JPH11204178A - Anisotropic conductive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropic conductive sheet which is easy to align with an electrode and ensures a required electric connection even if an arrangement pitch of the electrodes is small in an electric connection work. . Provided is an anisotropic conductive sheet capable of stably maintaining good electrical connection against environmental changes such as heat history due to temperature change and obtaining high connection reliability. SOLUTION: An insulating sheet body having a large number of through holes extending in the thickness direction, and a conductive path integrally provided in the through hole of the insulating sheet body so as to be filled in the through hole. The device comprises an element and the insulating sheet is a laminate having at least one elastic layer and at least one rigid layer. The insulating sheet body has two or more rigid layers, the outermost layer on one surface side and the other surface side of the insulating sheet body is a rigid layer, and the conductive path element is formed from at least one surface of the insulating sheet body. It is preferable to have a pressed portion that protrudes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anisotropic conductive sheet which is preferably used as an electrical connection between circuit elements such as electronic parts and a connector in an inspection apparatus for printed circuit boards and semiconductor elements.

[0002]

2. Description of the Related Art An anisotropic conductive elastomer sheet has conductivity only in the thickness direction, or has a pressurized conductive portion which has conductivity only in the thickness direction when pressed in the thickness direction. And it is possible to achieve a compact electrical connection without using means such as soldering or mechanical fitting, and it is possible to absorb mechanical shocks and strains and make a soft connection Because of these features, using such features, for example, computers,
In the fields of electronic digital watches, electronic cameras, computer keyboards, etc., they are widely used as connectors for achieving electrical connection between, for example, a printed circuit board and a leadless chip carrier, a liquid crystal panel, and the like. .

A circuit board such as a printed board or a circuit element having a hemispherical electrode on its surface, for example, FC (Fl
ip Chip) type, BGA (Ball Glid A)
(rray) type, CSP (Chip Scale Pac)
In an electrical inspection of a semiconductor device such as a kage type, an electrical connection between an electrode to be inspected formed on one surface of a circuit board or a circuit element to be inspected and a connection electrode formed on the surface of the inspection circuit substrate. In order to achieve an ideal connection and to prevent damage to the electrode to be inspected, an anisotropic conductive elastomer is placed between the electrode area to be inspected of the circuit board or circuit element and the connection electrode area of the circuit board for inspection. Interposition of a sheet is performed.

Conventionally, as such an anisotropic conductive elastomer sheet, those having various structures are known. For example, Japanese Patent Application Laid-Open No. Sho 51-93393 discloses that metal particles are uniformly dispersed in an elastomer. Anisotropic conductive elastomer sheet (hereinafter referred to as “dispersion type anisotropic conductive elastomer sheet”) obtained by the method described in JP-A-53-147772 is disclosed. By distributing the particles non-uniformly in the elastomer, an anisotropic conductive elastomer sheet (hereinafter, referred to as an electrically conductive elastomer sheet) in which a number of conductive path forming portions extending in the thickness direction and insulating portions that insulate them from each other are formed. "Eccentrically distributed anisotropic conductive elastomer sheet") is disclosed.
Japanese Unexamined Patent Publication No. 250906/2005 discloses an unevenly distributed anisotropic conductive elastomer sheet in which a step is formed between the surface of a conductive path forming portion and an insulating portion.

On the other hand, recently, the number of electrodes has increased along with the sophistication and capacity of circuit elements such as semiconductor elements, and the arrangement pitch of electrodes, that is, the center-to-center distance between adjacent electrodes has become smaller, resulting in higher density. The same applies to a circuit board on which such a circuit element is mounted. And, in order to perform an electrical inspection of such a circuit element or a circuit board, since the unevenly distributed anisotropic conductive elastomer sheet has a conductive path forming portion formed according to a pattern corresponding to an electrode pattern of the circuit element or the like, Compared to the dispersed anisotropic conductive elastomer sheet, the electrical connection between the electrodes can be achieved with high reliability even for circuit elements in which the electrodes to be connected are arranged at a small pitch. Is advantageous.

