JP2000006293A - Electrically conductive laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a simple and sure electrical connection of an electrically conductive elastic body by constituting of an electrically conductive elastic body layer, an electrically conductive body intermediate layer, and an elastic body layer. SOLUTION: The electrically conductive laminate comprises an electrically conductive elastic body layer 9, an electrically conductive body intermediate layer 8 other than this layer, and an elastic body layer 7 other than these layers. The electrically conductive elastic body layer 9 is arranged with electrically conductive particles into a macromolecule having elasticity, and constructed of electrically conductive particles and rubber-like polymer, the volume percentage of the electrically conductive particles being preferably 5-50%. The electrically conductive elastic body layer 9 is preferably an anisotropic electrically conductive rubber polymer. The surface of the electrically conductive elastic body layer 9 can have the unevenness corresponding to that of an object to be connected. The electrically conductive intermediate body 8 is preferably a metal thin layer, and the elastic body layer 7 is preferably at least one selected from a macromolecular elastic body gel composition and a hollow body containing air or liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive laminate used for an electrical inspection of an inspection object having circuit wiring. Further, the present invention relates to a conductive laminate and an apparatus for inspecting a circuit board using the same, which are useful for, for example, conducting inspection of a narrow pitch electrode surface of a semiconductor package substrate such as a chip carrier substrate such as a CSP and a step substrate.

[0002]

2. Description of the Related Art In recent years, electronic devices have become smaller and more portable, and the circuit boards used for them have been increasingly dense and fine in circuit wiring. Also, due to changes in the mounting method of electronic components, the electrodes on the substrate are becoming narrower and denser.
Also, the electrode area has been reduced. Further, the substrate surface is also diversified with steps. For example, in the case of the flip-chip mounting method, 30 μm
There is a slight resist step. In addition, a substrate having a step of, for example, about 0.3 to 0.5 mm has appeared in an electrode portion of a substrate corresponding to a wire bonding mounting method called a cavity type substrate. Conventionally, in the electrical continuity inspection of the wiring of these circuit boards, the continuity inspection and the insulation inspection have been performed by originally contacting a pin probe with terminal electrodes at both ends of the circuit wiring. However, when the circuit board has a high density, the inspection jig using the pin probe needs to have a high density of the terminal intervals, and its manufacture is not easy and expensive. Further, in the case of a cavity type substrate, there is a substrate having a large step and making an electrical continuity inspection itself difficult. As a means for solving this problem and conducting a continuity test of wiring at low cost, a test using conductive rubber is performed. For example, as shown in FIG. 1, a conductive rubber is placed on the surface of a circuit board on which a fine electrode group is present, and a continuity test is performed on the electrode group having a wide electrode gap on the rear surface with a pin probe or an anisotropic conductive rubber. As a result, it is possible to confirm whether or not one of the fine electrodes is disconnected from the electrode on the back surface connected to the fine electrode by wiring. Further, by performing an electrical insulation test using an insulating sheet instead of the conductive rubber, it is possible to confirm the presence or absence of a leak between the fine electrode group and the electrode group having a wide electrode gap on the back surface. Thus, the combination of conductive rubber and inexpensive pin probe or anisotropic conductive rubber,
An inexpensive inspection jig.

[0003]

However, with the recent spread of new high-density mounting methods such as flip-chip mounting, for example, as shown in FIG. The permanent insulating layer of the circuit board is present in a more convex state than the electrode, and the position of the fine electrode of the circuit board is located at the bottom of the concave portion surrounded by the insulating layer, and the conventional conductive rubber Therefore, it has become difficult to make stable electrical contact, and there has been a demand for the development of a new conductive elastic body capable of simple and reliable electrical connection and a circuit board inspection apparatus using the same.

