JP2000013173A - Surface acoustic wave device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device which does not need external parts at the time of connecting an inductance and whose performance is improved without considerably raising the resistance value of a wiring. SOLUTION: Relating to a surface acoustic wave device, terminals are formed at the side and the back of a package 1 and bonding pad parts 3a, 3b, 3c, 3d, 3e and 3f are given in accordance with the terminals. A bonding pad part 15 which is not connected to any terminal and a bonding pad part 18 which is not electrically connected to others are provided. The bonding pad parts 7 and 3e of a surface acoustic wave element 5 are wire-bonded by a wire 11, bonding pad parts 17 and 15 by a wire 19a, bonding pad parts 15 and 18 by a wire 19b and bonding pad parts 18 and 3b by a wire 19c. Then, they are electrically connected. The wires 19a, 19b and 19c are connected in series and a function as an inductor is given.

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 having an appropriate inductance.

[0002]

2. Description of the Related Art In general, a surface acoustic wave device may have an inductance connected in series to at least one of an input terminal and an output terminal in order to improve performance.

Conventionally, as a method of connecting such an inductance, for example, an external chip coil as an inductance is connected adjacent to an input terminal or an output terminal of a surface acoustic wave device.

However, in this method, since a chip coil as an external component is separately required, a mounting area becomes large when the surface acoustic wave device is mounted on a printed circuit board or the like. Also, in many cases, the required inductance value is several nH, whereas the value of the inductance itself is too large in the external component coil,
Difficult adjustments are required.

FIGS. 6 to 9 show another method.
Are known. 7 to 9 show a semi-finished product state.

This surface acoustic wave device has a package 1 made of insulating ceramics or plastic, and two terminals (not shown) and terminals 2b, 2c, 2e and 2f are formed on the side and back of the package 1. I have. On the surface of the package 1, these six terminals 2b, 2c,
Bonding pad portions 3a, 3b, 3c, 3 corresponding to 2e, 2f
d, 3e, 3f are electrically connected to the respective terminals 2b, 2c, 2e, 2f.

Further, on the surface of the package 1, a mounting surface 4 is formed at a position lower than the bonding pad portions 3a, 3b, 3c, 3d, 3e, 3f. And an inductance 6 of a routing wiring electrically connected to the surface acoustic wave element 5. Further, bonding pad portions 7 and 8 are formed so as to be electrically connected to the surface acoustic wave element 5 and the inductance 6, respectively.

The bonding pad 7 and the bonding pad 3e of the surface acoustic wave element 5 are wire-bonded with aluminum or gold wire 11.
The bonding pad portion 8 and the bonding pad portion 3b of the inductance 6 are wire-bonded by wires 12, and are electrically connected to each other.

As described above, if the inductance 6 is formed by routing the wiring, the size of the package 1 containing the surface acoustic wave element 5 does not change, and no external component such as a chip coil is required.

[0010] However, the inductance 6 of the routing wiring extremely increases the resistance value of the wiring itself, and lowers the Q of the inductance 6.

[0011]

As described above, when an inductor is externally mounted, a chip coil to be an external component is separately required, so that a surface acoustic wave device is mounted on a printed circuit board or the like. The area becomes large.
Further, in many cases, the required inductance value is several nH, whereas the value of the inductance itself is too large in the case of a coil of an external component, and a difficult adjustment is required.

On the other hand, when the inductance 6 is formed by the lead wiring, there is a problem that the resistance value of the wiring itself is extremely increased and the Q of the inductance 6 is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and does not require external parts when connecting an inductance in series, and has an elastic surface which improves performance without extremely increasing the resistance value of wiring. It is an object to provide a wave device.

[0014]

According to the present invention, there is provided a surface acoustic wave device, a terminal, a bonding pad portion electrically connected to the terminal, a bonding pad portion not electrically connected to the terminal, And a wire for connecting a bonding pad portion electrically connected to the terminal via a bonding pad portion not electrically connected to the terminal.

By connecting a bonding pad portion electrically connected to the terminal via a bonding pad portion not electrically connected to the terminal with a wire, the wire has an inductance function. The mounting area is not increased as compared with the case where the inductor is connected, and the Q of the inductor can be prevented from being reduced as compared with the case where the inductor is formed by the lead wiring.

In addition, a surface acoustic wave element, a terminal, a bonding pad portion electrically connected to the terminal, and a bonding pad portion that is not electrically connected,
The bonding pad portion electrically connected includes the terminal and a wire connecting the surface acoustic wave element.

[0017] By connecting the bonding pad portion electrically connected to the terminal via a bonding pad portion that is not electrically connected with a wire, an existing one can be used without newly forming a bonding pad portion. To make the wire have an inductance function,
It is possible to prevent the mounting area from being increased as compared with the case where an inductor is connected to the outside, and to prevent the Q of the inductor from being reduced as compared with the case where the inductor is formed by the routing wiring.

Further, since an inductor is connected to the terminal, a larger inductor can be accommodated by connecting the inductor to the outside.

Furthermore, the bonding pad portion is formed by printing, and is easy to form.

The bonding pad portions are electrically insulated by the grooves, and the creepage distance is increased by the grooves to ensure insulation.

Further, a plurality of bonding pad portions that are not electrically connected to the terminals are formed, and the bonding pad portions that are not electrically connected to the terminals are sequentially connected in series by wires. By making the overall length different, an inductor having an arbitrary value is obtained.

The wire is either an aluminum wire or a gold wire, and the workability is easy without increasing the resistance value more than necessary.

