JP2002271169A - Surface acoustic wave device and communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device the signal propagation characteristics of which are improved, especially at a frequency of 1 GHz or higher. SOLUTION: A plurality of surface acoustic wave device elements 3 are mounted facedown in a package 1. External connection terminals 2a and 2b for input and external connection terminals 2c and 2d for output, connected with respective surface acoustic device elements 3, are provided at the bottom face 1a of the package 1, and external connection terminals 2e and 2f for ground are provided, respectively, between the external connection terminals 2a and 2b for the input and the external connection terminals 2c and 2d for the output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a metal bump on an element electrode formed on a piezoelectric substrate of a surface acoustic wave element and forming a metal bump on an internal electrode formed in an electronic component package made of ceramic or the like. The present invention relates to a surface acoustic wave device using a flip-chip method for connecting the above-mentioned element electrodes through a device, and a communication device having the same.

[0002]

2. Description of the Related Art In recent years, a flip chip method has been studied in order to reduce the size of a surface acoustic wave device used for a communication device such as a mobile phone. The flip-chip method uses metal bumps formed on the electrode pads of the piezoelectric substrate of the surface acoustic wave element to ensure electrical continuity between the surface acoustic wave element and the electronic component package. The surface acoustic wave element is fixed to the electronic component package.

Japanese Patent Application Laid-Open No. H11-122072 discloses a multi-chip structure in which a plurality of surface acoustic wave devices are mounted on one electronic component package by using the flip-chip method. No. The above publication states that the multichip structure can achieve high efficiency and miniaturization.

In an electronic device having a multi-chip structure,
Multifunctionalization such as multi-filtering and balance filtering is relatively easy. In the case of such a multifunctional electronic device, there are a plurality of external connection terminals for input and output. Therefore, the number of external connection terminals formed on the outer shape of the electronic device increases. On the other hand, since the electronic device itself has been downsized by adopting the flip-chip method, the external connection terminals have a small interval between each other, that is, a narrow pitch.

[0005]

However, in the conventional technique described above, there is a problem that a problem occurs due to a narrow pitch of each external connection terminal and an increase in the number of each external connection terminal for signal.

For example, if the input external connection terminal and the output external connection terminal are adjacent to each other at a narrow pitch, the bridging capacitance increases between the input external connection terminal and the output external connection terminal. The external connection terminal and the output external connection terminal
Direct coupling due to increased bridging capacity. For this reason, filter characteristics (signal transmission characteristics such as signal transmission characteristics within a pass band and signal reduction characteristics outside a pass band) such as deterioration of attenuation are caused.

In the case of an electronic device such as a multi-filter having a plurality of surface acoustic wave elements, if each signal external connection terminal of each surface acoustic wave element such as a different filter is adjacent to each other at a narrow pitch, they are The bridging capacitance between each external connection terminal increases. For this reason, crosstalk increases between signals passing through each external connection terminal, the attenuation outside the pass band is deteriorated, and an unnecessary response occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems that occur in each external connection terminal having a reduced pitch.

[0009]

In order to solve the above-mentioned problems, the surface acoustic wave device of the present invention comprises a surface acoustic wave element which converts an input signal by a surface acoustic wave and outputs the converted signal. An external connection terminal for signal, which is mounted face down by a metal bump on the first surface of the substrate and electrically connects the surface acoustic wave element and an external circuit, is opposite to the first surface of the holding substrate. An external connection terminal for grounding is formed along a peripheral portion of the second surface to be a surface, between the external connection terminals for signals on the second surface.

In the above-described surface acoustic wave device, it is preferable that each signal external connection terminal having a ground external connection terminal is disposed adjacent to each other. In the surface acoustic wave device, a plurality of grounding external connection terminals may be arranged between adjacent signal external connection terminals. In the surface acoustic wave device, each of the signal external connection terminals may be for input. In the surface acoustic wave device,
Each of the external connection terminals for signals may be for output.
In the surface acoustic wave device, each external connection terminal for a signal is:
They may be for input and output respectively.

