JP3513636B2 - Composite conductive powder, conductive paste, electric circuit and method for producing electric circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention is a composite electroconductive powder BACKGROUND OF THE INVENTION The conductive paste, a process for producing electrical circuits and electrical circuits.

[0002]

2. Description of the Related Art Conventionally, as a method for forming an electric circuit (wiring conductor) such as a printed wiring board or an electronic component, an electronic material,
As described in October 1994, pages 42 to 46, a method of coating or printing a conductive paste containing silver powder having excellent conductivity is generally known.

A conductive paste containing silver powder is used for forming electric circuits and electrodes of printed wiring boards, electronic parts and the like because of its good conductivity. It is formed by using such a conductive paste. Volume resistivity of electrical circuit (specific resistance)
Is usually 50 to 100 μΩ · cm, and even excellent ones are only 30 to 40 μΩ · cm, and when the length of the printed circuit is as short as several cm, there is little trouble, but 10 cm
If it is above, the conduction resistance becomes high, and the problem is likely to occur.

In order to obtain a conductor having good conduction resistance, the amount of silver powder blended may be increased, but a specific resistance of 25 μΩ · cm or less cannot be stably obtained. Further, if the amount of silver powder is simply increased, other characteristics such as a poor balance with adhesiveness may occur.

Further, the method of etching a metal foil of silver, copper or the like has a drawback in that it is highly conductive and has a low specific resistance of several μΩ · cm, but it is expensive due to the complicated process. Also,
The conductive paste using silver powder has a drawback that when an electric field is applied in a hot and humid atmosphere, electroplating of silver called migration occurs on wiring conductors and electrodes, and electrodes or wirings are short-circuited. Several measures have been taken to prevent this migration, and measures such as applying a moisture-proof coating to the surface of the conductor or adding a corrosion inhibitor such as a nitrogen-containing compound to the conductive paste have been studied. The effect was not sufficient.

Further, in order to prevent migration, silver-palladium alloy powder may be used in place of silver powder, but such alloy powder is more expensive than silver powder and has a small size such as a hybrid IC. Although it has been put to practical use in wiring boards, it has not yet been put to practical use in substrates such as paper phenol substrates, glass epoxy substrates, and polyethylene terephthalate, which have large wiring boards. If silver-coated copper powder is used, migration can be improved, and if this is used, an inexpensive conductive paste can be obtained, but if the silver coating is uniformly and thickly coated, there is no effect of improving migration. Further, the plating method is an inexpensive method as a coating method. For example, silver plating of inexpensive spherical copper powder can be easily performed with less aggregation, but the conductive paste using this has a drawback of high resistance. It was

[0007]

[0008]

The invention according to claim 1 has a low specific resistance, a high electrical conductivity, and a small change in the specific resistance even after a thermal shock test or a humidity / humidity load test. Provide a composite conductive powder that improves the contact probability and increases the electrical conductivity of an electric circuit, and in particular, obtains a conductive paste that enhances conductivity when a circuit is printed on a sheet-shaped substrate and the printed circuit is pressed. . The invention of claim 2-7, wherein is excellent especially conductive elements of the invention according to claim 1, further claims
In addition to the invention described in 1 , there is provided a composite conductive powder capable of obtaining a conductive paste having excellent oxidation resistance and heat resistance. Claim 8 ~
The invention described in 10 provides a composite conductive powder which can be pressed to obtain a conductive paste having an anchor effect. Claim 11
The invention described above provides a composite conductive powder having a low specific resistance, a high conductivity, and a conductive paste for forming an electric circuit, which is excellent in migration resistance.

[0009] The invention of claim 12-13, wherein the specific resistance is low and highly conductive, and provides a conductive paste for a small change in the electrical circuit formed of after medium load test thermal shock test and wet resistivity . The invention according to claim 14 has a low specific resistance,
Provided is a conductive paste for forming an electric circuit, which improves the probability of contact between conductive powders, has a high electric circuit conductivity, and is excellent in migration resistance. The invention according to claim 15 is
Provided is an electric circuit having low specific resistance, high conductivity, and excellent migration resistance. The invention according to claim 16 provides an electric circuit excellent in forming a fine circuit in addition to the invention according to claim 15 . The invention according to claim 17 provides a method for manufacturing an electric circuit having a low specific resistance, high conductivity, and excellent migration resistance. Claim 1
In addition to the invention described in claim 17 , the invention described in 8 provides a method for manufacturing an electric circuit which is excellent in forming a fine circuit.

[0010]

[0011]

[0012]

[Means for Solving the Problems] ( 1 ) The aspect ratio is 6
Composite conductive powder containing conductive powder of No. 11 and conductive powder having an aspect ratio of 5 or less. ( 2 ) The composite conductive powder according to ( 1 ) above, wherein the material of the conductive powder having an aspect ratio of 6 to 11 is silver, a silver alloy, or a silver-coated conductor. ( 3 ) The composite conductive powder according to ( 1 ) above, wherein the conductive powder having an aspect ratio of 6 to 11 is a silver-coated conductive powder having an aspect ratio of 6 to 11. ( 4 ) The composite conductive powder according to ( 3 ) above, wherein the silver-coated conductor powder having an aspect ratio of 6 to 11 is silver-coated copper powder or silver-coated copper alloy powder. ( 5 ) The above ( 3 ) or ( 4 ) above, wherein the silver-coated conductor powder having an aspect ratio of 6 to 11 is a silver-coated copper powder or a silver-coated copper alloy powder from which the coated conductor is exposed. Composite conductive powder of.

( 6 ) The composite conductive powder as described in any one of ( 1 ) to ( 5 ) above, wherein the material of the conductive powder having an aspect ratio of 5 or less is silver or a silver alloy. ( 7 ) The composite conductive powder according to ( 6 ) above, wherein the conductive powder having an aspect ratio of 5 or less is reduced silver powder. ( 8 ) The composite conductive powder according to ( 6 ) above, wherein the conductive powder having an aspect ratio of 5 or less is obtained by coating a conductor having a hardness higher than that of silver or a silver alloy with silver. ( 9 ) A conductor having hardness higher than that of silver or silver alloy is Co, N
The composite conductive powder according to ( 8 ) above, which is i, Cr, Cu, W powder or an alloy powder thereof. ( 10 ) The composite conductive powder according to ( 8 ) above , wherein the conductor having a hardness higher than that of silver or silver alloy is copper powder or copper alloy powder. ( 11 ) The conductive powder having an aspect ratio of 5 or less is the silver-coated copper powder from which the coated conductor is exposed ( 8 ) to
( 10 ) The composite conductive powder according to any one of ( 10 ).

