JPH0770362A - Conductive paste composition, boron-coated silver powder used in said composition and production of said powder - Google Patents

Abstract

PURPOSE:To provide a conductive paste composition capable of forming an electrode having firm adhesion to the substrate and to provide a conductive paste composition which forms an electrode, does not cause the resistance ele ment to crack on the part near to the joint between the resistance element and the primary electrode, and does net suffer from the exudation of the glass from the resistance element to the electrode during firing. CONSTITUTION:The composition is one containing a silver powder coated with 0.01-0.1wt.% (in terms of the boron atoms) at least one member selected from among diboron trioxide, alkali metal and ammonium salts of boric acid, an alkali metal salt of boron hydride and a carborane as the conductive component. A conductive paste composition comprising 73-79 pts.wt. silver powder, 0.5-2 pts.wt. palladium powder, 0.1-1.1 pts.wt. glass frit and 0.3-1.1 pts.wt. copper powder and/or copper oxide powder, the silver powder comprising 22-51 pts.wt. the coated silver powder and the balance of flaky silver powder, and the yield temperature of said glass frit being 450-600 deg.C, and fired together with a paste composition for forming a resistance element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a conductive paste composition for forming an electrode of a thick film chip resistor, silver powder used as a conductive component in the conductive paste composition, and a method for producing silver powder.

[0002]

2. Description of the Related Art In order to manufacture a thick film chip resistor used in the electronics industry, first, a conductive paste composition for forming an electrode containing silver-palladium as a conductive component is printed on an alumina substrate, A resistor paste composition containing ruthenium oxide and glass frit is printed thereon and simultaneously fired in air at about 850 ° C. to form a primary electrode and a resistor. Next, the glass paste is printed on the upper surface of the resistor, dried, and fired at about 600 ° C. in the air. Then, after adjusting the resistance value with a laser trimming device or the like, the glass paste is printed again on the resistor and dried. About 500-60 in air
Bake at 0 ° C.

After firing, the alumina substrate is cut into small chips, a side surface is coated with a silver-palladium paste by a dipping method, dried, and fired in air at about 500 to 600 ° C. to form a secondary electrode. Finally, when the chip resistor is soldered to the printed circuit board, nickel plating is applied to the exposed portion so that the primary electrode and the secondary electrode are not corroded by the solder, and the chip resistor is manufactured.

However, the above manufacturing method has the following problems. A crack occurs in the resistor near the junction between the resistor and the primary electrode due to the difference in heat shrinkage during firing, and the resistance value of the resistor varies and the current noise characteristic deteriorates. In addition, the resistor paste and the conductive paste react during firing, resulting in foaming at the contact area between the resistor and the electrode, which deteriorates stability over time, and the glass in the resistor seeps into the electrode during firing. As a result, variations in resistance value may occur or the plating property may deteriorate. In addition, there is a demand for further improvement of the adhesion strength between the substrate and the electrode in a general thick film conductive paste composition.

[0005]

DISCLOSURE OF THE INVENTION The present invention is excellent in the adhesion strength between a substrate and an electrode, does not cause cracks in the resistor near the junction between the resistor and the primary electrode, and the glass in the resistor during firing. It is an object of the present invention to provide a conductive paste composition for forming an electrode, which does not leach into an electrode, a boron-coated silver powder used as a conductive component of this conductive paste composition, and a method for producing the same.

[0006]

Means for solving the problems of the present invention include (1) diboron trioxide, alkali metal and ammonium salts of boric acid, alkali metal salts of borohydride, and carborane. One is 0.0 as boron
A conductive paste composition containing a boron-coated silver powder coated as 1 to 0.1% by weight as a conductive component.

The present invention also provides (2) as solids, 73 to 79 parts by weight of silver powder, 0.5 to 2 parts by weight of palladium powder, and 0.1 to 1.1 parts by weight of glass frit. Copper powder and / or copper oxide powder as an inorganic binder is contained in a proportion of 0.3 to 1.1 parts by weight, and among the silver powder, diboron trioxide, alkali metal and ammonium salts of boric acid, alkali metal salts of borohydride. , One of the carboranes is 0.01 as boron
~ 0.1 wt% boron-coated silver powder 22-5
The conductive paste composition comprises 1 part by weight and the remaining flaky silver powder and has a glass frit yielding temperature of 450 to 600 ° C. and is fired simultaneously with the resistor paste composition.

