JP2001239526A - Mold, method of manufacturing the same, and method of manufacturing anisotropic conductive sheet - Google Patents

Abstract

(57) [Problem] To form a magnetic field having a sufficient intensity distribution with respect to a sheet molding material layer, to have a conductive part of a complicated pattern with a small pitch, and Kind Code: A1 A mold capable of forming an anisotropic conductive sheet having a required insulating property, a method for manufacturing the same, and a method for manufacturing an anisotropic conductive sheet using the mold. SOLUTION: The mold according to the present invention is a mold in which a plurality of magnetic portions are formed on a substrate made of a magnetic material while being separated from each other, and a plurality of through-holes formed on the substrate are provided. A non-magnetic material layer having a hole, and a cover member provided to close the through-hole of the non-magnetic material layer, wherein the magnetic material portion includes the substrate and the substrate in the through-hole of the non-magnetic material layer. It is composed of magnetic particles filled in a space between the cover and the cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anisotropic connector suitable for use in electrical connection between circuit devices such as electronic components and for electrical inspection of circuit devices such as printed circuit boards and semiconductor integrated circuits. The present invention relates to a mold preferably used for forming a conductive sheet and a method for producing the same, and a method for producing an anisotropic conductive sheet using the mold.

[0002]

2. Description of the Related Art An anisotropic conductive sheet is a sheet having conductivity only in a thickness direction or a pressurized conductive portion having conductivity only in the thickness direction when pressed in the thickness direction. Yes, compact electrical connection can be achieved without using means such as soldering or mechanical fitting, and soft connection is possible by absorbing mechanical shock and strain Utilizing such features, circuit devices such as printed circuit boards and leadless chip carriers, liquid crystal panels, etc., in the fields of electronic calculators, electronic digital watches, electronic cameras, computer keyboards, etc. It is widely used as a connector for achieving an electrical connection between the two.

In electrical inspection of a circuit device such as a printed circuit board or a semiconductor integrated circuit, an electrode to be inspected formed on one surface of a circuit device to be inspected and an electrode formed on the surface of the inspection circuit substrate. In order to achieve electrical connection with the test electrode, an anisotropic conductive sheet is interposed between the test electrode region of the circuit device and the test electrode region of the test circuit board. .

Conventionally, as such an anisotropic conductive sheet, those having various structures are known.
Patent Document 1-93393 discloses an anisotropic conductive sheet obtained by uniformly dispersing metal particles in an elastomer (hereinafter, referred to as an anisotropic conductive sheet).
This is called a “dispersed anisotropic conductive sheet”. JP-A-53-147772 discloses that a large number of conductive portions extending in the thickness direction are formed by distributing conductive magnetic particles unevenly in an elastomer. An anisotropic conductive sheet formed with an insulating portion to be insulated (hereinafter referred to as an “eccentrically-distributed anisotropic conductive sheet”) is disclosed. Further, JP-A-61-250906 discloses a sheet. An unevenly distributed anisotropic conductive sheet in which a step is formed between a surface of a conductive portion and an insulating portion is disclosed. Then, since the unevenly distributed anisotropic conductive sheet has a conductive portion formed in accordance with the pattern opposite to the electrode pattern of the circuit device to be connected, it should be connected compared to the dispersed type anisotropic conductive elastomer sheet. This is advantageous in that electrical connection between the electrodes can be achieved with high reliability even in a circuit device in which the electrodes are arranged at a small pitch.

[0005] As a method for producing the above-described unevenly distributed anisotropic conductive sheet, a special anisotropic conductive sheet molding die is used, and a curing space is formed in the molding space of the anisotropic conductive sheet molding die. Forming a sheet molding material layer containing conductive particles exhibiting magnetism in a material for a polymer substance to be an elastic polymer substance, and having a strength distribution in the thickness direction with respect to the sheet molding material layer. A magnetic field is applied, and the conductive particles are moved by the action of the magnetic force to be aggregated in a portion to be a conductive portion, and further the conductive particles are oriented so as to be aligned in a thickness direction, and the sheet molding material layer is cured in that state. There are known ways to do this.

The anisotropic conductive sheet molding dies used in the above-described method for producing an anisotropic conductive sheet have an upper plate and a lower die, each of which has a substantially flat plate shape and correspond to each other. The mold and the lower mold are configured to be attachable to the electromagnet, or are configured integrally with the electromagnet, and have a structure capable of heating and curing the sheet molding material layer while applying a magnetic field to the sheet molding material layer. is there. Further, in order to form a conductive portion at an appropriate position by applying a magnetic field to the sheet molding material layer, the upper mold, or both the upper mold and the lower mold in the anisotropic conductive sheet molding mold are made of iron, nickel, or the like. On a substrate made of a ferromagnetic material, 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 nonmagnetic metal or resin such as copper. Are arranged in a mosaic pattern (hereinafter, referred to as a “mosaic layer”), and the molding surfaces of the upper mold and the lower mold are flat or conductive of an anisotropic conductive sheet to be formed. It has slight irregularities corresponding to the portions.

According to the anisotropic conductive sheet molding die described above, a magnetic field having an intensity distribution can be formed on the sheet molding material layer by an electromagnet. In such an anisotropic conductive sheet molding die, the arrangement, shape, and the like of the ferromagnetic portion and the nonmagnetic portion in the mosaic layer are determined based on the anisotropic conductive sheet to be formed. That is, the ferromagnetic portion is disposed at a position corresponding to the conductive portion of the anisotropic conductive sheet, and the shape of the ferromagnetic portion is adapted to the cross-sectional shape of the conductive portion. And it has a conductive part of a complicated pattern with a small pitch, and
In order to produce an anisotropic conductive sheet having a required insulating property between adjacent conductive portions, a magnetic field having a sufficient intensity distribution is applied to the sheet forming material layer, that is, the conductive property in the sheet forming material layer is increased. It is necessary to apply a magnetic field having a much higher intensity to a portion where a portion is to be formed (hereinafter also referred to as a “conductive portion forming portion”) than to a portion other than the conductive portion forming portion. In a mold for forming an electroconductive sheet, it is required to form a mosaic layer having a ferromagnetic portion having a high aspect ratio (ratio of thickness to diameter or width).

Conventionally, as a method of forming a mosaic layer in the production of a mold for forming an anisotropic conductive sheet, the following method is known. (1) A portion constituting a nonmagnetic portion is removed from a plate made of a ferromagnetic material by etching, and a resin is poured into the formed removed portion, or a nonmagnetic metal such as copper is plated by plating. A method of filling a magnetic material to form a mosaic layer. (2) A portion constituting a non-magnetic material portion is removed from the ferromagnetic plate by cutting, and a resin is poured into the formed removed portion or a non-magnetic metal such as copper is plated to form a non-magnetic material. A method of filling a magnetic material to form a mosaic layer. (3) A non-magnetic material portion made of a radiation-curable resin having through holes formed according to an array pattern of the ferromagnetic material portions to be formed is formed on the surface of a plate-like material made of a ferromagnetic material by a photolithography technique. Thereafter, a ferromagnetic material is filled in the through-hole formed in the non-magnetic material portion by plating to form a mosaic layer (Japanese Patent Laid-Open No. 6-103).
No. 820). (4) A non-magnetic portion made of a radiation-curable resin having through holes formed in accordance with an arrangement pattern of ferromagnetic portions to be formed is formed on the surface of a plate made of a ferromagnetic material by photolithography. After that, the ferromagnetic particles are filled into the through holes formed in the non-magnetic material portion, and a curable resin material is filled as a binder for fixing the ferromagnetic particles, and the method is followed by curing. Kaihei 7-
No. 1355062).

