JP3442804B2 - Surface acoustic wave device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device capable of sufficiently suppressing direct waves of electric signals.

[0002]

2. Description of the Related Art FIG. 7 is a plan view showing a conventional surface acoustic wave device disclosed in, for example, Japanese Unexamined Patent Publication No. 3-220911, in which 1 is a surface acoustic wave chip (hereinafter simply referred to as a chip). ) 2 is a package, and the chip 1 is mounted on the center of the mounting surface 2a of the package 2. Further, 3 is an input signal terminal, 4 is an output signal terminal, 5a is an input side ground terminal, and 5b is a first surface provided on a mounting surface 2a on which the chip 1 is mounted and connected to the input side ground terminal 5a. A metallized portion, 6a is an output side ground terminal, and 6b is a second metallized portion provided on the mounting surface 2a and connected to the output side ground terminal 6a.

The chip 1 includes an input signal pad 10a,
An output signal pad 11a, an input side ground pad 10b and an output side ground pad 11b are provided, and these pads are respectively the input signal terminal 3, the output signal terminal 4, the input side ground terminal 5a, the output side ground terminal 6a and the metal wire. It is electrically connected via 8. Further, 13a is an input signal pack.
And ground pads on the input side are electrically connected to each
Input side comb-shaped electrode composed of a plurality of electrodes, 13b is an output signal
Electrically connected to each pad and output side ground pad
The output-side comb-shaped electrode is composed of a plurality of electrodes. In addition,
The first metallization part is between the package 2 and the chip 1.
The second comb-shaped electrode 13a is provided so as to overlap with the input-side comb-shaped electrode 13a.
The metallization section outputs between package 2 and chip 1.
It is provided so as to overlap the side comb electrodes 13b.

Next, the operation will be described. In this surface acoustic wave element, the first metallized portion 5b and the second metallized portion 6b, which are grounded, are provided on the mounting surface 2a on which the chip 1 is mounted.
The space surrounding the package and the outside of the package 2 are electrically isolated from each other to prevent unwanted signals from entering and exiting.

[0005]

Since the conventional surface acoustic wave device is constructed as described above, the first metallized portion 5b and the second metallized portion 6b must be adjacent to each other and are called direct waves. There is a problem that it is impossible to suppress unnecessary signals such as direct transmission of electric signals due to capacitive coupling.

The present invention has been made to solve the above problems, and an object thereof is to obtain a surface acoustic wave element capable of sufficiently suppressing direct waves of electric signals.

[0007]

A surface acoustic wave device according to a first aspect of the present invention includes a surface acoustic wave element having input-side and output-side comb-teeth electrodes, a chip including the surface acoustic wave element, and the chip. A package having a mounting surface on which is mounted, one and the other step portions respectively provided on the mounting surface on both sides of the chip, and provided on the one step portion at a predetermined interval. An input signal terminal and an output side ground terminal, and an input side ground terminal and an output signal terminal that are provided at a predetermined interval on the other step portion and are arranged to face the input signal terminal and the output side ground terminal, respectively. , The input signal terminal continuously from the input side ground terminal
It extends to near the child and faces the input side comb-teeth electrode
The first metallization portion provided on the mounting surface and the output side contact
Continuously extend from the ground terminal to the vicinity of the output signal terminal,
It was provided on the mounting surface facing the output side comb-teeth electrode.
A second metallization part, the first metallization part and the second metallization part
Extending to the lower surface of the chip between the metallization ,
Between a third metallization portion provided on the mounting surface, the input signal terminal on the one step portion and the output side ground terminal, and the output signal terminal and the input side on the other step portion. The third metal is provided between the third metal and the ground terminal, respectively.
A third grounding terminal connected to each riser, and a connecting means electrically connecting the surface acoustic wave device to the input signal terminal, the output signal terminal, the input side grounding terminal, and the output side grounding terminal. Be prepared.

The surface acoustic wave device according to the invention of claim 2 is
A surface acoustic wave element having input-side and output-side comb-teeth electrodes;
A chip having the surface acoustic wave element, a package having a mounting surface on which the chip is mounted, an input signal terminal and an output signal terminal arranged to face the mounting surface on both sides of the chip, Between the input signal terminal and the output signal terminal, on the mounting surface, while extending in the direction perpendicular to the arrangement direction of the input signal terminal and the output signal terminal, the input side and the output side. It has a width corresponding to the comb-teeth electrode and is located in the vertical direction of the chip.
A third metallized portion having narrow portions formed on both sides thereof, and a third metallized portion in the vertical direction.
Third ground terminals respectively connected to both ends of the input signal terminals, input side ground terminals respectively provided on the mounting surfaces on both sides of the input signal terminal in the vertical direction , the third metallized portion and the third metal terminal . a first metallization which the is continuously both input-side grounding terminal as spaced apart from the ground terminal to surround the input signal terminals of the vertical of the output signal terminal
The output side grounding terminals respectively provided on the mounting surfaces on both sides in the direction , the third metallized portion and the third metallized portion .
Second metallized portion in which both the output side ground terminals are connected so as to surround the output signal terminal while being separated from the ground terminal, and the surface acoustic wave element and the input signal terminal, the output signal terminal, the input side ground And a connection means for electrically connecting the terminal and the output-side ground terminal, respectively.

