JPH04211189A - Circuit board and its manufacture - Google Patents

Abstract

PURPOSE:To provide a circuit board which has an insulating layer and shield layer having uniform thickness, does not cause any insufficient insulation, and is high in electromagnetic shielding effect and the manufacturing method of the circuit board. CONSTITUTION:This circuit board includes conductor 2 provided on a substrate 1, a first insulating film 4 coating the conductors 2, and a conductive film 3 coating the first insulating film 4. At least one of the films 4 and 3 is formed by an electrodeposition coating method.

Description

[Detailed description of the invention]

[00011

[Field of Industrial Application] The present invention relates to a circuit board and a method of manufacturing the same, and more particularly to a circuit board and a method of manufacturing the same used in optical equipment such as cameras, home appliances, computers, word processors, measuring instruments, and the like. [0002] Conventionally, the general method for manufacturing circuit boards is to form a copper foil circuit pattern on an insulating substrate by photolithography or screen printing using conductive paste, and then solder it. An insulating layer is provided by applying a resist or the like to the surface of the circuit, a conductive paste is then applied to the surface of the insulating layer to provide a shield layer, and an insulating layer is provided on the shield layer using a solder resist or the like. [0003] In addition to the above method of providing a shield layer, methods for shielding electromagnetic waves include a method of surrounding the circuit board with a sheet metal for shielding. Further, the insulating layer on the circuit pattern is also provided by laminating dry films. [0004]

[Problem to be Solved by the Invention] However, according to the conventional circuit board manufacturing method, the thickness of the insulating layer becomes thinner at the corners of the copper wires that make up the circuit, so the insulating layer is easily damaged at these parts. . Further, in the conventional circuit board manufacturing method, air bubbles or the like get mixed in between the copper wires, which tends to cause insulation breakdown or insulation failure, which has been a big problem. Furthermore, conventional circuit board manufacturing methods involve complicated processes and take a long time to manufacture, resulting in problems in terms of cost. [0005] Further, the conventional method of surrounding and shielding a circuit board with a sheet metal requires a large space for installing the sheet metal, and is not suitable for miniaturizing products. [0006] The present invention has been made in order to improve the drawbacks of the conventional technology, and the film thickness of the insulating layer and shield layer on the circuit pattern is uniform, there is no insulation defect, and the electromagnetic wave shielding effect is improved. The object of the present invention is to provide a high quality circuit board and a method for manufacturing the same. [0007]

[Means for Solving the Problems] A circuit board of the present invention includes a conductive wire provided on the substrate, a first insulating film covering the conductive wire, and a conductive film covering the first insulating film. have,
The present invention is characterized in that at least one of the first insulating film and the conductive film is formed by electrodeposition coating. [0008] Further, the method for manufacturing a circuit board of the present invention includes a first step of forming a circuit pattern made of conductive wires on the substrate, a second step of covering the circuit pattern with a first insulating film, a third step of coating the first insulating film with a conductive film, and in at least one of the second step and the third step, the substrate is immersed in an electrodeposition paint. The present invention is characterized in that an electrodeposition coating method is used in which the conductive wire is used as an electrode. [0009] The circuit board of the present invention is used in all electrical products such as optical equipment such as cameras, home appliances, word processors, computers, and measuring instruments. As shown in FIG. 1, in the circuit board of the present invention, a first insulating film 4 covers the periphery of a conductive wire 2 formed on an insulating substrate 1, and a conductive film covers the periphery of the first insulating film 4. 3 is what is covered. The conductive film 3 is a shield layer that shields electromagnetic waves. A circuit pattern is formed on the insulating substrate 1 by the conductive wire 2 . Preferably, the conductive wire 2 is made of copper. The periphery of the insulating film 4 is further covered with an insulating film 5 if necessary. The insulating film 5 is for preventing the circuit board of the present invention from coming into contact with other components and causing a short circuit when the circuit board of the present invention is installed in an electrical appliance.