However, the mold for forming an anisotropic conductive sheet obtained by the above method has the following problems. When the mosaic layer is formed by the method (1), since the side etching occurs, the pitch of the ferromagnetic portions, that is, the distance between the centers of the adjacent ferromagnetic portions is small, and the mosaic has a high aspect ratio. Forming the layers is quite difficult. When the mosaic layer is formed by the method (2), it is possible to form a mosaic layer in which the pitch of the ferromagnetic portions is smaller than in the method (1). However, in order to form a complex mosaic layer in which the arrangement pattern of the ferromagnetic portions is complicated, it takes too much work and time, and therefore, the resulting anisotropic conductive sheet molding die has a high manufacturing cost. Or it cannot be manufactured in practice.

When the mosaic layer is formed by the method (3), a metal material which can be plated, such as nickel, is used as a material for forming the ferromagnetic material portion. Although nickel shows ferromagnetism, it has a smaller magnetization intensity than iron, cobalt, etc., so it is possible to form a ferromagnetic material part with a high aspect ratio. Even if it is, it is difficult to form a magnetic field having a sufficient intensity distribution with respect to the sheet forming material layer. The required insulation cannot be obtained between the conductive parts. In the case where the mosaic layer is formed by the method (4), a non-magnetic curable resin material is used as a binder for the ferromagnetic particles, so that the density of the ferromagnetic material in the ferromagnetic portion decreases. Eventually, it becomes difficult to form a magnetic field having a sufficient intensity distribution on the sheet molding material layer,
Therefore, when the pitch of the conductive portions of the intended anisotropic conductive sheet is small, required insulation between the adjacent conductive portions cannot be obtained.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the invention is to provide a magnetic field having a sufficient intensity distribution with respect to a sheet molding material layer. To provide a mold which can be formed, has a conductive portion having a small pitch and a complicated pattern, and can form an anisotropic conductive sheet having a required insulating property between the conductive portions. It is in. A second object of the present invention is to form a magnetic field having a sufficient intensity distribution with respect to a sheet molding material layer, to have a conductive pattern having a small pitch and a complicated pattern, and It is an object of the present invention to provide a method capable of manufacturing a mold capable of forming an anisotropic conductive sheet having a required insulating property. A third object of the present invention is to provide a method for manufacturing an anisotropic conductive sheet having a required insulating property between adjacent conductive parts even if the conductive parts have a small pitch and a complicated pattern. Is to provide.

[0012]

A mold according to the present invention is a mold in which a plurality of magnetic parts are provided apart from each other on a substrate made of a magnetic substance, and is formed on the substrate. A non-magnetic layer having a plurality of through-holes, and a cover material provided to cover the through-holes of the non-magnetic layer, wherein the magnetic portion is formed in the through-hole of the non-magnetic layer. It is characterized by being formed of magnetic particles filled in a space between the substrate and the lid member.

In such a mold, the ratio of the magnetic particles filled in the space occupying the space between the substrate and the lid member in the through hole of the nonmagnetic layer is 3%.
It is preferably at least 0% by volume.

[0014] The mold of the present invention is a mold in which a plurality of magnetic parts are formed on a substrate made of a magnetic material while being separated from each other. A non-magnetic layer having a through-hole, and a cover material provided to close the through-hole of the non-magnetic layer, the magnetic portion includes the substrate in the through-hole of the non-magnetic layer. It is characterized by comprising magnetic particles filled in the space between the lid material and a magnetic phase formed around the magnetic particles.

The mold of the present invention can be preferably used as a mold for forming an anisotropic conductive sheet. In the mold of the present invention, it is preferable that the nonmagnetic layer is made of a resin material cured by radiation. Further, it is preferable that the lid member is made of a resin material cured by heat or radiation.

According to the method of manufacturing a mold of the present invention, a nonmagnetic layer having a plurality of through holes is formed on a substrate made of a magnetic material, and magnetic particles are filled in the through holes of the nonmagnetic layer. And
A step of forming a cover material on the nonmagnetic layer so as to cover the through hole.

Further, according to the method of manufacturing a mold of the present invention, a nonmagnetic layer having a plurality of through holes is formed on a substrate made of a magnetic substance, and magnetic particles are contained in the through holes of the nonmagnetic layer. To form a magnetic phase around the magnetic particles by plating the magnetic particles filled in the through-holes of the nonmagnetic layer with a magnetic metal, thereby forming the nonmagnetic material. The method is characterized by having a step of forming a lid material on the layer so as to close the through hole.

In such a method of manufacturing a mold, after the magnetic particles are filled in the through-holes of the non-magnetic layer, the magnetic particles may leak from the through-holes into the non-magnetic layer. Preferably, a temporary lid is formed so that the plating solution can pass through, and the magnetic particles filled in the through-holes of the nonmagnetic layer in the plating solution are plated with a magnetic metal.

The method for producing an anisotropic conductive sheet of the present invention comprises:
A method for manufacturing an anisotropic conductive sheet in which a plurality of conductive portions extending in the thickness direction are arranged in a state in which they are insulated from each other by an insulating portion, using the above-described mold, and cured in a mold. A sheet molding material containing conductive particles exhibiting magnetism in a material for an elastic polymer to be an elastic polymer substance is filled, and a magnetic field having an intensity distribution is applied to the sheet molding material via the mold. And a step of curing the sheet molding material.

[0020]

(1) The magnetic portion is mainly composed of magnetic particles, and there is no limitation on the type of magnetic material forming the magnetic particles. A material having a large magnetization intensity can be used. (2) The magnetic particles are fixed by filling the space between the substrate and the cover material in the through holes of the nonmagnetic layer, and fix the magnetic particles in forming the magnetic part. Therefore, it is not necessary to use a binder made of a non-magnetic material, so that a magnetic material portion having a high density of a magnetic material can be formed. (3) By forming a magnetic phase around the magnetic particles, a magnetic part having an extremely high density of the magnetic material can be formed. (4) The size of the magnetic portion can be determined according to the size of the through-hole of the non-magnetic layer, and by using a resin material cured by radiation as a material forming the non-magnetic layer, Since the nonmagnetic layer can be formed by photolithography, a magnetic part having a high aspect ratio can be formed even if the pitch of the target magnetic part is small.

[0021]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory cross-sectional view showing a configuration of a main part of a lower mold in an example of a mold for forming an anisotropic conductive sheet according to the present invention. In the lower mold for forming the anisotropic conductive sheet, a nonmagnetic layer 20 having a plurality of through holes 21 is formed on a substrate 10 made of a ferromagnetic material. Each of the holes 21 is provided with a lid member 22 so as to close the opening of the through hole 21. The pattern of the through-holes 21 of the non-magnetic material part 20 is a pattern corresponding to the pattern of the conductive part of the anisotropic conductive sheet to be formed. The space between the substrate 10 and the cover member 22 in each through hole 21 of the non-magnetic layer 20 is filled with, for example, spherical magnetic particles 26. A magnetic part 25 is formed therein. The mold for forming an anisotropic conductive sheet in this example is for forming an anisotropic conductive sheet having a conductive portion protruding from the surface of an insulating portion, and includes a nonmagnetic material layer 2.
A cavity forming layer 30 having a hole 31 at a position located on the lid member 22 is integrally formed on the surface of the cover member 22.
The hole 31 in the cavity forming layer 30 is for forming a conductive part protruding from the surface of the insulating part.

The magnetic material constituting the substrate 10 is iron,
A ferromagnetic material such as nickel, cobalt, or an alloy thereof can be used. The thickness of the substrate 10 is preferably 0.05 to 20 mm, more preferably 1.5 to 10 mm
It is. The surface of the substrate 10 is smooth,
It is preferable to use one chemically degreased and mechanically polished.

