JPH09161539A - Conductive compound and ceramic electronic parts using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conductive compound in which the high bonding strength between a board and an electrode can be held even if coating process is applied by containing a glass flit made of silver powder, BiO2 , MO, and RO and organic vehicle. SOLUTION: A conductive compound contains a glass flit made of silver powder with its unlimited shape, its particulate diameter, etc., SiO2 , MO (however, M contains Ba or contains Ba and at least one of Zn and Pb), and RO (however, R contains alkali earth metal or at least one of alkali earth metals excluding Ba) and contains an organic vehicle for pasting these components. For MO, BaO is a mandatory component, and an effect for reducing elution to the coating liquid of the glass flit is made significant by arranging it in the range of 15 to 60 pts.wt. toward SiO2 100 pts.wt.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a conductive composition.

[0002]

2. Description of the Related Art Conventionally, a thick film electrode of a ceramic electronic component has been prepared by applying a conductive composition obtained by forming a conductive powder and a glass frit into a paste with an organic vehicle onto a substrate by screen printing or the like and drying the composition. , Is formed by baking.

By the way, lead silicate, zinc silicate or the like was used for this glass frit. In this case, lead or zinc in the glass frit is used as a complexing agent in the plating solution, especially diammonium hydrogen citrate. Since it is eluted, there is a problem that the electrode strength after plating deteriorates.

Therefore, in order to solve the above problems, the following methods have been considered. (1) Change the complexing agent to one that does not dissolve the glass component.

(2) A glass frit for forming a chemical reaction layer (chemical bond) with a ceramic dielectric layer,
Alternatively, an inorganic binder is used.

[0006]

However, the conventional method has the following problems. That is, in the case of (1), it is necessary to reexamine the type of the plating liquid itself, which is not cost effective. In the case of (2), the technical difficulty is high and the versatility is poor.

An object of the present invention is to provide a conductive composition capable of maintaining a high bonding strength between a substrate and an electrode even if it is plated.

[0008]

The present invention has completed a conductive composition in order to solve the above problems. The conductive composition of the present invention comprises (A) silver powder and (B)
SiO ₂ , MO (provided that M contains Ba, or B
a glass frit containing a and containing at least one of Zn and Pb), and RO (wherein R contains at least one of an alkali metal or an alkaline earth metal other than Ba). , (C) organic vehicle.

Further, in the conductive composition of the present invention,
The glass frit of (B) may contain Al ₂ O ₃ .

Further, in the conductive composition of the present invention,
The glass frit of (B) may contain B ₂ O ₃ .

Further, in the conductive composition of the present invention,
If the compounding amount of the composition in the glass frit of (B) is limited, it is preferable to contain 1 to 60 parts by weight of Al ₂ O ₃ with respect to 100 parts by weight of SiO ₂ .

Further, in the conductive composition of the present invention,
If the compounding amount of the composition in the glass frit of (B) is limited, 1 part of B ₂ O ₃ is added to 100 parts by weight of SiO _2.
It is preferable that the content is from about 60 parts by weight.

[0013] In the conductive composition of the present invention,
If the compounding amount of the composition in the glass frit of (B) is limited, the total compounding amount of the metal oxide contained as MO is within the range of 15 to 60 parts by weight with respect to 100 parts by weight of SiO ₂ . Is preferred.

Further, in the conductive composition of the present invention,
If the amount of the composition in the glass frit of (B) is limited, the total amount of the metal oxides contained as RO is in the range of 14 to 30 parts by weight with respect to 100 parts by weight of SiO ₂ . Is preferred.

Further, the ceramic electronic component of the present invention is characterized by including a ceramic element body and a thick film electrode obtained by baking the above-mentioned conductive composition on the ceramic element body.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The conductive composition of the present invention comprises (A) a silver powder and (B) SiO ₂ , MO (where M is Ba, or contains Ba and contains at least one of Zn and Pb). And a RO (wherein R contains at least one of an alkali metal or an alkaline earth metal other than Ba), and
(C) Organic vehicle. Therefore, the thick film electrode formed by baking these components can maintain a high bonding strength between the substrate and the electrode even if the plating process is performed.

(A) Used in the Conductive Composition of the Present Invention
The silver powder is not particularly limited in shape, particle size, etc. of the silver powder. For example, any shape such as a spherical shape or a flat shape can be used, and of course, different shapes may be mixed and used.

(B) used in the conductive composition of the present invention
The glass frit is a component for firmly bonding the baked thick film electrode and the ceramic body when the conductive composition of the present invention is used for manufacturing a ceramic electronic component, for example.

