Abstract:
A piezoelectric resonator supporting structure supports a piezoelectric resonator at a supporting member through a connecting member. The piezoelectric resonator is adapted to vibrate in a longitudinal vibration mode. A portion of the fixing member that contacts the piezoelectric resonator is made of a vibration transmission restricting material for restricting transmission of vibration from the piezoelectric resonator to the supporting member through the connecting member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a piezoelectric resonator supporting structure and a piezoelectric component including the same, and more particularly to a piezoelectric resonator supporting structure for supporting a piezoelectric resonator on a supporting member, such as a base, via a fixing member. 
     2. Description of the Related Art 
     FIG. 21 illustrates an example of a piezoelectric resonator relating to a background of the invention and to which the present invention is applied. FIG. 22 is a plan view showing a state in which insulating films are formed on a substrate of the piezoelectric resonator. The piezoelectric resonator  10  shown in FIG. 21 includes a rectangular parallelopiped substrate  12  which is 4 mm long, 1 mm wide, and 1 mm high. The substrate  12  includes twenty piezoelectric layers  14  that are stacked on each other and formed of, for example, piezoelectric ceramic material. These piezoelectric layers  14  have the same dimensions. As indicated by the arrows in FIG. 21, the piezoelectric layers  14  are polarized in a longitudinal direction of the substrate  12  such that the polarization directions of adjacent piezoelectric layers  14  are opposite to each other. The piezoelectric layers  14  at both ends of the substrate  12  are not polarized. 
     Internal electrodes  16  are disposed between piezoelectric layers  14  of the substrate  12 , extend perpendicular to the longitudinal direction of the substrate  12  and are separated from each other in the longitudinal direction of the substrate  12 . The internal electrodes  16  are arranged to cover the entire main surfaces of the piezoelectric layers  14 . Therefore, the internal electrodes  16  are exposed at four side surfaces of the substrate  12 . 
     A groove  17  is formed in a center portion, in a widthwise direction of the substrate  12 , of one of the side surfaces of the substrate  12 . At one of the portions, in the widthwise direction of the substrate  12 , of the one side surface of the substrate  12  where the groove  17  is not formed, ends of alternate internal electrodes  16  are disposed so as to be covered with insulating films  18 . Ends of other alternate internal electrodes  16  are disposed at the other of the portions, in the widthwise direction of the substrate  12 , of the one side surface of the substrate  12  where the groove  17  is not formed. 
     At the one portion of the one side surface of the substrate  12 , an external electrode  22  is disposed on, for example, the insulating films  18  provided on the alternate electrodes  16  so as to be connected to the alternate electrodes  16  provided on the other portion. At the other portion of the one side surface of the substrate  12 , an external electrode  24  is disposed on, for example, the insulating films  20  provided on the alternate electrodes  16  so as to be connected to the alternate electrodes  16  provided on the one portion. 
     In the piezoelectric resonator  10  shown in FIG. 21, the external electrodes  22  and  24  are used as input/output electrodes. Since electric fields are applied between the internal electrodes  16  of adjacent layers when a signal is applied to the external electrodes  22  and  24 , the piezoelectric layers  14 , excluding those at both ends of the substrate  12 , become piezoelectrically active. In this case, electrical fields opposite in direction are applied to the piezoelectric layers  14  of the substrate  12  that are polarized in opposite directions. Therefore, the piezoelectric layers  14  as a whole tend to expand and contract in the same direction. In other words, when alternating current electric fields in the longitudinal direction of the substrate  12  are applied to the individual piezoelectric layers  14  by the internal electrodes  16  and the internal electrodes  16  connected to the external electrodes  22  and  24 , so that a driving force that expands and contracts the individual piezoelectric layers  14  is generated thereat, the entire piezoelectric resonator  10  is excited with a fundamental vibration of a longitudinal vibration, with the center portions, in the longitudinal direction of the substrate  12 , of the substrate  12  acting as nodes. 
