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JP-7856844-B1 - Packages and piezoelectric vibration devices

JP7856844B1JP 7856844 B1JP7856844 B1JP 7856844B1JP-7856844-B1

Abstract

[Problem] To enable welding joints while suppressing splash defects without using a sealing ring, and to achieve a low profile. [Solution] The package 2 comprises a bottomed cylindrical package body 10 having a bottom wall portion 10a and a peripheral wall portion 10b, and a lid 11 that is welded to the upper end opening edge of the peripheral wall portion to close the opening of the package body and form a sealing space C between itself and the package body, wherein a metal layer 30 is formed on the upper end opening edge of the peripheral wall portion, and the lid comprises a base material 40 which is a metal base material, and a plating layer 41 formed on the surface of the base material at least at the joint portion with the upper end opening edge of the peripheral wall portion, wherein the plating layer comprises a heat transfer plating layer 42 which has a lower melting point than the base material, and a molten plating layer 43 which has a lower melting point than the heat transfer plating layer and melts together with the metal layer. [Selection Diagram] Figure 3

Inventors

  • 柳 弘治
  • 溝延 大和

Assignees

  • エスアイアイ・クリスタルテクノロジー株式会社

Dates

Publication Date
20260511
Application Date
20251225

Claims (15)

  1. A package having an internal sealed space for housing a piezoelectric vibrator, A bottomed cylindrical package body having a bottom wall and a peripheral wall, and opening upwards, The package comprises a lid that is welded to the upper end opening edge of the peripheral wall portion to close the opening of the package body and to form the sealing space between itself and the package body, A metal layer is formed at the upper end opening edge of the peripheral wall portion. The aforementioned cover is The base material is a metal matrix, The substrate comprises a plating layer formed on the surface of the substrate, at least at the portion where it is joined to the upper end opening edge of the peripheral wall, The aforementioned plating layer is A heat transfer plating layer formed on the surface of the substrate, having a lower melting point than the substrate, A package characterized by having a molten plating layer formed on the surface of the heat transfer plating layer, having a lower melting point than the heat transfer plating layer, and melting together with the metal layer.
  2. In the package according to claim 1, The outer peripheral edge of the cover overlaps the upper end opening edge of the peripheral wall over its entire circumference. In a plan view of the package body, the overlapping region of the outer peripheral edge of the lid with respect to the upper opening edge of the peripheral wall is, A region occupying a certain distance radially inward from the outer end surface of the cover, which is a joint region welded to the peripheral wall via the metal layer, A package having a non-jointed region located radially inward from the jointed region and between the jointed region and the inner surface of the peripheral wall.
  3. In the package according to claim 2, The package is such that the cover is welded together such that the ratio of the non-jointed width along the radial direction of the non-jointed region to the wall width along the radial direction of the peripheral wall portion is greater than 11%.
  4. In the package described in claim 3, The package is such that the lid is welded together such that the ratio of the unjointed width to the wall width is less than 29%.
  5. In the package according to claim 2, The package is characterized in that the cover is welded together such that the non-jointed width along the radial direction of the non-jointed region is greater than the jointed width along the radial direction of the jointed region.
  6. In the package according to claim 3 or 4, The lid is welded to the package such that the total area of the lid is 65% or more and 85% or less of the outer surface area of the package body.
  7. In the package according to claim 2, The heat transfer plating layer is a copper layer. The aforementioned molten plating layer is a silver layer. The package is formed such that the plating layer is such that the ratio (T2/T1) of the thickness of the heat transfer plating layer, which is the copper layer, to the thickness T1 of the molten plating layer, which is the silver layer, is greater than 1 and less than or equal to 2.5.
  8. In the package according to claim 7, The aforementioned joining region is welded to the peripheral wall by melting the metal layer and the silver layer, in a package.
  9. In the package according to claim 1, A package in which the molten plating layer is formed to wrap around to the outer end surface of the lid and covers at least the heat transfer plating layer from the outside.
  10. In the package according to claim 2, On the upper surface of the lid in the joining region, an inclined surface is formed around its entire circumference, such that the thickness of the lid gradually decreases toward the radially outward direction. A package in which welding marks are formed on the aforementioned inclined surface.
  11. The package described in claim 1, A piezoelectric vibration device characterized by comprising: a piezoelectric vibrating piece housed within the sealing space of the package and mounted on the bottom wall via a conductive adhesive.
  12. In the piezoelectric vibration device according to claim 11, The aforementioned plating layer contains voids, A piezoelectric vibration device in which the voids are distributed in the plating layer such that their number decreases radially inward from the outer end surface of the lid.
  13. In the piezoelectric vibration device according to claim 11 or 12, The piezoelectric vibrating piece is A piezoelectric plate having a pair of vibrating arms extending along a first direction and arranged parallel to a second direction, and a base that integrally fixes the base ends of the vibrating arms, A piezoelectric vibration device comprising: an excitation electrode formed on the outer surface of the piezoelectric plate, which vibrates a pair of vibrating arms when a voltage is applied.
  14. In the piezoelectric vibration device according to claim 13, The piezoelectric vibrating piece is of the side-arm type, comprising a pair of support arms formed to extend outward from the base in the second direction and then in the first direction. A piezoelectric vibration device in which a pair of support arms are mounted on the bottom wall via the conductive adhesive.
  15. In the piezoelectric vibration device according to claim 11 or 12, The package body has an integrated circuit having multiple integrated circuit terminals, The aforementioned integrated circuit is mounted on the opposite side of the piezoelectric vibrator from the bottom wall portion of the package body, with the bottom wall portion in between, in a piezoelectric vibrator device.

