JPH0355910A - Electronic component - Google Patents

Abstract

PURPOSE:To simplify the manufacture and to improve the productivity by placing 1st and 2nd capacitors side by side on a board and connecting electrodes of the 1st and 2nd capacitors formed on the upper face of the substrate to electrodes of the 1st and 2nd capacitors formed on the lower face of the substrate respectively by an electric conductor line. CONSTITUTION:Electrodes 8a, 8b' of 1st and 2nd capacitors C1, C2 and electrodes 8a', 8b of 2nd and 1st capacitor C2 are formed to upper and lower faces of a ferrodielectric substrate 2 with inverting the top and bottom relation, then when a voltage is applied between the electrodes of the 1st capacitor and the electrodes of the 2nd capacitor, the 1st capacitor C1 and the 2nd capacitor C2 are excited in an opposite mode without fail. Thus, the excitation of the 1st and 2nd capacitors C1, C2 are cancelled and no excitation appears as a whole of the capacitor C. Moreover, when the ferrodielectric substrate 2 is subjected to shock or the like, a piezoelectric noise voltage nearly equal to each other is generated in the 1st and 2nd capacitors C1, C2. In this case, the piezoelectric noise voltage caused in the 1st capacitor C1 is opposite in phase to the piezoelectric noise voltage caused in the 2nd capacitor C2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electronic components such as piezoelectric filters and capacitors using ferroelectric substrates. As an example of this type of electronic component, an energy trapping type two-stage coupling filter 40 shown in FIG. 6 is known. The ferroelectric substrate 41 has two multimode filter sections F11. It has F12 and one capacitor section CIO. This substrate 41 is a ferroelectric substrate such as a piezoelectric ceramic substrate, and is polarized P in the thickness direction from the bottom surface to the top surface. The filter 40 is of a three-terminal type, with input/output terminals 42 and 43 formed at the left and right ends of the upper surface of the substrate 41, and a common terminal 44 formed at the center of the lower side of the lower surface of the substrate 41.

The filter section Fil is composed of two input/output vibrating electrodes 45a and 45b formed on the upper left surface of the substrate 4l and one common vibrating electrode 46 formed on the lower surface of the substrate 41 opposite to these. Similarly, filter section F1
2 Two input/output vibration electrodes 4 on the upper right side of the IT board 41
8a. 48b and one common vibrating electrode 49 placed opposite these.

The capacitor unit CIO is located between the filter units Fil and F12, and includes capacitors i 47a. 47b.

These filter sections F11. F12 and capacitor part CI
O is electrically connected by a conductor line. At this time, the input/output signal line side is always formed on the upper surface of the substrate 41, and the common signal line side is always formed on the lower surface of the substrate 41.

FIG. 7 shows an electric circuit of the filter 40 having the above configuration. Filter parts Fil and F12 having the same polarization P direction are inserted in parallel between the input/output signal line and the common signal line with the capacitor part CIO interposed therebetween.

By the way, when the region of the substrate 41 where the capacitor portion CIO is formed is polarized P, the capacitor electrodes 47a . When a signal voltage is applied to 47b, the substrate 4 sandwiched between electrodes 47a and 47b
One part is mechanically excited by electrostriction. Therefore, the capacitor section CIO acts as a resonator, degrading the electrical characteristics of the filter 40. Furthermore, the filter 40
When the capacitor CIO receives a shock or vibration from the outside world, a voltage is generated in the capacitor section CIO due to the Viezo effect. This is,
This piezoelectric noise, so-called piezoelectric noise, also deteriorates the electrical characteristics of the filter 40. Therefore, as a countermeasure against this problem, (1) A method in which the polarization treatment is not performed only in the area where the capacitor portion CIO is formed on the substrate 41. (2) A method in which the polarization process is not performed only in the region where the capacitor portion CIO is formed. The damping process is applied by mounding solder on the surface of the 47b or applying a resin material. However, these methods require complicated work, resulting in decreased productivity and a resulting deterioration in yield. Therefore, an object of the present invention is to provide an electronic component having a capacitor portion formed on a ferroelectric substrate, which can obtain excellent electrical characteristics without requiring complicated manufacturing processes such as polarization treatment and damping treatment. The goal is to provide the following. In order to solve the problem beyond the means for determining the problem, the electronic component according to the present invention is
A capacitor section formed on a ferroelectric substrate having a polarization direction in the thickness direction is composed of a first capacitor section and a second capacitor section, and the first capacitor section and the second capacitor section are arranged on the substrate. The electrodes of the first capacitance section and the electrodes of the second capacitance section which are juxtaposed and formed on the top surface of the substrate are connected to the electrodes of the second capacitance section and the electrodes of the first capacitance section formed on the bottom surface of the substrate, respectively. It is characterized by being connected by a railway line.

