KR830000156B1 - Piezoelectric device - Google Patents

Abstract

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Description

Piezoelectric device

1 and 2 are perspective and side views, respectively, of a piezoelectric resonator of the prior art.

3 is a side view of a piezoelectric filter of the prior art made using a plurality of piezoelectric resonators shown in FIG.

4 is a graph showing the amplitude delay time characteristics of the prior art filter shown in FIG.

5 and 6 are front views of the front and rear surfaces of the piezoelectric resonator plate, respectively, which form part of the piezoelectric filter of the prior art shown in FIG.

7 is a side cross-sectional view of the piezoelectric resonator plate seen in FIGS. 5 and 6;

8 (a), 9 (a) and 10 (a) are front views of the primary, secondary and common terminal members used in the filter in FIG.

8 (b), 9 (b) and 10 (b) are cross-sectional views of terminal members as seen in 8 (a), 9 (a) and 10 (a), respectively.

11 is a side cross-sectional view of a three-terminal piezoelectric filter of the prior art in an assembled state.

12 is a graph showing the relationship between the contact pressure ratio and the change in any one of the insertion loss and the center frequency.

13 is a side view of a piezoelectric machine according to the first claim of the present invention.

FIG. 14 is a graph showing the relationship between the impedance and the frequency of the piezoelectric motor shown in FIG.

15 and 16 are side views of piezoelectric devices according to the secondary and tertiary claims, respectively, of the present invention.

FIG. 17 is a graph showing the relationship between the sizes of the respective contact protrusions used in the piezoelectric apparatus of FIG.

FIG. 18 is a graph showing the relationship between the anti-resonant frequency and the size of each contact projection used in the piezoelectric motor of FIG.

FIG. 19 is a graph showing the relationship between the resonance resistance and the size of each of the contact protrusions used in the piezoelectric motor of FIG.

FIG. 20 is a graph showing the relationship between the anti-resonance resistance and the size of the respective contact protrusions used in the piezoelectric motor of FIG.

21 and 22 are side cross-sectional views of piezoelectric elements according to the fourth and fifth claims of the present invention, respectively.

23 is a graph showing the frequency side force characteristics of the piezoelectric motor shown in FIG.

24 is a side view of a piezoelectric machine according to the sixth claim of the present invention.

FIG. 25 is a graph showing the relationship between the pressure change applied to the filter seen at 24 degrees and the change of the passband width in the two filters.

FIG. 26 is a graph showing the relationship between pressure and change applied to the filter of FIG. 24 and the insertion loss of the filter.

FIG. 27 is a graph showing the relationship between pressure change and resonance frequency of FIG.

FIG. 28 is a graph showing the relationship between the change in pressure of the filter of FIG. 24 and the anti-resonant frequency.

FIG. 29 is a graph showing the relationship between the pressure change of the filter of FIG. 24 and the resonance resistance. FIG.

30 is a graph showing the relationship between the change in pressure of the filter of FIG. 24 and the anti-resonance resistance.

FIG. 31 is a graph showing the amplitude delay time characteristics of the filter of FIG. 24. FIG.

32 (a) and (b), 33 (a) and (b), and 34 (a) and (b) are 8 (a) and (b) and 9 (a). And (b) and similar drawings to tenth (a) and (b), respectively, showing primary and secondary and common terminal members used in piezoelectric devices according to the seventh claim of the present invention.

35 is a plan view of the conductive elastic sheet used in the piezoelectric machine shown in FIG.

FIG. 36 is a plan view of a piezoelectric resonator plate assembly used in the apparatus shown in FIG.

FIG. 37 is a cross sectional view taken along X-X line in FIG. 36; FIG.

38 is a side cross-sectional view of a piezoelectric machine according to claim 7 in an assembled state.

FIG. 39 is a graph showing the relationship between the contact pressure ratio and insertion loss and center frequency of the apparatus of FIG.

FIG. 40 is a plan view showing a modified form of the primary and secondary terminal members seen in FIGS. 32 and 33;

41 is a plan view showing a modified form of the common terminal member shown in FIG.

42 is a plan view showing a more modified form of the common terminal member shown in FIG.

FIG. 43 is a view similar to FIG. 38, showing a piezoelectric motor using common terminal members of the mechanism shown in FIG.

The present invention relates generally to piezoelectric devices. More specifically, it relates to a piezoelectric filter using a piezoelectric resonator and at least one resonator.

It is well known to those skilled in the art that a piezoelectric resonator as a circuit element can produce a bandpass filter with low loss.

On the other hand, since the piezoelectric filter to which the present invention is related has been manufactured with at least one piezoelectric resonator, a reference to the piezoelectric resonator will be given first when examining the situation of the prior art. As shown in FIG. 1, which is a side view of the piezoelectric resonator, the piezoelectric resonator includes, for example, a primary piezoelectric resonator plate 1 and a secondary electrode layer 4 attached to the primary surfaces of the piezoelectric resonator plate 1, respectively. It is known that it is composed of the primary and secondary conductive terminal members (2) and (3) provided in the () and (5), and the tertiary conductive terminal member (6) provided in the common electrode layer (7). .

