Surface acoustic wave device and boundary acoustic wave device

A surface acoustic wave and boundary wave technology, applied in impedance networks, electrical components, electrical solid devices, etc., can solve problems such as deterioration of isolation characteristics

Active Publication Date: 2009-02-04
MURATA MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If capacitive coupling increases, it is related to deterioration of isolation characteristics and VSWR

Method used

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  • Surface acoustic wave device and boundary acoustic wave device
  • Surface acoustic wave device and boundary acoustic wave device
  • Surface acoustic wave device and boundary acoustic wave device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] Refer to Figure 1 to Figure 6 , the surface acoustic wave device 10 of the first embodiment will be described.

[0062] Such as figure 1 As shown in the cross-sectional view of the surface acoustic wave device 10 , the conductive pattern 20 including the IDT 22 and the pad 23 is formed on the upper surface 14 which is one of the main surfaces of the piezoelectric substrate 12 . On the upper surface 14 , gaps are provided across the supporting layer 30 , and the cover 32 is arranged to face each other, thereby forming the vibration space 16 around the IDT 22 . That is, the IDT 22 is arranged inside the support layer 30 , and the surface acoustic wave freely propagates in the portion of the piezoelectric substrate 12 adjacent to the vibration space 16 . The support layer 30 is formed on the inner side of the peripheral portion 15 of the upper surface 14 of the piezoelectric substrate 12 .

[0063] In addition, the reinforcing resin 36 covers the peripheral portion 1...

Embodiment 2

[0087] The surface acoustic wave device of the second embodiment has substantially the same configuration as that of the first embodiment. However, the only difference from Embodiment 1 is that a part of the wiring (for example, wiring More than half of the length) is not formed on the upper surface 33 of the cover 32, but is formed on the lower surface 34 of the cover 32. In Example 2, the conductive pattern corresponding to the conductive pattern 25 v is formed in advance on the lower surface 34 of the cover 32 , and the cover 32 and the piezoelectric substrate 12 are made to face each other, and are coupled by the supporting layer 30 . In Example 2, the capacitive coupling between wirings is also reduced, and the effect of improving the isolation characteristic can be obtained.

Embodiment 3

[0088] Referring to FIG. 7, a surface acoustic wave device of Example 3 will be described. FIG. 7 is a structural view of the conductive pattern on the upper surface 14 of the piezoelectric substrate 12, corresponding to FIG. 2 of the first embodiment.

[0089] The surface acoustic wave device of the third embodiment has substantially the same configuration as that of the first embodiment, and the reception-side surface acoustic wave filter 50 and the transmission-side surface acoustic wave filter 60 are arranged on the piezoelectric substrate 12 .

[0090] The surface acoustic wave device of Embodiment 3 is different from Embodiment 1 in that the receiving-side SAW filter 50 and the transmitting-side SAW filter 60 are connected to the common antenna pad 41, and the wiring of the transmitting-side SAW filter 60 A part is set on the cover 32.

[0091] That is, the wires connecting the resonators 210 and 220 are separated, and the resonators 210 and 220 are connected to the re...

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PUM

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Abstract

A surface acoustic wave device and a boundary acoustic wave device capable of reducing capacitive coupling are provided. A piezoelectric substrate (12) is joined to a cover (32) with a support layer 30 therebetween and with a spacing kept therebetween. A transmission surface acoustic wave filter and a reception surface acoustic wave filter are formed on a major surface (14) of the piezoelectric substrate (12) adjacent to the cover (32) and inside the support layer (30). External electrodes (28) are provided on the side of the cover (32) opposite that facing the piezoelectric substrate (12).; The external electrodes (28) include an antenna terminal electrically connected to the transmission surface acoustic wave filter and the reception surface acoustic wave filter, a transmission input terminal electrically connected to the transmission surface acoustic wave filter, and a reception output terminal electrically connected to the reception surface acoustic wave filter. Part of an interconnection line that electrically connects the reception surface acoustic wave filter to the antenna terminal is disposed on the cover (32).

Description

technical field [0001] The present invention relates to surface acoustic wave devices and acoustic boundary wave devices. Background technique [0002] In recent years, for surface acoustic wave devices such as surface acoustic wave filters and boundary acoustic wave devices such as boundary acoustic wave filters, development of wafer-level chip-scale packages (WLCSP) in which packages are miniaturized to the size of an element chip is underway. [0003] For example in Figure 13 In the shown surface acoustic wave device, a piezoelectric substrate 1 on which a conductive pattern including an IDT (comb electrode) 2, a reflector 3, and a bonding pad 4 is formed, and a resin substrate 8 on which an external electrode 8 is provided are arranged oppositely. The resins 6a and 6b are bonded and sealed to electrically connect the pad 4 and the external electrode 8 (for example, refer to Patent Document 1). [0004] Patent Document 1: JP-A-2003-37471 [0005] When a structure in wh...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H03H9/72H03H9/25
CPCH03H9/1092H03H9/0576H03H9/725H01L2224/11H01L2224/05569H01L2224/05024H01L2224/05085H01L2224/05008H01L2224/05022H01L2224/05026H01L2224/0557H01L2224/05001H01L2224/05144H01L2224/05166H01L2924/00014H01L2224/05571H01L2224/06135H01L2224/05599
Inventor 田中伸拓
Owner MURATA MFG CO LTD
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