( 12 ) A conductive paste containing the composite conductive powder according to any one of (1) to ( 11 ) above, a binder and a solvent. ( 13 ) The composite conductive powder is 8 with respect to the solid content of the conductive paste.
The conductive paste according to ( 12 ) above, which is contained in an amount of 5 to 93% by weight. ( 14 ) The aspect ratio of the composite electroconductive powder according to any one of ( 1 ) to ( 11 ) above, a binder and a solvent, and an aspect ratio of 95 to 50% by weight of electroconductive powder of 6 to 11. on but which comprises 5 to 50 wt% 5 or less of the conductive powder
Serial (12) or (13), wherein the conductive paste.

( 15 ) An electric circuit formed on the surface of a base material using the conductive paste according to any one of ( 12 ) to ( 14 ). ( 16 ) The specific resistance of the electric circuit formed on the surface of the base material is 2
The electric circuit according to ( 15 ) above, which has an electric resistance of 5 μΩ · cm or less. ( 17 ) After forming a circuit pattern on the surface of the substrate with the conductive paste according to any one of ( 12 ) to ( 14 ),
A method for manufacturing an electric circuit, which comprises pressurizing and curing. ( 18 ) The specific resistance of the electric circuit formed on the surface of the base material is 2
The method for producing an electric circuit according to the above ( 17 ), which is 5 μΩ · cm or less.

[0016]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the combination of the conductive powder and the aspect ratio of the aspect ratio of 6 to 11 is 5 or less of the conductive powder, the probability of contact between the conductive particles can be improved, conductive electrical circuit In particular, when a circuit is printed on a sheet-shaped substrate and the printed circuit is pressed, the conductivity can be increased.

In the present invention, the aspect ratio of the conductive powder means the ratio of the major axis and the minor axis of the particles of the conductive powder (major axis / minor axis). In the present invention, particles of conductive powder are mixed well in a curable resin having a low viscosity, the resin is cured as it is while the particles are allowed to settle by allowing it to stand, and the resulting cured product is cut in the vertical direction. The shape of the particles appearing on the cut surface is magnified and observed with an electron microscope, the major axis / minor axis of each particle is obtained for at least 100 particles, and the average value thereof is used as the aspect ratio. Here, the minor axis, for the particles appearing on the cut surface, a combination of two parallel lines in contact with the outside of the particle is selected so as to sandwich the particle, and of the two parallel lines having the shortest spacing among those combinations. It is a distance. On the other hand, the major axis is the distance between the two parallel lines that are the longest distance among the two parallel lines that are in contact with the outside of the particle and are two parallel lines that are perpendicular to the parallel lines that determine the minor axis. is there. The rectangle formed by these four lines is the size that the particles will fit within. The specific method used in the present invention will be described later.

[0018] The conductive powder of the aspect ratio of 6 to 11, in Rushirubedenko such a substantially flat fine piece as the shape, for example, a scaly conductive powder. The aspect ratio of 5 or less <br/> conductive powder, a sphere shape, a cube shape, tetrahedral, bulk powder called substantially spherical shape, a shape with projections on the surface as Imataira sugar powder , And various kinds of irregularly shaped conductive powders such as a mixture thereof. Examples of conductive powders having various shapes include reduced silver powder .

In many cases, the conductive powder having an aspect ratio of 6 to 11 corresponds to a flat conductive powder, and in addition to this, there is a shape called dendritic shape (also called dendrite shape), which is also used together. Can be used.
As the conductive powder having an aspect ratio of 6 to 11 , an aspect ratio of 7 to 1 is obtained in that a highly conductive paste can be obtained.
1 , the aspect ratio is more preferably 8 to 11 , and the aspect ratio is more preferably 10 to 11 . Therefore, from the aspects of shape and aspect ratio, the aspect ratio is 7 to 7 in terms of high conductivity, viscosity of conductive paste, and the like.
The flat conductive powder of No. 11 is more preferable, and the aspect ratio is 8
Flat-shaped indene more preferably of to 11, the aspect ratio is most preferably 10 to 11 of the flat conductive powder.

[0020] The average particle through the particle aspect ratio is 6 to 11 of the conductive powder, from the viewpoint of not lowering the printability is preferably one 25μm or less, more preferably the following 20 [mu] m, that of 10μm or less Is more preferable. The average particle size referred to here can be measured by a laser scattering type particle size distribution measuring device. In the present invention, the measurement was performed using Mastersizer (manufactured by Malvan Co., Ltd.) as the device.

[0021] As the aspect ratio of 5 or less conductive powder,
The aspect ratio is preferably 4 or less, more preferably 3 or less, and even more preferably 2.5 or less from the viewpoint that a highly conductive paste can be obtained.

The average particle diameter of the aspect ratio of 5 or less of the conductive powder is, in terms of excellent printing properties, preferably in the range of 3 to 20 [mu] m, the range of 3~10μm is more preferable. In addition, the average particle diameter here can be measured by a laser scattering type particle size distribution measuring device, as in the above. In the present invention, the measurement was performed using Mastersizer (manufactured by Malvan Co., Ltd.) as the device.

The material of each conductive powder is preferably silver or silver alloy in terms of conductivity and oxidation resistance. As the above-mentioned silver alloy, it is preferable to use an alloy with palladium (for example, about 1 to 5% by weight in the silver alloy), platinum (for example, about 1% by weight in the silver alloy) and the like. Further, one of the methods for producing the above-mentioned silver powder is an in-liquid reduction method, and since the silver powder produced by this method is a fine powder having an average particle size of several μm, it is widely used as an industrial production method. There is. The in-liquid reduction method is a method in which silver is dissolved with an acid, then neutralized with an alkali, and then a reducing agent such as formalin and starch is added to the solution to reduce it into a fine powder. Yes, the powder obtained by this is called reduced silver powder, and its shape is
Although it is close to a lump, it has an irregular shape instead of a constant shape. This reduced silver powder can be used as an irregularly shaped conductive powder or a conductive powder having an aspect ratio of 5 or less in the present invention. Each conductive powder may be a silver-coated conductive powder in which a conductor other than silver or a silver alloy is coated with silver or a silver alloy.

As the conductive powder having an aspect ratio of 5 or less ,
Although the silver-coated conductor powder may be used as described above, the conductor to be coated is preferably a conductor having a hardness higher than that of silver or a silver alloy. As such a conductor, for example, C
Metal powders such as o, Ni, Cr, Cu, and W or alloy powders thereof can be used, and among these, copper powder or copper alloy powder is preferably used. By using this,
When the electric circuit is pressurized, the irregular-shaped conductive powder is bitten into the flat silver powder or the silver alloy powder to increase the conductivity of the electric circuit, which is preferable. As the above-mentioned copper alloy powder, for example, alloy powders of copper and tin, copper and zinc, etc. are used.