Although similar to the structure of the piezoelectric resonator, piezoelectric resonators having contact protrusions 2a and 3a which are fixed to or integrally formed with the primary and secondary terminal members 2 and 3, respectively, are also known. This type of piezoelectric resonator is indicated by (Y) of FIG. 2, in which the primary and secondary terminal members 2 and 3 are the nodes of vibration of the piezoelectric resonator plate 1. It is electrically connected to the primary and secondary electrode layers 4 and 5, respectively, via contact protrusions 2a and 3a which are in contact with each other in line with the node.

The piezoelectric resonator plate 1 is firmly supported on the primary and secondary terminal members 2 and 3, and the primary and secondary terminal members 2 and 3 are primary. And contact terminals 2a in close contact with the primary and secondary electrode layers 4 and 5 in order to ensure that all of the secondary electrode layers 4 are electrically connected to each other. ) And (3a) are made of a metallic material with sufficient elasticity to exert the pressure necessary to maintain the components of the piezoelectric resonator (Y) in one aggregate state. However, due to the special support mechanism and the limitations of the types of materials available, the prior art piezoelectric resonators (Y) have no room for improvement in how to prevent them from vibration and shock.

In order to make the piezoelectric machine have sufficient resistance to vibration or shock, it has been proposed to use an elastic polymerized compound such as that disclosed in Japanese Utility Model Publication No. 52-60278 published in 1977, for example, rubber. According to the above publication, the elastic polymer compound is used as a material for the projection which is conductive and is joined to the terminal member of the same component as shown in FIGS. 2A and 3A. Moreover, the coating of the conductor elastomeric compound on the metal terminal member is also disclosed.

Any of the above-mentioned piezoelectric resonators as shown in FIGS. 1 and 2, respectively, is called a two terminal piezoelectric resonator in the sense that the resonator has two terminals, while the Japanese patent was published in 1977. Japanese Patent Application Laid-Open Publication No. 52-10547 and Japanese Utility Model Publication Nos. 52-122631 and 52-122632 disclose a three-terminal piezoelectric resonator that can be advantageously used as a band pass filter. The three-terminal piezoelectric resonators are generally configured as shown in FIGS. 5 to 11.

5 to 11, the three-terminal piezoelectric filter of the prior art has the same center as the surrounding electrode layer 11, as shown in FIG. 1, and is electrically connected to the central electrode layer 12 that is electrically insulated. It is composed of a piezoelectric resonator plate 10 of a quadrangular shape having one surface attached or coated, and the opposite side of the piezoelectric resonator plate 10 is connected to the common ground electrode layer 13 as shown in FIG. It is attached or coated.

The resonator plate assembly having the piezoelectric resonator plate 10, electrode layers 11, 12, and 13 is as shown in the cross-sectional view of FIG.

Shown in FIG. 8 (a) is a single primary terminal member 14, a pair of conductive elastics protruding from the elongated terminal body 14c at right angles to the outside in the same direction and in parallel with each other. Tongues 14a and 14b, whose elastic tongues 14a and 14b maintain a predetermined predetermined distance corresponding to the spacing between the opposite portions of the surrounding electrode layer 11 and are spaced from each other. To form.

As shown in FIG. 8 (b), each of the elastic tongue pieces 14a and 14b is as shown in FIG. 11 and will be described later, but in the assembled state, as shown in FIG. It is bent to provide the contact portions 15a and 15b in contact with the regions P1 and P2 on the opposite side of the electrode layer 12, respectively.

9 (a), the secondary terminal member 16 is composed of an elongated terminal body 16a and a contact plate portion 16b protruding outwardly and at right angles from the terminal body 16a. The contact plate portion 16b has a contact protrusion 17 that is fixed or integrally formed. When the contact plate portion 16b is in the assembled state as shown in Fig. 11, the contact end portion 16b is in a space composed of the elastic tongue pieces 14a, 14b and the terminal body 14c. The primary terminal member 14 can be placed in an electrically insulated state, and the central electrode layer 12 can be covered by the contact protrusion 17 which electrically connects the central electrode layer 12.

Also shown in FIG. 10 (a) is a common terminal member 18, which is composed of long and short conducting bars 18a and 18b, which are almost cross-shaped at right angles to each other. As shown in Fig. 10 (b), there is a contact protrusion 18c which is at the intersection of the two rods 18a and 18b and protrudes outward from the intersection.

As shown in FIG. 10 (b), the common terminal member 18 allows the common terminal member 18 to be elastic against pressure that can be applied in a direction opposite to the direction of the projection of the contact projection 18c. The terminal member 18 is bent into a substantially spherical shape with the contact protrusion 18c at the spherical vertex position.

These components referred to in FIGS. 5-10 are assembled together in the manner shown in FIG. 11 and consist of a single casing consisting of the same casing halves 19a and 19b which are generally container-shaped. 19) It is put in.

More specifically, the resonator plate assembly comprising the piezoelectric resonator plate 10 and the electrode layers 11, 12, 13 will have its terminal member 18 placed in the casing 19 together with the other components. The terminal members 14, 16 and 18 in the manner in which the resonator plate assembly acts through the contact protrusion 18c in contact with the electrode electrode layer 13 when the terminal is exerted. It is supported in place in the casing (19) by using.