Description

This invention relates to a package and a piezoelectric vibration device. Conventionally, piezoelectric vibration devices equipped with a piezoelectric vibrator made of quartz have been used in electronic devices such as mobile phones. A commonly known configuration of this type of piezoelectric vibration device includes, for example, a ceramic package having a recess with an open top, a piezoelectric vibrator housed within the ceramic package, and a metal lid joined to the opening of the ceramic package. The metal lid is superimposed on the frame-shaped upper opening edge of the ceramic package and sealed inside the ceramic package by welding it in place using resistance welding such as seam welding. When welding this type of metal lid, two methods are known: one in which the ceramic package and the metal lid are welded together via a sealing ring, and another in which the ceramic package and the metal lid are directly welded together without using a sealing ring (the so-called direct seam method). The seal ring is formed from a metal with a coefficient of thermal expansion similar to that of the ceramic material forming the ceramic package, and is joined to the upper opening edge of the ceramic package by baking or welding using brazing or soldering material. The metal lid is then welded to the seal ring by seam welding or the like. Thus, when welding a ceramic package and a metal lid together via a sealing ring, the sealing ring acts like a washer, making it possible to absorb in-plane displacement (variation) between the ceramic package and the metal lid. Furthermore, because the sealing ring provides stress relief, it can absorb high voltage (high power) during welding. As a result, it is possible to seal the package while suppressing warping of the metal lid. However, using a sealing ring increases the number of components and adds to the overall thickness of the device. Therefore, when aiming for miniaturization and a low profile, direct seam joining methods that do not utilize sealing rings are often employed. For example, Patent Document 1 describes a surface-mount type quartz crystal oscillator comprising a ceramic package, a quartz crystal diaphragm (piezoelectric vibrator) housed within the ceramic package, and a metal cover joined to the opening of the ceramic package. The metal lid is superimposed on the frame-shaped upper opening edge of the ceramic package and sealed inside the ceramic package by being directly welded to it by resistance welding such as seam welding. This metal lid comprises a plate-shaped metal base material, a copper layer formed over the entire lower surface of the metal base material, and a silver solder layer formed over the entire lower surface of the copper layer. Japanese Patent Publication No. 2003-158211 This figure shows a first embodiment of a piezoelectric vibration device according to the present invention, and is a perspective view of the external appearance of a piezoelectric vibrator.Figure 1 is an exploded perspective view of the piezoelectric vibrator shown.Figure 1 is a longitudinal cross-sectional view of the piezoelectric vibrator shown.Figure 3 is an enlarged cross-sectional view of the area near the welded joint between the peripheral wall of the package body and the lid.Figure 2 is a top view of the piezoelectric vibrator (including each electrode).This figure shows the heat accumulation range due to welding heat when seam welding a lid with high power.This diagram shows the heat accumulation range due to welding heat when seam welding a lid with low power.This figure shows a modified example of the first embodiment, and is an enlarged cross-sectional view of the vicinity of the welded joint between the peripheral wall of the package body and the lid.This figure shows a modified example of the first embodiment, illustrating the relationship between the area of the opening of the package body and the total area of the lid.This figure shows a modified example of the first embodiment, and is an enlarged cross-sectional view of the vicinity of the welded joint between the peripheral wall of the package body and the lid.This figure shows a second embodiment of the piezoelectric vibration device according to the invention, and is an external perspective view of the oscillator.Figure 11 is an exploded perspective view of the oscillator.Figure 11 is a longitudinal cross-sectional view of the oscillator along the line A-A.Figure 12 is a top view of the piezoelectric vibrator (including each electrode).This figure shows a modified example of a piezoelectric vibrator, and is a perspective view of an AT-cut vibrator. (First Embodiment) Hereinafter, a first embodiment of the package and piezoelectric vibration device according to the present invention will be described with reference to the drawings. In this embodiment, a piezoelectric vibrator is used as an example of a piezoelectric vibration device. As shown in Figures 1 to 3, the piezoelectric vibrator (piezo