JP3196185B2 - Electronic component package and surface acoustic wave filter using this package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for electronic components used for a surface acoustic wave filter or the like using a surface acoustic wave propagating on a piezoelectric substrate, and a surface acoustic wave device using the package.

[0002]

2. Description of the Related Art The prior art will be described with reference to FIGS. FIG. 5 is a plan view of a conventional multi-stage connected resonator type surface acoustic wave filter, and FIG. 6 is a sectional view taken along the line ZZ of FIG. The piezoelectric substrate 7 is made of a thin plate of LiNbO ₃ and is processed into a rectangular shape. On the surface of the piezoelectric substrate 7, a cross finger electrode 7
1a, 72a and reflector electrodes 71b, 71c, 72
b and 72c are formed, and two pairs of resonator-type surface acoustic wave filters 7 each having two surface acoustic wave resonators provided in parallel are provided.
1 and 72. Ceramic package 1
Has a generally four-layer structure of a lower layer 1a, an intermediate layer 1b, an upper layer 1c, and a metal layer 1d, and is provided with electrode pads 81, 82, 83, 84, 85, 86 for leading electrodes to the outside. The piezoelectric substrate 7 on which electrodes are formed is housed in this package, and is electrically connected to the electrode pads by bonding wires. The interdigital electrodes inside the resonator-type surface acoustic wave filters 71 and 72 are commonly connected, and are led out to two opposite corners of the piezoelectric substrate by bus electrodes 73.
The electrode pads 83 and 86 are led out as input / output electrodes, the electrode pads 81 and 84 are led out as first ground electrodes, and the electrode pads 82 and 85 are led out as second ground electrodes. Have been. Finally, the metallic lid 6 and the metal layer 1d are hermetically sealed by seam welding.

[0003]

In such a surface acoustic wave resonator type filter, the first and second ground electrodes are usually connected in common and used as a filter without adding any other circuit elements. However, depending on the required passband characteristics of the filter, electric characteristics such as passband characteristics may be adjusted by adding a circuit element such as an inductor to the first ground electrode and grounding the first ground electrode. . In such a case,
Although it is conceivable to incorporate a chip inductor in the package, chip inductors generally do not support high frequencies such as surface acoustic waves, and even if they do, they are expensive or require additional storage space Had the disadvantage that In addition, electronic components that require other inductors also have problems such as an increase in the size of the package.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In an electronic component which may require an inductor, such as a multi-stage surface acoustic wave filter, the inductor can be used without lowering the Q value. It is another object of the present invention to provide a package for electronic components capable of coping with a high frequency and easily adjusting an inductance, and a surface acoustic wave filter using the package.

[0005]

In order to solve the above problems, a package for an electronic component according to the present invention has a plurality of chambers for accommodating electronic component elements and a separation band for separating each of the chambers. An inductor is formed in the separation band, and a plurality of electrode pads for electrically connecting to the electronic component element are provided inside the electronic component package, and the separation band includes a lower layer of the inductor. A plurality of lower layer line electrodes which are arranged substantially in parallel to form an electrode; a ceramic layer having a plurality of intermediate line electrodes which are electrically connected at both ends of the lower layer line electrodes and extending upward; Upper line electrodes electrically connecting the upper end of the intermediate line electrode extending from one end of the lower line electrode and the upper end of the intermediate line electrode extending from the other end of the adjacent lower line electrode. Is formed, it is characterized in that integrally formed an inductor having a coil-shaped conductor path as a core the ceramic layer in each of these line electrodes on the package. In order to improve the magnetic flux density, the ceramic layer serving as the core is preferably formed of a magnetic material.

