JP4363487B2 - Chargeable powder for circuit formation and multilayer wiring board using the same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chargeable powder for forming a circuit and a multilayer wiring board using the same, and more particularly to a chargeable powder for forming a circuit (toner) used for printing by electrophotography when forming a circuit pattern of the multilayered wiring board. And a multilayer wiring board using the same.

  Conventionally, a method of printing a circuit pattern on a dielectric layer constituting a multilayer wiring board is to make a paste by adjusting the viscosity with a solvent of a mixture of metal powder and adhesive, and then using this to screen printing There is a method of forming a predetermined circuit pattern on the dielectric layer. However, in this method, since a screen printing method using a dedicated mask corresponding to the circuit pattern is used, a mask is required for each circuit pattern. There is a problem that many processes and time are required, such as the production of an exposure master plate by the above method, the application of a photosensitive agent to a mask material, exposure and etching.

In order to solve this problem, in Patent Document 1, a manufacturing method for forming a charged powder for circuit formation as a desired circuit pattern on a dielectric layer using electrostatic force as in normal electrophotography Has been proposed. Patent Document 2 proposes a charged powder for circuit formation used in this manufacturing method. FIG. 10 shows a cross-sectional view of a conventional chargeable powder for circuit formation. The conductive powder 100 for circuit formation is a conductive metal powder 101 serving as a core substance, for example, spherical silver particles having an average particle diameter of 7.5 μm, and thermal melting serving as an outer wall formed around the conductive metal powder 101. A charge control agent 103, for example, an azo metal-containing dye powder having an average particle diameter of 0.6 μm, on the surface of the heat-meltable resin 102, for example, a polymethylmethacrylate resin having an average particle diameter of 0.4 μm. Has a fixed structure. Then, as a method for producing the chargeable powder 100 for circuit formation, first, the conductive metal powder 101 and the fine particles of the heat-meltable resin 102 are mixed, and the fine particles of the heat-meltable resin 102 are statically mixed with the conductive metal powder 101. It is attached by electric power. Next, a mechanical impact force is applied thereto, the fine particles of the heat-meltable resin 102 are deformed by the heat generated thereby, and the outer wall of the heat-meltable resin 102 is formed on the conductive metal powder 101. Next, this is mixed with the fine particles of the charge control agent 103, and the fine particles of the charge control agent 103 are adhered to the outer wall made of the heat-meltable resin 102 by electrostatic force. It is fixed to the outer wall made of the heat-meltable resin 102.
JP-A-2-257696 Japanese Patent Laid-Open No. 4-237062

  However, in the conventional charged powder for circuit formation, the conductive metal powder has a substantially constant particle size so that the average particle size becomes a desired constant value. Therefore, when the circuit pattern is formed using the chargeable powder for circuit formation, since the filling of the conductive metal powder becomes rough in the circuit pattern, the sheet resistance of the circuit pattern is high, and the loss of the circuit pattern is increased. There has been a problem that it cannot be used for a multilayer wiring board intended for a high frequency region.

  The present invention has been made to solve such problems, and is capable of densely filling a conductive metal powder in a circuit pattern, and a multilayer wiring board using the same. The purpose is to provide.

In order to solve the above-mentioned problems, the charged powder for circuit formation of the present invention is a charged powder for circuit formation used for printing a circuit pattern on a substrate by electrophotography, and has a first conductive property. A chargeable powder composed of a conductive metal powder, a first resin layer made of a heat-meltable resin formed around the first conductive metal powder, and a charge control agent fixed to the surface of the first resin layer; A second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, a first resin layer made of a hot-melt resin formed around the second conductive metal powder, and the first resin e Bei a second charged powder composed of the charge control agent is adhered to the surface of the layer, a, respectively, as the charging characteristics are substantially the same adjustment with the second charged powder to the first chargeable powder The first chargeable powder and the second chargeable powder at a desired ratio. Combined, characterized by comprising.

A charged powder for circuit formation used when a circuit pattern is printed on a substrate by electrophotography, and is formed around the first conductive metal powder and the first conductive metal powder. A first chargeable powder composed of a second resin layer comprising a heat-meltable resin and a charge control agent, a second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, and the first e Bei a second charged powder composed of the second resin layer formed of a second conductive metal powder hot-melt resin formed around the charge control agent, wherein the first charged powder and the second The charging characteristics of the chargeable powder are adjusted so as to be substantially the same, and the first chargeable powder and the second chargeable powder are mixed at a desired ratio .

  Further, the first chargeable powder and / or the second chargeable powder includes an adhesion reinforcing agent.

  The multilayer wiring board of the present invention is characterized in that a circuit pattern is printed on a ceramic green sheet by electrophotography, and the ceramic green sheet on which the circuit pattern is printed is laminated.

  According to the charged powder for circuit formation of the present invention, since the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder are included, the circuit pattern is formed on the substrate. When the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder enters the gap formed between the first conductive metal powders, the conductive metal powder in the circuit pattern is closely packed. Can be.

  According to the multilayer wiring board of the present invention, using the charged powder for circuit formation including the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, A conductive metal powder in a circuit pattern constituting a multilayer wiring board after firing because a circuit pattern is printed on a ceramic green sheet by electrophotography, and then the ceramic green sheets are laminated and formed by a normal manufacturing method. The packing of can be made dense.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 2 shows a cross-sectional view of the first embodiment of the charged powder for circuit formation according to the present invention. The chargeable powder 20 for circuit formation includes a first chargeable powder 21 composed of a first conductive metal powder 11, a charge control agent 13, an adhesion strengthening agent 14 and a heat-meltable resin 15, and a first conductive metal powder. A second conductive metal powder 12 having a smaller average particle size, a charge control agent 13, an adhesion reinforcing agent 14, and a second chargeable powder 22 composed of a hot-melt resin 15.

