JP2009140866A - Anisotropic conductivity member and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anisotropic conductive member which is improved by leaps and bounds in the installation density of conductive path and is used as an electric connection member and an inspection connector or the like of an electronic component such as a semiconductor element, even at the present time when high integration is further advanced, and its manufacturing method. <P>SOLUTION: The anisotropic conductive member includes a plurality of conductive paths made of a conductive member penetrated in thickness direction of the insulating substrate in an insulating substrate, and one end of each conductive path is exposed or protrudes on one surface of the insulating substrate, and the other end of each conductive path is exposed or protrudes on the other surface of the insulating substrate. The density of the conductive paths is 2 millions pieces/mm<SP>2</SP>or more. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an anisotropic conductive member and a method for manufacturing the same.

  An anisotropic conductive member is inserted between an electronic component such as a semiconductor element and a circuit board, and electrical connection between the electronic component and the circuit board can be obtained simply by applying pressure. It is widely used as an electrical connection member or a connector for inspection when performing functional inspection.

In particular, the downsizing of electronic connection members such as semiconductor elements is remarkable, and it is difficult to further reduce the diameter of the wire in a method of directly connecting a wiring board such as conventional wire bonding. As a result, it has become difficult to ensure sufficient connection stability.
Therefore, in recent years, anisotropic conductive members of a type in which a conductive member penetrates in a film of an insulating material or a type in which a metal ball is arranged have been attracting attention.

In addition, the inspection connector such as the semiconductor element, when the electronic component such as the semiconductor element is mounted on the circuit board and the function inspection is performed, when the electronic component is defective, the circuit board is also disposed of together. It is used to avoid the problem of a large monetary loss.
That is, an electronic component such as a semiconductor element is brought into contact with the circuit board through an anisotropic conductive member at a position similar to that at the time of mounting, and a function test is performed, so that the electronic component is not mounted on the circuit board. Functional inspection can be performed, and the above problems can be avoided.

  As such an anisotropic conductive member, Patent Document 1 states that “in a film substrate made of an adhesive insulating material, a plurality of conductive paths made of a conductive material are insulated from each other and the film substrate is made. The average of the maximum length between two points on the outer periphery of the shape in the cross section of the conduction path parallel to the longitudinal direction of the film substrate is 10 to 30 μm, and the distance between adjacent conduction paths Is an anisotropic conductive film characterized in that it is 0.5 to 3 times the average of the maximum length.

  Patent Document 2 states that “in a film base material made of an insulating resin, a plurality of conductive paths are insulated from each other, penetrate the film base material in the thickness direction, and are arranged in a staggered arrangement. An anisotropic conductive film, characterized in that the distance between the conductive paths between adjacent conductive path arrays is smaller than the distance between the conductive paths in the conductive path array. " Is disclosed.

As a method for producing such an anisotropic conductive film, Patent Documents 1 and 2 describe that a thin wire of an anisotropic conductive material is sandwiched on an insulating film, and then integrated by heating and pressing, and scribed in the thickness direction. A method is disclosed.
Patent Document 3 discusses a method of manufacturing an anisotropic conductive film by producing a conductive column by electroforming using a resist and a mask, and pouring an insulating material into the column and curing it. .

On the other hand, in Patent Document 4, “a holding body made of an electrically insulating material and a plurality of conductive members provided in an insulated state in the holding body, one end of each of the conductive members is the holding In the method of manufacturing an electrical connection member that is exposed on one surface of the body and the other end of each conductive member is exposed on the other surface of the holding body,
A high energy beam is irradiated from a side of the insulating layer to a base material having a base and an insulating layer serving as the holding body provided by being laminated on the base. A first step of removing a part of the base and forming a plurality of holes in the base material;
A second step of filling a plurality of formed holes with a surface of the insulating layer or projecting from the surface and filling a conductive material to be the conductive member; and a third step of removing the substrate A method for manufacturing an electrical connection member, comprising: And various materials such as a polyimide resin, an epoxy resin, and a silicon resin have been studied as an insulating layer.

By the way, in recent years, as electronic components such as semiconductor elements are further integrated, the size of electrodes (terminals) is reduced, the number of electrodes (terminals) is increased, and the distance between terminals is also reduced. It is coming. In addition, electronic components having a surface structure in which the surface of each terminal arranged in a large number at a narrow pitch is located deeper than the surface of the main body have also appeared.
For this reason, it is necessary to arrange the conduction paths in the anisotropic conductive member to have a smaller outer diameter (thickness) and to be arranged at a narrow pitch so as to cope with such electronic components.
However, in the method for manufacturing the anisotropic conductive film and the electrical connection member described in Patent Documents 1 to 4 and the like, it is very difficult to reduce the size of the conduction path.

JP 2000-012619 A JP 2005-085634 A JP 2002-134570 A Japanese Patent Laid-Open No. 03-182081

  Therefore, the present invention dramatically improves the installation density of the conductive paths, and can be used as an electrical connection member or an inspection connector for an electronic component such as a semiconductor element even at the present time when the integration is further advanced. An object is to provide an anisotropic conductive member and a manufacturing method thereof.