This glass frit is, as described above,
SiO ₂ , MO (provided that M contains Ba, or B
a and containing at least one of Zn and Pb), and RO (provided that R contains at least one of an alkali metal or an alkaline earth metal other than Ba). .

With respect to MO, by adding BaO as an essential component, the effect of reducing the elution of the glass frit into the plating solution becomes remarkable. In addition,
RO is not particularly limited as long as it is Li, Na, K, Ca or the like.

Further, this glass frit may be blended with Al ₂ O ₃ for improving plating resistance, or
B2O3 may be added to lower the softening point of the glass. Also in this case, in the glass frit component, S
The composition is such that the compounding ratio of iO ₂ is the highest.

Next, the composition ratio of the glass frit will be described. In MO, it is preferable that the total amount of the metal oxides contained as MO be within the range of 15 to 60 parts by weight with respect to 100 parts by weight of SiO ₂ . If the blending amount is less than 15 parts by weight, the softening point of the glass becomes high, which is not preferable. On the other hand, when it exceeds 60 parts by weight, the glass frit is eluted into the plating solution, and the electrode strength deteriorates after the plating treatment, which is not preferable.

More preferably, the total amount of metal oxides contained as MO is in the range of 15 to 60 parts by weight and the amount of ZnO or PbO is less than 10 parts by weight. For example, when ZnO is contained as MO, it has been confirmed by experiments that the amount of elution increases with a large amount of compounding.

It is more preferable that the total amount of MO compounded is within the range of 19 to 52 parts by weight, as shown in the examples.

Further, in the RO, it is preferable that the total amount of the metal oxides contained as RO is in the range of 14 to 30 parts by weight with respect to 100 parts by weight of SiO ₂ . In the case of an alkali metal oxide, if the content is less than 14 parts by weight, the working temperature of the glass frit becomes high, which is not preferable. On the other hand, when it exceeds 30 parts by weight, the water resistance of the glass frit is deteriorated, which is not preferable. Further, in the case of an oxide of an alkaline earth metal, if it is less than 14 parts by weight, the stabilization of the glass frit is poor and it is not preferable. On the other hand, if it exceeds 30 parts by weight, the softening temperature of the glass frit becomes high, which is not preferable. In addition, more preferably, as shown in the embodiment, 28-
Within the range of 30 parts by weight.

When Al ₂ O ₃ is contained, it is preferable to contain 1 to 60 parts by weight with respect to 100 parts by weight of SiO ₂ . If the content exceeds 60 parts by weight, vitrification becomes difficult and the softening temperature becomes high, which is not preferable. In addition, more preferably, it is within the range of 9 to 26 parts by weight as shown in the examples.

When B ₂ O ₃ is contained,
It is preferable to contain 1 to 60 parts by weight with respect to 100 parts by weight of SiO ₂ . If the content exceeds 60 parts by weight, the glass frit is eluted into the plating solution and the electrode strength deteriorates after the plating treatment, which is not preferable. It has been confirmed by experiments that the amount of B ₂ O ₃ eluted increases as the blending amount increases. In addition,
More preferably, it is in the range of 15 to 20 parts by weight as shown in the examples.

The amount of the above glass frit used may be changed according to the article using the conductive composition of the present invention, and therefore it is not necessarily limited, but for example, the conductive composition of the present invention is ceramic. When it is used for producing an oscillator, it is preferably contained in an amount of 2 to 10 parts by weight based on 100 parts by weight of the silver powder in the conductive composition of the present invention.
When the amount used is less than 2 parts by weight, the adhesion strength between the electrode and the ceramic deteriorates, which is not preferable. on the other hand,
If it exceeds 10 parts by weight, the plating property is deteriorated, which is not preferable.

(C) used in the conductive composition of the present invention
The organic vehicle is a component for making the components of the above (A) silver powder and (B) glass frit into a paste, and such an organic vehicle is not particularly limited. As a preferred specific example, for example, ethyl cellulose resin, alkyd resin and the like are used as resin components, and terpene solvent, glycol solvent and the like are used as organic solvents, and the concentration of the resin component is 5 to 1
For example, it may be dissolved to 0%.

The amount of the organic vehicle used may be changed according to the article using the conductive composition of the present invention, and therefore it is not necessarily limited. For example, the conductive composition of the present invention is a ceramic. When used in the production of electronic parts, it is preferable to contain 30 to 150 parts by weight with respect to 100 parts by weight of silver powder in the conductive composition of the present invention. If the amount used is less than 30 parts by weight, it becomes difficult to form a paste, which is not preferable. On the other hand, if the amount exceeds 150 parts by weight, the silver powder is not well dispersed and appropriate conductivity cannot be obtained, which is not preferable.