In the circuit board of the present invention, each film 3.4. 5
At least one of the films is formed by electrodeposition coating. The film formed by electrodeposition coating is finally cured by irradiation with heat or light. [00111 Electrodeposition coating method is a method in which a pair of electrodes is placed in a solution containing a substance to form a coating (hereinafter referred to as electrodeposition paint) and the substance is deposited onto the electrode by applying a DC voltage. It is. Therefore, in the present invention, the conductive wire 2 formed on the substrate serves as one electrode. For example, a stainless steel plate may be used as the other electrode. [0012] Proposals have been made regarding electrodeposition coating methods. For example, JP-A-55-11175 proposes a method of applying two coats of electrodeposition paint. Furthermore, the present applicant has also proposed an electrodeposition paint containing ceramic powder and fluororesin powder in Japanese Patent Laid-Open No. 2-6564. [0013] The insulating substrate 1 includes the generally known
For example, an insulating substrate made of polycarbonate resin, polyetherimide resin, glass fiber-filled ABS resin, glass epoxy resin, etc. can be used. [0014] The circuit pattern using the conductive wire 2 can be formed by a generally known photolithography technique. That is, for example, copper foil is laminated on the insulating substrate 1,
Further, after coating a resist on the copper foil, a circuit pattern can be formed by exposing to light using a mask having a desired pattern, followed by development and etching. [0015] An insulating film 4 is formed around the conducting wire 2 by an electrodeposition coating method using an electrodepositable resin. [0016] Various researches have been made on resins used in electrodeposition coating methods. In order for the resin to be electrodeposited, it must be electrically charged when used as an electrodeposition paint. When a DC voltage is applied, the charged resin is drawn to the anode or cathode and deposits on the electrode to form a film. As the resin used in the present invention, resins conventionally used in electrodeposition coating methods can be used, such as acrylic/melamine, acrylic, epoxy, urethane, and alkyd resins. [0017] The resin used in the present invention may be an anionic resin or a cationic resin, but for practical purposes, a water-soluble resin or a water-dispersible resin having a carboxyl group is preferable. A resin prepolymer having a carboxyl group is dissolved or dispersed in water by being neutralized with ammonia or an organic amine. [0018] The resin concentration in the electrodeposition paint is preferably in the range of 5 to 20% by weight, preferably 7 to 15% by weight. [0019] The electrodeposition paint used in the present invention is preferably one in which a desired resin is dissolved or dispersed in water, but the electrodeposition paint may further contain an organic solvent such as an alcohol type or glycol ether type. I don't mind. A content of several percent of the organic solvent is sufficient. [00201 The insulating film 4 may contain ceramic powder. When the insulating film 4 contains ceramic powder, the insulating film 4 can be sufficiently cured at a low temperature, for example, about 90 to 100° C., when heat is applied to the insulating film 4 to cure it. As a result, a circuit board without thermal deformation can be obtained. [0021] When an electrodeposited film is formed using an electrodeposition paint containing ceramic powder, the reason why heat curing is performed at a low temperature is not clear, but the surface of the ceramic powder is quickly oxidized. This is thought to be because, unlike metal particles, the powder surface is maintained in a stable state while being activated to some extent, so the powder surface becomes a crosslinking point during curing and promotes the curing of the electrodeposited film. [0022] Examples of the ceramic powder contained in the insulating film 4 include aluminum oxide, titanium nitride, manganese nitride, tungsten nitride, tungsten carbide,
Lanthanum nitride, aluminum silicate, = molybdenum sulfide,
Examples include titanium oxide, graphite, and silicic acid compounds. [0023] If the particle size of the ceramic powder is too large, the insulating film 4 will be excessively hardened and become brittle. Moreover, if the particle size is too small, sufficient effects cannot be obtained. Therefore, the average particle size of the ceramic powder is 0.1 to 5 μm, particularly 0.1 to 5 μm.
5 to 2 μm is preferable. [0024] The amount of ceramic powder contained in the electrodeposition coating used for forming the insulating film 4 is determined to obtain a coating film 4 that has good physical properties such as adhesion and can be sufficiently cured even at low temperatures. For this reason, ceramic powder is added to 100 parts by weight of electrodepositable resin in an amount of 0.5 to 30 parts by weight and 2 to 3 parts by weight.
A dispersion of 25 parts by weight is preferred. The amount of eutectoid ceramic powder in the insulating film 4 is 10 to 30 wt%, especially 1
5 to 25 wt% is preferable. [0025] When electrodeposition coating is performed using an electrodeposition paint containing powder, the powder is deposited in the formed film because resin molecules are adsorbed around the powder particles in the electrodeposition paint. I'm doing it,
This seems to be because the powder also moves toward the electrode as the resin molecules are attracted to the electrode. [0026] After the insulating film 4 is formed, the conductive film 3 that will become a shield layer is formed around the insulating film 4. The conductive film 3 is formed by electrodeposition using an electrodeposition paint containing conductive powder. The conductive powder contained in the electrodeposition paint is as follows:
Ceramic powder whose surface is plated with metal (hereinafter referred to as metalized ceramic powder) or natural mica powder whose surface is plated with metal (hereinafter referred to as metalized natural mica powder) is preferable. Metallized ceramic powder or metalized natural mica powder is
Either one of them may be contained in the electrodeposition paint, or a mixture of both may be contained. When metallized ceramic powder or metallized natural mica is contained in the electrodeposition paint, as mentioned above, when the electrodeposition film is cured by heat treatment after the electrodeposition is completed, the heating temperature is 130 to 130℃.
