JP2008109430A - Piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric device capable of increasing the airtightness of a package even though a sealant flows to thecorner part of a cover. <P>SOLUTION: In the piezoelectric device, a piezoelectric vibrating reed is housed in the package 36 having an opening 33, and the opening 33 is sealed by the cover 39. The cover 39 is formed in such a light-transmittable manner material 56 is connected to an inner surface of a framed metal body 55, and the metal body 55 is connected to an end face 68 of an opening part side of the package 36 by using a sealant 46 made of a metal material. A hole or a notch 60 is provided at a part of a corner part where the sealant 46 is stuck. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric device in which a package containing a piezoelectric vibrating piece is sealed with a lid.

  In small information devices such as HDDs (hard disk drives), mobile computers, or IC cards, mobile communication devices such as mobile phones or paging systems, and measuring devices such as gyro sensors, piezoelectrics are used inside packages. Piezoelectric devices such as piezoelectric vibrators and piezoelectric oscillators that house a resonator element are widely used.

FIG. 11 is a schematic longitudinal sectional view of a conventional piezoelectric device (see, for example, Patent Document 1).
The piezoelectric device 1 in this figure contains a piezoelectric vibrating piece 3 inside a package 2 and seals the package 2 with a lid 4. The lid 4 has a glass 6 for frequency adjustment fitted in a part of the metal body 5. That is, by heating when the lid 4 is bonded to the package 2, gas is generated from the adhesive 8 for bonding the piezoelectric vibrating piece 3 to the package 2, thereby affecting the vibration characteristics of the piezoelectric vibrating piece 3. Effect. Therefore, even after the lid 4 is bonded to the package 2, the laser beam L is transmitted through the glass 6 provided on a part of the lid 4 to irradiate the piezoelectric vibrating reed 3, and the mass reduction method is used. The frequency is adjusted.

In this regard, if the piezoelectric device 1 is further reduced in size, the bonding area between the metal body 5 and the glass 6 constituting the lid body 4 is reduced, which may hinder airtight reliability. Therefore, if the portion of the glass 6 is enlarged and the metal body 5 is made into a frame shape, the contact area between the peripheral side surface of the glass 6 and the inner surface of the metal body 5 is increased and the bonding strength is increased. Airtightness can be improved.
However, when the metal body 5 is formed in a frame shape, the molten sealing material 9 for joining the package 2 and the metal body 5 does not spread significantly as shown in FIG. As shown in the cross-sectional view of the frame-shaped portion when the frame is formed into a frame shape, it was found that the gas flows into the corner portion 4a and accumulates. If it does so, the location with the large thickness of the sealing material 9 and a small location generate | occur | produce, and there exists a possibility that it may leak in the location with the small thickness of the sealing material 9.

FIG. 12 is a plan view illustrating a conventional piezoelectric device 10 conceived for preventing such a sealing material 9 from accumulating in a corner portion, in which the lid is removed and the opening side of the package is illustrated. Yes (see, for example, Patent Document 2).
The piezoelectric device 10 is configured such that the package 12 is sealed with a glass lid (not shown), and a low melting point glass for bonding a glass lid to the end surface of the opening of the package 12. 16 is applied. And this low melting glass 16 consists of two layers, the 1st layer 16a is apply | coated to the perimeter of an end surface, and the 2nd layer 16b is apply | coated to the area | region except the corner | angular part 12a, Thereby, it is more than necessary to the corner | angular part 12a. Further, the low melting point glass 16 is prevented from agglomerating.

Publication of Japanese Utility Model Publication No.57-43628 Japanese Laid-Open Patent Publication No. 2005-26411

However, in the piezoelectric device 10 shown in FIG. 12, even if the low melting point glass 16 is not applied to the corner portion 12a, the low melting point glass 16 may flow into the corner portion 12a when melted. May accumulate in the corner 12a.
In particular, as shown in a diagram surrounded by a dotted line in FIG. 11, when the portion of the lid that is joined to the package 2 is made of the metal body 5, the sealing material 9 made of the metal material wets and spreads on the metal body 5. For this reason, the risk of accumulating in the corner 4a increases.

  An object of this invention is to provide the piezoelectric device which can improve the airtightness of a package, even if a sealing material flows into the corner | angular part of a cover body.