  In the first chargeable powder 21, a first resin layer 23 composed of the adhesion reinforcing agent 14 and the heat-meltable resin 15 is formed around the first conductive metal powder 11, and the surface of the first resin layer 23. The charge control agent 13 is fixed to the structure. Further, the second chargeable powder 22 is formed with a first resin layer 23 made of the adhesion reinforcing agent 14 and the heat-meltable resin 15 around the second conductive metal powder 12, and the surface of the first resin layer 23. The charge control agent 13 is fixed to the structure.

  Here, the specific manufacturing method of the chargeable powder 20 for circuit formation is demonstrated. In the first chargeable powder 21, first, spherical copper particles having an average particle diameter of 5.0 μm that is the first conductive metal powder 11, silica that is the adhesion reinforcing agent 14, and styrene that is the hot-melt resin 15. The acrylic copolymer is mixed at a weight ratio of 1:18 and finely pulverized particles are mixed at a weight ratio of 80:19, and the first conductive metal powder 11 is composed of the adhesion reinforcing agent 14 and the hot-melt resin 15. The particles are attached by electrostatic force.

  Next, a process in which a mechanical impact force is applied to the first conductive metal powder 11 to which particles composed of the adhesion strengthening agent 14 and the heat-meltable resin 15 are attached is performed around the first conductive metal powder 11. To obtain an intermediate formed with the first resin layer 23 composed of the adhesion reinforcing agent 14 and the heat-meltable resin 15.

  Next, a weight ratio of the intermediate in which the first resin layer 23 made of the adhesion reinforcing agent 14 and the heat-meltable resin 15 is formed around the first conductive metal powder 11 and the azo metal dye that is the charge control agent 13. After mixing at 99: 1, a process of applying mechanical impact force is performed, and the first chargeable powder 21 having an average particle diameter of 11.2 μm in which the charge control agent 13 is fixed to the surface of the intermediate, that is, the first conductive A first resin layer 23 made of an adhesion reinforcing agent 14 and a heat-meltable resin 15 is formed around the metal powder 11, and a first chargeable powder 21 having the charge control agent 13 fixed on the surface thereof is obtained.

  On the other hand, in the second chargeable powder 22, first, spherical copper particles having an average particle diameter of 3.0 μm as the second conductive metal powder 12, silica and the hot-melt resin 15 as the adhesion reinforcing agent 14. A certain styrene acrylic copolymer is mixed at a weight ratio of 1:28 and finely pulverized particles are mixed at a weight ratio of 70:29, and the second conductive metal powder 12 is composed of an adhesion reinforcing agent 14 and a hot-melt resin 15. The particles to be adhered are attached by electrostatic force.

  Next, a process in which a mechanical impact force is applied to the second conductive metal powder 12 to which particles composed of the adhesion strengthening agent 14 and the heat-meltable resin 15 are adhered is performed around the second conductive metal powder 12. To obtain an intermediate formed with the first resin layer 23 composed of the adhesion reinforcing agent 14 and the heat-meltable resin 15.

  Next, a weight ratio of the intermediate in which the first resin layer 23 made of the adhesion reinforcing agent 14 and the heat-meltable resin 15 is formed around the second conductive metal powder 12 and the azo metal dye that is the charge control agent 13. After mixing at 99: 1, a mechanical impact force is applied, and the charge control agent 13 is fixed on the surface of the intermediate, and the second charged powder 22 having an average particle size of 5.6 μm, that is, second conductive A first resin layer 23 made of an adhesion reinforcing agent 14 and a heat-meltable resin 15 is formed around the metal powder 12, and a second chargeable powder 22 having a charge control agent 13 fixed on the surface thereof is obtained.

  At this time, the first conductive metal powder 11 constituting the first chargeable powder 21 is charged so that the specific charge, which is the charge characteristic of the first and second chargeable powders 21 and 22, is -15 μC / g. The component ratio of the control agent 13, the adhesion reinforcing agent 14 and the hot melt resin 15, the second conductive metal powder 12 constituting the second chargeable powder 22, the charge control agent 13, the adhesion strengthening agent 14 and the hot melt resin The component ratio of 15 is adjusted and mixed to obtain the charged powder 20 for circuit formation.

  The specific charges of the first and second chargeable powders 21 and 22 are the same as those of the first conductive metal powder 11, the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 while measuring the specific charge. By adjusting the component ratio and the second conductive metal powder 12, the charge control agent 13, the adhesion reinforcing agent 14, and the hot-melt resin 15, it is possible to obtain a desired value.

  According to the above-described charged powder for circuit formation of the first embodiment, since it includes the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, When the circuit pattern is formed on the printed matter, the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder enters a gap formed between the first conductive metal powders. The powder filling can be made dense. Therefore, the sheet resistance of the circuit pattern can be reduced and the loss of the circuit pattern can be reduced.

  In addition, since the first chargeable powder containing the first conductive metal powder and the second chargeable powder containing the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, the first charge By setting the ratio between the conductive powder and the second charged powder to a desired value, the ratio between the first conductive metal powder and the second conductive metal powder can be set to a desired value. Therefore, the first conductive metal powder and the second conductive metal are designed at the stage of designing the charged powder for circuit formation so that as much second conductive metal powder as possible can enter the gap formed between the first conductive metal powders. The ratio with the powder can be optimized.