It is preferable because it can be completely cured at a low temperature of 90°C to 100°C where 180°C is required. [0027] As for the metallized ceramic powder and the metallized natural mica powder used in the present invention, the surface of the ceramic powder or natural mica powder is coated with Cu, Ni, etc.
, Ag, Au, Sn, etc. are used. For plating the surfaces of these powders, Cu, Ag, and Ni can be suitably used from the viewpoint of shielding properties and cost. Electroless plating is suitable as a method for plating the powder surface. In addition, the plating thickness on the powder surface is 0.05 to 3 μm.
m, especially when it is 0.15 to 2 μm, it is possible to obtain excellent shielding properties and good coating film properties during low temperature curing. If the plating is formed thicker than 3 μm, the surface characteristics will be similar to those of metal particles, and the surface will be extremely active, so it will likely be oxidized in the air, resulting in insufficient hardening of the electrodeposited film at low temperatures. [0028] In forming N1 plating on powder, for example, as disclosed in JP-A-61-276979, an aqueous suspension of powder is prepared, and then this suspension is An electroless nickel plating aging solution is added to the powder to form nickel plating on the powder surface, resulting in a powder with a low phosphorus content, e.g.
% or less, it is possible to form an electrodeposited film with improved conductivity and shielding properties almost equivalent to that of Cu plating powder. [0029] As the ceramic powder used for the conductive powder, the same ceramic powder as that contained in the insulating film 4 can be used. Further, examples of natural mica include phlogobite mica, sericite mica, muscovite mica, and the like. [00301 The average particle size of the metallized ceramic powder or metallized natural mica is desirably in the range of 0.1 to 5 μm, preferably 0.5 to 2 μm. If it is less than 0.1 μm, the secondary agglomeration effect is large, and if it is less than 5 μm, If it exceeds it, it is undesirable due to sedimentation or cosmetic problems. [0031] As the conductive powder, in addition to metallized ceramic powder and metallized natural mica, resin powder whose surface is plated with metal (hereinafter referred to as metallized resin powder) and metal powder can also be used. [0032] As the resin powder used for the metallized resin powder, for example, fluororesin, polyethylene resin, acrylic resin, polystyrene resin, nylon, etc. can be used. As the metal plating applied to the surface of the resin powder, the same metal plating as in the case of the metallized ceramic powder can be used. The average particle size of the metallized resin powder is also the same as that of the metallized ceramic powder. [0033] As the metal powder, for example, Au, Pd, A
Examples include powders of g, Ni, Cu, Sn, Co, Mn, Fe, Te, and the like. The particle size of the metal powder is an average particle size of 0.01
~5μm, preferably 0.05~4μm, even 0.0
A range of 5 to 0.1 .mu.m is desirable; if it is less than 0.01 .mu.m, secondary agglomeration occurs, and if it exceeds 5 .mu.m, the powder will settle in the electrodeposition paint, which is undesirable. The metal powder is preferably manufactured using, for example, a thermal plasma evaporation method. [0034] In the present invention, the particle size of the conductive powder is
This is a value measured using a centrifugal sedimentation type particle size distribution analyzer. The measuring device actually used was 5ACP-3 (manufactured by Shimadzu Corporation). [0035] The content of conductive powder in the electrodeposition paint is
It is preferably in the range of 0.2 to 30 parts by weight, preferably 10 to 20 parts by weight, and more preferably 7 to 15 parts by weight, based on 100 parts by weight of the electrodepositable resin. [0036] The conductive powder in the conductive film 3 can be identified using an X-ray microanalyzer, and the amount of eutectoid of the conductive powder can be measured by thermogravimetric analysis. The eutectoid amount of conductive powder in coating film 3 is 5 to 50
wt%, especially 10-40wt%, even 15-35wt
% is preferred. [0037] For the conductive powder contained in the conductive film 3, only one of metallized ceramic powder, metallized natural mica powder, metalized resin powder, and metal powder may be used, for example. A mixture of two or more types, such as metallized ceramic powder and metal powder, may be used. Preferably, one or two types of conductive powder selected from metallized ceramic powder and metalized natural mica powder and one or two types of conductive powder selected from metalized resin powder and metal powder are used. It is best to use a mixture. This is because the metal powder and/or metallized resin powder fills the voids in the metallized ceramic powder and/or metallized natural mica powder in the conductive film 3, increasing the contact area between each powder. This is because the shielding properties are further improved, and the conductive film 3 can be hardened at a low temperature by the action of the metallized ceramic powder and/or the metallized natural mica powder. In this case, the mixing ratio of the conductive powder is 100 parts by weight of one or two types of conductive powder selected from metalized ceramic powder and metalized natural mica powder, and metalized resin powder and metal powder. It is preferable to use 20 to 300 parts by weight of one or more conductive powders selected from the following. [0038] By forming the conductive film 3 by an electrodeposition coating method, conductive powder is deposited in the conductive film 3 at a high density, and exhibits an excellent shielding function even if it is a thin film. [0039] After forming the conductive film 3, an insulating film 5 is further formed around the conductive film 3, if necessary. The insulating film 5 is the insulating film 4
The insulating film 4 is made of a material similar to that explained in the above.
It can be formed in the same manner as. Therefore, the insulating film 5 may or may not contain ceramic powder. The ceramic powder may be contained in both the insulating layer 4 and the insulating layer 5, or only in either one. Furthermore, neither the insulating layer 4 nor the insulating layer 5 need contain ceramic powder.