[0025] coating the silver on the surface of the aspect ratio of 5 or less of the conductive powder, displacement plating, electroplating, there are methods such as electroless plating, the aspect ratio is 5 or less of the conductive powder and silver It is preferable to coat by the displacement plating method because of high adhesiveness and low running cost .
Coverage of silver on the surface of the aspect ratio of 5 or less of the conductive powder is, the cost in the range of 3 to 50 wt% points or Raa aspect ratio, such as conductive diet of inhibitory effect against 5 or less of the conductive powder Is preferable, and the range of 3 to 20% by weight is more preferable.

It is preferable to use any of the above-mentioned silver-coated conductor powders because it has excellent migration resistance. As the silver-coated conductor powder, one in which a part of the conductor is exposed (hereinafter abbreviated as exposed-cover conductor powder) can be used. Exposed coated conductor powder can aspect ratio conductive powder and A spectrum <br/> Ratio of 6 to 11 is used for each 5 or less of the conductive powder. The exposed area of the conductive powder is 50 in terms of obtaining good conductivity.
% Or less is preferable, and 20% or less is more preferable.

Since the spherical silver-coated copper powder or silver-coated copper alloy powder after displacement plating has few contact points, the resistance tends to increase. Therefore, the spherical silver-coated copper powder or silver-coated copper alloy powder after displacement plating may be impacted to change the shape of the particles to have an aspect ratio of 6 to 11. Specifically, it can be deformed by a method such as a ball mill or a vibration mill.

The mixing ratio of the conductive powder and the aspect ratio of the aspect ratio of 6 to 11 is 5 or less of the conductive powder is, Shi pair conductive powder of the aspect ratio is 6 to 11 within 95 to 50% by weight A spectrum < br /> preferred from the viewpoint of enhancing the conductivity may ratio is 5 or less of the conductive powder is in the range of 5 to 50 wt%, aspect ratio is 6
11 conductive powder of Shi pairs 80 to 60 wt% aspect ratio of 5 or less of the conductive powder is more preferably ranges from 20 to 40 wt%.

The conductive paste contains these composite conductive powders, a binder and a solvent. In this conductive paste, the content of the composite conductive powder is 85 to 85 in terms of the resistance, economy and adhesiveness of the conductor with respect to the solid content of the conductive paste.
It is preferably 93% by weight, more preferably 87 to 90% by weight.

A liquid epoxy resin, a phenol resin, an unsaturated polyester resin or other organic adhesive component is used as the binder, and terpineol, ethyl carbitol, carbitol acetate, butyl cellosolve or the like is used as the solvent. To be In addition to the above materials, the conductive paste is added with a hardening agent for organic adhesive components such as 2-ethylmethylimidazole and, if necessary, a corrosion inhibitor such as benzothiazole and benzimidazole, and fine graphite powder, and uniformly mixed. Obtained. The content of the binder and the solvent is 7 to 15 wt% of the binder and 10 of the solvent with respect to the conductive paste in terms of conductivity, adhesiveness and printability.
Is preferably in the range of ~ 35 wt% and the binder is 7
It is more preferable that the range is -12 wt% and the solvent is 15-25 wt%. In addition, the content of the curing agent is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the binder in terms of workability. The corrosion inhibitor and the fine graphite powder are added as needed, but if added, the content of the corrosion inhibitor is 0.
It is preferably in the range of 1 to 3 parts by weight. The fine graphite powder is preferably in the range of 1 to 10% by weight with respect to the conductive paste.

The method for forming the electric circuit is not particularly limited, and a known method, for example, a conductive paste can be formed by screen printing or a drawing machine controlled by a computer. As the substrate, a polyethylene terephthalate film, a polyimide film, a polyamideimide film, a paper phenol laminate, an epoxy resin glass cloth substrate laminate, a polyimide resin glass cloth substrate laminate, or the like is used.

In the present invention, the specific resistance of the electric circuit is preferably 25 μΩ · cm or less, more preferably 15 μΩ · cm.
cm or less, and if it exceeds 25 μΩ · cm, conductivity tends to decrease, resulting in a large voltage drop in the electric circuit.
It becomes difficult to make a fine electric circuit. It is particularly preferable that the electric circuit has a specific resistance of 10 μΩ · cm or less, because it can be used in an electric circuit having a long line length such as a fine planar antenna having a coil shape. The specific resistance of the electric circuit of 25 μΩ · cm or less can be achieved by forming a circuit pattern on the surface of the base material with the above-mentioned conductive paste, and then pressing it with a press to densify the circuit pattern. As a pressing method, a method of applying pressure using a surface plate, a method of pressing with a roll, or the like is applied as long as the efficiency of contact between powders in a conductive layer formed of a conductive paste can be increased. Note that the binder in the conductive layer is preferably softened during pressing, and if the binder is in a semi-cured state or hardened, it is preferably heated and softened before use. The binder may be cured after pressing or during pressing.

[0033]

EXAMPLES Examples of the present invention will be described below. Example 1 Bisphenol A type epoxy resin (oiled shell epoxy
Co., Ltd., trade name Epikote 834 60 parts by weight and bisphenol A type epoxy resin (Yukaka Shell Epoxy Co., Ltd.)
Manufactured by Eikopto 828) (40 parts by weight) was dissolved by heating in advance and then cooled to room temperature, and then 5 parts by weight of 2 ethyl 4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd.), 20 parts by weight of ethyl carbitol and butyl cellosolve. 20 parts by weight were added and mixed uniformly to obtain a resin composition.

Next, a flaky silver powder having an aspect ratio of 8 and an average long diameter of 8 μm (trade name: T, manufactured by Tokuriki Kagaku Kenkyusho)
CG-1) 210 parts by weight (79.2% by weight) and a silver powder having an aspect ratio of 2.3 and a major axis having an average particle diameter of 7 μm (manufactured by Rare Metallic Co., Ltd.) (hereinafter, referred to as silver powder having an aspect ratio of 2.3). 55 parts by weight (20.8% by weight) was added, and then this was added to 145 parts by weight of the resin composition obtained above, and the mixture was uniformly mixed and dispersed with a stirrer and a triple roll to obtain a conductive paste. Obtained. The content of the composite silver powder of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 80% by weight based on the solid content of the conductive paste.

