JP3146682B2 - Mold for producing anisotropic conductive sheet, method for producing the same, and anisotropic conductive sheet - Google Patents

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. For manufacturing an anisotropic conductive sheet used for the method, and a method for manufacturing the mold,
And an anisotropic conductive sheet .

[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 pressed anisotropic conductive sheet, conductive particles are relatively densely dispersed in the conductive portion,
In addition, there is known a structure in which such a conductive portion is formed in an insulating elastomer so as to protrude from the surface of the insulating portion.

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. In a state where a gap is formed between the upper mold forming surface of the mold and the upper surface of the molding material layer, a magnetic field is applied to the molding material layer in the thickness direction of the layer to reduce the magnetic force of the magnetic field. There is known a method in which a molding material is caused to flow while moving conductive particles by utilizing the characteristics of a mold by the action to change the outer shape of the upper surface of the molding material and to cure the molding in that state.

The dies used in the above-described method for producing an anisotropic conductive sheet are each composed of a pair of upper and lower dies corresponding to each other, each of which has a substantially flat plate shape. A structure in which the upper mold and the lower mold are configured to be attachable to the electromagnet, or are configured integrally with the electromagnet, so that the layer of the molding material can be heated and cured while applying a magnetic field to the layer of the molding material. belongs to. In addition, in order to form a protrusion that becomes a conductive portion at an appropriate position by applying a magnetic field to the layer of the molding material, the upper mold or the upper mold and the lower mold of the mold are made of a ferromagnetic material such as iron or nickel. A ferromagnetic part made of iron, nickel, and the like, and a non-magnetic part made of a non-magnetic metal, such as copper, are arranged in a mosaic pattern on a substrate made of iron, nickel, or the like for generating an intensity distribution in the magnetic field in the mold. (Hereinafter referred to as “mosaic layer”), and the molding surfaces of the upper and lower molds of the mold are flat or have a height higher than that of the projecting portion of the anisotropic conductive sheet. It has slight irregularities.

In these molds, a magnetic field having an intensity distribution can be formed by an electromagnet on the entire molding surface on which the layer of the molding material is formed. The arrangement, shape, and the like of the ferromagnetic material portion and the nonmagnetic material portion in the mosaic layer are determined based on 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 shape of the ferromagnetic portion is adapted to the cross-sectional shape of the conductive portion.

The mold having the mosaic layer as described above is
For example, a portion to constitute a non-magnetic material portion is removed from a ferromagnetic plate by a method such as cutting or etching, and a non-magnetic material is formed by pouring a resin or plating copper into the formed removed portion. To form a mosaic layer.

[0008]

However, when a mosaic layer is formed by an etching method in the manufacture of a mold as described above, side etching occurs. There is a problem that it is considerably difficult to form a mosaic layer in which the center-to-center distance of the ferromagnetic portion is small, for example, 0.3 mm or less. Further, when the mosaic layer is formed by a cutting method, it is possible to form a mosaic layer having a small center-to-center distance between adjacent ferromagnetic portions, for example, about 0.1 mm as compared with the etching method. However, in order to form a mosaic layer in which the arrangement of the ferromagnetic material portion and the non-magnetic material portion is complicated, it takes too much work and time, and therefore, the obtained mold has a high manufacturing cost. There's a problem. Further, there is a problem that it is difficult to form a mosaic layer in which the arrangement of the ferromagnetic material portion and the nonmagnetic material portion is extremely complicated.

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 easily manufacture a mold capable of manufacturing an anisotropic conductive sheet having a pattern with a small distance. Therefore, an object of the present invention is to form a mosaic layer in which the arrangement of the ferromagnetic material portion and the non-magnetic material portion is complicated and miniaturized easily, and a mold capable of manufacturing a desired anisotropic conductive sheet , And the mold
Another object of the present invention is to provide a manufacturing method and an anisotropic conductive sheet .

[0010]