The contact protrusion 17 in the terminal member 16 maintains intimate connection with the center electrode layer 12. Thus, the resonator plate assembly is firmly fitted in the position between the contact protrusions 18c and 17 in the casing 19 by the action of the elasticity exerted by the terminal member 18.

At this time, the contact portions 11 and 15a of the elastic tongues 14a and 14b of the terminal member 14 are surrounded by the action of elasticity exerted by the elastic tongues 14a and 14b. The contact portions P1 and P2 of the opposite side are maintained in contact with each other. It should be noted that the elasticity exerted by the elastic tongues 14a and 14b in order to bring the contacts P1 and P2 on the opposite side of the electrode layer 11 surrounding the contacts 15a and 15b into contact with each other. It is less than the elasticity exerted by the terminal member 18 to push the resonator plate assembly toward the contact projection 17 in the terminal member 16.

의 범위 내에 있도록 선택한다.More specifically, in the prior art filter having the structure shown in detail in FIG. 11, the elasticity exerted by the elastic tongues 14a and 14q is determined by the elasticity of the terminal member 18.

Choose to be within the range of.

The reason for this is that the contacts P1 and P2 correspond to the loops of the mechanical vibration of the piezoelectric resonator plate 10, so that the contacts P1 and P2 are located in the terminal member 14 ( The mode of vibration that occurs in the piezoelectric vacuum plate 10 when it is strongly pressurized by 15a) and 15b, respectively, is a graph showing the shift of the fluctuating center frequency of insertion loss. This is because it is adversely affected to the extent that it turns into a separate shape. It should be noted that in the graph of FIG. 12, the term “contact pressure ratio” refers to the contact pressure of the contact protrusion 18 against the contact electrode portion 17 in alignment with the contact protrusion 17. The ratio of the contact pressures of the contact portions 15a and 15b to the contact portions P1 and P2 compared.

In addition, a ladder-type filter, which is composed of a plurality of piezoelectric resonators using respective vibration modes or radial vibration modes, has a structure as shown in FIG. An example is shown in FIG. Referring to FIG. 3 of the annexed drawing, the ladder filter of the prior art is composed of, for example, several piezoelectric resonators I, II, III, IV and V of the first to fifth order, each of which is shown in FIG. It has a structure as shown.

Among these piezoelectric resonators, piezoelectric resonators I, III and V are series resonant elements, piezoelectric resonators II and IV are parallel resonant elements, and these piezoelectric resonators I to V respectively have parallel resonant elements between two adjacent series resonant elements. It is arranged to be nestled. In the ladder filter of the prior art shown in FIG. 3, the contact protrusions 2a and 3a of the respective terminal members 2 and 3 with respect to the piezoelectric resonator are combined with the node of the vibration of the piezoelectric resonance plate. At each position, the contact surface is maintained in contact with the combined surfaces of the corresponding piezoelectric resonator, and various components of the filter are pressurized by using any of the well-known spring elements, for example, a pressure of 250 to 300 / cm 2. It is compressed together by adding.

The terminal members 2 and 3 of the primary and fifth resonators I and V respectively serve as input and output terminals, respectively, and the terminal members of the primary and tertiary resonators I and III, respectively. (3) and (2) are connected to each other using the bridge elements 6a, and the terminal members 3 and (2) of the tertiary and fifth order resonators III and V, respectively, use the bridge elements 6b. And the electrically insulating sheets 7 and 8 are connected between the terminal members 3 and 2 of the secondary and tertiary resonators II and III, respectively. It is situated between the terminal members 3 and 2 of the 4th and 5th resonators and IV, respectively. In use, the terminal members 3 of the 2nd and 4th resonators II and IV are respectively assured.

The sorting filter and the group delay time characteristic of the ladder filter of the prior art shown in FIG. 3 are shown in the graph of FIG. 4, and the improvement of the ladder filter as described above is to suppress P hase distortion. The group time delay characteristics have long been desired. It is to reduce the mechanical goodness (Q) of the conventional piezoelectric resonator to improve the group time delay characteristic from the number 10 to the number 100. However, conventional methods for improving the group time delay characteristics are known to present various difficulties.

In particular, the proportion of the mixed material must be adjusted according to the particular value of the mechanical goodness (Q) to be selected, so that filters with desired temperature characteristics (PC), electrical physical coupling coefficients (K) and dielectric constants are no longer present. You can't get it without difficulty. Moreover, when the mechanical goodness Q decreases, the frequency constant Fol correspondingly decreases.

For example, if a filter using a resonator with a relatively low mechanical goodness (Q) is incorporated in the casing as long as the filter is incorporated with resonators of about 1000 mechanical goodness (Q), the resistance to impact is Due to the small size of the resonators used, there is a tendency for the vibrations to be significantly attenuated and to be insufficient.

One of the separations common to all the prior art piezoelectric resonators discussed above is relatively low resistance to vibration and shock. For example, since the terminal members are in direct contact with the electrode layer or the like, when the resonator is subjected to an external impact, the electrode layers are likely to be damaged, eg, fall off, by the attached terminal members. This phenomenon is particularly observed in the resonator having the structure shown in FIGS. 2, 3 and 11.

For this reason, the electrode collision in the piezoelectric resonator of the prior art should have a relatively large thickness in view of any mechanical damage caused by the direct contact of the terminal member to its attached electrode collision. Considering that each electrode layer is made of a precious metal such as gold, silver, or platinum, the use of a relatively large thickness of the electrode layer becomes expensive for piezoelectric resonators.

