JPH0233807A - Metallized paste composition - Google Patents

Abstract

PURPOSE:To obtain a less expensive metallized paste by applying the constitution wherein an organic binder is included in a mixture containing the predetermined amount of a Cu powder, a CuO powder, a Mn compound and a glass powder to such an extent as suitable for obtaining a paste. CONSTITUTION:1 to 50 pts.wt. of a Cu powder (mean grain size: 2.4mum) and 100 pts.wt. of a Cu2O powder (mean grain size: 2.8mum) as a rest are mixed with 2 to 10 pts.wt. of a MnO powder (means grain size: 3.2mum) or Mn2O3 on the bases of conversion into MnO and 4 to 20 pts.wt. of a glass powder (mean grain size: 2.1mum). In addition, ethanol and olein acid are added thereto and the solidified portion thereof is crushed. An organic binder comprising ethyl cellulose completely solved into butyl carbithol acetate is added to such an extent as suitable for obtaining a paste. According to the aforesaid constitution, it is possible to reduce the cost of a metallized paste and it is easy to remove an organic binder. Also, the properties of Cu become stable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a metallizing paste composition used for printing electrodes and wiring patterns on ceramic wiring boards.

[Prior Art] A metallizing paste composition for a ceramic wiring board consists of a gold B particle component that imparts conductivity, an adhesive component to the substrate, and an organic binder component that imparts physical attributes as a paste. . Conventionally, noble metal particles such as silver, silver-palladium, gold, and platinum have been used as the total refractive particle component in the metallization paste in order to prevent oxidation during baking of the substrate. In addition, glass powder is used as the adhesive component, and a resin, a solvent, a dispersant, etc. is used as the organic binder.

The conventional metallizing paste using noble metal powder as the total bending powder component has the advantage that the wiring board can be fired in the atmosphere, but because the noble metal is used as the conductive material, the price fluctuation is large and it is expensive. was there.

In order to solve these problems, a metallized base 1-1 so-called copper paste has also been proposed in which copper powder is used as the conductive particles. Copper was noted for its low cost compared to precious metals, its second-lowest electrical resistance after silver, and its resistance to migration, which led to the adoption of a method of firing wiring boards in a non-oxidizing atmosphere. As a result, it is used as a metallizing paste for ceramic wiring boards.

[Problems to be solved by the invention] However, such copper paste has the following two problems.

For one thing, although the copper material itself is cheaper than precious metals, it is suitable for metallizing paste materials.
Spherical particles are not easily obtained and are expensive. this is,
Copper powder obtained by the chemical precipitation method, which is a common method for producing spherical copper powder, is a fine powder, but the production efficiency is low, and even if a lot of time and effort are spent, only a small amount can be produced. It's for a reason.

Another problem is that it is difficult to completely remove the organic binder component used in the metallizing paste in a non-oxidizing atmosphere, and it is said that it does not decompose thermodynamically, especially at temperatures below the melting point of copper.

Therefore, in the process of baking the wiring board, delicate atmosphere control is required, such as including a small amount of oxygen in the non-oxidizing atmosphere, and the baking conditions are extremely difficult.

An object of the present invention is to provide a metallizing paste composition that can solve these problems.

[Means for solving the problem] That is, the gist of the means adopted in the present invention in order to achieve the above object is to use a copper component powder consisting of 1 to 50 parts by weight of metallic copper powder and the remainder being cuprous oxide. 100 parts by weight, and 2 to 10 parts by weight of manganese compound powder in terms of manganese monoxide.
This is a metallizing paste composition characterized in that it contains 4 to 20 parts by weight of glass powder, and m of an lv machine binder suitable for paste formation.

[Example] Next, examples of the present invention and usage examples thereof will be specifically described below.

(Example 1) Cuprous oxide (Cu20) powder (average particle size 2.8 μm
) 80g and metallic copper (Cu) powder (average particle size 2.4μm
>20g, -4g of manganese oxide (MnO) powder (average particle size 3.2μm), and glass powder (G made by Nippon Electric Glass Co., Ltd.)
A-12, average particle size 2.1 μm)] Og, 200 ml of ethanol, and 0.5 g of oleic acid (dispersant) were weighed and mixed in a ball mill for 16 hours. Then, the mixture was heated and dried to evaporate the ethanol,
The solid content was crushed to obtain a mixed powder.

Separately, 100g of butylcarpitol acetate
- 12 g of ethyl cellulose was put into the solution, heated to a temperature of 70° C. while stirring to completely dissolve the ethyl cellulose, and then naturally cooled to room temperature to prepare an organic binder.

100 g of the mixed powder, 25 g of the organic binder, and 0.5 g of oleic acid were mixed in a dish crusher, and then kneaded in a three-roll mill to produce a metallized paste.