In this way, an insulating film 4. is formed around the conductive wire 2. After forming the conductive film 3 and, if necessary, the insulating film 5, the insulating film 4.5 and the conductive film 3 are cured by heat, light, or both heat and light. The energy for curing the resin may be either heat or light, but heat is preferable because it can be applied in a similar manner and easily. The temperature and heating time for curing the film are preferably 90 to 100°C for 20 to 180 minutes. Furthermore, an insulating film or a conductive film can be cured using energy other than heat and light.

The thickness of the insulating film 4 is 5 to 30 μm, more preferably 7 μm.
~25 μm is preferred. [0042] The thickness of the conductive film 3 is 7 to 40 μm, more preferably 1
0 to 25 μm is preferable. [0043] The thickness of the insulating film 5 provided as necessary is 10~
30 μm, more preferably 10 to 25 μm. [0044] When the insulating films 4, 5 and the conductive film 3 are formed by the electrodeposition coating method, the conductive wire on the substrate is used as an electrode and is immersed together with the other electrode in the electrodeposition paint. The temperature of the electrodeposition paint is preferably 20 to 25°C, and the water ion concentration is preferably pH 8 to 9. Further, the applied voltage is preferably a DC voltage of 50 to 170 cm, the current density is preferably 0.5 to 3 A/dm2, and the processing time is preferably 1 to 5 minutes. The type of resin used for the insulating films 4 and 5 and the conductive film 3 may be different for each film. [0045]

[Examples] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. [0046] Example 1 Using a 0.6 mm thick glass epoxy resin substrate laminated with 18 μm copper foil, a negative resist (manufactured by Tokyo Ohka Co., Ltd., OMR-83, viscosity 450C) was applied to the surface.
p) was applied with a spinner to form a 5 μm thick photosensitive material layer. Next, each pattern mask having a line width of 0.5 to 50 mm and a space of 1 to 20 mm was used for exposure and development. Next, using a copper etching solution (manufactured by Uezai Kogyo Co., Ltd., Alphain), etching was carried out by spraying to form a copper pattern circuit. [0047] Then, using an electrodeposition paint in which an acrylic/melamine resin (trade name: Honeybright CL-1; manufactured by Honey Kasei Co., Ltd.) was diluted to a concentration of 15 wt% using demineralized water,
Under conditions of pH 8.5 and bath temperature of 25° C., a 150 V DC voltage was applied for 3 minutes using the substrate as an anode and a stainless steel plate as a cathode to form an insulating film 4 with a thickness of 15 μm on the copper pattern circuit. did. [0048] Next, separately prepared acrylic/melamine resin (trade name Honeybright CL-1, manufactured by Honey Kasei Co., Ltd.)
100 parts by weight, average particle size 0. Powder 15 made of 0.2 μm thick nickel plating on 7 μm alumina
In an electrodeposition paint in which the weight part was dispersed and further diluted with demineralized water so that the mixture of resin and powder became 15 wt%, a thickness was applied around the insulating film 4 under the same conditions as those for forming the insulating film 4. Sa1
A conductive film 3 having a thickness of 7 μm was formed. [0049] Further, an insulating film 5 with a thickness of 15 μm was formed around the conductive film 3 under the same conditions as those for forming the insulating film 4 using the same electrodeposition paint as the insulating film 4. Finally, the substrate was washed with water. , then put the substrate in an oven at 97℃±1℃ for 150 minutes.
A circuit board of the present invention was obtained by heat treatment for a minute. [00501 The physical properties (adhesion, acid resistance, alkali resistance, combustibility), insulation resistance, and volume resistivity of the obtained circuit board were measured. The results are shown in Tables 1 to 3 below. [0051] The obtained insulating film and conductive film were dense and sufficiently adhered to adjacent films, and had satisfactory acid resistance, alkali resistance, and combustion resistance. [0052] In addition, the electromagnetic shielding effect of the circuit board can be measured using the transmission line method (
ASTM ES7.83). The results are shown in FIG. As shown in FIG. 2, the electromagnetic shielding effect was almost the same as that of electroless plating (see Reference Examples 1 and 2). [00531 Furthermore, this circuit board was cut as shown in FIG. 1, and the cross section of the circuit board was observed using a metallurgical microscope manufactured by Olympus Corporation (400x magnification). As a result, the insulating films 4 and 5 and the conductive film 3 were all formed to have a uniform thickness. [0054] Reference Example I Copper thin film with a film thickness of 0.7 μm and a film thickness of 0.4 μm on an ABS substrate
A metal plated member was obtained by sequentially laminating μm thick nickel thin films by electroless plating from the ABS substrate side. [0055] The electromagnetic shielding effect of this metal plated member was measured in the same manner as in Example 1. The results are shown in FIG. [0056] Reference Example 2 An ABS substrate was sprayed with nickel powder to form a nickel coating. [0057] The electromagnetic shielding effect of the member on which the nickel coating was formed was measured in the same manner as in Example 1. The results are shown in FIG. [0058] Comparative Example 1 Example 1 was placed on the same glass epoxy resin substrate as Example 1.
After forming a copper pattern circuit in the same manner as above, a solder resist (product name: FINEDEL) is applied using a conventional method.
DSR・2200(C), manufactured by Tamura Seisakusho), silver paste (product name LS-500, manufactured by Asahi Chemical Research Institute), solder resist (product name FINEDEL DSR・220)
0(C), manufactured by Tamura Seisakusho), 30 μm and 35 μm, respectively.
A circuit board was obtained by sequentially forming layers from the substrate side to a thickness of 30 μm. [0059] The physical properties, insulation resistance, and volume resistivity of the obtained circuit board were measured in the same manner as in Example 1. The results are shown in Tables 1-3. [00601

