JPH0590006A - Composition for thick-film resistor formation - Google Patents

Abstract

PURPOSE:To provide a composition, for thick-film resistor formation wherein a change in its resistance value is small in a reheating process when a glass coating operation or the like is performed after a resistor has been formed on a ceramic substrate and a thick-film resistor cab formed at good yield. CONSTITUTION:A composition for thick-film resistor formation is composed mainly of the following: a conductive powder which contains RuO2 and at least either Ag or Pd; a glass powder; and an organic vehicle. The composition contains 40 to 70wt.% of either Ag or Pd or both of them in its solid portion and 30 to 60wt.% of RuO2 and glass. The weight ratio of RuO2 to glass is set within a range of 2:8 to 4:6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for forming a thick film resistor, particularly a low resistance resistor, on a ceramic substrate or the like in electronic circuit parts of various electronic devices.

[0002]

2. Description of the Related Art Conventionally, a conductive powder and a glass powder are mixed so as to have a required resistance value, and a paste prepared by dispersing this in an organic vehicle is applied onto a ceramic substrate such as alumina by a screen printing method or the like in a desired shape. Then 700-900
A thick film resistor as an electronic circuit component is formed on a substrate by firing at a temperature of ℃. In particular, it is known that the stability of the resistance value is improved by using RuO ₂ in addition to Ag and Pd as the conductive powder of the low resistance value resistor.

In the manufacturing process of, for example, a chip resistor using the thick film resistor as described above, the resistance value of the resistor is usually adjusted and then 600 ° C. for the purpose of glass coating or the like.
A degree of reheating is performed. The resistance value is adjusted by trimming in consideration of the resistance value change in the reheating process.

[0004]

However, if there is a large change in the resistance value in the above reheating step, it becomes difficult to keep the final resistance value within the target range, which is a major cause of deterioration of the yield. There is. The present invention has been proposed in view of the above problems, there is little resistance value change in the reheating step, thick film resistor forming composition having mainly low resistance value that yields thick film resistors with good yield The purpose is to provide.

[0005]

In order to achieve the above object, the composition for forming a thick film resistor according to the present invention has the following constitution. That is, in a thick film resistor forming composition containing a conductive powder containing at least one of Ag and Pd and RuO ₂ , a glass powder and an organic vehicle as main components, one of Ag and Pd in solid content Alternatively, both of them are contained together in an amount of 40 to 70% by weight, RuO ₂ and glass in an amount of 30 to 60% by weight, and the weight ratio of RuO ₂ and glass is within the range of 2: 8 to 4: 6. And

[0006]

The above Ag and Pd may be either one or both of the single powders or the alloy powders of the both, and the ratio of Ag and Pd is not particularly limited, but the cost and the resistance are not limited. In terms of temperature coefficient, etc., Ag and P
It is preferable that the weight ratio to d is within the range of 80:20 to 40:60. The particle size of each of the above powders is
10 μm or less, preferably 5 μm or less is suitable. R
uO ₂ powder may be one normally used for thick film resistors,
The particle size is 1 μm or less, preferably 0.2 μm or less. The glass powder may be lead borosilicate type, lead aluminum borosilicate type, etc., which are used for ordinary thick film resistors, and the particle size is 10
It is desirable that the thickness is less than or equal to μm, preferably less than or equal to 5 μm.

In addition to the above-mentioned Ag, Pd, RuO ₂ and glass powder, MnO ₂ , Nb ₂ O ₅ and Sb ₂ conventionally used for reducing the TCR (temperature coefficient of resistance) are used.
There is no problem in adding O ₃ , TiO ₂ , CuO or the like. The organic vehicle may be one in which ethyl cellulose, methacrylate or the like is dissolved in terpineol, butyl carbitol or the like as in the conventional case.

In the present invention, the solid content, namely Ag, P
Of the total solid content of d, RuO ₂ and glass powder, one or both of Ag and Pd are combined and 4
The reason why the content is 0 to 70% by weight is that the resistance value becomes too high when it is less than 40% by weight, and the resistance value becomes too low when it exceeds 70% by weight. The ratio of RuO ₂ and glass is
It is important for reducing the change in resistance value at the time of reheating, which is the object of the present invention, and the weight ratio of RuO ₂ and glass is 2: 8 to.
4: was a 6 range, the weight ratio of RuO ₂ and glass 4: When the RuO ₂ larger than 6, the resistance value changes at the time of re-heating increases, RuO ₂ and the weight ratio of the glass 2 :
This is because when the RuO ₂ content is less than 8, the resistance value becomes too high.

[0009]

Example: Average particle diameters are 1.0 μm and 0.3 μm, respectively.
m, Ag powder of 0.1 μm or less, Pd powder, RuO ₂ powder, and glass powder having an average particle size of 1.5 μm (PbO is 5
5% by weight, 30% by weight of SiO ₂ , 10% by weight of B ₂ O ₃ and 5% by weight of Al ₂ O ₃ ) and added with a terpineol solution of ethyl cellulose and kneaded with a three-roll mill. A pesto having the composition shown in 1 was prepared.

Then, the AgPd paste is preheated at 850 ° C.
The resistance paste is screen-printed on a 96% alumina substrate on which an AgPd electrode is formed by baking at 150 ° C.
After drying in, the peak temperature (maximum temperature) is kept at 850 ° C. for 9 minutes and baked in a belt furnace for a total of 50 minutes,
A resistor having a size of 1 mm square and a thickness of 8 to 10 μm was formed. The initial resistance value after firing was measured with a digital multimeter.

Next, a black glass paste is printed on the above resistor so as to coat the resistor and dried,
Keep the peak temperature of 600 ℃ for 5 minutes for a total of 4
Baking in a belt furnace for 0 minutes. The resistance value after firing was measured, and the rate of change with respect to the initial resistance value was obtained. The results are shown in Table 1 below.

[0012]

As described above, according to the above-described embodiments of the present invention, the rate of change in resistance value due to reheating could be kept within the range of ± 2%.

[0014]

As described above, since the composition for forming a thick film resistor according to the present invention can minimize the change in resistance value due to reheating, the resistance value after reheating should be within a predetermined range. It is easy to store, and when the resistance value is adjusted by trimming or the like, the resistance value can be adjusted very easily, and the yield of products can be greatly improved.

Claims (1)

[Claims] 1. At least one of Ag and Pd and RuO ₂
In a composition for forming a thick film resistor, which contains a conductive powder containing and a glass powder and an organic vehicle as the main components, one or both of Ag and Pd in the solid content are combined to obtain 4
0 to 70% by weight, RuO ₂ and glass 30 to 60% by weight, and the weight ratio of RuO ₂ and glass is 2: 8 to 4:
The composition for forming a thick film resistor is characterized in that it is in the range of 6.