JP5092583B2 - Piezoelectric vibration device - Google Patents

Description

  The present invention relates to a piezoelectric vibration device used for electronic equipment and the like.

  In the sealing process of the surface mount type piezoelectric vibration device, a container body (base) made of a ceramic laminate having an annular bank portion with a metal film layer formed on the upper surface, and a rectangular lid made of metal And hermetically bonded by a sealing means such as a seam welding method.

  At the time of seam welding, the metallic lid is in a high temperature state, so that the temperature of the base in contact with the lid also rises due to heat conduction. However, due to the difference in thermal expansion coefficient (linear expansion coefficient) between the lid and the base, various stresses such as tensile stress are generated in the lid and the base when the seam welding is completed and the temperature is lowered to room temperature. To do. At this time, if the temperature gradient in the base is in a large state, the influence of thermal stress is increased, and cracks and cracks are likely to occur on the side surface and bottom surface of the base 1. When cracks or cracks occur, problems such as poor airtightness and deviation in oscillation frequency due to an increase in base internal stress occur. (See Figure 15)

  In order to relieve the stress, there is a base having a configuration in which a metal frame is interposed as a cushioning material between the metal film layer and the lid, but due to the miniaturization of the piezoelectric vibration device, the width of the bank portion is reduced. Since the bonding strength of the metal film layer to the base substrate is reduced, the stress generated by the shrinkage of the lid and the metal frame during the cooling process after seam welding is applied to the metal film layer, There was a problem that the metal film layer peeled off. In order to solve such a problem, Patent Document 1 discloses an electronic component storage package in which a groove-shaped notch filled with a conductor is formed from the upper end of the side surface of the base to the center.

JP 2005-183724 A

  However, in the package (base) of Patent Document 1, the brazing material that joins the metal frame and the metal film layer by the groove-shaped notch is formed in a groove shape from the joint surface between the metal frame and the metal film layer. Since the fillet is formed over the exposed surface of the conductor filled in the notch, an improvement in the bonding force can be expected, but the thickness of the metal frame is added, and this does not lead to a reduction in the height of the piezoelectric vibration device.

  The present invention has been made in view of the above points, and can suppress a temperature gradient in the base during hermetic sealing, and can achieve highly reliable hermetic sealing by using a base that also supports low profile. An object of the present invention is to provide a piezoelectric vibration device that can be used.

In order to achieve the above object, according to claim 1 of the present invention, a recess for accommodating a piezoelectric vibration element therein, an annular shape surrounding the recess and having a metal sealing member formed circumferentially on the upper surface A rectangular base in plan view made of a laminate of an insulating material comprising
At least one of the outer surface, the inner surface, and the inner surface of the bank on the long side of the base, or a combination of two or more of them, the heat conducting portion made of a metal conductor has a different width between layers. At least one or more portions are formed in the depth direction of the bank portion up to a position below the virtual line extending in the horizontal direction from the inner bottom surface of the recess, so that the lid When sealing the concave portion with a body, the heat of the upper part of the base, which has become a high temperature, can be rapidly transmitted to the lower part of the base through the heat conducting part.

  According to the above configuration, since the heat of the upper part of the base that has reached a high temperature can be conducted to the lower part of the base, the temperature gradient of the base can be suppressed.

  With the above configuration, since the concentration of various stresses applied to the base can be dispersed inside the base, occurrence of cracks in the base can be suppressed.

When joining the rectangular base and the lid by seam welding, the longer side with the longer side has longer contact time with the seam roller, so the temperature of the upper surface of the base is also higher on the longer side of the base. It becomes higher than the short side. Therefore, the temperature gradient in the base is considered to be larger on the long side. In addition, cracks may occur in structurally fragile portions of the base due to manufacturing variations of the base. However, according to the configuration of the present invention, at least one of the outer side surface, the inner side, and the inner side surface of the bank portion on the long side of the base, or a position where a combination of two or more is provided, the heat conducting unit made of a metal conductor Are formed at one or more places with different widths between the stacked layers , and at least one of the heat conducting portions extends in the depth direction of the bank portion from the inner bottom surface of the concave portion in the horizontal direction. Since it is formed to a position below the line, the heat at the top of the base is rapidly conducted toward the bottom of the base, and the temperature gradient of the base can be suppressed. Since the base temperature can be made uniform by the heat conducting part, the occurrence of cracks in the base can be suppressed.

