Surface acoustic wave device and its manufacturing method

• US 5,252,882 A
• Filed: 06/27/1991
• Issued: 10/12/1993
• Est. Priority Date: 07/02/1990
• Status: Expired due to Term

• Current Assignee: Japan Radio Company Limited (Nisshinbo Holdings Incorporated)
• Original Assignee: Japan Radio Company Limited (Nisshinbo Holdings Incorporated)
• Inventors: Yatsuda, Hiromi
• Primary Examiner(s): Budd, Mark O.
• Assistant Examiner(s): Dougherty, Thomas M.
• Application Number:
  US07/721,823
• Time in Patent Office: 838 Days
• Field of Search: 310/313 R, 310/344, 310/348, 361/400, 361/403, 361/413, 439/68-73
• 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 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/4823 connecting the wire to a pin of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01058 : Cerium [Ce]
• CPC Class Codes: H01L 2924/0106 : Neodymium [Nd]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/30111 : matching
• CPC Class Codes: H03H 9/0547 : consisting of a vertical arrangement H03H9/0566 takes precedence
• 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: Y10T 29/42 : Piezoelectric device making
• CPC Class Codes: Y10T 29/49144 : by metal fusion

Abstract

A surface acoustic wave device and its manufacturing method. A surface acoustic wave device is used as filters for VHF and UHF range signals, or resonators for VHF and UHF range, by driving the surface of a surface acoustic wave element with applied signal to electrodes, transmitting a surface acoustic wave, and receiving the surface acoustic wave with other electrodes. In a configuration of a surface mount type surface acoustic wave device where a surface acoustic wave element is stored inside a package consisting of a base and a cover, pads are attached on a surface of the base and the surface acoustic wave element is fixed to the base by face down bonding.

Claims

1. A surface acoustic device comprising:

a surface acoustic wave element having an input electrode, an output electrode and an earth electrode, formed on one of the surfaces;

when a signal of a designated frequency range is applied between the input electrode and the earth electrode, surface acoustic wave is generated;

the surface acoustic wave is received by the output electrode and an electric signal is generated between the output electrode and the earth electrode;

a surface mount package having an input pad, an output pad and an earth pad, formed on the surface, the input pad, the output pad and the earth pad are placed on the surface of the surface mount package so that they face the input electrode, the output electrode and the earth electrode, respectively, and wherein the earth pad is formed on a predetermined area of the surface of the surface mount package except gap areas, along the border of the input pad and the output pad;

a connection means that electrically connects the input pad, the output pad and the earth pad with the input electrode, the output electrode, and the earth electrode, respectively, said connecting means comprising metal bumps provided on said input electrode, output electrode and earth electrode for electrically connecting said pads and electrodes when at least one of heat, pressure and supersonic wave is applied to said metal bumps; and

said surface mount package including positioning means for positioning the metal bumps formed on the input electrode, the output electrode and the earth electrode to the input pad, the output pad and the earth pad, respectively.

2. A surface acoustic wave device according to claim 1, wherein the surface acoustic wave device includes a designated number of reactance patterns that connects, with a designated resistance value, the earth pad with either the input pad or the output pad.

3. A surface acoustic wave device according to claim 2, wherein one of the reactance patterns is an inductance pattern that connects, with a designated inductance value, the earth pad with either the input pad or the output pad.

4. A surface acoustic wave device according to claim 2, wherein one of the reactance patterns is a capacitance pattern that connects, with a designated capacitance value, the earth pad with either the input pad or the output pad.

5. A surface acoustic wave device according to claim 2, wherein one of the reactance patterns is an inductance pattern that connects, with a designated inductance value, the earth pad with either the input pad or the output pad;

and the other one of the reactance patterns is a capacitance pattern that connects, with a designated capacitance value, the earth pad with either the input or the output pad.

6. A surface acoustic wave device comprising:

a surface acoustic wave element having an input electrode, output electrode and an earth electrode, formed on one of the surfaces;

when a signal of a designated frequency range is applied between the input electrode and the earth electrode, surface acoustic wave is generated;

the surface acoustic wave is received by the output electrode and an electric signal is generated between the output electrode and the earth electrode;

a surface mount package having an input pad, an output pad and an earth pad, formed on the surface, the input pad, the output pad and the earth pad are placed on the surface of the surface mount package so that they face the input electrode, the output electrode and the earth electrode, respectively, and wherein the surface acoustic wave device includes a high resistance pattern that is formed on the surface on the surface of the surface mount package, and connects, with high resistance, the earth pad with either the input pad or the output pad for avoiding discharge breakdown of the electrodes;

a connection means that electrically connects the input pad, the output pad and the earth pad with the input electrode, the output electrode, and the earth electrode, respectively, said connecting means comprising metal bumps provided on said input electrode, output electrode and earth electrode for electrically connecting said pads and electrodes when at least one of heat, pressure and supersonic wave is applied to said metal bumps; and

said surface mount package including positioning means for positioning the metal bumps formed on the input electrode, the output electrode and the earth electrode to the input pad, the output pad and the earth pad, respectively.