The material constituting the non-magnetic layer 20 is cured by radiation in that the non-magnetic layer 20 having the through holes 21 can be easily formed with high dimensional accuracy by a photolithography technique. It is preferably a resin material. As the radiation-sensitive resin material for forming the nonmagnetic layer 20, a photoresist such as an acrylic dry film resist, an epoxy liquid resist, or a polyimide liquid resist can be used.
The thickness of the nonmagnetic layer 20 is preferably 20 μm or more, and more preferably 25 to 500 μm. This thickness is 20
When the thickness is less than μm, the thickness of the space for forming the magnetic body portion 25 becomes too small, and it becomes difficult to apply a magnetic field having an intended intensity distribution to the sheet molding material layer. There is.

It is preferable to use a thermosetting or radiation-curable resin material as a material for forming the lid member 22 because the lid member 22 can be easily formed.
Specific examples of such a resin material include an acrylic resin, an epoxy resin, polyimide, and polysilazane. The thickness of the lid member 22 is preferably 10 to 10
0 μm, more preferably 20 to 50 μm. If the thickness is less than 10 μm, the strength of the lid member 22 is low, so that it may be difficult to obtain a mold having sufficiently high durability. On the other hand, if the thickness exceeds 100 μm, it may be difficult to apply a high-intensity magnetic field to the conductive portion forming portion in the sheet molding material layer.

A space between the substrate 10 and the lid member 22 (hereinafter, referred to as a space)
It is also referred to as “magnetic body part forming space”. ) Is preferably 10 μm or more, more preferably 25 μm or more.
When the thickness of the magnetic body part formation space is less than 10 μm, it may be difficult to apply a strong magnetic field to the conductive part formation part in the sheet molding material layer. The aspect ratio of the magnetic body part formation space (the aspect ratio of the magnetic body part 25) is preferably 0.7 or more,
It is more preferably 0.9 or more. If the aspect ratio is less than 0.7, it may be difficult to apply a magnetic field having an intended intensity distribution to the sheet molding material layer.

As the magnetic particles 26 constituting the magnetic portion 25, particles made of a ferromagnetic material such as iron, nickel, cobalt, or an alloy thereof can be used. Particles composed of iron or an alloy thereof are preferred because of their large size. The particle diameter of the magnetic particles 26 is
The material is not particularly limited as long as it can be filled in the magnetic material portion forming space, but it is preferably 2 to 100 μm, particularly preferably 20 to 70 μm in terms of easy handling and easy filling operation.

The ratio of the magnetic particles 26 filled in the magnetic part forming space to the magnetic part forming space is preferably 30% by volume or more, more preferably 50% by volume or more, and particularly preferably 60% by volume or more. % By volume or more. If this ratio is less than 30% by volume, it may be difficult to apply a high-intensity magnetic field to the conductive portion of the sheet molding material layer.

The material forming the cavity forming layer 30 is as follows:
A resin material cured by radiation is preferable because the cavity forming layer 30 having the holes 31 can be formed with high dimensional accuracy by a photolithography technique. As the radiation-sensitive resin material for forming the cavity forming layer 30, a photoresist such as an acrylic dry film resist, an epoxy liquid resist, or a polyimide liquid resist can be used. May be the same as the radiation-sensitive resin material for forming the non-magnetic material, provided that the adhesiveness to the non-magnetic material layer 20 in the obtained cavity forming layer 30 is ensured. The radiation-sensitive resin material for forming the layer 20 may be of a different type. The thickness of the cavity forming layer 30 is designed according to the protruding height of the conductive portion in the anisotropic conductive sheet to be formed, but is preferably 5 to 200 μm, more preferably 1 to 200 μm.
5 to 60 μm.

The mold for forming an anisotropic conductive sheet in this embodiment is composed of the lower mold described above and an upper mold that is paired with the lower mold. The upper mold has basically the same configuration as the lower mold except that the magnetic body is arranged in a pattern opposite to the magnetic body of the lower mold.

The above-described mold for forming an anisotropic conductive sheet can be manufactured, for example, as follows. First, as shown in FIG. 2, a substrate 10 made of a magnetic material is prepared, and a nonmagnetic layer 20 having a plurality of through holes 21 is formed on the substrate 10. As a means for forming the nonmagnetic layer 20, a photolithography technique can be used. Specifically, a photoresist layer is formed on the substrate 10, and the through holes 21 to be formed are formed on the photoresist layer.
A mask on which a radiation shielding portion is formed in accordance with the pattern corresponding to the above is arranged, and thereafter, the photoresist layer is subjected to radiation irradiation processing and development processing. As a method of forming a photoresist layer, a method of applying a liquid photoresist on the surface of the substrate 10 by a method such as screen printing, spin coating, or applicator coating, or laminating a dry film photoresist on the surface of the substrate 10 And the like. When the non-magnetic layer 20 having a large thickness is formed, the non-magnetic layer 2 to be formed is formed.
Forming a photoresist layer having a thickness smaller than 0;
By repeating the step of performing the radiation treatment and the development treatment on the photoresist layer a plurality of times, the nonmagnetic layer 20 having the target thickness can be formed.

Next, as shown in FIG.
0 through holes 21 are filled with magnetic particles 26, and then
As shown in FIG. 4, the through holes 2 are formed on the nonmagnetic layer 20.
The cover material forming material layer 22A made of a curable resin material is formed so as to cover the first material. As a method of forming the lid material forming material layer 22A, a method of applying a liquid curable resin material to the surface of the nonmagnetic material layer 20 by a method such as screen printing, spin coating, or applicator coating, or a curable resin sheet Is disposed on the surface of the non-magnetic layer 20. Then, a curing treatment of the lid material forming material layer 22A,
Specifically, a heat treatment, a thermocompression treatment, or a radiation irradiation treatment is performed, and then the surface of the obtained cured resin layer is polished to form the nonmagnetic material layer 20 as shown in FIG.
Is formed, which covers the opening of the through hole 21 in FIG.

Next, as shown in FIG.
0, a photoresist layer is formed on the surface of the lid member 22, and a mask on which a radiation shielding portion is formed in accordance with a pattern corresponding to the through hole 21 of the nonmagnetic layer 20 is arranged on the photoresist layer. By performing radiation irradiation processing and development processing on the photoresist layer,
The cavity forming layer is formed, and the lower mold having the configuration shown in FIG. 1 is manufactured. Then, the upper mold is manufactured by basically the same method as the above-described method of manufacturing the lower mold, thereby manufacturing the desired anisotropic conductive sheet molding die.

According to the mold for forming an anisotropic conductive sheet as described above, the magnetic part 25 is constituted by the magnetic particles 26, and the type of the magnetic material forming the magnetic particles 26 is as follows. Since there is no limitation, a magnetic material having a high magnetization strength can be used as the magnetic material constituting the magnetic body portion 20. In addition, the magnetic particles 26 are formed in the non-magnetic layer 2.
In the through-hole 21, the space between the substrate 10 and the cover member 22 is fixed by being filled, and in forming the magnetic body portion 25, a non-magnetic material is used to fix the magnetic particles 26. Since it is unnecessary to use a binder made of a magnetic material, the magnetic material portion 25 having a high density of the magnetic material can be formed. Therefore, it is possible to cause a magnetic field having a sufficient intensity distribution to act on the sheet molding material layer, and to have a conductive portion having a small pitch and a complicated pattern,
In addition, it is possible to form an anisotropic conductive sheet having required insulation between adjacent conductive portions.

The size of the magnetic portion 25 can be determined according to the size of the through-hole 21 of the non-magnetic layer 20, and the material constituting the non-magnetic layer 20 is a resin material cured by radiation. Is used, it is possible to form the nonmagnetic layer 20 by a photolithography technique. Therefore, even if the pitch of the target magnetic part 25 is small, the magnetic part having a high aspect ratio can be used. 25 can be formed with high dimensional accuracy.

