JPS58130613A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To obtain a surface acoustic wave device having a lamination structure in which plural elements are incorporated into a single device without increasing the area of the upper surface of a substrate, by laminating plural surface coustic wave elements via plates. CONSTITUTION:Reed screen type electrodes 6 are set on the upper surface of a substrate for surface acoustic wave elements 41, 42 and 43 respectively. A terminal 62 is soldered to a terminal extracting part 61 of the electrode 6. Laminating plates 51 and 52 of both-terminal supporting structure are set between the elements 41 and 42 as well as between 42 and 43 respectively. Thus an element lamination is formed. In this case, it is not necessary to use an equal material for the substrates of the elements 41-43. Otherwise the cut angle and propagating direction of the surface wave may be changed possibly among the substrates of the same material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated surface acoustic wave device having a plurality of surface acoustic wave elements within the device.

In general, a surface acoustic wave device has interdigital electrodes and a terminal extraction section installed on the upper surface of a substrate, the terminal extraction section is installed, and the terminal extraction section is electrically connected to an external terminal. Therefore, it has not been possible to incorporate a plurality of elements into one device without increasing the area of the top surface of the substrate.

An object of the present invention is to provide a surface acoustic wave device with a laminated structure in which a plurality of elements are incorporated into one device without increasing the area of the upper surface of the substrate. A detailed explanation will be given below based on the drawings.

FIG. 1 is an external perspective view of a laminated surface acoustic wave device of the present invention.

FIG. 2 shows a developed view of the first embodiment of the surface acoustic wave device according to the present invention. In the surface acoustic wave elements 41, 42 and 46 shown in FIG. 2, the interdigital electrodes 6 are installed above the substrate, and the terminals 62 are soldered to the terminal take-out portions 61 of the interdigital electrodes 6. C,
Between surface acoustic wave elements 41 and 42 and surface acoustic wave element 4
2 and 46, superposed plates 51 and 52, respectively.
An element stack is formed by installing the .

Here, the materials of the substrates of the surface acoustic wave elements 41, 42 and 46 do not necessarily have to be the same. For example, substrates made of different materials may be used, or even substrates made of the same material may have different cut angles and propagation directions of surface waves.

FIG. 3 shows a second embodiment of the surface acoustic wave device according to the present invention. Surface acoustic wave element 41 shown in FIG.
．． 42 and 46, the terminal take-out portions 61 of the interdigital electrodes are arranged on opposite sides in FIG.
And the terminal 62 is configured to be taken out only from one side.

FIG. 4 shows a third embodiment of the surface acoustic wave device according to the present invention. In FIG. 4, the top rIl of the substrate is
An electrode finger portion 66 of the interdigital electrode is installed at i11, and an electrode finger connecting portion 64 is installed on the side surface 12 of the substrate, and the terminal 62 is soldered (':tff) to the electrode finger connecting portion 64. When forming interdigital electrode fingers 66 by mask vapor deposition, when vapor deposition is performed on the upper surface 11 of the substrate and then on the side surface 12 of the substrate, the electrode finger connecting portion 6 of the interdigital electrode is formed.
The connection can be made more reliable by vapor-depositing 4 all the way to the upper surface 11 of the substrate. FIG. 5 shows a fourth embodiment of the surface acoustic wave device according to the present invention. In FIG. 5, electrode finger portions 66 of interdigital electrodes are provided on the upper surface 11 of the substrate.
is installed, and the electrode finger connection part is on the top surface 11 and side surface 12 of the board.
installed across both. 66 is the top surface 1 of the board
The electrode finger connection portions 65 installed at 1 indicate the electrode finger connection portions installed at the side surface 12 of the substrate. Electrode finger connection part 6
5, the terminal 62 is soldered to the terminal 62.

According to the configuration of the present invention as described above, a plurality of surface acoustic wave elements can be incorporated into the device. As a result, for example, by using one of a plurality of surface acoustic wave elements as a resonator and the other element as a filter, it is possible to configure a device with multiple functions. In addition, when the substrates of surface acoustic wave devices are made of different materials, or when substrates made of the same material are used and the cut angle and propagation direction are appropriately changed, the same mask can be used to separate each device. By configuring the structure, a device with multiple functions can be obtained.

Furthermore, the space forming effect of the stacked plates in this configuration makes it possible to form surface acoustic wave elements on both the front and back surfaces of the substrate. Therefore, the volumetric element density can be increased.

However, when forming surface acoustic wave elements on both the front and back surfaces by using the overlapping plates bi and bz in this configuration, if two elements are formed with approximately equal representation and connected in parallel, the electromechanical coupling coefficient can be reduced. Can be made larger.

On the other hand, when forming multiple surface acoustic wave elements, for example when changing the orientation with respect to the substrate on the front and back sides, or when forming thin films of different materials on one side, it is possible to form multiple elements with different temperature characteristics. By connecting elements in parallel, it is possible to adjust or flatten the temperature characteristics.

By providing a plurality of surface acoustic wave elements having interdigital electrodes on the upper surface of the substrate, and providing stacking plates 51 and 52 for stacking the surface acoustic wave elements on each other between the respective surface acoustic wave elements, the surface acoustic wave element can be fabricated. As a result of stacking the plates and forming a laminated structure, it is possible to obtain a surface acoustic wave device having multiple functions within the device.

In the laminated plate according to the present invention, the structure supporting both ends vibrates more strongly near the center of the surface acoustic wave element substrate than at both ends, and the structure supporting the center of the substrate vibrates more strongly than at both ends. This is because it adversely affects the frequency characteristics of the surface acoustic wave element. In the structure of the laminated plate according to the present invention, vibrations at both ends are extremely reduced by attaching surface acoustic wave absorbers to both ends, so supporting at both ends is effective in the laminated structure according to the present invention. Further, the flat plate portion of the stacked plate serves as a shield for the surface acoustic wave element located above or below.

In the above embodiment, the case where the number of elements of the surface acoustic wave device is three is shown, but the present invention can also be applied when the number of elements of the surface acoustic wave device is two or four or more. Included in the range. Furthermore, in the above embodiment, the surface wave absorber of the surface acoustic wave element is not shown for simplicity;
Even when this is attached, it is included in the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a surface acoustic wave element of the present invention, and FIGS. 2, 3, 4, and 5 are developed views of a surface acoustic wave device according to an embodiment of the present invention. 11...Top surface of the board 12...Side side 6 of the board
...Blind-shaped electrode 61.64.65...Terminal extraction part b1.52.
...Layering plate 62...Terminal Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5

Claims (3)

[Claims] (1) A surface acoustic wave device characterized in that a plurality of surface acoustic wave elements each having interdigital electrodes are stacked on a substrate with intervening plates interposed therebetween. (2) The surface acoustic wave device according to claim 1, wherein the overlapping plate has a structure that supports the surface acoustic wave element at both ends. (3) The surface acoustic wave device according to claim 1, wherein the surface acoustic wave elements are elements having different substrate materials, cut angles of the substrate materials, or surface propagation directions.