However, it has been found that such unevenly distributed anisotropically conductive elastomer sheets have the following problems. The unevenly distributed anisotropically conductive elastomer sheet is to be aligned with a conductive path forming portion of the unevenly distributed anisotropically conductive elastomer sheet and an electrode to be connected thereto in an electrical connection work with a circuit element or the like. is necessary. However, since the unevenly distributed anisotropically conductive elastomer sheet has high flexibility, it is liable to undergo large deformation and bending, and is inconvenient to handle.
Because it expands and contracts not only in the thickness direction of the sheet but also in the plane direction,
Electrical work cannot be performed while maintaining the positional relationship between the conductive path forming portions. Therefore, it is difficult to perform positioning with high accuracy.

[0007] Further, even if the alignment is realized once, if the influence of the thermal history due to the temperature change, that is, the influence of the thermal expansion and the thermal contraction, etc., is a large property which is an essential property of the elastomer. There is a problem that a stable connection state cannot be obtained because the thermal expansion coefficient is disturbed and a positional shift due to a temperature change occurs.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
In the electrical connection work, even if the arrangement pitch of the electrodes to be connected is small, alignment with the electrodes is easy,
An object of the present invention is to provide an anisotropic conductive sheet capable of reliably achieving required electric connection. Another object of the present invention is to provide an anisotropically conductive sheet in which good electrical connection is stably maintained even with environmental changes such as heat history due to temperature change, and high connection reliability is obtained. is there.

[0009]

According to the present invention, there is provided an anisotropic conductive sheet comprising: an insulating sheet having a plurality of through-holes extending in a thickness direction; a through-hole formed in the insulating sheet; And a conductive path element integrally provided in a state of being filled in the hole, wherein the insulating sheet body comprises:
It is characterized by being constituted by a laminate having at least one elastic layer and at least one rigid layer.

[0010] In the anisotropic conductive sheet of the present invention, the insulating sheet has at least two rigid layers, and at least one surface of the insulating sheet, preferably one surface and the other surface. It is preferable that the outermost layer is a rigid layer, and the conductive path element has a projecting portion projecting from at least one surface, preferably one surface and the other surface of the insulating sheet body. Further, it is preferable that the conductive path element is one in which conductive particles are contained in an elastic polymer material.

[0011]

According to the above construction, since the insulating sheet body constituting the skeleton has the rigid layer, deformation and bending are extremely small and handling is excellent. Therefore, in the electrical connection operation, the electrode to be connected and the conductive path element can be easily aligned with high accuracy, and as a result, the required electrical connection can be reliably achieved.
Moreover, since the insulating sheet body has an elastic layer,
When the conductive path element is pressed, the force applied to the conductive path element is reduced by the elastic layer, so that high durability can be obtained.

Further, since the outermost layers on one surface side and the other surface side of the insulating sheet body are formed of a rigid layer, the position of the conductive path element having the pressed portion is regulated by the rigid layer. Therefore, by using a material having a small coefficient of thermal expansion as a material constituting the rigid layer, thermal deformation of the entire anisotropic conductive sheet with respect to a temperature change becomes small, and thereby, a positional relationship between the conductive path elements is reduced. Is always maintained in a constant state, so that a good electrical connection state can be stably maintained even with environmental changes such as heat history due to temperature changes, and as a result, high connection reliability is obtained. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the anisotropic conductive sheet of the present invention will be described in detail. FIG. 1 is an explanatory cross-sectional view showing a configuration of a main part in an example of the anisotropic conductive sheet of the present invention. In this anisotropic conductive sheet, a large number of through holes 11 extending through in the thickness direction according to a specific pattern.
The insulating sheet body 10 on which is formed is provided. The specific pattern in the through hole 11 of the insulating sheet body 10 is a pattern corresponding to the pattern of the electrode to be connected. In each of the through holes 11 of the insulating sheet body 10, a conductive path element 20 is provided integrally with the insulating sheet body 10 in a state where the conductive path element 20 is filled in the through hole 11. Each of the 20 is substantially independent of each other. Further, in the conductive path element 20, pressed portions 21 and 22 protruding from one surface and the other surface of the insulating sheet body 10 are formed.

The insulating sheet body 10 is composed of two rigid layers 12 and 13 made of a rigid insulating material, and an insulating elastic polymer material provided between the rigid layers 12 and 13. It is composed of a laminate with the elastic layer 14.