  According to the first aspect of the present invention, there is provided a piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package having an opening and the opening is sealed by a lid, the lid having a frame The metal body is formed by bonding a light transmitting material to the inner surface of the metal body, and the metal body is bonded to the end surface on the opening side of the package using a sealing material made of a metal material. This is achieved by a piezoelectric device having a hole or notch in a part of a corner to which the sealing material adheres.

According to the configuration of the first invention, the lid is formed by joining a light-transmitting material to the inner surface of the frame-shaped metal body, and the metal body is made of a metal material. Is used to bond to the end face of the package on the opening side. If it does so, the sealing material which consists of a fuse | melted metal material will flow toward the corner | angular part of a metal body in the case of the heating of lid | cover sealing. However, the metal body has a hole or notch in a part of the corner to which the sealing material adheres. Therefore, it is possible to prevent such a situation that the hole or notch accommodates excess sealing material flowing into the corner portion and the corner portion of the lid body floats from the other portion.
Thus, according to the present invention, it is possible to provide a piezoelectric device that can improve the hermeticity of the package even when the sealing material flows into the corner of the lid.

A second invention is characterized in that, in the configuration of the first invention, the hole or the notch is increased in accordance with a location where the adhesion amount of the sealing material increases.
According to the structure of 2nd invention, a hole or a notch is large according to the location where the adhesion amount of a sealing material increases. Therefore, even if the amount of the sealing material to be attached varies depending on the corner portion, the sealing material can be accommodated according to the different amount, and the height of the lid can be more accurately aligned.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the metal body includes a plate-like bottom portion joined to an end surface on the opening side of the package, and a wall provided above the periphery of the bottom portion. And a material that transmits the light is bonded to the upper surface of the bottom portion and the inner surface of the wall portion.
According to the configuration of the third invention, the metal body has a plate-like bottom part joined to the end face on the opening side of the package, and a wall part provided above the periphery of the bottom part, and an upper surface of the bottom part. And the material which permeate | transmits light is joined to the inner surface of a wall part. Therefore, a solid lid can be formed by, for example, increasing the joint area with the material that transmits light by making the shape of the inner surface of the metal body substantially L-shaped.

According to a fourth invention, in the configuration of the third invention, the hole or notch penetrates in a thickness direction of the bottom portion.
According to the configuration of the fourth invention, since the hole or notch penetrates in the thickness direction of the bottom portion, it is easy to process even if the bottom portion is thin. Further, since the hole or notch is formed deeper by penetrating, the hole or notch sufficiently exhibits a function as an escape path for the excess sealing material.

According to a fifth aspect of the present invention, in any one of the third and fourth aspects, the height (T) of the wall is at least three times the thickness (t) of the bottom, and the bottom The width dimension (L) is not less than the height dimension (T) of the wall portion.
According to the configuration of the fifth aspect of the invention, the width dimension (L) of the bottom portion is made equal to or larger than the height (T) of the wall portion, thereby improving the strength against the stress of the lid sealing, and the package Can improve the airtightness. Further, by setting the height (T) of the wall part to at least three times the thickness dimension (t) of the frame body, it is possible to ensure the bonding strength between the light transmitting material and the metal body.

According to a sixth invention, in any one of the first to fifth inventions, the sealing material is an Au—Ge alloy.
According to the configuration of the sixth invention, the sealing material is an Au—Ge alloy. Therefore, since the Au—Ge alloy is a low melting point metal, it is possible to suppress an adverse effect on the adhesive or the like in the package when the lid sealing is heated. Moreover, lead-free can also be achieved by the Au—Ge alloy. In addition, the Au—Ge alloy is more likely to accumulate at the corners when the lid is sealed than other metal materials. However, according to the first to fifth inventions, the corners of the lid body floats from other parts. It is possible to improve the airtightness of the package.

  According to a seventh aspect of the present invention, there is provided a piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package having an opening, and the opening is sealed by a lid, wherein the lid is A light-transmitting material is bonded to the inner surface of the frame-shaped metal body, and the metal body is formed on the end surface on the opening side of the package using a sealing material made of a metal material. The width dimension of the area | region which is joined and adheres to the said sealing material is achieved by the piezoelectric device which becomes small according to the location where the adhesion amount of the said sealing material increases.