A surface acoustic wave device according to the invention of claim 3 is
Wherein the lid of the conductor provided in the package, but the lid according to claim 1 or 2 and electrically connected to the third ground terminal.

A surface acoustic wave device according to a fourth aspect of the present invention is
The chip has an input signal pad and an output signal pad .
4. A shield electrode is provided between these pads, and the shield electrode is electrically connected to the third ground terminal. It is a thing.

[0011]

According to the third aspect of the present invention ,
Between the first metallized portion and the second metallized portion
It is on the mounting surface described above and is extended to the lower surface of the chip.
Thus, unnecessary signals such as direct waves are suppressed.

A third metallized portion according to the invention of claim 2
Form a narrow portion, and the first metallized portion is the third metallized portion.
Separate the input signal terminal from the noise section so that both
The ground terminal on the input side is connected continuously, and the second metallized portion is
Enclose the output signal terminal apart from the third metallized portion
Since both output side grounding terminals are connected continuously,
Suppress unnecessary signals such as.

In the surface acoustic wave device according to the third aspect of the present invention, since the lid made of a conductor is electrically connected to the third ground terminal, the inside and outside of the package is electrically shielded, and the direct wave or the like is transmitted. Suppresses unnecessary signals.

Further, in the surface acoustic wave device according to the invention as defined in claim 4 , since the shield electrode of the chip is electrically connected to the third ground terminal, the direct wave transmitted near the surface of the chip is reduced. , Suppress unnecessary signals.

[0015]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. Figure 1
1 to 3 are views showing a first embodiment of the present invention, and in these figures, the same components as those in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted.

The package 2 includes an input signal terminal 3, an output signal terminal 4, an input side ground terminal 5a, and an output side ground terminal 6.
a, a ground terminal 5a on the input side, and a ground terminal 6a on the output side, and a third ground terminal 7a electrically insulated from each other are provided,
The input signal terminal 3, the output signal terminal 4, the input side ground terminal 5a, and the output side ground terminal 6a respectively correspond to the input signal pad 10a and the output signal pad 11 on the chip 1.
a, input side ground pad 10b, output side ground pad 11b
It is connected with a metal wire 8.

Further, a first metallized portion 5b connected to the input side ground terminal 5a and a first metallized portion 5b are provided on the chip mounting surface.
The output side grounding terminal 6 is arranged apart from the metallized portion of
A third metallized portion 7b connected to the third ground terminal 7a is provided adjacent to each metallized portion between the second metallized portion 6b connected to a. Further, as is clear from the figure, the gap between the first metallized portion and the third metallized portion and the gap between the second metallized portion and the third metallized portion are both these three metallized portions. It is narrower than the width of the section. In addition, the input side ground terminal 5a, the output side ground terminal 6a, and the third ground terminal 7
The element a is connected to the ground terminal of the circuit outside the package 2 when the element is actually mounted on a circuit board or the like and used.

As described above, according to the surface acoustic wave device of the first embodiment, the first metallized portion 5b and the second metallized portion 6b are no longer adjacent to each other, and the direct wave or the like, which has been a problem in the past, is generated. Unwanted signals can be suppressed. The gap between the first metallized portion and the third metallized portion and the gap between the second metallized portion and the third metallized portion are both narrower than the widths of these three metallized portions. Therefore, even if the metallized portion for grounding provided at the position corresponding to the chip mounting surface is divided into three, electromagnetic waves leaked from these gaps are prevented from wrapping around. The electromagnetic wave can be shielded by these three metallized portions.

FIG. 2 is a view showing a modification of the above embodiment, in which the chip mounting surface and the terminal arrangement surface such as the input signal terminal are three.
It is a surface acoustic wave device that is dimensionally configured. In this element, a first metallized portion 5b and a second metallized portion 6b are provided on the mounting surface of the chip with the third metallized portion 7b interposed therebetween. Also in this element, the same effect as that of the above-mentioned embodiment is obtained.

FIG. 3 is a diagram in which the shape and arrangement of each terminal and each metallized portion of the above-mentioned embodiment is changed, and the same effect as that of the above-mentioned embodiment is obtained.

Example 2. Embodiment 2 of the present invention will be described below with reference to the drawings. Figure 4
5 and FIG. 5 are views showing a second embodiment of the present invention. In these figures, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

As shown in the drawing, by electrically connecting the third ground terminal 7a and the conductor lid 9 to each other, the direct wave between the input and the output can be prevented and the electric shielding effect inside and outside the package can be improved. This can be achieved, and it is possible to further reduce unnecessary waves.

Example 3. The third embodiment of the present invention will be described below with reference to the drawings. Figure 6
3A and 3B are diagrams showing a third embodiment of the present invention, in which the same components as those in FIG.

