Bulk acoustic wave filter

• US 6,466,105 B1
• Filed: 07/05/2000
• Issued: 10/15/2002
• Est. Priority Date: 07/07/1999
• Status: Expired due to Term

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.), US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Leyten, Lukas, Klee, Mareike, Lobl, Hans-Peter
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): TAKAOKA, DEAN O
• Application Number:
  US09/610,595
• Time in Patent Office: 832 Days
• Field of Search: 333/187, 333/186, 333/189, 333/191, 310/364, 310/335, 310/348, 310/322
• US Class Current: 333/187
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/02149 of ageing changes of characteristics, e.g. electro-acousto-migration
• CPC Class Codes: H03H 9/175 Acoustic mirrors
• CPC Class Codes: H03H 9/581 comprising ceramic piezoelectric layers
• CPC Class Codes: H03H 9/589 Acoustic mirrors

Abstract

The invention describes a filter arrangement as well as an electronic component, each with a bulk acoustic wave resonator unit which is present on a carrier substrate (1). A reflection element (2) is provided between the carrier substrate (1) and the bulk acoustic wave resonator unit for the purpose of acoustic insulation of the generated oscillations. This reflection element (2) may consist either of several layers of alternately high and low impedance or, if the acoustically reflecting substance has a sufficiently low impedance, of a single layer. In addition, a mobile telephone device, a transmitter, a receiver, and a wireless data transmission system as well as a method of manufacturing an electronic component are described.

Claims

1. A filter arrangement with a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate and the resonator unit, characterized in that the reflection element (2) consists of a unitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerogel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.

7. A filter arrangement as claimed in claim 1, characterized in that a further reflection element (6) is arranged on the resonator unit.

8. A filter arrangement as claimed in claim 1, characterized in that a protective layer (7) of an organic and/or inorganic material is provided over the filter arrangement.

9. A filter arrangement as claimed in claim 1, characterized in that the carrier substrate (1) comprises a ceramic material, a ceramic material with a glass planarizing layer, a glass-ceramic material, a glass material, silicon, GaAs, or sapphire.

10. A filter arrangement as claimed in claim 1, characterized in that the resonator unit comprises a piezoelectric layer (4) of PbZr_0.15Ti_0.85O₃ doped with 2% lanthanum.

11. A filter arrangement as claimed in claim 1, characterized in that a layer of SiO₂ is present above and below a reflection element (2, 6).

12. A filter arrangement as claimed in claim 1, characterized in that an adhesive layer is arranged between the carrier substrate (1) and the reflection element (2).

2. A mobile telephone device provided with a filtier arrangement having a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate (1) and the resonator unit, characterized in that the reflection element (2) consists of a unitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerogel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.

3. A transmitter provided with a filter arrangement having a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate (1) and the resonator unit, characterized in that the reflection element (2) consists of a uinitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerbgel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.

4. A receiver provided with a filter arrangement having a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate (1) and the resonator unit, characterized in that the reflection element (2) consists of a unitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerogel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.

5. A wireless data transmission system provided with a filter arrangement having a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate (1) and the resonator unit, characterized in that the reflection element (2) consists of a unitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerogel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.

6. An electronic component with a carrier substrate (1), a resonator unit, and a reflection element (2) between the carrier substrate (1) and the resonator unit, characterized in that the reflection element (2) consists of a unitary layer formed of an acoustically reflecting substance selected from the group consisting of silica aerogel or organic aerogel, xerogel, glass foam, foam-type adhesive, foamed synthetic resin and a low density synthetic resin.