[Table 1] Table ■ [0061] (Note) The test method in the above table is as follows. (1) Adhesion... JIS DO202 (2) Acid resistance - Immersion treatment in 10Vo1% H2S 04 at room temperature for 20 minutes (3) Alkali resistance... 5 wt% NaOH at room temperature 30 minutes
Separate immersion treatment (4) Flammability...UL94 test method [0062]

[Table 2] Table [0063] (Note) The insulation resistance in the above table is JIS
Based on Z3197, the comb-shaped electrode G-10 and the substrate moisture absorption treatment show a 1 minute value at 55° C., 98% RH, and DC 500V. The resistance value was measured using a super wire resistance measuring device HP43 made by YHP.
)・29A was used. [0064]

[Table 3] Table [0065] (Note) The specific resistance values in the above table are JIS
This is a value measured using C6481. [0066] Example 2 A circuit board of the present invention was produced in the same manner as in Example 1, except that 15 parts by weight of the nickel-plated alumina powder used in Example 1 was replaced with 10 parts by weight of copper-plated alumina powder. Created. The plating thickness of the copper-plated alumina powder was 0.2 μm. Further, the average particle diameter of the alumina powder was 1.2 μm. [0067] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding effect were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0068] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film was formed to have a uniform thickness. [0069] Example 3 A copper pattern circuit and an insulating film 4 were formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [00701 Next, separately prepared acrylic/melamine resin (trade name Honeybright CL-1, manufactured by Honey Kasei Co., Ltd.)
To 100 parts by weight, 7 parts by weight of powder made of copper plating applied to alumina with an average particle size of 1.0 μm to a thickness of 0.2 μm was dispersed, and the mixture of resin and powder was further reduced to 15 wt% with demineralized water. A conductive film 3 having a thickness of 17 μm was formed around the insulating film 4 under the same conditions as those for forming the insulating film 4 in an electrodeposition paint diluted as follows. [00711 Finally, the substrate was washed with water, and then heated to 97°C±
The substrate was placed in an oven at 1° C. and heat-treated for 150 minutes to obtain a circuit board of the present invention. [0072] Physical properties of this circuit board (adhesion, acid resistance,
The alkali resistance, combustibility) and electromagnetic shielding effect were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0073] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0074] Example 4 A copper pattern circuit was formed on a 0.8 mm thick glass epoxy resin substrate in the same manner as in Example 1. [0075] After that, alkyd resin (trade name TF 121, manufactured by Shinto Toyo Co., Ltd.) was added to a concentration of 1 using demineralized water.
Using an electrodeposition paint diluted to 5 tw%, under conditions of pH 8.5 and bath temperature of 25°C, a DC voltage of 150 V was applied for 3 minutes using the substrate as an anode and a stainless steel plate as a cathode.
A μm thick insulating film 4 was formed on the copper pattern circuit. [0076]Next, 100 parts by weight of a separately prepared alkyd resin (trade name TF 121, manufactured by Shinto Paint Co., Ltd.) was coated with 0.0% nickel plating on alumina having an average particle size of 1.0 μm. 7 parts by weight of the powder applied to a thickness of 1 μm was dispersed in an electrodeposition paint that was further diluted with demineralized water so that the mixture of resin and powder was 15 wt%, under the same conditions as those for forming the insulating film 4. Below, a conductive film 3 with a thickness of 17 μm is placed around the insulating film 4.
was formed. [0077] Further, an insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 using the same electrodeposition paint as the insulating film 4 and under the same conditions as those for forming the insulating film 4. [0078] Finally, the substrate is washed with water, and then heated to 97°C ± 1
The circuit board of the present invention was obtained by placing the board in an oven at .degree. C. and heating it for 150 minutes. [0079] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [00801 Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film was formed to have a uniform thickness. [0081] Example 5 A copper pattern circuit and an insulating film 4 were formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [0082] Next, separately prepared acrylic/melamine resin (trade name Honeybright CL-1, manufactured by Honey Kasei Co., Ltd.)
100 parts by weight of copper powder with an average particle size of 0.03 μm
Disperse the weight parts and further add demineralized water to make a mixture of resin and powder.
Insulating film 4 in an electrodeposition paint diluted to 5 wt%.
A thickness of 17 mm was formed around the insulating film 4 under the same conditions as the formation conditions of
A conductive film 3 having a thickness of μm was formed. [0083] Furthermore, an insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 using the same electrodeposition paint as the insulating film 4 and under the same conditions as those for forming the insulating film 4. [0084] Finally, the substrate is washed with water, and then heated to 97°C±
The substrate was placed in an oven at 1° C. and heat-treated for 150 minutes to obtain a circuit board of the present invention. [0085] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0086] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film was formed to have a uniform thickness. [0087] Example 6 A copper pattern circuit and an insulating film 4 were formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [0088] Next, separately prepared acrylic/melamine resin (trade name Honeybright CL-1, manufactured by Honey Kasei Co., Ltd.)
100 parts by weight of copper powder with an average particle size of 0.02 μm
Disperse the weight parts and further add demineralized water to make a mixture of resin and powder.
Insulating film 4 in an electrodeposition paint diluted to 5 wt%.
A thickness of 15 mm was formed around the insulating film 4 under the same conditions as the formation conditions of
A conductive film 3 having a thickness of μm was formed. [0089] Finally, the substrate is washed with water, and then heated to 97°C±
The substrate was placed in an oven at 1° C. and heat-treated for 150 minutes to obtain a circuit board of the present invention. [00901 The physical properties (adhesion, acid resistance, alkali resistance, combustibility) and electromagnetic shielding effect of this circuit board were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0091] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0092] Example 7 A copper pattern circuit and an insulating film 4 were formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [0093] After that, alkyd resin (trade name TF 121, manufactured by Shinto Toyo Co., Ltd.) was added to a concentration of 1 using demineralized water.