A surface acoustic wave filter using the above-mentioned electronic component package has a plurality of surface acoustic wave devices having at least interdigital electrodes for exciting surface acoustic waves on the surface of a piezoelectric substrate, and a space between the surface acoustic wave devices. By forming an intervening and at least forming a separator that forms an inductor,
A package having a storage chamber for each surface acoustic wave element and having electrode pads for electrically connecting the surface acoustic wave elements to each other at several locations; and a surface acoustic wave filter obtained by hermetically sealing the package. And the separation band portion,
A lower ceramic layer, electrode pads for electrically connecting the surface acoustic wave elements to each other at several places on the upper surface of the lower ceramic layer, and a lower electrode of the inductor which is also provided on a part of the upper surface of the lower ceramic layer. A plurality of lower-layer line electrodes arranged substantially in parallel, an upper ceramic layer having a plurality of intermediate line electrodes extending upward and electrically connected to both ends of the lower-layer line electrodes, and one end of these lower-line electrodes And upper line electrodes electrically connecting the upper ends of the intermediate line electrodes extending from the other ends of the adjacent lower line electrodes, respectively, and the upper ceramic layer is formed by each of these line electrodes. An inductor of a separator having a coiled conductor path as a core is interposed between the plurality of surface acoustic wave elements and a ground electrode. It is characterized in that form.

[0007]

In the electronic component package, since the inductor formed by the conductor path (line electrode) of the coil is formed in the ceramic laminated portion by the ceramic lamination technology and the metallization technology, a relatively large area is allocated to the formation of the inductor. be able to. Therefore, the degree of freedom in designing the electrical characteristics of the inductor, such as the interval between the line electrodes and the number of turns, is large, and an inductor corresponding to a higher frequency can be formed. The package has a plurality of chambers for accommodating the electronic component elements and a separation band that divides each of the chambers.In the separation band, an inductor is formed. Together, electromagnetic isolation between rooms can be expected. In addition, the upper line electrode forming the inductor may be separately coated with a ceramic layer or the like, but it is necessary to short-circuit the upper line electrode in an exposed state or to cut the short-circuited upper line electrode in advance. Thereby, the adjustment of the inductance can be performed very easily.

When the electronic component package is applied to a surface acoustic wave filter, a housing for each surface acoustic wave element is formed by a separation band, and an inductor is formed in the separation band. Electromagnetic interruption between the chambers can be expected due to the presence of the electrodes and the like constituting the inductor. In addition, the passband characteristics can be adjusted by joining the electrodes constituting the surface acoustic wave filter and the respective electrode pads of the package, and short-circuiting or cutting off the upper line electrode constituting the inductor as necessary. Becomes easier.

[0009]

An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a surface acoustic wave filter using an electronic component package according to the present invention, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 is a sectional view taken along line YY of FIG. The package 1 made of ceramic such as alumina has a two-chamber separation structure,
It comprises a first chamber C1, a second chamber C2, and a separation band B separating these chambers. A step 11 is provided at the inner peripheral portion of the package and at an end in the width direction of the separation band portion B, and electrode pads 21, 22, 23, 24, 25, 2 are provided on a part of the step 11.
6, 27 and 28 are provided. A shield electrode 12 that is grounded is provided at the bottom of the package. The opening of the package is a metal frame (metal layer) made of Kovar
1d is joined by brazing. The step 1 of the separator
Above 1, inductors 41 and 42 are provided integrally with the package by ceramic lamination technology, and input / output electrodes of interdigital electrodes 31 a and 32 a on piezoelectric substrates 31 and 32, which are electronic component elements described later. It is arranged between the connected electrode pad 29 and the grounded electrode pads 22 and 26.