In the structure of the prior art piezoelectric resonators of FIGS. 2, 3 and 11, care must be taken to accurately place each terminal member in the contact projections and the piezoelectric resonant plates arranged in line with the vibrating nodes of the piezoelectric resonator plate.

In the piezoelectric filter of the prior art shown in FIG. 11, in particular, the adjustment of the elasticity exerted by the elastic tongues 14a and 14b of the terminal member 14 involves difficulty. For example, when the elasticity exerted by the terminal member 14 is moderately improved, the piezoelectric filter exhibits smooth performance characteristics, but the resistance to vibration and / or shock is lowered. On the contrary, when the elasticity exerted by the terminal member 14 is high, the resistance to vibration and maneuver is improved, but the filter does not exhibit smooth performance characteristics. In addition thereto, the piezoelectric filter and the design and manufacture of the prior art are complicated enough to result in an increase in the manufacturing cost.

As can be readily seen from the above review, any of the piezoelectric filters of the prior art is expensive, relatively unstable in performance, large in size, and requires an increase in manufacturing costs and complicated manufacturing processes. On the other hand, they face the fierce competition of some manufacturers of piezoelectric resonators, and thus have to focus their efforts on minimizing manufacturing costs while rewriting their performance.

In this respect, it has long been desired to provide a piezoelectric resonator that is simple in structure, excellent in performance, and whose manufacture can be automated. According to the present invention these disadvantages and inconveniences associated with prior art piezoelectric devices have primary and secondary surfaces opposite to each other, at least one of which each of the primary and secondary surfaces is formed thereon. One piezoelectric resonant plate having an electrode layer of the same number as the number of electrode layers, and one of the conductive terminal members and its terminal members contacting each electrode layer on the primary and secondary surfaces of the piezoelectric resonance plate. And one improved piezoelectric device composed of at least one electrically conductive elastic sandwich sandwiched between the corresponding electrode layer, which is connected to the terminal member thereof, can be substantially eliminated.

The present invention is characterized by the use of a conductive elastic sheet composed essentially of an isotropic conductive plastic sheet. In the above term, the term isotropically conductive plastic sheet refers to a conductive elastic having a characteristic of showing electrical conductivity only in a certain direction through the thickness of the elastic sheet when compared to a normal conductive elastic sheet showing electrical conductivity in all directions in the present description. It should be understood as meaning sheet. The oriented conductive plastic sheet has been developed almost recently, and only a few years have it been commercialized and used. The oriented conductive plastic sheet is generally a conductive material, for example metal particles, carbon particles or particles dispersed in a constant arrangement and orientation, such that several insulated and parallel electrical circuits in the thickness direction of the plastic sheet can be defined. It is a sheet of the silicon rubber containing the fiber containing metal, etc. The oriented conductive plastic sheet is currently commercialized and used in two kinds. One of them is an anisotropic conductive plastic sheet that can only exhibit conductivity in a certain direction across its thickness, and the other is the same characteristics as the anisotropic conductive plastic sheet. It is a piezoelectrically conductive plastic sheet which needs to respond to a certain pressure in order to make it conductive through the thickness of the sheet.

In the present invention, any ordinary conductive elastic sheet as well as the directional conductive plastic sheet can be advantageously used. Therefore, for the purposes of the present invention and to distinguish the ordinary conductive elastic sheet from the oriented conductive plastic sheet, both the ordinary conductive elastic sheet and the oriented conductive plastic sheet are interpreted as falling into the class of the conductive elastic sheet.

According to the present invention, any one of the totally conductive elastic sheet and the directional conductive plastic sheet can be used as long as the two terminal piezoelectric resonator is included. However, according to the present invention, it is recommended to use a directional conductive plastic sheet when one of the opposing surfaces of the piezoelectric resonator plate forming a part of the piezoelectric member has a plurality of electrically insulated electrode layers in which a corresponding number of terminal members are remaining. have.

In this case, the directional conductive plastic sheet may not be used in the same number as the number of electrode layers on one side of the piezoelectric resonant plate. However, due to the unique conductive properties of the oriented conductive plastic sheet, even if a single oriented conductive plastic sheet is placed between one terminal member and one electrode layer on one side of the piezoelectric resonant plate, any undesirable shortcircuiting may occur. It does not occur between every two electrode layers on one side of the piezoelectric resonant plate.

In any case, various advantages can be recognized because of the use of the conductive elastic sheet according to the present invention. For example, since the conductive elastic sheet is not only conductive, but also elastic, the conductive elastic sheet can absorb any impact or impact applied to the piezoelectric device constituting the present invention without substantially being transmitted to the piezoelectric resonant plate. have.

Therefore, in view of the elasticity of the conductive elastic sheet used in the present invention, not only the piezoelectric resonator plate supported at a firm and stable position between the terminals, but also the elasticity of the conductive elastic sheet may be used to It is effective in absorbing any possible error in the alignment, and thus substantially eliminates the problems associated with the exact alignment required in piezoelectric devices of the prior art.

Furthermore, as there is no direct contact between the terminal member or contact protrusion and its secondary electrode layer as required by prior art piezoelectric devices, there is no possibility of damaging the electrode layers.

