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CN-115395909-B - Elastic wave device and module comprising same

CN115395909BCN 115395909 BCN115395909 BCN 115395909BCN-115395909-B

Abstract

An elastic wave device includes a wiring substrate, a device chip electrically connected to the wiring substrate, and a sealing portion sealing the device chip with the wiring substrate. The device chip comprises a resonator for exciting the surface acoustic wave, a first metal layer electrically connected with the resonator, a first insulating layer formed on part of the surface of the first metal layer and the resonator, and a second metal layer which can be used as a bump pad and is formed on the area of the surface of the first metal layer which is not covered by the first insulating layer and the area of the first insulating layer which is covered by the first metal layer. Thus, an elastic wave device capable of suppressing corrosion of wiring and resonators in a device chip can be provided.

Inventors

  • KUWABARA HIDESHI

Assignees

  • 三安日本科技株式会社
  • 三安日本科技株式会社

Dates

Publication Date
20260421
Application Date
20210913
Priority Date
20210524

Claims (12)

  1. 1. An elastic wave device comprising: a wiring substrate; a device chip electrically connected to the wiring substrate; a sealing portion for sealing the device chip with the wiring substrate, The method is characterized in that: The device chip comprises a resonator for exciting surface acoustic waves, a first metal layer electrically connected with the resonator, a first insulating layer formed on a part of the surface of the first metal layer and the resonator, and a second metal layer capable of being used as a bump pad and formed on a region of the surface of the first metal layer which is not covered by the first insulating layer and a region of the first insulating layer which is covered by the first metal layer, and further comprises a second insulating layer formed on a part of the surfaces of the first insulating layer and the second metal layer, wherein the edge of the second metal layer is located in the inner region of the first metal layer when seen from the direction perpendicular to the wiring substrate, and the edge of the second insulating layer is located in the inner region of the second metal layer.
  2. 2. The elastic wave device according to claim 1, wherein: the first metal layer is not directly connected to the second insulating layer.
  3. 3. The elastic wave device according to claim 1, wherein: The second metal layer is directly connected with the first metal layer, the first insulating layer and the second insulating layer.
  4. 4. The elastic wave device according to claim 1, wherein: The first insulating layer is directly connected with the first metal layer, the second metal layer and the second insulating layer.
  5. 5. The elastic wave device according to claim 1, wherein: the first insulating layer has a coefficient of thermal expansion that is less than a coefficient of thermal expansion of the second insulating layer.
  6. 6. The elastic wave device according to claim 1, wherein: the width of the second metal layer is smaller than the width of the first metal layer.
  7. 7. The elastic wave device according to claim 1, wherein: the device chip is formed by bonding a piezoelectric substrate and a supporting substrate, wherein the supporting substrate is made of sapphire, silicon, alumina, spinel, crystal or glass.
  8. 8. The elastic wave device according to claim 1, wherein: The elastic wave device further includes a second device chip provided with a band-pass filter formed of a plurality of surface acoustic wave resonators.
  9. 9. The elastic wave device according to claim 1, wherein: The elastic wave device further includes a second device chip provided with a band-pass filter formed of a plurality of acoustic thin film resonators.
  10. 10. An elastic wave device comprising: a wiring substrate; a device chip electrically connected to the wiring substrate; a sealing portion for sealing the device chip with the wiring substrate, The method is characterized in that: The device chip includes a resonator that excites a surface acoustic wave, a first metal layer that electrically connects a part of a surface of the first metal layer and the resonator, a first insulating layer that is formed on the first metal layer, a second metal layer that is formed on a region of the first insulating layer that is not covered by the first insulating layer and a region of the first insulating layer that covers the first metal layer surface, a third metal layer that is formed on a part of a surface of the second metal layer and can serve as a bump pad, and a second insulating layer that is formed on a side surface of the first insulating layer, a side surface of the second metal layer, a side surface of the third metal layer, and a part of a surface of the third metal layer, an edge of the second insulating layer being in the third metal layer region, an edge of the third metal layer being in the second metal layer region, and an edge of the second metal layer being in the first metal layer region, as viewed from a direction perpendicular to the wiring substrate.
  11. 11. The elastic wave device according to claim 10, wherein: the width of the second metal layer is smaller than that of the first metal layer, and the width of the third metal layer is smaller than that of the second metal layer.
  12. 12. A module comprising the elastic wave device according to any one of claims 1 to 11.

