JPS6134203B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a baking-type conductive paste containing nickel as a main component, and more particularly to wiring, terminals, etc. inside or outside of a multilayer ceramic circuit device.
The present invention relates to a baking-type conductive paste suitable for forming conductors such as electrodes by co-firing with ceramic green sheets. To increase the degree of integration of multilayer ceramic circuit devices, thick film capacitors, thick film resistors, etc. have been formed on the exposed surfaces of multilayer ceramic bodies. Conventionally, the conductors of such multilayer ceramic circuit devices have been formed using a baking-type conductive paste mainly composed of silver (70%) and palladium (30%). However, since silver-palladium paste contains 30% palladium, which has a high specific resistance, when it is sintered into a conductor, its sheet resistance is as high as 62.5 μΩcm. Furthermore, silver palladium paste was expensive. For this reason, attempts have been made to form electrodes using pastes of base metals such as nickel. However, it has been impossible to form a conductor with desired characteristics simply by making a paste of nickel powder. That is, it is desirable that the conductive paste for forming the internal and external conductors of the multilayer ceramic circuit device satisfies the following conditions. (1) It must be able to be sintered at a temperature of approximately 1100 to 1400°C because it is fired simultaneously with the ceramic body (1100 to 1400°C). (2) After forming a conductor through the treatment in (1), a thick film capacitor or a thick film resistor is further formed on the top surface, so even if heat treatment is performed at 1000°C in an atmospheric atmosphere (oxidizing atmosphere), the resistivity remains low. Don't go up. (3) Even after the same firing and heat treatment as in (2), the tensile strength of the conductor is 1Kg/mm ² or more. However, a conductive paste based on nickel that satisfies the above conditions does not yet exist. Therefore, an object of the present invention is to provide a reducing or neutral atmosphere baking type conductive paste that satisfies the above conditions. The first invention of the present application to achieve the above-mentioned object is a powder of 70 to 98% by weight of nickel, a powder of manganese or a manganese compound having a manganese content of 0.05 to 29.9% by weight in terms of MnO, and 0.1% by weight of manganese or a manganese compound. ~20% by weight of the glass frit, and the total of the nickel powder, the MnO, and the glass frit is 100% by weight.
The present invention relates to a sinterable conductive paste characterized by containing a suitable amount of vehicle. According to the above invention, due to the action of manganese or this compound, the resistivity is 25 μΩcm or less and the tensile strength is 1.
It is possible to provide a conductive paste that can obtain a conductor of Kg/mm ² or more. The second invention of the present application further adds nickel silicide or zirconium boride to the paste of the first invention, so that the resistivity does not increase even when heat treatment is performed at 1050°C in an air atmosphere. This is what I did. Next, examples of the present invention will be described. Example 1 Ni powder with an average particle size of 10μ, MnO with an average particle size of 5μ
Powder, SrO-SiO ₂ -PbO glass frit with an average particle size of 3 μm (melting point 1000°C) was weighed and blended in the proportions shown in Table 1, and 6 parts by weight of ethyl cellulose and α- 33 parts by weight of terpineol was added as a vehicle and kneaded in a three-roll mill to prepare conductive paste samples. Next, 50 parts by weight of Al ₂ O ₃ powder, 20 parts by weight of SiO ₂ powder,
25 parts by weight of SrO powder, 1 part by weight of Li ₂ O powder and MgO
4 parts by weight of powder, a water-soluble binder made of acrylic acid ester polymer, glycerin, condensed phosphate, and water were added, mixed in a ball mill to create a slip, and after defoaming, the slip was thickened by a doctor blade method. A green sheet with a thickness of 50μ was prepared. After drying, it was punched out into a rectangular shape using a press. The conductive paste described above was applied to this green sheet in the pattern shown in Figure 1 using a 280-mesh screen, dried at 125°C for 10 minutes, four sheets were stacked and bonded by thermocompression, and then placed in an air atmosphere. 900 at
The binder is blown off by heat treatment at ℃, and N ₂ (98.5%) +
Baked at 1200℃ for 2 hours in an atmosphere of H ₂ (1.5%),
Next, heat treatment at 1000° C. for 30 minutes in an air atmosphere was repeated five times to produce a sample consisting of the porcelain 1 and the conductor 2 shown in FIGS. 1 and 2. Next, between 2a and 2b of conductor 2 of each layer (width 0.2mm, thickness 15μ, length
When the resistance value of 20 mm) was measured using a resistance bridge and the average resistivity (ρ) was calculated, the results shown in Table 1 were obtained. Note that the resistance of the inner layer was measured using a previously provided through hole (not shown). In addition, the same green sheet as above was punched out into a rectangular shape, the above-mentioned conductive paste was similarly printed in the center of the green sheet, and the above-mentioned conductive paste was printed in the same manner as above, and the porcelain 3 and conductor 4 were formed as shown in Figs. 3 and 4. After sintering, a ring-shaped end of a 0.6 mm copper wire 5 was attached to a 2 mm square conductor 4 by 30 mm as shown in Figure 4.
When the tensile strength (T) was measured by attaching a spring meter to the copper wire 5, the results shown in Table 1 were obtained. In Tables 1 to 6, the sample for measuring resistivity ρ and the sample for measuring tensile strength T are different samples, but since the porcelain and conductor are the same,
The same sample number is assigned and shown in the same column.