Further, the wire has a diameter of 20 μm to 4 μm.
Since it is 0 μm, it is easy to appropriately set the strength and the values of the resistance and the inductor.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a surface acoustic wave device according to the present invention will be described below with reference to the drawings. Parts corresponding to the conventional example shown in FIGS. 6 to 9 are denoted by the same reference numerals and described, and FIGS. 2 to 5 show semi-finished products.

This surface acoustic wave device has a package 1 made of insulating ceramics or plastic, and has six terminals 2a,
2b, 2c, 2d, 2e and 2f are formed. On the surface of the package 1, these six terminals 2a, 2b, 2c, 2d, 2e,
2f, the bonding pad portions 3a, 3b, 3c, 3d, 3
e, 3f are electrically connected to the respective terminals 2a, 2b, 2c, 2d, 2e, 2f, and connected to any of the terminals 2a, 2b, 2c, 2d, 2e, 2f at a part of the bonding pad portion 3a. An unbonded bonding pad portion 15 is formed. The bonding pad portions 3a, 3b, 3c, 3d, 3e, 3f, 15 are formed by a screen printing method or the like, and are separated by grooves 16, respectively, so that adjacent bonding pad portions 3a, 3b, 3c, 3d, 3e, 3f, 15
And are electrically insulated.

Further, on the surface of the package 1, a mounting surface 4 is formed at a position lower than the bonding pad portions 3a, 3b, 3c, 3d, 3e, 3f. Are formed. The surface acoustic wave element 5 is formed with bonding pads 7 and 17 electrically connected thereto, respectively, and also formed with a bonding pad 18 not electrically connected to other components.

The bonding pad 7 and the bonding pad 3e of the surface acoustic wave element 5 have a diameter of 20 μm.
To 40 μm aluminum or gold wire 11 and bonding pad portion 17
And the bonding pad portion 15 are wire-bonded with a wire 19a, the bonding pad portion 15 and the bonding pad portion 18 are wire-bonded with a wire 19b,
The bonding pad section 18 and the bonding pad section 3b are wire-bonded by wires 19c, and are electrically connected to each other. The wires 19a, 19b, and 19c are connected in series and have a function as an inductor.

The package 1 is closed with a lid (not shown).

As described above, by providing the wires 19a, 19b, and 19c with a function as an inductor, external components such as a chip coil are not particularly required, the resistance value of the wiring is not extremely increased, and the external dimensions are reduced. Performance can be improved without increasing. In addition, you may connect an external component as needed. Also, by extending the entire length of the wire, the inductor can be set to any value.

Although the package 1 has been described as having six terminals, the package 1 may have other terminals.

Further, the number of the bonding pad portions 15 not electrically connected is not limited to one, and a plurality of bonding pad portions 15 may be provided and connected by wires. In addition, a bonding pad portion 15 is used as a relay point, a metal portion that is not electrically connected to a terminal or the like is used, and a bonding pad portion that is not electrically connected to another is used as a relay point. Also, unlike the case of the lead-out wiring, the Q of the inductance does not decrease due to the increase in the resistance value. Further, since no external component coil is required, the external dimensions are not increased.

[0032]

According to the present invention, it is possible to improve the performance without particularly requiring external parts and without increasing the resistance value of the wiring extremely.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing a state of a semi-finished product of the surface acoustic wave device.

FIG. 3 is a sectional view of the surface acoustic wave device shown in FIG. 2 taken along the line III-III.

4 is a sectional view of the surface acoustic wave device shown in FIG. 2 taken along the line IV-IV.

FIG. 5 is a sectional view taken along line VV of the surface acoustic wave device shown in FIG. 2;

FIG. 6 is a plan view showing a conventional surface acoustic wave device.

FIG. 7 is a plan view showing a state of a semi-finished product of the surface acoustic wave device.

FIG. 8 is a sectional view taken along line VIII-VIII of the surface acoustic wave device shown in FIG. 7;

9 is a cross-sectional view of the surface acoustic wave device shown in FIG. 7 taken along the line IX-IX.

[Explanation of symbols]

 2a, 2b, 2c, 2d, 2e, 2f Terminal 3a, 3b, 3c, 3d, 3e, 3f, 15 Bonding pad part 5 Surface acoustic wave element 16 Groove 19a, 19b, 19c Wire

Claims (8)

[Claims] 1. A surface acoustic wave device, a terminal, a bonding pad portion electrically connected to the terminal, a bonding pad portion not electrically connected to the terminal, and the surface acoustic wave device being connected to the terminal. A surface acoustic wave device comprising: a wire that connects a bonding pad portion that is electrically connected to the terminal via a bonding pad portion that is not electrically connected. 2. A bonding pad electrically connected to a surface acoustic wave element, a terminal, a bonding pad portion electrically connected to the terminal, and a bonding pad portion not electrically connected to the terminal. A surface acoustic wave device, comprising: a wire connecting the terminal to the surface acoustic wave element. 3. The surface acoustic wave device according to claim 1, wherein an inductor is connected to the terminal. 4. The surface acoustic wave device according to claim 1, wherein the bonding pad portion is formed by printing. 5. The surface acoustic wave device according to claim 1, wherein each of the bonding pad portions is electrically insulated by a groove. 6. The bonding pad section which is not electrically connected to the terminal is formed in a plurality, and the bonding pad sections which are not electrically connected to the terminal are sequentially connected in series by wires. A surface acoustic wave device according to any one of claims 5 to 5. 7. The surface acoustic wave device according to claim 1, wherein the wire is one of an aluminum wire and a gold wire. 8. The wire has a diameter of 20 μm to 40 μm.
The surface acoustic wave device according to any one of claims 1 to 7, wherein