Next, using the paste, separate alumina substrates (vertical 5
0111% width 120cm, thickness 0.8mm) on top, -
A square pattern with a side of 1.5 mg, a square pattern with a side of 8 cm, and multiple linear patterns with a width of 0, 31 m and a length of 100 mm were screen printed, and these were printed as 1.
It was dried for 10 minutes at a temperature of 20°C. The coating thickness of the metallized paste after drying was approximately 35 μm.

Next, the alumina substrate was heated to a maximum temperature of 880°C in the atmosphere.
The metallizing paste was passed through a mesh belt type tunnel furnace for a total time of 50 minutes to burn and scatter the binder components contained in the metallizing paste. Furthermore, N2 gas 96%-
The alumina substrate was introduced into a Metschbelt tunnel furnace maintained in a reducing atmosphere by supplying a mixed gas of 4% H2 gas at a flow rate of 4 m/hour, and the alumina substrate was heated from room temperature to 9 m/h.
The temperature was increased at a temperature gradient of 30°C/min to 50°C, followed by 95°C.
After maintaining the temperature at 0℃ for 30 minutes, return to room temperature for 3 minutes.
The metallization paste was fired using a temperature profile in which the temperature was lowered at a temperature gradient of 0° C./min.

Using the board on which the copper pattern has been formed according to the above procedure, the adhesion strength of the conductor, sheet resistance, solder resistance,
Tests and measurements of solder wettability were conducted respectively.

First, regarding the adhesion strength of the conductor, we used a board on which a 1.5 mm square copper pattern was formed, soldered one end of a 0.6 φ tin-plated annealed copper wire parallel to the board surface, and soldered the annealed copper wire parallel to the board surface. This was done by fixing the other end of the wire to a push-pull gauge and pulling it in a direction perpendicular to the board surface until the soldered part broke. Then, the load at the time of breakage was read with a push-pull gauge and converted to the load per soldering area of 1.2. In this way, the breaking load per unit area was measured for 50 samples, and the average value is shown in Table 1 as the adhesion strength.

To measure the sheet resistance, use a Whiston bridge to measure the electrical resistance value between both ends in the longitudinal direction of a linear pattern with a width of 0.31 m and a length of 100 mm formed on the substrate, and calculate this value per unit area. This was done by converting it into a resistance value. In this way, the resistance value per unit area was measured for 50 samples, and the average value is shown in Table 1 as the sheet resistance value.

For evaluation of solder resistance, the linear pattern of the board after sheet resistance measurement was placed in a molten solder (63S n -37P b ) bath kept at 260°C and 5°C for 10 minutes.
One cycle consisted of dipping for a second, taking it out, and visually observing the flocculent pattern, and repeating this until breakage of the pattern was observed. As a result, those in which a disconnection was observed after 1 to 3 times were evaluated as unacceptable, those in which disconnection was observed in 4 to 6 times were acceptable, and those in which disconnection was observed in 7 to 9 times were evaluated as good.
Those in which no wire breakage was observed after 0 or more cycles were evaluated as excellent, and the results are shown in Table 1.

For the solder wettability evaluation test, a board on which an 81111 square copper pattern was formed was used, and after the copper pattern was immersed in 25% rosin, molten solder (63S n -37P b ) The solder was immersed in the tank for 5 seconds, taken out, and checked to see how wet the solder was. As a result, if the solder wet area is less than 80% of the copper area, it is unacceptable, if 80 to 95% is acceptable, if 96 to 99% is good, if
oo% was considered excellent and is shown in the El column of Table I.

(Examples 2 to 5) As shown in Table 1, in the above Example 1, from 4 g of 1 of manganese monoxide in the metallizing paste, 2 sr,
Examples 2 to 5 were carried out using the same method and conditions as in Example 1, except that the amounts were changed to 6 g, 8 g, and 10 g. These results are shown in columns E2 to E5 of Table 1.

(Examples 6 to 9) As shown in Table 1, in Example 1, the amount of glass powder in the metallization paste was changed from 10g to 4g, 17g,
Examples 6 to 9 were carried out using the same method and conditions as in Example 1 except that the amounts were changed to 15 g and 20 g. These results are shown in Table 1.
Shown in columns 0E6-9.

(Examples 10 to 12) As shown in Table 1, in Example 1, the type of glass powder in the metallizing paste was changed to GA-
From 12, Nippon Electric Glass GA-4, LS-0
Examples 10 to 12 were carried out using the same method and conditions as in Example 1, except for using the same GA-13. These results are shown in the EIO-12 columns of Table 1.