Effect In the above configuration, when a voltage is applied between the electrodes of the first capacitor section and between the electrodes of the second capacitor section, the ferroelectric substrate sandwiched between the electrodes is mechanically excited by electrostriction. At this time, the electrodes of the first capacitor part and the electrodes of the second capacitor part formed on the upper surface of the dielectric substrate are respectively connected to the electrodes of the second capacitor part formed on the lower surface of the dielectric substrate.
Since the electrode of the capacitor part and the electrode of the first capacitor part are connected to each other by a conductor line, it is excited in a reverse phase mode in which, for example, when the electrode on the first capacitor side extends, the electrode on the second capacitor side contracts. Therefore, even if the first capacitor section and the second capacitor section are excited, they cancel each other out, and no excitation appears in the capacitor section as a whole.

Further, when the ferroelectric substrate is subjected to impact or vibration, substantially equal piezoelectric noise voltages are generated in the first capacitor section and the second capacitor section. At this time, since the first capacitor part and the second capacitor part are formed on the upper and lower surfaces of the ferroelectric substrate with the vertical relationship reversed, the piezoelectric noise voltage generated in the first capacitor part is generated in the second capacitor part. The voltage is in the opposite phase to the piezoelectric noise voltage.
Therefore, the piezoelectric noise voltage generated in the first capacitance section and the piezoelectric noise voltage generated in the second capacitance section cancel each other out via the conductor line connecting the first capacitance section and the second capacitance section.

Furthermore, since the first capacitor section and the second capacitor section formed on the ferroelectric substrate are connected in parallel, the sum of the capacitances of the first capacitor section and the second capacitor section is formed on the substrate. This is the capacitance of the capacitor. DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of electronic components according to the present invention will be described below with reference to the accompanying drawings.

Figure 1 shows an energy trapping two-stage coupling filter 1. The ferroelectric substrate 2 has two filter sections F1. It has F2 and a capacitor section C. This substrate 2 is polarized P in the thickness direction from the bottom surface to the top surface. As the substrate 2, a ferroelectric substrate such as a piezoelectric ceramic substrate of Pb(ZrTi)Os or BaTiOs is used. The filter 1 is of a three-terminal type, and has input/output terminals 3a. 3b are formed on the upper and lower surfaces of the left and right ends of the board 2, and common terminals 7.7
' are formed on the upper and lower surfaces of the center portion of the lower side of the substrate 2.

The filter section F1 includes two input/output vibrating electrodes 4a. 4b and one common vibration electrode 5 formed on the lower surface of the substrate 2 in opposition to these. Similarly, the filter section F2 has two input/output vibration poles 9a. 9b and one common vibrating electrode 10 placed opposite to these. Capacitor section C is located between filter section F1 and filter section F2. The capacitor section C is composed of a first capacitor section C1 and a second capacitor section C2, which are arranged side by side on the substrate 2. It is preferable that the capacitances of the first capacitive part C1 and the second capacitive part C2 be designed to have approximately the same value. The first capacitive part C1 is formed at a position to the left of the center of the substrate 2, and has an input/output signal side electrode 8a formed on the upper surface of the substrate 2 and a common signal side formed on the lower surface of the substrate 2 opposite thereto. It consists of an electrode 8b. Similarly, the second capacitor C2 is formed at a position near the center right of the substrate 2, and is connected to the input/output signal side electrode 8a' formed on the lower surface of the substrate 2 and the substrate 2 opposite thereto.
It consists of a common signal side electrode 8b' formed on the upper surface of the. These filter sections Fl. F2 and capacitor section C are electrically connected by a conductor line. That is, on the input/output signal line side, the input/output terminal 3a has one output signal line 11.
a - input/output vibration t-pole 4a, 4b of filter section F1 - single output signal line 1lb - input/output signal side electrode 8a of first capacitive part C1 - single output signal line 11c - relay terminal 6.6゛ single output signal line lid - The input/output signal side electrode 81 of the second capacitor section C2 - the input/output vibrating electrode 9a of the filter section F2. It consists of 9b single output signal line 11f single output terminal 3b. On the other hand, on the common signal line side, the common vibrating electrode 5 of the filter section F1 - the common signal line 12a - the first
Common signal side electrode 8b of capacitive part C1-common signal line 12b
It consists of one common terminal 7, 7.degree., one common signal line 12c, one common signal side electrode 8b' of the second capacitance section C2, one common signal line 12d, and a common vibrating electrode 10 of the filter section F2. Here, the relay terminal 6.6' and the common terminal 7.7' are electrically connected by an external electrode or the like formed in a later process. The input/output signal line side is formed from the upper left surface to the lower right surface of the substrate 2, and conversely, the common signal line side is formed from the lower left surface to the upper right surface of the substrate 2. The input/output signal line changes from the upper surface to the lower surface of the substrate between the first capacitive section C1 and the second capacitive section C2. FIG. 2 shows a vertical sectional view taken along line xx' in FIG. 1.