     A description will now be provided of a conventional piezoelectric component in which the piezoelectric resonator  10  shown in FIG. 21 is mounted via fixing members on a base which defines a supporting member. 
     FIG. 23 illustrates a state before the piezoelectric resonator of the conventional piezoelectric component is fixed. FIG. 24 illustrates a state after the piezoelectric resonator of the piezoelectric component has been fixed. The piezoelectric component  1  shown in FIGS. 23 and 24 includes a base  2  defining a supporting member. Two pattern electrodes  3  are provided on the base  2 . Fixing members  4  made of a urethane-type electrically conductive material, that is, a urethane-type synthetic resin containing 85 wt % of Ag are provided on respective center portions, in the longitudinal direction of the external electrodes  22  and  24 , of the external electrodes  22  and  24 . The fixing members  4  are bonded to the two pattern electrodes  3  on the base  2  via an electrically conductive paste  5  made of an epoxy-type electrically conductive material, that is, an epoxy-type synthetic resin containing Ag. This causes the external electrodes  22  and  24  of the piezoelectric resonator  10  to be electrically coupled to the respective pattern electrodes  3  on the base  2 , through the respective fixing members  4 , whereby the piezoelectric resonator  10  is fixed to the base  2  through the fixing members  4 . 
     In this case, the larger dimension W 1  of the upper portion of each fixing member  4  of the piezoelectric resonator  10  is in the longitudinal direction thereof, the easier it is for vibration to be transmitted. The dimension W 1  is in the range of from 1.0 mm to 1.4 mm. 
     The relationship between the transmission of vibration and dimension W 2  of the lower portion of each fixing member  4  of the piezoelectric resonator  10  in the longitudinal direction thereof is small, but with regard to the strength with which the base  2  and the fixing members  4  are grounded, it is, for example, set equal to or greater than 0.5 mm. 
     Although the amount of vibration transmitted varies with the hardness of the fixing members  4  and the amount of Ag contained in the fixing members  4 , it can be reduced by a certain amount even in a direction of thickness of the fixing members  4  by thickness t 1  of the fixing members  4 . The larger the value of thickness t 1 , the smaller the amount of vibration transmitted. The thickness t 1  has an upper limit due to the height of the piezoelectric components produced. It is within a range of, for example, from 130 μm to 170 μm. 
     Although thickness t 2  (shown in FIG. 23) prior to bonding with the electrically conductive paste  5  is not directly related to the transmission of vibration, when the electrically conductive paste  5  is thick, the fillet size with respect to the fixing members  4  becomes large, thereby increasing the amount of vibration transmitted. On the other hand, when it is thin, the strength with which the fixing members  4  is grounded is reduced. Therefore, the thickness t 2  is in a range of from 35 μm to 55 μm. 
     The piezoelectric component  1  shown in FIGS. 23 and 24 possess the impedance characteristics and the phase characteristics illustrated in FIG.  25  and the filter characteristics illustrated in FIG.  26 . 
     However, in the above-described conventional piezoelectric component  1 , when the dimension W 1  of the upper portion of each fixing member  4  is made smaller in order to restrict the transmission of vibration, the dimension W 2  of the lower portion of the fixing members  4  inevitably becomes small, so that sufficient supporting strength cannot be obtained. On the other hand, in order to make the dimension W 2  of the lower portion of the fixing members  4  equal to or greater than a specification value that is equal to or greater than 0.5 mm, the dimension W 1  of the upper portion of the fixing members  4  becomes equal to or greater than 0.9 mm, making it easier for vibration to be transmitted. 
     In addition, in the above-described conventional piezoelectric component  1 , when the thickness t 1  of the fixing members  4  is made large in order to restrict the transmission of vibration, the manufactured piezoelectric component  1  becomes taller, so that the goal of making light, thin, short, small piezoelectric components cannot be achieved. Further, there has been an increasing demand for decreasing the maximum height of current products from 1.9 mm to 1.7 mm or 1.5 mm, so that the fixing members  4  are becoming shorter and shorter, making it necessary to investigate ways to reduce the amount of energy transmitted. 
