JP2002059430A - Method for manufacturing anisotropic conductive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for manufacturing anisotropic conductive sheet, capable of being manufactured in an extremely easy and certain manner, even if the arrangement of ferromagnetic parts and non-magnetic parts is a complicated and fine pattern, and good in durability even with respect to repeated use and capable of efficiently manufacturing the anisotropic conductive sheet wherein the arrangement of conductive parts and insulating parts has a complicated pattern and the center-to-center distance between the adjacent conductive parts is small. SOLUTION: The mold for manufacturing the anisotropic conductive sheet is constituted by alternately arranging magnetic parts and non-magnetic parts on the surface of a substrate comprising a magnetic metal and each of the non-magnetic parts consists of a non-magnetic metal layer and a heat-resistant polymeric substance layer and each of the magnetic parts consists of magnetic metal columnar elements and a magnetic metal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of inspecting the electrical performance of a printed circuit board or the like, for example, to achieve an electrical connection between the circuit board to be inspected and an electrical inspection apparatus. The present invention relates to a metal mold for producing an anisotropic conductive sheet used in (1).

[0002]

2. Description of the Related Art Anisotropically conductive sheets are useful in various applications as members for achieving electrical connection because of their characteristics. For example, anisotropic conductive sheets such as printed circuit boards having fine pattern electrodes are useful. It is suitable as a connector for electrical inspection.

An anisotropic conductive sheet is one in which conductive portions extending in the thickness direction of the sheet are arranged in a state in which the conductive portions are insulated by an insulating portion. Conventionally, various structures are known. . For example, as a pressurized anisotropic conductive sheet, a sheet in which conductive particles are relatively densely dispersed in a conductive portion is known.

As a method for producing an anisotropic conductive sheet having the above structure, a layer of a molding material comprising a mixture of conductive particles having magnetic properties and a polymer material is formed in a molding space of a mold. A method is known in which a magnetic field is applied to the layer of the molding material in the thickness direction of the layer using the mold as a magnetic pole, the conductive particles are moved by the action of the magnetic force, and the particles are cured in that state. It is also known to form a portion where conductive particles are oriented (conductive portion) and a non-conductive portion where conductive particles are scarcely present, if necessary.

A typical mold used in the above-described method of manufacturing an anisotropic conductive sheet is a set of two upper and lower dies each having a substantially flat plate shape and corresponding to each other. The upper mold and the lower mold are configured to be attachable to the electromagnet, or are configured integrally with the electromagnet, and heat-curing the molding material layer while applying a magnetic field to the molding material layer It is of a structure that can be done. Also, in order to form a conductive portion at an appropriate position by applying a magnetic field to the layer of the molding material, at least one of the upper mold and the lower mold of the mold is placed on a substrate made of a ferromagnetic material such as iron or nickel. A layer in which a ferromagnetic portion made of iron, nickel, or the like for generating an intensity distribution in a magnetic field in a mold, and a nonmagnetic material portion made of a radiation-curable resin are arranged in a mosaic pattern (hereinafter referred to as a “mosaic layer”). "), And the molding surfaces of the upper and lower molds of the mold are flat or have slight irregularities.

In these molds, a magnetic field can be formed on the entire molding surface on which the layer of the molding material is formed by an electromagnet, and a magnetic field having an intensity distribution can be formed as required. The arrangement, shape, and the like of the ferromagnetic portion and the nonmagnetic portion in the mosaic layer of the mold are determined based on the arrangement pattern of the conductive portions of the anisotropic conductive sheet to be manufactured. That is, the ferromagnetic portion is disposed at a position corresponding to the conductive portion of the anisotropic conductive sheet, and the cross-sectional shape of the conductive portion is formed based on the shape of the ferromagnetic portion.

The mold having the mosaic layer as described above is
For example, it can be manufactured by forming a non-magnetic material portion on a ferromagnetic material plate by a photolithography method, and then forming the ferromagnetic material portion by, for example, plating.