Examples of the insulating material constituting the rigid layers 12 and 13 include resin materials having high mechanical strength such as polyimide, polyester and polyamide, glass fiber reinforced epoxy resin, glass fiber reinforced polyester resin, and glass fiber reinforced type. A composite resin material such as a polyimide resin or a composite resin material in which an inorganic material such as silica, alumina or boron nitride is mixed as a filler in an epoxy resin or the like can be used. A composite resin material such as a type epoxy resin or an epoxy resin mixed with boron nitride as a filler is preferable.

As the elastic high molecular substance constituting the elastic layer 14, a high molecular substance having a crosslinked structure is preferable. Examples of the curable polymer material forming material that can be used to obtain such a crosslinked polymer material include silicone rubber, polybutadiene rubber, natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer. Conjugated diene rubbers such as united rubber and hydrogenated products thereof, styrene-butadiene-diene block copolymer rubber, block copolymer rubbers such as styrene-isoprene block copolymer and hydrogenated products thereof, chloroprene, urethane Examples include rubber, polyester rubber, epichlorohydrin rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, and soft liquid epoxy rubber.

As shown in an enlarged manner in FIG.
Reference numeral 0 denotes a structure in which the conductive particles R are contained in the elastic polymer material E. Preferably, the conductive particles R are oriented in the elastic polymer material E in a state of being arranged in the thickness direction. The particles R form a conductive path in the thickness direction of the conductive path element 20. The conductive path element 20 may be a pressurized conductive path element in which a resistance value is reduced when pressed and compressed in the thickness direction to form a conductive path. Also,
In the cross section perpendicular to the thickness direction of the conductive path element 20, the conductive path of the conductive path element 20 may be formed over the entire area, or may be formed only in a part of the area, for example, only the central area.

Pressed portions 21 and 2 in conductive path element 20
2 are preferably 25% or less, particularly 5 to 15%, of the total thickness T of the anisotropic conductive sheet. Further, the total thickness T of the anisotropic conductive sheet is preferably 250% or less, and more preferably 150 to 100%, of the arrangement pitch p which is the distance between the centers of the adjacent conductive path elements 20. By satisfying these conditions,
The electrical connection between the electrode to be connected and the conductive path element 20 is reliably achieved, and when the pressure applied to the conductive path element 20 changes, the conductive path element 20
Is sufficiently suppressed to be small.

The conductive path element 20 is formed by hardening a fluid conductive path element material in which conductive particles are dispersed in a polymer material forming material which is cured to become an elastic polymer substance. You. Various materials can be used as the polymer material forming material used for the conductive path element material, and specific examples thereof include silicone rubber, polybutadiene rubber, natural rubber, polyisoprene rubber, and styrene-butadiene copolymer. Rubber, conjugated diene rubbers such as acrylonitrile-butadiene copolymer rubber and hydrogenated products thereof, styrene-butadiene-diene block copolymer rubber, block copolymer rubber such as styrene-isoprene block copolymer and the like Examples include hydrogenated products, chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, and soft liquid epoxy rubber. Among them, silicone rubber is preferred in terms of moldability and electrical properties.

The silicone rubber is preferably one obtained by crosslinking or condensing a liquid silicone rubber. 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 them, 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. Further, from the viewpoint of heat resistance of the obtained conductive path element 20, 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). Those having 2.0 or less are preferable.

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 a hydroxyl group-containing polydimethylsiloxane has a molecular weight Mw of 10,000 to 400.
00 is preferred. Further, from the viewpoint of heat resistance of the obtained conductive path element 20, the molecular weight distribution index is 2.
Those having 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.

The material for the conductive path element may contain a curing catalyst for curing the above-mentioned polymer-forming 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 those that can be used as a catalyst for the hydrosilylation reaction include:
Chloroplatinic acid and its salts, platinum-unsaturated group-containing siloxane complex, complex of vinylsiloxane and platinum, complex of platinum and 1,3-divinyltetramethyldisiloxane, complex of triorganophosphine or phosphite and platinum And acetylacetate platinum chelate, and a complex of a cyclic diene and platinum. The amount of the curing catalyst to be used is appropriately selected in consideration of the type of the polymer substance forming material, the type of the curing catalyst, and other curing treatment conditions.
１５15 parts by weight.