Using an electrodeposition paint diluted to 5 tw%, under conditions of pH 8.5 and bath temperature of 25°C, a DC voltage of 150 V was applied for 3 minutes using the substrate as an anode and a stainless steel plate as a cathode.
A μm thick insulating film 4 was formed on the copper pattern circuit. [00941]Next, 15 parts by weight of nickel powder with an average particle size of 0.03 μm was dispersed in 100 parts by weight of an alkyd resin (trade name TF 121, manufactured by Shinto Paint Co., Ltd.) prepared separately, and further desorbed. 15wt of resin and powder mixture in salt water
A conductive film 3 having a thickness of 20 μm was formed around the insulating film 4 under the same conditions as those for forming the insulating film 4 in an electrodeposition paint diluted to a concentration of 20 μm. [0095] Further, an insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 using the same electrodeposition paint as the insulating film 4 and under the same conditions as those for forming the insulating film 4. [0096] Finally, the substrate was washed with water, and then heated to 97°C ± 1
The circuit board of the present invention was obtained by placing the board in an oven at .degree. C. and heating it for 150 minutes. [0097] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0098] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0099] Example 8 The 15 parts by weight of the nickel-plated alumina powder used in Example 1 was replaced with 7 parts by weight of the nickel-plated alumina powder and 5 parts by weight of the copper powder.
A circuit board of the present invention was produced in the same manner as in Example 1, except that the weight part of the mixture was changed. The plating thickness of nickel-plated alumina powder is 0. It was 2 μm. The average particle diameter of the alumina powder was 1.2 μm. The average particle diameter of the copper powder was 0.03 μm. [01001 The physical properties (adhesion, acid resistance, alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding of this circuit board were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [01011 Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film was formed to have a uniform thickness. [0102] Example 9 The same procedure as Example 6 was carried out except that 10 parts by weight of the copper powder used in Example 6 was replaced with a mixture of 5 parts by weight of nickel-plated alumina powder and 10 parts by weight of copper powder. A circuit board of the present invention was created. The plating thickness of the nickel-plated alumina powder was 0.2 μm. The average particle size of alumina powder is 1
．． It was 0 μm. The average particle size of copper powder is 0.02 μm
Met. [0103] Physical properties of this circuit board (adhesion, acid resistance,
The alkali resistance, combustibility) and electromagnetic shielding effect were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0104] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0105] Example 10 Same as Example 4 except that 7 parts by weight of nickel-plated alumina powder used in Example 4 was replaced with a mixture of 7 parts by weight of copper-plated alumina powder and 5 parts by weight of nickel powder. A circuit board according to the present invention was prepared. The plating thickness of the copper-plated alumina powder was 0.2 μm. The average particle diameter of the alumina powder was 1.0 μm. The average particle size of the nickel powder was 0.03 μm. [0106] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility), insulation resistance, volume resistivity, and electromagnetic shielding were measured in the same manner as in Example 1. As a result, good effects similar to those of Example 1 were obtained. [0107] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0108] Example 11 A copper pattern circuit was formed on a 0.6 mm thick glass epoxy resin substrate in the same manner as in Example 1. [0109] After that, aluminum nitride with an average particle size of 1.5 μm was dispersed in an acrylic/melamine resin (trade name: Honeyflight CL-1, manufactured by Honey Kasei Co., Ltd.) at 3% by weight of the resin, and then mixed with demineralized water. 15% by weight mixture of resin and powder
Using an electrodeposition paint diluted to give a pH of 8.5,
At a bath temperature of 25° C., a DC voltage of 150 μm was applied for 3 minutes using the substrate as an anode and a stainless steel plate as a cathode to form an insulating film 4 with a thickness of 15 μm and a powder eutectoid content of 25% by weight. Formed on top of a copper pattern circuit. [01101 Next, separately prepared acrylic melamine resin (trade name Honeybrite CL-1, manufactured by Honey Kasei Co., Ltd.) 1
Disperse 10 parts by weight of powder made of alumina with an average particle size of 1.0 μm and nickel plating to a thickness of 0.1 μm in 0.00 parts by weight, and further add 15 w of the resin and powder mixture with demineralized water.
In an electrodeposition paint diluted to 100% by weight, a thickness of 17 μm was applied around the insulating film 4 under the same conditions as those for forming the insulating film 4.
A conductive film 3 having a powder eutectoid content of 30% by weight was formed. [01111] Further, an insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 using the same electrodeposition paint as the insulating film 4 and under the same conditions as those for forming the insulating film 4. [0112] Finally, the substrate was washed with water, and then heated to 97°C ± 1
The circuit board of the present invention was obtained by placing the board in an oven at .degree. C. and heating it for 150 minutes. [0113] Physical properties of the obtained circuit board (adhesion, acid resistance, alkali resistance, combustibility), insulation resistance, volume resistivity,
Hardness (pencil) and scratch resistance (eraser) were measured. The results are shown in Tables 4 to 6 below. (0114) The obtained insulating film and conductive film are dense and adhere well to adjacent films, and have acid resistance, alkali resistance,
The flame resistance, hardness and scratch resistance were also satisfactory. [0115] In addition, the transmission line method (
ASTM ES7.83). As a result, the electromagnetic shielding effect was as good as in Example 1. [01161 Furthermore, when the cross section of the substrate was observed in the same manner as in Example 1, it was found that each film had a uniform thickness. [0117]