In the present invention, one of (3) diboron trioxide, boric acid alkali metal salt, borohydride alkali metal and ammonium salt, and carborane is 0.01 to 0.1% by weight as boron. It is in boron-coated silver powder that is coated.

The present invention provides (4) silver powder, diboron trioxide,
The method for producing a boron-coated silver powder according to (3), which comprises mixing an alkali metal salt of boric acid, an alkali metal and ammonium salt of borohydride, and one kind of aqueous solution of carborane and drying the mixture.

According to the present invention, (5) a method of producing a silver powder according to (3), in which a slurry prepared by reducing a solution containing silver ions with a reducing agent containing boron is washed by adjusting the washing degree and then dried. On the way.

[0011]

In the conductive paste composition of the present invention, the coating amount of boron of the silver powder coated with boron as 0.01 to 0.1% by weight means that the adhesion strength between the substrate and the electrode is less than 0.01% by weight. Becomes extremely small, and when the content exceeds 0.1% by weight, the resistance value of the resistor fired film rises, and the foam around the contact portion between the resistor and the electrode, the glass in the resistor only exudes into the electrode. This is because the sintered density also decreases.

In the conductive paste composition according to claim 1 of the present invention, which mainly contains silver powder as a conductive component, the average particle size of the boron-coated silver powder is not particularly limited. An average particle size of 2 μm or less, particularly an average particle size of 0.3 μm or less is preferable.
If the average particle size exceeds 2 μm, the adhesion strength with the substrate will decrease, the sintering rate will slow down, and the difference from the contraction rate with the resistor will tend to increase.

It is believed that by coating the silver powder with boron, the sinterability between the silver powders, between the silver powder and the glass frit, and the adhesion with the substrate are improved. Therefore, the boron-coated silver powder can improve the adhesion strength between the substrate and the electrode regardless of the composition of the conductive paste composition.

In the conductive paste composition containing the flake-shaped silver powder of the present invention and simultaneously fired with the resistor paste composition, the mixing ratio of the total silver powder is set to 73 to 79 parts by weight in consideration of conductivity. However, if the amount is less than 73 parts by weight, the above cracks are likely to occur, and if the amount exceeds 79 parts by weight, shrinkage during firing becomes large and the adhesion strength with the substrate decreases. Because it will be.

The proportion of boron-coated silver powder in the total silver powder is set to 22 to 51 parts by weight. When the amount is less than 22 parts by weight, the adhesion strength to the substrate is poor, and when it exceeds 51 parts by weight, the shrinkage is too large and the resistance is high. The body is easily cracked. In this conductive paste composition, it is preferable to use boron-coated silver powder having an average particle size of 0.2 μm or less, and particularly preferably an average particle size of 0.1 μm or less. When the average particle size exceeds 0.2 μm, the adhesion strength between the substrate and the electrode is lowered, the sintering rate is further slowed down, and the difference from the contraction rate with the resistor tends to be large.

Flake-like silver powder is added to improve the filling rate, but if the average particle diameter of the major axis is less than 2 μm, it becomes difficult to uniformly mix the silver powder, and the silver powder becomes difficult to handle.
On the other hand, if the average particle diameter of the major axis exceeds 5 μm, the effect of improving the filling rate is lost, and the screen is likely to be clogged, so that the average particle diameter of the major axis is 2 to 5 μm.
Use the one.

When the amount of palladium powder is 0.5 to 2 parts by weight, if it is less than 0.5 parts by weight, the silver is likely to undergo a sulfurization reaction with the sulfur gas in the air, and the electrode may be broken. If the amount of addition is too large, the price becomes too high, so the amount was limited to 2 parts by weight or less.

The glass frit does not have to be a special component, but if the yielding temperature is 450 to 600 ° C., PbO-ZnO-B ₂ other than lead borosilicate glass can be used.
_{O 3, ZnO-SiO 2 -B} 2 O 3, TiO 2 -SiO 2 -B
Various types of glass such as ₂ O ₃ and PbO-SiO ₂ -Al ₂ O ₃ can be used. If the glass yielding temperature is lower than 450 ° C, bubbles tend to be generated in the electrode, while if it exceeds 600 ° C, the adhesion strength is lowered.