FIG. 7 is an explanatory sectional view showing the structure of the main part of the lower mold in another example of the anisotropic conductive sheet molding die according to the present invention. In the lower mold of the anisotropic conductive sheet molding die, the space between the substrate 10 and the cover member 22 in the through hole 21 of the nonmagnetic layer 20 is filled with the magnetic particles 26, A magnetic phase 27 is formed around the magnetic particles 26, and a magnetic section 25 is formed by the magnetic particles 26 and the magnetic phase 27. The other configuration is the same as that of the lower die of the die for forming an anisotropic conductive sheet shown in FIG.

The magnetic material constituting the magnetic material phase 27 includes:
In that the magnetic phase 27 can be easily formed,
It is preferable to use a material capable of electroplating or electroless plating, and specific examples thereof include nickel. The total ratio of the magnetic particles and the magnetic phase filled in the magnetic part forming space in the magnetic part forming space is preferably 70% by volume or more, more preferably 80% by volume or more. If this ratio is less than 70% by volume, it may be difficult to apply a high-intensity magnetic field to the conductive portion forming portion in the sheet molding material layer. The ratio of the volume of the magnetic particles 26 to the total volume of the magnetic particles 26 and the magnetic phase 27 is preferably 70%, more preferably 80%.

The mold for forming an anisotropic conductive sheet in this embodiment is composed of the above-mentioned lower mold and an upper mold that is paired with the lower mold. The upper mold has basically the same configuration as the lower mold except that the magnetic body is arranged in a pattern opposite to the magnetic body of the lower mold.

The mold for forming an anisotropic conductive sheet described above can be manufactured, for example, as follows. First, a non-magnetic material layer 20 having a plurality of through holes 21 is formed on a substrate 10 made of a magnetic material in the same manner as in the method of manufacturing the anisotropic conductive sheet molding die having the configuration shown in FIG. (Fig. 2
The magnetic particles 26 are filled in the through holes 21 of the nonmagnetic layer 20 (see FIG. 3).

Next, as shown in FIG.
At 0, a temporary lid 23 is formed so that the magnetic particles 26 do not leak from the through hole 21 and the plating solution passes therethrough. Specifically, as shown in FIG. 9, the temporary lid 23 is formed so as to cover only the central region of the rectangular opening in the through hole 21 of the non-magnetic layer 20, and the opening edge of the through hole 21 and the temporary lid A gap having a width smaller than the particle diameter of the magnetic particles 26 is formed between the outer peripheral portion 23 and the peripheral edge of the magnetic particle 26. The width of the gap is appropriately set depending on the particle diameter of the magnetic particles 26 used, but is preferably 20 μm or more from the viewpoint that the plating solution can easily pass through. As a means for forming such a temporary lid 23, a photolithography technique can be used. Specifically, a photoresist layer is formed on the nonmagnetic layer 20, and a mask on which a radiation shielding portion is formed according to a pattern corresponding to the temporary lid 23 to be formed is arranged on the photoresist layer. By performing radiation irradiation processing and development processing on the photoresist layer,
The temporary lid 23 can be formed. Then, in the plating solution, the magnetic particles 26 filled in the through holes 21 of the nonmagnetic layer 20 are plated with a magnetic metal by, for example, electrolytic plating, as shown in FIG. A magnetic phase 27 is formed around the magnetic particles 26.

Next, as shown in FIG. 11, a lid material forming material layer 22A made of a curable resin material is formed on the non-magnetic material layer 20 so as to cover the through holes 21. By performing a hardening treatment of 22A, and then polishing the surface of the obtained cured resin layer, a cover material 22 for closing the opening of the through hole 21 in the non-magnetic material layer 20 is formed as shown in FIG. .

Next, as shown in FIG. 13, a photoresist layer is formed on the surfaces of the non-magnetic layer 20 and the lid member 22, and the photoresist layer is formed on the photoresist layer so as to correspond to the through holes 21 of the non-magnetic layer 20. By arranging a mask on which a radiation shielding portion is formed according to the pattern to be formed, and then performing radiation irradiation processing and development processing on the photoresist layer,
The cavity forming layer is formed, and the lower mold having the configuration shown in FIG. 7 is manufactured. Then, the upper mold is manufactured by basically the same method as the above-described method of manufacturing the lower mold, thereby manufacturing the desired anisotropic conductive sheet molding die.

According to the above-described mold for forming an anisotropic conductive sheet, a magnetic material having a high magnetization strength can be used as the magnetic particles 26 constituting the magnetic portion 25. Around the magnetic particles 26, a magnetic phase 27
Is formed, it is possible to form the magnetic portion 25 having a very high density of the magnetic material, and therefore, it is possible to apply a magnetic field having a more sufficient intensity distribution to the sheet molding material layer, It is possible to form an anisotropic conductive sheet having a conductive portion having a small pitch and a complicated pattern and having a required insulating property between adjacent conductive portions. The size of the magnetic portion 25 can be determined according to the size of the through-hole 21 of the non-magnetic layer 20, and a resin material cured by radiation is used as the material of the non-magnetic layer 20. Accordingly, the nonmagnetic layer 20 can be formed by a photolithography technique, so that even if the pitch of the target magnetic section 25 is small, the magnetic section 25 having a high aspect ratio can be formed at a high height. It can be formed with dimensional accuracy.

According to the mold for forming an anisotropic conductive sheet of the present invention, an anisotropic conductive sheet can be manufactured, for example, as follows. First, a sheet molding material in which conductive particles exhibiting magnetism are dispersed in a material for a polymer substance which is cured to become an elastic polymer substance is prepared. As shown in FIG. 14, the sheet molding material is anisotropically conductive. The sheet molding material layer 1A is formed by injecting it into a flexible sheet molding die.

Various materials can be used as the curable polymer material used for preparing the sheet molding material. Specific examples thereof include polybutadiene rubber, natural rubber, polyisoprene rubber, and styrene-butadiene. Conjugated diene rubbers such as copolymer rubber, acrylonitrile-butadiene copolymer rubber, and hydrogenated products thereof;
Styrene-butadiene-diene block copolymer rubber,
Block copolymer rubbers such as styrene-isoprene block copolymers and hydrogenated products thereof, chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, silicone rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer And polymer rubber. In the above, when weather resistance is required for the obtained anisotropic conductive sheet, it is preferable to use a material other than the conjugated diene rubber, and particularly, from the viewpoint of moldability and electrical characteristics, use of silicone rubber Is preferred.

As the silicone rubber, those obtained by crosslinking or condensing a liquid silicone rubber are preferable. The liquid silicone rubber preferably has a viscosity of 10 ⁵ poise or less at a strain rate of 10 ⁻¹ sec, and may be any of condensation type, addition type, and those containing a vinyl group or a hydroxyl group. Good. Specifically, dimethylsilicone raw rubber, methylvinylsilicone raw rubber, methylphenylvinylsilicone raw rubber and the like can be mentioned.

Among these, liquid group-containing silicone rubber (vinyl group-containing polydimethylsiloxane)
Is usually obtained by subjecting dimethyldichlorosilane or dimethyldialkoxysilane to hydrolysis and condensation reaction in the presence of dimethylvinylchlorosilane or dimethylvinylalkoxysilane, for example, followed by fractionation by repeated dissolution-precipitation. Also,
The liquid silicone rubber containing vinyl groups at both ends is anionically polymerized with a cyclic siloxane such as octamethylcyclotetrasiloxane in the presence of a catalyst, and uses, for example, dimethyldivinylsiloxane as a polymerization terminator and other reaction conditions (for example, , The amount of the cyclic siloxane and the amount of the polymerization terminator). Here, as a catalyst for anionic polymerization, alkali such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide or a silanolate solution thereof can be used. The reaction temperature is, for example, 80 to 130 ° C. Such a vinyl group-containing polydimethylsiloxane preferably has a molecular weight Mw (weight average molecular weight in terms of standard polystyrene; the same applies hereinafter) of 10,000 to 40,000. In addition, from the viewpoint of heat resistance of the obtained anisotropic conductive sheet, the molecular weight distribution index (refers to the value of the ratio Mw / Mn between the standard polystyrene equivalent weight average molecular weight Mw and the standard polystyrene equivalent number average molecular weight Mn; the same applies hereinafter). Is preferably 2.0 or less.