Description

Elastic wave device and module comprising same Technical Field The present disclosure relates to an elastic wave device and a module including the same. Background Patent document 1 (japanese patent application laid-open No. 2017-157922) exemplifies an elastic wave device. The elastic wave device radiates heat through heat radiation paths such as through holes. However, in the elastic wave device illustrated in patent document 1, the wiring of the device chip and the resonator are exposed inside the sealing portion. Therefore, the wiring and the resonator of the device chip may be corroded. Disclosure of Invention In view of the above, an object of the present disclosure is to provide an elastic wave device capable of suppressing corrosion of wiring and resonators in a device chip, and an elastic wave device module including the elastic wave device. The elastic wave device comprises a wiring substrate, a device chip electrically connected with the wiring substrate, and a sealing part sealing the device chip with the wiring substrate, wherein the device chip comprises a resonator for exciting an elastic surface wave, a first metal layer electrically connected with the resonator, a first insulating layer formed on part of the surface of the first metal layer and the resonator, and a second metal layer, and the second metal layer can be used as a bump pad and is formed on a region, which is not covered by the first insulating layer, of the surface of the first metal layer and a region, which is covered by the first metal layer, of the first insulating layer. In one aspect of the present disclosure, the elastic wave device further includes a second insulating layer formed on a part of surfaces of the first insulating layer and the second metal layer. In one aspect of the disclosure, the first metal layer is not directly connected to the second insulating layer. In one aspect of the disclosure, the second metal layer is directly connected to the first metal layer, the first insulating layer, and the second insulating layer. In one aspect of the disclosure, the first insulating layer directly connects the first metal layer, the second metal layer, and the second insulating layer. In one aspect of the present disclosure, the first insulating layer has a coefficient of thermal expansion that is less than a coefficient of thermal expansion of the second insulating layer. In one aspect of the present disclosure, the second metal layer has a width that is less than a width of the first metal layer. In one embodiment of the present disclosure, the device chip is formed by bonding a piezoelectric substrate to a support substrate made of sapphire, silicon, alumina, spinel, crystal, or glass. In one embodiment of the present disclosure, the second device chip further includes a band-pass filter formed of a plurality of surface acoustic wave resonators. In one embodiment of the present disclosure, the second device chip further includes a band-pass filter formed of a plurality of acoustic thin film resonators. The elastic wave device comprises a wiring substrate, a device chip electrically connected with the wiring substrate, a sealing part sealing the device chip with the wiring substrate, wherein the device chip comprises a resonator for exciting an elastic surface wave, a first metal layer electrically connected with the resonator, a first insulating layer formed on part of the surface of the first metal layer and the resonator, a second metal layer formed on the area which is not covered by the first insulating layer in the surface of the first metal layer and the area which is covered by the first metal layer in the first insulating layer, a third metal layer formed on part of the surface of the second metal layer and capable of being used as a bump bonding pad, and a second insulating layer formed on part of the surface of the first insulating layer, the side surface of the second metal layer and the side surface of the third metal layer. In one aspect of the disclosure, the width of the second metal layer is smaller than the width of the first metal layer, and the width of the third metal layer is smaller than the width of the second metal layer. One aspect of the present disclosure includes a module of the elastic wave device. The invention has the beneficial effect that according to the disclosure, corrosion of wiring and resonators in a device chip is inhibited. Drawings Fig. 1 is a cross-sectional view of an elastic wave device in a first embodiment. Fig. 2 is a top view of a device chip of the elastic wave device in the first embodiment. Fig. 3 is a partial cross-sectional view of the device chip in the first embodiment. Fig. 4 is a partial cross-sectional view of the device chip in the first embodiment. Fig. 5 is a partial top view of the device chip in the first embodiment. Fig. 6 is a schematic view of an elastic wave assembly of the device chip in the first embodiment. Fig. 7 is a cross-sectional view of an