  According to the structure of 7th invention, the cover body is formed by joining the material which permeate | transmits light to the inner surface of the metal body made into frame shape, and the metal body is a sealing material which consists of a metal material. Is used to bond to the end face of the package on the opening side. Then, when the lid is sealed, more molten sealing material adheres toward the corner of the metal body. However, in the metal body, the width dimension of the region adhering to the encapsulant is reduced according to the location where the amount of encapsulant attached increases. If it does so, since the sealing material which consists of metal materials will wet and spread only to the part of a metal body, the adhesion amount will decrease, so that the width dimension of a metal body is small. Therefore, restrict the amount of sealing material itself to a corner or other location where the amount of sealing material tends to increase, and distribute the thickness of the sealing material between the lid and the package uniformly. Can do.

1 and 2 show a piezoelectric device 20 according to a first embodiment of the present invention, in which FIG. 1 is a schematic plan view of the piezoelectric device 20, and FIG. 2 is a schematic cross-sectional view taken along line AA of FIG. . Note that the electrodes provided on the surface of the piezoelectric vibrating piece are not shown in the drawing so that the drawing is not complicated. Further, in FIG. 1, the region excluding the peripheral edge of the lid body 39 is a transparent body as will be described later, and therefore, the inside thereof is seen through.
In these drawings, a piezoelectric vibrator is illustrated as an example of the piezoelectric device 20, and a piezoelectric vibrating piece 32 is accommodated inside a package 36 serving as a storage container.

The package 36 has an opening 33 on the upper side, and is a box shape formed in a rectangular shape as a whole. For example, the package 36 is formed by molding an aluminum oxide ceramic green sheet as an insulating material. The substrates are formed by sequentially laminating and then sintering.
In the case of this embodiment, as shown in FIG. 2, the first substrate 36a and the second substrate 36b are stacked in this order from the top, and the first substrate 36a has a predetermined hole formed inside thereof. Thus, a predetermined internal space S1 is formed inside when stacked. This internal space S1 is a housing space for housing the piezoelectric vibrating piece 32.

Further, after mounting the piezoelectric vibrating piece 32 inside the package 36, the first substrate 36a has a lid 39 bonded to the end surface 68 on the opening 33 side, whereby the opening 33 is sealed, The internal space S1 is a nitrogen atmosphere or a vacuum atmosphere.
The shape of the lid 39 in plan view is substantially rectangular as a whole in accordance with the planar shape of the package 36. Even after the lid is sealed, in order to enable the frequency adjustment by the method of changing the mass of the piezoelectric vibrating piece 32 with the laser light L, the region facing the metal film 48 of the piezoelectric vibrating piece 32 is It is made of a material that transmits the laser beam L. In the case of this embodiment, the region facing the entire opening 33 of the package 36 is a material 56 that transmits the laser light L.
The configuration of the lid 39 and the joint structure between the package 36 and the lid 39 will be described in detail later.

  On the surface exposed to the internal space S1 of the second substrate 36b, for example, an electrode portion 31 formed by nickel plating and gold plating on a tungsten metallization is provided. The electrode unit 31 is electrically connected to the mounting terminal 33 and supplies a driving voltage. Then, a conductive adhesive 43 is applied on the electrode portion 31, and fixing arms 37 and 38 (to be described later) of the piezoelectric vibrating piece 32 are placed on the conductive adhesive 43. The piezoelectric vibrating piece 32 is bonded to the package 36 by heating and curing 43. The conductive adhesive 43 preferably uses a flexible silicone-based conductive adhesive or the like.

As the piezoelectric vibrating piece 32, a piezoelectric material such as quartz, lithium tantalate, or lithium niobate cut into a tuning fork, strip, square, mesa, or inverted mesa can be used. In the case of this embodiment, a so-called tuning fork type piezoelectric vibrating piece cut into a tuning fork shape is used for the piezoelectric vibrating piece 32. In order to obtain a required performance by forming a small size, the piezoelectric vibrating piece 32 has a shape as illustrated in particular. It has become.
That is, the piezoelectric vibrating piece 32 was branched so as to extend from the pair of vibrating arms 34 and 35 extending in parallel with each other, the base 51 supporting the pair of vibrating arms 34 and 35, and the base 51. Fixing arms 37 and 38 are provided.