According to the above configuration, the surface acoustic wave element is mounted face-down on the first surface of the holding substrate by the metal bump, so that the surface acoustic wave element is placed between the surface acoustic wave element and the holding substrate. I can secure space for movement,
The operation of the surface acoustic wave element can be ensured.

Further, in the above configuration, since the electrical and mechanical coupling between the surface acoustic wave element and the holding substrate can be performed within the surface area of the surface acoustic wave element, the size of the holding substrate can be reduced. .

Further, in the above configuration, since each external connection terminal is formed along the periphery of the second surface of the holding substrate, it is possible to suppress occurrence of conduction (short circuit) between the external connection terminals.

[0014] In addition, in the above configuration, since the grounding external connection terminals are arranged between the signal external connection terminals, the pitch of the external connection terminals is reduced by downsizing the holding substrate. However, since the bridging capacitance generated between the external connection terminals can be reduced, the propagation characteristic of each signal passing through each external connection terminal can be suppressed from being deteriorated by the bridging capacitance, and the propagation characteristic of each signal can be reduced. It can be improved compared to the past.

In the surface acoustic wave device, a plurality of surface acoustic wave elements may be provided on the first surface of the holding substrate.

According to the above configuration, a plurality of surface acoustic wave elements are provided, the number of external connection terminals is increased, and even if the pitch between the external connection terminals is further narrowed, the external connection for grounding is provided between them. By providing the terminals, the bridging capacitance generated between the external connection terminals can be reduced. Therefore, even in a multi-chip structure including a plurality of surface acoustic wave elements, the propagation characteristics of each signal can be improved as compared with the related art.

In the above-described surface acoustic wave device, the surface acoustic wave element is connected to the piezoelectric substrate, each comb-shaped electrode for generating and detecting a surface acoustic wave on the piezoelectric substrate, and each comb-shaped electrode. An electronic component package having the holding substrate is provided so as to house the surface acoustic wave element, and the electronic component package is connected to the element electrodes by the metal bumps, respectively. Each internal electrode may be provided on the first surface of the holding substrate and connected to each external connection terminal.

According to the above configuration, since the surface acoustic wave element can be housed in the electronic component package and mounted face down by metal bumps, the operation of each comb-shaped electrode on the piezoelectric substrate can be stabilized. Handling can be facilitated by the component package.

According to a third aspect of the invention, a communication apparatus includes any one of the above-described surface acoustic wave devices.

According to the above configuration, since the surface acoustic wave device is downsized and has excellent signal propagation characteristics, the size can be reduced while improving the transmission and reception characteristics.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(First Embodiment) As shown in FIGS. 1 and 2, a surface acoustic wave device according to a first embodiment of the present invention has a substantially rectangular parallelepiped shape for an electronic component such as a surface acoustic wave element. A package 1, which is a bottomed container having an outer shape, is provided. The package 1 is formed of a material having electrical insulation. Examples of the material include plastics such as glass epoxy resin and ceramics such as alumina. Ceramics having better heat resistance and corrosion resistance than plastics are preferable.

The package 1 has a package bottom (second surface) 1a, a bottom plate 1b, a side wall 1c, and a cap (lid).
1d, a cavity 1 capable of housing a surface acoustic wave element 3 surrounded by a bottom plate 1b, a side wall 1c, and a cap 1d.
e. An inner surface (first surface) 1g of the bottom plate portion 1b opposite to the package bottom surface 1a.
On the top, each electrode portion 1f for conducting the surface acoustic wave element 3 to the outside is formed.

On the outer surface of the package 1, more preferably, on the package bottom surface 1a on the bottom side of the end surface in the thickness direction,
An external connection terminal 2 made of a conductive metal, for example, silver or the like is used to connect each surface acoustic wave element 3 described below to an external circuit.
Are provided at a plurality of, for example, six terminals, at each corner of the package bottom surface 1a, and at the center of each side in the longitudinal direction. Further, each external connection terminal 2 is electrically connected to each corresponding electrode portion 1f via a side surface portion or the inside (through hole such as a via hole) of the bottom plate portion 1b.