The conductive composition of the present invention can be easily prepared by previously mixing the above-mentioned components, kneading them to form a paste.

When the conductive composition of the present invention thus produced is printed on a ceramic body and baked for plating, the amount of glass eluted into the plating solution can be reduced. Further, even in the tape peeling test, the tape has almost no peeling and has a bonding strength superior to that of the conventional one. Further, even if a tape peeling test is performed after the moisture resistance test, the tape is hardly peeled off and the bonding strength superior to that of the conventional one is maintained.

When a thick film electrode for a ceramic electronic component is produced using the conductive composition of the present invention, it may be used in the same manner as the conventional method using the conductive composition. After screen-printing the paste obtained as described above on a ceramic body and drying at 100 to 200 ° C. for 3 to 10 minutes, 10 to 750 to 900 ° C.
The baking may be performed for 20 minutes.

The ceramic electronic component manufactured as described above can greatly improve the electrode strength after the plating treatment without deteriorating the characteristics of the electronic component.

Next, the present invention will be described more specifically based on examples, but the present invention is not limited to only these examples.

[0036]

EXAMPLES Hereinafter, the case where the conductive composition of this example is used for a piezoelectric electronic component which is a ceramic electronic component will be described. FIG. 1 is an exploded perspective view showing a schematic structure of a piezoelectric electronic component. As shown in FIG. 1, a strip-shaped piezoelectric vibrator 2 having vibrating electrodes 1 formed on opposing main surfaces, and end portions 2a of the piezoelectric vibrator 2 are sandwiched and bonded from the main surface side. Thus, the piezoelectric vibrating body 4 integrally formed with the pair of holding frame bodies 3 that vibratably supports the central portion 2b, and the pair of case bodies 5 that sandwich and store the piezoelectric vibrating body 4 are configured. There was something that was done. And
Each of the holding frame bodies 3 is made of a ceramic material such as alumina, and by facing the main surface of the piezoelectric vibrator 2 made of piezoelectric ceramic obtained by sintering a metal oxide. , The opening 3a serving as a vibration space
Is formed into a "U" shape in a plan view.

Each of the case bodies 5 is made of a ceramic material or an insulating resin material, and a concave portion 5a for ensuring the vibration of the piezoelectric vibrator 2 is formed on the inner surface thereof. Further, each of the vibrating electrodes 1 formed on the main surface of the piezoelectric vibrator 2 has the piezoelectric vibrator 2
Of the vibrating electrodes 1 extending to different end portions 2a of each other, and lead electrodes (not shown) formed on different end surfaces of the case body 5 sandwiching the piezoelectric vibrating body 4 and being bonded to each other. It is conductive by being connected to each.

The vibrating electrode 1 of such a piezoelectric electronic component is a thick film electrode made of a sintered film formed by baking the conductive composition according to the present invention.

Next, the conductive composition according to the present invention will be described in detail. Table 1 shows Examples 1 to 3 which are the present examples.
The composition ratio (unit: parts by weight) of the glass frit of the conductive composition of Table 1 and Table 2 show the elution amount of the glass frit (unit: μg). As comparative examples, Table 1 and Table 2 show the composition ratios and elution amounts of Comparative Examples 1 to 3.

[0040]

[Table 1]

[0041]

[Table 2]

Here, a method of measuring the elution amount of the glass frit will be described. First, this paste-like glass frit (glaze frit) was screen-printed on a ceramic substrate. Next, this printed board was baked at 810 ° C. Then, 50 ml of 110 g / l complexing agent (diammonium hydrogen citrate) was placed in a beaker and kept at 35 ° C. in a constant temperature bath, and two of the above-mentioned printed boards were placed therein for 60 minutes. I left it. After 60 minutes, the substrate was taken out and the complexing agent solution after taken out was subjected to atomic absorption and ICP-A.
The ES amount of the glass component was quantified by ES.

Next, Table 3 shows Example 1 of this example.
The composition ratios of the conductive compositions of 1 to Example 1-3 and Example 2-1 and the number of electrode peelings when used for the vibrating electrode of the piezoelectric electronic component will be shown. As Comparative Examples, Table 3 also shows Comparative Examples 2-1 and 3-1. Here, Example 1-1 to Example 1-3 are shown in Table 1.
Example 2 in which the glass frit of Example 1 is used.
-1 uses the glass frit of Example 2 in Table 1. Further, Comparative Example 2-1 uses the glass frit of Comparative Example 2 in Table 1, and Comparative Example 3-1 uses the glass frit of Comparative Example 3 in Table 1.