  When the heat conducting portion is formed on the outer surface of the base bank portion, the heat of the upper portion of the base is conducted toward the lower portion of the base with diffusion (heat dissipation) to the outside. However, since the heat conducting portion is formed in the depth direction of the bank portion to a position below a virtual line extending in the horizontal direction from the inner bottom surface of the recess, the base upper portion is accompanied by heat diffusion. This heat can be diffused from the bottom surface of the base of the concave portion to the lower region. Thereby, the steepness of the temperature gradient of the base can be suppressed.

  When the heat conducting portion is formed inside the base bank portion, the heat conducting portion is surrounded by the base insulating material. Excellent heat transfer efficiency because it is conducted in the direction.

  When the heat conducting portion is formed on the inner side surface of the base bank portion, although heat loss is caused by heat dissipation, the heat dissipation is not in the external space but in the internal space, that is, in the recessed space (cavity). Since heat is released to the heat, thermal loss can be suppressed and the temperature gradient of the base can be suppressed.

  The arrangement of the heat conducting portion is formed at any one of the outer side surface, the inner side, the inner side surface of the bank portion on the long side of the base, or a combination of two or more, but the heat conduction efficiency is good. It is formed inside the long side bank portion, and is also formed at a position where one or more of the outer side surface, the inner side, and the inner side surface of the bank side portion on the short side of the base are combined. Therefore, more heat capacity can be ensured, and the effect can be expected by making the base temperature uniform.

  In addition, the number of the heat conduction portions disposed is not only one at each of the positions of the outer surface, the inside, the inner surface of the bank portion on the long side of the base, or a combination of two or more, A plurality may be provided. In particular, when a plurality of bases are provided in the bank side on the long side of the base, it is effective for suppressing the base temperature gradient.

  In addition, the heat conduction part may be in a state where a part or all of the heat conduction parts are electrically independent from the metal sealing member. For example, in the case of a base in which three ceramic green sheets are laminated, a heat conduction portion is formed only in an intermediate layer, and the metal sealing member on the upper surface of the bank portion and the heat conduction portion are not connected. May be. Even in such a structure, the heat of the metal sealing member that has reached a high temperature can be conducted to the heat conducting portion by heat conduction through the base substrate (ceramic), so that the base temperature can be made uniform. Can be planned.

  According to the said structure, since the formation amount of a heat conductive part can be decreased rather than the case where it connects with the said metal sealing member, the conductor usage-amount of a heat conductive part can be reduced.

  Furthermore, the heat conduction part includes a via hole (cylindrical hole filled with a conductor) electrically connected to the metal sealing member, and a wiring conductor between the ceramic green sheet stacks connected to the via hole. It is also possible to have a structure connected to the metal sealing member. Even with this structure, the base temperature can be rapidly uniformized.

  Furthermore, the arrangement of the heat conducting portion may be formed not only on the long side of the base but also on the short side. In this case, since the temperature gradient can be suppressed from two directions, it is more effective to make the base temperature uniform.

  As described above, since the temperature gradient of the base can be suppressed by forming the heat conducting portion, the width of the base bank portion can be reduced, and the volume of the cavity with respect to the outer dimensions of the base can be further increased. It can be secured greatly. In addition, since the cavity volume of the base can be increased, it is possible to increase the size of the piezoelectric vibration element mounted in the cavity in the base of the same external dimensions as compared with the conventional one, and the design margin increases. become. In addition, it is possible to design for further miniaturization requirements.

According to claim 2 of the present invention, the width of the heat conducting part in the layer near the metal sealing member of the base is larger than the width of the heat conducting part in the layer below the layer. And at least one of the heat conducting portions is electrically connected to the metal sealing member, and extends in the depth direction of the bank portion from the inner bottom surface of the recess in the horizontal direction. Since it is formed to a position below the line, the heat of the upper part of the base can be more efficiently conducted to the lower part of the base, and it is effective for rapid uniformization of the base temperature. This is because the width of the heat conduction part in the layer closer to the metal sealing member that reaches a high temperature during seam welding or beam welding is made larger than the width of the heat conduction part in the layer below the layer. This is because more heat capacity can be secured.