  The circuit-forming chargeable powder includes a first chargeable powder containing the first conductive metal powder and a second chargeable powder containing a second conductive metal powder having an average particle size smaller than that of the first conductive metal powder. Therefore, by simply mixing the first and second charged powders, the first and second conductive metal powders having different average particle diameters can be contained in the charged powder for circuit formation. The manufacturing process of the charged powder for circuit formation is simplified, and the cost is reduced.

  Furthermore, since the charge control agent is fixed to the surfaces of the first and second chargeable powders, a chargeable powder for circuit formation having uniform chargeability can be obtained. Therefore, by using this chargeable powder for circuit formation, the chargeability can be easily controlled, the printability is improved, and it is possible to cope with the formation of a circuit pattern with a narrow pitch. Formation is possible.

  Moreover, the component ratio of the 1st electroconductive metal powder which comprises 1st electroconductive powder, a charge control agent, an adhesion strengthening agent, and a thermomeltable resin, 2nd electroconductive metal powder which comprises 2nd electroconductive powder, charge Since the specific charge of the first chargeable powder and the specific charge of the second chargeable powder are made substantially the same by selecting the component ratio of the control agent, the adhesion enhancer and the heat-meltable resin, With the constant electric field formed, the first and second chargeable powders are attracted to the photoreceptor without being selected. Therefore, since almost all of the first and second charged powders can be used for printing the circuit pattern, more gaps are formed between the first conductive metal powders when forming the circuit pattern on the substrate. The second conductive metal powder can enter, the filling of the conductive metal powder in the circuit pattern can be made denser, and the specific resistance of the circuit pattern can be further reduced.

  A description will be given of another specific method for manufacturing the circuit-forming chargeable powder 20 (FIG. 2) of the first embodiment. In the first chargeable powder 21, first, spherical copper particles having an average particle diameter of 12.0 μm that is the first conductive metal powder 11, silica that is the adhesion reinforcing agent 14, and styrene that is the hot-melt resin 15. The acrylic copolymer is mixed at a weight ratio of 1:13 and finely pulverized particles are mixed at a weight ratio of 85:14, and the first conductive metal powder 11 is composed of the adhesion reinforcing agent 14 and the heat-meltable resin 15. The particles are attached by electrostatic force.

  Next, a process in which a mechanical impact force is applied to the first conductive metal powder 11 to which particles composed of the adhesion strengthening agent 14 and the heat-meltable resin 15 are attached is performed around the first conductive metal powder 11. To obtain an intermediate formed with the first resin layer 23 composed of the adhesion reinforcing agent 14 and the heat-meltable resin 15.

  Next, a weight ratio of the intermediate in which the first resin layer 23 made of the adhesion reinforcing agent 14 and the heat-meltable resin 15 is formed around the first conductive metal powder 11 and the azo metal dye that is the charge control agent 13. After mixing with 99: 1, a process of applying a mechanical impact force is performed, and the first chargeable powder 21 having an average particle diameter of 15.2 μm in which the charge control agent 13 is fixed to the surface of the intermediate, that is, the first conductivity A first resin layer 23 made of an adhesion reinforcing agent 14 and a heat-meltable resin 15 is formed around the metal powder 11, and a first chargeable powder 21 having a charge control agent 13 fixed on the surface thereof is obtained.

  On the other hand, in the second chargeable powder 22, first, spherical copper particles having an average particle diameter of 5.0 μm as the second conductive metal powder 12, silica and the heat-meltable resin 15 as the adhesion reinforcing agent 14. A certain styrene acrylic copolymer is mixed at a weight ratio of 1:22 and finely pulverized particles are mixed at a weight ratio of 76:23, and the second conductive metal powder 12 is composed of the adhesion reinforcing agent 14 and the hot-melt resin 15. The particles to be adhered are attached by electrostatic force.

  Next, a process in which mechanical impact force is applied to the second conductive metal powder 12 to which particles composed of the adhesion strengthening agent 14 and the heat-meltable resin 15 are adhered is performed around the second conductive metal powder 15. An intermediate having the first resin layer 23 made of the heat-meltable resin 12 formed thereon is obtained.

  Next, a weight ratio of the intermediate in which the first resin layer 23 made of the adhesion reinforcing agent 14 and the heat-meltable resin 15 is formed around the second conductive metal powder 12 and the azo metal dye that is the charge control agent 13. After mixing at 99: 1, a process of applying a mechanical impact force is performed, and the second chargeable powder 22 having an average particle diameter of 11.2 μm in which the charge control agent 13 is fixed on the surface of the intermediate, that is, the second conductive A first resin layer 23 made of an adhesion reinforcing agent 14 and a heat-meltable resin 15 is formed around the metal powder 12 to obtain a second chargeable powder 22 having the charge control agent 13 fixed on the surface thereof.

  In this case, since the average particle size of the first and second conductive metal powders is increased, the film thickness of the circuit pattern formed by electrophotography using this charged powder 20 for circuit formation is 3 The sheet resistance of the circuit pattern can be further reduced. That is, by increasing the average particle size of the first and second conductive metal powders, the film thickness of the circuit pattern can be increased, and accordingly, the sheet resistance of the circuit pattern can be further reduced. .