7. A surface acoustic wave device according to claim 6, wherein the electrical conductivity of a material forming the high resistance pattern is lower than the electrical conductivity of materials that form the input pad or the output pad.

8. A surface acoustic wave device comprising:

(a) a surface acoustic wave element having an input electrode, an output electrode and an earth electrode, formed on one of the surfaces;

when a signal of a designated frequency range is applied between the input electrode and the earth electrode, surface acoustic wave is generated;

the surface acoustic wave is received by the output electrode and an electric signal is generated between the output electrode and the earth electrode;

(b) a surface mount package having an input pad, and output pad, and an earth pad, formed on the surface;

the input pad, the output pad and the earth pad are placed on the surface of the surface mount package so that they face the input electrode, the output electrode and the earth electrode, respectively;

(c) a connection means that electrically connects the input pad, the output pad and the earth pad with the input electrode, the output electrode and the earth electrode, respectively; and

(d) a high resistance pattern that is formed on the surface of the surface mount package, and connects, with high resistance, the earth pad with either the input pad or the output pad.

9. A surface acoustic wave device according to claim 8, wherein the electrical conductivity of a material forming the high resistance pattern is lower than the electrical conductivity of materials that form the input pad or the output pad.

10. A surface acoustic wave device comprising:

(a) a surface acoustic wave element having an input electrode, an output electrode and an earth electrode, formed on one of the surfaces;

when a signal of a designated frequency range is applied between the input electrode and the earth electrode, surface acoustic wave is generated;

the surface acoustic wave is received by the output electrode and an electric signal is generated between the output electrode and the earth electrode;

(b) a surface mount package having an input pad, an output pad and an earth pad, formed on the surface;

the input pad, the output pad and the earth pad are placed on the surface mount package so that they face the input electrode, the output electrode and the earth electrode, respectively;

(c) a connection means that electrically connects the input pad, the output pad and the earth pad with the input electrode, the output electrode and the earth electrode, respectively; and

(d) a designated number of reactance patterns that connects, with a designated reactance value, the earth pad with the either the input pad or the output pad.

11. A surface acoustic wave device according to claim 10, wherein one of the reactance patterns is an inductance pattern that connects, with a designated inductance value, the earth pad with either the input pad or the output pad.

12. A surface acoustic wave device according to claim 10, wherein one of the reactance patterns is a capacitance pattern that connects, with a designated capacitance value, the earth pad with either the input pad or the output pad.

13. A surface acoustic wave device according to claim 10, wherein one of the reactance patterns is an inductance pattern that connects, with a designated inductance value, the earth pad with either the input pad or the output pad;

and the other one of the reactance patterns is a capacitance pattern that connects, with a designated capacitance value, the earth pad with either the input pad or the output pad.

14. A surface wave acoustic device comprising:

(a) a surface acoustic wave element having an input electrode, an output electrode and an earth electrode, formed on one of the surfaces;

when a signal of a designated frequency range is applied between the input electrode and the earth electrode, surface acoustic wave is generated;

the surface acoustic wave is received by the output electrode and an electric signal is generated between the output electrode and the earth electrode;

(b) a surface mount package having an input pad, an output pad and an earth pad, formed on the surface;

the input pad, the output pad and the earth pad are placed on the surface of the surface mount package so that they face the input electrode, the output electrode and the earth electrode, respectively;

(c) a connection means that electrically connects the input pad, the output pad and the earth pad with the input electrode, the output electrode, and the earth electrode, respectively; and

(d) a high resistance pattern that is formed on the surface of the surface mount package and connects, with high resistance, the earth pad with either the input pad or the output pad, for avoiding discharge breakdown of the electrodes.

15. A surface acoustic device according to claim 14 wherein the electrical conductivity of a material formed in the high resistance pattern is lower than the electrical conductivity of materials that form the input pad or the output pad.

16. A surface acoustic wave device according to claim 14, wherein the earth pad is formed on a predetermined area of the surface mount package except gap areas, along the border of the input pad and the output pad.