[0008]

However, in the manufacture of the above-described mold, for example, when a mold having a radiation-cured resin layer formed on the entire non-magnetic material portion is used, the anisotropic process is performed several tens of times or more. There is a problem in durability against repeated use of the conductive sheet. For this reason, a non-magnetic material part which is excellent in durability and is replaced with a radiation-curable resin layer is required. Further, in the manufacture of the mold as described above, in the step of forming a magnetic metal column on the magnetic material portion, on one metal substrate, the height is uniform, the tip is flat, and the aspect ratio is large. It has been considered difficult to form a large number of fine magnetic pillars.

For the reasons described above, a mold having a mosaic layer in which the arrangement of the ferromagnetic material portion and the nonmagnetic material portion is complicated and miniaturized, that is, the arrangement of the conductive portions is complicated and the center of the adjacent conductive portion is It has been difficult to manufacture an anisotropic conductive sheet having a pattern with a small distance, and to easily and inexpensively manufacture a mold having good durability. Therefore, an object of the present invention is to form a microscopic mosaic layer in which the arrangement of the ferromagnetic material portion and the non-magnetic material portion is complicated and easy to form, to produce a desired anisotropic conductive sheet, and to provide a durable An object of the present invention is to provide a good mold easily and inexpensively.

[0010]

According to the present invention, a magnetic material portion and a non-magnetic material portion are alternately arranged on a surface of a substrate made of a magnetic metal, and the non-magnetic material portion is formed of a non-magnetic metal layer. And a heat-resistant polymer material layer, wherein the magnetic part is made of a magnetic metal column and a magnetic metal powder. .

[0011]

In the mold of the present invention, a ferromagnetic portion is disposed at a position corresponding to a conductive portion of an anisotropic conductive sheet to be formed. The ferromagnetic material portion is composed of a magnetic metal columnar portion and a magnetic metal powder portion, and it is preferable that they are laminated. The ferromagnetic metal column can be formed by, for example, photolithography and plating. Separately, a nonmagnetic metal sheet and a thermosetting heat-resistant resin sheet were used, a portion corresponding to the ferromagnetic material portion in the thermosetting heat-resistant resin sheet was removed, and the portion was filled with metal powder. The sheet composed of the non-magnetic metal sheet and the thermosetting heat-resistant resin sheet thus obtained is aligned so that the ferromagnetic metal column portion and the ferromagnetic powder portion match. It can be manufactured by laminating. By using such a mold, a mosaic made of a ferromagnetic layer having a large aspect ratio can be extremely easily and reliably formed even if the pattern of the ferromagnetic material portion and the nonmagnetic material portion is complicated and fine. A layer can be formed, and a mold for manufacturing an anisotropic conductive sheet having good durability against repeated use can be manufactured. The surface of the mold having the mosaic layer must have a flat surface with no defect at the tip of the ferromagnetic material, and may be flush with the tip of the ferromagnetic material except for the tip of the ferromagnetic material, and may have a slight step. It may be a planar shape with a shape. For example, the magnetic material portion and the non-magnetic material portion may have different heights.

Next, the mold of the present invention will be specifically described. FIG. 9 is an explanatory view showing a specific configuration of an example of the mold for producing an anisotropic conductive sheet of the present invention. In FIG. 9, reference numeral 1 denotes a substrate made of a magnetic metal, on which a non-magnetic portion 2 and a ferromagnetic portion 3 and 3 'forming a mosaic layer are provided. On the first non-magnetic portion 2, there is a second non-magnetic layer 1a having a thickness smaller than that of the ferromagnetic portion 3. The first nonmagnetic layer 2 is preferably made of a polymer material cured by heat. The second nonmagnetic layer 1a is preferably made of a metal layer. The non-magnetic material portion is preferably a laminate of both the non-magnetic metal layer 1a and the heat-resistant polymer material layer 2. Particularly, the non-magnetic metal layer 1a is positioned outside (molding surface side) so that the heat resistance is high. It is preferable to form the laminate with the molecular substance layer 2 on the inside in that the leaching from the polymer substance can be prevented and the surface of the mosaic layer can be flattened.