The vibrating arms 34 and 35 are respectively formed with bottomed long grooves 34a and 35a extending in the longitudinal direction, and excitation electrodes (not shown) having different polarities in the long grooves 34a and 35a and on the side surfaces, respectively. Thus, the vibrating arms 34 and 35 are excited so as to increase the electric field efficiency.
Further, metal films 48 and 48 for frequency adjustment are formed at the distal ends of the vibrating arms 34 and 35 away from the base 51. The metal films 48 are changed in the frequency adjustment step after the lid is sealed by irradiating the laser beam L, thereby reducing the mass thereof and increasing the frequency. The metal films 48 and 48 can be formed simultaneously with the same structure when forming the excitation electrode.

The base 51 is a portion for supporting the pair of vibrating arms 34 and 35, and excitation electrodes (not shown) for exciting the vibrating arms 34 and 35 are routed on the front and back surfaces thereof so as not to be short-circuited. Has been.
Furthermore, the base 51 of this embodiment is also a portion for supporting a plurality of fixing arms 37 and 38 for joining the piezoelectric vibrating piece 32 to the package 36 side.

The fixing arms 37 and 38 are portions formed so that the joint portion of the piezoelectric vibrating piece 32 with the package 36 is separated from the vibrating arms 34 and 35 rather than the base portion 51. Specifically, the fixing arms 37 and 38 are formed so as to extend from the end of the base 51 opposite to the vibrating arms 34 and 35 to both sides in the width direction (X direction in FIG. 1). It is bent at a substantially right angle so as to be parallel to the vibrating arms 34 and 35.
The fixing arms 37 and 38 are provided with electrode patterns (not shown) formed integrally with excitation electrodes (not shown) provided on the vibrating arms 34 and 35, respectively. The electrode pattern portion (not shown) is electrically connected to the electrode portion 31 on the package 36 side by the conductive adhesive 43.

Here, as shown in FIG. 2, the lid body 39 for sealing the piezoelectric vibrating piece 32 is formed by joining a light transmitting material 56 to the inside of a metal body 55 having a frame shape as a whole. The bottom surface 55 c of the metal body 55 is joined to the package 36. In the present embodiment, the material 56 that transmits light is a glass material such as borosilicate glass containing an oxide (hereinafter simply referred to as “glass”).
Thus, the piezoelectric device 20 uses the metal body 55 for the lid 39 to ensure the bonding strength between the lid 39 and the package 36. That is, the conventional lid is formed of a glass material so that the frequency can be adjusted after the lid is sealed. Therefore, the conventional lid is bonded to the package using low melting point glass. And in low melting glass, it became difficult to ensure the joint strength of a cover body and a package with the sealing margin which is an end surface of the opening part side of a package becoming small. Therefore, as shown in FIG. 2, the region of the lid 39 facing the end surface 68 on the opening 33 side of the package 36 is a metal body 55, and the metal body 55 is used with a sealing material 46 made of a metal material. By joining to the package 36, the joining strength between the lid 39 and the package 36 can be secured.

  Specifically, the metal body 55 has a plate-like bottom portion 55a joined to the end surface 68 on the opening 33 side of the package 36, and a wall portion 55b provided above the periphery of the bottom portion 55a. The cross section is substantially L-shaped, and the glass 56 is bonded to the upper surface 55e at the bottom and the inner surface of the wall 55b. Thereby, the joint strength between the metal body 55 and the glass 56 is improved. That is, the glass 56 is supported in the vertical direction on the upper surface (substantially L-shaped inner bottom portion) 55 e of the bottom portion 55 a of the metal body 55. Further, as shown in FIG. 2, the glass 56 is sandwiched between the wall portions 55b and 55b on both sides, and is regulated so as not to move in the horizontal direction. In addition, since the cross section in the width direction of the metal body 55 is substantially L-shaped, the bonding area between the metal body 55 and the glass 56 is increased.

  The metal body 55 of the present embodiment is made of an Fe-based metal such as Kovar or 42 alloy, and after an oxide film is formed on the inner surface of the metal body 55, a borosilicate glass containing an oxide. It joins with glass 56, such as. Therefore, when the glass 56 is heated and melted and bonded to the metal body 55, diffusion bonding is promoted between the oxide film on the inner surface of the metal body 55 and the oxide contained in the glass, and the metal body 55 and the glass The bonding strength with 56 can be improved.