[Table 4] Table [0118] (Note) The test method in the above table is as follows. [0119] (1) Adhesion... JIS DO202 (2) Acid resistance - Immersion treatment in 10 Vol% H2S 04 at room temperature for 20 minutes (3) Alkali resistance... 5 wt% NaOH at room temperature, 3
0 minute immersion treatment (4) Flame resistance...UL94 test method (5) Hardness...JIS K5400 (6) Scratch resistance
・・Number of times required to expose the underlying layer when the insulating coating is rubbed with an eraser [01201

[Table 5] Table (01211 (Note) The insulation resistance in the above table is JIS Z
3197 is compliant, and the comb-shaped electrode G-10 and the substrate moisture absorption treatment show a 1 minute value at 55° C., 98% RH, and DC 500V. The resistance value was measured using a super insulation resistance measuring device HP43 manufactured by YHP.
29A was used. [0122] [Table 6] Table [0123] (Note) The specific resistance values in the above table are based on JIS
This is a value measured using C6481. [0124] Example 12 Example 1 was prepared on a 0.6 mm thick glass epoxy resin substrate.
A copper pattern circuit was formed in the same manner as above. [0125] Thereafter, 3% by weight of the aluminum nitride powder used for the insulating film 4 of Example 11 was mixed with an average particle size of 1.0 μm.
The insulating film 4 was formed in the same manner as in Example 11 except that the alumina powder was changed to 5% by weight. [0126] Next, separately prepared acrylic melamine resin (trade name Honeybright CL-1, manufactured by Honey Kasei Co., Ltd.) 1
0.00 parts by weight of nickel plating on alumina with an average particle size of 1.0 μm. Disperse 15 parts by weight of the powder applied to a thickness of 3 μm, and further add 15 parts by weight of the resin and powder mixture with demineralized water.
In an electrodeposition paint diluted to %wt, a thickness of 15 μm was applied around the insulating film 4 under the same conditions as those for forming the insulating film 4.
A conductive film 3 having a powder eutectoid content of 27% by weight was formed. [0127] Furthermore, using the same electrodeposition paint as the insulating film 4,
An insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 under the same conditions as those for forming the insulating film 4. [0128] Finally, the substrate was washed with water, and then heated to 97°C ± 1
The circuit board of the present invention was obtained by placing the board in an oven at .degree. C. and heating it for 150 minutes. [0129] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, flammability, hardness and scratch resistance), insulation resistance,
Volume resistivity and electromagnetic shielding were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [01301 Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film had a uniform thickness. [0131] Example 13 A copper pattern circuit was formed on a 0.6 mm thick glass epoxy resin substrate in the same manner as in Example 1. [0132] After that, alkyd resin (trade name TFI
21. After dispersing silicon carbide with an average particle size of 2.0 μm at 1% by weight of the resin in Shinto Toyo Co., Ltd.), the mixture of resin and powder was adjusted to 15% by weight with demineralized water. Using diluted electrodeposition paint, under conditions of pH 8.5 and bath temperature 25°C,
Using the substrate as an anode and a stainless steel plate as a cathode, 15
A DC voltage of 0 cm was applied for 3 minutes to form an insulating film 4 having a thickness of 15 μm and a powder eutectoid content of 25% by weight on the copper pattern circuit. [01331] Next, 100 parts by weight of an alkyd resin (trade name TF 121, manufactured by Shinto Paint Co., Ltd.) prepared separately was coated with copper plating on alumina with an average particle size of 1.0 μm.
．． 10 parts by weight of the powder applied to a thickness of 2 μm was dispersed in an electrodeposition paint that was further diluted with demineralized water so that the mixture of resin and powder was 15 wt% under the same conditions as those for forming the insulating film 4. Below, the thickness is 17 μm around the insulating film 4, and the eutectoid amount of powder is 3.
A conductive film 3 containing 0% by weight was formed. [0134] Further, an insulating film 5 having a thickness of 15 μm was formed around the conductive film 3 using the same electrodeposition paint as the insulating film 4 and under the same conditions as those for forming the insulating film 4. [0135] Finally, the substrate was washed with water, and then heated to 97°C ± 1
The circuit board of the present invention was obtained by placing the board in an oven at .degree. C. and heating it for 150 minutes. [0136] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, flammability, hardness and scratch resistance), insulation resistance,