The mold having the above configuration is manufactured by, for example, the following method. (1) Formation of resist layer 2a As shown in FIG. 1, a resist layer is formed on a substrate 1c composed of a nonmagnetic metal 1a and a releasable support layer 1b while leaving a portion where a ferromagnetic portion is to be formed. 2a is formed.
As a method for forming the resist layer 2a, for example, a photolithography technique can be used. In this case, a photoresist described later is coated on the substrate 1a by lamination, screen printing, spin coating, applicator coating, or the like.
The resist layer 2a can be formed by irradiating a pattern corresponding to the ferromagnetic portion 3 as shown in FIG. 1 with a film mask 6 having a radiation shielding portion 5 and then irradiating the radiation, followed by development.

As the substrate 1c, for example, a substrate obtained by depositing an electrolytic copper foil on a copper peelable support layer, a substrate obtained by depositing an electrolytic copper foil on a stainless steel peelable support layer, or the like can be used. , Copper thin plate, aluminum thin iron, and zinc thin plate can be used alone. These preferably have a thickness of 1 to 300 μm, preferably have a smooth surface, and have been chemically degreased and roughened. The resist layer 2a is made of a polymer substance cured by radiation, and examples of the material include an acrylic dry film resist, an epoxy liquid resist,
A photoresist such as a polyimide-based liquid resist may be used. The thickness of the nonmagnetic layer 2a is preferably 10 μm or more, more preferably 20 to 300 μm.
It is.

(2) Formation of Ferromagnetic Portion As shown in FIG. 2, a ferromagnetic portion 3 is formed on a portion of the substrate 1c where the nonmagnetic layer 2a is not formed. As a method for forming the ferromagnetic portion 3, for example, an electrolytic plating method can be used. After the ferromagnetic portion 3 is formed, the surface of the ferromagnetic portion 3 is polished, whereby the surface can be made flat as shown in FIG.

The ferromagnetic material portion 3 is made of, for example, a ferromagnetic metal such as iron, iron-nickel alloy, iron-cobalt alloy, nickel, and cobalt. The thickness of the ferromagnetic portion 3 is preferably 10 μm or more, more preferably 20 to 300 μm. The thickness of the ferromagnetic part 3 is 1
When the thickness is less than 0 μm, it is difficult to apply a magnetic field having a sufficient intensity distribution when manufacturing the anisotropic conductive sheet. As a result, in a process shown in FIG. Since it becomes difficult to aggregate the conductive particles in the molding material at a high density in the portion sandwiched between the ferromagnetic portions 3, that is, in the portion where the conductive portion is to be formed,
The resulting sheet is unlikely to have good anisotropic conductivity.

(3) Formation of Second Non-Magnetic Layer 1a From the state shown in FIG. 3, the resist layer 2a was removed to obtain the shape shown in FIG. 4 to form a second non-magnetic layer. . (4) Formation of First Non-Magnetic Material Layer 2 Next, as shown in FIG. 5, a heat-resistant polymer resin sheet 2C was laminated on the substrate 1 to form the first non-magnetic material layer 2. . Then, a hole 3HC was formed in a portion corresponding to the ferromagnetic portion 3 of the heat-resistant polymer resin sheet 2C by a numerically controlled laser drilling machine. Then, as shown in FIG. 6, the ferromagnetic metal particles 3 'were filled in the holes 3HC of the 2C. Examples of the ferromagnetic metal particles 3 ′ include simple ferromagnetic metal particles such as iron, nickel, and cobalt, and alloy ferromagnetic metal particles composed of two or more of these metal elements. Of these, simple ferromagnetic metal particles such as iron and cobalt are preferable from the viewpoint of magnetic properties, and iron particles are particularly preferable. (5) Molding The first non-magnetic layer and the second non-magnetic layer manufactured as described above are combined with each other so that the ferromagnetic portions 3 and 3 'correspond to each other.
They were arranged as shown in FIG. Next, after these were laminated by thermocompression bonding, the peelable support layer 1b was peeled off and removed. As a result, as shown in FIG. 9, a non-magnetic portion composed of the first non-magnetic layer 2 and the second non-magnetic layer 1a, a ferromagnetic portion 3, and a ferromagnetic portion 3 ' A mold composed of a mosaic layer with the ferromagnetic material portion composed of is formed.