The blending ratio of the glass frit is 0.1 to 1.1.
If the amount is less than 0.1 part by weight, the adhesion strength between the substrate and the electrode deteriorates, and if the amount exceeds 1.1 parts by weight, the glass is likely to seep out. The average particle size of the glass frit is preferably about 2 to 5 μm.

The mixing ratio of the copper powder and / or the copper oxide powder used as the inorganic binder is 0.3 to 1.1 parts by weight.
If it is less than 3 parts by weight, the adhesion strength between the substrate and the electrode will be inferior, and if it exceeds 1.1 parts by weight, the glass will easily exude and the plating property and solder wettability will be inferior.

A paste-forming solid content consisting of boron-coated silver powder, flake-shaped silver powder, palladium powder, glass frit, and an inorganic binder is kneaded together with a conventional vehicle in a three-roll mill or the like to form a conductive paste composition. It is a thing.

The vehicle is a resin dissolved in a solvent,
All of the commonly available ones can be used. For example, as the resin, a cellulosic resin such as ethyl cellulose and an acrylic resin such as methyl methacrylate and ethyl ethacrylate are used. As the solvent, for example, alcoholic solvents such as terpineol, decanol, etc., ketone solvents such as methyl ethyl ketone, etc. are used.

As the method for obtaining the boron-coated silver powder, a method of mixing ordinary silver powder and a solution of a substance containing boron and drying the mixture, and a method of reducing the solution containing silver ions with a reducing agent containing boron to produce the silver powder coated with boron. There is a method of drying the slurry containing the solution containing boron by adjusting the degree of cleaning when manufacturing the. The reason why the boron compound is coated as a solution in this way is that good results cannot be obtained by coating the powder.

As the silver powder for obtaining the boron-coated silver powder, usual silver powder such as precipitated silver powder and electrolytic silver powder can be used, but spherical one is particularly preferable. Boron trioxide, boric acid alkali metal salts, borohydride alkali metal and ammonium salts, dimethylamine borane, dicarbadecaborane, and other carboranes can be obtained using a solution of a substance containing boron. The silver powder may be mixed and stirred in one of the aqueous solutions, and when the amount of solvent is large, it may be filtered to form a slurry cake and dried.

The above-mentioned mixing and stirring may be carried out by an ordinary method such as a blade-type stirrer, a kneader, etc., and the above-mentioned filtration may be carried out by using a vacuum filter, a filter press or a centrifugal separator.
For drying, a vacuum dryer, a rotary dryer or the like may be used. The boron coating amount of the boron-coated silver powder may be changed by changing the concentration of boron in the solution, or may be adjusted by adjusting the content of the solution in the slurry cake to be dried.

In order to produce a boron-coated silver powder by reducing a solution containing silver ions with a reducing agent containing boron, ammonia was added to an aqueous solution of silver nitrate or the like or an aqueous solution of Ag ₂ O or AgO dissolved in nitric acid. A reducing agent containing boron such as sodium borohydride or dimethylamineborane may be used as a reducing agent in a solution containing silver ions such as a silver complex ammonia solution. Since the slurry cake obtained by separating the silver powder by filtration contains a solution containing a boron compound, a boron-coated silver powder having an arbitrary boron coating amount can be obtained by adjusting the degree of washing of the slurry cake and drying.

[0027]

【Example】

[Conductive paste composition containing only boron-coated silver powder as a conductive component] Examples 1 to 11 and Comparative Examples 1 to 8 having average particle sizes of 0.1, 0.3, 0.6, 0.8 and 1, respectively.
1.5g, 2μm spherical silver powder 40g, water 300cc,
Various amounts of reagent grade sodium metaborate (NaBO
Was charged ₂ · 4H ₂ O) to 1-liter rotary blender (Robokupu Co.), 1 15000rpm
After stirring for 1 minute, suction filtration, and drying at 80 ° C. for 20 hours, a boron-coated silver powder was obtained. The coating amount as boron is about 0.01, about 0.05, about 0.1, and about 0.15% by weight, respectively.
Met.

79 parts by weight of this silver powder are subjected to a yielding temperature of 400 ° C.
66% by weight PbO- with a thermal expansion coefficient of 8.2 × 10 ^-6 / ° C.
14 wt% ZnO-10 wt% B ₂ O ₃ based glass frit (F1) 0.6 part by weight, and an average particle size of reagent 1-5-6
0.4 parts by weight of copper oxide (CuO) powder of 15 μm
20 parts by weight of terpineol having ethyl cellulose dissolved therein was added and kneaded with a three-roll mill to prepare various conductive paste compositions.