Then, using the conductive paste obtained above, a silver conductor circuit 1 shown in FIG. 1 was printed on a polyethylene terephthalate film having a thickness of 125 μm in the air at 60 ° C. for 30 minutes and further at 145 ° C. A heat treatment was performed under the condition of 30 minutes to obtain a wiring board. In FIG. 1, 2 is a polyethylene terephthalate film. Then, the specific resistance of the obtained wiring board was measured and found to be 52 μΩ · cm.
As a result of the thermal shock test of the wiring board, the rate of change in specific resistance was 5%. Further, as a result of performing a wet and medium load test on the wiring board, the rate of change in specific resistance was 8%. The cooling and heating test conditions were 100 cycles of 125 ° C. for 30 minutes to −65 ° C. for 30 minutes, and the humidity and medium load test was 100 at 40 ° C. and 90% RH.
Hold for 0 hours.

The specific measuring method of the aspect ratio in this embodiment is shown below. 8g of base material (No.20-8130) of low-viscosity epoxy resin (manufactured by Buehler) and curing agent (No.2)
0-8132) 2 g were mixed, and 2 g of the conductive powder was mixed and well dispersed therein, and then vacuum degassing was performed at 30 ° C., and then 6 to 8
The particles were allowed to settle and harden by standing at 30 ° C. for a time. Then, the obtained cured product was cut in the vertical direction, the cut surface was magnified 2000 times with an electron microscope, and the 100 appeared on the cut surface.
The major axis / minor axis of each particle was obtained, and the average value thereof was used as the aspect ratio.

Example 2 Example 1 except that 400 parts by weight (80% by weight) of the flaky silver powder used in Example 1 and 100 parts by weight (20% by weight) of silver powder having an aspect ratio of 2.3 were blended. A conductive paste was obtained through the same steps as. The content of the composite silver powder of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 85% by weight based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 1 and the characteristics thereof were evaluated. As a result, the specific resistance of the wiring board was 43 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in specific resistance was 4%.
The rate of change in specific resistance was 7%.

Example 3 320 parts by weight (80% by weight) of the flaky silver powder used in Example 1 and 80 parts by weight of silver powder having an aspect ratio of 2.3 (2
A conductive paste was obtained through the same steps as in Example 1 except that 0% by weight) was blended. The content of the composite silver powder of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 86% by weight based on the solid content of the conductive paste. Example 1 below
A wiring board was manufactured through the same steps as above, and its characteristics were evaluated. As a result, the specific resistance of the wiring board was 39 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 6%.

Example 4 The wiring board obtained in Example 3 was heated and pressed with a hot press at a temperature of 100 ° C. and a pressure of 10 MPa to densify the silver conductor circuit and evaluate its characteristics. As a result, the specific resistance of the densified wiring board was 22 μΩ · cm. Further, as a result of a thermal shock test of the densified wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 4%.

The addition of silver powder 400 parts by weight of scaly used in Comparative Example 1 obtained in Example 1 resin composition 145 parts by weight in Example 1, were uniformly mixed and dispersed in the same manner as in Example 1 To obtain a conductive paste.
A wiring board was manufactured through the same steps as in Example 1 below, and the characteristics thereof were evaluated. As a result, the specific resistance of the wiring board is 62 μΩ.
・ It was cm. As a result of the thermal shock test of the wiring board, the rate of change of the specific resistance was 10%, and the result of the wet and medium load test showed the rate of change of the specific resistance to be 9%.

Comparative Example 2 A wiring board was obtained through the same steps as in Example 1 except that the conductive paste obtained in Comparative Example 1 was used. Next, the wiring board was heated and pressed under the same conditions as in Example 4 using a hot press to densify the silver conductor circuit, and its characteristics were evaluated. As a result, the specific resistance of the densified wiring board was 58 μΩ · cm. As a result of a thermal shock test conducted on the densified wiring board, the rate of change in resistivity was 10%, and the result of the wet / medium load test showed a rate of change in resistivity of 9%.

Example 5 Ni powder having an aspect ratio of 2 and an average long diameter of 3 μm (manufactured by Kojundo Chemical Co., Ltd.) was degreased with an acidic cleaner (manufactured by Nippon MacDermid, trade name L-5B), washed with water, and 20 g of AgCN was added.
/ H ₂ O 1 liter and NaCN 40 g / H ₂ O 1 liter, electroless plating was performed so that the amount of silver was 15% by weight based on the above Ni powder, and the silver-coated Ni was washed with water and dried. Got the powder.

Next, a flaky silver powder having an aspect ratio of 8 and an average long diameter of 8 μm (trade name: T, manufactured by Tokuriki Kagaku Kenkyusho)
CG-1) 210 parts by weight (91.3% by weight) and 20 parts by weight (8.7% by weight) of the silver-coated Ni powder obtained above were blended, and this was then added to the resin composition obtained in Example 1. 145
It was added to parts by weight and uniformly mixed and dispersed with a stirrer and a triple roll to obtain a conductive paste. The content of the composite conductive powder of the flaky silver powder and the silver-coated Ni powder was 61.3% by weight based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 1 and the characteristics thereof were evaluated. As a result, the specific resistance of the wiring board was 43 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in specific resistance was 5%, and the result of the wet and medium load test showed a rate of change in specific resistance of 8%.

Example 6 400 parts by weight of the flaky silver powder used in Example 5 (88.
9% by weight) and 50 parts by weight (11.1% by weight) of the silver-coated Ni powder obtained in Example 5 were mixed, and a conductive paste was obtained through the same steps as in Example 5. The content of the composite conductive powder of the flaky silver powder and the silver-coated Ni powder was 73.4% by weight based on the solid content of the conductive paste. Example 5 below
A wiring board was manufactured through the same steps as above, and its characteristics were evaluated. As a result, the specific resistance of the wiring board was 43 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in resistivity was 4%, and the result of the wet / medium load test showed a rate of change in resistivity of 7%.

Example 7 320 parts by weight of the flaky silver powder used in Example 5 (91.
4% by weight) and 30 parts by weight (8.6% by weight) of the silver-coated Ni powder obtained in Example 5 were blended to obtain a conductive paste through the same steps as in Example 5. The content of the composite conductive powder of the flaky silver powder and the silver-coated Ni powder was 70.7% by weight based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 5 and the characteristics thereof were evaluated. As a result, the specific resistance of the wiring board was 38 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 6%.

Example 8 320 parts by weight of the flaky silver powder used in Example 5 (80.
0% by weight) and 80 parts by weight (20.0% by weight) of the silver-coated Ni powder obtained in Example 5 were blended to obtain a conductive paste through the same steps as in Example 5. The content of the composite electroconductive powder of the flaky silver powder and the silver-coated Ni powder was 89.9% by weight based on the solid content of the electroconductive paste. Example 5 below
A wiring board was produced through the same steps as in. Then, the printed circuit was densified by heating and pressing the wiring board with a hot press under the conditions of a temperature of 100 ° C. and a pressure of 10 MPa, and its characteristics were evaluated. As a result, the specific resistance of the densified wiring board is 20 μΩ ・
It was cm. Further, as a result of a thermal shock test of the densified wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 4%.

