JPH036026Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a composite piezoelectric resonator used in a mobile object identification system and the like.

(Prior Art) In general, in a mobile object identification system, for example, as shown in FIG. 3, the transponder 3 emits a response wave (code pulse) of the same or different frequency from the antenna 4. In the mobile object identification system, the transponder 3 includes a plurality of piezoelectric ceramic resonance units. X ₁ , X ₂ ,
. . , Xn are connected in parallel, and the resonance frequency of each piezoelectric resonance unit X ₁ , X ₂ , .

The above piezoelectric ceramic resonant unit X ₁ , X ₂ , ..., Xn
As shown in FIG. 2, electrodes 6 and 7 formed on opposite principal surfaces of a rectangular piezoelectric substrate 5 are opposed to each other at approximately the center of the piezoelectric substrate 5, and these electrodes 6, The piezoelectric substrate 5 located between the
A piezoelectric resonator that utilizes energy-trapped thickness-shear vibration is used. Conventionally, the piezoelectric ceramic resonant units X ₁ , X ₂ , ..., Xn are
As shown in FIG. 3, the electrodes 6 and 7 are adhered to the patterns 9 and 10 of the printed circuit board 8 with conductive paint, with the thickness-slide vibration parts floating, and the lead terminals 1 are attached to the patterns 9 and 10.
After soldering 1 and 12 and covering the printed circuit board 8 with insulating spacers 13 as shown in FIG.
A composite piezoelectric ceramic for a transponder is obtained by inserting the metal case 14 through an opening at one end, leading out the lead terminals 11 and 12 from the opening of the metal case 14, and sealing this opening with a spacer 15 and a sealing material 16. It is modularized as a resonator.

By the way, in the composite piezoelectric resonator for transponders such as the one described above, the piezoelectric resonator unit is
X ₁ , X ₂ , .
It is difficult to bond X ₁ , X ₂ , ..., Xn, and _{the piezoelectric ceramic resonant unit X 1 ,}
There was a fear that the printed circuit board 8 might fall off. In addition, the piezoelectric ceramic resonant units X ₁ , X ₂ , ...,
It is difficult to enlarge the gap between Xn and the printed circuit board 3, and if foreign matter enters this gap, the vibrations of the piezoelectric ceramic resonant units X ₁ , X ₂ , . . . , Xn will be inhibited. Furthermore, in order to prevent the sheet material 16 from entering the inside of the case 14, a spacer 15 was also required.

(Purpose of the invention) The purpose of the invention is to provide a low-cost composite piezoelectric resonator that has a small number of parts, is small, highly reliable, and reduces the number of production steps.

(Structure of the invention) Therefore, in the present invention, a plurality of energy trapping piezoelectric resonant units are spaced apart from each other between two opposing sides of a cutout hole provided in a single insulating substrate. They are inserted in the thickness direction of the insulating substrate, bridged, and supported by the insulating substrate at both ends, and the lead-out portions of the electrodes of these energy trapping type piezoelectric resonant units are inserted along the two sides of the notch in the insulating substrate. It is characterized in that it is electrically conductively connected to the respective running connection electrodes, and that lead terminals are electrically conductively bonded to each of the connection electrodes.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In Fig. 5, 21 is a piezoelectric ceramic resonant unit.
An insulating substrate supporting X ₁ , X ₂ , . . . , Xn, 22 an insulating spacer, 23 a case, and 24 lead terminals.

The insulating substrate 21 is a flat plate made of an insulating material such as alumina.
has a rectangular notch hole 25, as shown in FIG. 6a. Two opposing sides 25a and 25b of this notch hole 25 are each formed in a sawtooth shape. Connection electrodes 26 and 27 are formed outside the two sides 25a and 25b of the notch hole 25 along these two sides 25a and 25b. The connection electrodes 26 and 27 have a substantially constant width, and the notch holes 25
runs near the two sides 25a and 25b of the insulating substrate 21, as shown in FIG.
It has been extended to a. These connection electrodes 26, 27
is provided on at least one side of the insulating substrate 21.