As a material for forming the first nonmagnetic layer 2, various thermosetting resin sheets, various adhesives, and the like are used. The thermosetting resin is preferably made of a heat-resistant resin having high dimensional stability, and various resins can be used. Preferred specific examples include glass fiber reinforced epoxy prepreg resin, polyimide prepreg resin, epoxy prepreg resin, and the like. Among them, epoxy prepreg resin is most suitable. In order to combine these into a mold, the first non-magnetic material may be applied on the substrate 1, but it is preferable to use it as a resin sheet. The thickness of the non-magnetic layer 2 is designed based on the thickness of the ferromagnetic portions 3 and 3 ', but is usually at least one time the thickness of the ferromagnetic portion 3, preferably 1.01 to 1.0.
It is 5 times, more preferably 1.02 to 3 times.
The thickness of the ferromagnetic portion 3 is designed so as not to exceed 10 μm to 500 μm, more preferably to 20 μm to 200 μm. A non-magnetic metal is used as a material forming the second non-magnetic layer 1a, but various non-magnetic metals can be used as long as the connection between the layers is maintained. Specific examples thereof include diamagnetic substances such as copper, zinc, and tin, and aluminum. The thickness of the nonmagnetic layer 1a is designed based on the anisotropic conductive sheet to be manufactured, but is usually not more than 1 time, preferably not more than 0.8 times the thickness of the ferromagnetic material portion 3. is there. Specifically, more preferably, 1 μm
m to 300 μm, more preferably 3 μm to 200 μm
The thickness is designed so as not to exceed the thickness of the ferromagnetic portion 3 within the range described below.

According to the above-described method, even if the arrangement of the non-magnetic portion 2 and the ferromagnetic portion 3 is a complicated and fine pattern, the film mask 6 having a pattern corresponding to this arrangement can be obtained. The mosaic layer can be easily formed by manufacturing and drilling the thermosetting resin sheet 2C constituting the non-magnetic material layer 2 and the portion corresponding to the ferromagnetic material portion of the thermosetting resin sheet 2C. Is possible. According to this method, since the ferromagnetic material plating is formed in the opening corresponding to the ferromagnetic material portion resolved by photolithography, a mosaic layer having a pattern with high fidelity to the film mask 6 can be formed. .
Furthermore, by forming the non-magnetic material portion with a laminate of a heat-resistant resin layer and a non-magnetic metal thin layer, it is possible to manufacture a mold having higher repetition durability. Also,
On the surface of the nonmagnetic layer 1a, a resin layer, for example, a thermosetting resin layer or a radiation curable resin layer, or a metal layer, for example, a nonmagnetic metal layer such as copper is formed by plating or sputtering. By forming the concave portion by forming the nonmagnetic layer 1a by chemical etching, an anisotropic conductive sheet having an uneven surface can be manufactured.

In the mold of the present invention, conductive portions are formed by chaining conductive particles in an insulator in the thickness direction, and portions other than the conductive portions are formed of an elastic insulator. It is suitable for manufacturing sheets. As the insulator, an insulator having elasticity is preferable. As such an insulator having elasticity, a rubber-like polymer is preferable. Rubbery polymers include polybutadiene, natural rubber, polyisoprene, SB
Conjugated diene rubbers such as R and NBR and hydrogenated products thereof, styrene butadiene diene block copolymer,
Block copolymers such as styrene isoprene block copolymers and hydrogenated products thereof, chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, silicone rubber, ethylene propylene copolymer, ethylene propylene diene copolymer and the like. . When weather resistance is required, a rubber-like polymer other than the conjugated diene rubber is preferred, and silicon rubber is particularly preferred from the viewpoint of moldability and electrical properties.

Here, the silicone rubber will be described in more detail. As the silicone rubber, one obtained by crosslinking or condensing liquid silicone rubber is preferable. Liquid silicone rubber strain rate is a viscosity 10 ^- preferably has the following 10 ⁵ poise at ¹ sec, condensation type, addition type, may be any of vinyl group and a hydroxyl group-containing type. Specific examples include dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, and methylphenyl vinyl silicone raw rubber. Among these, as the vinyl group-containing silicone rubber, usually, dimethyldichlorosilane or dimethyldialkoxysilane, in the presence of dimethylvinylchlorosilane or dimethylvinylalkoxysilane,
It can be obtained by hydrolysis and condensation, followed by fractionation by repeated dissolution-precipitation.