Further, the package 1 of the surface acoustic wave device comprises:
A plurality of, for example, two surface acoustic wave devices 3 are provided in the cavity 1e inside the cavity 1e. Each surface acoustic wave element 3
Using a surface acoustic wave, a signal can be converted, for example, a signal in a pass band can be passed to suppress a signal outside the pass band, an impedance can be converted, or an unbalanced signal-balanced signal conversion function can be provided. Things.

Each surface acoustic wave element 3 has a substantially rectangular parallelepiped shape, and its longitudinal sides are arranged in parallel with each other and are hermetically sealed in the cavity 1e of the package 1. Details of the surface acoustic wave element 3 will be described later. As a result, the surface acoustic wave device has a multi-filter structure in which each surface acoustic wave element 3 functions independently.

Each of the surface acoustic wave elements 3 is mounted face down on the package 1 by the flip chip method in the cavity 1e inside the package 1.
That is, each electrode pad (element electrode) of the surface acoustic wave element 3
Electrical continuity between 3a, 3b and each electrode portion 1f of the package 1 formed at a position facing each of them is ensured by the interposition of the metal bumps 10. further,
Each surface acoustic wave element 3 is mechanically held in the package 1 by the bonding force of the metal bump 10.

The surface acoustic wave element 3 has a plurality of interdigital electrodes (also referred to as interdigital electrodes) formed on the surface thereof.
An Inter-Digital Transducer (hereinafter, referred to as IDT) is mounted on the bottom plate 1b facing the bottom plate 1b with a space between the IDT and the bottom plate 1b, that is, face-down mounted. By such face-down mounting, the operation of the surface acoustic wave element 3 in each IDT can be ensured by the space.

Further, by the face-down mounting by the flip-chip method, the electrical and mechanical coupling between the surface acoustic wave element 3 and the package 1 can be facilitated and the size can be reduced.

This is because each IDT faces the bottom plate portion 1b, so that the input / output wiring pattern from each IDT can be simplified, and the electrical connection can be made by the metal bumps 10, that is, by the flip chip method. This is because the connection and the mechanical connection can be combined.

In such a flip chip method, since each electrode portion 1f can be formed within the surface area of the surface acoustic wave element 3, it is necessary to provide an electrical connection portion outside the surface direction of the surface acoustic wave element. The overall volume of the package 1 can be reduced as compared with the case of a package using a wire bonding method or the like.

When the surface acoustic wave element 3 has, for example, an unbalanced input and an unbalanced output, of the six external connection terminals 2 of the package 1, two terminals are used for input (for signal), that is, for each input. External connection terminals 2a, 2b, two terminals for output (for signals), that is, external connection terminals 2c, 2d for each output
Is required.

From this, it can be seen that each input external connection terminal 2
a, 2b on the end face in the thickness direction of the package 1;
C, which is each corner of one end (first end) in the longitudinal direction,
D, the output external connection terminals 2c and 2d are connected to the other end in the longitudinal direction (the second end opposite to the first end) on the end surface in the thickness direction of the package 1. Are arranged at F and A.

The grounding external connection terminals 2e, 2f
And the end face (bottom face) in the thickness direction of the package 1, respectively.
Above, a position that is approximately the center of each side in the longitudinal direction, B, E
Has been placed. Thereby, the grounding external connection terminal 2e
Are the input external connection terminal 2a and the output external connection terminal 2d
, More preferably, the input external connection terminal 2a
And the output external connection terminal 2d are arranged at equal intervals. Further, the grounding external connection terminal 2f is interposed between the input external connection terminal 2b and the output external connection terminal 2c, and more preferably, is equidistant from the input external connection terminal 2b and the output external connection terminal 2c. It is arranged at the position where

Next, the operation of the surface acoustic wave device will be described.
The effect will be described. In the above-described surface acoustic wave device, in particular, when a multi-chip structure is adopted by a flip-chip method, multi-functionalization and miniaturization can be realized at the same time. The external connection terminals 2 need to be formed. As a result, the distance between adjacent external connection terminals 2 is reduced.