The above paste was screen-printed on an alumina substrate having a purity of 96% by weight, dried and then placed in a continuous firing furnace for 8 hours.
Firing was performed at 50 ° C. to form 10 2 mm square pads each having a thickness of 8 μm. A tin-plated copper wire having a diameter of 0.65 mm was soldered on this pad to prepare a tensile test piece.

A peeling test was carried out by a tensile tester using two types of tensile test pieces, that is, the tensile test piece and the test piece obtained by aging the tensile test piece for 24 hours at 150 ° C. Was measured. If the adhesion strength is about 5 kgf / (4 mm ² ) or more, it can be put to practical use. In addition, the surface condition was observed with an optical microscope, and those with no rough skin were rated as x. The results are shown in Table 1.

[0031]

[Table 1] Example Boron Silver powder average adhesion strength Surface condition Content Particle size kgf / (4 mm ² ) wt% μm Initial aging After 0.01 0 0.1 6.4 6.4 6.4 2 0.01 0.3 6 0.0 6.2 3 0.01 0.01 5.1 5.3 4 0.01 0.01 1 5.2 4.9 5 0.05 0.05 6.6 6.5 6.5 6 0.05 0.8 6 .3 6.4 7 0.05 0.05 1.5 4.9 8 0.1 0.1 7 7 9 9 0.1 0.6 6.3 6.3 6.4 10 0.1 5.1 1 6.2 5. 8 11 0.1 25 5 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative example 1 0 0.1 3.9 3.6 2 0 0.6 4.7 4.7 4.3 3 0 1 5.1 5.1 4.9 4 0 2 3 2.8 5 0.15 0.1 7 7 × 6 0.15 0.6 6.5 6.4 x 7 0.15 1 6.2 5.9 x 8 0.15 2 5 4.9 x

From the results shown in Table 1, in the electrode using the silver powder not coated with boron, the surface condition was good, but the adhesion strength was low, and the silver powder having a boron coating amount of more than 0.1% by weight was used. The electrode had a high adhesion strength, but the surface was roughened.

Examples 12 to 17 In place of sodium metaborate, reagent grade diboron trioxide (B ₂ O ₃ ) and potassium borate (K ₂ B ₄ O ₇ .4H _{2) were used.}
O), ammonium borate _{((NH 4) 2 B 4} O 7 · 4H 2
O) was used, and various other boron-coated silver powders were obtained in the same manner as in Examples 1 to 11. Using this silver powder, the adhesion strength was determined in the same manner as in Examples 1 to 11, and the results of observing the surface condition are shown in Table 2. The average particle size of the silver powder used is 0.3
It was m. As a result, it can be seen that when the content of boron coated on the surface of the silver powder through the solution is within the range of the present invention, an electrode having good adhesion strength and a good surface condition can be obtained.

[0034]

Example 2 Boron coating substance Adhesion strength Surface condition Content gf / (4mm ² ) wt% Initial after aging 12 0.05 Diboron trioxide 6.1 6.2 13 0.05 0.05 Ammonium borate 6.2 6.2 14 0.05 Potassium borate 6 6.1 15 15 0.1 Diboron trioxide 6.4 6.3 16 16 0.1 Ammonium borate 6.4 5 17 0.1 Potassium borate 6.3 6 .2

Examples 18 and 19, Comparative Example 9 170 g of silver nitrate having a purity of 99.9% by weight was dissolved in 3 liters of water, and sodium borohydride (NaBH ₄ ) was added thereto.
5 g was added to reduce silver nitrate, and the solution was suction filtered to obtain a first slurry cake of silver powder. This slurry cake was added to 5 liters of water at 60 ° C., stirring and washing were performed at a rotating speed of a stirring blade of 300 rpm for 10 minutes, and suction filtration was performed to obtain a second slurry cake.