Moreover, the height dimension (T) of the wall 55b of the metal body 55 is set to be three times or more the thickness dimension (t) of the bottom 55a. In FIG. 2, the thickness dimension (t) of the bottom 55a is 0.05 mm, and the height dimension (T) of the wall 55b is 0.15 mm or more. Thereby, the contact area of the surrounding side surface of the glass 56 and the inner surface of the wall part 55b is ensured, and the joining strength of the glass 56 and the metal body 55 is ensured.
In addition, about the wall part 55b, the thermal expansion coefficient of the sealing material 46 is enlarged compared with the thermal expansion coefficient of the metal body 55, and the glass 56 is made of the wall part 55b of the metal body 55 at the time of cooling in the lid sealing process. In order to effectively enhance the bonding strength between the metal body 55 and the glass 56 by tightening, the inner surface of the wall portion 56 is within the range of the end surface 68 on the opening 33 side of the package 36 in the horizontal direction (left-right direction in FIG. 2). (Disposed above the end face 68).

  Furthermore, as shown in FIG. 3 showing the relationship between the width dimension (L) of the bottom 55a / the height dimension (T) of the wall 55b and the bonding strength (N) with the package, the height of the wall 55b. In view of the fact that the strength (N) against the stress of lid sealing is increased when the width dimension (L) of the bottom 55a is made larger than the dimension (T), the width dimension (L) of the bottom 55a of the metal body 55 is increased. The height dimension (T) of the wall portion 55b is set to be equal to or larger. That is, when the lid sealing strength (N) is 20 N or less shown in FIG. 3, there is a possibility of leakage or the like, so that L / T is set to 1 or more, and the bottom portion in the case of FIG. 1 and FIG. The width dimension (L) of 55a is substantially the same as the width of the opening-side end face 68 of the package 36. Thereby, the airtightness with respect to sealing stress can be improved.

As shown in FIG. 1, the metal body 55 has a hole or notch 60 at a part of a corner to which the sealing material 46 made of a metal material adheres.
As shown in FIG. 4 which is a sectional view taken along the line B-B in FIG. 1, the hole or notch 60 is an accommodating portion for storing the sealing material 46 that has flowed to the corner when the lid is sealed. is there. That is, in the step of sealing the package 36, for example, a sealing material having a seam ring shape having a thickness of 20 to 40 μm is placed on the end surface 68 on the opening 33 side of the package 36. The lid 39 is placed so as to face each other, and seam welding is performed, or heating is performed while applying a load from above. For this reason, the sealing material 46 tends to flow and concentrate at the corners, and the concentrated portion is accommodated in the hole or notch 60.

The hole or notch 60 of this embodiment is formed so as to cut out the inner side surface of the bottom 55 a of the metal body 55.
Further, as shown in FIG. 5 which is a partial cross-sectional view according to the modified example of FIG. 4, the hole or notch 60 may be a bottomed hole or notch without penetrating the bottom 55a. Preferably, as shown in FIG. 4, the metal body 55 may penetrate through the bottom 55 a in the thickness direction. This facilitates processing even when the bottom 55a is as thin as 0.05 mm. Moreover, since it forms deeper by penetrating the hole or notch 60, it is possible to accommodate more sealing material 46 that has flowed to the corners.

  Further, the shape of the hole and the notch 60 is not limited to the shape shown in FIG. 1, and for example, as shown in FIGS. 6A and 6B which are schematic bottom views of the lid 39. Of course, the inner side surface of the bottom 55a at the corner may be cut out in a square shape, or a circular hole provided at the center of the bottom 55a at the corner.

Note that a low melting point metal is used for the sealing material 46. Here, the low melting point metal means a temperature lower than the melting temperature of the conductive adhesive 43 for mounting the piezoelectric vibrating piece 32, and generally refers to a metal having a melting point of 200 ° C. to 400 ° C. Therefore, even if the sealing material 46 is heated at the time of sealing the lid, adverse effects on the conductive adhesive 43 can be suppressed.
Specifically, in order to make the sealing material 46 a low melting point metal, an Au—Su alloy, an Au—Si alloy, or the like can be used, but an Au—Ge alloy is preferably used. In the case of this embodiment, the Au—Ge alloy Au / Ge compounding ratio is 89 to 87 wt% Au and 11 to 13 wt% Ge, and the melting point is about 356 ° C. In addition, since this Au—Ge alloy is used, as shown in a diagram surrounded by a one-dot chain line in FIG. 2, Ni (in order) from the metal body 55 side as an underlayer 61 is formed on the surface of the Fe-based metal body 55. The film thickness is 1 to 5 μm) and Au (the film thickness is 0.01 to 0.5 μm) are deposited or sputtered. In addition, the package 36 is also metallized as an underlayer 63 in this order from the package 36 side, and Ni and Au are deposited or sputtered.