[0010] Such a ceramic package is manufactured in the following lamination order. On the upper part of the plate-shaped first ceramic layer 1a constituting the lower part of the package, a portion extending around the first ceramic layer 1a and also extending in the longitudinal direction at the center in the short direction (the above-described separation band portion). And a second ceramic layer 1b in the form of a frame which overlaps with the second ceramic layer 1b. A metallized layer corresponding to the above-mentioned electrode pad is provided on a part of the upper portion of the second ceramic layer 1b, and the electrode pad 22-2 corresponding to the above-mentioned separation band portion B is provided.
A plurality of narrow line-shaped metallized layers constituting the lower line electrodes 41a and 42a of the inductor are provided obliquely and at equal intervals between the electrodes 9 or between the electrode pads 26 and 29. A third ceramic layer 1c is provided above the metallized layer corresponding to the separation band. The third ceramic layer 1c is provided with a small through-hole at a portion corresponding to each end of the lower line electrode, and the electrode material is also sucked into this hole and fixed to the inner peripheral surface to thereby fix the intermediate line electrode. 41b and 42b are provided. This third
Of the intermediate line electrodes 41b, 42b
And the lower line electrodes 41a and 42a are electrically connected to each other. And an upper end of the intermediate line electrode extending from one end of the lower line electrode;
The narrow line-shaped upper line electrodes 41c and 42c electrically connecting the upper ends of the intermediate line electrodes extending from the other ends of the adjacent lower line electrodes, respectively, correspond to the third band corresponding to this separation band portion.
Are formed at equal intervals on the upper portion of the ceramic layer. In addition, a third ceramic layer 1 having a width smaller than the outer peripheral width of the second ceramic layer is formed on the outer peripheral portion of the second ceramic layer.
c is provided. The third ceramic layer constituting the outer periphery of the package and the third ceramic layer constituting the separation band portion of the package may be laminated in the same step, or may be laminated in different steps to obtain a material and a high material. It may be different. A peripheral metal frame 1d is brazed to the upper part of the third ceramic layer. By constructing the package in this manner, two electronic component element storage chambers separated by the separation band are created, and each line electrode is surrounded by a third ceramic layer as a core above the separation band. The inductor can be formed by a configuration in which is spirally extended.

The piezoelectric substrates 31, 32, which are electronic component elements, are made of a thin plate of LiNbO ₃ and are each processed into a rectangular shape. On the surfaces of these piezoelectric substrates 31, 32,
Each of the interdigital electrodes 31a and 32a and the reflector electrode 3
1b, 31c, 32b and 32c are formed. Each electrode on each piezoelectric substrate constitutes a resonator type surface acoustic wave filter in which two surface acoustic wave resonators are provided in parallel. The piezoelectric substrates 31 and 32 are installed in the respective storage chambers of the package, and the bottom of the package and the lower surface of the piezoelectric substrate are joined with a conductive bonding material. The electrode pad 28 and one end of the interdigital electrode 31a, the other end of the interdigital electrode 31a and the electrode pad 2
9, one end of the electrode pad 29 and one end of the interdigital electrode 32a,
The other end of the interdigital electrode 32a, the electrode pad 24, the reflector electrode 31b (reflector electrode 31c) and the electrode pad 21, and the reflector electrode 32c (reflector electrode 32b) and the electrode pad 25 are electrically connected by the bonding wire 5, respectively. Join. The electrode pads 28 and 24 are led out as input / output electrodes, and the electrode pads 21, 23, 25 and 27 are led out as ground electrodes. The electrode pad 2 connected from the electrode pad 29 via the inductor 41
2, or the electrode pad 26 connected via the inductor 42 is connected to the grounded electrode pad in the package (not shown) and is led out. The metallic lid 6 is hermetically joined to the metallic frame 1d by seam welding or the like.

Another embodiment is shown in the plan view of FIG. In addition,
The same numbers are used for the same structural parts as in the first embodiment. In this embodiment, the third line in which the intermediate line electrode is the core
The cutout portion formed on the side surface of the ceramic layer is extended, and a plurality of through holes are provided in a state of a green sheet before sintering, and by cutting this through hole portion, Notches can be provided. Upper line electrodes 41c, 42c constituting inductors 41, 42
Is partially or entirely short-circuited on the surface by the short-circuit line electrodes 41d and 42d. When adjusting the pass band characteristics, the common line electrodes are sequentially blown by a laser or the like, and the cutting may be stopped when the desired characteristics are obtained, which has an advantage that the electric characteristics can be adjusted more easily. I have. The present invention is not limited to the resonator type surface acoustic wave filter described in the above embodiment, but can be applied to other composite electronic components such as a monolithic crystal filter. Further, the electrode pattern of the resonator type surface acoustic wave filter and the wiring electrode pattern formed on the package are not limited to the above-described embodiment, and may be appropriately selected and designed according to desired electrical characteristics.