(Example 13) As shown in Table 1, in Example 1, 4 g of manganese monoxide in the metallizing paste was replaced with manganese tetroxide (M n
304) Example 13 was carried out using the same method and conditions as in Example 1, except that the amount was changed to 4.3 g (4 g in terms of M n O). The results are shown in the column El3 of Table 1.

(Example 14) As shown in Table 1, in Example 1, 4 g of manganese monoxide in the metallization paste was replaced with manganese trioxide (M n
20a) Example 14 was carried out using the same method and conditions as in Example 1, except that the amount was changed to 4.5 g (4 g in terms of M n O). The results are shown in column El4 of Table 1.

(Example 15) As shown in Table 1, in Example 1, 4 g of manganese monoxide in the metallizing paste was replaced with manganese dioxide (M n
02) Example 15 was carried out using exactly the same method and conditions except that 4.9 g (4 g in terms of M n O) was used. The results are shown in column E15 of Table 1.

(Example 16) As shown in Table 1, in Example 1, 4 g of manganese monoxide, charcoal Qe, manganese (M n
Example 16 was carried out using the same method and conditions as in Example 1, except that the amount of CCh) was changed to 6.6 g (4 g in terms of M n O). The results are shown in the E16 column of Table 1.

(Example 17) As shown in Table 1, in Example 1, 4 g of manganese monoxide (MnO) in the metallizing paste was replaced with 2 g of -manganese oxide (MnO) and 2 g of manganese tetroxide (MnsCL).
．． 15 g (4 g in terms of total M n O), and the glass powder was changed from GA-12 manufactured by Nippon Electric Glass Co., Ltd. to No. 4101 manufactured by Nippon Enamel R'th Yakusha, but otherwise the same as Example 1. Example 17 was carried out using the method and conditions. The results are shown in column E17 of Table 10.

(Example 18) As shown in Table 1, in Example 1, 4 g of manganese monoxide (MnO) in the metallizing paste was replaced with 2 g of -manganese oxide and 3.24 g of manganese carbonate (M n COa).
(4 g in terms of total MnO), and the glass powder was changed from GA-12 manufactured by Nippon Electric Glass Co., Ltd. to No. 4121 manufactured by Nippon Enamel Glaze Co., Ltd., but otherwise carried out using the same method and conditions as Example 1. Example 18 was carried out. This result is E18 in Table 1.
Shown in the column.

(Example 19) As shown in Table 1, in Example 1, 4 g of manganese monoxide (MnO) in the metallization paste was replaced with 45 g of manganese tetroxide ('M n 30 s ) 2' and manganese dioxide. (Mn203) 2.22g and manganese carbonate (
MnC03) 3.24g (total MnO equivalent: 6g), and the glass powder was replaced with G manufactured by Nippon Electric Glass Co., Ltd.
Example 19 was carried out using the same method and conditions as Example 1 except that A-12 was replaced with No. 4138 manufactured by Nippon Enamel Glaze Co., Ltd. The results are shown in the E19 column of Table 1.

(Example 20) As shown in Table 1, in Example 1, 4 g of manganese monoxide (MnO) in the metallization paste was replaced with 2.15 g of manganese tetroxide (M n 304) and 2 g of manganese dioxide (Mn 203). .22g and manganese dioxide (M n
02) Replaced with 2.45g (6g in total MnO conversion)
Example 20 was carried out using the same method and conditions as in Example 1 except that the glass powder was changed from GA-12 manufactured by Nippon Electric Glass Co., Ltd. to No. 631O manufactured by Nippon Enamel Glaze Co., Ltd. The results are shown in the E20 column of Table 1.

(Examples 21 to 24) As shown in Table 1, in Example 1, the amount of cuprous oxide (CuaO) in the metallizing paste was 80 g and the amount of copper metal (
Cu) ff120g, respectively 90g and 10g,
70 g and 30 i, 80 g and 40 g, 5
Examples 21 to 24 were carried out using the same method and conditions as Example 1 except that the weight was changed to 0 g and 50 g, respectively. The results are shown in columns E21-24 of Table 1.

(Comparative Examples 1 and 2) As shown in Table 2, in Example 1, the amount of manganese monoxide in the metallizing paste was changed from 4g to 1g and 12g, respectively.
Comparative Examples 1 and 2 were carried out using the same method and conditions as in Example 1, except for changing to g.

The results are shown in the CI and C2 columns of Table 2.