On the other hand, a liquid silicone rubber containing hydroxyl groups (hydroxyl group-containing polydimethylsiloxane) is usually prepared by hydrolyzing dimethyldichlorosilane or dimethyldialkoxysilane in the presence of dimethylhydrochlorosilane or dimethylhydroalkoxysilane. And condensation reaction, for example,
It is obtained by performing fractionation by repeating precipitation.
Further, cyclic siloxane is anionically polymerized in the presence of a catalyst, and dimethylhydrochlorosilane, methyldihydrochlorosilane or dimethylhydroalkoxysilane is used as a polymerization terminator, and other reaction conditions (for example, the amount of the cyclic siloxane and the polymerization termination) are used. Amount of agent)
Can also be obtained by appropriately selecting Here, as a catalyst for anionic polymerization, alkali such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide or a silanolate solution thereof can be used. The reaction temperature is, for example, 80 to 130 ° C. Such hydroxyl group-containing polydimethylsiloxane is,
It is preferable that the molecular weight Mw is 10,000 to 40,000. Further, from the viewpoint of heat resistance of the obtained conductive path element, those having a molecular weight distribution index of 2.0 or less are preferable. In the present invention, either one of the above-mentioned vinyl group-containing polydimethylsiloxane and hydroxyl group-containing polydimethylsiloxane can be used, or both can be used in combination.

As the conductive particles used for preparing the sheet molding material, particles of magnetic metals such as nickel, iron and cobalt, particles of alloys thereof, particles containing these metals, or particles of these metals are used. The core particles are obtained by plating the surface of the core particles with a metal having good conductivity such as gold, silver, palladium, and rhodium, or inorganic particles or polymer particles such as nonmagnetic metal particles or glass beads. Particles, such as those obtained by plating the surface of the core particles with a conductive magnetic material such as nickel or cobalt, or those in which the core particles are coated with both a conductive magnetic material and a metal having good conductivity. No. In these, nickel particles are used as core particles,
It is preferable to use a material whose surface is plated with a metal having good conductivity such as gold or silver. Means for coating the surface of the core particles with a conductive metal is not particularly limited, but may be, for example, chemical plating or electroless plating.

When the conductive particles are formed by coating the surface of a core particle with a conductive metal, from the viewpoint of obtaining good conductivity, the coverage of the conductive metal on the particle surface (core particle) Is preferably 40% or more, more preferably 45% or more, and particularly preferably 47 to 95%. Further, the coating amount of the conductive metal is 0.5 to
It is preferably 50% by weight, more preferably 1 to
The content is 30% by weight, more preferably 3 to 25% by weight, particularly preferably 4 to 20% by weight. When the conductive metal to be coated is gold, the coating amount is from 2.5 to 2.5
It is preferably 30% by weight, more preferably 3 to
It is 20% by weight, more preferably 3.5 to 15% by weight. When the conductive metal to be coated is silver,
The coating amount is preferably 3 to 50% by weight of the core particles, more preferably 4 to 40% by weight, further preferably 5 to 30% by weight, particularly preferably 6 to 20% by weight.

The conductive particles have a particle size of 1 to 100.
0 μm, more preferably 2 to 50 μm.
0 μm, more preferably 5 to 300 μm, particularly preferably 10 to 200 μm. Further, the particle size distribution (Dw / Dn) of the conductive particles is preferably 1 to 10, more preferably 1.01 to 7, further preferably 1.05 to 5, and particularly preferably 1.1 to 1. 4. By using conductive particles that satisfy such conditions,
The conductive portion of the obtained anisotropic conductive sheet is easily deformed under pressure, and sufficient electrical contact between the conductive particles is obtained in the conductive portion. In addition, the shape of the conductive particles is not particularly limited. However, since the conductive particles can be easily dispersed in the polymer substance material, the conductive particles have a spherical shape, a star shape, or a secondary shape in which these are aggregated. It is preferably a lump formed by particles.

The water content of the conductive particles is preferably 5% or less, more preferably 3% or less, further preferably 2% or less, and particularly preferably 1% or less. By using the conductive particles satisfying such conditions, it is possible to prevent bubbles from being generated in the polymer material layer when the polymer material layer is cured in the manufacturing method described below or Is suppressed.

As the conductive particles, those whose surfaces have been treated with a coupling agent such as a silane coupling agent can be used as appropriate. By treating the surface of the conductive particles with the coupling agent, the adhesion between the conductive particles and the elastic polymer material is increased, and as a result, the conductive portion of the obtained anisotropic conductive sheet has a repetitive structure. The durability in use becomes high. The amount of the coupling agent used is appropriately selected within a range that does not affect the conductivity of the conductive particles. However, the coverage of the coupling agent on the surface of the conductive particles (the ratio of the coupling agent to the surface area of the conductive core particles). Is preferably 5% or more, more preferably 7 to 100%, more preferably 10 to 100%, and particularly preferably 20 to 100%.
It is an amount that becomes 100%.

The conductive particles are used in such a proportion that the proportion of the conductive particles in the conductive portion of the obtained anisotropic conductive sheet is 30 to 60% by volume, preferably 35 to 50%. Is preferred. If this ratio is less than 30%, a conductive portion having a sufficiently low electric resistance may not be obtained. On the other hand, when this ratio exceeds 60%, the conductive part of the obtained anisotropic conductive sheet tends to be fragile, and the elasticity required for the conductive part may not be obtained.

The sheet molding material may contain a curing catalyst for curing the polymer material. As such a curing catalyst, an organic peroxide, a fatty acid azo compound, a hydrosilylation catalyst, or the like can be used. Specific examples of the organic peroxide used as the curing catalyst include benzoyl peroxide, bisdicyclobenzoyl peroxide, dicumyl peroxide, and ditertiary butyl peroxide. Specific examples of the fatty acid azo compound used as a curing catalyst include azobisisobutyronitrile. Specific examples of the catalyst which can be used as a catalyst for the hydrosilylation reaction include chloroplatinic acid and salts thereof, a siloxane complex containing a platinum-unsaturated group, a complex of vinylsiloxane and platinum, and platinum and 1,3-divinyltetramethyldisiloxane. And a complex of triorganophosphine or phosphite with platinum, acetylacetate platinum chelate, and a complex of cyclic diene and platinum. The amount of the curing catalyst used is appropriately selected in consideration of the type of the polymer material, the type of the curing catalyst, and other curing conditions. 15 parts by weight.

Further, the sheet molding material may contain an inorganic filler such as ordinary silica powder, colloidal silica, airgel silica, and alumina, if necessary. By including such an inorganic filler,
The thixotropy of the sheet molding material is ensured, the viscosity is increased, and the dispersion stability of the conductive particles is improved, and the strength of the obtained anisotropic conductive sheet is increased. The use amount of such an inorganic filler is not particularly limited, but using a large amount is not preferable because the orientation of the conductive particles cannot be sufficiently achieved by the magnetic field. The viscosity of the sheet molding material is preferably in the range of 10,000 to 1,000,000 cp at a temperature of 25 ° C.