For example, when the external connection terminals 2 for signal (input / output) are adjacent to each other in the package 1 having a pitch (interval) of about 1.0 mm between adjacent external connection terminals 2,
When the capacitance between the external connection terminals 2 was measured between the external connection terminals 2, for example, when the grounding external connection terminals 2 e were arranged, the capacitance between the external connection terminals 2 was about 0.1 pF when adjacent.
Was obtained.

This inter-terminal capacitance becomes a bridging capacitance between input and output. Based on this capacitance difference, a conventional surface acoustic wave device using a package in which an input external connection terminal and an output external connection terminal are adjacent to each other, and an input external connection terminal 2a as in the present invention. FIG. 3 is a graph showing the result of simulating the characteristic difference between each surface acoustic wave device and the surface acoustic wave device using the package 1 in which the grounding external connection terminal 2e is arranged between the output external connection terminal 2d. Show.

That is, in the conventional case where the input external connection terminal and the output external connection terminal are adjacent to each other, the ground external connection terminal 2e is arranged between the input external connection terminal 2a and the output external connection terminal 2d. The case where the capacity between input and output was reduced was compared as the present invention.

As in the present invention, the grounding external connection terminal 2e is provided between the input external connection terminal 2a and the output external connection terminal 2d.
The bridge capacity between input and output could be reduced by arranging. As a result, as shown in FIG. 3, in the conventional example, the electric signal is transmitted directly from the external connection terminal for input to the external connection terminal for output, so that the attenuation outside the band is deteriorated. Has been improved, and a large amount of attenuation outside the band can be realized.

In other words, compared to the conventional example in which the input external connection terminal and the output external connection terminal are adjacent to each other, in the present invention, for example, between the input external connection terminal 2a and the output external connection terminal 2d By arranging at least one external connection terminal 2e for grounding, it has become clear that clearly excellent filter characteristics (frequency characteristics) can be obtained.

(Second Embodiment) A surface acoustic wave device according to a second embodiment of the present invention will be described with reference to FIG. The surface acoustic wave device has a package 4 having the same function and shape as the package 1 described above, except that the number and arrangement of the external connection terminals 2 are different. The package 4 has eight external connection terminals 5 for connection to an external circuit. In addition, the surface acoustic wave device is a package 4
Has two surface acoustic wave elements 6 side by side inside
Each surface acoustic wave element 6 has a multi-filter structure that functions independently.

Each of the surface acoustic wave elements 6 is mounted face-down inside the package 4. Each surface acoustic wave element 6 and package 4 are formed by metal bumps 10 as in FIG.
And electrical continuity between them. Metal bump 10
Accordingly, each surface acoustic wave element 6 is mechanically held inside the package 4.

Each surface acoustic wave element 6 has an unbalanced input and an unbalanced output. Therefore, the eight external connection terminals 5 of the surface acoustic wave device require two terminals for input and two terminals for output. The input external connection terminals 5a and 5b are connected to the corners C and E of one end (third end) in the short direction of the package bottom surface 4a on the bottom surface side of the end surface in the thickness direction of the package 4. The output external connection terminals 5c and 5d are connected to the other end in the short direction (fourth end opposite to the third end) on the end surface in the thickness direction of the package 4. , G and A.

In the surface acoustic wave device package 4, the four external connection terminals 5e, 5f, 5
g, 5h is preferably substantially an intermediate portion (the center of each side of the bottom surface) between the adjacent terminals of the input external connection terminals 5a, 5b and the output external connection terminals 5c, 5d. It is arranged at each position B, D, F, H.

Next, the operation of the surface acoustic wave device will be described.
The effect will be described. In the second embodiment, similar to the first embodiment, adjacent input external connection terminals 5a, 5a
By arranging the grounding external connection terminals 5e and 5g between b and the output external connection terminals 5c and 5d, the same operation and effect as in the first embodiment can be expected.