     Still further, in the above-described conventional piezoelectric component  1  having the above-described structure and dimensions, in order to restrict the transmission of vibration, it is necessary to improve the materials used for the fixing members  4  and the electrically conductive paste  5 . An effective lower Young&#39;s modulus cannot be obtained due to strength requirements and poor cutting performance during cutting of a piezoelectric resonator or cutting operations carried out using a dicing machine. Still further, since it is clear that vibration is transmitted through Ag fillers in the fixing members  4 , the amount of vibration transmitted can be restricted by reducing the amount of Ag. However, since, in order to ensure electrical conduction, current electrically conductive pastes are based on urethane-type synthetic resin, the amount of Ag contained cannot be reduced to an amount that is 80 wt % or less. 
     SUMMARY OF THE INVENTION 
     To overcome the above described problems, preferred embodiments of the present invention provide a piezoelectric resonator supporting structure which can restrict the amount of vibration transmitted from a piezoelectric resonator to a supporting member while maintaining the strength with which the piezoelectric resonator is held by the supporting member; and a piezoelectric component including the same. 
     One preferred embodiment of the present invention provides a piezoelectric resonator supporting structure for supporting a piezoelectric resonator on a supporting member via a fixing member, the piezoelectric resonator being adapted to be vibrate in a longitudinal vibration mode, wherein at least a portion of the fixing member that contacts the piezoelectric resonator is made of a vibration transmission restricting material for restricting transmission of vibration from the piezoelectric resonator to the supporting member through the fixing member. 
     In such a piezoelectric resonator supporting structure of this preferred embodiment of the present invention, the portion of the fixing member that contacts the piezoelectric resonator may correspond to, for example, an outside portion or an inside portion of the fixing member. 
     In such a piezoelectric resonator supporting structure, a portion of the fixing member which extends from the portion of the fixing member that contacts the piezoelectric resonator to a portion of a portion of the fixing member at the supporting member side may be formed of the vibration transmission restricting material. 
     In such a piezoelectric resonator supporting structure, the vibration transmission restricting material may include urethane or silicone. 
     Another preferred embodiment of the present invention provides a piezoelectric component including any one of the above-described piezoelectric resonator supporting structures, wherein the supporting member is a base and a cover is provided on the base so as to cover the piezoelectric resonator. 
     In such a piezoelectric component, a plurality of the piezoelectric resonators may be provided. 
     In such piezoelectric resonator supporting structures and piezoelectric components including the same, a portion of the fixing member that contacts the piezoelectric resonator is formed of a vibration transmission restricting material, making it possible to restrict the transmission of vibration from the piezoelectric resonator to the supporting member while maintaining the strength with which the piezoelectric resonator is held by the supporting member. 
     Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is an exploded perspective view of a piezoelectric component in accordance with a preferred embodiment of the present invention. 
     FIG. 2 is a front view of the main portion of the piezoelectric component of FIG.  1 . 
     FIG. 3 shows a state before the piezoelectric resonator of the piezoelectric component of FIG. 1 is fixed. 
     FIG. 4 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 1 has been fixed. 
     FIG. 5 shows a graph illustrating the impedance characteristics and the phase characteristics of the piezoelectric component of FIG.  1 . 
     FIG. 6 shows a graph illustrating the filter characteristics of the piezoelectric component of FIG.  1 . 
     FIG. 7 shows a modification of the piezoelectric component of FIG.  1 . 
     FIG. 8 shows a state before a piezoelectric resonator of another preferred embodiment of the piezoelectric component in accordance with the present invention is fixed. 
     FIG. 9 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 8 has been fixed. 
     FIG. 10 shows a graph illustrating the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 8 and 9. 