This second slurry cake and water at 60 ° C. 50
0 cc was added to the blender used in Examples 1 to 11, 4500 cc of water at 60 ° C. was further added, and the mixture was washed with stirring, and suction filtration was repeated 7 times, 12 times, 20 times, dried and coated with boron. Amount 0.1, 0.01, 0% by weight
To obtain a boron-coated silver powder. Boron coverage is measured by ICP
It was performed by optical emission spectroscopy. The average particle size of this silver powder was about 0.3 μm. Examples 1 to 1 using this silver powder
The adhesion strength was determined in the same manner as in No. 1 and the results of observing the surface condition are shown in Table 3.

Examples 20, 21 and Comparative Example 10 Reagent Primary dimethylamine borane ((CH ₃ ) ₂ NHBH
₃ ) A boron-coated silver powder was obtained in the same manner as in Examples 18 and 19 except that ₃ g was used instead of 5 g of sodium borohydride. However, the number of repeated washings was 12, 20 times, and the boron coating amounts were 0.1% by weight and 0.01% by weight. The boron coating amount was measured by ICP emission spectroscopy. The average particle size of this silver powder was about 0.3 μm. Using this silver powder, the adhesion strength was obtained in the same manner as in Examples 1 to 11, and the results of observing the surface condition are shown in Table 3.

[0038]

[Table 3] Example Boron reducing agent Adhesive strength Surface condition Content kgf / (4mm ² ) wt% After initial aging 18 0.01 Sodium borohydride 5.8 5.6 19 0.1 〃 6.6 6. 6 20 0.01 Dimethylamine borane 5.4 5.2 21 0.1 0.1 6 6.1 Comparative example 9 0 Sodium borohydride 4 3.5 10 0 Dimethylamine borane 2.9 2

[Conductive paste compositions containing silver powder and palladium powder as conductive components] Examples 22 to 27 and Comparative Examples 11 to 18 Boron-coated silver powders prepared in the same manner as in Examples 18 to 21 shown in Table 4. , Flake-shaped silver powder not coated with boron, agglomerated spherical silver powder not coated with boron, and palladium powder manufactured by the applicant with an average particle size of 0.3 μm (trade name SFP
-030) was used.

[0040]

[Table 4] Types of silver powder Morphology Average particle size Boron content μm Weight% S1 Aggregated spheres 0.1 0.014 S2 Monodispersed spheres 0.2 0.048 S3 〃 0.15 0.09 S4 Flakes 3 0 S5 〃 6 0 S6 Agglomerated sphere 0.5 0 S7 〃 0.19 0 S8 〃 3 0

Table 5 shows the glass frit used. The average particle size of the glass frit was 2 to 5 μm.

[Table 5] Type Main component composition Substitution temperature Thermal expansion coefficient Weight% ℃ × 10 ^-6 / ℃ F1 66PbO-14ZnO-10B ₂ O ₃ 400 8.2 F2 59PbO-26SiO ₂ -7B ₂ O ₃ 518 6.1 F3 〃 530 6 F4 〃 538 6.2 F5 13B ₂ O ₃ -49SiO ₂ -16TiO ₂ -12Na ₂ O-3Al ₂ O ₃ 570 9 F6 22PbO-29SiO ₂ -15Al ₂ O ₃ 710 7 7

As the inorganic binder, copper (Cu) powder having a purity of 99.5% by weight and zinc oxide (ZnO) having a purity of 99% by weight.
Powder, first-grade cuprous oxide (Cu ₂ O) powder, cupric oxide (CuO) powder, manganese dioxide (MnO ₂ ) powder, cobalt oxide (CoO) powder, and lead oxide (PbO) powder did. In both cases, the average particle size becomes 5 to 6 μm, and the particles become finer when mixed by a three-roll mill.

The raw material formulations shown in Table 6 were used in Examples 18 to 21.
A conductive paste was prepared in the same manner as in. In addition to the raw materials listed in Table 6, 1 part by weight of the above-mentioned palladium powder, 0.6 part by weight of glass frit F2, and 0.4 part by weight of CuO powder were blended. Adhesion strength was obtained using the above-mentioned paste as in Examples 1 to 11, and the results are shown in Table 6.

The above-mentioned paste was screen-printed on a 96 wt% alumina substrate, and the belt-type drying oven was operated at 120 ° C. for 1 hour.
It was dried for 5 minutes to form a 1.5 mm square pad. The resistor paste (product name 12SX) manufactured by the applicant is printed over the two test pads, and 120 is applied in a belt-type drying oven.
After drying at ℃ for 15 minutes, the electrode and the resistor were simultaneously baked at 850 ° C using a continuous baking furnace.