FIG. 3 shows a cross-sectional view of a second embodiment of the charged powder for circuit formation according to the present invention.
Similarly to the circuit-forming chargeable powder 20 of the first embodiment, the circuit-forming chargeable powder 30 is composed of the first conductive metal powder 11, the charge control agent 13, the adhesion reinforcing agent 14, and the hot-melt resin 15. A first chargeable powder 31 configured, and a second chargeable powder 32 formed of the second conductive metal powder 12, the charge control agent 13, the adhesion reinforcing agent 14, and the hot-melt resin 15 are provided.

  The first chargeable powder 31 has a structure in which a second resin layer 33 composed of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 is formed around the first conductive metal powder 11. . The second chargeable powder 32 has a structure in which a second resin layer 33 made of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 is formed around the second conductive metal powder 12. .

  Here, the specific manufacturing method of the chargeable powder 30 for circuit formation is demonstrated. For the first chargeable powder 31, first, spherical copper particles having an average particle diameter of 5.0 μm as the first conductive metal powder 11, an azo metal dye as the charge control agent 13, and an adhesion reinforcing agent 14. A certain silica and a styrene acrylic copolymer which is a heat-meltable resin 15 are mixed at a weight ratio of 1: 1: 18, and finely pulverized particles are mixed at a weight ratio of 80:20 to form the first conductive metal powder 11. Particles composed of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 are attached by electrostatic force.

  Next, a process in which mechanical impact force is applied to the first conductive metal powder 11 to which particles composed of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 are attached is performed. The 1st chargeable powder 31 with an average particle diameter of 11.2 micrometers in which the 2nd resin layer 33 which consists of the charge control agent 13, the adhesion strengthening agent 14, and the thermomeltable resin 15 was formed in the circumference | surroundings of the conductive metal powder 11 is obtained.

  On the other hand, for the second chargeable powder 32, first, spherical copper particles having an average particle diameter of 3.0 μm as the second conductive metal powder 12, an azo metal dye as the charge control agent 13, and an adhesion reinforcing agent. 14 and a styrene acrylic copolymer as a heat-meltable resin 15 are mixed at a weight ratio of 1: 1: 22, and finely pulverized particles are mixed at a weight ratio of 76:24 to obtain a second conductive metal powder. The particles composed of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 are attached to 12 by electrostatic force.

  Next, a process in which a mechanical impact force is applied to the second conductive metal powder 12 to which particles composed of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 are attached is performed. A second chargeable powder 32 having an average particle size of 5.6 μm is obtained in which the second resin layer 33 made of the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 is formed around the metal powder 12.

  At this time, in the same manner as the circuit-forming chargeable powder 20 of the first embodiment, the first and second chargeable powders 31 and 32 are charged so that the specific charge, which is the charge characteristic, becomes -15 μC / g. Component ratios of the first conductive metal powder 11, the charge control agent 13, the adhesion reinforcing agent 14, and the heat-meltable resin 15 constituting the one chargeable powder 31, and the second conductive metal constituting the second chargeable powder 32. The powder 12, the charge control agent 13, the adhesion reinforcing agent 14, and the component ratio of the heat-meltable resin 15 are adjusted and mixed to obtain a chargeable powder 30 for circuit formation.

  According to the charged powder for circuit formation of the second embodiment described above, the second resin layer made of the charge control agent, the adhesion reinforcing agent and the heat-meltable resin is formed around the first conductive metal powder. Thus, it is not necessary to fix the charge control agent to the outer peripheral portions of the first and second chargeable powders by another process, and the manufacturing process of the circuit forming chargeable powder can be simplified. Therefore, cost reduction of the chargeable powder for circuit formation is realizable.

  Actually, the film thickness of the circuit pattern formed by electrophotography using the circuit forming charged powders 20 and 30 of the first and second embodiments is 2.3 to 2.8 μm, and the sheet resistance is 4. 5 to 5.5 mΩ / □, and the sheet resistance of the circuit pattern is about one-half that of the conventional charged powder for circuit formation 100 (FIG. 10), and the circuit pattern sheet obtained by screen printing. The value was almost equal to the resistance.

  FIG. 8 shows a configuration diagram of an electrophotographic system used when forming a circuit pattern on a substrate. The circuit pattern is formed on the substrate by a charging process in which the surface of the photoconductor 82 is charged by the corona charger 81, and the surface of the photoconductor 82 rotating in the direction of arrow A is irradiated with a laser beam 83 to form a desired latent image. An exposure process for forming a pattern (not shown), a developing process for electrostatically adsorbing the chargeable powders 20 and 30 for circuit formation (FIGS. 2 and 3) to the latent image pattern on the surface of the photoreceptor 82 by the supply means 84; From the back surface of the substrate 85, the transfer device 86 gives a charge having a polarity opposite to that of the circuit-forming charged powders 20 and 30, and the circuit-forming charged powders 20 and 30 developed on the latent image pattern are applied to the substrate 85. A transfer step for transferring to the substrate, a fixing step for fixing the charged powders 20 and 30 for circuit formation transferred onto the substrate 85 by irradiation of the flash lamp 87, and a heat melting property for constituting the charged powders 20 and 30 for circuit formation. Skip fat 15, and a firing step of forming a circuit pattern (not shown) on the substrate 85.

  During the firing process, the heat-meltable resin 15 constituting the circuit-forming chargeable powders 20 and 30 flies by the heat of the firing furnace or the like, so the circuit pattern is composed only of the first and second conductive metal powders. The second conductive metal powder enters the gap formed between the first conductive metal powders.