     FIG. 11 shows a modification of the piezoelectric component shown in FIGS. 8 and 9. 
     FIG. 12 shows still another preferred embodiment of the piezoelectric component in accordance with the present invention. 
     FIG. 13 shows a state before the piezoelectric resonator of a modification of the piezoelectric component of FIG. 12 is fixed. 
     FIG. 14 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 13 has been fixed. 
     FIG. 15 shows an example of the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 13 and 14. 
     FIG. 16 shows another example of the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 13 and 14. 
     FIG. 17 shows a state before a piezoelectric resonator of another modification of the piezoelectric component of FIG. 12 is fixed. 
     FIG. 18 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 17 has been fixed. 
     FIG. 19 shows an example of the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 17 and 18. 
     FIG. 20 shows another example of the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 17 and 18. 
     FIG. 21 shows an example of a piezoelectric resonator to which the present invention is applied and serving as background of the present invention. 
     FIG. 22 is a plan view showing a state in which insulating films are provided on a base used in the piezoelectric resonator shown in FIG.  21 . 
     FIG. 23 shows a state before the piezoelectric resonator of a conventional piezoelectric component is fixed. 
     FIG. 24 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 23 has been fixed. 
     FIG. 25 shows a graph illustrating the impedance characteristics and the phase characteristics of the piezoelectric component shown in FIGS. 23 and 24. 
     FIG. 26 shows a graph illustrating the filter characteristics of the piezoelectric component shown in FIGS.  23  and  24 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 is an exploded perspective view of a piezoelectric component in accordance with a preferred embodiment of the present invention. FIG. 2 is a front view of the main portion of the piezoelectric component. FIG. 3 illustrates a state before the piezoelectric resonator of the piezoelectric component is fixed. FIG. 4 illustrates a state after the piezoelectric resonator of the piezoelectric component has been fixed. 
     The piezoelectric component  30  shown in FIG. 1 includes a base  32  defining a supporting member. Two recesses  34  each are preferably formed on opposite edges of the base  32 . Two pattern electrodes  36  and  38  are provided on one surface of the base  32 . The pattern electrode  36  is disposed between the one set of two opposing recesses  34 , with a substantially L-shaped portion extending from one end side of the pattern electrode  36  to the approximate center portion of the base  32 . The pattern electrode  38  is disposed between the other set of two opposing recesses  34 , with a substantially L-shaped portion extending from an opposite one end side of the pattern electrode  38  to the approximate center portion of the base  32 . The pattern electrodes  36  and  38  are arranged so as to wind around from the recesses  34  in the base  32  and towards the other surface. 
     The piezoelectric resonator  10  shown in FIG. 21 is fixed at the approximate center portion of the base  32  through fixing members  40 . Here, the two fixing members  40  are preferably located on approximate center portions, in the longitudinal direction of the two external electrodes  22  and  24 , of the two external electrodes  22  and  24  of the piezoelectric resonator  10 . 
     Outside portions  40   a  of one of the fixing members  40  that are portions which contact the external electrode  22  and that extend in a longitudinal direction of the piezoelectric resonator  10  are made of a vibration transmission restricting material, such as urethane or silicone, in order to restrict the transmission of vibrations from the piezoelectric resonator  10  to the base  32  via this fixing member  40 . Other portions  40   b  on both the outside portions  40   a  of this fixing member  40  are preferably made of a urethane-type electrically conductive material, that is, a urethane-type synthetic resin containing about 85 wt % of Ag. Possible urethane-type electrically conductive materials that can be used are not limited to urethane-type synthetic resin containing about 85 wt % of Ag, so that urethane-type synthetic resin containing, for example, from about 80 wt % to not more than about 85 wt % of Ag may also be used. 