In the above configuration, the electrodes 8a. 8b
and the electric power si8a' of the second capacity group C2. 8b' are formed on the upper and lower surfaces of the ferroelectric substrate 2 with the vertical relationship reversed, so when a voltage is applied between the electrodes of the first capacitor part and between the electrodes of the second capacitor part, the first capacitor The section C1 and the second capacitive section C2 are always excited in opposite phase mode. Therefore, even if the first capacitor section C1 and the second capacitor section C2 are excited, they cancel each other out, and no excitation appears in the capacitor section C as a whole. Furthermore, when the ferroelectric substrate 2 receives an impact or the like, piezoelectric noise voltages of approximately equal values are generated in the first capacitive portion C1 and the second capacitive portion C2. At this time, the piezoelectric noise voltage generated in the first capacitance section C1 becomes a voltage in the opposite phase to the piezoelectric noise voltage generated in the second capacitance section C2. Therefore, the piezoelectric noise voltages generated in the first capacitance section C1 and the second capacitance section C2 cancel each other out via the conductor line.

Figure 3 shows the electrical circuit of filter 1 shown in Figure 1. FIG. 4 shows an equivalent electric circuit to the electric circuit shown in FIG. 3. Capacitive part CI in which filter parts F1 and F2 have opposite polarization P directions
and C2 are inserted in parallel between the input/output signal line and the common signal line. The first capacitive part C1 and the second capacitive part C1
Since the capacitive part C2 is connected in parallel, the first capacitive part C
1 and the capacitance of the second capacitance section C2 becomes the capacitance of the capacitor section C formed on the substrate. Figure 5 shows the sealing plate 13 attached to the filter 1 from above and below.
a. Chip type piezoelectric filter component 14 with 13b glued
It shows.

External input/output electrodes (A) and (B) are input/output terminals 3, respectively.
a. 3b, the external common electrode (D) is connected to the common terminal 7.7', and the external relay electrode (C) is connected to the relay terminal 6.6'. It is formed of.

Note that the electronic component according to the present invention is not limited to the above-mentioned embodiments, and can be variously modified within the scope of the gist.

Electrodes ga. of capacitive parts CI and C2. 8b. 8at'
．． The position and shape of 8b' are not limited to those in the embodiment, and any arbitrary position and shape can be adopted. For example, in the embodiment, the first capacitor section C1 and the second capacitor section C
2 are a pair of opposing electrodes 8a. 8b and 8a',
8b' is shown, but the electrodes may be further subdivided into many pairs of opposing electrodes, and these may be combined.

Effects of the Invention As is clear from the above explanation, according to the present invention, the electrodes of the first capacitor part and the electrodes of the second capacitor part are formed on the upper and lower surfaces of the ferroelectric substrate with their vertical relationship reversed. Therefore, the excitation generated in the first capacitor and the second capacitor cancel each other out, and the complicated excitation prevention treatments that were previously required, such as polarizing the ferroelectric substrate except for the capacitor, or There is no need to apply damping to the electrodes, providing highly productive electronic components. Furthermore, when the ferroelectric substrate receives shock or vibration from the outside world, a piezoelectric noise voltage of approximately equal value is generated in the first capacitor section and the second capacitor section. At this time, the piezoelectric noise voltage generated in the first capacitor section has a reverse phase with respect to the piezoelectric noise voltage generated in the second capacitor section. Therefore, the piezoelectric noise voltage generated in the first capacitance section and the piezoelectric noise voltage generated in the second capacitance section cancel each other out, reducing the piezoelectric noise of the electronic component, resulting in an electronic component with improved electrical characteristics. Can be provided.

[Brief explanation of drawings]

1, 2, 3, 4, and 5 show examples of electronic components according to the present invention, FIG. 1 is a plan view of a ferroelectric substrate, and FIG. 2 is a top view of a ferroelectric substrate. 3 is an electric circuit diagram of FIG. 1, FIG. 4 is an equivalent electric circuit diagram of FIG. 3, and FIG. 5 is a perspective view showing the external appearance of electronic components. . 6th
7 show conventional electronic components, FIG. 6 is a plan view of a ferroelectric substrate, and FIG. 7 is an electric circuit diagram of FIG. 6.

Claims (1)

[Claims] 1. A capacitor section formed on a ferroelectric substrate having a polarization direction in the thickness direction is composed of a first capacitor section and a second capacitor section, and the first capacitor section and the second capacitor section are juxtaposed on the substrate. The electrodes of the first capacitance section and the electrodes of the second capacitance section formed on the top surface of the substrate are connected to the electrodes of the second capacitance section and the electrodes of the first capacitance section formed on the bottom surface of the substrate by conductor lines, respectively. An electronic component characterized by being connected.