As a result of earnest research to achieve the above-mentioned object, the present inventor made a dramatic increase in the density of the conductive path by using an insulating base material made of a polymer material and having a phase-separated structure standing in the depth direction. The present invention has been completed.
That is, the present invention provides the following (1) to (4).

(1) In the insulating base material, a plurality of conductive paths made of conductive members penetrate the insulating base material in the thickness direction while being insulated from each other, and one end of each of the conductive paths is insulated. An anisotropic conductive member that is exposed or protruded on one surface of the conductive base material and is provided with the other end of each conduction path exposed or protruded on the other surface of the insulating base material,
An anisotropic conductive member, wherein the density of the conduction path is 2 million pieces / mm ² or more.

  (2) The anisotropic conductive member according to (1), wherein the length (length / thickness) of the center line of the conduction path with respect to the thickness of the insulating base material is 1.0 to 1.2. .

(3) A method for producing an anisotropic conductive member for producing the anisotropic conductive member according to (1) or (2) above, wherein at least
A penetration treatment step of forming a through hole in the insulating member; and
An anisotropic conductive member comprising, after the penetrating treatment step, a metal filling step of filling the inside of the penetrated hole in the obtained insulating member with the conductive member to obtain the anisotropic conductive member. Manufacturing method.

  (4) The penetration process step is a process of removing a portion related to the forested phase separation structure on an insulating member made of a polymer material and having a phase separation structure forested in the depth direction. The method for producing an anisotropic conductive member according to the above (3).

  As shown below, according to the present invention, the installation density of conduction paths has been dramatically improved, and electrical connection members and inspection connectors for electronic components such as semiconductor elements have been developed even at a higher level of integration. An anisotropic conductive member that can be used as a manufacturing method and a method for manufacturing the same can be provided.

Further, the anisotropic conductive member of the present invention has a large number of conduction paths joined to the electrode (pad) portion of the electronic component, and the pressure is dispersed, so that damage to the electrode can be reduced. . In addition, since many conduction paths are joined (contacted) to a single electrode, even if an abnormality occurs in a part of the conduction path, the influence on the overall conductivity confirmation is extremely small. Furthermore, the load for positioning the circuit board for evaluation can be greatly reduced.
Furthermore, the method for manufacturing an anisotropic conductive member of the present invention is very useful because the anisotropic conductive member of the present invention can be efficiently manufactured.

Below, the anisotropic conductive member of this invention and its manufacturing method are demonstrated in detail.
In the anisotropic conductive member of the present invention, the insulating base material has a plurality of conductive paths made of the conductive member penetrating the insulating base material in the thickness direction while being insulated from each other. An anisotropic conductive member provided with one end of the conductive path exposed or protruded on one surface of the insulating base material and the other end of each conductive path exposed or protruded on the other surface of the insulating base material Because
It is an anisotropic conductive member whose density of the said conduction path is 2 million pieces / mm < ² > or more.
Next, the anisotropic conductive member of the present invention will be described with reference to FIG.

FIG. 1 is a simplified view showing an example of a preferred embodiment of the anisotropic conductive member of the present invention, FIG. 1 (A) is a front view, and FIG. 1 (B) is a section line of FIG. 1 (A). It is sectional drawing seen from Ib-Ib.
An anisotropic conductive member 1 of the present invention includes a plurality of conductive paths 3 made of an insulating substrate 2 and a conductive member.
The conductive paths 3 are insulated from each other so that the length in the axial direction is not less than the length (thickness) in the thickness direction Z of the insulating base material 2 and the density is not less than 2 million pieces / mm ^2. It is provided through the insulating substrate 2.
In addition, the conductive path 3 is in a state in which one end of each conductive path 3 is exposed on one surface of the insulating base material 2 and the other end of each conductive path 3 is exposed on the other surface of the insulating base material 2. 1B, one end of each conduction path 3 protrudes from one surface 2a of the insulating base material 2, and the other end of each conduction path 3 is the other side of the insulating base material 2, as shown in FIG. It is preferable to be provided in a state protruding from the surface 2b. That is, it is preferable that the both ends of each conduction path 3 have the protruding portions 4a and 4b protruding from 2a and 2b which are the main surfaces of the insulating base material.
Further, in this conduction path 3, at least a portion in the insulating base material 2 (hereinafter also referred to as “in-base conduction portion 5”) is substantially parallel to the thickness direction Z of the film base material 2 (in FIG. 1). Are preferably parallel to each other. Specifically, the length (length / thickness) of the center line of the conduction path with respect to the thickness of the insulating base material is preferably 1.0 to 1.2, and preferably 1.0 to 1.1. It is more preferable that
Next, materials, dimensions, formation methods, and the like will be described for each of the insulating base material and the conduction path.