In the second embodiment, the grounding external connection terminals 5a and 5b connected between different surface acoustic wave elements 6 and the output external connection terminals 5c and 5d are connected. By arranging the connection terminals 5f and 5h, the bridging capacitance generated between the input external connection terminals 5a and 5b and between the output external connection terminals 5c and 5d can also be reduced.

From the above, in the surface acoustic wave device,
Crosstalk between filters formed by the respective surface acoustic wave elements 6 is suppressed, and as a result, good multi-filter characteristics can be obtained by improving attenuation and reducing unnecessary response.

Third Embodiment A surface acoustic wave device according to a third embodiment of the present invention will be described below with reference to FIG. In the surface acoustic wave device, each external connection terminal 2
A package 7 having, for example, ten external connection terminals 8 having different numbers and arrangements is provided in place of the packages 1 and 4 described above. This package 7 has the same functions and configurations as those of the packages 1 and 4 except for the external connection terminals 8. Further, the surface acoustic wave device has two surface acoustic wave elements 9 inside the package 7, and each of them has a multi-filter structure that functions independently.

Each of the surface acoustic wave elements 9 is mounted face-down inside the package 7. Each surface acoustic wave element 9 and package 7 are formed by metal bumps 10 as in FIG.
And electrical continuity between them. Metal bump 10
Accordingly, each surface acoustic wave element 9 is mechanically held inside the package 7.

Each of the surface acoustic wave elements 9 has an unbalanced input and a balanced output. Therefore, each external connection terminal 8 of the surface acoustic wave device has two terminals for input and four terminals for output.
Terminals are required. That is, each input external connection terminal 8
a and 8b are arranged at respective positions D and E of the rectangular package bottom surface 7a. Each output external connection terminal 8c,
8d, 8e, and 8f are the respective positions A on the package bottom surface 7a.
B, G, and H. External connection terminal 8 for each ground
g, 8h, 8i, and 8j are arranged at respective positions C, F, I, and J on the package bottom surface 7a.

Each of the positions C and A is a corner at one end in the longitudinal direction on the package bottom surface 7a. Each position F,
H is a corner at the other end in the longitudinal direction of the package bottom surface 7a, and is a position facing each of the positions C and A in the longitudinal direction of the package bottom surface 7a. Position B
Is the package bottom surface 7a between the position C and the position A.
Is located substantially at the center of the longitudinal end of the.

As a result, the output external connection terminal 8d at the position B is arranged at a substantially intermediate position between the ground external connection terminal 8g and the output external connection terminal 8c, and the position D The external connection terminal for ground 8g is interposed between the external connection terminal for input 8a and the external connection terminal for input 8a.

The output external connection terminal 8 at the position G
e is the external connection terminal 8h for ground and the external connection terminal 8 for output.
f, and the grounding external connection terminal 8h is interposed between the input external connection terminal 8b at the position E and the input external connection terminal 8b.

Further, the output external connection terminal 8c at the position A
And the output external connection terminal 8f at the position H, the two external ground connection terminals 8j and 8i are adjacent to the output external connection terminal 8c, the external ground connection terminal 8j, and the external ground connection terminal 8j. The connection terminals 8i and the output external connection terminals 8f are arranged so as to have substantially equal intervals.

Thus, with the arrangement of the grounding external connection terminals 8j and 8i, one set of the output external connection terminals 8c and 8d and the other set of the output external connection terminals 8e and 8e are provided. 8f can be shielded.

Next, the operation of the surface acoustic wave device will be described.
The effect will be described. Since the third embodiment has a multi-filter and a balanced output, a total of six signal (input / output) external connection terminals are required, and a large number of external connection terminals 8 are required. It is important to reduce the influence between the external connection terminals for each signal.