Example 9 A flaky silver powder A (manufactured by Tokuriki Kagaku Kenkyusho, trade name TCG-1) having an aspect ratio of 8 and an average long diameter of 8 μm was used in an attritor (manufactured by Mitsui Mining Co., Ltd.). Crushed, flaky silver powder B4 with aspect ratio of 11 and average particle size of 20 μm
00 parts by weight (66.7% by weight) and an aspect ratio of 2.
Silver powder with an average particle size of 3 and 7 μm (made by Rare Metallic Co., Ltd.)
200 parts by weight (hereinafter referred to as silver powder having an aspect ratio of 2.3) (33.3% by weight) was blended, and this was added to 145 parts by weight of the resin composition obtained in Example 1 and stirred. The mixture was uniformly mixed and dispersed by a machine and a triple roll to obtain a conductive paste. The ratio of the scaly silver powder B to the silver powder having an aspect ratio of 2.3 was 6.67: 3.33 in a volume ratio (scaly silver powder B: silver powder having an aspect ratio of 2.3). The composite conductive (silver) powder was contained in an amount of 85.1% by weight based on the solid content of the conductive paste.

Next, the conductive paste obtained above was printed on the test pattern shown in FIG.
A circuit board 6 having a 5 μm circuit 4 formed thereon was obtained. Board 3
Is a polyethylene terephthalate film (thickness: 125
μm) and heat curing conditions are 60 ° C. for 30 minutes + 145 ° C.
It took 45 minutes. The specific resistance of the obtained circuit board 6 is 42 μΩ.
・ It was cm. As a result of the thermal shock test of the circuit board 6, the rate of change in specific resistance was 5%. Further, as a result of performing a humidity and medium load test on the circuit board 6, the rate of change in specific resistance was 8%. The cold heat test conditions are 125 ° C. for 30 minutes
100 cycles of −65 ° C. for 30 minutes were performed, and the humidity and humidity load test was held at 40 ° C. and 90% RH for 1000 hours. On the other hand, on the upper surface of the chip mounting portion 5 of the circuit board 6, the IC chip 8 in which the test circuit 7 is formed on the silicon substrate 9 shown in FIG.
As shown in Fig. 2, an anisotropic conductive sheet (manufactured by Hitachi Chemical Co., Ltd., trade name Anisolm 82) is placed so that the test circuit 7 is on the lower side.
01) (not shown) and placed and connected. The average value of the connection resistance including the anisotropic conductive sheet was 45 mΩ, and the maximum value was 63 mΩ.

Example 10 350 parts by weight of the flaky silver powder B used in Example 9 (50
%) And 350 parts by weight (50% by weight) of silver powder having an aspect ratio of 2.3 were added to 145 parts by weight of the resin composition obtained in Example 1 and then uniformly mixed in the same manner as in Example 9. A conductive paste was obtained by mixing and dispersing. The ratio of the flaky silver powder B to the silver powder having an aspect ratio of 2.3 was 5: 5 by volume ratio (scaly silver powder B: silver powder having an aspect ratio of 2.3). The composite conductive (silver) powder was contained in an amount of 43.2% by volume (86.9% by weight) based on the solid content of the conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated. As a result, the specific resistance is 41μ.
It was Ω · cm. As a result of the thermal shock test of the circuit board, the rate of change of the specific resistance was 4%, and the result of the wet and medium load test showed the rate of change of the specific resistance to be 7%. Further, as in Example 9, the average value of the connection resistance when the test circuit was connected using the anisotropic conductive sheet was 40 mΩ, and the maximum value was 55 mΩ.

Example 11 650 parts by weight of scaly silver powder B used in Example 9 (7
2.2 wt%) and silver powder 250 having an aspect ratio of 2.3
145 parts by weight of the resin composition obtained in Example 1 was added with a mixture of 2 parts by weight (27.8% by weight), and uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. The ratio between the flaky silver powder B and the silver powder having an aspect ratio of 2.3 was 7.22: 2.78 (scaly silver powder B: silver powder having an aspect ratio of 2.3) by volume. The composite conductive (silver) powder was contained in an amount of 49.5% by volume (89.6% by weight) based on the solid content of the conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated.
As a result, the specific resistance was 39 μΩ · cm. As a result of the thermal shock test of the circuit board, the rate of change in resistivity was 5
%, And the rate of change in specific resistance was 6% as a result of the wet and medium load test. Furthermore, as in Example 9, the average value of the connection resistance when the test circuit was connected using the anisotropic conductive sheet was 38 mΩ, and the maximum value was 58 mΩ.

Example 12 700 parts by weight of the flaky silver powder B used in Example 9 (5
8.3% by weight) and an aspect ratio of 2.3 silver powder 500
145 parts by weight of the resin composition used in Example 1 was added to a mixture of 4 parts by weight (41.7% by weight), and uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. The ratio of the flake-shaped silver powder B to the silver powder having an aspect ratio of 2.3 is 5.83: 4.17 (flake-shaped silver powder B:
The silver powder had an aspect ratio of 2.3. The composite conductive (silver) powder was contained in an amount of 56.6% by volume (91.9% by weight) based on the solid content of the conductive paste. A circuit board was prepared through the same steps as in Example 9 except that the heating and curing conditions were 60 ° C. for 30 minutes and 110 ° C. for 1 hour, and then the circuit board was heated and pressed under the conditions of 100 ° C. and 9.8 MPa with a hot press. The circuit was densified to evaluate its characteristics. As a result, the specific resistance was 9.
It was 1 μΩ · cm. As a result of the thermal shock test of the circuit board, the rate of change of the specific resistance was 5%, and the result of the wet and medium load test was that the rate of change of the specific resistance was 4%. Furthermore, as in Example 9, the average value of the connection resistance when connecting using the anisotropic conductive sheet was 32 mΩ, and the maximum value was 42 m.
It was Ω.

Comparative Example 3 600 parts by weight of the flaky silver powder B used in Example 9 was added to 145 parts by weight of the resin composition obtained in Example 1, and the mixture was uniformly mixed in the same manner as in Example 9 below. Dispersed to obtain a conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated. As a result, the specific resistance is 46 μΩ.
・ It was cm. As a result of the thermal shock test of the circuit board, the rate of change in resistivity was 10%, and the result of the wet and medium load test showed a rate of change in resistivity of 9%. Furthermore, as in Example 9, the average value of the connection resistance when connecting using the anisotropic conductive sheet was 1.05Ω, and the maximum value was 12 mΩ.
Met.