[0004]

The present invention relates to (A) a conductive elastic layer, (B) a conductive intermediate layer other than (A), and (C) an elastic layer other than (A). It is intended to provide a conductive laminate characterized by the following. Also, the present invention
(A) An object of the present invention is to provide the above-mentioned conductive laminate, wherein the conductive elastic layer is obtained by mixing conductive particles in a polymer having elasticity. The (A) conductive elastic layer is preferably composed of conductive particles and a rubber-like polymer, and preferably has a volume fraction of 5 to 50%. Also,
(A) The conductive elastic layer is preferably an anisotropic conductive rubber-like polymer. Further, (A) the surface of the conductive elastic layer can have unevenness corresponding to the unevenness of the connection object. It is preferable that the (B) conductor intermediate layer is a thin metal layer. The elastic layer is preferably at least one selected from a polymer elastic gel composition and a hollow body containing a gas or a liquid. Further, the present invention provides a circuit board inspection apparatus, wherein the conductive laminate, the circuit board and the inspection apparatus are electrically connected.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The conductive laminate of the present invention can be stably contacted with an electrode of a circuit board or the like by a specific structure, can make a reliable electric connection, and can reduce the distance between the electrodes. It can be applied to fine circuit boards.

The (A) conductive elastic layer of the present invention is a layer in which conductive particles are contained in a polymer having elasticity.
The polymer used in the conductive elastic layer (A) of the present invention is preferably an elastic insulator. As such an insulator having elasticity, a rubber-like polymer is preferable.
Examples of the rubbery polymer include conjugated diene rubbers such as polybutadiene, natural rubber, polyisoprene, SBR and NBR, and hydrogenated products thereof, and block copolymers such as styrene butadiene diene block copolymer and styrene isoprene block copolymer. Coalescence and their hydrogenated products,
Chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, silicone rubber, ethylene propylene copolymer, ethylene propylene diene copolymer and the like can be mentioned. When weather resistance is required, a rubber-like polymer other than the conjugated diene rubber is preferred, and silicon rubber is particularly preferred from the viewpoint of moldability and electrical properties.

Here, the silicone rubber will be described in more detail. As the silicone rubber, one obtained by crosslinking or condensing liquid silicone rubber is preferable. The liquid silicone rubber preferably has a viscosity of 105 poise or less at a strain rate of 10-1 sec, and may be any of a condensation type, an addition type, and a type containing a vinyl group or a hydroxyl group. Specific examples include dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, and methylphenyl vinyl silicone raw rubber. Among these, as the vinyl group-containing silicone rubber, usually, dimethyldichlorosilane or dimethyldialkoxysilane, in the presence of dimethylvinylchlorosilane or dimethylvinylalkoxysilane,
It can be obtained by hydrolysis and condensation reaction, for example, followed by fractionation by repeated dissolution-precipitation.

[0008] Further, those containing a vinyl group at both ends are polymerized by anionic polymerization of a cyclic siloxane such as octamethylcyclotetrasiloxane in the presence of a catalyst, and the polymerization is terminated by using a terminal terminator. When obtaining, it can be obtained by using, for example, dimethyldivinylsiloxane as a terminal stopper, and appropriately selecting reaction conditions (eg, the amount of the cyclic siloxane and the amount of the terminal stopper). Here, examples of the catalyst include alkalis such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide or silanolate solutions thereof, and the like.
The reaction temperature is, for example, 80 to 130 ° C.

[0009] The hydroxyl-containing silicone rubber is usually prepared by converting dimethyldichlorosilane or dimethyldialkoxysilane into a hydrosilane compound such as dimethylhydrochlorosilane, methyldihydrochlorosilane or dimethylhydroalkoxysilane.
It can be obtained by hydrolysis and condensation, followed by fractionation by repeated dissolution-precipitation. In addition, when the cyclic siloxane is anionically polymerized in the presence of a catalyst and the polymerization is terminated using a terminal stopper to obtain a polymer, the reaction conditions (eg, the amount of the cyclic siloxane and the amount of the terminal stopper) are selected. Can be obtained by using dimethylhydrochlorosilane, methyldihydrochlorosilane or dimethylhydroalkoxysilane as a terminal stopper. Here, examples of the catalyst include alkalis such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide or a silanolate solution thereof, and the reaction temperature is, for example, 80 to 130.
° C.

The molecular weight (weight average molecular weight in terms of standard polystyrene) of the rubbery polymer is preferably 10,000 to 40,000. The molecular weight distribution index of the rubbery polymer component (the ratio of the weight average molecular weight in terms of standard polystyrene to the number average molecular weight in terms of standard polystyrene (hereinafter referred to as “Mw / M”)
n) is preferably 2 or less from the viewpoint of heat resistance of the obtained conductive elastomer.

