JPH06244565A - Electronic part - Google Patents

Abstract

PURPOSE:To prevent characteristics change and deterioration of an electronic part which are to be caused by a high voltage generated by pyroelectric charges or the like. CONSTITUTION:CTR powder, hardener, filler, etc., are added to thermosetting resin like epoxy based resin and kneaded. By using the above resin material for sealing, an electronic parts main body like a ceramics filter 11 is sealed so as to mutually connect outer terminals of the electronic parts contained in a case 12. The electronic parts sealed by this method has the function similar to a CTR element in addition to the original function, and pyroelectric charges due to a high temperature load and a high voltage load due to the pyroelectric charges are eliminated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to electronic components. Specifically, it relates to an electronic component in which an electronic component is packaged in a case.

[0002]

2. Description of the Related Art There are various kinds of electronic parts such as filters, oscillators, discriminators, traps, etc. When looking at the external appearance of these electronic parts, it is composed of an electronic part body and external terminals. Has been done. Many of these electronic components are packaged in various cases such as plastic and metal due to their use and design problems, and the lead-out portions of the external terminals are sealed with resin or the like. Conventionally, in these electronic components, since it is necessary to maintain insulation between external terminals, the external terminals are pulled out from the insulating part of the case and are sealed with an insulating resin or the like. It was

However, with an insulating resin such as an epoxy resin, which has been conventionally used for sealing electronic parts, electric charges are generated from the electronic parts main body due to temperature change and the like, and a high voltage is applied to the electronic parts main body, so that the electronic parts main body. It was not possible to prevent the problem of accelerating the deterioration of or changing the characteristics. In particular, when the electronic component body is made of piezoelectric ceramics, there is a problem that pyroelectric charge is generated due to a high temperature load during soldering and the characteristics are deteriorated due to depolarization of polarization.

For example, consider the case of a ceramic filter in which an electronic component body is made of a piezoelectric ceramic and an electronic component is packaged in a plastic case. FIG. 2 is a partially cutaway perspective view showing the structure of a typical ceramic filter 1. In this ceramic filter 1, a plurality of piezoelectric ceramic plates 2 having electrodes 3 on both sides are connected by an external terminal 4 and a terminal 5 for internal connection so as to have a predetermined circuit configuration (for example, a ladder type filter). The electronic component main body 6 is configured by housing the electronic component main body 6 in the case main body 7 having an opening on the lower surface, the lower opening of the case main body 7 is closed by the bottom lid 8, and the external terminal 4 is passed through the bottom lid 8 to externally And a portion of the bottom lid 8 where the external terminal 4 is pulled out is sealed with a resin (not shown). The piezoelectric ceramic plate 2 has
Generally, PbTiO ₃ —PbZrO ₃ ceramics and the like are widely used.

In such a ceramics filter 1, as in the case of soldering, the piezoelectric ceramics plate 2
When the temperature of the piezoelectric ceramic plate 2 is once set to a high temperature, the spontaneous polarization of the piezoelectric ceramic plate 2 becomes small due to the high temperature load.
The state shown in FIG. 3A is changed to the state shown in FIG. 3B, and pyroelectric charges 9 (charges generated on the crystal surface due to a temperature change in the magnitude of spontaneous polarization) are generated on the surface of the piezoelectric ceramic plate 2.
This pyroelectric charge 9 produces an electric field Edp that depolarizes the polarization P of the piezoelectric ceramics plate 2 as shown in FIG. 3B, so that the orientation degree in the piezoelectric ceramics plate 2 changes due to this electric field Edp. And ceramic filter 1
However, there is a drawback that the frequency characteristics of the are changed. In order to prevent this, it is necessary to use the piezoelectric ceramic plate 2 having a small insulation resistance, and there is a drawback that there is little room for selecting a piezoelectric material.

The present invention has been made in view of the above-mentioned drawbacks of conventional examples, and an object thereof is to prevent characteristic changes and deterioration of electronic parts due to high voltage load generated by pyroelectric charges or the like. Especially.

According to the electronic component of the present invention, in the electronic component in which the body of the electronic component is housed in a case such as a plastic case or a metal case, the through hole of the case into which the external terminal is inserted is sealed with a resin material having a thermistor function. It is characterized by having done.

[0008]

According to the electronic component of the present invention, the resistance value of the through hole of the case into which the external terminal is inserted suddenly decreases at a certain temperature (hereinafter, abbreviated as CTR).
Since it is sealed with the resin material having a function, the same effect as connecting the CTR element to the external terminal of the electronic component can be obtained.