  FIG. 9 shows a cross-sectional view of one embodiment of a multilayer wiring board according to the present invention. The multilayer wiring board 90 includes first to third ceramic green sheets 91a to 91c. Then, on the first and second ceramic green sheets 91a and 91b, the circuit forming charged powders 20 and 30 of the first and second embodiments described above are used, and the circuit is produced by the electrophotographic system of FIG. The patterns 92a and 92b are printed. Next, the first to third ceramic green sheets 91a to 91c are stacked, pressure is applied, and they are integrally molded and then fired.

  The circuit patterns 92a and 92b on the first and second ceramic green sheets 91a and 91b are connected by a via hole 93. The via hole 93 is formed by an existing technique. For example, there is a method of press-fitting a conductor for each via hole using a conductor drawing device. In this case, if the via holes 93 are formed after the circuit patterns 92a and 92b are formed by electrophotography, the powder may damage the nozzle of the drawing machine. Therefore, the via holes are formed before the circuit patterns 92a and 92b are formed. 93 is preferably formed.

  According to the multilayer wiring board described above, using the chargeable powder for circuit formation including the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, The circuit pattern is printed on the ceramic green sheet by photographic method, and then the ceramic green sheets are laminated to form a multilayer wiring board. After firing, filling the conductive metal powder in the circuit pattern constituting the multilayer wiring board Can be dense.

  Therefore, since the sheet resistance and loss of the circuit pattern constituting the multilayer wiring board can be reduced, the multilayer wiring board constituted by this circuit pattern can be used in the high frequency region.

  In the first and second embodiments described above, the case where copper is used as the conductive metal powder has been described. However, the simple substance of gold, silver, platinum, nickel, palladium, tungsten and molybdenum, their oxides, or The same effect can be obtained even when an alloy composed of two or more of these is used.

  Moreover, although the case where a styrene acrylic copolymer was used for a heat-meltable resin was described, the heat-meltable resin is also called a thermoplastic resin, and a polymethyl methacrylate resin, a cross-linked acrylic resin, a polystyrene resin, a polyethylene resin, a fluororesin, The same effect can be obtained by using a simple substance such as vinylidene fluoride resin and benzoguanamine resin or a mixture of two or more of these.

  Further, the case where an azo metal-containing dye is used as the charge control agent has been described. However, the chlorinated paraffin, the chlorinated polyester, the polyester having excess acid groups, and the sulfonylamine naphthene of copper phthalocyanine, which are charge control agents for negative charge, have been described. The same effect can be obtained by using a simple substance such as an acid metal salt, a metal salt of a fatty acid and a resin acid soap, or a mixture of two or more of these.

  Moreover, although the case where the silica which is glass is used for the adhesion reinforcing agent has been described, a glass composed of a simple substance such as borosilicate glass, soda lime, lead glass and aluminosilicate glass or a mixture of two or more of these, or alumina, The same effect can be obtained by using ceramics such as ferrite.

  Furthermore, the same effect can be obtained even if the first and second conductive metal powders are second agglomerated powders obtained by aggregating a plurality of first powders.

  In the second embodiment, the structure in which the charge control agent is fixed to the outer peripheral portions of the first and second chargeable powders, that is, the second made of the charge control agent, the adhesion reinforcing agent, and the heat-meltable resin. The same effect can be obtained even if the charge control agent is fixed on the surface of the resin layer.

Further, as shown in the first and second embodiments, it is preferable that an adhesion reinforcing agent is included in the chargeable powder for circuit formation. In particular, when the adhesion reinforcing agent is included in the chargeable powder for circuit formation, the adhesion enhancing agent is a conductive metal that forms the circuit pattern when firing the ceramic green sheet on which the circuit pattern is formed. It will play a role in strengthening the adhesion between the powder and the fired ceramic sheet.
Therefore, since the adhesive strength between the fired ceramic sheet and the circuit pattern is improved after firing, it is possible to prevent the circuit pattern from being peeled off from the ceramic sheet.
<Reference example>
FIG. 1 shows a cross-sectional view of a first reference example of a charged powder for circuit formation according to the present invention. The circuit-forming chargeable powder 10 is obtained by thermally melting the first conductive metal powder 11, the second conductive metal powder 12 having an average particle size smaller than that of the first conductive metal powder 11, the charge control agent 13 and the adhesion reinforcing agent 14. The structure is uniformly dispersed in the conductive resin 15.

  Here, the specific manufacturing method of the chargeable powder 10 for circuit formation is demonstrated. First, spherical copper particles having an average particle diameter of 0.8 μm as the first conductive metal powder 11, spherical copper particles having an average particle diameter of 0.4 μm as the second conductive metal powder 12, and charge control The azo metal dye which is the agent 13, the silica which is the adhesion reinforcing agent 14, and the styrene acrylic copolymer which is the hot-melt resin 15 were mixed in a weight ratio of 30: 50: 1: 1: 118.

  Next, the mixture is heat-melted and kneaded with a kneader, and coarsely pulverized with a cutter mill and finely pulverized with a jet mill. Subsequently, the chargeable powder 10 for circuit formation with an average particle diameter of 8.0 micrometers is obtained by airflow classification.

  According to the charged powder for circuit formation of the first reference example described above, the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder are included. When the circuit pattern is formed on the printed matter, the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder enters a gap formed between the first conductive metal powders. The powder filling can be made dense. Therefore, the sheet resistance of the circuit pattern can be reduced and the loss of the circuit pattern can be reduced.

FIG. 4 shows a cross-sectional view of a second reference example of the charged powder for circuit formation according to the present invention.
In the circuit-forming chargeable powder 40, a third resin layer 41 composed of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around the first conductive metal powder 11. The charge control agent 13 is fixed on the surface.