     Similarly, both outside portions  40   a  of the other fixing member  40  that are portions that contact the external electrode  24  and are arranged to extend in the longitudinal direction of the piezoelectric resonator  10  are preferably made of a vibration transmission restricting material, such as urethane or silicone, in order to restrict the transmission of vibration from the piezoelectric resonator  10  to the base  32  through this fixing member  40 . Other portions  40   b  on both the outside portions  40   a  are formed of a urethane-type electrically conductive material, that is, a urethane-type synthetic resin preferably including about 85 wt % of Ag. 
     Here, although the dimension X 1  between the outside portions  40   a  of each of the fixing members  40  in the longitudinal direction of the piezoelectric resonator  10  is, for example, between about 0.3 mm to about 0.5 mm (which is about 7.5% to about 12.5% of the length of the piezoelectric resonator  10 ), it is, for example, equal to or less than about 1.0 mm (which is equal to or less than about 25% of the length of the piezoelectric resonator  10 ). The dimension X 1  may also have other values. The lower limit of the dimension X 1  is determined from the electrical conductivity between the external electrodes  22  and  24  and the pattern electrodes  36  and  38 . 
     The dimension X 2  of the lower portion of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is, for example, equal to or greater than about 0.5 mm, but may have other values. 
     The dimension X 3  of the upper portion of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is preferably, for example, equal to or less than about 1.5 mm, depending on the type of mounting jig used. Considering the dimension X 2 , it is preferably equal to or greater than about 0.8 mm (which is equal to or greater than about 20% of the length of the piezoelectric resonator  10 ). The dimension X 3  may have other values. 
     The thickness T 1  of the outside portions  40   a  of each fixing member  40  is, for example, about 20 μm, but may have other values. 
     The difference T 2  between the thickness of the other portions  40   b  on the outside portions  40   a  of each fixing member  40  and the thickness of the outside portions  40   a  of each fixing member  40  is equal to or greater than about 0 mm. 
     The thickness T 3  of each fixing member  40  is, for example, about 200 μm, but may have other values. 
     The two fixing members  40  are preferably bonded to the two pattern electrodes  36  and  38  on the base  32  with respective electrically conductive pastes  42  preferably made of an epoxy-type electrically conductive material, that is, an epoxy-type synthetic resin containing Ag. This causes the external electrodes  22  and  24  of the piezoelectric resonator  10  to be electrically coupled to the two pattern electrodes  36  and  38  on the base  32  through the fixing members  40 , whereby the piezoelectric resonator  10  is mounted on the base  32  through the fixing members  40 . 
     A metallic cap  44  defining a cover is placed over the piezoelectric resonator  10  so as to be disposed on the base  32 . In this case, an insulating material, such as insulating resin, is coated on the base  32  and the pattern electrodes  36  and  38  so that electrical conduction does not occur between the metallic cap  44  and the pattern electrodes  36  and  38 . By covering the piezoelectric resonator  10  with the metallic cap  44 , the electrical component  30 , including, for example, a piezoelectric resonator or a piezoelectric discriminator, is produced. In the piezoelectric component  30 , the pattern electrodes  36  and  38 , arranged so as to extend from the recesses  34  on the base  32  and around it towards the back surface, define input/output terminals for connection to an external circuit. 
     In the piezoelectric component  30  of FIG. 1, the outside portions  40   a  of each fixing member  40  being portions of the portions thereof that contact the piezoelectric resonator  10  are preferably made of a vibration transmission restricting material, making it possible to restrict the transmission of vibration from the piezoelectric resonator  10  to the base  32  while maintaining the strength with which the piezoelectric resonator  10  is held by the base  32 . 
     The piezoelectric component  30  shown in FIG. 1 possesses the impedance characteristics and the phase characteristics illustrated in FIG. 5, and the filter characteristics illustrated in FIG.  6 . From the impedance characteristics and the phase characteristics shown in FIG. 5, it can be seen that the amount of noise produced by the piezoelectric component  30  shown in FIG. 1 is much smaller than that produced by the piezoelectric component  1  shown in FIGS. 23 and 24. 