In the third embodiment, similarly to the first embodiment, a grounding external connection terminal 8g is arranged between adjacent input external connection terminals 8a and output external connection terminals 8d, for example. The same operation as in the first embodiment can be expected. Further, in the third embodiment, each adjacent external connection terminal 8 for output connected to a different surface acoustic wave element 9 is used.
By arranging the ground external connection terminals 8j and 8i between c and 8f, the capacitance between the output external connection terminals 8c and 8f can be reduced.

From the above, in the surface acoustic wave device,
Crosstalk between the filters composed of the respective surface acoustic wave elements 9 is suppressed, and as a result, good multi-filter characteristics can be obtained by improving attenuation and suppressing unnecessary response.

The surface acoustic wave element 9 used in the third embodiment will be described below with reference to FIG.

The surface acoustic wave element 9 is, as shown in FIG.
For example, an IDT 11 is formed by an Al electrode formed by a photolithography method or the like on a substrate 30 having a piezoelectricity made of, for example, 40 ± 5 ° YcutX propagation LiTaO ₃ . FIG. 6 is a schematic configuration diagram of an electrode finger of a surface acoustic wave element 9 mounted on a surface acoustic wave device according to a third embodiment of the present invention.

In the surface acoustic wave element 9, the IDTs 12 and 13 on the unbalanced side are arranged on the left and right sides (along the propagation direction of the surface acoustic wave) of the IDT 11 on the balanced side, and these IDTs 12 and 13 are sandwiched. Reflector 14, 1
A longitudinally coupled resonator type surface acoustic wave element section 16 is formed as a longitudinally coupled resonator type surface acoustic wave filter on which 5 is formed.

Each of the IDTs 11, 12, and 13 has an electrode finger portion having a strip-shaped base end (bus bar) and a plurality of mutually parallel electrode fingers extending in a direction perpendicular to one side of the base end. And each of the electrode finger portions is provided in such a manner that the electrode finger side portions of the electrode finger portions are interposed between the electrode fingers so as to face each other.

In such IDTs 11, 12, and 13,
By setting the length and width (pitch) of each electrode finger, the interval between each adjacent electrode finger, and the cross width indicating the length of facing each other between the electrode fingers, the signal conversion characteristics and the passage Each setting of the band is possible. It is also assumed that other IDTs described later have similar configurations and functions.

Further, in the surface acoustic wave element 9, a surface acoustic wave resonator 20 having reflectors 18 and 19 formed so as to sandwich the IDT 17 on the unbalanced side is connected in series to each of the IDTs 12 and 13. And also
The balanced signal terminals 21 and 22 are connected to the IDT 11, and the unbalanced signal terminal 23 is connected to the IDT 17.

The surface acoustic wave device 9 of the third embodiment is
This configuration avoids forming an electrical neutral point between the balanced signal terminals 21 and 22.
12, and between IDT11 and IDT13,
For example, the pitch of the eight electrode fingers is made smaller than the other parts of each IDT (at points 25 and 26 in FIG. 6),
11, 12, and 13 are set to maintain continuity. Incidentally, FIG. 6 shows a small number of electrode fingers to simplify the drawing.

The detailed design is as follows. The wavelength determined by the pitch of the electrode fingers whose pitch between the IDTs is reduced is λI ₂ , and the wavelength determined by the pitch of other non-narrow electrode fingers is λ
Assuming that I ₁ , an example of the longitudinally coupled resonator type surface acoustic wave element 9 is as follows, for example. Intersection width W: 80.5λI Number of IDTs (in the order of IDT12, IDT11, and IDT13): 23 (4) / 34 (4) / 23 (4) (the number of electrode fingers with reduced pitch in parentheses) IDT wavelength λI ₁ : 2.1746 μm, λI ₂ : 1.9
609 μm Reflector wavelength λR: 2.1826 μm Number of reflectors: 150 IDT-IDT interval: electrode finger of wavelength λI ₁ and wavelength λI ₂
Of the electrode finger (26 in FIG. 6): 0.25λI
₁ + 0.25λI ₂ Location sandwiched between electrode fingers of wavelength λI ₂ (27 in FIG. 6):
0.50λI ₂ IDT- reflector gap: 0.46λR IDTduty: location wavelengths λI _1: 0.63 Wavelength RamudaI ₂ places: 0.60 Reflector duty: 0.57 electrode thickness: a 0.09λI _1.