As the conductive particles R used in the material for the conductive path element, it is preferable to use conductive magnetic particles from the viewpoint that the particles can be easily oriented by a method described later. Specific examples of the conductive magnetic particles include iron, nickel, particles of a metal exhibiting magnetism such as cobalt, particles of an alloy thereof, or particles containing these metals, or these particles as core particles. The core particles are obtained by plating the surface of a core particle 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 as core particles. On the surface of the particles,
Examples thereof include those plated with a conductive magnetic material such as nickel and cobalt, and those obtained by coating core particles with both a conductive magnetic material and a metal having good conductivity.
Among them, it is preferable to use nickel particles as core particles, the surfaces of which are 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 R 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 The ratio of the conductive metal coating area to the particle surface area) is preferably 40% or more, more preferably 45% or more, and particularly preferably 47 to 95%.
It is. The amount of the conductive metal coating is 2.5% of the core particles.
To 50% by weight, more preferably 3% by weight.
To 30% by weight, more preferably 3.5 to 25% by weight,
Particularly preferably, it is 4 to 20% by weight. When the conductive metal to be coated is gold, the coating amount is 3% of the core particle.
It is preferably from 30 to 30% by weight, more preferably from 3.5 to 15% by weight, further preferably from 4 to 20% by weight, particularly preferably from 4.5 to 10% by weight. Also,
When the conductive metal to be coated is silver, the coating amount is preferably 3 to 30% by weight of the core particles, more preferably 4 to 25% by weight, and still more preferably 5 to 2% by weight.
It is 3% by weight, particularly preferably 6 to 20% by weight.

The particle diameter of the conductive particles R is 1 to 10
00 μm, more preferably 2 to 5 μm.
The thickness is 00 μm, more preferably 5 to 300 μm, and particularly preferably 10 to 200 μm. The particle size distribution (Dw / Dn) of the conductive particles R is preferably 1 to 10, more preferably 1 to 7, and still more preferably 1 to 7.
5, particularly preferably 1 to 4. By using the conductive particles R satisfying such conditions, the obtained conductive path element 20 can be easily deformed under pressure. Contact is obtained. The shape of the conductive particles R is not particularly limited. However, since the conductive particles R can be easily dispersed in the polymer material, they may be spherical, star-shaped or aggregated. It is preferably a lump formed by the secondary particles.

The water content of the conductive particles R 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 R satisfying such conditions, it is possible to prevent bubbles from being generated in the conductive path element material layer when the conductive path element material layer is cured in the manufacturing method described below. Or be suppressed.

The conductive particles R 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 adhesiveness between the conductive particles R and the elastic polymer substance E is increased, and as a result, the obtained conductive path element 20 can be used repeatedly. The durability is high. The amount of the coupling agent used is appropriately selected within a range that does not affect the conductivity of the conductive particles R,
It is preferable that the coating rate of the coupling agent on the surface of the conductive particles R (the ratio of the coating area of the coupling agent to the surface area of the conductive core particles) is 5% or more, and more preferably, the coating rate is more than 5%. 7 to 100%, more preferably 10 to 100%, particularly preferably 20 to 10
The amount is 0%.

Such conductive particles R are 30 to 60% by volume, preferably 35% by volume, based on the polymer material.
Preferably, it is used at a ratio of up to 50%. If this ratio is less than 30%, the conductive path element 20 having a sufficiently small electric resistance may not be obtained. On the other hand, when this ratio exceeds 60%, the obtained conductive path element 2
0 tends to be brittle, and the elasticity required for the conductive path element 20 may not be obtained.

In the material for the conductive path element, if necessary,
An inorganic filler such as ordinary silica powder, colloidal silica, airgel silica, and alumina can be contained. By including such an inorganic filler, the thixotropic property of the conductive path element material is secured, the viscosity is increased, and the dispersion stability of the conductive particles is improved, and the conductive particles are cured. Conductive path element 2
0 has a higher intensity. The use amount of such an inorganic filler is not particularly limited, but when used in an excessively large amount, in the production method described later, it becomes impossible to sufficiently achieve the orientation of the conductive particles by a magnetic field,
Not preferred. The viscosity of the conductive path element material is preferably in the range of 10,000 to 1,000,000 cp at a temperature of 25 ° C. Then, the above-described material for the conductive path element is cured to form the conductive path element 2.
0 is formed.

