Surface acoustic wave device and method of manufacturing the device

• US 6,914,367 B2
• Filed: 07/06/2001
• Issued: 07/05/2005
• Est. Priority Date: 07/06/2000
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Furukawa, Osamu
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US10/312,863
• Publication Number:
  US 20030112986A1
• Time in Patent Office: 1,460 Days
• Field of Search: 310/313.R, 310/340, 310/348
• US Class Current: 310/340
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H03H 3/08 for the manufacture of resonators or networks using surface acoustic waves
• CPC Class Codes: H03H 9/059 consisting of mounting pads or bumps
• CPC Class Codes: H03H 9/1078 the enclosure being defined by a foil covering the non-active sides of the SAW device
• CPC Class Codes: H03H 9/1085 the enclosure being defined by a non-uniform sealing mass covering the non-active sides of the BAW device
• CPC Class Codes: H03H 9/25 Constructional features of resonators using surface acoustic waves devices for manipulating acoustic surface waves in general G10K11/36

Abstract

A surface acoustic wave device used in, for example, a mobile communications field as a filter or duplexer and the like to handle high frequencies of about several GHz is fabricated by flip-chip-connecting a surface of a piezoelectric substrate to a base board facing thereto, emitting particulate first sealing material from above a back face of the piezoelectric substrate to apply the first sealing material to the back face of the piezoelectric substrate and hang the first sealing material from edges of the piezoelectric substrate to the base board to form bridging, and forming second sealing material on the first sealing material. These operations provide a manufacturing method of a small-sized surface-mounting surface acoustic wave device appropriate for flip-chip connection.

Claims

1. A surface acoustic wave device comprising:

a surface acoustic wave element with an interdigital transducer formed on a surface of a piezoelectric substrate;

a base board to which the surface acoustic wave element is flip-chip-connected;

a base layer applied to a back face of the piezoelectric substrate and hanging from edges of the piezoelectric substrate to the base board to form bridging; and

a clad layer applied to the base layer,

wherein an edge of the base layer is exposed after dicing.

2. The surface acoustic wave device of claim 1, wherein the clad layer is a layer denser than the base layer.

3. The surface acoustic wave device of claim 1, wherein the clad layer is a metal layer.

4. The surface acoustic wave device of claim 1, wherein the base layer is a metal layer.

5. The surface acoustic wave device of claim 1, wherein the base layer is an insulating layer.

6. The surface acoustic wave device of claim 1, wherein a distance between the surface acoustic wave element and the base board is 100 μ

m or smaller.