Examples of the conductive particles include known single conductive metal particles such as iron, copper, zinc, chromium, nickel, gold, silver, cobalt, and aluminum, and alloys or composites of two or more of these metal elements. Conductive metal particles, carbon black, and the like. Of these, carbon black, nickel, iron,
Conductive particles such as copper are preferable in terms of economy and conductive characteristics, and particularly preferably nickel particles whose surface is coated with gold or silver.

When silicon rubber is used as the insulator, the coverage of the conductive particles with the silane coupling agent is preferably 5% or more, more preferably 7% or more.
It is 100%, more preferably 10 to 100%, particularly preferably 20 to 100%. Further, the particle size of the conductive particles is preferably from 1 to 1000 μm, more preferably from 2 to 500 μm, more preferably from 3 to 300 μm.
m, particularly preferably 5 to 100 μm. According to the conductive particles having a particle size in such a range, in the obtained conductive elastomer, sufficient electric contact can be obtained between the conductive particles at the time of use. The shape of the conductive particles is not particularly limited, but is preferably spherical or star-shaped from the viewpoint of easy dispersion in the above-mentioned silicon rubber or the like.

The nickel particles whose surface is preferably coated with gold, which is particularly preferably used as the conductive particles in the present invention, are obtained by plating the surfaces of the nickel particles with gold by, for example, electroless plating. Thus, the nickel particles having a gold coating on the surface have extremely low contact resistance. When coating gold by plating, the film thickness is 1
It is preferably at least 2,000 angstroms. Further, the plating amount is preferably 1% by weight or more of the particles,
More preferably 2 to 10% by weight, particularly preferably 3 to 10% by weight.
7% by weight.

In the present invention, the compounding amount of the conductive particles is
The volume fraction is preferably 5% to 50%, more preferably 7%.
３０30%. In the weight ratio, in the case of metal particles,
It is used in a proportion of 30 to 1000 parts by weight, preferably 50 to 750 parts by weight, based on 100 parts by weight of the rubbery polymer. When this ratio is less than 30 parts by weight, the obtained conductive rubber does not have a sufficiently low electric resistance even during use,
Therefore, it does not have a good connection function.
If the amount exceeds 2,000 parts by weight, the cured conductive rubber becomes brittle, and it becomes difficult to use the conductive rubber as the conductive rubber. The conductive rubber composition of the present invention containing the above rubbery polymer and conductive particles may contain, as necessary, an inorganic filler such as ordinary silica powder, colloidal silica, airgel silica, and alumina. Can be. By including such an inorganic filler, the thixotropy at the time of uncuring is secured, the viscosity is increased, and the dispersion stability of the conductive particles is improved, and the strength of the conductive rubber after curing is improved. .

The amount of the inorganic filler used is not particularly limited, but if used in an excessively large amount, the conductive rubber becomes brittle. The viscosity of the conductive rubber composition of the present invention is 100,000 to 3,000, at a temperature of 25 ° C.
It is preferably in the range of 000 cp. The conductive rubber composition of the present invention has a function as a conductive rubber due to crosslinking or condensation reaction being performed to form a conductive rubber having high elasticity, and further including a specific conductive particle component. Become.

The conductive rubber composition of the present invention can use a curing catalyst for curing. Examples of such a curing catalyst include an organic peroxide, a fatty acid azo compound, a hydroxylation catalyst, and radiation. Examples of the organic peroxide include benzoyl peroxide, bisdicyclobenzoyl peroxide, dicumyl peroxide, and ditertiary butyl peroxide. Examples of the fatty acid azo compound include azobisisobutyronitrile. Specific examples of the catalyst that can be used as a catalyst for the hydrosilylation reaction include chloroplatinic acid and salts thereof, a siloxane complex containing a platinum-unsaturated group, a complex of vinyl siloxane and platinum, and a complex of platinum and 1,3-divinyl tetra. Known ones such as a complex with methyldisiloxane, a complex of triorganophosphine or phosphite with platinum, an acetylacetonate platinum chelate, and a complex of cyclic diene and platinum can be mentioned.