     When the temperature changes from 25° C. to −30° C., the center frequency in the piezoelectric component  30  of FIG. 1 increases by about 0.5 kHz, whereas the center frequency in the piezoelectric component  1  in FIGS. 23 and 24 increases by about 1.5 kHz. Accordingly, compared to the piezoelectric component  1  of FIGS. 23 and 24, the piezoelectric component  30  of FIG. 1 provides excellent temperature characteristics. 
     FIG. 7 illustrates a modification of the piezoelectric component shown in FIG.  1 . The piezoelectric component  30  shown in FIG. 7 differs from the piezoelectric component  30  shown in FIG. 1 in that other portions  40   b  on outside portions  40   a  of each fixing member  40  are formed thin portions that have a thickness which is about the same as that of the outside portions  40   a  of each fixing member  40 . Therefore, compared to the piezoelectric component  30  shown in FIG. 1, the piezoelectric component  30  shown in FIG. 7 can be made thinner. 
     FIG. 8 illustrates a state before the piezoelectric resonator of another preferred embodiment of the piezoelectric component in accordance with the present invention is fixed. FIG. 9 illustrates a state after the piezoelectric resonator of the piezoelectric component has been fixed. 
     The piezoelectric component  30  shown in FIGS. 8 and 9 differs from the piezoelectric component  30  of FIG. 1 in that inside portions  40   c  of fixing members  40  that are portions which contact external electrodes  22  and  24  and that are located at approximate center portions, in a longitudinal direction of the piezoelectric resonator  10 , of the piezoelectric resonator  10  are preferably made of a vibration transmission restricting material, such as urethane or silicone, to restrict the transmission of vibration from the piezoelectric resonator  10  to the base  32  through the fixing members  40 . It also differs in that other portions  40   d  on the inside portions  40   c  are preferably made of a urethane-type electrically conductive material, that is, urethane-type synthetic resin including about 85 wt % of Ag. 
     The dimension x 1  of the inside portion  40   c  of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is not more than about 80% of dimension x 3  of the upper portion of each fixing member  40 . However, the dimension X 1  may have other values. 
     The dimension x 2  of the lower portion of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is, for example, equal to or greater than about 0.5 mm, but may have other values. 
     The dimension x 3  of the upper portion of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is preferably equal to or less than about 1.5 mm, depending on the type of mounting jig used. However, the dimension X 3  may have other values. 
     The thickness T 1  of the inside portion  40   c  of each fixing member  40  is, for example, about 20 μm, but may have other values. 
     The difference T 2  between the thickness of the other portions  40   d  on the inside portions  40   c  and the thickness of the respective inside portions  40   c  of the fixing members  40  is equal to or greater than about 0 mm. 
     The thickness T 3  of each fixing member  40  is, for example, about 200 μm, but may have other values. 
     The piezoelectric component  30  shown in FIGS. 8 and 9 achieves advantages similar to those of the piezoelectric component  30  shown in FIG.  1 . 
     The piezoelectric component  30  shown in FIGS. 8 and 9 possess the impedance characteristics and the phase characteristics illustrated in FIG.  10 . From, for example, the impedance characteristics and the phase characteristics shown in FIG. 10, it can be seen than the amount of noise produced by the piezoelectric component  30  of FIGS. 8 and 9 is much smaller than that produced by the piezoelectric component  1  shown in FIGS. 23 and 24. It can be seen that the noise produced by the piezoelectric component  30  of FIG. 1 is much smaller than that produced by the piezoelectric component  30  of FIGS. 8 and 9. 