For the surface acoustic wave resonator 20, the cross width W: 23.7λI The number of IDTs: 241 The IDT wavelength λI: 2.1069 μm The reflector wavelength λR = λI The number of reflectors: 30 IDT-reflector interval: 0.50λR IDT duty: 0.60 Reflector duty: 0.60 Electrode film thickness: 0.09λI.

Such a surface acoustic wave element 9 has a balun function as a balance-unbalance conversion function.
A balun is undesirable when a balanced line such as a parallel two-wire feeder is directly connected to an unbalanced line such as a coaxial cable, because an unbalanced current flows and the feeder itself operates as an antenna. , A circuit that prevents the generation of unbalanced current and matches the balanced line with the unbalanced line.

In the first embodiment, for example, the grounding external connection terminals 2e,
The example in which the installation position of 2f is provided substantially at the center (equidistant position) on a straight line connecting the input external connection terminals 2a and 2b and the output external connection terminals 2d and 2c has been described. 2a, 2b and output external connection terminals 2d, 2d
It may be between c.

As such a position, for example, the diameter of the input external connection terminal 2a centered on the intermediate position is set.
And a virtual circle which is the interval between the output external connection terminals 2d,
More preferably, the inside of an imaginary circle whose diameter is の of the above-mentioned interval is used.

In the second and third embodiments, the positions of the grounding external connection terminals are the same. However, in the case where a plurality of grounding external connection terminals are provided between the input and output signal external connection terminals, the plurality of grounding external connection terminals are interposed between the signal external connection terminals. There are positions where the external connection terminals for grounding are arranged at equal intervals.

In the surface acoustic wave device according to the present invention as described above, the adverse effect due to the above-mentioned bridging capacitance becomes large.
Since the signal characteristics outside the passband and above the passband above 1 MHz, especially above 1 GHz are more excellent in reducing the bridging capacity, mobile phones and bluetooth
It is suitably used for electronic devices (electronic parts) such as filters and baluns of communication equipment using signals of 100 MHz or more, especially GHz or more, as in h).

(Fourth Embodiment) Next, a communication device 100 equipped with the surface acoustic wave device according to any one of the first to third embodiments of the present invention will be described with reference to FIG. The communication apparatus 100 includes an antenna 101 and an antenna sharing unit /
RFTop filter 102, amplifier 103, Rx interstage filter 104, mixer 105, 1st IF filter 10
6. Mixer 107, 2nd IF filter 108, 1st
+ 2nd local synthesizer 111, TCXO (temp
It is provided with an erature compensated crystal oscillator (temperature compensated crystal oscillator) 112, a divider 113, and a local filter 114. As shown by two lines in FIG. 7, it is preferable to transmit each balanced signal from the Rx interstage filter 104 to the mixer 105 in order to ensure balance.

Further, the communication apparatus 100 serves as a transceiver side (Tx side) for transmitting data,
And the above-mentioned common antenna / RFTop filter 102
And a Tx IF filter 121, a mixer 122, a Tx interstage filter 123, an amplifier 124, a coupler 125, an isolator 126, an APC (automatic power supply).
er control (automatic output control) 127.

Then, the Rx inter-stage filter 104,
1st IF filter 106, TxIF filter 121,
The surface acoustic wave device according to any one of the first to third embodiments described above can be suitably used for the Tx interstage filter 123.

Therefore, in the above communication device, since the surface acoustic wave device used is miniaturized and has excellent propagation characteristics, a high frequency band (MHz band or more),
Especially in the GHz band or higher, miniaturization and improvement of transmission / reception characteristics can be achieved.