In the case of those containing a vinyl group at both terminals, a cyclic siloxane such as octamethylcyclotetrasiloxane is anionically polymerized in the presence of a catalyst, and the polymerization is terminated by using a terminal terminator to form a polymer. When obtaining, it can be obtained by using, for example, dimethyldivinylsiloxane as a terminal stopper, and appropriately selecting reaction conditions (eg, the amount of the cyclic siloxane and the amount of the terminal stopper). Here, examples of the catalyst include alkalis such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide or silanolate solutions thereof, and the like.
The reaction temperature is, for example, 80 to 130 ° C.

The hydroxyl group-containing silicone rubber is generally prepared by converting dimethyldichlorosilane or dimethyldialkoxysilane into a hydrosilane compound such as dimethylhydrochlorosilane, methyldihydrochlorosilane or dimethylhydroalkoxysilane.
It can be obtained by hydrolysis and condensation, followed by fractionation by repeated dissolution-precipitation. In addition, when the cyclic siloxane is anionically polymerized in the presence of a catalyst and the polymerization is terminated using a terminal stopper to obtain a polymer, the reaction conditions (for example, the amount of the cyclic siloxane and the amount of the terminal stopper) are selected. Can be obtained by using dimethylhydrochlorosilane, methyldihydrochlorosilane or dimethylhydroalkoxysilane as a terminal stopper. Here, examples of the catalyst include alkalis such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide and silanolate solutions thereof, and the reaction temperature is, for example, 80 to 130 ° C.
Is mentioned.

The molecular weight (weight average molecular weight in terms of standard polystyrene) of the rubbery polymer is preferably 10,000 to 40,000. The molecular weight distribution index of the rubbery polymer component (the ratio of the weight average molecular weight in terms of standard polystyrene to the number average molecular weight in terms of standard polystyrene (hereinafter referred to as "Mw / Mn"))
Is 2.0 in terms of heat resistance of the obtained conductive elastomer.
The following is preferred.

Examples of the conductive particles include known single conductive metal particles such as iron, copper, zinc, chromium, nickel, silver, cobalt, and aluminum, and alloy conductive metal particles comprising two or more of these metal elements. Can be mentioned. Of these, simple conductive metal particles such as nickel, iron, and copper are preferable in terms of economy and conductive characteristics,
Particularly preferred are nickel particles whose surface is coated with gold.

When silicon rubber is used as the insulator, the coverage of the conductive particles with the silane coupling agent is preferably 5% or more, and more preferably 7 to 5.
It is 100%, more preferably 10 to 100%, particularly preferably 20 to 100%. Further, the particle diameter of the conductive particles is preferably 1 to 1000 μm, more preferably 2 to 500 μm, more preferably 5 to 300 μm, and particularly preferably 10 to 200 μm. The particle size distribution (Dw / Dn) of the conductive particles is preferably 1 to 10, more preferably 1.01 to 7, more preferably 1.05 to 5, and particularly preferably 1.1 to 4. The water content of the conductive particles is 5%.
Is preferably 3% or less, more preferably 2% or less, particularly preferably 1% or less. According to the conductive particles having a particle size in such a range, in the obtained conductive elastomer, sufficient electric contact can be obtained between the conductive particles at the time of use. The shape of the conductive particles is not particularly limited.
It is preferably spherical or star-shaped from the viewpoint of easy dispersion in the component and the component (b) or a mixture thereof.

The nickel particles whose surfaces are particularly preferably used as the conductive particles in the present invention are coated with gold by electroless plating or the like, for example. Thus, the nickel particles having a gold coating on the surface have extremely low contact resistance. When coating gold by plating, the film thickness is 10
It is preferably at least 00 angstroms. Also,
The plating amount is preferably 1% by weight or more of the particles, more preferably 2 to 10% by weight, and particularly preferably 3 to 7% by weight.