The method of adding the curing catalyst is not particularly limited. However, it is preferable that the curing catalyst is previously mixed with the rubber component, which is the main component, from the viewpoint of storage stability and prevention of uneven distribution of the catalyst when mixing the components. It is preferable to use an appropriate amount of the curing catalyst in consideration of the balance between the actual curing speed and the pot life. Further, a hydrosilylation reaction control agent such as an amino group-containing siloxane or a hydroxy group-containing siloxane, which is usually used for controlling the curing rate and the pot life, can be used in combination. When using rubber such as silicon rubber as the rubber-like polymer and using a magnetic substance such as nickel as the conductive particles, prior to or during curing,
By applying a magnetic field in the thickness direction of the conductive elastic layer,
The conductive particles can be oriented in the thickness direction of the conductive elastic layer, and can be an anisotropic conductive rubbery polymer.
The use of such an anisotropic conductive rubbery polymer is preferable in that the conductivity in the thickness direction can be increased and the conductivity is improved. It is also preferable in that the flexibility of the rubbery polymer is hardly impaired.

(A) The thickness of the conductive elastic layer is 0.05
10 to 10 mm, more preferably 0.1 to 2 m
m More preferably, it is 0.15 to 1 mm. In particular, when the (C) elastic layer of the back layer is a flexible one such as a gel composition or a water bed structure, the thickness is 0.1 to 0.5.
It is preferably a thin and flexible material having a thickness of mm. Further, depending on the surface shape of the connection object (object to be inspected), a step or a projection structure can be provided on the (A) conductive elastic layer.

(A) In order to form a step or a projection structure on the surface of the conductive elastic body layer, a mold having irregularities on the surface is simply prepared and used according to the surface of the object to be connected. Can be formed. The surface unevenness of such a mold is, for example, a method of cutting a metal such as brass or aluminum, or
This is possible by cutting glass epoxy resin or the like. This cutting process creates a mold with surface irregularities, and uses a flat mold for the other, and a liquid silicon compounded with nickel-plated gold on the surface between the two molds. By introducing the rubber composition and, if necessary, heating the mold in a parallel magnetic field, the conductive rubber sheet portion (22) can be formed with the configuration shown in FIG. In addition, it is preferable to provide a conductive projection protruding from the surface of the conductive elastic body layer (A). Such conductive projections are usually manufactured by means such as machining or plating, and the shape may be a column, a cone, a sphere, or a part thereof. The material is not particularly limited as long as it is an electric conductor, but is preferably a metal, particularly preferably copper or the like. Further, it is preferable that an oxide film that impairs conductivity is not easily formed on the surface, and it is more preferable that the surface is plated with gold or the like. As a specific example, it can be realized by a method such as embedding a metal pin having a surface treated with gold plating or the like after molding a conductive sheet or at the time of molding. From the viewpoint of simplicity and the like, a method using the following plated metal is preferable.

That is, a resist is applied to the surface of a flat mold, a predetermined pattern is formed by exposure and development, and as shown in FIG. 4, metal plating is started up at the opening of the resist by electrolytic plating. Using this mold on one side and a flat mold on the other side, a liquid silicone rubber and a composition consisting of nickel powder whose surface is gold-plated were introduced between two molds, as shown in FIG. In such a configuration, the conductive rubber sheet is formed by heating the mold in a parallel magnetic field as needed. After the molding, the temperature is lowered to room temperature, and then the mold is carefully removed, whereby a conductive rubber sheet having the metal projections transferred to the surface as shown in FIG. 6 can be obtained.

In order to prevent an oxide film from being formed on the surface of the projections after the transfer and impairing the conductivity, gold is first plated on the resist opening, and then copper or the like is plated. Can be obtained. When transferring the metal protrusions to the conductive rubber sheet, a part of the resist residue may also be transferred to the conductive rubber sheet. Therefore, after the transfer, it is preferable to sufficiently treat the conductive rubber sheet surface with a developer or a stripper. . When the protrusion amount of the protrusion is large or when the distance between the protrusions is short, the protrusion may remain on the mold without being transferred to the conductive sheet, so that the metal protrusion is surely transferred to the conductive rubber sheet. Before applying the resist, as a release layer, a method in which copper or the like is thinly plated on the surface of a flat mold, and the release layer is transferred to conductive rubber, and then the release layer is removed by etching. .