According to the present invention, there is provided a mold for producing an anisotropic conductive sheet, in which a magnetic portion and a non-magnetic portion made of metal are arranged along a surface of a substrate made of magnetic metal.
Which is constituted by the non-magnetic portion is photolithography
According to the method of ィ, formed of a heat-resistant polymer material cured by radiation , the magnetic material portion is plated
Characterized in that it is formed by. Anisotropy of the present invention
The method for manufacturing the conductive sheet manufacturing mold is made of a magnetic metal.
Along with the surface of the substrate,
Made of anisotropic conductive sheet composed of sexual parts arranged
A method for manufacturing a molding die, the method comprising:
And by photolithography,
Non-magnetic part made of heat-resistant polymer material cured by heating
Forming a non-magnetic material portion on the surface of the substrate.
Polish the plated and plated parts to the parts that are not
To form a magnetic part with a flat surface
It is characterized by. Also, for producing the anisotropic conductive sheet of the present invention
The manufacturing method of the mold is based on the surface of
The magnetic and non-magnetic parts made of metal are arranged
For manufacturing anisotropically conductive sheet-producing mold constituted by
And a photolithography along the surface of the substrate.
The heat resistance cured by radiation
Forming a nonmagnetic portion of the first layer made of a polymer material,
Non-magnetic part on the surface of the substrate is not formed
By plating the part and polishing the plated part
Forming a magnetic material portion having a flat surface,
Forming a non-magnetic portion of the second layer on the non-magnetic portion of the layer
It is characterized by that. The anisotropic conductive sheet of the present invention
Manufactured using the mold for manufacturing an anisotropic conductive sheet described above.
And features.

[0011]

According to the mold having the above structure , the non-magnetic portion is formed by photolithography.
Later, since the ferromagnetic portion is formed by plating , the mosaic layer can be formed very easily and reliably even if the ferromagnetic portion and the nonmagnetic portion are arranged in a complicated and fine pattern. As a result, a desired anisotropic conductive sheet can be manufactured.

[0012]

FIG. 4 is an explanatory view showing a specific structure of a mold for producing an anisotropic conductive sheet according to the present invention. In this figure,
Reference numeral 1 denotes a substrate made of a magnetic metal, on which a non-magnetic portion 2 and a ferromagnetic portion 3 forming a mosaic layer are provided. The nonmagnetic portion 2 has a first nonmagnetic layer 2 a having the same thickness as the ferromagnetic portion 3.
And a second non-magnetic layer 2b provided on the first non-magnetic layer 2a.
The second nonmagnetic layer 2b is made of a polymer material cured by radiation.

The mold having the above-described structure is manufactured by the following method. (1) Formation of Non-Magnetic Layer 2a As shown in FIG. 1, a first non-magnetic layer 2a is formed on a substrate 1 made of a magnetic metal while leaving a portion where a ferromagnetic portion is to be formed. Is done. As a method of forming the nonmagnetic layer 2a, a photolithography method can be used. In this case, a method of laminating a later-described photoresist on the substrate 1, screen printing, spin coating, applicator coating, or the like is used. Coating, and on top of that,
As shown in FIG. 5, a non-magnetic material layer 2a is formed by applying a radiation over a film mask 6 having a radiation shielding part 5 having a pattern corresponding to the ferromagnetic material part 3, and then developing the radiation. can do.

The substrate 1 is made of, for example, a ferromagnetic metal such as iron, iron-nickel alloy, iron-cobalt alloy, nickel, and cobalt. The substrate 1 has a thickness of 0.1 mm
It is preferable that the surface is smooth, chemically degreased, and mechanically polished. The first nonmagnetic layer 2a is made of a polymer material cured by radiation, and is made of, for example, a photo resist such as an acrylic dry film resist, an epoxy liquid resist, or a polyimide liquid resist. Resist. It is preferable that the thickness of the first nonmagnetic layer 2a is 10 μm or more.

(2) Formation of Ferromagnetic Portion As shown in FIG. 2, a ferromagnetic portion 3 is formed on a portion of the substrate 1 where the first 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 forming the ferromagnetic part 3,
By polishing the surface of the ferromagnetic material portion 3, the surface is 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. It is preferable that the thickness of the ferromagnetic portion 3 is 10 μm or more. Ferromagnetic part 3
When the thickness is less than 10 μm, it is difficult to apply a magnetic field having a sufficient intensity distribution when manufacturing the anisotropic conductive sheet. As a result, in the process shown in FIG. Since it is difficult to concentrate the conductive particles in the molding material at a high density in a portion sandwiched between the ferromagnetic portions 3 in the molding space, that is, a portion where the conductive portion is to be formed, the obtained sheet is good. It does not have any anisotropic conductivity.

(3) Formation of Second Non-Magnetic Layer 2b The above-described first non-magnetic layer 2b is added to the state shown in FIG.
By forming the second non-magnetic material layer 2b on the first non-magnetic material layer 2a by performing the same processing as the formation of the first non-magnetic material layer 2a, FIG.
As shown in FIG. 1, a mosaic layer is formed by the nonmagnetic portion 2 composed of the first nonmagnetic layer 2a and the second nonmagnetic layer 2b, and the ferromagnetic portion 3.