  By using the Au—Ge alloy in this manner, various good effects are exhibited for the present embodiment. For example, since the Au—Ge alloy does not contain lead, no harmful lead is generated even if it is discarded, and the width of the end face 68 on the opening side of the package 36 is extremely small, for example, 200 μm or less. Even if there is, it is possible to exert a bonding force. There are Au-Sn alloys and the like that can be made lead-free and can exhibit bonding force even if the width of the opening side end face 68 of the package 36 is small. We cannot guarantee if you do. In other words, due to the fact that solder having a higher melting point than before has been used due to lead-free electronic component mounting, a temperature of about 320 ° C. is usually applied to the piezoelectric device 20 in the repair process. For this reason, there is a possibility that an Au—Sn alloy having a melting point of about 280 ° C. cannot withstand the repair process. Even if the internal space S1 of the package 36 is in a vacuum atmosphere, if it is an Au—Ge alloy, it is difficult to leak due to external pressure.

  The piezoelectric device 20 according to the first embodiment of the present invention is configured as described above, and the metal body 55 of the lid 39 has a hole or a notch in a part of the corner to which the sealing material 46 adheres. 60. Therefore, this hole or notch 60 serves as an escape path for excess sealing material that has flowed to the corners, and can prevent a situation in which the corners of the lid 39 are floated from other parts.

FIG. 7 is a schematic bottom view of a lid 70 used in the piezoelectric device as a modification according to the first embodiment of the present invention. In this figure, the same components as those of the piezoelectric device 20 of FIGS. 1 to 6 are denoted by the same reference numerals, and redundant description will be omitted, and differences will be mainly described.
The lid 70 of the piezoelectric device is different from the first embodiment only in the holes or notches provided in the lid 70.

In other words, the sealing material 46 (see FIG. 2) adheres relatively easily and relatively less in the corner region where the amount of adhesion is larger than the region of the metal body 55 having the straight portion. It was found that there was a place. Therefore, the hole or notch 60 provided in the lid 70 is enlarged according to the location where the amount of the sealing material attached increases.
In the case of FIG. 7, a plurality of holes 60 are formed in each of the plurality of corners. And since most sealing material tends to adhere to the area | region of the corner | angular part on the diagonal V of the cover body 70, the hole 60a on the diagonal V is the largest among several holes 60, and the hole of the both sides 60b is formed smaller than the hole 60a.

  In addition, although the hole 60 formed in each corner | angular part of FIG. 7 consists of several large and small circular holes 60a and 60b, this invention is not limited to this. For example, as shown in FIG. 8 which is a modified example of FIG. 7, a single hole 60 may be formed in each of the plurality of corners. The opening area of the portion where the sealing material easily adheres is the largest, and the opening area gradually decreases toward both sides.

  The modification according to the first embodiment of the present invention is configured as described above, and the size of the hole or notch 60 is adjusted in accordance with the amount of sealing material attached. Therefore, even if the amount of the sealing material to be attached varies depending on the corner portion, the sealing material can be accommodated according to the different amount, and the height of the lid 70 can be more accurately aligned.

FIG. 9 is a schematic bottom view of a lid 72 used in the piezoelectric device according to the second embodiment of the present invention. In this figure, the same components as those of the piezoelectric device 20 of FIGS. 1 to 6 are denoted by the same reference numerals, and redundant description will be omitted, and differences will be mainly described.
The lid 72 of this piezoelectric device is the first embodiment only for the lid 72.

That is, the lid 72 in FIG. 9 does not have the holes and notches described in FIGS. 1 to 6, and the width dimension of the region (the bottom portion 55a of the metal body 55) to which the sealing material (not shown) is attached. The amount of the sealant attached is small depending on the location where the amount tends to increase.
Specifically, the width dimension of the bottom portion 55a of the frame-shaped metal body 55 is adjusted not only at the corner portions but also around the entire circumference. As shown in FIG. The width W1 in the vicinity of the center is the largest, the width is gradually narrowed toward the corner, and the width W2 on the diagonal V is the smallest.