According to a third aspect of the present invention, a plurality of the heat conducting portions are formed, and an interval between the plurality of heat conducting portions is gradually widened from approximately the center of the long side bank portion to both ends of the bank portion. Since it is formed, the base temperature can be homogenized more efficiently. This is because the area around the center of the bank on the long side is considered to be a concentrated area of various stresses applied to the base by seam welding, so that more heat capacity is transferred toward the bottom of the base near the center of the bank on the long side. This is because the thermal gradient can be suppressed by being moved.

According to a fourth aspect of the present invention , the piezoelectric vibration element is accommodated in the concave portion of the base according to any one of the first to third aspects, and the lid body having a rectangular shape in plan view and the metal sealing member Is a piezoelectric vibration device characterized in that it is hermetically joined by seam welding or beam welding , and heat transmitted from the lid body to the upper part of the base via the metal sealing member on the upper surface of the base bank at the time of hermetic joining, The heat conduction part can conduct quickly toward the lower part of the base. Accordingly, the temperature gradient of the base is suppressed, and the occurrence of cracks can be suppressed by making the base temperature uniform, so that a highly reliable piezoelectric vibration device can be obtained.

  As described above, according to the present invention, the temperature gradient in the base at the time of hermetic sealing can be suppressed, and a highly reliable hermetic sealing can be performed by using the base corresponding to the low profile. A piezoelectric vibration device can be provided.

-First embodiment-
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The following embodiment shows a case where a surface-mount type crystal resonator is applied to the present invention as a piezoelectric vibration device.

  FIG. 1 is a perspective view of a base showing a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a top view of the base showing the first embodiment. Yes. FIG. 4 is a cross-sectional view of the crystal resonator in the long side direction before seam welding showing the first embodiment, and FIG. 5 is a cross-sectional view of the crystal resonator in the long side direction after seam welding showing the first embodiment. It is. 1 to 5, the external connection electrodes formed on the bottom surface of the base and the wiring conductors formed inside the base are not shown. Also, in FIGS. 4 to 5, the description of the pair of excitation electrodes formed to face the front and back surfaces of the crystal diaphragm is omitted.

  As shown in FIG. 1, a surface mount type crystal resonator base 1 applied in the present invention includes a concave portion 3 for accommodating a piezoelectric vibration element therein, and an annular bank portion 2 surrounding the concave portion 3. Is a container body made of an insulating material mainly composed of ceramic such as alumina.

  The base 1 is formed by laminating four ceramic green sheets and is composed of 1a, 1b, 1c, and 1d in order from the base bottom side (see FIG. 2). A wiring conductor (not shown) connected to an external connection electrode (not shown) formed on the bottom surface of the base 1 is formed inside the base 1.

  The upper surface of the bank portion 2 is flat, and a metal film layer 4 including a tungsten metallized layer, a nickel plating layer, and a gold plating layer is formed in a circumferential shape from the bottom as a metal sealing member. Yes. Note that molybdenum may be used instead of tungsten.

  A plurality of columnar heat conducting portions 5 are disposed inside each of the two opposing bank portions on the long side of the base 1. In the present embodiment, the heat conducting portion 5 is disposed at 6 locations per long side, that is, 12 locations along the entire long side. About the short side direction, it is arrange | positioned in three places per short side, ie, six places in the whole short side. That is, the heat conduction part is formed in 18 places in total in the base 1 whole. In FIG. 1, the formation state of the heat conducting portion 5 is indicated by a dotted line for easy understanding.

  As shown in FIG. 2, in the depth direction, the heat conducting portion 5 is connected to the metal film layer 4, passes through the inside of the bank portion 2, and extends in the horizontal direction from the inner bottom surface of the concave portion. It is formed up to a position below L, that is, the position of the upper surface of the first layer (1a) of the base 1. As for the planar direction, on the line connecting the centers of the width of the bank (hereinafter referred to as “seal path”), the central axis of the cylindrical heat conducting part is substantially coincident with the long side and the short side at regular intervals. They are arranged in line (see FIG. 3). The diameter of the heat conducting part 5 is preferably about 0.1 mmφ when the seal path is 0.2 mm.

  The heat conducting portion 5 is made of a conductor, and in this embodiment, is the same material as the wiring conductor, and tungsten or molybdenum is used. The heat conducting part 5 is formed by screen printing. Specifically, a through hole (via hole) is formed in a ceramic green sheet, and a conductor is filled in the through hole by squeegeeing, and then a plurality of ceramic green sheets are laminated and integrally formed by firing. Then, a tungsten metallized layer is formed on the upper end side of the heat conducting portion 5, that is, on the upper surface of the bank portion 2, and a metal film layer 4 is formed on the upper surface in the order of a nickel layer and a gold layer by a plating method. (See FIG. 3).