The above-described anisotropic conductive sheet can be manufactured, for example, through the following first to fourth steps. [First Step] In the first step, finally, as shown in FIG. 4, a rigid layer 12 made of an insulating material and a thin metal layer are formed on the upper surface of an elastic layer 14 made of an insulating elastic polymer material. 1
6 is a step of fabricating an intermediate laminated body in which a rigid layer 13 made of an insulating material and a thin metal layer 17 are laminated in this order on the lower surface of the elastic layer 14. Specifically, as shown in FIG.
A sheet 12A for forming a rigid layer is superimposed on the upper surface of 4A,
Further, a metal foil 1 is formed on the upper surface of the rigid layer forming sheet 12A.
6A are superimposed. On the other hand, a rigid layer forming sheet 13A is superposed on the lower surface of the elastic layer sheet 14A, and a metal foil 17A is further superimposed on the lower surface of the rigid layer forming sheet 13A. Here, as the rigid layer forming sheets 12A and 13A, a glass fiber reinforced epoxy prepreg resin sheet, a polyimide prepreg resin sheet, an epoxy prepreg resin sheet, or the like can be used.

Then, in this state, the sheets 12A and 13A for forming the rigid layer are integrally attached with the upper and lower surfaces of the sheet 14A for the elastic layer being applied by thermocompression treatment, for example, by a vacuum press method. Further, the metal foils 16A and 17A are integrally attached to the upper surface of the rigid layer forming sheet 12A and the rigid layer forming sheet 13A, and the rigid layer forming sheets 12A and 13A are cured, whereby As shown in FIG. 4, the thin metal layer 16 and the rigid layer 1
2. An intermediate laminate 10A in which the elastic layer 14, the rigid layer 13, and the thin metal layer 17 are laminated in this order from above is formed.

In the above description, the heating temperature in the thermocompression bonding treatment depends on the material of the rigid layer forming sheets 12A and 13A, but is higher than the temperature at which the rigid layer forming sheets 12A and 13A are softened and have adhesiveness. It is usually 80 to 250 ° C, preferably about 140 to 200 ° C. The pressing pressure in the thermocompression bonding is, for example, about 5 to 50 kg / cm ^{2 at the} maximum, and preferably ² to 50 kg / cm 2.
It is about 0 to 40 kg / cm ² . This thermocompression bonding process
Although it is possible to carry out the reaction under a normal pressure atmosphere, in practice, it is preferable to use a so-called vacuum press method under a reduced pressure atmosphere of, for example, about 5 to 100 Pa, preferably about 10 to 50 Pa. Sheet 12A, 1
Entrapment of air bubbles between 3A and the adherend surface is effectively prevented.

[Second Step] In the first step, as shown in FIGS. 5 and 6, a large number of through holes 11 extending in the thickness direction are formed in the intermediate laminated body 10A, and the intermediate laminated body 10A is formed. This is a step of forming the conductive path element material layer 20A filled in the through holes 11 of FIG. Specifically, as shown in FIG. 5, by drilling holes in the intermediate laminate 10A, a large number of through holes 11 penetrating in the thickness direction are formed in the intermediate laminate 10A.
Here, as means for drilling holes in the intermediate laminate 40A, for example, means by drilling with a numerically controlled drilling device or the like, means by laser processing, or the like can be used.

Next, the above-described material for the conductive path element is applied to the surface of the intermediate laminate 10A, thereby filling the inside of each through hole 11 of the intermediate laminate 10A with the material for the conductive path element. As shown in FIG. 6, a conductive path element material layer 20A is formed in each of the through holes 11. afterwards,
If necessary, unnecessary conductive path element material adhering to the surface of the intermediate laminate 10A is removed with a squeegee or the like. In the above description, as a means for applying the conductive path element material, a means by printing such as screen printing can be used.