In the present invention, the conductive particles are used in an amount of 30 to 1000 parts by weight, preferably 50 to 100 parts by weight, per 100 parts by weight of the rubbery polymer.
Used in proportions of up to 750 parts by weight. When this ratio is less than 30 parts by weight, the obtained conductive elastomer does not have a sufficiently low electric resistance value even during use, and therefore does not have a good connection function. The cured elastomer becomes brittle, making it difficult to use as a conductive elastomer. The composition for a conductive elastomer of the present invention containing the above rubbery polymer and conductive particles, if necessary, contains an ordinary silica powder, colloidal silica, airgel silica, and an inorganic filler such as alumina. be able to. By including such an inorganic filler, the thixotropy at the time of uncuring is ensured, the viscosity is increased, the dispersion stability of the conductive particles is improved, and the strength of the elastomer after curing is improved.

The amount of the inorganic filler used is not particularly limited. However, if the amount is too large, it is not preferable because the orientation of the conductive metal particles by the magnetic field cannot be sufficiently achieved. The viscosity of the composition for a conductive elastomer of the present invention is 100,000 to 1,000,000 c at a temperature of 25 ° C.
It is preferably within the range of p. The composition for a conductive elastomer of the present invention has a function as a conductive elastomer by being crosslinked or condensed to form a highly elastic elastomer and containing a specific conductive particle component. Becomes

The conductive elastomer composition of the present invention comprises:
A curing catalyst can be used for curing. Examples of such a curing catalyst include an organic peroxide, a fatty acid azo compound, a hydroxylation catalyst, and radiation.
Examples of the organic peroxide include benzoyl peroxide, bisdicyclobenzoyl peroxide, dicumyl peroxide, and ditertiary butyl peroxide. Examples of the fatty acid azo compound include azobisisobutyronitrile. Specific examples of the catalyst that can be used as the hydrosilylation reaction catalyst include chloroplatinic acid and salts thereof, and platinum-
Siloxane complex containing unsaturated group, complex of vinylsiloxane and platinum, complex of platinum and 1,3-divinyltetramethyldisiloxane, complex of triorganophosphine or phosphite and platinum, acetylacetonate platinum chelate, cyclic diene And known complexes such as complexes of platinum with platinum.

The method of adding the curing catalyst is not particularly limited. However, from the viewpoints of storage stability and prevention of uneven distribution of the catalyst at the time of mixing the components, the curing catalyst may be added to the main component (a) in advance. preferable. It is preferable to use an appropriate amount of the curing catalyst in consideration of the balance between the actual curing speed and the pot life. Further, a hydrosilylation reaction control agent such as an amino group-containing siloxane or a hydroxy group-containing siloxane, which is usually used for controlling the curing rate and the pot life, can be used in combination.

The above-described anisotropic conductive sheet is manufactured, for example, as follows. First, an insulating elastic polymer material,
For example, a molding material made of a fluid mixture is prepared by dispersing conductive magnetic particles such as nickel in silicon rubber, and placed in the cavity of the mold of the present invention as shown in FIG. This mold includes an upper mold and a lower mold, each of which forms an electromagnet, as shown in FIG. 12, and is in a state where a gap in which a molding material is arranged is formed.

In this state, the upper and lower electromagnets are operated to apply a parallel magnetic field in the thickness direction of the molding material. As a result, in the molding material layer, a stronger parallel magnetic field is applied in the thickness direction in the ferromagnetic material portion than in the other portions (non-magnetic material portion). The conductive magnetic material particles in the inside gather in a magnetic force part by the ferromagnetic material part and are further oriented in the thickness direction. Then, an anisotropic conductive sheet including a conductive portion and an insulating portion is manufactured by performing a hardening treatment by heating or the like while the parallel magnetic field is applied or after removing the parallel magnetic field.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto. [Mold manufacturing example] 150mm in height, 200mm in width, thickness 80
On a substrate 1b made of a peelable copper plate having a thickness of 50 μm,
m of the photoresist film was provided. Next, Fig. 1
A film mask 6 having a pattern such as 0 is positioned and installed, and an ultra-high pressure mercury lamp is used as a light source at 90 mJ /
After contact exposure with an exposure amount of cm ^2, a 1% aqueous solution of sodium carbonate (solution temperature: 30 ° C.) was used as a developing solution and spray-developed for 2 minutes to form a photocurable resin layer as shown in FIG.