  In FIG. 2, a pair of mounting pads 9 (not shown) are formed on the inner bottom portion (upper surface of 1 b) of the base 1, and these mounting pads are formed in the interior (1 a) of the base 1. It is electrically connected to the external connection electrode formed on the bottom surface of the base (the lower surface of 1a) via a conductor. In the pair of mounting pads, for example, a metal layer is formed on the upper surface of the tungsten metallized layer by a technique such as plating in the order of nickel and gold. In the present embodiment, the mounting pad is formed in parallel with one short side on the inner bottom of the base.

  A surface-mount type crystal resonator applied in the present invention includes a rectangular parallelepiped AT-cut crystal diaphragm 6 having excitation electrodes for driving a piezoelectric vibration element formed on the front and back surfaces in a recess of the base 1. After electrically and mechanically connecting the formed mounting pad 9 via the conductive bonding material 10, the lid body 7 made of metal having a rectangular shape in plan view is placed on the metal film layer 4 on the upper surface of the base bank portion. It is obtained by mounting and airtight joining by seam welding (see FIGS. 4 to 5).

  In FIG. 4, the lid body 7 is a metallic lid body having a rectangular shape in a plan view using Kovar as a base, and nickel plating layers (not shown) are formed on the front and back surfaces of the lid body 7. Further, a brazing material 8 made of metal is formed over the entire surface of the lid 7 on the side of the joint surface with the metal film layer 4 below the nickel plating layer (joint surface side). In the present embodiment, silver brazing is used as the brazing material.

  Hereinafter, a method for manufacturing a crystal resonator to which the present invention is applied will be described. First, an appropriate amount of the conductive bonding material 10 is applied to the upper portions of the pair of mounting pads 9 by a dispenser or the like, and then the quartz diaphragm 6 sucked and held by a quartz diaphragm holding tool (not shown) is mounted. The conductive bonding material 10 is cured with the temperature profile, and the crystal diaphragm 6 and the mounting pad 9 are electrically and mechanically connected. The conductive bonding material 10 is, for example, a paste-like silicone resin conductive bonding material, but is not limited thereto, and an epoxy resin conductive bonding material or the like may be used.

  After the crystal diaphragm 6 is bonded to the mounting pad 9 via the conductive bonding material 10, the lid 7 is metal formed on the upper surface of the bank portion of the base 1 using a mounting tool (not shown). Place on the film layer 4. At this time, the lid body 7 is placed on the metal film layer 4 so that the brazing material 8 formed on the bonding surface side of the lid body 7 with the metal film layer 4 substantially matches.

  After the lid body 7 is placed on the upper surface of the base, the pair of seam rollers R is brought into contact with the substantially central portions (two locations) of the two opposite long sides of the lid body 7 for temporary fixing. The temporary fixing operation is performed in order to prevent displacement of the joining position by temporarily fixing the lid body 7 and the base 1 at two locations. The temporary fixing operation may be performed at two or more places, for example, four places (two places at regular intervals on one long side).

  After the temporary fixing, as shown in FIG. 4, the seam roller R is brought into contact with the periphery on one end side of the two opposite long sides of the lid 2, and a large current is applied to the lid 7 and the metal film layer 4. The brazing material 8 and the metal film layer 4 in the long side direction of the crystal unit 1 are sealed and bonded by rolling toward the other end side of the two long sides facing the lid body 7 while being applied. (First sealing step).

  Next, the seam roller R is brought into contact with the periphery of one end side of the two opposing short sides of the lid body 7, while applying a large current to the lid body 7 and the metal film layer 4, By rolling in the direction, the brazing material 8 and the metal film layer 4 in the short side direction are sealed and joined, and the lid 7 and the base 1 are hermetically sealed as shown in FIG. 2 sealing step). The first and second sealing steps are performed in an inert gas atmosphere.

  During the seam welding described above, heat is transferred to the base 1 through the metallic lid 7 and the metal film layer 4 that are in a high temperature state. The heat conduction unit 5 transfers the heat of the metal film layer 4 to the base 1. Heat can be rapidly transferred downward. In other words, the heat of the metal film layer 4 that has reached a high temperature can be quickly transferred to the lower part of the base (in the case of the present embodiment, around the upper surface of the first layer 1a) by the plurality of heat conducting portions 5. The temperature gradient inside can be suppressed, and the temperature of the base can be made uniform. Due to this effect, the base internal stress can be relieved, so that the occurrence of cracks can be suppressed.