The amount of protrusion of the conductive projections from the sheet surface is from ± 2 μm to ± 100 with respect to the average thickness of the conductive rubber sheet.
μm, preferably ± 3 μm to ± 50 μm, and more preferably ± 5 μm to ± 40 μm.
Further, the distance between the peaks of the conductive protrusions is from 10 μm to 200 μm.
μm, preferably 15 μm to 150 μm, and more preferably 20 μm to 100 μm.
If the amount of protrusion of the conductive protrusion from the sheet surface is smaller than ± 2 μm with respect to the average thickness of the sheet, the conductive rubber cannot stably contact the electrode of the circuit board. Also ± 1
If it exceeds 00 μm, the projections themselves become large and cannot be used for inspection of narrow pitch electrodes on the circuit board.
If it is smaller than 0 μm, manufacturing becomes difficult, and it is difficult to form a conductive projection having a large protrusion amount. On the other hand, if the distance between the peaks of the conductive protrusions of the conductive rubber sheet exceeds 200 μm, it will not be possible to cope with the inspection of a circuit board having a narrow electrode interval (pitch).

The intermediate (B) conductive intermediate layer has the effect of assisting the lateral conductivity of the (A) conductive elastic layer. (B) The conductor intermediate layer may be a hard layer, but (A)
It is preferable that the layer (C) and the layer (C) be an elastic body and a flexible layer in order to accurately follow the surface irregularities of the connection object. (B) The thickness of the conductor intermediate layer is 0.005 to 1
0 mm is preferred, and more preferably 0.01 to 5 mm
It is. (B) When the conductive intermediate layer is a metal, its thickness is preferably 0.005 to 0.5 mm, more preferably 0.01 to 0.2 mm, and particularly preferably 0.01 to 0.2 mm.
5 to 0.1 mm. (B) The thickness of the conductor intermediate layer is:
If it is too thick, it may lack flexibility, and if it is too thin, it may be difficult to obtain sufficient conductivity or durability may be poor. (B) The conductivity of the conductor intermediate layer is preferably 5 to 1 × 10 ⁻⁶ Ωcm, more preferably 2 to 2 × 10 ⁻⁶ Ωcm, and particularly preferably 1 to 5 × 10 ⁻⁶ Ωcm. is there.

(B) As the conductor intermediate layer, a metal, a conductive polymer or the like can be used. Specific examples of these include aluminum, copper, gold, silver, nickel, iron, zinc, and the like. Preferred examples of these are thin sheets of metal such as aluminum foil, copper foil and gold foil. Alternatively, these metals can be laminated, laminated, plated, on a sheet of resin, rubber, elastomer, etc.
The metal may be disposed by means such as vapor deposition or paste application, or these metals may be laminated on the inner surface side of the (A) conductive elastic layer or (C) elastic layer,
It may be arranged by means such as plating, vapor deposition, or application of a paste.

(C) It is preferable that the elastic body layer has elasticity and can withstand a pressing force to some extent. Specific examples thereof include at least one selected from an elastic polymer, a gel composition, and a hollow body containing a gas or a liquid. (C) The elastic layer comprises (A)
This has the effect of assisting the dimensional absorption capacity of the conductive elastic layer in the thickness direction. (C) The thickness of the elastic layer is 1 to 10 mm
Is preferably 1.5 to 8 mm, more preferably 2 to 7 mm. If the thickness is too large, workability is poor, and if it is too small, the effect of dimensional absorption is low.

As the polymer elastic body, a rubber-like polymer, an elastomer or the like is preferable. Examples of rubbery polymers include polybutadiene, natural rubber, polyisoprene, SBR, N
Conjugated diene rubbers such as BR and hydrogenated products thereof, styrene butadiene diene block copolymer, block copolymers such as styrene isoprene block copolymer and hydrogenated products thereof, chloroprene, urethane rubber, polyester rubber, Epichlorohydrin rubber,
Silicon rubber, ethylene propylene copolymer, ethylene propylene diene copolymer and the like can be mentioned. When weather resistance is required, a rubber-like polymer other than the conjugated diene rubber is preferable, and silicon rubber is particularly preferable in terms of moldability and the like. The hardness of the polymer elastic body is preferably 60 or less according to JIS-A, and more preferably 40 or less.