(Comparative Examples 3 to 4) As shown in Table 2, in Example 1, m of the glass powder in the metallizing paste was 10 g, 2 g and 25 g, respectively.
Comparative Examples 3 and 4 were carried out using the same method and conditions as in Example 1 except for the following. The results are shown in columns 03 and C4 of Table 2. (Comparative Example 5) As shown in Table 2, in the above example process, the amount of cuprous oxide (Cu20) in the metallizing paste was changed to 80 g and the amount of copper metal (Cu) was changed to 40 g and 0 g, respectively. Comparative Example 5 was carried out using the same method and conditions as in Example 1 except for the above. The results are shown in column 05 of Table 2.

As shown in the results of Examples 1 to 24 above, the manganese compound in the metallizing paste has an amount of 100 parts by weight of the copper component powder consisting of cuprous oxide and copper metal when converted to manganese oxide. When it is in the range of 2 to 1 part lomff, it contributes to improving the density of metallized copper, and is effective in improving the adhesion and solder resistance of the conductor. Moreover, sufficiently good solder wettability can be obtained. On the other hand, if the amount of the manganese compound in the metallizing paste is less than 2 parts by weight calculated as manganese monoxide with respect to 100 parts by weight of the copper component powder consisting of cuprous oxide and metallic copper, Comparative Example 1 As shown in the results, the conductor adhesion strength is 1Kg/im.
2 or less, and the solder resistance is also poor, which is not preferable. On the other hand, when exceeding the lofffffl portion, as in Comparative Example 2,
Solder wettability deteriorates, which is undesirable.

Therefore, in the present invention, M of the manganese compound in the metallized paste is limited to the above range.

When the glass powder in the metallizing paste is in the range of 4 to 20 parts by weight per 100 parts by weight of the copper component powder consisting of cuprous oxide and metallic copper, the adhesion of the metallized copper will be reduced. It is effective in improving strength, and also provides sufficiently good solder wettability and sufficiently low sheet resistance. On the other hand, M of the glass powder in the metallization paste is
If the amount is less than 4 parts by weight based on 100 parts of copper component powder consisting of cuprous oxide and metallic copper, as shown in the results of Comparative Example 3,
Adhesion strength of metallized copper is weak <, I Kg/m
m' or less, which is not preferable. On the other hand, this is 20
If it exceeds parts by weight, as shown in the results of Comparative Example 4, the solder wettability will be poor and the sheet resistance will sharply increase, which is not preferable. Therefore, in the present invention, the amount of glass powder in the metallization paste is limited to the above range.

In the metallizing paste according to the present invention, the particles for imparting conductivity to the metallized copper are copper component powder consisting of the cuprous oxide and metallic copper. Among the copper component powders, the metallic copper powder is oxidized during heat treatment in air to remove the organic binder. However, by subsequently firing in a reducing gas, the oxidized metallic copper and cuprous oxide are reduced to become metallic copper, resulting in conductivity. That is, this metallization paste can be heated in air to completely scatter the organic binder, and then fired in N2 gas containing H2 to metallize it. In this case, the amount of the reducing gas sent into the firing furnace can be reduced to about 1/3 of the conventional amount.

As for the copper component powder in the metallized paste, the more metallic copper powder there is, the lower the sheet resistance of the metalized copper is. On the other hand, if the proportion of metallic copper in the copper component powder exceeds the above range (as shown in Comparative Example 5), the adhesion strength of the metallized metal layer to the ceramic decreases rapidly.

This is because when the metallizing paste is heat-treated in air to remove the organic binder contained in the metallizing paste, the gold BfX4 in the metallizing paste is oxidized and its volume increases, causing cracks to occur in the metallizing paste. This is because a portion of it peels off from the ceramic surface. Kim Ji! ! When the copper content is 50 parts by weight or less in 100 parts by weight of the copper component powder, the above-mentioned problem does not occur. Further, when the amount of metallic copper powder in the copper component powder is less than one weight portion, the effect of containing metallic copper is poor. Therefore, in the present invention, the ratio of cuprous oxide and cupric oxide in the copper component powder is
limited to the above range.

[Effects of the Invention] As explained above, according to the present invention, as particles for imparting conductivity to be included in the metallizing paste,
By using a mixed powder of cuprous oxide and metallic copper, the unit price of the conductive material can be significantly reduced compared to the case of using gold BM powder, and the price of the metallizing paste can be reduced. Moreover, since the organic binder can be completely dispersed by heating in the air, the removal of the vV machine binder and the firing process are facilitated, improving productivity and stabilizing the properties of the metallized copper. be able to.

Claims (1)

[Claims] 100 parts by weight of a copper component mixed powder consisting of 1 to 50 parts by weight of metallic copper powder and the remainder being cuprous oxide, 2 to 10 parts by weight of manganese compound powder in terms of manganese monoxide, and 4 to 4 parts by weight of glass powder. A metallizing paste composition containing 20 parts by weight and an organic binder in an amount suitable for paste formation.