That is, even when a high temperature load is applied to the electronic component body due to soldering or the like, when the temperature reaches the critical temperature of the sealing resin material, the resistance of the resin portion having the CTR function sharply decreases. Even if a pyroelectric charge is generated on the surface of the piezoelectric ceramic due to the pyroelectric charge, when the temperature is lowered again, it is discharged through the resin portion in the low resistance state, and the electric field due to the pyroelectric charge can be eliminated. It is possible to prevent a high voltage load from being applied to the electronic component body. Further, when the CTR is used, the resistance of the resin is drastically reduced as compared with the case where the NTC thermistor is used, so that the electric field due to the pyroelectric charge can be quickly canceled and the high voltage load is effectively prevented. You can

On the other hand, since the sealing resin maintains the insulating property (high resistance) when a high voltage or the like is not applied, it does not impair the original function of the case.

[0011]

1 shows the structure of a ceramic filter 11 according to an embodiment of the present invention. The case 12 is composed of a plastic case body 13 and a bottom lid 14 which are open on the lower surface, and an electronic component body 15 is housed in the case 12. The electronic component body 15 comprises a piezoelectric ceramics plate 16 having electrodes formed on both sides thereof, an external terminal 17 and a terminal 18 for internal connection, which are alternately stacked to form a desired circuit such as a ladder type filter. The external terminal 17 is drawn out from the through hole 19 of the bottom lid 14, and the through hole 19 of the bottom lid 14 from which the external terminal 17 is drawn out is electrically connected between the external terminals 17 by a sealing resin material 20 having a CTR function. Connected to each other.

Sealing resin material 20 having a CTR function
For example, thermosetting resin such as epoxy resin is used for CTR
The powder is kneaded and dispersed.

If the sealing resin material having such a CTR function is used to seal the external terminals 17 to each other, the CTR element is connected between the external terminals 17 of the electronic component body 15. Since various effects can be obtained, it is possible to prevent charges generated from the electronic component main body 15 and a high voltage load caused by the charges. For example, in FIG.
In the case of the ceramic filter 11 as shown in FIG. 3, the sealing resin material 20 having the CTR function is provided between the external terminals 17.
However, in a normal state, the sealing resin material 20 retains its insulating property, and serves the original purpose of the sealing resin. However, when the temperature of the electrode surface rises due to soldering and the surface temperature reaches the critical temperature of CTR, the sealing resin material 20 (that is,
If the spontaneous polarization is restored again due to the temperature drop, the pyroelectric charge generated on the surface due to the thermal shock due to soldering will cause the low resistance resistance of the sealing resin material 20 and the external terminal. It is possible to prevent the generation of the electric field Edp due to the pyroelectric charge by being discharged through 17, etc., and to prevent the depolarization of the spontaneous polarization due to the pyroelectric charge.

By using the resin material having the CTR function as the sealing resin material of the electronic component as described above, the original purpose of the sealing resin material is to seal the electronic component, and at the same time, the electronic component main body is sealed. It is possible to prevent changes in the characteristics of the electronic component body due to a load such as voltage. In addition, the external shape of the electronic component does not become large unlike the case where individual CTR elements are connected to the electronic component, and the cost can be reduced.

Specific Examples Hereinafter, as specific examples of the present invention, V ₇₅ Ge ₁₀ P ₅
A method for producing a sealing resin material, in which a CTR powder having a composition of Sr ₁₀ O _x is dispersed in a thermosetting epoxy resin,
A ceramic filter sealed using the sealing resin material will be described. Further, a ceramic filter sealed using a sealing resin material according to the conventional example was manufactured, and changes in the resonance frequency and the anti-resonance frequency in each of the ceramic filters of the example and the conventional example were measured.

First, an embodiment of the present invention will be described.
The CTR powder having the CTR function is composed of V ₂ O ₅ , (NH ₄ ) ₂ HPO ₄ , SrCO ₃ and G having a purity of 99.9% or more.
eO was used as the starting material. These raw materials are weighed and mixed in a predetermined ratio, melted red hot in a porcelain crucible, poured into water to form glassy pieces, heat-treated in a weak reducing atmosphere at 200 to 300 ° C., then pulverized again, and fixed The particles having a particle size or less were screened. This powder was used as a raw material CTR powder (V ₇₅ Ge ₁₀ P ₅ Sr ₁₀ O _x ).