This means that the piezoelectric constituting the present invention is not only extremely resistant to vibration and shock, but also durable. The use of conductive elastic sheets allows the use of relatively small thicknesses of electrodes without causing damage to the electrode layers, and therefore the piezoelectric elements constituting the present invention can be manufactured at a significantly reduced cost.

Furthermore, since the conductive elastic sheet used according to the present invention is adapted to be in place only during the manufacture of the piezoelectric machine, the manufacturing of the piezoelectric machine constituting the present invention can be easily performed without requiring any complicated process, and also relatively high productivity. Can be automated.

Above all, the present invention is effective in providing a piezoelectric machine capable of exhibiting an improved shape factor without substantially impairing its properties.

Other objects and features of the present invention will be described in detail with reference to the accompanying drawings.

Before proceeding with the description of the present invention, it is noted that parts of the same type are designated by the same reference numerals throughout the drawings. It should be noted that various configurations of the present invention are described separately under separate headings in order to improve the understanding of the present invention.

Example 1 Fig. 13 to Fig. 14

Referring to FIG. 13, one piezoelectric element shown therein is a two terminal piezoelectric resonator that can be used as a filter.

The two terminal piezoelectric resonators shown in FIG. 13 have the same structure as shown in FIG. 1 but between the primary terminal member 2 and the primary electrode layer 4 and between the secondary terminal member 3 and the secondary electrode layer ( 5) and primary and secondary conductive elastic sheets 20 and 21 respectively positioned between them. Each of the conductive elastic sheets 20 and 21 may be a total conductive elastic sheet or a directional conductive conductive plastic sheet. When the totally conductive elastic sheet was used for each of the primary and secondary conductive elastic sites 20 and 21, the piezoelectric element shown in FIG. 11 is at a constant frequency as indicated by the chain lines in the graph of FIG. Impedance is shown. However, when the directional conductive plastic sheet is used for each of the primary and secondary conductive elastic sheets 20 and 21, the piezoelectric device shown in FIG. 13 has a dotted line representing the impedance of the preceding piezoelectric device shown in FIG. And 14, compared with the chain line representing the impedance of the piezoelectric device having the terminal members directly implanted with the corresponding electrode layers disposed on the opposite sides of the piezoelectric resonant plate except for the contact protrusion of FIG. The impedance at a constant frequency is shown as indicated by the solid line in the graph of the figure. It should be noted that the number of used conductive elastic sheets of the resonator shown in FIG. 13 is shown as two as described, but the number need not be limited, and the primary and secondary conductive elastic sheets 20 and 21 are shown. Any of these may be proposed.

EXAMPLE 2 and 3-FIGS. 15-20

The piezoelectric device, which can be seen in any of FIGS. 15 and 16, is a two terminal piezoelectric resonator that can be used as a filter.

The two-terminal resonator shown in FIG. 15 has a structure similar to that shown in FIG. 2 but between the primary terminal member 2 and the primary electrode layer 4 and the secondary terminal 3 as in the configuration shown in FIG. ) And primary and secondary conductive elastic sheets 20 and 21 respectively positioned between the secondary electrode die 5 and the secondary electrode die 5.

However, the contact of the primary and secondary terminal members 2 and 3 to the primary and secondary electrode layers 4 and 5 through the conductive elastic sheets 20 and 21 is a conductive contact protrusion ( 2a) and 3a), respectively.

In the configuration shown in FIG. 15, the conductive elastic sheets 20 and 21 appear to be held flat with respect to the respective electrode layers 4 and 5, and the attached contact protrusions 2a and 3a are attached. It is supported by being seated together with the piezoelectric resonator plate 1 by using primary and secondary terminal members 2 and 3 which respectively apply elasticity thereto.

However, the conductive elastic sheets 20 and 21 may not always be held flat with respect to the electrode layers 4 and 5 as shown in FIG. 16, and the respective electrode layers 4 and ( They may bend along with their perimeter, which separates them from 5). This is the piezoelectric resonator plate 1 through the accessory contact protrusions 2a and 3a than those required to keep the conductive elastic sheets 20 and 21 flat against the electrode layers 4 and 5. This can be achieved by applying more resilience to the terminal members 2 and 3 for the reason that the conductive elastic sheets 20 and 21 have its flexibility when a relatively large external pressure is applied thereto. This is because they have common characteristics as long as they tend to bend.

As in the case of the configuration shown in Fig. 13, the number of conductive elastic sheets used in any of the configurations shown in Figs. 15 and 16 is not limited to two and none of them can be excluded. Preferably, the prior art has a structure as shown in FIG. 2 where the contact surfaces of the connecting protrusions 2a and 3a are small with respect to the electrode layers 4 and 5, respectively, through the attached conductive elastic sheets 20 and 21, respectively. Is wider than that of the resonator.

If each of the contact protrusions 2a and 3a in the prior art blank of FIG. 2 has a relatively large contact surface area for the electrode layer, the change in the resonant frequency anti-resonant frequency resonance resistance and anti-resonance resistance is undesirable. Tend to appear.

