelectric vibrating piece at a joint portion of the support material;
A method of manufacturing a piezoelectric vibration device, wherein the first piezoelectric vibrating piece bump and the second piezoelectric vibrating piece bump are ultrasonically bonded, and the piezoelectric vibrating piece is bump bonded to the support material.

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