  In the present embodiment, the number of the heat conducting portions 5 provided is six per long side, but is not limited thereto. That is, it may be formed at only one place or a plurality of places per long side. In this case, the formation position of the heat conduction part is preferably the center of the long side or a position close to both sides including the center of the long side. This is because the concentration of various stresses applied to the base by seam welding is dispersed inside the base. Even with such a configuration, the heat of the upper part of the base that has become high during seam welding can be rapidly conducted toward the lower part of the base, so that the temperature gradient of the base is suppressed and cracks are effectively suppressed.

  Alternatively, the number of the heat conducting parts 5 may be six or more per long side. In this case, the heat of the upper part of the base can be conducted to the lower part of the base in a larger area, so that it functions more effectively to make the base temperature uniform.

  The heat conduction portion 5 may be disposed not only on the long side of the base but also on the short side. In this case, since the temperature gradient can be suppressed from two directions, an effect can be expected by making the base temperature uniform.

  The shape of the heat conducting portion 5 is not limited to a cylinder, and may be a prismatic shape or an elliptical column shape.

  Since the temperature gradient of the base can be suppressed by the formation of the heat conducting portion 5, the base seal path can be reduced, and the volume of the recessed space (cavity) with respect to the outer dimensions of the base can be secured larger. it can. Furthermore, since the cavity volume of the base can be increased, it is possible to increase the size of the piezoelectric vibration element mounted in the cavity in the base having the same external dimensions as compared with the conventional case, and the design margin increases. In addition, it is possible to design for further miniaturization requirements.

  In addition to tungsten or molybdenum, it is also possible to use a conductor having higher thermal conductivity than these conductors, such as copper, as the conductor material of the heat conducting portion 5.

  If it is the base of this invention, since stress relaxation after seam welding can be aimed at without forming a metal frame on the upper surface of the metal film layer 4, it can contribute to the low profile of the piezoelectric vibration device. . In this embodiment, the metal frame is not used. However, the present invention can be applied to a base having a metal frame. For example, a metal frame is bonded to the metal film layer 4 via a metal bonding material, and the heat conduction part is formed in the depth direction of the bank portion in a state of being connected to the metal frame and the metal film. Just do it.

  In the case of this embodiment, sealing is performed in an inert gas atmosphere, but in the case of a vacuum atmosphere, an effect of suppressing thermal diffusion into the cavity after sealing can be expected.

  In this embodiment, seam welding is used for hermetic sealing joining between the lid and the base, but the present invention can also be applied to beam welding using a laser or an electron beam.

  In the present invention, the material of the lid is made of metal when the sealing method is seam welding, but ceramics can be used in addition to metal in the case of beam welding.

-Modification of the first embodiment-
As a modification of the embodiment of the present invention, the width (diameter) of the heat conducting portion formed in the second layer 1b and the third layer 1c and the fourth layer 1d may be different. It is. That is, it is formed so that the diameter of the heat conduction part in the fourth layer 1d located in the upper layer is larger than the diameter of the heat conduction part in the second layer 1b and the third layer 1c. This is because a larger heat capacity is secured by increasing the diameter of the heat conducting portion in the fourth layer closer to the metal film layer 4 that reaches a high temperature. Even with such a configuration, the heat of the upper part of the base that has become high during seam welding can be rapidly conducted toward the lower part of the base, so that the temperature gradient of the base is suppressed and an effect can be expected to suppress cracks.

  Furthermore, as another modification of the embodiment of the present invention, a plurality of heat conducting portions are disposed at least inside the bank on the long side, and various stresses applied to the base by seam welding are concentrated, that is, By making only the heat conducting portion near the center of the long side into an elliptical shape having a larger volume than the other heat conducting portions, it is possible to secure more heat capacity and enhance the thermal gradient suppressing effect. Furthermore, a higher thermal gradient suppression effect can also be expected by using a conductor having good thermal conductivity such as copper for the elliptical heat conducting portion.