  Here, the specific manufacturing method of the chargeable powder 40 for circuit formation is demonstrated. First, spherical copper particles having an average particle diameter of 3.0 μm as the first conductive metal powder 11, spherical copper particles having an average particle diameter of 0.5 μm as the second conductive metal powder 12, and heat melting properties. The styrene acrylic copolymer, which is the resin 15, is mixed at a weight ratio of 15:19 and finely pulverized particles are mixed at a weight ratio of 65:34, and the first conductive metal powder 11 and the second conductive metal powder 12 and the heat are mixed. The particles composed of the meltable resin 15 are adhered by electrostatic force.

  Next, the first conductive metal powder 11 is subjected to a process of applying a mechanical impact force to the first conductive metal powder 11 to which particles composed of the second conductive metal powder 12 and the heat-meltable resin 15 are adhered. An intermediate in which a third resin layer 41 made of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around 11 is obtained.

  Next, the intermediate in which the third resin layer 41 is formed around the first conductive metal powder 11 and the azo metal dye as the charge control agent 13 are mixed at a weight ratio of 99: 1, and then the mechanical impact force. And the second conductive metal powder 12 and the hot-melt resin 15 around the first conductive metal powder 11, that is, the charge powder 40 for circuit formation in which the charge control agent 13 is fixed to the surface of the intermediate. The third resin layer 41 is formed, and the chargeable powder 40 for circuit formation having the charge control agent 13 fixed on the surface thereof is obtained.

  According to the charged powder for circuit formation of the second reference example described above, the third resin layer made of the second conductive metal powder and the heat-meltable resin is formed around the first conductive metal powder. Many second conductive metal powders are arranged around the first conductive metal powder. Therefore, when forming the circuit pattern on the substrate, more second conductive metal powder enters a gap formed between the first conductive metal powders, and the conductive metal powder is more densely filled in the circuit pattern. be able to.

  As a result, since the sheet resistance and loss of the circuit pattern can be further reduced, it becomes possible to use the multilayer wiring board constituted by this circuit pattern in a higher frequency region.

  In addition, since the charge control agent is fixed on the surface of the circuit-forming chargeable powder, a circuit-forming chargeable powder having uniform chargeability can be obtained. Therefore, by using this chargeable powder for circuit formation, the chargeability can be easily controlled, the printability is improved, and it is possible to cope with the formation of a circuit pattern with a narrow pitch. Formation is possible.

  FIG. 5 shows a cross-sectional view of a third reference example of the charged powder for circuit formation according to the present invention. In the circuit-forming chargeable powder 50, a third resin layer 41 composed of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around the first conductive metal powder 11, and the third resin layer 41 is formed. The fourth resin layer 51 made of the heat-meltable resin 15 is formed around the surface of the substrate, and the charge control agent 13 is fixed to the surface of the fourth resin layer 51.

  Here, the specific manufacturing method of the chargeable powder 50 for circuit formation is demonstrated. First, spherical copper particles having an average particle diameter of 3.0 μm as the first conductive metal powder 11, spherical copper particles having an average particle diameter of 0.5 μm as the second conductive metal powder 12, and heat melting properties. The styrene acrylic copolymer as the resin 15 is mixed at a weight ratio of 15:14 and finely pulverized particles are mixed at a weight ratio of 65:29, and the first conductive metal powder 11 and the second conductive metal powder 12 and the heat are mixed. The particles composed of the meltable resin 15 are adhered by electrostatic force.

  Next, the first conductive metal powder 11 is subjected to a process of applying a mechanical impact force to the first conductive metal powder 11 to which particles composed of the second conductive metal powder 12 and the heat-meltable resin 15 are adhered. A first intermediate in which a third resin layer 41 made of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around 11 is obtained.

  Next, the first intermediate in which the third resin layer 41 is formed around the first conductive metal powder 11 and the styrene acrylic copolymer as the heat-meltable resin 15 are mixed at a weight ratio of 94: 5, The particles of the hot-melt resin 15 are adhered to one intermediate by electrostatic force.

  Next, a process in which a mechanical impact force is applied to the first intermediate having the particles of the heat-meltable resin 15 attached thereto to form a fourth resin layer 51 made of the heat-meltable resin 15 on the first intermediate. A second intermediate is obtained.

  Next, the second intermediate in which the fourth resin layer 51 is formed on the first intermediate and the azo metal dye that is the charge control agent 13 are mixed at a weight ratio of 99: 1, and then a mechanical impact force is applied. And the second conductive metal powder 12 and the heat around the first conductive metal powder 11 of the conductive metal powder, that is, the conductive powder 50 for circuit formation in which the charge control agent 13 is fixed to the surface of the second intermediate. A third resin layer 41 made of a meltable resin 15 and a fourth resin layer 51 made of a heat-meltable resin 15 are formed, and a chargeable powder 50 for circuit formation in which the charge control agent 13 is fixed on the surface thereof is obtained.

  According to the above-mentioned chargeable powder for circuit formation of the third reference example, since the fourth resin layer made of a heat-meltable resin is formed between the third resin layer and the charge control agent, the conductive metal It is possible to prevent the powder from appearing on the surface of the chargeable powder for circuit formation. Accordingly, deterioration of the chargeability due to the conductive metal powder can be prevented, so that the chargeability of the chargeable powder for circuit formation can be improved. As a result, the printability is further improved, and the circuit having a narrower pitch. It is possible to cope with pattern formation.