As the gel composition, hydrogel, organogel and the like can be used. From the viewpoint of the stability of the mechanical properties, an organogel containing a high-boiling organic solvent is preferred. Preferred specific examples include copolymers of acrylic (meth) acrylate and hydroxyalkyl (meth) acrylate, and silicone gel. Among them, silicone gel is more preferable from the viewpoint of stability to use environment. Since the gel composition is soft and easily deformed even with a small load, it is possible to favorably absorb the warpage of the object to be connected (substrate to be inspected, etc.) and the surface step.

As the hollow body containing gas or liquid, a hollow body in which a fluid substance such as gas or liquid is hermetically sealed and contained in a flexible hollow body can be used. preferable. Specific examples of such a hollow body include, for example, a bag made of a resin film or a rubber-like polymer sheet, a hollow molded body of a polymer elastic body, and a fluid-encapsulated body. Can be Examples of the fluid include gases such as air and nitrogen gas, liquids such as water, oils and fats, hydrocarbons and alcohols, and various sols and gels. Of these, air and water are preferred, and so-called air pillows and water bed structures (water pillows) are preferably used.

The lamination between the layers (A), (B), and (C) can be performed by various methods such as bonding with an adhesive, thermocompression bonding, integral molding, and lamination. When laminating between the layers (A) and (B) with an adhesive, it is preferable to use a conductive adhesive as the adhesive. For example, when (B) a conductive intermediate layer is formed on one of the surfaces of the conductive elastic material layer (A), sandblasting is performed on one of the surfaces of the conductive elastic material (A) to form a polymer elastic material on the surface. Remove, exposing the metal particles to the surface. A palladium catalyst is applied to the exposed surface and copper electrolytic plating is performed to form a plating layer having a thickness of 20 μm. In the case of forming the conductor intermediate layer (B) on one of the surfaces of the elastic layer (C), an aluminum sheet having a thickness of 15 μm is fixed on an adsorption table, and cured on this to become an elastic body. A liquid silicone rubber composition is applied, degassed under reduced pressure, put in a hot press, and heat-cured at 150 ° C. for 30 minutes.
The integrated laminate of (C) can be manufactured. Further, by combining the above steps, (A), (B), (C)
Can be made into a laminated body. Also,
Each of (A), (B), and (C) may be separately prepared, and they may be overlapped with each other, or may be bonded with an adhesive if necessary. As the adhesive, a conductive adhesive is preferable between (A) and (B).

The conductive laminate of the present invention has an effect of reliably connecting to an electrode of a circuit board or the like, and is particularly useful when conducting an electrical inspection of a circuit board or the like. When an electrical inspection of a circuit board or the like is performed, the conductive laminate of the present invention, the circuit board, and the inspection apparatus can be electrically and accurately connected. Can be combined to form a circuit board inspection apparatus. FIG. 10 is a conceptual diagram showing an example of the configuration of such a circuit board inspection apparatus.
Shown in

[0031]

Next, the present invention will be described with reference to specific production examples. Production Example 1 1) Preparation of Paste A silicone rubber was used as a rubber, and a particle diameter of 10 μm in which gold was plated on the surface as conductive particles with respect to 100 parts by weight of the rubber.
500 parts by weight of nickel particles (volume fraction 33.2%)
These were blended and kneaded to obtain a composition (paste). 2) Mold treatment A 50 μm-thick resist is applied to the entire surface of the flat mold, and pattern exposure is performed to form a 50 μm-diameter dent to 100 μm.
Patterning was performed at intervals. Next, the opening of the resist was first plated with gold to a thickness of 0.5 μm, and then copper was plated to the thickness of the resist (50 μm) to produce a mold (1) as shown in FIG. 3) Molding of Conductive Rubber The composition (paste) was introduced between the mold (1) and the flat mold (2) subjected to the above treatment as shown in FIG. After crosslinking at 100 ° C. for 2 hours in a magnetic field, the flat mold (2) was removed. As a result, a molded product of a conductive rubber sheet having a thickness of 0.5 mm was obtained.