[Third Step] In this third step, as shown in FIGS. 7 and 8, the conductive path element material layer 20A filled in the through holes 11 of the intermediate laminate 10A is cured. Thereby, the conductive path element 20 integrally provided in a state of being filled in the through hole 11 of the intermediate laminate 10A is formed, and the thin metal layer 16 of the intermediate laminate 10A is formed.
17 is a step of manufacturing an anisotropic conductive sheet having the configuration shown in FIG. Specifically, as shown in FIG. 7, an intermediate laminate 10A in which a conductive path element material layer 20A is formed in the through-hole 11 is disposed between a pair of electromagnets 25 and 26. 26, a parallel magnetic field acts in the thickness direction of the conductive path element material layer 20A, and as a result, the conductive particles dispersed in the conductive path element material layer 20A are removed from the conductive path element material layer 20A. Layer 20A
Oriented in the thickness direction. Then, in this state, by curing the conductive layer element material layer 20A, the conductive path element 20 is formed in the through hole 11 of the intermediate laminate 10A as shown in FIG.

In the above, the conductive layer element material layer 20A
Can be performed with the parallel magnetic field applied, but can also be performed after the parallel magnetic field is stopped. The strength of the parallel magnetic field applied to the conductive path element material layer 20A is preferably 200 to 10000 gauss on average.

The curing treatment of the conductive path element material layer 20A is as follows.
Although it is appropriately selected depending on the material used, it is usually performed by a heat treatment. When the conductive path element material layer 20A is cured by heating, the electromagnets 25 and 26 may be provided with heaters. The specific heating temperature and heating time are appropriately selected in consideration of the type of the polymer material forming material constituting the conductive path element material layer 20A, the time required for the movement of the conductive particles, and the like.

Then, the thin metal layer 1 of the intermediate laminate 10A
As shown in FIG. 1, the insulating sheet body 10 having a plurality of through holes 11 and the through holes 1 of the insulating sheet body 10
An anisotropic conductive sheet filled with the conductive path element 20 and having the pressed portions 21 and 22 protruding from the upper surface and the lower surface of the insulating sheet body 10 is obtained.

Such an anisotropic conductive sheet is used for inspection of a circuit element such as a semiconductor element as follows, for example. In the inspection of circuit elements, as shown in FIG.
An inspection circuit board 4 having a connection electrode 5 disposed on the surface thereof in accordance with a pattern opposite to a protruding electrode 3 to be inspected of a circuit element 2 to be inspected is used. The anisotropic conductive sheet 1 is placed on the surface of the inspection circuit board 4.
To the pressed portion 22 of the conductive path element 20 on the other surface side.
Are arranged so as to be located on the connection electrode 5, and the circuit element 2 is placed on one surface of the anisotropic conductive sheet 1 such that the electrode 3 to be inspected is located on the pressed portion 21 of the conductive path element 20. Deploy.

Then, for example, by moving the circuit element 2 in a direction approaching the inspection circuit board 4, the pressed parts 21 and 22 of the conductive path element 20 in the anisotropic conductive sheet 1 are moved.
2 is pressed against the circuit element 2 and the inspection circuit board 4, and the pressing force forms a conductive path extending in the thickness direction in the conductive path element 20 of the anisotropic conductive sheet 1. As a result, the electrical connection between the electrode 3 to be inspected of the circuit element 2 and the connection electrode of the inspection circuit board 4 is achieved, and the required electrical inspection of the circuit element 2 is performed in this state.

According to the above-described anisotropic conductive sheet, since the insulating sheet body 10 constituting the skeleton thereof has the rigid layers 12 and 13, the deformation and deflection are extremely small and the handling is good. In the electrical connection operation, the electrode to be connected and the conductive path element 20 can be easily aligned with high accuracy, and as a result, required electrical connection can be reliably achieved. In addition, since the insulating sheet body 10 has the elastic layer 14, the conductive path element 20
Is pressed, the force applied to the conductive path element 20 is reduced by the elastic layer 14, so that high durability is obtained.

Further, since the outermost layers on one side and the other side of the insulating sheet body 10 are constituted by the rigid layers 12, 13, the pressed parts 21,
Since the position of the conductive path element 20 having the position 22 is regulated,
By using a material having a small coefficient of thermal expansion as a material for forming the rigid layers 12 and 13, thermal deformation of the entire anisotropic conductive sheet with respect to a temperature change becomes small. Since the positional relationship is always maintained in a constant state, it is possible to stably maintain a good electrical connection state against environmental changes such as heat history due to temperature changes, and as a result, high connection reliability is achieved. can get.