  FIG. 6 shows a sectional view of a fourth reference example of the charged powder for circuit formation according to the present invention. In the circuit-forming chargeable powder 60, a third resin layer 41 composed of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around the first conductive metal powder 11. A structure in which a fifth resin layer 61 made of the charge control agent 13 and the heat-meltable resin 15 is formed around is formed.

  Here, the specific manufacturing method of the chargeable powder 60 for circuit formation is demonstrated. First, spherical copper particles having an average particle diameter of 3.0 μm as the first conductive metal powder 11, spherical copper particles having an average particle diameter of 0.5 μm as the second conductive metal powder 12, and heat melting properties. The styrene acrylic copolymer as the resin 15 is mixed at a weight ratio of 15:14 and finely pulverized particles are mixed at a weight ratio of 65:29, and the first conductive metal powder 11 and the second conductive metal powder 12 and the heat are mixed. The particles composed of the meltable resin 15 are adhered by electrostatic force.

  Next, the first conductive metal powder 11 is subjected to a process of applying a mechanical impact force to the first conductive metal powder 11 to which particles composed of the second conductive metal powder 12 and the heat-meltable resin 15 are adhered. An intermediate in which a third resin layer 41 made of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around 11 is obtained.

  Next, an intermediate in which a third resin layer 41 made of the second conductive metal powder 12 and the heat-meltable resin 15 is formed around the first conductive metal powder 11, an azo metal dye that is the charge control agent 13, and A styrene acrylic copolymer, which is a heat-meltable resin 15, is mixed at a weight ratio of 1: 5, and finely pulverized particles are mixed at a weight ratio of 94: 6. The constituted particles are adhered by electrostatic force.

  Next, a circuit in which a fifth resin layer 61 is formed around the intermediate by performing a process of applying a mechanical impact force to the intermediate formed by adhering particles composed of the charge control agent 13 and the heat-meltable resin 15. The forming chargeable powder 60, that is, the third resin layer 41 made of the second conductive metal powder 12 and the heat-meltable resin 15 around the first conductive metal powder 11, and the charge control agent 13 and the heat-meltable resin 15. A chargeable powder 60 for circuit formation in which the fifth resin layer 61 made of is formed is obtained.

  According to the chargeable powder for circuit formation of the fourth reference example described above, the fifth resin layer made of the heat-meltable resin and the charge control agent is formed around the third resin layer. This eliminates the need to fix the charge control agent on the surface of the circuit forming chargeable powder. Therefore, since the manufacturing process of the circuit-forming chargeable powder can be simplified, the cost of the circuit-forming chargeable powder can be reduced.

  FIG. 7 shows a cross-sectional view of a fifth reference example of the chargeable powder for circuit formation according to the present invention. The circuit-forming chargeable powder 70 has a structure in which a sixth resin layer 71 made of the second conductive metal powder 12, the charge control agent 13 and the heat-meltable resin 15 is formed around the first conductive metal powder 11. Make.

  Here, the specific manufacturing method of the chargeable powder 70 for circuit formation is demonstrated. First, spherical copper particles having an average particle diameter of 3.0 μm as the first conductive metal powder 11, spherical copper particles having an average particle diameter of 0.5 μm as the second conductive metal powder 12, a charge control agent 13 and a styrene acrylic copolymer which is a heat-meltable resin 15 are mixed at a weight ratio of 15: 1: 1 and finely pulverized particles are mixed at a weight ratio of 65:35. Particles composed of the conductive metal powder 12, the charge control agent 13, and the heat-meltable resin 15 are adhered by electrostatic force.

  Next, a process of applying a mechanical impact force to the first conductive metal powder 11 to which particles composed of the second conductive metal powder 12, the charge control agent 13, and the heat-meltable resin 15 are attached is performed. A chargeable powder for circuit formation 70 is obtained in which a sixth resin layer 71 made of the second conductive metal powder 12, the charge control agent 13, and the heat-meltable resin 15 is formed around the first conductive metal powder 11.

  According to the charged powder for circuit formation of the fifth reference example described above, only the sixth resin layer made of the second conductive metal powder, the charge control agent, and the heat-meltable resin is provided around the first conductive metal powder. Therefore, the second conductive metal powder and the charge control agent can be disposed around the first conductive metal powder in one step. Therefore, since the manufacturing process of the circuit-forming chargeable powder can be simplified, the cost of the circuit-forming chargeable powder can be reduced.

  According to the charged powder for circuit formation of claim 1 of the present invention, the circuit pattern includes the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder. When the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder enters the gap formed between the first conductive metal powders, the conductive metal powder in the circuit pattern is closely packed. Can be. Therefore, the sheet resistance of the circuit pattern can be reduced and the loss of the circuit pattern can be reduced.

  In addition, since the first chargeable powder containing the first conductive metal powder and the second chargeable powder containing the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, the first charge By setting the ratio between the conductive powder and the second charged powder to a desired value, the ratio between the first conductive metal powder and the second conductive metal powder can be set to a desired value. Therefore, the first conductive metal powder and the second conductive metal are designed at the stage of designing the charged powder for circuit formation so that as much second conductive metal powder as possible can enter the gap formed between the first conductive metal powders. The ratio with the powder can be optimized.

  Further, since the first chargeable powder containing the first conductive metal powder and the second chargeable powder containing the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder, Since the first and second conductive metals having different average particle diameters can be contained in the circuit-forming charged powder simply by mixing the second charged powder, the process for producing the circuit-forming charged powder Is simplified and the cost is reduced.

