Elastic wave device, communication module apparatus, and method for manufacturing elastic wave device

Patent metadata

Field	Value
Publication number	US-10164603-B2
Application number	US-201715687587-A
Country	US
Kind code	B2
Filing date	Aug 28, 2017
Priority date	Mar 27, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

An elastic wave device includes an elastic wave element that includes first support layers provided on a piezoelectric substrate, a second support layer provided on the piezoelectric substrate so as to surround the first support layers when viewed in a plan view, and a cover member provided on the first support layers and the second support layer, a mounting substrate on which the elastic wave element is mounted, and a mold resin provided on the mounting substrate and sealing the elastic wave element. A thickness of each of the first support layers is less than a thickness of the second support layer. The cover member convexly curves towards the piezoelectric substrate so as to be spaced away from the mounting substrate. A space between the mounting substrate and the cover member is filled with the mold resin.

First claim

What is claimed is:

1. An elastic wave device comprising:
an elastic wave element including a piezoelectric substrate that includes a pair of main surfaces opposing each other, an excitation electrode provided on one main surface of the piezoelectric substrate, at least one first support layer provided on the one main surface of the piezoelectric substrate, a second support layer provided on the one main surface of the piezoelectric substrate so as to surround the excitation electrode and the at least one first support layer when viewed in a plan view, and a cover member provided on the first and second support layers and sealing the excitation electrode together with the second support layer and the piezoelectric substrate;
a mounting substrate on which the elastic wave element is mounted; and
a mold resin provided on the mounting substrate and sealing the elastic wave element; wherein
a thickness of the at least one first support layer is less than a thickness of the second support layer;
the cover member convexly curves towards the piezoelectric substrate so as to be spaced away from the mounting substrate; and
a space between the mounting substrate and the cover member is filled with the mold resin.

2. The elastic wave device according to claim 1 , wherein
the at least one first support layer has a width direction in a direction crossing the at least one first support layer;
the second support layer has a width direction in a direction crossing the second support layer; and
a width of the at least one first support layer is less than a width of the second support layer.

3. The elastic wave device according to claim 2 , wherein
a plurality of the first support layers are provided;
a width of at least one first support layer of the plurality of first support layers is less than widths of others of the plurality of first support layers; and
a thickness of at least one first support layer of the plurality of first support layers is less than thicknesses of others of the plurality of first support layers.

4. The elastic wave device according to claim 1 , wherein, when the elastic wave device is viewed in the plan view, the at least one first support layer makes contact with the second support layer at both ends of the at least one first support layer.

5. The elastic wave device according to claim 1 , wherein the at least one first support layer includes a first end portion and a second end portion, the first end portion of the at least one first support layer makes contact with the second support layer, and a shape of the second end portion of the at least one first support layer is larger than a shape of a portion other than the second end portion, when the elastic wave device is viewed in the plan view.

6. The elastic wave device according to claim 1 , wherein
the at least one first support layer has a width direction in a direction crossing the at least one first support layer;
the second support layer has a width direction in a direction crossing the second support layer; and
a width of the at least one first support layer is the same or substantially the same as a width of the second support layer.

7. A communication module apparatus comprising:
a front-end portion including the elastic wave device according to claim 1 ; and
an active element connected to the front-end portion.

8. The communication module apparatus according to claim 7 , wherein
the at least one first support layer has a width direction in a direction crossing the at least one first support layer;
the second support layer has a width direction in a direction crossing the second support layer; and
a width of the at least one first support layer is less than a width of the second support layer.

9. The communication module apparatus according to claim 8 , wherein
a plurality of the first support layers are provided;
a width of at least one first support layer of the plurality of first support layers is less than widths of others of the plurality of first support layers; and
a thickness of at least one first support layer of the plurality of first support layers is less than thicknesses of others of the plurality of first support layers.

10. The communication module apparatus according to claim 7 , wherein, when the elastic wave device is viewed in the plan view, the at least one first support layer makes contact with the second support layer at both ends of the at least one first support layer.

11. The communication module apparatus according to claim 7 , wherein the at least one first support layer includes a first end portion and a second end portion, the first end portion of the at least one first support layer makes contact with the second support layer, and a shape of the second end portion of the at least one first support layer is larger than a shape of a portion other than the second end portion, when the elastic wave device is viewed in the plan view.

12. The communication module apparatus according to claim 7 , wherein
the at least one first support layer has a width direction in a direction crossing the at least one first support layer;
the second support layer has a width direction in a direction crossing the second support layer; and
a width of the at least one first support layer is the same or substantially the same as a width of the second support layer.

13. A method for manufacturing an elastic wave device comprising:
a step of manufacturing an elastic wave element including a piezoelectric substrate that includes a pair of main surfaces opposing each other, an excitation electrode provided on one main surface of the piezoelectric substrate, at least one first support layer provided on the one main surface of the piezoelectric substrate, a second support layer provided on the one main surface of the piezoelectric substrate so as to surround the excitation electrode and the at least one first support layer when viewed in a plan view, and a cover member provided on the first and second support layers and sealing the excitation electrode together with the second support layer and the piezoelectric substrate;
a step of mounting the elastic wave element on a mounting substrate; and
a step of providing a mold resin on the mounting substrate and sealing the elastic wave element; wherein
in the step of manufacturing the elastic wave element, the first and second support layers are provided such that a thickness of the at least one first support layer is less than a thickness of the second support layer, and the cover member is convexly curved towards the piezoelectric substrate so as to be spaced away from the mounting substrate; and
in the step of sealing the elastic wave element, the mold resin is provided so as to fill a space between the mounting substrate and the cover member with the mold resin.

14. The method for manufacturing the elastic wave device according to claim 13 , wherein a plurality of the first support layers are provided, and the plurality of first support layers are provided such that a width of at least one first support layer of the plurality of first support layers is smaller than widths of other first support layers.

15. The method for manufacturing the elastic wave device according to claim 14 , wherein a thickness of at least one first support layer of the plurality of first support layers is less than thicknesses of others of the plurality of first support layers.

16. The method for manufacturing the elastic wave device according to claim 13 , wherein
the at least one first support layer has a width direction in a direction crossing the at least one fi

Assignees

• Murata Manufacturing Co

Inventors

• Sekiya Daisuke
• Kikuchi Taku
• Hirano Yasuhiko
• Tanaka Hiroshi

Classifications

• H10W72/012

  of bump connectors, dummy bumps or thermal bumps · CPC title

• H10W74/40

  characterised by their materials · CPC title

• H10W74/10

  characterised by their shape or disposition · CPC title

• H03H9/1014 Primary

  the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device · CPC title

• H03H9/059

  consisting of mounting pads or bumps · CPC title