The surface of the substrate on which the photocurable resin layer is not formed is masked with a resist tape except for a portion to be used as a lead electrode portion for plating, and then, in an iron plating bath mainly containing iron sulfamate, By performing a plating process at a temperature of 60 ° C. and a current value of 3 A / dm ² for 2 hours, a ferromagnetic material portion was formed as shown in FIG. Then, the surface was polished by a lapping device at 80 rpm for 30 minutes using a diamond abrasive compound as an abrasive, and the surface was flattened as shown in FIG. Next, the substrate is placed in a stripper (solution temperature 55 ° C.) containing a 5% aqueous sodium hydroxide solution as a main component.
By immersing for 0 minutes, the photocurable resin layer is removed,
A second non-magnetic layer as shown in FIG. 4 was obtained.

On the other hand, as shown in FIG.
A 200 μm-thick thermosetting resin sheet (glass fiber reinforced prepreg) 2C was stacked on a substrate 1 made of a soft iron plate having a width of 200 mm and a thickness of 5 mm. At a position corresponding to the magnetic material portion (3) in the thermosetting resin sheet 2C, a diameter of 0.1 mm is set by a numerically controlled carbon dioxide laser processing apparatus.
2mm through hole (3HC) is formed and through hole (3HC)
The inside was filled with iron particles having an average particle diameter of 10 μm for about 8 minutes using a rubber squeegee to obtain a first nonmagnetic layer shown in FIG. Next, the first non-magnetic layer of FIG. 6 and the second non-magnetic layer of FIG. 4 were aligned as shown in FIG. 7, and the two magnetic portions 3 and 3 ′ were aligned. Then, under a reduced pressure atmosphere of 10 Pa, a maximum press pressure of 40 kg / cm ² and a maximum temperature of 175 ° C. are applied for 2 hours in a vacuum press machine, followed by thermocompression bonding. Thereafter, as shown in FIG. The copper foil 1b was peeled off to form a lower mold for an anisotropic conductive sheet manufacturing mold (FIG. 9).

In the same manner as described above, an upper mold having a pattern in which the arrangement of the non-magnetic material portion and the ferromagnetic material portion had a mirror image relationship with the lower mold was obtained.

[Production Example of Anisotropic Conductive Sheet] As shown in FIG. 11, the upper mold and the lower mold obtained by the above-mentioned mold production example are combined, and a spacer is provided between the upper mold and the lower mold. A sheet 7 having a thickness of 70 μm was used, and a molding material 8 composed of a room-temperature-curable silicone rubber composition in which nickel particles having an average particle diameter of 40 μm were mixed at a ratio of 25% by volume was injected between the molds. After the upper molds of the molds were aligned and superimposed, and heated at 120 ° C. for 30 minutes in a state where a magnetic field of 3000 gauss was applied by a heating device 10 having a parallel magnetic pole plate 9 as shown in FIG. Then, the mold was removed to obtain an anisotropic conductive sheet 11 as shown in FIG.
The thickness of this sheet was 200 μm, and the average center-to-center distance between adjacent conductive portions was 250 μm.

[Evaluation of Anisotropic Conductive Sheet] The anisotropic conductive sheet obtained in the production example of the anisotropic conductive sheet is shown in FIG.
As shown in FIG. 4, when the resistance of each conductive portion 16 was measured using a resistance measuring device including a resistance measuring device 12, a short-circuit plate 13, a probe pin 14, and a lead wire 15,
Complete conduction is obtained with all conductive parts, and the resistance value is 15 m
It was in the range of Ω to 33 mΩ, which was very low. As shown in FIG. 15, when the short-circuit resistance between the adjacent conductive parts was measured, the resistance was 2 MΩ.
As described above, good insulation resistance was exhibited. In addition, as a result of repeating the production of the anisotropic conductive sheet using the mold, it was confirmed that the non-magnetic portion had a durability six times or more as compared with the mold having only the radiation-curable resin. Was.