  Furthermore, since the charge control agent is fixed to the surfaces of the first and second chargeable powders, a chargeable powder for circuit formation having uniform chargeability can be obtained. Therefore, by using this chargeable powder for circuit formation, the chargeability can be easily controlled, the printability is improved, and it is possible to cope with the formation of a circuit pattern with a narrow pitch. Formation is possible.

  According to the charged powder for forming a circuit of claim 2, since the first conductive metal powder and the second conductive metal powder having an average particle size smaller than the first conductive metal powder are included, a circuit pattern is formed. In this case, the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder enters a gap formed between the first conductive metal powders, so that the conductive metal powder is densely filled in the circuit pattern. Can do. Therefore, the sheet resistance of the circuit pattern can be reduced and the loss of the circuit pattern can be reduced.

  In addition, since the second resin layer made of the charge control agent, the adhesion strengthening agent, and the heat-meltable resin is formed around the first conductive metal powder, the charge control agent is separated into the first and second charges by separate steps. It becomes unnecessary to adhere to the outer periphery of the conductive powder, and the manufacturing process of the charged powder for circuit formation can be simplified. Therefore, cost reduction of the chargeable powder for circuit formation is realizable.

  According to the chargeable powder for forming a circuit of the third aspect, since the charge characteristics of the first chargeable powder and the second chargeable powder are substantially the same, the first charge powder and the second chargeable powder have the first electric field formed on the photoconductor. And the second chargeable powder is attracted to the photoreceptor without being selected. Therefore, since almost all of the first and second charged powders can be used for printing the circuit pattern, more gaps are formed between the first conductive metal powders when forming the circuit pattern on the substrate. The second conductive metal powder can enter, the filling of the conductive metal powder in the circuit pattern can be made denser, and the specific resistance of the circuit pattern can be further reduced.

  According to the chargeable powder for circuit formation according to claim 4, when the adhesion reinforcing agent fires the ceramic green sheet on which the circuit pattern is formed, the conductive metal powder that forms the circuit pattern and the fired ceramic sheet Plays a role in strengthening adhesion. Therefore, since the adhesive strength between the fired ceramic sheet and the circuit pattern is improved after firing, it is possible to prevent the circuit pattern from being peeled off from the ceramic sheet.

  According to the multilayer wiring board of claim 5, the circuit-forming charged powder comprising the first conductive metal powder and the second conductive metal powder having an average particle size smaller than that of the first conductive metal powder is used. In order to form a multilayer wiring board by printing a circuit pattern on a ceramic green sheet by electrophotography and then laminating those ceramic green sheets, the conductive metal powder in the circuit pattern constituting the multilayer wiring board after firing The packing of can be made dense.

  Therefore, since the sheet resistance and loss of the circuit pattern constituting the multilayer wiring board can be reduced, the multilayer wiring board constituted by this circuit pattern can be used in the high frequency region.

It is sectional drawing of the 1st reference example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 1st Example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 2nd Example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 2nd reference example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 3rd reference example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 4th reference example of the chargeable powder for circuit formation which concerns on this invention. It is sectional drawing of the 5th reference example of the chargeable powder for circuit formation which concerns on this invention. It is a block diagram of the electrophotographic system used when forming a circuit pattern on to-be-printed material. It is sectional drawing of one Example of the multilayer wiring board based on this invention. It is sectional drawing which shows the conventional chargeable powder for circuit formation.

Explanation of symbols

10 to 70 Chargeable powder for circuit formation 11 First conductive metal powder 12 Second conductive metal powder 13 Charge control agent 15 Hot melt resin 21 First chargeable powder 22 Second chargeable powder 23 First resin layer 33 Second resin layer 41 Third resin layer 51 Fourth resin layer 61 Fifth resin layer 71 Sixth resin layer 85 Printed material 90 Multilayer wiring boards 91a to 91c Ceramic green sheets 92a and 92b Circuit pattern

Claims (4)

A chargeable powder for forming a circuit used when a circuit pattern is printed on an object to be printed by electrophotography, the first conductive metal powder, and the heat melting formed around the first conductive metal powder A first resin layer made of a conductive resin, a first chargeable powder composed of a charge control agent fixed to the surface of the first resin layer, and a second conductive material having an average particle size smaller than that of the first conductive metal powder. Second chargeability comprising a conductive metal powder, a first resin layer made of a heat-meltable resin formed around the second conductive metal powder, and a charge control agent fixed to the surface of the first resin layer and powder, the Bei example,
The first chargeable powder and the second chargeable powder are adjusted to have substantially the same charging characteristics, and the first chargeable powder and the second chargeable powder are mixed at a desired ratio. A chargeable powder for forming a circuit. A chargeable powder for forming a circuit used when a circuit pattern is printed on a substrate by electrophotography, the first conductive metal powder, and the heat formed around the first conductive metal powder A first chargeable powder comprising a second resin layer comprising a meltable resin and a charge control agent; a second conductive metal powder having an average particle size smaller than that of the first conductive metal powder; and the second conductivity e Bei a second charged powder composed of the second resin layer comprising a heat-fusible resin formed around sexual metal powder and a charge control agent,
The first chargeable powder and the second chargeable powder are adjusted to have substantially the same charging characteristics, and the first chargeable powder and the second chargeable powder are mixed at a desired ratio. A chargeable powder for forming a circuit. The charged powder for circuit formation according to claim 1 or 2 , wherein the first charged powder and / or the second charged powder includes an adhesion reinforcing agent. Printed circuit pattern on a ceramic green sheet by an electrophotographic method, for circuit formation of claim 1 to claim 3, characterized in that formed by laminating the ceramic green sheet in which the circuit pattern is printed A multilayer wiring board using charged powder.