However, in the present invention, because of the use of the conductive elastic sheets 20 and 21, the contact protrusions 2a and 3a are connected to the corresponding electrode layers 4 and 5 through the conductive elastic sheets 20 and 21. Can have a relatively large contact surface area. The advantages of the present invention resulting from the use of relatively large contact surface areas of the respective contact protrusions for the electrode layer can be readily recognized from the graphs respectively shown in FIGS. 17 to 20.

The term “applied pressure” in the graph shown in FIGS. 17 to 20 refers to various components that are related in a direction perpendicular to the plane of one of the primary and secondary surfaces of the piezoelectric resonator plate 1. Refers to the pressure exerted from the outside of the resonator to press together, the diameter of the contact area of each contact projection with respect to the electrode layer is indicated on the axis of the coordinates.

The data shown in the graphs of FIGS. 17 to 20 can be applied when the piezoelectric resonator plate has a surface area of 20.25 m 2. It can be easily seen from the graphs of FIGS. 17 to 20 that changes in resonance frequency, anti-resonant frequency, resonance resistance and anti-resonance resistance occurring in the piezoelectric resonator of the present invention are reduced to a minimum.

Example 4 and 5-21 to 23

In either of the above configurations, both or each of the conductive elastic sheets 20 and 21 may be expanded conductive elastic sheets or isotropic conductive conductive plastic sheets, while the structure shown in any of FIGS. 21 and 22. All or each of the conductive elastic sheets used in the piezoelectric resonators of should be isotropic conductive plastic sheets for reasons as will be apparent from the description which follows.

First, referring to FIG. 21, the illustrated piezoelectric device is a three-terminal piezoelectric filter, which is substantially the same in structure as the apparatus shown in FIG. However, the device shown in FIG. 21 is different from that shown in FIG. 15, and the centers of the secondary electrode layers shown in FIG. 15 at 5 degrees are divided into ring-shaped electrode portions 5a and 5b, correspondingly. The secondary terminal member indicated by 3 in FIG. 15 is divided into a center and ring-shaped terminal elements 3b and 3c.

More specifically, the center electrode portion 5a and the ring electrode portion 5b are electrically insulated from each other, and the ring electrode portion 5b surrounds the center electrode portion 5a concentrically therewith. These electrode portions 5a and 5b are oriented conductive elastic sheets of the same size as the surface area of the secondary surface on the piezoelectric resonator plate 1 to which the center and ring-shaped electrode portions 5a and 5b are attached or coated. It is connected to each terminal element 3b and 3c via 21.

In detail, the terminal elements 3b have a single connecting projection 3d, and the terminal elements 3c having the same shape as the shape of the ring-shaped electrode portion 5b are spaced apart from each other at the same interval as possible. It has a some contact protrusion part 3e.

In the assembled state to the three-terminal piezoelectric filter, the contact protrusions 3d and 3e come into close contact with the center and the ring electrode portions 5a and 5b through the isotropic conductive elastic plastic 21. The isotropic conductive elastic plastic sheet 21 is in contact with the central electrode portion 5a, on the one hand with the ring-shaped electrode portion 5b, and on the other hand with sufficient contact with the terminal element 3b and the terminal element 3c. Although sized, the electric circuit is established only between the center electrode portion 5a and the terminal element 3b or only for the ring-shaped electrode portion 5b and its terminal element 3c.

This is due to the unique conductivity of the isotropic conductive elastic plastic sheet which exhibits conductivity only in the direction transverse to the thickness of the plastic sheet.

It should be noted that the conductive elastic sheet 20 which is opposite to the isotropic conductive elastic plastic sheet 21 may be a whole conductive elastic sheet, or may be an isotropic conductive elastic plastic sheet.

In the configuration shown in FIG. 22, the conductive elastic sheet 20 is excluded. This is the only difference between what we see in Figure 21 and what we see in Figure 22. And as can be easily understood from the graph shown in FIG. 23, the piezoelectric resonator shown in FIG. 22 exhibits an excellent shape factor as shown by a solid line when compared to that of the piezoelectric resonator of the prior art indicated by a dotted line. have.

In any of the configurations shown in Figs. 21 and 22, the various contact protrusions 2a, 3d, and 3e are not always necessary. Therefore may be excluded

Example 6 FIGS. 24 to 31

Fig. 24 shows a ladder filter which can exhibit improved group delay time characteristics.

The ladder filter shown in FIG. 24 is composed of a plurality of piezoelectric resonators I. II, III, IV and V, for example, first to fifth order, each of which has the structure shown in FIG. The piezoelectric resonators I to V are arranged in a face-to-face relationship with each other and connected in the same manner as shown in FIG.

The arrangement illustrated in FIG. 24 does not require the provision of such conductive projections as required in the prior art arrangements shown in FIG. It can be excluded as shown by the secondary terminal 3 of any of the resonators I and III or the primary terminal member 2 of any of the secondary and quaternary resonators II and IV.

As in the case of the filter shown in FIG. 3, the primary resonator I and the primary terminal member 2 and the secondary terminal 3 of the fifth resonator V are used as input and output terminals, respectively. The secondary terminal members 3 of the resonators II and IV are fitted to be as-as.

In practice, the assembly shown in FIG. 24 is in a casing and is subjected to a relatively large value, eg 600 g r / cm 2, which serves to compress the resonators I through V together. This pressure is exerted by at least one spring element whose casing is located between the wall and any one of the primary terminal members 2 of the primary resonator I, and the secondary terminal member 3 of the fifth resonator V It bears against the opposite wall of the casing.