     The center portions of the piezoelectric resonator  10  in the longitudinal direction thereof define nodal points and displacement increases as the distance from the center portions increases, so that the portions of the fixing members  40  of the piezoelectric component  30  of FIG. 1 made of a vibration transmission restricting material are located towards the outer sides of the piezoelectric resonator  10  in the longitudinal direction thereof compared to those of the fixing members  40  of the piezoelectric component  30  shown in FIGS. 8 and 9. This is very effective in restricting the transmission of vibration from the piezoelectric resonator  10  to the base  32  through the fixing members  40 . 
     FIG. 11 illustrates a modification of the piezoelectric component of FIGS. 8 and 9. The piezoelectric component  30  of FIG. 11 differs from the piezoelectric component  30  shown in FIGS. 8 and 9 in that other portion  40   d  on an inside portion  40   c  of each fixing member  40  has a thickness which is the same as that of its corresponding inside portion  40   c.  The piezoelectric component  30  of FIG. 11 can be made thinner than the piezoelectric component  30  of FIGS. 8 and 9. 
     FIG. 12 shows still another preferred embodiment of the piezoelectric component in accordance with the present invention. The piezoelectric component  30  of FIG. 12 differs from the piezoelectric component  30  of FIG. 1 in that both outside portions  40   e  of each fixing member  40  that are portions which contact external electrodes  22  and  24  and pattern electrodes  36  and  38  and that are arranged to extend in a longitudinal direction of a piezoelectric resonator  10  are preferably made of a vibration transmission restricting material, such as urethane or silicone, to restrict the transmission of vibration from the piezoelectric resonator  10  to the base  32  through each fixing member  40 . The remaining inside portion  40   f  of each fixing member  40  is preferably made of an epoxy-type electrically conductive material, that is, epoxy-type synthetic resin containing Ag or other suitable material. 
     The dimension X 1  between the outside portions  40   e  of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is, for example, about 0.3 mm to about 0.5 mm (which is about 7.5% to about 12.5% of the length of the piezoelectric resonator  10 ), or equal to or less than about 1.0 mm (which is equal to or less than about 25% of the length of the piezoelectric resonator  10 ). The dimension X 1  may have other values. The lower limit of the dimension X 1  is determined by the electrical conductivity between the external electrodes  22  and  24  and the pattern electrodes  36  and  38 . 
     The dimension X 2  of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is greater than the dimension X 1 . From the point of view of strength, the dimension X 2  is, for example, equal to or greater than about 0.8 mm (which is equal to or greater than about 20% of the length of the piezoelectric resonator  10 ). The dimension X 2  may have other values. 
     The thickness T 1  of each fixing member  40  is about 20 μm to about 100 μm, but may have other values. 
     The two fixing members  40  are bonded at their inside portions  40   f,  preferably made of an epoxy-type electrically conductive material, to the two pattern electrodes  36  and  38  on the base  32 . 
     The piezoelectric component  30  of FIG. 12 achieves advantages similar to those of the piezoelectric component  30  of FIG. 1, and can be made thin. 
     In producing the piezoelectric component  30  of FIG. 12, the step of printing an electrically conductive paste after the formation of the fixing members  40  is not required, so that the problem of variations in the characteristics thereof caused by electrically conductive paste moving onto the fixing members  40  and the problem of reduced effectiveness in restricting the transmission of vibration almost never occur. 
     FIG. 13 illustrates a state before the piezoelectric resonator used in a modification of the piezoelectric component of FIG. 12 is fixed. FIG. 14 shows a state after the piezoelectric resonator used in the modified piezoelectric component of FIG. 13 has been fixed. The piezoelectric component  30  shown in FIGS. 13 and 14 differs from the piezoelectric component  30  of FIG. 12 in that an inside portion  40   f  of each fixing member  40  is preferably made of a urethane-type electrically conductive material containing Ag, that is, urethane-type synthetic resin containing Ag and has a thickness that is greater than the thickness of outside portions  40   e  made of a vibration transmission restricting material so as to cover the outside portions  40   e.  Using an electrically conductive paste  42  including an epoxy-type electrically conductive material, the fixing members  40  are bonded to two electrode patterns  36  and  38  so that the inside portions  40   f  of the fixing members  40  are bonded therewith. 
