Surface-acoustic-wave device

• US 6,150,748 A
• Filed: 02/01/1999
• Issued: 11/21/2000
• Est. Priority Date: 02/20/1998
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Fukiharu, Eiichi
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US09/241,015
• Time in Patent Office: 659 Days
• Field of Search: 310/313 R, 310/340, 310/344, 310/348
• US Class Current: 310/313.00R
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H03H 9/059 consisting of mounting pads or bumps
• CPC Class Codes: H03H 9/1071 the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the SAW device
• CPC Class Codes: H03H 9/1078 the enclosure being defined by a foil covering the non-active sides of the SAW device

Abstract

The surface-acoustic-wave device has surface-acoustic-wave element 1 provided with interdigital electrodes 2, shut-off member 32 and ground patterns 35-1, 35-2. Interdigital electrodes 2 are formed on a first surface of surface-acoustic-wave element 1 and covered with protective film 33. Surface-acoustic-wave element 1 is mechanically supported above mounting substrate 36. Shut-off member 32 serves to shut off surface-acoustic-wave element 1 electrically and airtightly from an ambience. The ground patterns 35-1, 35-2, grounded electrically, serve to discharge an electric charge. Ground patterns 35-1, 35-2 contact a surface of mounting substrate 36. Shut-off member 32 covers surface-acoustic-wave element 1 and also is connected with ground patterns 35-1, 35-2 that are in contact with the surface of mounting substrate 36.

Claims

1. A surface-acoustic-wave device having a surface-acoustic-wave element with interdigital electrodes formed on a first surface, said surface-acoustic-wave element being mounted on a mounting substrate, said surface-acoustic-wave device including

a conductive film for electrically and airtightly shielding off said surface-acoustic-wave element from an external noise field and ambience, and

grounding means electrically grounded for discharging an electric charge, said grounding means having sections provided on a surface of said mounting substrate, said conductive film covering said surface-acoustic-wave element and being in contact with a second surface opposite to said first surface and side surfaces of said surface-acoustic-wave element, said conductive film having end-portions that are electrically and mechanically attached to said sections of said grounding means provided on said mounting substrate.

2. A device as claimed in claim 1, wherein said conductive film has a thermocrimping property and is made to contact with said second surface and side surfaces of said surface-acoustic-wave element using heat and pressure.

3. A device as claimed in claim 1, wherein said conductive film and each of said sections of said grounding means are connected with each other through a conductive resin member.

4. A device as claimed in claim 1, wherein said conductive film and said sections of said grounding means are connected with each other through a conductive adhesive material.

5. A device as claimed in claim 1, wherein said end portions of said conductive film are bent inward to be connected with sections of said grounding means.

6. A device as claimed in claim 1, wherein said end portions of said conductive film are bent outward to be connected with said sections of said grounding means.

7. A device as claimed in claim 1, wherein said interdigital electrodes are covered with a protective layer to protect the interdigital electrodes from corrosion.

8. A surface-acoustic-wave device having a surface-acoustic-wave element with interdigital electrodes formed on a first surface, said surface-acoustic-wave element being mounted on a mounting substrate, said surface-acoustic-wave device including

a conductive film for electrically and airtightly shielding off said surface-acoustic-wave element from an external noise field and ambience, and

grounding means electrically grounded for discharging an electric charge, said grounding means having sections provided on a surface of said mounting substrate,

said mounting substrate is a multiple-layer substrate having a first layer provided with a through-hole, said surface-acoustic-wave element is embedded in the through-hole with a second surface thereof arranged to be flush with a surface of said multiple-layer substrate, said second surface being a surface opposite to said first surface, and said conductive film contacts said section of said grounding means in such a manner that said conductive film contacts both said second surface of said surface-acoustic-wave element and said sections provided on said surface of said multiple-layer substrate.