By arranging and operating the electromagnets on the upper and lower molds of the anisotropic conductive sheet molding die, the thickness of the sheet molding material layer 1A is interposed via the substrate 10 and the magnetic portion 25. A parallel magnetic field acts in the direction. As a result, in the sheet molding material layer 1A, the conductive particles dispersed in the sheet molding material layer 1A are positioned between the upper magnetic body portion 25 and the lower magnetic body portion 25, that is, Conductive portion forming portion 2A in sheet forming material layer 1A
And more preferably oriented in the thickness direction of the sheet forming material layer 1A. Then, in this state, the sheet forming material layer 1A is subjected to a hardening treatment, so that the upper magnetic member 25 and the lower magnetic member 25 as shown in FIG.
And a conductive portion 2 densely filled with conductive particles and an insulating portion 3 having no or almost no conductive particles are formed. Then, the anisotropic conductive sheet 1 having the configuration shown in FIG. 16 is obtained by releasing the anisotropic conductive sheet molding die.

In the above, the curing treatment of the sheet molding material layer 1A can be performed while the parallel magnetic field is applied, but can also be performed after the application of the parallel magnetic field is stopped. The strength of the parallel magnetic field applied to the sheet forming material layer 1A is preferably in a range of 200 to 10000 gauss on average. As a means for applying a parallel magnetic field, a permanent magnet can be used instead of an electromagnet.
As such a permanent magnet, Alnico (registered trademark) (Fe-A
1-Ni-Co alloy), ferrite, and the like. In the conductive portion 2 thus obtained, since the conductive particles are oriented so as to be arranged in the thickness direction of the anisotropic conductive sheet 1, good conductivity can be obtained even if the ratio of the conductive particles is small.

The curing treatment of the sheet molding material layer 1A is appropriately selected depending on the material to be used, but is usually carried out by a heating treatment. In the case where the curing treatment of the sheet molding material layer 1A is performed by heating, the specific heating temperature and heating time are determined by the type of the material for the polymer substance constituting the sheet molding material layer 1A and the time required for moving the conductive particles. It is appropriately selected in consideration of such factors.

According to such a method, the strength of the magnetic field formed between the upper magnetic member 25 and the lower magnetic member 25 is reduced by the upper non-magnetic layer 20 and the lower magnetic member 25. Since the strength of the magnetic field formed between the mold 20 and the non-magnetic material layer 20 is extremely high, the conductive portion forming portion 2A in the sheet molding material layer 1A has a portion other than the conductive portion forming portion 2A. A magnetic field that is sufficiently larger than the part,
As a result, even if the pitch of the conductive portions 2 of the anisotropic conductive sheet 1 to be formed is small and has a complicated pattern, the anisotropic conductive sheet 1 having a required insulating property between adjacent conductive portions 2 is formed. Can be manufactured.

The present invention is not limited to the above embodiment, and various changes can be made. (1) The shape of the magnetic particles is not limited to a spherical one as long as they can be filled in the through holes of the non-magnetic layer.
For example, it may have a rod shape, a column shape, or another shape, or may be a mixture of magnetic particles having different shapes or particle diameters. Specifically, as shown in FIG. 17, the magnetic particles 26 having different shapes or particle diameters are used.
By using, the ratio of the magnetic particles 26 occupying the magnetic portion forming space in the through holes 21 of the nonmagnetic layer 20 can be increased. As shown in FIG. 18, a plurality of magnetic particles 26 having a cross-sectional shape matching the cross-sectional shape of the through-hole of the nonmagnetic layer are stacked in the magnetic portion forming space in the through-hole of the nonmagnetic layer. By filling and filling
Alternatively, as shown in FIG. 19, the magnetic particles 26 having a shape conforming to the shape of the magnetic portion forming space in the through-hole of the non-magnetic layer are formed by forming the magnetic particles 26 in the through-hole of the non-magnetic layer. By filling the space, the ratio of the magnetic particles 26 occupying the magnetic portion forming space in the through hole 21 of the nonmagnetic layer 20 can be further increased.

(2) The cavity forming layer is not essential in the present invention. For example, when forming an anisotropic conductive sheet having a flat surface, the cavity forming layer is unnecessary. (3) As a method for forming the nonmagnetic layer 20, for example, a method of forming a layer made of a thermosetting resin on the substrate 10 and irradiating the layer with a laser to form the through holes 21 is adopted. Can also.

[0062]

EXAMPLES The present invention will now be described by way of specific examples, which should not be construed as limiting the invention thereto.

Example 1 (1) Formation of Nonmagnetic Layer: Dimension 150 mm × 200 mm
A substrate made of soft iron SS400 having a size of 6 mm was prepared, and a 50 μm-thick dry film resist was laminated on the surface of the substrate to form a photoresist layer. On the surface of the photoresist layer, a mask on which a radiation shielding portion is formed is positioned and arranged in accordance with a pattern corresponding to a through hole of a nonmagnetic layer to be formed, and a high-pressure mercury lamp is applied to the photoresist layer. 8 as light source
After performing radiation irradiation treatment with an exposure amount of 0 mJ / cm ² ,
Spray development was performed for 1 minute using a 1% aqueous sodium carbonate solution as a developer. By performing the above steps three times in total, a nonmagnetic layer having a thickness of 150 μm was formed on the substrate. The through-hole of this nonmagnetic layer has a size of 80 μm ×
It had a rectangular cross section of 320 μm and a pitch of 160 μm.

(2) Formation of magnetic material portion: Substantially spherical magnetic particles (made of iron, having an average particle size of 40 μm) are provided in the through holes of the nonmagnetic material layer.
m), and a liquid acrylic thermosetting resin "NPR-60" (Nippon Polytech Co., Ltd.)
By a screen printer.
After forming a lid material forming material layer and performing a heat treatment at 160 ° C. for 120 minutes, the wrapping device “Hipratez EJ
-380 "(manufactured by Nippon Engis) and diamond abrasive compound (manufactured by Nippon Engis) as an abrasive
The surface of the obtained cured resin layer was polished under the conditions of 80 rpm for 30 minutes to form a lid material in each of the through holes of the nonmagnetic layer. The thickness of this lid is 1
5 μm (the thickness of the space between the substrate and the lid material is 150 μm)
m), the ratio of the magnetic particles filled in the magnetic part forming space to the magnetic part forming space was 65% by volume on average.

(3) Formation of a cavity forming layer: A photoresist layer was formed by laminating a dry film resist having a thickness of 50 μm on the surfaces of the nonmagnetic layer and the cover material. On the surface of this photoresist layer, a mask on which a radiation shielding part is formed is positioned and arranged in accordance with a pattern corresponding to the hole of the cavity forming layer to be formed, and a high-pressure mercury lamp is used as a light source for the photoresist layer. After performing a radiation irradiation treatment at an exposure amount of 80 mJ / cm ² , a cavity forming layer was formed by performing spray development for 1 minute using a 1% aqueous solution of sodium hydrogen carbonate as a developing solution. A lower mold having the configuration shown was manufactured.

By forming the non-magnetic layer, forming the magnetic portion, and forming the cavity layer in the same manner as in the above-mentioned methods (1) to (3), the lower mold and the pair are formed. An upper mold was manufactured, and a desired mold for forming an anisotropic conductive sheet was manufactured.

Example 2 (1) Formation of Nonmagnetic Layer: Dimension 150 mm × 200 mm
A substrate made of soft iron SS400 having a size of 6 mm was prepared, and a 40 μm-thick dry film resist was laminated on the surface of the substrate to form a photoresist layer. On the surface of the photoresist layer, a mask on which a radiation shielding portion is formed is positioned and arranged in accordance with a pattern corresponding to a through hole of a nonmagnetic layer to be formed, and a high-pressure mercury lamp is applied to the photoresist layer. 3 as a light source
After performing a radiation irradiation treatment at an exposure amount of 00 mJ / cm ² , spray development was performed for 1 minute using a 1% aqueous sodium hydrogen carbonate solution as a developing solution. The above process is 3 in total
This was repeated twice to form a non-magnetic layer having a thickness of 120 μm on the substrate. The through-hole of this non-magnetic layer has a size of 8
0μm × 320μm rectangular cross section, 160μ pitch
m.