Example 13 380 parts by weight of the flaky silver powder B used in Example 9 (6
Silver powder 220 having an aspect ratio of 2.3)
A mixture containing 1 part by weight (36.7% by weight) was added to 145 parts by weight of the resin composition obtained in Example 1, and the mixture was uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. . The volume ratio of the flaky silver powder B to the silver powder having an aspect ratio of 6.33: 3.67 (scaly silver powder B:
The silver powder had an aspect ratio of 2.3. The composite conductive (silver) powder was contained in an amount of 39.5% by volume (85.1% by weight) based on the solid content of the conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated.
As a result, the specific resistance was 43 μΩ · cm. As a result of the thermal shock test of the circuit board, the rate of change in resistivity was 5
%, And the rate of change in specific resistance was 8% as a result of the wet and medium load test. Further, as in Example 9, the average value of the connection resistance when the test circuit was connected using the anisotropic conductive sheet was 42 mΩ, and the maximum value was 60 mΩ.

Example 14 380 parts by weight of the flaky silver powder B used in Example 9 (5
4.2% by weight) and an aspect ratio of 2.3 silver powder 320
145 parts by weight of the resin composition obtained in Example 1 was added with a mixture of 4 parts by weight (45.8% by weight), and uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. The ratio of the flaky silver powder B to the silver powder having an aspect ratio of 2.3 was 5.42: 4.58 by volume (scaly silver powder B: silver powder having an aspect ratio of 2.3). The composite conductive (silver) powder was contained in an amount of 43.2% by volume (86.9% by weight) based on the solid content of the conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated.
As a result, the specific resistance was 43 μΩ · cm. As a result of the thermal shock test of the circuit board, the rate of change in resistivity was 4
%, And the rate of change in specific resistance was 7% as a result of the wet and medium load test. Further, as in Example 9, the average value of the connection resistance when the test circuit was connected using the anisotropic conductive sheet was 38 mΩ, and the maximum value was 52 mΩ.

Example 15 600 parts by weight of the flaky silver powder B used in Example 9 (6
6.7 wt%) and an aspect ratio of 2.3 silver powder 300
145 parts by weight of the resin composition obtained in Example 1 was added with the mixture of 3 parts by weight (33.3% by weight), and uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. The ratio of the scaly silver powder B to the silver powder having an aspect ratio of 2.3 was 6.67: 3.33 in a volume ratio (scaly silver powder B: silver powder having an aspect ratio of 2.3). The composite conductive (silver) powder was contained in an amount of 49.5% by volume (89.6% by weight) based on the solid content of the conductive paste. A circuit board was manufactured through the same steps as in Example 9 below, and the characteristics thereof were evaluated.
As a result, the specific resistance was 35 μΩ · cm. As a result of the thermal shock test of the circuit board, the rate of change in resistivity was 5
%, And the rate of change in specific resistance was 6% as a result of the wet and medium load test. Furthermore, as in Example 9, the average value of the connection resistance when the test circuit was connected using the anisotropic conductive sheet was 36 mΩ, and the maximum value was 56 mΩ.

Example 16 650 parts by weight of the flaky silver powder B used in Example 9 (5
4.2% by weight) and an aspect ratio of 2.3 silver powder 550
145 parts by weight of the resin composition used in Example 1 was added to the resin composition used in Example 1, and uniformly mixed and dispersed in the same manner as in Example 9 to obtain a conductive paste. The volume ratio of the flaky silver powder B to the silver powder having an aspect ratio of 2.32: 4.58 (scaly silver powder B:
The silver powder had an aspect ratio of 2.3. The composite conductive (silver) powder was contained in an amount of 56.6% by volume (91.9% by weight) based on the solid content of the conductive paste. Thereafter, a circuit board is manufactured through the same steps as in Example 9, and then 1 by a hot press.
The circuit was densified by heating and pressurizing under the conditions of 00 ° C. and 9.8 MPa, and its characteristics were evaluated. As a result, the specific resistance is 8.7 μΩ.
・ It was cm. As a result of the thermal shock test of the circuit board, the rate of change of the specific resistance was 5%, and the result of the wet and medium load test was that the rate of change of the specific resistance was 4%. Furthermore, as in Example 9, the average value of the connection resistance when connecting using the anisotropic conductive sheet was 30 mΩ, and the maximum value was 40 mΩ.

Example 17 A flaky silver powder having an aspect ratio of 8 and an average long diameter of 8 μm (manufactured by Tokuriki Kagaku Kenkyusho, trade name TCG-1) 450
150 parts by weight (75% by weight) and 150 parts by weight (25% by weight) of silver powder (produced by Rare Metallic Co., Ltd.) having an aspect ratio of 2.3 and an average major axis diameter of 7 μm (hereinafter, referred to as silver powder having an aspect ratio of 2.3). ) Was blended and then added to 145 parts by weight of the resin composition obtained in Example 1 and uniformly mixed and dispersed with a stirrer and a triple roll to obtain a conductive paste. The content of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 39.5% by volume (85.1% by weight) based on the solid content of the conductive paste.

After manufacturing a wiring board through the same steps as in Example 1, the wiring board was heated and pressed by a hot press at a temperature of 110 ° C. and a pressure of 10 MPa for 2 minutes, and then 145
It was cured at 30 ° C. for 30 minutes to form an electric circuit having a dense circuit pattern. The specific resistance of this electric circuit was measured and found to be 13 μΩ · cm. As a result of the thermal shock test of the wiring board, the rate of change in specific resistance was 5%. Moreover, as a result of performing a humidity and medium load test on the wiring board, the rate of change in specific resistance was 7%. The cooling test conditions are 125 ° C for 30 minutes-
100 cycles of 65 ° C. for 30 minutes, 4 in humidity and medium load test
It was kept at 0 ° C. and 90% RH for 1000 hours.

Example 18 550 parts by weight of the flaky silver powder used in Example 17 (8
4.6% by weight) and an aspect ratio of 2.3 silver powder 100
Example 17 except that parts by weight (15.4% by weight) were blended.
A conductive paste was obtained through the same steps as. The content of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 41.4% by volume (86.1% by weight) based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 17, and an electric circuit was further formed to evaluate the characteristics. As a result, the specific resistance of the electric circuit was 10 μΩ · cm. As a result of conducting a thermal shock test of the wiring board,
The rate of change in resistivity was 4%, and the result of the wet and medium load test showed that the rate of change in resistivity was 7%.