Although the embodiment of the present invention has been described above, the present invention is not limited to the anisotropic conductive sheet shown in FIG. 1, and various modifications can be made. For example, the insulating sheet body 10 may have various configurations as long as it is a laminate having at least one elastic layer and at least one rigid layer. Specifically, as shown in FIG. 10, the insulating sheet body 10 may be configured by a laminate in which elastic layers 14 and 15 are laminated on the upper surface and the lower surface of the rigid layer 12, respectively. Also, the insulating sheet 1
0 is not limited to a laminate having a three-layer structure,
It may be a laminate having more than two layers.

[0046]

According to the anisotropic conductive sheet of the first aspect, since the insulating sheet constituting the skeleton has a rigid layer, deformation and deflection are extremely small and handling is good. In the electrical connection operation, the electrode to be connected and the conductive path element can be easily aligned with high accuracy, and as a result, required electrical connection can be reliably achieved. Moreover, since the insulating sheet body has the elastic layer, when the conductive path element is pressed, the force applied to the conductive path element is reduced by the elastic layer, so that high durability can be obtained.

According to the anisotropic conductive sheet of the second aspect, since the outermost layers on one side and the other side of the insulating sheet body are formed of the rigid layer, the pressed portion is formed by the rigid layer. Since the position of the conductive path element is restricted, by using a material having a small coefficient of thermal expansion as a material forming the rigid layer, thermal deformation with respect to a temperature change of the entire anisotropic conductive sheet becomes small, and Thereby, since the positional relationship of each of the conductive path elements is always maintained in a constant state, it is possible to stably maintain a good electrical connection state with respect to environmental changes such as heat history due to temperature changes. As a result, high connection reliability is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a configuration of an example of an anisotropic conductive sheet of the present invention.

FIG. 2 is an explanatory sectional view showing a part of the anisotropic conductive sheet of FIG. 1 in an enlarged manner.

FIG. 3 is an explanatory sectional view showing an arrangement state of members for obtaining an intermediate laminate.

FIG. 4 is an explanatory cross-sectional view illustrating a configuration of an intermediate laminate.

FIG. 5 is an explanatory cross-sectional view showing a state in which a through hole is formed in the intermediate laminate.

FIG. 6 is an explanatory cross-sectional view showing a state in which a conductive path element material is formed in a through hole of an intermediate laminate.

FIG. 7 is an explanatory cross-sectional view showing a state in which a parallel magnetic field is applied to a conductive path element material formed in a through hole of an intermediate laminate.

FIG. 8 is an explanatory cross-sectional view showing a state in which a conductive path element is integrally formed in a through hole of the intermediate laminate.

9 is an explanatory cross-sectional view showing a state in which the anisotropic conductive sheet shown in FIG. 1 is interposed between a circuit element to be inspected and a circuit board for inspection.

FIG. 10 is an explanatory cross-sectional view showing a configuration of another example of the anisotropic conductive sheet of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Anisotropic conductive sheet 2 Circuit element 3 Electrode to be inspected 4 Inspection circuit board 5 Connection electrode 10 Insulating sheet body 10A Intermediate laminated body 11 Through hole 12, 13 Rigid layer 12A, 13A
Sheet for forming rigid layer 14, 15 Elastic layer 14A Sheet for elastic layer 16, 17 Thin metal layer 16A, 17A
Metal foil 20 Conductive path element 20A Material layer for conductive path element 21, 22 Pressed portion 25, 26 Electromagnet E Elastic polymer substance R Conductive particle

Claims (2)

[Claims] An insulating sheet having a plurality of through-holes extending in a thickness direction thereof, and a plurality of through-holes formed in the insulating sheet and integrally provided in the through-holes. An anisotropic conductive sheet comprising: a conductive path element; wherein the insulating sheet body is constituted by a laminate having at least one elastic layer and at least one rigid layer. 2. The insulating sheet body has two or more rigid layers, and outermost layers on one surface side and the other surface side of the insulating sheet body are rigid layers. 2. A pressing part protruding from at least one surface of the sheet member.
The anisotropic conductive sheet according to 1.