-Second Embodiment-
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a top view of the base showing the second embodiment, and FIG. 7 is a cross-sectional view taken along line BB of FIG. In FIG. 6, the heat conduction part is displayed using both a dotted line and a fill in order to make the formation state easy to understand. In addition, about the structure similar to 1st Embodiment, while attaching | subjecting the same number and omitting a part of description, it has an effect similar to 1st Embodiment. Also in this embodiment, a case where a surface-mount type crystal resonator is applied to the present invention is shown.

  In FIG. 6, a base 11 is a laminated body of four ceramic green sheets, and is composed of 1a, 1b, 1c, and 1d in order from the bottom surface side of the base. A wiring conductor (not shown) connected to an external connection electrode (not shown) formed on the bottom surface of the base 11 is formed inside the base 11. Further, the upper surface of the bank portion 2 is flat, and a metal film layer 4 composed of three layers is formed in a circumferential shape as a metal sealing member with the same film configuration as in the first embodiment.

  As shown in FIG. 6, in the present embodiment, the heat conducting portion is formed not only inside the long-side bank 2 but also on the inner surface of the long-side bank 2. The heat conducting portion 51 formed on the inner surface of the bank portion 2 is connected to the metal film layer 4 on the upper surface of the bank portion, is formed up to the depth of the upper surface of the 1b layer, and divides the cylinder into two in the height direction. “Cylinder” shape. In the present embodiment, the heat conducting portions 5 are arranged at six locations at regular intervals inside one long side, at six locations at regular intervals on the inner wall of the long side, and thus at 12 locations in one long side unit. Yes. Therefore, there are 24 locations on the entire long side.

  Regarding the short side direction, the heat conducting portions 5 are arranged at three equal intervals per short side, at three equal intervals on the inner wall of one short side, and thus at six locations per short side unit. . In other words, the entire short side is arranged at 12 locations. Therefore, in the base 11 as a whole, heat conducting portions are formed at a total of 36 locations including the long and short sides. The plurality of heat conducting portions 5 are arranged on a line connecting the centers of the long and short side seal paths so that the central axes of the cylindrical heat conducting portions substantially coincide with each other at regular intervals. It is installed. The heat conducting portions 51 are arranged at regular intervals so that the central axis of the semi-cylinder coincides with the inner wall surface of the bank.

  In the state of ceramic green sheet, the heat conducting part 51 is formed with a plurality of circular through holes in an annular shape, filled with tungsten or molybdenum conductors in the through holes, and then passed through the diameters of the respective holes. It is formed by pressing with a circumferential line that bisects the area. In the present embodiment, the conductor material of the heat conducting unit 51 is composed of the same material as the heat conducting unit 5. In addition, the material of the heat conductive part 51 is not limited to the same material, A different material may be sufficient.

  In the case of the above configuration, since the heat capacity of the heat conducting portion can be secured more than in the case where the heat capacity is formed only inside the bank on the long side of the base, it is effective due to rapid uniformization of the temperature of the base 11. Is. Further, as shown in FIG. 7, the heat conducting portion 5 is located below the virtual line L extending from the inner bottom surface of the concave portion in the horizontal direction from the metal film layer 4, that is, the position of the base 11. Since it is formed over the upper surface of the first layer 1a, the heat of the upper part of the base that has reached a high temperature can be transferred to the lower part of the base by heat conduction. Such a configuration makes it possible to make the temperature distribution of the base uniform.

  In addition, it is preferable from the point of the thermal gradient inhibitory effect to arrange | position the heat conduction part 51 on the base inner surface at least one center periphery of the inner surface of one long side side bank. In the case of forming at one or more locations, it is preferable to form at a position close to both sides including the center of the inner surface of the long side.

-Modification of the second embodiment-
Hereinafter, a modification of the second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a top view of a base showing a modification of the second embodiment, and FIG. 9 is a cross-sectional view taken along the line CC of FIG. FIG. 10 is a cross-sectional view in the base long side direction showing another modification of the second embodiment. FIG. 11 is a top view of a base showing another modification of the second embodiment. In FIGS. 8 and 11, a part of the heat conduction part is indicated by a dotted line for easy understanding of the formation state. In addition, about the structure similar to the above-mentioned embodiment, while attaching | subjecting the same number and omitting a part of description, it has an effect similar to the above-mentioned embodiment.

  8 to 11, the base 12 is composed of a laminate of four ceramic green sheets (1a, 1b, 1c, 1d in order from the base bottom side). Moreover, the metal film layer 4 which consists of three layers with the film | membrane structure similar to the above-mentioned embodiment is formed in the upper surface of the bank part 2 as a metal sealing member at the periphery.