4) Production of Intermediate Conductive Layer (B) The flat surface of the conductive rubber sheet (A-1) obtained above was roughened with a sandblaster to expose gold-plated nickel particles. This surface was immersed in a paradigm catalyst solution, immersed in an electroless plating solution, and plated with copper to 1 μm.
After thickening, apply electrolytic copper plating with copper sulfate plating solution.
The intermediate conductive layer (B-1) was formed with a thickness of 0 μm.

Production of Elastic Body (C) On the intermediate conductive layer (B-1) obtained above, the liquid silicone rubber used for the preparation of the above paste is applied, and decompression and defoaming are performed for 30 minutes. After finishing, mold with flat surface (2)
, And introduced into a hot press apparatus, and kept at 100 ° C. for 30 minutes to cure the silicone rubber. As a result, an elastic layer (C-1) having a thickness of 3 mm was formed on (B-1), and the three layers (A-1), (B-1) and (C-1) were integrated. A laminate was obtained.

6) Removal of Surface Residue The mold (1) and the mold (2) were removed, and the molded product was taken out. As a result, the thickness of the metal protrusion of copper coated with gold on the surface was integrated with the conductive rubber. 0.5 mm conductive rubber sheet (A-
1), an intermediate conductive layer (B-1) made of a copper metal layer having a thickness of 20 μm, and an elastic body layer (C-1) made of a silicone rubber having a thickness of 3 mm were obtained. . In order to remove the resist residue remaining on the surface of the molded product, the molded product was immersed in a developer, washed with water and dried to obtain a conductive laminate 1 shown in FIG.

Production Example 2 Molding of Conductive Rubber Sheet Production Example 1 using the paste and the mold used in Production Example 1.
A conductive rubber sheet was formed by the same manufacturing process as in the above.
The molds (1) and (2) were removed. As a result, a molded product of a conductive rubber sheet having a thickness of 0.5 mm (A-
2) was obtained. 2) Removal treatment of surface residue In order to remove the resist residue remaining on the surface of the molded product (A-2), the molded product is immersed in a developer, washed with water, and dried to form a copper metal having a gold-coated surface. A conductive rubber sheet (A-2) in which the projections were integrated with the conductive rubber was obtained.

Intermediate conductive layer (B-2) An aluminum sheet having a thickness of 15 μm was used. Elastic layer (C-2) A water bed structure containing water in a bag made of polyethylene resin was used. Formation of Laminate The conductive rubber sheet (A-2) obtained above and the intermediate conductive layer (B-2) are used as an adhesive to form a conductive adhesive DA652.
Using 0 (manufactured by Toray Dow Corning Silicone Co., Ltd.), thermosetting bonding was performed at 150 ° C. for 1 hour. further,
The intermediate conductive layer (B-2) and the elastic layer (C-2) are cured and bonded at room temperature using an epoxy-based adhesive.
2), a laminate 2 composed of (B-2) and (C-2) was obtained.

Comparative Production Example In Production Example 2, the intermediate conductive layer (B-2) was not used.
A laminate 3 consisting only of (A-2) and (C-2) was obtained.

Electrical Inspection of Circuit Board Example 1, Comparative Example 1 Using the conductive laminates 1, 2 and 3 produced in the above production example, as shown in FIG. An electrical continuity test of the inspection object was performed using a circuit board) and an inspection jig.

The object to be inspected had a surface having electrodes of 100 μm square arranged at a pitch of 250 μm and arranged in a 200-point lattice. Each electrode on this surface is covered with a resist insulating layer having a 200 μm square opening around the electrode, and the height of the resist insulating layer and the electrode is set to 10 μm higher than the electrode using a multilayer wiring board. Was.

The results of the above inspection are shown in the following table.