Example 19 900 parts by weight of the flaky silver powder used in Example 17 (8
Silver powder 200 having an aspect ratio of 2.3)
Example 17 except that parts by weight (18.2% by weight) were blended.
A conductive paste was obtained through the same steps as. The content of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 55% by volume (91.5% by weight) based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 17, and an electric circuit was further formed to evaluate the characteristics. As a result, the specific resistance of the electric circuit was 8.2 μΩ · cm. As a result of conducting a thermal shock test of the wiring board,
The rate of change in resistivity was 5%, and the result of the wet and medium load test showed that the rate of change in resistivity was 6%.

Example 20 The wiring board obtained in Example 19 was heated and pressed with a hot roll at a speed of 30 cm / min at a temperature of 125 ° C. and a pressure of 980 N / cm, and then cured at 145 ° C. for 30 minutes. Then, an electric circuit having a dense circuit pattern was formed. The specific resistance of this electric circuit was measured and found to be 8.3 μΩ · cm. As a result of the thermal shock test of the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 4%.

Example 21 410 parts by weight of the flaky silver powder used in Example 17 (6
6.7 wt%) and silver powder 205 having an aspect ratio of 2.3
Example 17 except that parts by weight (33.3% by weight) were blended.
A conductive paste was obtained through the same steps as. The content of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 40% by volume (85.4% by weight) based on the solid content of the conductive paste. A wiring board was obtained through the same steps as in Example 17 below. Next, the wiring board obtained above was heated and pressed for 2 minutes at a temperature of 100 ° C. and a pressure of 5 MPa with a hot press, and then cured at 145 ° C. for 30 minutes to form an electric circuit with a dense circuit pattern. When the specific resistance of this electric circuit was measured, it was 12 μΩ · cm. As a result of the thermal shock test of the wiring board, the rate of change in specific resistance was 5%. Further, as a result of performing a wet and medium load test on the wiring board, the rate of change in specific resistance was 8%. The cooling test condition is 125
100 cycles of 30 ° C. to −65 ° C. for 30 minutes were performed, and the humidity and medium load test was held at 40 ° C. and 90% RH for 1000 hours.

Example 22 600 parts by weight of the flaky silver powder used in Example 17 (80
Wt%) and 150 parts by weight (20% by weight) of silver powder having an aspect ratio of 2.3 were added, and a conductive paste was obtained through the same steps as in Example 17. The content of the flaky silver powder and the silver powder having an aspect ratio of 2.3 was 45% by volume (87.7% by weight) based on the solid content of the conductive paste. Hereinafter, a wiring board was manufactured through the same steps as in Example 17, then an electric circuit was formed through the same steps as in Example 21, and the characteristics thereof were evaluated. As a result, the specific resistance of the electric circuit was 10 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in resistivity was 4%, and the result of the wet / medium load test showed a rate of change in resistivity of 7%.

Example 23 800 parts by weight of the flaky silver powder used in Example 17 (7
2.7% by weight) and an aspect ratio of 2.3 silver powder 300
Example 17 except that parts by weight (27.3% by weight) were blended.
A conductive paste was obtained through the same steps as. The content of the composite silver powder of the flaky silver powder and the silver powder with an aspect ratio of 2.3 is 54.5% by volume based on the solid content of the conductive paste.
(91.3% by weight). A wiring board was manufactured through the same steps as in Example 17, and an electric circuit was further formed to evaluate the characteristics. As a result, the specific resistance of the electric circuit was 8.5 μΩ · cm. As a result of a thermal shock test of the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 6%.

Example 24 The wiring board obtained in Example 23 was heated and pressed with a hot roll at a speed of 30 cm / min at a temperature of 125 ° C. and a pressure of 980 N / cm, and then cured at 145 ° C. for 30 minutes. An electric circuit having a dense circuit pattern was formed. When the specific resistance of this electric circuit was measured, it was 8.4 μΩ · cm. As a result of the thermal shock test of the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 4%.

[0066]

[0067]

[0068]

Example 27 900 parts by weight of the flaky silver powder used in Example 17 (8
(7.4% by weight) and 130 parts by weight (12.6% by weight) of Ni powder having a surface plated with 10% by weight of silver were blended to obtain a conductive paste through the same steps as in Example 17.
The content of the flaky silver powder and the Ni powder was 53.5% by volume (91% by weight) based on the solid content of the conductive paste. A wiring board was manufactured through the same steps as in Example 17, and an electric circuit was formed through the same steps as in Example 25, and the characteristics thereof were evaluated. As a result, the specific resistance of the electric circuit was 8.2 μΩ · cm. As a result of performing a thermal shock test on the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 5%.

Example 28 The wiring board obtained in Example 27 was heated and pressed with a hot roll at a rate of 30 cm / min at a temperature of 125 ° C. and a pressure of 980 N / cm, and then cured at 145 ° C. for 30 minutes. Then, an electric circuit having a dense circuit pattern was formed. The specific resistance of this electric circuit was measured and found to be 8.5 μΩ · cm. As a result of performing a thermal shock test on the wiring board, the rate of change in resistivity was 5%, and the result of the wet / medium load test showed a rate of change in resistivity of 5%.

[0071]

[0072]

Example 31 750 parts by weight of the flaky silver powder used in Example 17 (8
3.3 wt%) and 150 wt parts (16.7 wt%) of Ni powder having a surface plated with 10 wt% silver were blended to obtain a conductive paste through the same steps as in Example 17.
The content of the composite conductive powder of the flaky silver powder and the silver powdered Ni powder was 50.50 with respect to the solid content of the conductive paste.
It was 0% by volume (89.7% by weight). Example 17 below
A wiring board was prepared through the steps similar to those of Example 29.
An electric circuit was formed through the same steps as above, and its characteristics were evaluated. As a result, the specific resistance of the electric circuit was 8.3 μΩ · cm. As a result of conducting a thermal shock test of the wiring board,
The rate of change in resistivity was 5%, and the result of the wet and medium load test showed that the rate of change in resistivity was 4%.

Example 32 The wiring board obtained in Example 31 was heated and pressed with a hot roll at a speed of 30 cm / min at a temperature of 125 ° C. and a pressure of 980 N / cm, and then cured at 145 ° C. for 30 minutes. An electric circuit having a dense circuit pattern was formed. When the specific resistance of this electric circuit was measured, it was 8.4 μΩ · cm. As a result of the thermal shock test of the wiring board, the rate of change of the specific resistance was 4%, and the result of the wet and medium load test showed the rate of change of the specific resistance to be 4%.