The material constituting the second non-magnetic layer 2b can be selected from the same range as that of the first non-magnetic layer 2a, and is made of the same material as the first non-magnetic layer 2a. Although it can be used, a type different from the first nonmagnetic layer 2a can be used as long as the connection between the layers is maintained. The thickness of the second nonmagnetic layer 2b is
It is designed based on the anisotropic conductive sheet to be manufactured, but is 10 μm to 200 μm, preferably 20 μm to 2 μm.
It is designed within the range of 00 μm.

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 formed. By manufacturing, the mosaic layer can be easily formed. That is, since the non-magnetic portion 2 is formed by being divided into the first non-magnetic layer 2a and the second non-magnetic layer 2b, the first non-magnetic layer 2a or the second non-magnetic layer 2a is formed. Since the resolution of photolithography at the time of forming the magnetic layer 2b is surely better than the resolution of photolithography at the time of forming the nonmagnetic portion 2 in one layer, the film A mosaic layer having a pattern with high fidelity to the mask 6 can be formed. Further, as shown in FIG.
By making the thickness of the ferromagnetic portion 3 larger than the thickness of the ferromagnetic portion 3, it is possible to reliably manufacture an anisotropic conductive sheet having the conductive portion 16 protruding from the insulating portion 17 as shown in FIG. it can.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto. [Mold manufacturing example] 10 mm long, 15 mm wide, 1.6 m thick
An epoxy liquid resist ("NPR60-5P", manufactured by Japan Polytech Co., Ltd.) was applied to a substrate made of a soft iron plate with a thickness of 120 m using a screen printing machine through a 120-mesh screen plate and dried. The thickness of the coating layer after drying is 70 μ
m. On this surface, a film mask having a pattern as shown in FIG. 5 is positioned and installed, and is contact-exposed at a light exposure of 200 mJ / cm ² using an ultra-high pressure mercury lamp as a light source. A non-magnetic layer was formed as shown in FIG. 1 by spray development for 2 minutes using a solution temperature of 30 ° C.).

The surface of the substrate on which the nonmagnetic layer is not formed is masked with a resist tape except for a portion to be used as a lead electrode for plating, and then, in a nickel plating bath containing nickel sulfamate as a main component, Temperature 4
By performing plating treatment at 5 ° C. and a current value of 2 A / dm ² for 3 hours, a ferromagnetic material portion was formed as shown in FIG. Then, a diamond abrasive compound (Nippon Eggins Co., Ltd.) was used as an abrasive by a lapping device ("Hi-Plates EJ-380", Nippon Eggins Co., Ltd.)
The surface was polished at 80 rpm for 30 minutes using
After the surface was flattened as shown in FIG.

On the surface on which the nonmagnetic layer and the ferromagnetic portion are formed, an epoxy liquid resist ("NPR60-5P", manufactured by Japan Polytech Co., Ltd.) is applied by a screen printing machine.
It was applied through a 0 mesh screen plate and dried.
The thickness of the coating layer after drying was 30 μm. On this surface, the same film mask as the previous one was positioned and installed, and it was adhered by an ultraviolet irradiation device for printed circuit boards ("Phoenix-3000" manufactured by Oak Manufacturing Co., Ltd.) at an exposure amount of 245 mJ / cm ² using an ultra-high pressure mercury lamp as a light source. After exposure, a non-magnetic layer was formed by spray development using a 1% aqueous solution of sodium carbonate (solution temperature 30 ° C.) for 2 minutes as a developing solution to obtain a lower mold of a mold as shown in FIG. Was.

A non-magnetic material portion of the lower die of the mold thus obtained is applied to a belt conveyor type ultraviolet irradiator (manufactured by Oak Works) using a metal halide as a light source.
After irradiating with ultraviolet light at an exposure amount of 500 mJ / cm ² ,
The non-magnetic material portion was post-cured by heating for 30 minutes in a hot air dryer at 50 ° C.

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

[Production Example of Anisotropic Conductive Sheet] A fluorine-based release agent (“Daifree A44” manufactured by Daikin Industries, Ltd.) is applied to the molding surfaces of the upper and lower dies obtained by the die production example.
1)). Next, as shown in FIG. 6, a polyimide sheet 7 having a thickness of 70 μm was used as a frame spacer, and nickel particles having an average particle diameter of 40 μm were 25
A molding material 8 composed of a room-temperature-curable silicone rubber composition mixed at a ratio of volume% is injected, the upper molds are aligned and overlapped, and as shown in FIG. After heating at 120 ° C. for 30 minutes in a state where a magnetic field of 3000 Gauss is applied by the heating device 10 having the above structure, the mold is removed, and the outer periphery is integrated with the polyimide sheet 7 as shown in FIG. An anisotropic conductive sheet 11 having a conductive portion 16 protruding from 17 was obtained. The thickness of this sheet is 190 μm, and the distance between the centers of the conductive parts is 250 μm.
μm, and the projection height of the surface was 30 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. 1, a resistance measuring instrument 12 (“Milliohm Hi Tester” manufactured by Hioki Electric Co., Ltd.), a short-circuit plate 13, and a probe pin 1
4. When the resistance of each conductive part 16 was measured using a resistance measuring device composed of the lead wire 15, complete conduction was obtained in all the conductive parts, and the resistance value was 15 mΩ to 33 mΩ.
It was in the range of mΩ and very low. Also,
As shown in FIG. 10, when the short-circuit resistance between the adjacent conductive portions was measured, the resistance values were all 2 MΩ or more, indicating good insulation resistance.