[0041]

[Table 1] ● Excellent conduction ○ Good conduction × Not conductive

Example 2 In the same manner as in the above-described Example 1, a laminate corresponding to each of the substrates to be inspected having the following shapes was manufactured, and the inspection was performed in the same manner as in the Example 1. Conductivity was obtained. In order to correspond to the irregularities on the surface of the substrate to be inspected shown in FIG.
Conductive Laminate with Protrusions Formed on Conductive Rubber Sheet (A) As shown in FIG. 8, the surface of the substrate to be inspected has a step, and each step has an inspection electrode. As shown in FIG. 9, the conductive rubber sheet (A) has a flat conductive surface so as to correspond to the substrate to be inspected having a flat surface. Laminate

[0043]

According to the conductive laminate of the present invention, the periphery of the microelectrode of the circuit board to be subjected to the electrical continuity test is surrounded by an insulating layer such as a photoresist, and the electrode is located at a lower position. Even if it is, since the surface of the conductive rubber sheet has minute metal protrusions, stable electrical connection is possible,
In addition, the conductivity in the lateral direction is extremely improved by the conductor intermediate layer, and the electrical continuity test can be reliably performed. In addition, by providing the conductive elastic layer, the conductive intermediate layer can be protected, and irregularities can be formed on the conductive elastic layer according to the surface condition of the object to be connected. Connection is possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a conventional technique for inspecting electrical continuity of a circuit board.

FIG. 2 is a schematic view showing a relationship between a conductive rubber sheet and an object to be inspected in a conventional technique.

FIG. 3 is a schematic view showing a laminate of the present invention.

FIG. 4 is a schematic view showing a manufacturing process of the laminate of the present invention.

FIG. 5 is a schematic view showing a manufacturing process of the laminate of the present invention.

FIG. 6 is a schematic view showing a conductive elastic body of the laminate of the present invention.

FIG. 7 is a schematic diagram showing the relationship between the laminate of the present invention and an inspection object.

FIG. 8 is a schematic diagram showing the relationship between the laminate of the present invention and a test object.

FIG. 9 is a schematic diagram showing the relationship between the laminate of the present invention and an inspection object.

FIG. 10 is a schematic view showing a method for inspecting electrical characteristics of an object to be inspected using the laminate of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive rubber sheet 2 pin probe 3 tester 4 test object (multilayer wiring board) 5 resist layer 6 electrode of test object 7 elastic layer 8 conductive intermediate layer 9 conductive elastic layer 10 conductive laminate 11 conductive protrusion Reference Signs List 12 resist layer 13 mold (1) 14 mold (2) 15 rubber 16 conductive particles 17 paste 18 silicone rubber sheet 19 aluminum foil 20 conductive elastic layer with projection 21 copper foil sheet 22 conductive elastic layer with step 23 Cavity substrate 24 Gel-like substance or water bed 25 Aluminum sheet 26 Conductive elastic layer 27 Inspection device press part (upper) 28 Anisotropic conductivity inspection jig 29 Fixing pin 30 Rubber head 31 Inspection device press part (lower)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G01R 31/02 G01R 31/02 H01L 21/66 H01L 21/66 DF term (reference) 2G011 AA16 AA21 AB06 AB08 AC14 AE01 2G014 AA13 AB59 AC06 AC10 4F100 AB01B AB16 AB17 AB25 AK01C AK52 AN00A AR00A AR00B AR00C BA03 BA07 BA10A BA10C CA21A DD01A DE01A DJ02C EH46 EH71 GB43 JG01 JG01A JG01B JK07A JK07C JL00 JM01A08M08A

Claims (8)

[Claims] 1. A conductive laminate comprising (A) a conductive elastic layer, (B) a conductive intermediate layer other than (A), and (C) an elastic layer other than (A). 2. The conductive laminate according to claim 1, wherein (A) the conductive elastic layer is formed by blending conductive particles in a polymer having elasticity. 3. The conductive elastic layer (A) is composed of conductive particles and a rubber-like polymer, and the conductive particles have a volume fraction of 5%.
2. The conductive laminate according to claim 1, wherein the amount is from 50% to 50%. 3. 4. The conductive laminate according to claim 1, wherein (A) the conductive elastic layer is an anisotropic conductive rubbery polymer. 5. The conductive laminate according to claim 1, wherein (A) the surface of the conductive elastic layer has irregularities corresponding to irregularities of the connection object. 6. The conductive laminate according to claim 1, wherein (B) the conductive intermediate layer is a thin metal layer. 7. The conductive laminate according to claim 1, wherein the elastic layer is at least one selected from a polymer elastic body, a gel composition, and a hollow body containing a gas or a liquid. . 8. A circuit board inspection apparatus, wherein the conductive laminate according to claim 1 is electrically connected to a circuit board and an inspection apparatus.