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

Composite conductor indene according to claim 1, wherein according to the present invention, the specific resistance is low and highly conductive, and after intermediate load test thermal shock test and humidity even small changes in resistivity, also the probability of contact between the conductive powder It is possible to obtain a conductive paste which improves the conductivity of an electric circuit and improves the conductivity particularly when the circuit is printed on a sheet-shaped substrate and the printed circuit is pressed. Claims 2 to 7
Composite conductor indene description is particularly excellent in electrical conductivity of the composite conductive powder according to claim 1, wherein the conductive paste is excellent in oxidation resistance and heat resistance can be obtained in addition to the composite electroconductive powder according to claim 8. The composite conductive powder according to claims 8 to 10 is pressed to obtain a conductive paste having an anchor effect. Claim 1
The composite conductive powder described in 1 provides a conductive paste for forming an electric circuit, which has a low specific resistance, high conductivity, and excellent migration resistance.

The conductive paste according to claims 12 to 13 is
It is suitable for forming an electric circuit having a low specific resistance, high conductivity, and a small change in specific resistance even after a thermal shock test or a humidity / humidity load test. The conductive paste according to claim 14 is suitable for forming an electric circuit, which has a low specific resistance, improves the probability of contact between conductive powder particles, has a high electric circuit conductivity, and is excellent in migration resistance. The electric circuit according to claim 15 has a low specific resistance, high conductivity, and excellent migration resistance. The electric circuit according to claim 16 is excellent in forming a fine circuit in addition to the electric circuit according to claim 15 . According to the method of manufacturing an electric circuit of claim 17, an electric circuit having a low specific resistance, high conductivity and excellent migration resistance can be manufactured. A method of manufacturing an electric circuit according to claim 18 ,
In addition to the method for manufacturing an electric circuit according to claim 17, an electric circuit excellent in forming a fine circuit can be manufactured.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which a silver conductor circuit is printed on a polyethylene terephthalate film.

FIG. 2 is a plan view of a circuit board according to an embodiment of the present invention.

FIG. 3 is a plan view of an IC chip.

FIG. 4 is a schematic view showing a state where an IC chip is mounted on a chip mounting portion of a circuit board.

[Explanation of symbols]

1 Silver conductor circuit 2 Polyethylene terephthalate film 3 substrates 4 circuits 5 chip mounting part 6 circuit board 7 Test circuit 8 IC chips 9 Silicon substrate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01B 5/00 H01B 5/00 J H05K 1/09 H05K 1/09 A (31) Priority claim number Japanese Patent Application No. 7-140495 ( 32) Priority date June 7, 1995 (June 7, 1995) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 7-181473 (32) Priority date 1995 July 18 (July 18, 1995) (33) Priority claiming country Japan (JP) (72) Inventor Riichi Ono 3-3-1 Ayukawacho, Hitachi City, Ibaraki Prefecture Sakuragawa Sangyo Co., Ltd. (72 ) Inventor Yoshikatsu Mikami 2-1-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Hitaseikai Kogyo Co., Ltd. (72) Inventor Kuji Dogawachi 1150 Gozamiya, Shimodate-shi, Ibaraki Hitachi Chemical Co., Ltd. Yuki factory ( 72) Inventor Hiroshi Wada 138 Nishihara, Ashizaki, Oita, Hitachinaka City, Ibaraki Prefecture Address 1 Hitachi Chemical Co., Ltd. Yamazaki Factory (56) Reference JP-A-7-15022 (JP, A) JP-A-6-235006 (JP, A) JP-A-6-287762 (JP, A) Special Kaihei 1-315903 (JP, A) JP 6-338216 (JP, A) JP 6-325616 (JP, A) JP 6-223615 (JP, A) JP 62-80907 ( JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01B 1/00-1/24 H01B 5/00-5/16

Claims (18)

(57) [Claims] 1. A composite conductive powder comprising conductive powder having an aspect ratio of 6 to 11 and conductive powder having an aspect ratio of 5 or less. 2. A composite electroconductive powder according to claim 1, wherein the material of the conductive powder having an aspect ratio of 6 to 11 is silver, silver alloy or silver-coated conductors. 3. A composite conductive powder of the conductive powder having an aspect ratio of 6 to 11 is claimed in claim 1, wherein an aspect ratio of silver-coated conductor powder 6-11. 4. The composite conductive powder according to claim 3, wherein the silver-coated conductor powder having an aspect ratio of 6 to 11 is silver-coated copper powder or silver-coated copper alloy powder. Silver-coated conductor powder wherein the aspect ratio is 6 to 11 is, according to claim 3 or claim 4, wherein conductors are coated is silver-coated copper powder or silver-coated copper alloy powder is exposed Composite conductive powder of. 6. The composite conductive powder according to any one of claims 1 to 5 the material of the aspect ratio of 5 or less of the conductive powder is silver or a silver alloy. 7. The composite conductive powder according to claim 6 , wherein the conductive powder having an aspect ratio of 5 or less is reduced silver powder. 8. The composite conductive powder according to claim 6 , wherein the conductive powder having an aspect ratio of 5 or less is a conductive material having a hardness higher than that of silver or a silver alloy coated with silver. 9. A conductor having a hardness higher than that of silver or a silver alloy is C.
The composite conductive powder according to claim 8, which is o, Ni, Cr, Cu, W powder or an alloy powder thereof. 10. The composite conductive powder according to claim 8 , wherein the conductor having a hardness higher than that of silver or silver alloy is copper powder or copper alloy powder. 11. The conductive powder having an aspect ratio of 5 or less is a silver-coated copper powder in which the coated conductor is exposed.
The composite conductive powder according to any one of 8 to 10 . 12. The method of claim 1 composite conductive powder according to any one of 11, binder and solvent comprising conductive paste. 13. The conductive paste according to claim 12, wherein the composite conductive powder is contained in an amount of 85 to 93% by weight based on the solid content of the conductive paste. Composite conductive powder according to any one of 14. The method of claim 1 to 11, and also contains a binder and a solvent, to the conductive powder 95 to 50 wt% of the aspect ratio is 6 to 11, the aspect ratio is The conductive paste according to claim 12 or 13, which contains 5 to 50% by weight of a conductive powder of 5 or less. 15. The electrical circuit formed on the surface of the substrate using the conductive paste according to any one of claims 12-14. 16. The electric circuit according to claim 15 , wherein the specific resistance of the electric circuit formed on the surface of the base material is 25 μΩ · cm or less. 17. After forming a circuit pattern with a conductive paste according to the surface of the substrate to any of claims 12-14, pressurization, the preparation of the electric circuit, characterized in that the curing. 18. The specific resistance of the electric circuit formed on the surface of the base material is 25 μΩ · cm or less.
17. A method for manufacturing an electric circuit according to item 17 .