In FIG. 6, the chip 1 is a shield electrode 1.
By connecting the third ground terminal 7a to the third ground terminal 7a with the metal wire 8, the direct wave transmitted near the surface of the chip 1 is reduced, and the unnecessary signal can be suppressed more effectively.

In the above-mentioned embodiment, the chip 1 in which one comb-shaped electrode is provided on each of the input side and the output side is shown, but when a plurality of comb-shaped electrodes are provided on the input side or the output side, In addition to the comb-shaped electrode and the shield electrode, it can be applied to a surface acoustic wave device including a grating reflector or the like, and the same effect can be obtained.

[0026]

As described above , according to the present invention, the direct wave
Suppress unnecessary signals such as to obtain a high-performance surface acoustic wave device
be able to.

[0027]

[0028]

[0029]

[Brief description of drawings]

FIG. 1 is a plan view showing a surface acoustic wave device according to Example 1 of the present invention.

FIG. 2 is a perspective view showing a surface acoustic wave device of a modified example of the first embodiment of the present invention.

FIG. 3 is a plan view showing a surface acoustic wave device of a modified example of the first embodiment of the present invention.

FIG. 4 is a plan view showing a surface acoustic wave device of Example 2 of the present invention.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a plan view showing a surface acoustic wave device of Example 3 of the present invention.

FIG. 7 is a plan view showing a conventional surface acoustic wave element.

[Explanation of symbols]

1 surface acoustic wave chip (chip) 2 package 2a mounting surface 3 input signal terminal 4 output signal terminal 5a input side ground terminal 5b first metallized portion 6a output side grounded terminal 6b second metallized portion 7a third grounded terminal 7b Third metallized portion 9 Lid 10a Input signal pad 10b Input side ground pad 11a Output signal pad 11b Output side ground pad 12 Shield electrode 13a Input side comb-shaped electrode 13b Output side comb-shaped electrode

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Yoshida               8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric               Machine Co., Ltd., Communications Machine Works                (56) References JP-A-63-105509 (JP, A)                 JP 63-111713 (JP, A)                 JP-A-3-27611 (JP, A)                 Actual Kaihei 3-86623 (JP, U)

Claims (4)

(57) [Claims] 1. A surface acoustic wave device having input-side and output-side comb-teeth electrodes, and a chip having the surface acoustic wave device.
A package having a mounting surface on which the chip is mounted, one and the other step portions respectively provided on the mounting surfaces on both sides of the chip, and provided on the one step portion at a predetermined interval. The input signal terminal and the output side ground terminal, and the input side ground terminal and the output signal which are provided on the other step portion at a predetermined interval and are arranged to face the input signal terminal and the output side ground terminal, respectively. Terminals ,
Continuously near the input signal terminal from the input side ground terminal
On the mounting surface facing the input side comb-teeth electrode
First metallization portion provided on the output side and the output side ground terminal
Continuously extends from the output signal terminal to the output
A second member provided on the placement surface facing the side comb-teeth electrode.
And Taraizu portion, extends to the lower surface of the chip between said first metallization and the second metallization, the placing surface
Between the third metallized portion provided above and the input signal terminal and the output side ground terminal on the one step portion, and between the output signal terminal and the input side ground terminal on the other step portion. Between the third metallization
A third grounding terminal connected to each of the parts, and a connecting means electrically connecting the surface acoustic wave element and the input signal terminal, the output signal terminal, the input side grounding terminal, and the output side grounding terminal, respectively. A surface acoustic wave device characterized by the above. 2. A surface acoustic wave device having input-side and output-side comb-teeth electrodes, and a chip having the surface acoustic wave device.
A package having a mounting surface on which the chip is mounted, input signal terminals and output signal terminals arranged on both sides of the chip so as to face each other on the mounting surface, and these input signal terminals and output signal terminals And has a width corresponding to the input-side and output-side comb-teeth electrodes while extending in a direction perpendicular to the arrangement direction of the input signal terminal and the output signal terminal on the mounting surface. , said of the chip
A third metallized portion having narrow portions formed on both sides in the vertical direction, and the third metallized portion described above.
Third grounding terminals respectively connected to both ends in the vertical direction , input side grounding terminals respectively provided on the mounting surfaces on both sides of the input signal terminal in the vertical direction , the third metallized portion, and the A first metallized portion in which the input side ground terminals are connected to each other so as to surround the input signal terminal while being separated from a third ground terminal, and on the mounting surface on both sides of the output signal terminal in the vertical direction. And a second metallized section in which the output side ground terminals are connected to each other so as to surround the output signal terminal while being spaced apart from the output side ground terminal and the third metallized section and the third ground terminal. And a connection means for electrically connecting the surface acoustic wave element and the input signal terminal, the output signal terminal, the input side ground terminal and the output side ground terminal, respectively. Acoustic wave device. 3. The surface acoustic wave device according to claim 1, wherein the package has a conductor lid, and the lid is electrically connected to the third ground terminal. 4. The chip has an input signal pad and an output signal pad, a shield electrode is provided between these pads, and the shield electrode is electrically connected to the third ground terminal. The surface acoustic wave device according to any one of claims 1 to 3.