(2) Formation of magnetic material portion: Substantially spherical magnetic particles (made of iron, having an average particle size of 60 μm) were formed in the through-holes of the non-magnetic material layer.
After filling m), an acrylic photoresist is applied by a screen printing machine to form a photoresist layer, and a mask on which a radiation shielding portion is formed is aligned in accordance with a pattern corresponding to a temporary lid to be formed. After irradiating the photoresist layer with a high-pressure mercury lamp as a light source and irradiating it with an exposure amount of 300 mJ / cm ² , spray development is performed for 1 minute using a 1% aqueous sodium hydrogen carbonate solution as a developing solution. As a result, a temporary lid as shown in FIG. 9 was formed on the nonmagnetic layer. The dimensions of the temporary lid were 100 μm × 260 μm × 15 μm, and the width of the gap between the opening edge of the through hole of the non-magnetic layer and the peripheral edge of the temporary lid was 30 μm. Next, the surface of the substrate on which the nonmagnetic layer is not formed is masked with a resist tape, leaving a portion to be used as a lead electrode portion for plating.
Then, in a nickel plating solution containing nickel sulfamate as a main component, an electrolytic plating process is performed for 2 hours at a temperature of 60 ° C. and a current value of 0.5 A / dm ² , so that the through-holes in the nonmagnetic layer are formed. A magnetic phase was formed around the filled magnetic particles. Then, a liquid acrylic thermosetting resin is applied on the non-magnetic material layer by a screen printer to form a lid material forming material layer.
After the heat treatment under the condition of 20 minutes, the hardening obtained by the lapping apparatus “Hiprates EJ-380” using the diamond abrasive compound (manufactured by Nippon Engis Co., Ltd.) as the abrasive at 80 rpm for 30 minutes. By polishing the surface of the resin layer, a lid material was formed in each of the through holes of the nonmagnetic layer. The thickness of this lid material is 20 μm
(The thickness of the magnetic part forming space is 120 μm and the aspect ratio is 1.5), and the ratio of the magnetic particles and the magnetic phase filled in the magnetic part forming space to the magnetic part forming space is an average. It was 85% by volume, and the volume ratio between the magnetic particles and the magnetic phase was 65:20 on average.

(3) Formation of cavity forming layer: A photoresist layer was formed by laminating a dry film resist having a thickness of 50 μm on the surfaces of the nonmagnetic layer and the cover material. On the surface of this photoresist layer, a mask on which a radiation shielding part is formed is positioned and arranged in accordance with a pattern corresponding to the hole of the cavity forming layer to be formed, and a high-pressure mercury lamp is used as a light source for the photoresist layer. After performing a radiation irradiation treatment at an exposure amount of 80 mJ / cm ² , a cavity forming layer was formed by performing spray development for 1 minute using a 1% aqueous solution of sodium hydrogen carbonate as a developing solution. A lower mold having the configuration shown was manufactured.

The formation of the nonmagnetic layer, the formation of the magnetic part, and the formation of the cavity layer are carried out in the same manner as in the above methods (1) to (3), whereby the lower mold and the pair are formed. An upper mold was manufactured, and a desired mold for forming an anisotropic conductive sheet was manufactured.

<Comparative Example 1> dimensions 150 mm x 200 mm
A substrate made of soft iron SS400 having a size of 6 mm was prepared, and a 50 μm-thick dry film resist was laminated on the surface of the substrate to form a photoresist layer. On the surface of the photoresist layer, a mask on which a radiation shielding portion is formed is positioned and arranged in accordance with a pattern corresponding to a through hole of a nonmagnetic layer to be formed, and a high-pressure mercury lamp is applied to the photoresist layer. 8 as light source
After performing radiation irradiation treatment with an exposure amount of 0 mJ / cm ² ,
1% aqueous sodium hydrogen carbonate solution
Spray development for minutes. By performing the above steps twice in total, a nonmagnetic layer having a thickness of 100 μm was formed on the substrate. The size of the through-hole of this non-magnetic layer is 80 μm.
It had a rectangular cross section of m × 320 μm and a pitch of 160 μm.

The surface of the substrate on which the non-magnetic layer is not formed is masked with a resist tape except for a portion to be used as a plating lead wire electrode portion, and then is plated in a nickel plating solution mainly containing nickel sulfamate. ,
Electroplating is performed for 3 hours at a temperature of 45 ° C. and a current value of 2 A / dm ² to form a nickel deposit in the through-hole of the non-magnetic layer, and a wrapping device “HIPLETS EJ-380” Using diamond abrasive compound (made by Nippon Engis Co., Ltd.) as an abrasive
By polishing at 0 rpm for 30 minutes,
A magnetic part having the same thickness as the non-magnetic layer was formed.
The aspect ratio of this magnetic body is 1.25.

A photoresist layer was formed by laminating a dry film resist having a thickness of 50 μm on the surfaces of the nonmagnetic layer and the magnetic portion. On the surface of this photoresist layer, a mask on which a radiation shielding part is formed is positioned and arranged in accordance with a pattern corresponding to the hole of the cavity forming layer to be formed, and a high-pressure mercury lamp is used as a light source for the photoresist layer. After performing a radiation irradiation treatment at an exposure amount of 80 mJ / cm ² , 1%
By performing spray development for 1 minute using an aqueous solution of sodium hydrogencarbonate, a cavity forming layer was formed to produce a lower mold. In addition, by forming a non-magnetic layer, forming a magnetic portion, and forming a cavity layer in the same manner as described above, an upper mold that is to be paired with the lower mold described above is manufactured, and the desired difference is obtained. A mold for forming an electroconductive sheet was manufactured.

[Production of Anisotropically Conductive Sheet] Examples 1 and 2
Using the mold for producing an anisotropic conductive sheet obtained in Comparative Example 1, an anisotropic conductive sheet was produced as follows. The fluorine-based release agent “DAIFREE A441” (manufactured by Daikin Industries, Ltd.) was spray-coated on the molding surfaces of the upper mold and the lower mold. Next, a polyimide sheet having a thickness of 100 μm is used as a frame-shaped spacer, and a sheet molding material in which nickel particles having an average particle diameter of 40 μm are contained in a room-temperature-curable silicone rubber in a ratio of 25% by volume is placed in a mold. Injected. An electromagnet is arranged on the upper surface of the upper die and the lower surface of the lower die in this mold, and a heat treatment is performed at 120 ° C. for 30 minutes while applying a magnetic field of 3000 gauss by the electromagnet. An anisotropic conductive sheet having a protruding conductive portion was manufactured. Each of the obtained anisotropic conductive sheets had an insulating portion thickness of 150 μm.
m, the pitch of the conductive parts is 160 μm, and the protrusion height of the surface is 5
It was 0 μm.

[Evaluation of Anisotropic Conductive Sheet] Each of the obtained anisotropic conductive sheets was evaluated as follows. (1) Conductivity of conductive part: As shown in FIG. 20, a resistance measuring device 40 ("Milliohm Hi Tester" manufactured by Hioki Electric Co., Ltd.)
The electrical resistance of the conductive part 2 of the anisotropic conductive sheet 1 was measured using a resistance measuring device composed of the probe pins 41, the short-circuiting plate 42, and the lead wires 43. (2) Insulation between conductive parts: As shown in FIG. 21, a resistance measuring device composed of a resistance measuring device 40 (“Milliohm High Tester” manufactured by Hioki Electric Co., Ltd.), a pair of probe pins 41 and lead wires 43 is used. Using an anisotropic conductive sheet 1
Was measured for the electrical resistance between adjacent conductive parts 2. The results are shown in Table 1.

[0076]

[Table 1]

As is clear from the results in Table 1, Example 1
According to the molds for forming an anisotropic conductive sheet according to (2), while the pitch of the conductive portion is small, the conductive portion has good conductivity and has a required insulation property between adjacent conductive portions. It was confirmed that an anisotropic conductive sheet having the following formula was obtained.