An epoxy resin having a thermosetting temperature of 107 ° C. was used as the thermosetting resin serving as the base resin.

Then, 80 parts by weight of CTR powder and 20 parts by weight of epoxy resin were mixed, a ketone solvent was added as a curing agent, and silica was added as a filler, and simple mixing was performed by a stirring blade. A resin material for sealing was obtained.
Then, this sealing resin material was kneaded with a roll.

The piezoelectric ceramic plate used in the electronic component body is composed of (Pb _0.99 La _0.01 ) (Ti _0.50 Zr _0.50 ) O ₃ +0.2 wt% Cr ₂ O ₃ and has an electrode formed by baking Ag paste on the surface. A pattern is formed and polarized.
The piezoelectric ceramic plate, the external terminals, and the terminals for internal connection were alternately arranged to form an electronic component body (ladder type filter).

The external terminals of this electronic component body were inserted into the through holes of the bottom lid, the electronic component body was housed in the case body whose bottom surface was opened, and the bottom surface opening of the case body was closed by the bottom lid to manufacture a ceramic filter. Then, the above-mentioned sealing resin material was applied to the through-holes through which the external terminals of the bottom lid were drawn out. At this time, sealing was performed so that the external terminals were connected by a sealing resin material having a CTR function. Then, the resin material for sealing was cured in a 120 ° C. temperature bath.

Conventional Example On the other hand, as a conventional example, 100 parts by weight of a sealing resin material containing no CTR powder is prepared, and the same electronic component body as that of the embodiment is housed in the same case. The through hole was sealed under the same conditions as in the example.

Measurement Results The ceramic filter of the example thus produced and the ceramic filter of the conventional example were placed in a temperature bath at 250 ° C. for 3 minutes for heat treatment, taken out from the temperature bath, and then left at room temperature for 2 hours. did. The variation ΔFr of the resonance frequency before and after the heating and the variation ΔFa of the anti-resonance frequency at this time were examined for the example and the conventional example, respectively.
The measurement results are shown in Table 1.

[0023]

[Table 1]

As can be seen from Table 1, according to the present embodiment, the resonance / resonance of the ceramic filter is
Both the frequency changes ΔFr and ΔFa of the anti-resonance frequency could be made extremely small.

Although the above-mentioned embodiment shows the case where it is applied to the ceramic filter, the present invention can be applied to all electronic parts sealed with the resin material for sealing. For example, when used for a ceramic oscillator,
By sealing with a sealing resin material having a CTR function, it is possible to prevent the oscillation frequency from changing even after a high temperature load such as soldering. As for various other types of electronic components, it is needless to say that by using a sealing resin material having a CTR function, the electronic component main body can be prevented from characteristic deterioration after high temperature loading.

Further, even if a piezoelectric material, which has been excellent in piezoelectric characteristics and could not be used because its insulation resistance is too high, can be reduced by a high temperature load by sealing with a sealing resin material having a CTR function. You can prevent poles.

[0027]

According to the present invention, in an electronic component in which an electronic component main body is housed in a plastic or metal case, by sealing the lead-out portion of the external terminal with a sealing resin material having a CTR function, It is possible to obtain a multifunctional electronic component having both the original function of the component and the CTR function.

As a result, it is possible to remove charges such as pyroelectric charges generated from the electronic component body and a high voltage load due to the charges by the resin material for sealing.

Therefore, the life of the electronic component can be remarkably extended. In addition, since the resin material having the CTR function can protect the electronic component body from a high voltage load and the like, there is an advantage that the range of selection of the material used for the electronic component body can be widened.

[Brief description of drawings]

FIG. 1 is a sectional view showing a ceramic filter according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of a conventional ceramic filter.

3 (a) and 3 (b) are explanatory views showing a mechanism of generating a pyroelectric charge on a piezoelectric ceramic plate.

[Explanation of symbols]

 11 Ceramic Filter 12 Case 13 Case Body 14 Bottom Lid 16 Piezoelectric Ceramics Plate 17 External Terminal 19 Through Hole 20 Resin Material for Sealing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tachibana ▲ Taka ▼ Toshihiko 2-26-10 Tenjin Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. An electronic component in which an electronic component body is housed in a case such as a plastic case or a metal case, wherein a through hole of the case into which an external terminal is inserted is sealed with a resin material having a sudden change thermistor function. Electronic components to do.