[0027]

As described above in detail, in the mold for manufacturing an anisotropic conductive sheet according to the present invention, the nonmagnetic portion
Cured by radiation by lithographic techniques
Ferromagnetic material is formed by
Therefore , the mosaic layer can be easily formed even if the ferromagnetic portion and the nonmagnetic portion are arranged in a complicated and fine pattern. 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 view showing a state in which a non-magnetic 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 nonmagnetic layer and a ferromagnetic portion are formed in an example.

FIG. 4 is an explanatory diagram showing a specific configuration of a mold according to the embodiment.

FIG. 5 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. 6 is an explanatory view showing a state in which an anisotropic conductive sheet material is injected into a mold in Examples.

FIG. 7 is an explanatory diagram illustrating a configuration of an anisotropic conductive sheet manufacturing apparatus in an example.

FIG. 8 is an explanatory diagram of an anisotropic conductive sheet manufactured in an example.

FIG. 9 is an explanatory view showing the configuration of an apparatus for measuring the resistance of the conductive portion of the anisotropic conductive sheet produced in the example.

FIG. 10 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]

DESCRIPTION OF SYMBOLS 1 Substrate 2a 1st nonmagnetic layer 2b 2nd nonmagnetic layer 2 Nonmagnetic part 3 Ferromagnetic part 4 Radiation transmitting part 5 Radiation shielding part 6 Film mask 7 Polyimide sheet 8 Molding material 9 Parallel magnetic field pole plate REFERENCE SIGNS LIST 10 heating device 11 anisotropic conductive sheet 12 resistance measuring device 13 short-circuit plate 14 probe pin 15 lead wire 16 conductive part 17 insulating part

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Kiyoshi Kimura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-4-151889 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 13/00 H01B 5/00-5/16

Claims (6)

(57) [Claims] Along a surface of a substrate made of a magnetic metal,
A magnetic part and a non-magnetic part made of metal are arranged and arranged, and the non-magnetic part is formed by photolithography.
Ri, heat resistance of the polymeric substance cured by radiation
The magnetic material portion is formed by plating.
A mold for producing an anisotropic conductive sheet, comprising: 2. The surface of a magnetic material portion is flat and non-magnetic.
The thickness of the body part is larger than the thickness of the magnetic body part.
2. The gold for producing an anisotropic conductive sheet according to claim 1.
Type. 3. Along the surface of a substrate made of a magnetic metal,
A magnetic part and a non-magnetic part made of metal are arranged
A method for manufacturing a mold for manufacturing a structured anisotropic conductive sheet.
I, along the surface of the substrate, a technique of photolithography.
Heat-resistant polymer material cured by radiation
Forming a non-magnetic material portion consisting of
Plating and non-magnetic portions
The surface is flat and magnetic by polishing the plated part.
Made of an anisotropic conductive sheet characterized by forming a body part
Manufacturing method of molding die. 4. Along the surface of a substrate made of a magnetic metal,
A magnetic part and a non-magnetic part made of metal are arranged
A method for manufacturing a mold for manufacturing a structured anisotropic conductive sheet.
I, along the surface of the substrate, a technique of photolithography.
Heat-resistant polymer material cured by radiation
Forming a non-magnetic portion of the first layer comprising:
In the area where the non-magnetic part is not formed,
The surface is flat by polishing the
Forming a flat magnetic material portion, further comprising a non-magnetic material of the first layer;
Forming a nonmagnetic portion of the second layer on the portion
A method for manufacturing a mold for manufacturing an anisotropic conductive sheet. 5. An anisotropic conductor according to claim 1 or claim 2.
It is manufactured using a mold for manufacturing conductive sheets.
Anisotropic conductive sheet. 6. The method according to claim 3 or 4,
Therefore , using the manufactured anisotropic conductive sheet manufacturing mold
An anisotropic conductive sheet, which is manufactured.