Before soldering a tin-plated copper wire having a diameter of 0.65 mm on the pad, electrolytic nickel plating was applied.
Electrolytic plating uses a plating bath pH of 3.5, a plating temperature of 45 ° C,
The plating current value was 0.1 A / pad and the plating time was 2 minutes. The thickness of the plating film was 5 μm. The boundary between the resistor and the electrode was observed with a scanning electron microscope to inspect the condition of glass exudation and cracks. The results are shown in Table 6 together with those in which no glass exudation or cracks were observed and those in which they were observed.

[0046]

[Table 6] Silver powder Flake silver powder Vehicle Adhesive strength Glass crack type Weight part Type Weight part Weight part kgf / 4mm ² Exudation Example After initial aging 22 S1 53 S5 23 22 8.2 7.6 23 S3 48 S5 30 20 7.1 6.9 24 S3 38 S5 36 24 7.4 6.9 25 S2 40 S4 37 21 7.7 7.3 26 S1 30 S4 48 20 8 7.8 27 S3 25 S4 50 23 7.7 6.7 Comparative Example 11 S1 80 − − 18 6.5 6.5 × 12 S2 80 − − 18 6.5 6.5 × 13 S3 70 − − 28 6.6 6.5 × 14 − − S4 79 19 4.8 4 × 15 − − S5 80 18 3.5 3.2 × 16 S6 38 S8 38 − − 22 4.9 4.7 × 17 S7 70 − − 28 3.5 3.2 × 18 S6 38 S4 38 22 5.2 2.9 × (Pd 1 part by weight, F2 0.6 part by weight, CuO 0.4 part by weight)

As shown in Table 6, in the conductive paste composition used for simultaneously firing the electrode and the resistor, cracks occurred in the electrode and the resistor when only the boron-coated silver powder was used. When only the flake-shaped silver powder, only the agglomerated silver powder not coated with boron, or the flake-shaped silver powder and the agglomerated silver powder not coated with boron were used together, not only cracks but also low adhesion strength was observed.

Examples 28 to 33, Comparative Examples 19 and 20 A conductive paste composition having the composition shown in Table 7 was prepared, and Example 2 was prepared.
Tested as in 2-27. The results are also shown in Table 7. In addition to the raw materials listed in Table 7, 3 of boron-coated silver powder S1 was used.
8 parts by weight, 38 parts by weight of flake silver powder S4, Cu
0.4 part by weight of O powder was used.

[0049]

[Table 7] Pd powder Glass frit Vehicle adhesion strength Glass crack Weight part Type Weight part Weight part kgf / 4mm ² Exudation Example After initial aging 28 0.5 F2 0.6 22.5 7.6 7 29 0.5 F3 0.6 22.5 7.6 6.9 30 0.5 F4 0.6 22.5 7.5 7.4 31 0.5 F5 0.6 22.5 7.1 6.6 32 0.5 F2 0.6 F4 0.4 23.5 7.5 7.3 33 1 F2 0.6 F5 0.4 22 7.5 6.8 Comparative example 19 0.5 F1 0.6 22.5 3.9 2.5 × 20 0.5 F6 0.6 22.5 6.1 4.7 (S1 38 parts by weight, S4 38 parts by weight, CuO 0.4 parts by weight)

In the conductive paste composition used for simultaneously firing the electrode and the resistor, glass exudation occurs when the glass frit yield temperature is less than 450 ° C., as shown in Comparative Examples 19 and 20 of Table 7. I understand. Further, it can be seen that when the temperature exceeds 600 ° C., the adhesion strength decreases.

Examples 34 to 38, Comparative Examples 21 to 23 Conductive paste compositions having the compositions shown in Table 8 were prepared and Example 2 was prepared.
Tested as in 8-33. The results are also shown in Table 8. In addition to the raw materials shown in Table 8, 3 boron-coated silver powder S1
8 parts by weight, 38 parts by weight of flake silver powder S4, Cu
0.4 part by weight of O powder was used.