Volume resistivity and electromagnetic shielding were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [0137] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film had a uniform thickness. [0138] Example 14 A copper pattern circuit was formed on a 0.6 mm thick glass epoxy resin substrate in the same manner as in Example 1. [0139] Thereafter, 3% by weight of the aluminum nitride powder used for the insulating film 4 of Example 11 was mixed with an average particle size of 5.0 μm.
Example 1 except that the alumina powder was changed to 1.5% military
An insulating film 4 was formed in the same manner as in Example 1. [01401 Next, the same conductive film 5 as in Example 11 was formed in the same manner as in Example 11. [01411Finally, the substrate was washed with water and then heated to 97℃±
The substrate was placed in an oven at 1° C. and heat-treated for 150 minutes to obtain a circuit board of the present invention. [0142] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, combustibility, hardness, and scratch resistance) and electromagnetic shielding effect were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [0143] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film was formed to have a uniform thickness. [0144] Example 15 A copper pattern circuit and an insulating film 4 were formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [0145] Thereafter, the same conductive film 3 as in Example 5 was formed in the same manner as in Example 5. [0146] Further, an insulating film 5 similar to that in Example 11 was formed in the same manner as in Example 11, and finally the film was cured in the same manner as in Example 11 to produce a circuit board of the present invention. [0147] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, flammability, hardness and scratch resistance), insulation resistance,
Volume resistivity and electromagnetic shielding were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [0148] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film had a uniform thickness. [0149] Example 16 10 parts by weight of the nickel-plated alumina powder used in the conductive film 3 of Example 12 was mixed with silver powder 5 with an average particle diameter of 0.02 μm.
A circuit board of the present invention was produced in the same manner as in Example 12, except that the parts by weight were changed. [0150] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, flammability, hardness and scratch resistance), insulation resistance,
Volume resistivity and electromagnetic shielding were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [01511 Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film was formed to have a uniform thickness. [0152] Example 17 A copper pattern circuit was formed in the same manner as in Example 1 on a 0.6 mm thick glass epoxy resin substrate. [0153] After that, insulating film 4. Conductive film 3 and insulating film 5
and Example 11., respectively. A circuit board of the present invention was produced in the same manner as in Example 8 and Example 11. [0154] Physical properties of this circuit board (adhesion, acid resistance,
Alkali resistance, flammability, hardness and scratch resistance), insulation resistance,
Volume resistivity and electromagnetic shielding were measured in the same manner as in Example 11. As a result, good effects similar to those of Example 11 were obtained. [0155] Furthermore, when the cross section of the substrate was observed in the same manner as in Example 11, it was found that each film had a uniform thickness. [0156]

As described above, according to the present invention, the insulating film and conductive film of a circuit board can be made into thin films with a dense and uniform thickness. Further, a circuit board having no insulation defects and excellent electromagnetic shielding effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a circuit board according to the present invention.

FIG. 2 is an example of a graph showing the shielding effect of the circuit board according to the present invention.

[Explanation of symbols] 1 Board 2 Conductor wire 3 Conductive film 4 Insulating film 5 Insulating film

[Figure 1]

[Figure 2]

Claims (2)

[Claims] 1. A conductive wire provided on a substrate, a first insulating film that covers the conductive wire, and a conductive film that covers the first insulating film, the first insulating film and the A circuit board characterized in that at least one of the conductive films is formed by an electrodeposition coating method. 2. A first step of forming a circuit pattern made of conductive wires on a substrate, a second step of coating the circuit pattern with a first insulating film, and a second step of coating the first insulating film with a conductive film. and a third step of coating, and in at least one of the second step and the third step, the substrate is immersed in an electrodeposition paint and the conductive wire is used as an electrode for electrodeposition coating. A method for manufacturing a circuit board, characterized by using a method.