As shown in FIG. 7, conductive paint 28 is applied to the sides 25a and 25b of the notch hole 25, and between the opposing valleys of these two serrated sides 25a and 25b, the insulating substrate 21 is coated with conductive paint 28. Piezoelectric ceramic resonant units X ₁ , X ₂ , .
Each electrode 5 of the piezoelectric ceramic resonant units X ₁ , X ₂ , ..., Xn is connected to a connecting electrode 26 by conductive paint 28
The piezoelectric ceramic resonant units X ₁ , X ₂ ,
..., each of the other electrodes 6 of Xn is connected to the connection electrode 27 by conductive paint 28, and
1.

As shown in FIG.
are soldered with solder 29, and insulating spacers 22, 22 are placed on the top and bottom of the insulating substrate 21. The insulating spacers 22, 22 have a notch hole (not shown) approximately equal to the notch hole 25 of the insulating substrate 21.
have. This allows the piezoelectric ceramic resonant unit to
Insulating spacer 2 on the vibrating part of X ₁ , X ₂ , ..., Xn
2 and 22 never touch. Then, the whole is inserted through an opening at one end of a metal case 23, the lead terminals 24 are led out from the opening of the case 23, and this opening is sealed with a sealing material 32. The case 23 has an inner dimension that is approximately equal to the cross-sectional dimension of the insulating substrate 21, and when the sealing material 32 is injected into the opening of the case 23, the sealing material 32
is prevented from entering the inside of the case 23. In other words, if the thickness of the insulating spacers 22, 22 is t, and the inner dimension of the case 23 is h, then
Set T+2t<h.

If you do the above, the piezoelectric ceramic resonant unit
X ₁ , X ₂ , .
5b, the piezoelectric ceramic resonant units X ₁ , X ₂ , . . . , _Xn can be easily attached to the insulating substrate ₂₁ . ..., there is no fear that Xn will fall off from the insulating substrate 21. Moreover, the piezoelectric ceramic resonant units X ₁ , X ₂ , ..., Xn are connected to the insulating substrate 21
The piezoelectric ceramic resonator unit
There is almost no fear that foreign matter will enter between X ₁ , X ₂ , ..., Xn.

In addition to transponders for mobile object identification systems, the present invention can be widely applied to composite piezoelectric ceramic resonators incorporating a plurality of energy-trapped piezoelectric resonant units in one case.

(Effects of the invention) As is clear from the detailed description above, according to the invention, multiple energy-trapped piezoelectric resonances can be achieved using a single insulating substrate with a relatively simple structure and having a notch inside. Since the unit is supported, a plurality of energy trapping type piezoelectric resonant units can be supported by a single part, which results in fewer manufacturing steps, lower costs, and higher reliability.

Furthermore, according to the present invention, a plurality of energy-trapped piezoelectric resonant units are housed within a single insulating substrate.
The plurality of energy-trapped piezoelectric resonant units are supported in a shelf-like manner at intervals, and the necessary wiring is performed between the plurality of energy-trapped piezoelectric resonant units and the lead terminals using connection electrodes formed on an insulating substrate, so that composite piezoelectric resonance is achieved. The child is significantly smaller.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a moving object identification system, Figure 2 is a perspective view of a thickness-shear piezoelectric ceramic resonator unit, Figure 3 is a plan view of the printed circuit board portion of a conventional composite piezoelectric ceramic resonator, and Figure 4 is FIG. 5 is a vertical cross-sectional view of a conventional composite piezoelectric ceramic resonator, and FIG. 6 is a vertical cross-sectional view of an embodiment of a composite piezoelectric ceramic resonator according to the present invention.
6b are a plan view and a front view of the insulating substrate, respectively, and FIG. 7 is an enlarged perspective view for explaining the attachment of the piezoelectric resonant unit to the insulating substrate. X ₁ , X ₂ ,..., Xn... Piezoelectric ceramic resonant unit, 21... Insulating substrate, 22... Insulating spacer,
23... Case, 24... Lead terminal, 25...
Notch holes (25a, 25b... sides), 26, 27
...Connection electrode, 28...Conductive paint.

Claims (1)

[Scope of utility model registration request] A plurality of energy trapping piezoelectric resonant units are each inserted in the thickness direction of the insulating substrate at intervals between two opposing sides of a cutout hole provided in a single insulating substrate, and are bridged at both ends. The lead-out portions of the electrodes of these energy trapping piezoelectric resonant units are electrically conductively connected to connection electrodes running along the two sides of the notch in the insulating substrate. , a composite piezoelectric resonator characterized in that lead terminals are electrically conductively bonded to each of the connection electrodes.