[0078]

According to the mold of the present invention, the magnetic part is mainly composed of magnetic particles, and there is no limitation on the type of magnetic material forming the magnetic particles. A magnetic material having a high magnetization intensity can be used as the magnetic material constituting the portion. Moreover, the magnetic particles are fixed by filling the space between the substrate and the cover material in the through-holes of the non-magnetic layer, and are used to fix the magnetic particles in forming the magnetic part. Since it is not necessary to use a binder made of a non-magnetic material, a magnetic part having a high density of the magnetic material can be formed. Therefore, a magnetic field having a sufficient intensity distribution can be applied to the sheet forming material layer, and an anisotropic conductive sheet having a conductive pattern with a small pitch and a complicated pattern can be formed. Further, by forming a magnetic phase around the magnetic particles, it is possible to form a magnetic portion having a very high density of the magnetic material, and thus have a more sufficient strength distribution with respect to the sheet molding material layer. A magnetic field can be applied.

According to the method for manufacturing a mold of the present invention, a magnetic field having a sufficient intensity distribution can be formed on a sheet molding material layer, and a conductive pattern having a small pitch and a complicated pattern is provided. In addition, it is possible to manufacture a mold capable of forming an anisotropic conductive sheet having a required insulating property between conductive portions. According to the method of manufacturing an anisotropic conductive sheet of the present invention, even if the pitch of the conductive portions is small and has a complicated pattern, the anisotropic conductive sheet having a required insulating property between adjacent conductive portions can be formed. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a configuration of a main part of a lower mold in an example of a mold for forming an anisotropic conductive sheet according to the present invention.

FIG. 2 is an explanatory sectional view showing a state in which a non-magnetic layer is formed on a substrate.

FIG. 3 is an explanatory cross-sectional view showing a state where magnetic particles are filled in through holes of a nonmagnetic layer.

FIG. 4 is an explanatory cross-sectional view showing a state in which a lid material forming material layer is formed on a non-magnetic material layer.

FIG. 5 is an explanatory cross-sectional view showing a state in which a lid member is formed in an opening of a through hole in a nonmagnetic layer.

FIG. 6 is an explanatory cross-sectional view showing a state where a photoresist layer is formed on the surfaces of a nonmagnetic layer and a lid member.

FIG. 7 is an explanatory cross-sectional view showing a configuration of a main part of a lower mold in another example of the anisotropic conductive sheet molding die according to the present invention.

FIG. 8 is an explanatory cross-sectional view showing a state where a temporary lid is formed on a nonmagnetic layer.

FIG. 9 is a plan view showing a state where a temporary lid is formed on a non-magnetic layer.

FIG. 10 is an explanatory cross-sectional view showing a state in which a magnetic phase is formed around magnetic particles in a through hole of a nonmagnetic layer.

FIG. 11 is an explanatory cross-sectional view showing a state where a lid material forming material layer is formed on a non-magnetic material layer.

FIG. 12 is an explanatory cross-sectional view showing a state in which a cover material is formed in an opening of a through hole in a nonmagnetic layer.

FIG. 13 is an explanatory cross-sectional view showing a state where a photoresist layer is formed on the surfaces of a nonmagnetic layer and a lid member.

FIG. 14 is an explanatory sectional view showing a state in which a molding material layer is formed in a mold for molding an anisotropic conductive sheet.

FIG. 15 is an explanatory cross-sectional view showing a state in which a magnetic field having an intensity distribution is applied to a molding material layer in a mold for molding an anisotropic conductive sheet.

FIG. 16 is an explanatory cross-sectional view illustrating a configuration of an example of an anisotropic conductive sheet obtained by a manufacturing method of the present invention.

FIG. 17 is an explanatory sectional view showing a configuration of a main part of a lower die in still another example of the anisotropic conductive sheet forming die according to the present invention.

FIG. 18 is an explanatory cross-sectional view showing a configuration of a main part of a lower die in still another example of the anisotropic conductive sheet forming die according to the present invention.

FIG. 19 is an explanatory sectional view showing a configuration of a main part of a lower die in still another example of the anisotropic conductive sheet forming die according to the present invention.

FIG. 20 is an explanatory view showing an apparatus for measuring the resistance of a conductive portion in an anisotropic conductive sheet manufactured in an example.

FIG. 21 is an explanatory view showing an apparatus for measuring a resistance between adjacent conductive portions in an anisotropic conductive sheet manufactured in an example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 anisotropic conductive sheet 1A sheet forming material layer 2 conductive portion 2A conductive portion forming portion 3 insulating portion 10 substrate 20 nonmagnetic layer 21 through hole 22 lid 22A lid material forming layer 23 temporary lid 25 magnetic portion 26 magnetic Body particles 27 Magnetic phase 30 Cavity forming layer 30A Photoresist layer 31 Hole 40 Resistance measuring instrument 41 Probe pin 42 Short circuit board 43 Lead wire

Claims (10)

[Claims] 1. A mold comprising a plurality of magnetic members formed on a substrate made of a magnetic material and spaced apart from each other, the non-magnetic material having a plurality of through holes formed on the substrate. And a cover material provided so as to close the through-hole of the non-magnetic material layer. The magnetic material portion is provided between the substrate and the cover material in the through-hole of the non-magnetic material layer. A mold comprising magnetic particles filled in a space. 2. The gold according to claim 1, wherein the ratio of the magnetic particles occupying the space between the substrate and the cover material in the through hole of the nonmagnetic layer is 30% by volume or more. Type. 3. A mold comprising a plurality of magnetic members formed on a substrate made of a magnetic material and spaced apart from each other, the non-magnetic material having a plurality of through holes formed on the substrate. And a cover material provided so as to close the through-hole of the non-magnetic material layer. The magnetic material portion is provided between the substrate and the cover material in the through-hole of the non-magnetic material layer. A mold comprising magnetic particles filled in a space and a magnetic phase formed around the magnetic particles. 4. The mold according to claim 1, which is used for forming an anisotropic conductive sheet. 5. The mold according to claim 1, wherein the nonmagnetic layer is made of a resin material cured by radiation. 6. The mold according to claim 1, wherein the lid member is made of a resin material cured by heat or radiation. 7. The method for manufacturing a mold according to claim 1, wherein a non-magnetic layer having a plurality of through holes is formed on a substrate made of a magnetic substance, and the non-magnetic layer is formed through the non-magnetic layer. A method for manufacturing a mold, comprising a step of filling magnetic particles in a hole and forming a cover material in the nonmagnetic layer so as to cover the through hole. 8. The method for manufacturing a mold according to claim 3, wherein a non-magnetic layer having a plurality of through holes is formed on a substrate made of a magnetic substance, The magnetic particles are filled in the holes, and a magnetic metal plating process is performed on the magnetic particles filled in the through holes of the non-magnetic layer to form a magnetic material phase around the magnetic particles. And a step of forming a lid material on the nonmagnetic layer so as to close the through hole. 9. After filling magnetic particles in the through-holes of the non-magnetic layer, a temporary cover is provided in the non-magnetic layer so that the magnetic particles do not leak out of the through-holes and the plating solution passes therethrough. 9. The method according to claim 8, wherein a magnetic metal is plated on the magnetic particles filled in the through holes of the nonmagnetic layer in a plating solution. 10. A method of manufacturing an anisotropic conductive sheet comprising a plurality of conductive portions extending in a thickness direction arranged in a state in which the conductive portions are insulated from each other by an insulating portion. Using a mold described in any of (1) to (5), a mold is filled with a sheet molding material containing conductive particles exhibiting magnetism in a material for an elastic polymer which is cured to become an elastic polymer material. A method for producing an anisotropic conductive sheet, comprising a step of applying a magnetic field having an intensity distribution to a molding material via the mold and curing the sheet molding material.