[0052]

[Table 8] Pd powder Glass frit Vehicle adhesion strength Glass crack Weight part Type Weight part Weight part kgf / 4mm ² Exudation Example After initial aging 34 1 F2 0.1 22.5 6.9 6.1 35 1 F2 0.2 22.4 7 6.9 36 1 F2 0.5 22.1 7.6 7 37 1 F2 0.9 21.7 7.6 7.1 38 1 F2 1.1 21.5 7.3 7 Comparative example 21 0.5 − − 23.1 2.1 1.1 × × 22 0.5 F2 1.2 21.9 7.2 7 × 23 0.5 F2 2 21.1 7.5 7.4 × (S1 38 parts by weight, S4 38 (Parts by weight, CuO 0.4 parts by weight) From the results shown in Table 8, in the conductive paste composition used for simultaneously firing the electrode and the resistor, the yielding temperature of 450 to
It can be seen that the glass frit at 600 ° C must be 0.1-1.1 parts by weight.

Examples 39 to 42, Comparative Examples 24 to 28 A conductive paste composition having the composition shown in Table 9 was prepared and Example 3 was prepared.
It tested like 4-38. The results are also shown in Table 9. In addition to the raw materials shown in Table 9, boron-coated silver powder S1
8 parts by weight, 38 parts by weight of flake silver powder S4, and 0.5 parts by weight of glass frit F2 were used.

[0054]

[Table 9] Pd powder Inorganic binder Vehicle Adhesion strength Glass Crack Weight part Type Weight part Weight part kgf / 4mm ² Exudation Example Initial aging After 39 1 Cu ₂ O 0.4 22.1 7.3 7 40 1 Cu ₂ O 1 21.5 7.4 7.2 41 1 Cu 0.4 22.1 7.1 7 42 1 CuO 0.2 Cu 0.2 22.1 7.3 7.2 Comparative example 24 0.5 − − 23 2.5 1.1 25 1 MnO ₂ 0.5 22 3.5 2 26 0.5 ZnO 0.4 22.6 2.5 1.5 27 27 0.5 CoO 0.4 22.6 2.1 1.7 2.8 0.5 PbO 0.4 22.6 2.7 1.5 x (S1 38 parts by weight, S4 38 parts by weight, F2 0.5 parts by weight)

From the results shown in Table 9, in the conductive paste composition used for simultaneously firing the electrode and the resistor, the inorganic binder must be 0.3 to 1.1 parts by weight, and the kind thereof is Cu. It can be seen that it must be powder, Cu ₂ O powder, CuO powder.

[0056]

EFFECTS OF THE INVENTION According to the present invention, a conductive paste composition having excellent adhesion strength between a substrate and an electrode, and moreover, no crack is generated in a resistor near the junction between the resistor and the primary electrode. It is possible to provide a conductive paste composition for electrode formation in which the glass in the resistor does not exude into the electrode during firing.

Claims (6)

[Claims] 1. Boron trioxide, an alkali metal and ammonium salt of boric acid, an alkali metal salt of borohydride,
One of the carboranes is 0.01-0.1 as boron
A conductive paste composition containing, as a conductive component, boron-coated silver powder coated in a weight percentage. 2. Solid content 73 to 79 parts by weight of silver powder, 0.5 to 2 parts by weight of palladium powder, 0.1 to 1.1 parts by weight of glass frit, and copper powder as an inorganic binder. And / or copper oxide powder in an amount of 0.3 to 1.1 parts by weight, and one of diboron trioxide in silver powder, alkali metal and ammonium salt of boric acid, alkali metal salt of borohydride, and carborane. , 22 to 51 parts by weight of boron-coated silver powder coated with 0.01 to 0.1% by weight of boron, and the remaining flaky silver powder, and the glass frit has a yield temperature of 45.
A conductive paste composition that is fired at 0 to 600 ° C. at the same time as the resistor paste composition. 3. Boron trioxide, alkali metal and ammonium salts of boric acid, alkali metal salts of borohydride,
One of the carboranes is 0.01-0.1 as boron
Boron coated silver powder coated by weight%. 4. The boron according to claim 3, wherein the silver powder is mixed with diboron trioxide, an alkali metal or ammonium salt of boric acid, an alkali metal salt of borohydride, or an aqueous solution of carborane and dried. Method for producing coated silver powder. 5. The method for producing a boron-coated silver powder according to claim 3, wherein a slurry produced by reducing a solution containing silver ions with a reducing agent containing boron is washed by adjusting the washing degree and then dried. 6. The method for producing a boron-coated silver powder according to claim 5, wherein the reducing agent containing boron is sodium borohydride or dimethylamine borane.