[0077]

As described above, the surface acoustic wave device of the present invention electrically connects the surface acoustic wave element mounted face-down on the first surface of the holding substrate with the metal bumps to an external circuit. External connection terminals for signals are formed along a peripheral portion of a second surface opposite to the first surface of the holding substrate, and on the second surface, each external connection terminal for signals is formed. In this configuration, a grounding external connection terminal is arranged therebetween.

Therefore, the above configuration can reduce the bridging capacitance between the external connection terminals for signals such as input and output by sandwiching the external connection terminal for ground between them. In particular, when a plurality of surface acoustic wave elements are provided, crosstalk between the surface acoustic wave elements can be suppressed.

As a result, the above configuration has an effect that the signal propagation characteristics such as the filter characteristics of the surface acoustic wave element provided on the holding substrate can be improved and improved.

As described above, the communication device of the present invention has the above-described surface acoustic wave device. Therefore, the above configuration has a surface acoustic wave device with improved signal propagation characteristics, and has an effect of being excellent in transmission and reception characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an arrangement of an input external connection terminal, an output external connection terminal, and a ground external connection terminal in a surface acoustic wave device according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view of the surface acoustic wave device.

FIG. 3 is a graph showing a difference in characteristics between the surface acoustic wave device and a conventional example.

FIG. 4 is a schematic explanatory view showing the arrangement of an input external connection terminal, an output external connection terminal, and a ground external connection terminal in a surface acoustic wave device according to a second embodiment of the present invention.

FIG. 5 is a schematic explanatory view showing an arrangement of an input external connection terminal, an output external connection terminal, and a ground external connection terminal in a surface acoustic wave device according to a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a surface acoustic wave element used in the surface acoustic wave device.

FIG. 7 is a main block diagram of the communication device of the present invention.

[Explanation of symbols]

 1a Package bottom surface (second surface) 1b Bottom plate (holding substrate) 1g Internal surface (first surface) 2a Input external connection terminal 2b Input external connection terminal 2c Output external connection terminal 2d Output external connection terminal 2e External connection terminal for grounding 2f External connection terminal for grounding 3 Surface acoustic wave element

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazunobu Shimoe 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto F-term in Murata Manufacturing Co., Ltd. (Reference) 5J097 AA10 DD04 DD13 DD16 GG03 HA04 JJ08 JJ09 KK10

Claims (9)

[Claims] 1. A surface acoustic wave element for converting an input signal by a surface acoustic wave and outputting the converted signal is face-down mounted on a first surface of a holding substrate by a metal bump, and the surface acoustic wave element is connected to an external circuit. For electrical connection, an external connection terminal for a signal is formed along a peripheral portion of a second surface opposite to the first surface of the holding substrate, on the second surface, A surface acoustic wave device characterized in that a grounding external connection terminal is arranged between signal external connection terminals. 2. The surface acoustic wave device according to claim 1, wherein each of the signal external connection terminals having an external ground connection terminal is disposed adjacent to each other. 3. The surface acoustic wave device according to claim 1, wherein a plurality of grounding external connection terminals are arranged between adjacent signal external connection terminals. 4. The surface acoustic wave device according to claim 1, wherein each of the signal external connection terminals is for input. 5. The surface acoustic wave device according to claim 1, wherein each of the signal external connection terminals is for output. 6. The surface acoustic wave device according to claim 1, wherein each of the signal external connection terminals is for input and output. 7. The surface acoustic wave device according to claim 1, wherein a plurality of surface acoustic wave elements are provided on the first surface of the holding substrate. 8. A surface acoustic wave element comprising: a piezoelectric substrate; comb electrodes for generating and detecting a surface acoustic wave on the piezoelectric substrate; and device electrodes connected to the comb electrodes, respectively. An electronic component package having the holding substrate is provided so as to house a surface acoustic wave element, and the electronic component package includes an internal electrode connected to the element electrode by the metal bump. The surface acoustic wave device according to any one of claims 1 to 7, wherein the surface acoustic wave device is provided on the first surface of the holding substrate so as to be connected to each of the external connection terminals. 9. A communication device comprising the surface acoustic wave device according to claim 1.