No substantial change in resonant and antiresonant frequency occurs when the applied pressure is increased to a value greater than that required in the prior art filter of FIG.

However, the resonance resistance and the anti-resonance resistance increase and decrease, respectively, with the mechanical good quality Q substantially reduced.

FIG. 25 shows the relationship between the change in pressure applied and the change in pass band.

Figure 26 shows the relationship between the change in pressure applied and the insertion loss.

27 shows the relationship between the change in applied pressure and the resonance frequency.

28 shows the relationship between the change in applied pressure and the anti-resonance frequency. Figure 29 shows the relationship between the change in pressure applied and the resonance resistance.

30 shows the resistance between the change in pressure applied and the anti-resonance.

It should be noted that in any of the graphs shown in FIGS. 27 to 30, the solid line represents the value obtained with the conductive elastic sheets 20 and 21, respectively, in a ring-shaped filter, while the dotted line represents the conductivity. Each of the elastic sheets 20 and 21 represents a graph obtained with a filter having a square shape.

As can be easily understood from the graphs of Figs. 25 to 30, by appropriately selecting the amount of pressure to be applied, the group delay time characteristic of the filter of the present invention can be improved.

In detail, in doing so, the desired group delay characteristics can be easily achieved.

For example, the mechanical goodness (Q) of the filter, assembled according to the invention and compressed together with the resonators I to V and pressurization, as compared to a prior art filter with a mechanical goodness (Q) of 1000 is about One hundred reductions were found.

FIG. 31 shows the group delay time characteristic of the selective leisure characteristics of the ladder filter having the structure shown in FIG.

It should be noted that any of the conductive elastic sheets 20 and 21 may be of any desired shape, for example squares, rings, squares, hexagons, octagons, ovals, or any other desired size. Furthermore, the conductive elastic sheets 20 and 21 of the resonators or respective rotors may be of different shapes, or of different sizes. In addition, each of the resonators used in the configuration of FIG. 24 may not always be limited to two, and the number of elastic sheets 20 and 21 of the resonator may be one.

At least one of its constituent resonators I through V, which includes a ladder filter as shown in FIG. 24, may have at least one conductive elastic sheet.

According to the configuration shown in Fig. 24, the following advantages can be further recognized.

Moreover, the ladder filter of the prior art of FIG. 3 is prone to change in performance characteristics, especially when the filter itself is impacted or dropped, at a decay rate of -90 to -100 dB.

The performance curves of the high and low frequency components of the frequency at which maximum attenuation is achieved, as do the ladder filters of the prior art, show considerable waves.

In addition, when the ladder filter of the prior art exhibits a maximum attenuation of -80 to -90 dB, the ladder filter of the present invention shows a maximum attenuation of about -120 dB with a performance curve that does not cause a wave.

Considering the resistance to impact, the present invention can stabilize its performance up to at least 100 cycles of an application impact when the filter of the prior art of FIG. 3 tolerates 20 cycles of the application impact of one impact. This means that the filter according to the configuration shown in FIG. 24 does not cause any possible vibration or shock noise generation that it may receive during handling or transport in the normal way. Moreover, the filter of the present invention has shown a change in the suppressed criterion in the passband width in the range of 0-0.2 dB when compared to the change in the reference in the passband width occurring at 0.5-1.0 dB in the prior art filter.

Furthermore, it should be noted that instead of using the respective vacuum chambers having the structure shown in FIG. 13, the vacuums having the structure shown in FIG. 15 can be used for the ladder filter.

Example 7 FIGS. 32 to 39

The piezoelectric device shown well in FIG. 38 is a three-terminal piezoelectric filter similar to that shown in FIGS.

32 to 34, the common terminal member 18 used in the filter of FIG. 38 is identical in structure to that used in the prior art filter of FIG. The primary and secondary terminal members 14 and 16 are different from the primary and secondary terminal members 14 and 16 seen in FIGS. 8 and 9, respectively, and used in the present invention therein. The terminal member 14 has one phase of flat tongues 14a and 14b, and at the same time the terminal member 16 of the present invention has a contact projection as required by the terminal member 16 used in the filter of the prior art. Don't have In addition, the terminal members 14, 16, and 18 used in the present invention may be made of any conductive metal material having no elasticity.

As shown in FIG. 35, an area corresponding to the width of the square center electrode layer 12 is, for example, a substantially square isotropic conductive elastic having a length corresponding to the width of the square piezoelectric resonator 10. Plastic sheet 22. As shown in FIGS. 36 and 37, the isotropic conductive elastic plaster sheet 22 is assembled with tongues 14a 'and 14b' of the terminal member 14 as shown in FIG. Is placed on the piezoelectric resonator 10 so as to cover opposite portions of the central electrode layer 12 and the ring-shaped electrode layer 11 where it is electrically connected to the ring-shaped electrode layer 11 through an isotropic conductive elastic plastic sheet 22 when in Lose.