  Note that the width of the bottom 55a of the metal body 55 in FIG. 9 decreases in an equal manner as it goes from the center toward the corner, but the present invention is not limited to this, and the amount of adhesion of the sealing material to the end. Therefore, it is preferable to determine the width. For example, as shown in FIG. 10 which is a modified example of FIG. 9, the amount of adhesion increases with a predetermined ratio as the sealing material moves from the center toward the corners for each side of the bottom portion 55a having a square frame shape. In accordance with the ratio, the width W may be decreased from the center toward the corner.

  The second embodiment of the present invention is configured as described above, and the metal body 55 has a width dimension of the bottom 55a that is reduced in accordance with a location where the amount of sealing material attached tends to increase. In this case, the lid 72 is made of glass 56 except for the metal body 55, and the sealing material wets and spreads only on the metal body 55. Therefore, the smaller the width dimension of the bottom portion 55a, the smaller the adhesion amount of the sealing material. . Therefore, the amount of the sealing material flowing to the corner itself is limited, and the thickness of the sealing material between the lid 72 and the package can be uniformly distributed to effectively prevent leakage. In the case of the second embodiment, since the width is adjusted not only at the corners of the metal body 55 but around the entire circumference, the thickness of the sealing material can be made uniform with higher accuracy.

  The present invention is not limited to the above-described embodiment. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.

1 is a schematic plan view of a piezoelectric device according to a first embodiment of the present invention. The AA line schematic sectional drawing of FIG. The figure which showed the relationship between the width dimension of the bottom part of a metal body / the height dimension of a wall part, and joining strength with a package. FIG. 3 is a sectional view taken along line BB in FIG. 1. The fragmentary sectional view which concerns on the modification of FIG. The schematic bottom view of a cover body. It is a 1st modification concerning the 1st Embodiment of this invention, Comprising: The schematic bottom view of the cover body used for a piezoelectric device. FIG. 8 is a schematic bottom view of a lid according to a modification example of FIG. 7. The schematic bottom view of the cover used for the piezoelectric device concerning the 2nd Embodiment of this invention. FIG. 10 is a schematic bottom view of a lid according to a modification of FIG. 9. The schematic longitudinal cross-sectional view of the conventional piezoelectric device. It is another example of the conventional piezoelectric device, Comprising: The top view of the state before joining a cover body to a package.

Explanation of symbols

  20 ... Piezoelectric device, 32 ... Piezoelectric vibrating piece, 33 ... Opening, 36 ... Package, 39, 70, 72 ... Lid, 46 ... Sealing material, 55 ... -Metal body, 55a ... bottom, 55b ... wall, 56 ... light transmitting material (glass), 60 ... hole or notch

Claims (7)

A piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package having an opening, and the opening is sealed by a lid,
The lid is formed by joining a material that transmits light to the inner surface of a metal body having a frame shape,
The metal body is bonded to an end face on the opening side of the package using a sealing material made of a metal material, and has a hole or a notch in a part of a corner portion to which the sealing material adheres. A piezoelectric device characterized by that.   2. The piezoelectric device according to claim 1, wherein the hole or the notch is increased in accordance with a portion where the adhesion amount of the sealing material is increased. The metal body has a plate-like bottom portion joined to an end surface on the opening side of the package, and a wall portion provided above a peripheral edge of the bottom portion, and is provided on an upper surface of the bottom portion and an inner surface of the wall portion. The piezoelectric device according to claim 1, wherein the light transmitting material is bonded.   The piezoelectric device according to claim 3, wherein the hole or notch penetrates in the thickness direction of the bottom portion.   The height dimension (T) of the wall portion is not less than three times the thickness dimension (t) of the bottom portion, and the width dimension (L) of the bottom portion is not less than the height dimension (T) of the wall portion. The piezoelectric device according to claim 3 or 4, characterized by the above.   The piezoelectric device according to claim 1, wherein the sealing material is an Au—Ge alloy. A piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package having an opening, and the opening is sealed by a lid,
The lid is formed by joining a material that transmits light to the inner surface of a metal body having a frame shape,
The metal body is bonded to an end surface on the opening side of the package using a sealing material made of a metal material, and a width dimension of a region attached to the sealing material is an adhesion amount of the sealing material. Piezoelectric device, characterized in that it becomes smaller according to the number of points where the number increases.

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