     In this case, thickness T between the electrically conductive paste  42  and the external electrode  22  and the external electrode  24  of the piezoelectric resonator  10  is, for example, in the range of about 50 μm, which is about the same as the thickness of the outside portions  40   e  of the fixing members  40 . 
     The thickness of the electrically conductive paste  42  is preferably, for example, about 80 μm. 
     The piezoelectric component  30  shown in FIGS. 13 and 14 achieves advantages similar to those achieved by the piezoelectric component  30  of FIG.  12 . 
     FIG. 15 shows the impedance characteristics and the phase characteristics that the piezoelectric component  30  shown in FIGS. 13 and 14 possess, when the dimension L between the outside portions  40   e  and  40   e  of each fixing member  40  is about 0.314 mm. FIG. 16 shows the impedance characteristics and the phase characteristics that the piezoelectric component  30  shown in FIGS. 13 and 14 possess, when the dimension L is about 0.316 mm. 
     FIG. 17 illustrates a state before a piezoelectric resonator of another modification of the piezoelectric component of FIG. 12 is fixed. FIG. 18 shows a state after the piezoelectric resonator of the piezoelectric component of FIG. 17 has been fixed. In the piezoelectric component  30  shown in FIGS. 17 and 18, an inside portion  40   g  of each fixing member  40  is preferably made of a vibration transmission restricting material, such as urethane or silicone, and an outside portion  40   h  of each fixing member  40  is preferably made of a urethane-type electrically conductive material, that is, a urethane-type synthetic resin including about 85 wt % of Ag so as to cover the inside portion  40   g  of each fixing member  40 . The fixing members  40  are bonded to two electrode patterns  36  and  38  preferably via an electrically conductive paste  42  made of an epoxy-type electrically conductive material or an epoxy-type synthetic resin containing Ag and arranged so as to cover the outside portion  40   h  of each fixing member  40 . 
     In this case, thickness T between the electrically conductive paste  42  and external electrodes  22  and  24  of the piezoelectric resonator  10  is, for example, in the range of about 50 μm, which is about the thickness of the inside portions  40   g  of the fixing members  40 . 
     The thickness of the electrically conductive paste  42  is, for example, about 80 μm. 
     The piezoelectric component  30  shown in FIGS. 17 and 18 achieves advantages similar to those achieved by the piezoelectric component  30  of FIG.  12 . 
     FIG. 19 shows the impedance characteristics and the phase characteristics achieved by the piezoelectric component  30  shown in FIGS. 17 and 18, when the dimension (L 1 +L 2 ) of the outside portion  40   h  at the upper portion of each fixing member  40  in the longitudinal direction of the piezoelectric resonator  10  is about 0.309 mm. FIG. 20 shows the impedance characteristics and the phase characteristics achieved by the piezoelectric component  30 , when the dimension (L 1 +L 2 ) is about 0.322 mm. 
     From the impedance characteristics and the phase characteristics illustrated in FIGS. 15,  16 ,  19  and  20 , it can be seen that the piezoelectric component  30  shown in FIGS. 13 and 14 generates a smaller amount of noise than the piezoelectric component  30  shown in FIGS. 17 and 18. 
     Although in the above-described piezoelectric components  30 , a piezoelectric resonator  10  having a special structure, shown in FIG. 21, is used, a differently structured piezoelectric resonator such as a single, plate-shaped piezoelectric resonator may also be used. 
     Although each of the portions of each of the above-described piezoelectric components  30  preferably has special dimensions and forms, it may be formed with other dimensions and forms. 
     Although in each of the above-described piezoelectric components  30 , special materials are used for the materials of the fixing members  40  and the electrically conductive pastes  42 , other materials may be used. 
     While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the forgoing and other changes in form and details may be made therein without departing from the spirit of the invention.