[0044]

[Table 3]

In this embodiment, 100 parts by weight of spherical silver powder having an average particle size of 1 to 5 μm is used as the silver powder.

As the organic vehicle, ethyl cellulose resin and alkyd resin having a resin component concentration of 8% are used.
Thus, 45 parts by weight of the organic vehicle dissolved in the terpene solvent is used for 100 parts by weight of the silver powder.

Here, a method of measuring the number of peeled electrodes of the piezoelectric electronic component will be described. First, the conductive composition was screen-printed as a vibrating electrode for a piezoelectric electronic component. Next, this printed board was baked at 810 ° C. Then, the complexing agent (diammonium hydrogen citrate) solution was brought to 40 ° C., and the baked substrate was immersed for 60 minutes. Next, the tape was attached to the silver electrode film, and after the tape was peeled off, it was examined whether or not the electrode was peeled off.

In each of Examples 1-1 to 1-3, no sheet was peeled off, which was good. Example 2
-1 was slightly peeled off, but there was no problem in practical use. on the other hand,
In Comparative Example 2-1, all were peeled off and defective. Also,
Most of Comparative Example 3-1 was peeled off and was defective.

Next, Table 4 shows Example 1 of this example.
The number of electrode peelings after the moisture resistance test when 1 to Example 1-3 are used for the vibration electrode of the piezoelectric electronic component will be shown. As a comparative example, Table 4 also shows the case of Comparative Example 3-1.

[0050]

[Table 4]

Here, a method of measuring the number of peeled electrodes of the ceramic oscillator after the humidity resistance test will be described. First, the conductive composition was screen-printed as a vibrating electrode for a piezoelectric electronic component. Next, this printed board was baked at 810 ° C. And a humidity resistance test (121 ° C, 2 atm, 100%
RH, left for 20 hours). Next, the tape was attached to the silver electrode film, and after the tape was peeled off, it was examined whether or not the electrode was peeled off.

Each of Examples 1-1 to 1-3 was good without peeling off one sheet. On the other hand, Comparative Example 3
Most of -1 was peeled off and was defective.

[0053]

EFFECTS OF THE INVENTION By using the conductive composition of the present invention, it is possible to reduce the amount of glass eluted into the plating solution even after the plating treatment at the time of forming electrodes, and to maintain excellent electrode bonding strength.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a schematic structure of a piezoelectric electronic component in which a thick film electrode is formed using the conductive composition of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibrating electrode 2 Piezoelectric vibrator 2a End part 2b Central part 3 Holding frame body 4 Piezoelectric vibrating body 5 Case body 5a Recessed portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Sugimura 2-26-10 Tenjin Tenjin, Nagaokakyo-shi, Kyoto Stock Company Murata Manufacturing Co., Ltd. (72) Toru Ebuchi 2-26-10 Tenjin Tenjin, Nagaokakyo, Kyoto Murata Manufacturing Co., Ltd.

Claims (8)

[Claims] 1. (A) Silver powder and (B) SiO ₂ , MO
(Provided that M contains Ba, or contains Ba and contains at least one of Zn and Pb), and RO (provided that R is an alkali metal or an alkaline earth metal other than Ba). A conductive composition comprising: a glass frit (containing at least one kind); and (C) an organic vehicle. 2. The glass frit of (B) is made of Al ₂
The electrically conductive composition according to claim 1, which contains O ₃ . 3. The glass frit of (B) is B ₂ O ₃
The conductive composition according to claim 1 or 2, further comprising: 4. The glass frit of (B) above is the S
The electrically conductive composition according to claim 2, which contains 1 to 60 parts by weight of Al ₂ O ₃ with respect to 100 parts by weight of iO ₂ . 5. The glass frit of (B) above is the same as the S
The electrically conductive composition according to claim 3, which contains 1 to 60 parts by weight of B ₂ O ₃ with respect to 100 parts by weight of iO ₂ . 6. The glass frit of (B) above is the S
The conductive composition according to any one of claims 1 to 5, wherein MO is contained in an amount of 15 to 60 parts by weight with respect to 100 parts by weight of iO ₂ . 7. The glass frit of (B) above is the S
The conductive composition according to any one of claims 1 to 6, which contains 14 to 30 parts by weight of RO with respect to 100 parts by weight of iO ₂ . 8. A ceramic electron comprising a ceramic body and a thick film electrode obtained by baking the conductive composition according to any one of claims 1 to 7 on the ceramic body. parts.