  In FIG. 8, the heat conduction part is formed not only inside the long side and short side bank 2 but also on the outer side of the long side and short side bank 2. . The heat conduction part 52 formed on the outer surface of the bank 2 is connected to the metal film layer 4 on the upper surface of the bank, and is formed up to the upper surface of the layer 1a. It has a shape. Then, the heat conducting portion 52 is connected to the metal film layer 4 as shown in FIG. 9, and is below the virtual line L extending in the horizontal direction from the inner bottom surface of the base recess, downward from the metal film layer. Since it is formed up to the position, that is, the upper surface of the first layer 1a of the base 12, heat of the upper part of the base that has become high can be radiated to the outside and transmitted to the lower part of the base by heat conduction. Furthermore, since the heat conduction part with good heat conduction efficiency is also formed inside the bank part 2, the temperature distribution of the base can be made uniform faster.

  Moreover, as shown in FIG. 10, it is also possible to form a heat conductive part in three places, the outer surface of the bank part 2, an inside, and an inner surface. In such a configuration, for example, the heat conduction portion 52 formed on the outer surface of the bank portion 2 is formed to the depth of the upper surface (1a upper surface) of the first layer of the base 12 from the viewpoint of heat conduction efficiency. It is preferable.

  In the case of the above configuration, the heat distribution can be ensured more and the temperature distribution in the thickness (seal path) direction can be equalized not only in the depth direction but also in the thickness (seal path) direction, so that the temperature gradient of the base is suppressed. Suitable for suppressing cracks.

  In the case where a plurality of heat conduction portions are provided in the embodiment of the present invention, the heat conduction portion formed by combining two or more of the outer side surface, the inner side, and the inner side surface of the bank portion 2 is not necessarily a seal path (bank portion width). For example, as shown in FIG. 11, the heat conduction part inside the bank and the heat conduction part on the inner side of the bank are not aligned in the seal path direction (alternately) as shown in FIG. May be.

  If it is the said structure, since the said heat conductive part is formed in the state disperse | distributed more when it sees from the bank side surface direction, the higher thermal gradient suppression effect can be anticipated.

-Third embodiment-
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. FIG. 12 is a cross-sectional view of the long side direction bank portion showing the third embodiment. In addition, about the structure similar to the above-mentioned embodiment, while attaching | subjecting the same number and omitting a part of description, it has an effect similar to 1st thru | or 2nd embodiment.

  In FIG. 12, six heat conduction portions 5 are formed inside one long side bank portion, and are connected to the metal film layer 4 on the top surface of the bank portion of the base 14 in the depth direction, and the first layer (1a ) Over the upper surface position. The intervals between the plurality of heat conducting portions 5 are not constant, and are formed so that the intervals gradually increase from near the center of the long side bank portion to near both ends of the bank portion. In other words, the gap is narrow in the vicinity of the center of the bank on the long side, and conversely in the vicinity of both ends of the bank on the long side, the gap is wide.

  In the above configuration, since the vicinity of the center of the bank on the long side is considered to be a concentrated area of various stresses applied to the base by seam welding, more heat capacity is placed near the center of the bank on the long side. The purpose is to suppress the thermal gradient by heat transfer to. With the above configuration, the base temperature can be made more efficient. In addition, the space | interval between heat conduction parts can be set arbitrarily, and is not limited to the form shown in FIG.

-Modification of the third embodiment-
A modification of the third embodiment will be described with reference to FIG. FIG. 13: is sectional drawing of the bank part of the base long side direction which shows the modification of 3rd Embodiment. In addition, about the structure similar to the above-mentioned embodiment, while attaching | subjecting the same number and omitting a part of description, it has an effect similar to the above-mentioned embodiment.

  As shown in FIG. 13, wiring conductors 16 are formed in the horizontal direction between the ceramic green sheet stacks of the base 15, and a part of the plurality of heat conducting portions 5 is connected to the wiring conductors 16 to be in a conductive state. The heat of the upper part of the base can be conducted not only in the vertical direction but also in the horizontal direction. Here, the wiring conductor 16 may be grounded via a wiring conductor inside the base connected to an external connection terminal formed on the bottom surface of the heat conducting portion 5 or the base 15.

  According to the above configuration, since the temperature gradient can be relaxed in both the vertical direction and the horizontal direction, an effect can be expected by making the temperature of the base uniform.