【table】

[Table] As is clear from Table 1, MnO is 0.05 to 29.9
By adding within the weight% range, ρ can be reduced to 25 μΩ.
It becomes possible to form electrodes or conductors with a T of 1 Kg/mm ² or more on porcelain. In other words, it is possible to obtain a conductor with a resistivity ρ significantly lower than that of a conventional silver-palladium electrode (62.5 μΩcm). Note that if MnO is less than 0.05% by weight, oxidation of the Ni particles cannot be prevented, and the tensile strength T becomes less than 1 Kg/mm ² . Furthermore, when MnO exceeds 29.9% by weight, the resistivity exceeds 25 μΩcm. Therefore, MnO is 0.05~29.9
It is desirable to keep it in the range of % by weight. Furthermore, if the glass frit content is less than 0.1% by weight, there will be no addition effect and T will be less than 1Kg/ ^mm2 ,
When it exceeds 20% by weight, ρ exceeds 25μΩcm. Therefore, it is desirable that the amount of glass frit be in the range of 0.1 to 20% by weight. Therefore, sample numbers 1, 10, and 14 are outside the scope of the present invention. Example 2 A paste with the composition shown in Table 2 was prepared in the same manner as in Example 1 except that the MnO powder in Example 1 was changed to Mn powder, and the same measurements as in Example 1 were carried out. The results were obtained.

【table】

[Table] As is clear from Table 2, the same effects as MnO powder can be obtained using Mn powder. still
The preferred range of Mn is 0.04-24.83% by weight;
If this is converted to MnO, it falls within the range of 0.05 to 29.9% by weight. In Table 2, sample numbers 15, 24, and 26 are outside the scope of the present invention. Example 3 Ni powder with an average particle size of 1 μm was used instead of the 10 μm Ni powder in Example 1, and PbO-BaO-SiO ₂ glass powder (melting point 800) was used as the glass frit.
A paste having the composition shown in Table 3 was prepared in exactly the same manner as in Example 1, except that 100.degree. C.) was used, and the same measurements were carried out, and the results shown in Table 3 were obtained.

【table】

[Table] As is clear from Table 3, the same effects as in Example 1 can be obtained even if the particle size of the Ni powder is changed or the type of glass frit is changed. In Table 3, sample numbers 29, 37, and 39 are outside the scope of the present invention. Example 4 A paste was made in the same manner as in Example 3 except that MnO ₂ powder was used instead of the MnO powder in Example 3, and ρ and T were measured, and the results shown in Table 4 were obtained.

[Table] As is clear from Table 4, the same effects as in Examples 1 to 3 can be obtained even when MnO ₂ is used. The preferred range of MnO ₂ is this amount of Mn.
It is 0.05 to 29.9% by weight in terms of MnO. Moreover, sample numbers 41 and 48 in Table 4 are outside the scope of the present invention. Example 5 The main ingredients were Ni, MnO, and glass frit in Example 1, and NiSi ₂ (nickel silicide) with an average particle size of 10 μm was added to 100 parts by weight of the main ingredients as shown in Table 5. A paste was made in the same manner as in Example 1, and ρ and T were measured in the same manner, and the results shown in Table 5 were obtained. However, heat treatment in an air atmosphere was performed at 1050°C, which is 50°C higher than 1000°C in Example 1, for 30 minutes.
This was repeated 5 times for 5 minutes.