Due to the use of the isotropic conductive conductive plastic sheet 22 which exhibits its conductivity only in the thickness direction of the plastic sheet 22, the ring-shaped electrode layer 11 is formed by using opposite ends of the isotropic conductive conductive plastic sheet 22. The primary terminal member 14 is electrically connected only through the 14a 'and 14b', and the center electrode layer 12 is connected to the plastic sheet 22 using a substantial middle portion thereof. Only the secondary terminal member 16 is electrically connected via the.

However, it should be noted that the isotropic conductive elastic plastic sheet 22 is large enough to be placed between the transverse layer portion of the ring-shaped electrode layer 11 and the elongated terminal body 16a of the secondary terminal member 16. An electrical short may occur between the ring electrode layer 11 and the center electrode layer 12.

Referring to FIG. 38, the assembly shown in FIGS. 36 and 37 is encased in a casing 19 together with a common terminal member 18. As shown in FIG. In this assembled state, as shown in FIG. 38, in the assembly shown in FIGS. 36 and 37, the primary and secondary terminal members 14 are in contact with the floor on the casing half 19a, and at the same time, the common terminal members. (14) lies in the space made between the as-as electrode layer 14 and the casing half 19a, the common terminal member 18 being in line with the center electrode layer 12, as-as electrode layer 13 Is placed in the casing 19 in such a way as to resiliently engage the assemblies of FIGS. 3-6 and 37 through contacting portions 18c for electrical connection.

범위내에 있고, 중심주파수의 변화는 선행기술의 필터에서 일어나는 중심주파수의 변화량의

의 범위내에 있다.In the piezoelectric filter according to the configuration of the present invention described with reference to FIGS. 32 to 28, the piezoelectric resonator plate 10 may be easily seen from a graph shown in FIG. 39 similar to that shown in FIG. Even if the contact pressures of tongue tongues 14a 'and 14b' are increased to a value higher than the surface of prior art filters of the same kind, the insertion loss or center frequency does not substantially change, no matter how they change The change in loss is due to the amount of change in the center frequency occurring in the filter of the prior art.

In the range, the change in the center frequency is the amount of change in the center frequency occurring in the filter of the prior art.

Is in the range of.

In the preceding description, the primary and secondary terminal members 14 and 16 have been described as being composed of separate members and have been shown in the figures. However, both refer to FIG. 40 and may be assembled into a single component to be described now.

One terminal assembly shown in FIG. 40 is composed of an electrical insulating plate 23 having a square shape, and one surface thereof has a substantially primary U-layer 23a and an electrode leg 23c having a substantially U-shaped appearance. The second electrode layer 23b is formed into an L-shaped shape, and the formation of these electrode layers 23a, 23b and 23c on the surface of the insulating plate 23 can be performed by any known electrical circuit or printing technique. This is done using.

The terminal assembly consists of primary and secondary terminal blocks 24 and 25. The primary terminal block 24 has one foot end joined to the primary electrode layer 23a, and the secondary terminal block 25 has one end joined to one end of the free end of the electrode leg 23c. The primary and secondary terminal blocks 24 and 25 extend outward from the printed circuit board 23 in parallel with each other.

Note that the combination of the primary electrode layer 23a and the primary terminal block 24 and the combination of the secondary electrode layer 23b and the secondary terminal block 25 are respectively shown in FIGS. 32 and 33, respectively. As a common terminal member, which is desired for use in connection with the terminal assembly shown in FIG. 40, which is loaded in the function of the primary terminal members 14 and 16, it is formed by the electrode layer 26 on one side thereof. As shown in FIG. 41, it has the form of the substantially square electrode printed board 26 which has the one terminal block 27 by which Han group ends are joined to the electrode layer 26a.

Alternatively, the common terminal member may consist of a flat electrode plate member 28 having a substantially square body portion 28a and a leg 28b as shown in FIG.

One complete piezoelectric filter using the common terminal member of the structure shown in FIG. 42 is shown in FIG.

When a common terminal member composed of flat conductive members 28 is used as shown in FIG. 43, the use of the conductive elastic sheet between the as-as electrode layer 13 and the common terminal member 28 is shown in FIG. It is taken as shown by 22a. In this case, the conductive elastic sheet 22a may be an overall conductive elastic sheet or may be an isotropic conductive conductive plastic sheet.

It should be noted that one conductive elastic sheet similar to the elastic sheet 22a shown in FIG. 43 may be used, even in the structure shown in FIG. 38, and in this case, it is the as-electrode layer 13 and the common terminal member ( 18) must be placed between.

In view of the foregoing, it is now apparent that the present invention has the various advantages described above.

While the invention has been described fully with reference to the accompanying drawings and in connection with the various claims related thereto, it should be noted that various changes and modifications will be apparent to those skilled in the art.

However, changes and modifications should be construed as being included within the true scope of the present invention as long as they do not depart from the scope of the present invention.

Claims (1)

A piezoelectric device composed of one piezoelectric resonant plate having primary and secondary surfaces opposite to each other, having at least one electrode layer formed on each of the primary and secondary surfaces of the piezoelectric resonance plate, and having a conductive terminal member. Are of the same number as the electrode layers, and are electrically connected to respective electrode layers on the primary and secondary surfaces of the piezoelectric resonant plate, and at least one conductive elastic sheet is provided on one of the terminal member members and one of the terminal members. A piezoelectric device, characterized in that the sandwich is sandwiched between the electrode layers which are electrically connected.

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