[0040]

As described above in detail, the mold for producing an anisotropic conductive sheet according to the present invention has a non-magnetic material portion composed of a laminate of a non-magnetic metal layer and a heat-resistant polymer substance, The magnetic part is a mold made of a magnetic metal column and a magnetic metal powder. In this mold, it is possible to form a ferromagnetic material portion on, for example, a non-magnetic metal thin film by photolithography and plating, and then remove the portion corresponding to the ferromagnetic material portion and strengthen the portion. By laminating a thermosetting heat-resistant resin sheet filled with magnetic metal particles so that the ferromagnetic portions overlap each other, the pattern of the ferromagnetic portion and the non-magnetic portion is complicated and fine. However, it is a mold for producing an anisotropic conductive sheet which can be produced very easily and reliably by forming a mosaic layer, and has good durability against repeated use. Further, according to the mold of the present invention, a sheet having a complicated pattern of arrangement of conductive portions and insulating portions, a small center-to-center distance between adjacent conductive portions, and good anisotropic conductivity is manufactured. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a resist layer is formed by a photolithographic technique in an example.

FIG. 2 is an explanatory view showing a state in which a ferromagnetic material portion is formed by an electrolytic plating method in an example.

FIG. 3 is an explanatory view showing a state after polishing a surface on which a photocurable resin layer and a ferromagnetic portion are formed in an example.

FIG. 4 is an explanatory view showing a state in which the photocurable resin layer is removed in the example.

FIG. 5 is an explanatory view showing a state in which a thermosetting resin sheet is adhered to an upper portion of a substrate and a hole is made in a ferromagnetic material portion in the example.

FIG. 6 is an explanatory view showing a state in which ferromagnetic metal particles are filled in a thermosetting resin sheet having perforated holes attached to a substrate in an example.

FIG. 7 is an explanatory view showing a state in which a thermosetting resin sheet having a perforated hole and a peelable metal substrate on which a ferromagnetic material portion is formed by electrolytic plating are aligned with the substrate in the embodiment. It is.

FIG. 8 shows a peelable support after a thermosetting resin sheet having a perforated hole and a peelable metal substrate on which a ferromagnetic portion is formed by electrolytic plating is laminated on a substrate in an embodiment. It is explanatory drawing which shows the state by which the layer was peeled and removed.

FIG. 9 is an explanatory view showing a configuration of a mold for producing an anisotropic conductive sheet of the present invention in an example.

FIG. 10 is an explanatory diagram of a film mask having a radiation shielding portion having a pattern corresponding to a ferromagnetic portion of a mold according to an example.

FIG. 11 is an explanatory view showing a state in which an anisotropic conductive sheet material is injected into a mold in Examples.

FIG. 12 is an explanatory diagram illustrating a configuration of an anisotropic conductive sheet manufacturing apparatus in an example.

FIG. 13 is an explanatory diagram of an anisotropic conductive sheet manufactured in an example.

FIG. 14 is an explanatory view showing the configuration of an apparatus for measuring the resistance of the conductive portion of the anisotropic conductive sheet manufactured in the example.

FIG. 15 is an explanatory view showing a configuration of an apparatus for measuring a resistance between conductive portions of an anisotropic conductive sheet manufactured in an example.

[Explanation of symbols]

Reference Signs List 1 substrate 1c peelable copper foil substrate 1a second nonmagnetic layer 2 first nonmagnetic layer 1b peelable support layer 2a photocurable resin layer 2C thermosetting resin sheet 3HC Position corresponding to ferromagnetic material portion Hole 3, ferromagnetic material part 3 ′ ferromagnetic metal particles 4 radiation transmitting part 5 radiation shielding part 6 film mask 7 spacer 8 molding material 9 parallel magnetic field pole plate 10 heating device 11 anisotropic conductive sheet 12 resistance measuring instrument 13 Shorting plate 14 Probe pin 15 Lead wire 16 Conducting part 17 Insulating part

Claims (3)

[Claims] A magnetic material portion and a non-magnetic material portion are alternately arranged on a surface of a substrate made of a magnetic metal, wherein the non-magnetic material portion is composed of a non-magnetic metal layer and a heat-resistant polymer material layer. Wherein the magnetic material portion comprises a magnetic metal column and a magnetic metal powder. 2. The mold for producing an anisotropic conductive sheet according to claim 1, wherein said magnetic material portion is formed by laminating a magnetic metal columnar layer and a magnetic metal powder layer. 3. A method for producing an anisotropic conductive sheet using the mold for producing an anisotropic conductive sheet according to claim 1.