【table】

【table】

[Table] As is clear from this Table 5, NiSi ₂ is 0.05
If added in an amount of ~25% by weight, it will be effective in an air atmosphere.
Even after heat treatment at 1050°C, ρ can be kept at a low value. This is because NiSi ₂ reacts with oxygen and decomposes to prevent oxidation of the Ni particles. However, if it is less than 0.1 part by weight, it has no effect. 25 again
If the amount exceeds the weight part, sinterability deteriorates and a dense conductor cannot be obtained. Therefore, the preferred range of _NiSi2 is
It is 0.05 to 25 parts by weight. Therefore, in Table 5, sample numbers 49-54, 60, 66, 72, 78, 84, 85-90, 96
is outside the scope of this invention. Furthermore, it was impossible to measure ρ and T for those with poor sinterability. Example 6 A paste was prepared in the same manner as in Example 5 by adding ZrB ₂ (zirconium boride) as shown in Table 6 instead of NiSi ₂ in Example 5, and ρ and T were measured in the same manner. The results shown in 6 tables were obtained.

【table】

[Table] As is clear from this Table 6, ZrB ₂ is
Even if 25 parts by weight is added, the same effect as in Example 5 can be obtained. In Table 6, sample numbers 97, 101, 102, 106,
107, 111 are outside the scope of this invention. Furthermore, it was impossible to measure ρ and T for those with poor sinterability. Example 7 A ceramic green sheet was prepared in the same manner as in Example 1 using a material in which 1% by weight of clay was added to CaTiO ₃ powder, and a conductive paste according to the present invention (85% by weight of Ni powder, 7.5% by weight of Mn powder) , PbO−
7.5% by weight of BaO-SiO glass frit and binder) were prepared, and the paste 8 was screen printed on the green sheet 7 as shown in Figures 5 and 6, and the sheets were stacked in four layers, alternating each other. , further layer only the green sheet on top of this,
Thermocompression bonded at 1280℃ for 4 hours with N ₂ (98.5%) + H ₂
(1.5%) in a reducing atmosphere. after that
After heat treatment at 1000°C for 1 hour in an air atmosphere to compensate for the reduced portion of the dielectric, an In-Ga electrode was formed on the side surface of the sintered body. Then, the capacitance and tan δ were measured using Yokogawa Manufacturing Model YHP4270-A, and the dielectric constant (ε _s ) was determined from the measured capacitance. Also,
Insulation resistance (IR) was measured after applying DC100V for 60 seconds. As a result, the results shown in Table 7 were obtained. For comparison, a comparative sample was prepared by changing the conductive paste of this example to a silver-palladium conductive paste and firing at 1280°C for 4 hours in an air atmosphere. When the relative dielectric constant (ε _s ), tan δ, and insulation resistance (IR) were measured in exactly the same manner as above, the results shown in Table 7 below were obtained.

[Table] From the results, it was confirmed that the conductive paste of the present invention has almost the same effect as the silver-palladium paste, and can also be used as an internal electrode of a multilayer capacitor.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the porcelain and electrodes according to Example 1 of the present invention, FIG. 2 is a front view of FIG. 1, and FIG.
The figure is a plan view of the sample for measuring T in Example 1, FIG. 4 is a cross-sectional view showing the measurement state of T, FIG. The figure is a front view of FIG. 5. In the symbols used in the drawings, 1 is porcelain and 2 is a conductor.

Claims (1)

[Claims] 1. Nickel powder of 70 to 98% by weight, and manganese amount of 0.05 to 29.9% by weight converted to MnO.
a powder of manganese or a manganese compound, and 0.1 to 20% by weight of glass frit, so that the total of the nickel powder, the MnO, and the glass frit is 100% by weight,
A baking-type conductive paste characterized by containing an appropriate amount of vehicle. 2 Nickel powder of 70-98% by weight and manganese amount of 0.05-29.9% by weight converted to MnO
a powder of manganese or a manganese compound, and 0.1 to 20% by weight of glass frit, so that the total of the nickel powder, the MnO, and the glass frit is 100% by weight, and the nickel powder, the MnO, and the glass frit are Contains 0.05 to 25 parts by weight of nickel silicide or zirconium boride based on 100 parts by weight in total with glass frit,
A baking-type conductive paste characterized by containing an appropriate amount of vehicle.