  In the above configuration, the connection between the wiring conductor 16 and the heat conducting portion 5 may be a structure in which the formation depth is changed between adjacent heat conducting portions as shown in FIG. Alternatively, a structure (single depth) in which all the heat conducting portions are connected to the wiring conductor 16 may be used.

  As another modification of the embodiment of the present invention, as shown in FIG. 14, in the base 17, a columnar heat conduction portion 5 is formed between the second layer 1 b and the fourth layer 1 d. The diameter of the heat conduction part formed in the second layer 1b and the fourth layer 1d may be larger than the diameter of the heat conduction part of the third layer 1c. Or you may form so that the diameter of the heat conductive part of the 3rd layer 1c and the 4th layer 1d may become larger than the diameter of the heat conductive part of the 2nd layer 1b.

  In the embodiment of the present invention, an AT-cut crystal resonator is cited as the piezoelectric vibration device. However, the present invention can also be applied to the manufacture of tuning fork crystal resonators and other cut crystal resonators as other examples. . Furthermore, after mounting the IC on the base bottom of the base, the IC connection terminal and the pad electrode formed on the base bottom of the base are electrically connected by wire bonding, face-down bonding, etc., and the piezoelectric vibration element is mounted above it. The present invention can also be applied to the manufacture of an oscillator having the above structure, or an oscillator in which the positional relationship between the IC and the piezoelectric vibration element is inverted. Further, the piezoelectric vibration element accommodated in the piezoelectric vibration device is not limited to a single one, and a plurality of piezoelectric vibration elements may be accommodated.

  The present invention is also applicable to a manufacturing method using an aggregate substrate in which a plurality of lids or bases are integrally formed in a matrix.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, 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.

  It can be applied to mass production of piezoelectric vibration devices.

It is a perspective view of the base which shows the 1st Embodiment of this invention. It is sectional drawing in the AA of FIG. It is a base top view showing a 1st embodiment of the present invention. It is sectional drawing of the crystal oscillator long side direction before seam welding which shows 1st Embodiment. It is sectional drawing of the crystal oscillator long side direction after the seam welding which shows 1st Embodiment. It is a top view of the base which shows the 2nd Embodiment of this invention. It is sectional drawing in the BB line of FIG. It is a top view of the base which shows the modification of the 2nd Embodiment of this invention. It is sectional drawing in CC line of FIG. It is sectional drawing of the long side direction of the base which shows the modification of the 2nd Embodiment of this invention. It is a top view of the base which shows the other modification of the 2nd Embodiment of this invention. It is sectional drawing of the long side direction bank part which shows the 3rd Embodiment of this invention. It is sectional drawing of the long side direction bank part which shows the modification of 3rd Embodiment. It is sectional drawing of the long side direction bank part which shows the other modification of 3rd Embodiment. It is sectional drawing of the long side direction of the conventional crystal oscillator.

DESCRIPTION OF SYMBOLS 1, 11, 12, 13, 14, 15, 17 Base 2 Bank part 3 Recessed part 4 Metal film layer 5, 51, 52 Thermal conduction part 6 Crystal diaphragm 7 Lid 8 Brazing material

Claims (4)

The planar view which consists of a laminated body of the insulating material which comprises the recessed part for accommodating a piezoelectric vibration element inside, and the cyclic | annular dam part which surrounded the said recessed part and the metal sealing member was formed in the upper surface at the upper surface A rectangular base,
At least one of the outer surface, the inner surface, and the inner surface of the bank on the long side of the base, or a combination of two or more of them, the heat conducting portion made of a metal conductor has a different width between layers. More than one part is formed, and at least one or more is formed in the depth direction of the bank portion up to a position below a virtual line extending in the horizontal direction from the inner bottom surface of the recess. And base. The width of the heat conduction part in the layer close to the metal sealing member of the base is formed to be larger than the width of the heat conduction part in the layer below the layer. The base according to claim 1. A plurality of the heat conducting portions are formed, and the interval between the plurality of heat conducting portions is formed so as to gradually increase from approximately the center of the long side bank portion to both ends of the bank portion. The base according to any one of claims 1 to 2. The piezoelectric vibration element is accommodated in the concave portion of the base according to any one of claims 1 to 3, and the lid body having a rectangular shape in plan view and the metal sealing member are hermetically joined by seam welding or beam welding. A piezoelectric vibration device characterized by that.

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