[0013]

According to the present invention, since an inductor formed by a conductor path (line electrode) of a coil is formed in a ceramic laminated portion by a ceramic laminating technique and a metallizing technique inside an electronic component package, a relatively large area of the inductor is formed. Can be devoted to Therefore, the interval between the line electrodes,
The degree of freedom in designing the electrical characteristics of the inductor, such as the number of turns, is large, and an inductor corresponding to a higher frequency can be formed. The package has a plurality of chambers for accommodating the electronic component elements and a separation band that divides each of the chambers.In the separation band, an inductor is formed. In addition, electromagnetic interruption can be performed between the respective rooms, so that deterioration of characteristics due to electromagnetic interference between electronic component elements can be prevented. In addition, the upper line electrode forming the inductor may be separately coated with a ceramic layer or the like, but it is necessary to short-circuit the upper line electrode in an exposed state or to cut the short-circuited upper line electrode in advance. Thereby, the adjustment of the inductance can be performed very easily.

When the electronic component package is applied to a surface acoustic wave filter, a housing for each surface acoustic wave element is formed by a separation band, and an inductor is formed in the separation band. Electromagnetic interruption between the chambers can be expected due to the presence of the electrodes and the like constituting the inductor. In addition, the passband characteristics can be adjusted by joining the electrodes constituting the surface acoustic wave filter and the respective electrode pads of the package, and short-circuiting or cutting off the upper line electrode constituting the inductor as necessary. Becomes easier. Therefore, it is possible to obtain a surface acoustic wave filter having excellent electric characteristics and easily adjusting the characteristics.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line YY of FIG. 1;

FIG. 4 is a plan view showing another embodiment.

FIG. 5 is a plan view showing a conventional example.

FIG. 6 is a sectional view taken along the line ZZ of FIG. 5;

[Explanation of symbols]

 1 Package 31, 32, 7 Piezoelectric substrate 41, 42 Inductor 41a, 42a Lower line electrode 41b, 42b Intermediate line electrode 41c, 42c Upper line electrode 41d, 42d Short-circuit line electrode

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H03H 9/145 H01F 27/00 H03H 9/25

Claims (2)

(57) [Claims] A plurality of chambers accommodating an electronic component element;
It has a separator that separates each chamber, and the separator has an
A package for an electronic component on which a plurality of electrode pads for electrically connecting to the electronic component element are provided inside the package for an electronic component, and a lower electrode of an inductor is provided on the separation band portion. A plurality of lower layer line electrodes arranged substantially in parallel with each other, both ends of these lower line electrodes are electrically connected to each other, and a ceramic layer having a plurality of intermediate line electrodes extending upward therein; An upper line electrode is formed to electrically connect an upper end of the intermediate line electrode extending from one end and an upper end of the intermediate line electrode extending from the other end of the adjacent lower line electrode. Wherein an inductor having a coil-shaped conductor path is integrally formed with the package. Di. 2. A plurality of surface acoustic wave elements having interdigital electrodes for exciting at least surface acoustic waves on a surface of a piezoelectric substrate, and a separation band portion interposed between these surface acoustic wave elements and at least forming an inductor is formed. By doing each bullet
A package having an electrode pad for electrically connecting the surface acoustic wave elements to each other at a plurality of places , and a surface acoustic wave filter obtained by hermetically sealing the package. The separation band portion includes a lower ceramic layer, electrode pads for electrically connecting the surface acoustic wave elements to each other at several places on the upper surface of the lower ceramic layer, and a part of the upper surface of the lower ceramic layer. A plurality of lower line electrodes arranged substantially in parallel to form a lower electrode of the inductor, and both ends of these lower line electrodes are electrically connected to each other, and an upper ceramic layer having a plurality of intermediate line electrodes extending upward; The upper end of the intermediate line electrode extending from one end of these lower line electrodes and the upper end of the intermediate line electrode extending from the other end of the adjacent lower line electrode. Upper line electrodes that are electrically connected to each other, and each of the line electrodes is connected to the plurality of surface acoustic wave elements and a ground electrode by using an inductor of a separator having a coiled conductor path with the upper ceramic layer as a core. A surface acoustic wave filter characterized by being configured to be interposed in a surface acoustic wave filter.