[Insulating substrate]
The insulating base material constituting the anisotropic conductive member of the present invention may be either organic or inorganic, but is preferably a material having an electrical resistivity of 1 × 10 ³ Ω · cm or more, A material of 1 × 10 ⁵ Ω · cm or more is more preferable, and a material of 1 × 10 ⁷ Ω · cm or more is particularly preferable.
In addition, the insulating base material is preferably an organic material such as a polymer material because the insulating member can be easily subjected to a penetration treatment in the method for producing an anisotropic conductive member of the present invention described later. A block copolymer material that can form a separation structure is particularly preferable.
Below, the block copolymer which is a raw material suitable as the said insulating base material is explained in full detail.

In the present invention, the block copolymer refers to a block copolymer in which the hydrophilic polymer component (A) and the hydrophobic polymer component (B) are linked by a covalent bond.
Here, the polymer component (A) and the polymer component (B) have opposite chemical and physical properties and are incompatible with each other.

  In the present invention, the block copolymer is not limited in the binding order of the hydrophilic polymer chain A composed of the polymer component (A) and the hydrophobic polymer chain B composed of the polymer component (B), The molecular weight distribution is preferably 1.3 or less.

  Here, examples of the polymer component (A) include poly (ethylene oxide), poly (propylene oxide), poly (vinyl alcohol), poly (acrylic acid), poly (methacrylic acid), poly (acrylamide), oligo ( Ethylene oxide); crown ether, cryptand; poly (methacrylate) or poly (acrylate) having a sugar chain in the side chain, and specifically poly (ethylene oxide) methyl ether.

  On the other hand, examples of the polymer component (B) include poly (methacrylate), poly (acrylate), poly (styrene), vinyl polymer having a mesogen side chain, a long alkyl side chain, or a hydrophobic side chain. It is done.

Examples of the mesogen side chain include those having one or more structural units represented by the following formula.
_{^{E- (Y 1 -F) n -Y}} 2 -G

In the formula, E, F and G may be the same or different and are respectively 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, naphthalene-2,6- Diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 1,4-bicyclo [2.2.2] octylene, 1,3-dioxane-2 , 5-diyl, pyridine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl or pyrimidine-2,5-diyl.
Y ¹ and Y ² may be the same or different and are each a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —C (═O) O. -, - OC (= O) -, - C≡C -, - CH = CH -, - CF = CF -, - (CH 2) 4 -, - CH 2 CH 2 CH 2 O -, - OCH 2 CH ₂ CH ₂ —, —CH═CH—CH ₂ CH ₂ —, —CH ₂ CH ₂ —CH═CH—, —N═N—, —CH═CH—C (═O) O— or —OC (= O) —CH═CH—.
N represents an integer of 0 to 3.

The long-chain alkyl side chain refers to an alkyl side chain having 6 to 22 carbon atoms.
Examples of the hydrophobic side chain include an aliphatic side chain.

  Furthermore, in this invention, it is preferable that the molecular weights of the said block copolymer are 5000-100000, and it is more preferable that it is 10000-50000.

  Specific examples of such block copolymers include those represented by the following chemical formula.

（式中、ｍおよびｎは同一であっても異なっていてもよく、それぞれ５〜５００の整数を表し、ａは１〜２２の整数を表し、Ｒは水素原子または炭素数１〜２２のアルキル基を表す。）

Wherein m and n may be the same or different and each represents an integer of 5 to 500, a represents an integer of 1 to 22, and R represents a hydrogen atom or an alkyl having 1 to 22 carbon atoms. Represents a group.)

Moreover, when such a block copolymer is dissolved in a solvent to form a film, a microphase separation structure is formed based on the repulsive interaction between the hydrophilic polymer chain A and the hydrophobic polymer chain B. Is done.
Therefore, an insulating member made of a polymer material and having a phase-separated structure in the depth direction used in the method for producing an anisotropic conductive member of the present invention to be described later is, for example, the above block copolymer on a substrate. The film obtained by applying and drying can be obtained by subjecting the film to heat treatment or application of electrolysis.

  As the substrate, a substrate made of a hydrophobic substance or a substrate whose surface has been subjected to a hydrophobic treatment is preferably used. Specifically, substrates such as polyester, polyimide, mica plate, silicon wafer, quartz plate, glass plate and the like, and substrates obtained by subjecting the surface of these substrates to hydrophobic treatment such as carbon deposition treatment or silylation treatment are preferably used. It is done.

Examples of the method of applying the block copolymer on the substrate include a method of applying a solution obtained by dissolving the block copolymer in an appropriate solvent by spin coating, casting, dip, bar coating, or the like. .
Specific examples of the solvent include benzene, toluene, xylene, chloroform, dichloromethane, tetrahydrofuran, dioxane, carbon tetrachloride, ethylbenzene, propylbenzene, ethylene dichloride, and methyl chloride.
Moreover, it is preferable that the density | concentration of the said block copolymer dissolved in the said solvent is about 0.1-5 mass%.
Furthermore, the film thickness of the film obtained by applying the block copolymer on the substrate and drying is preferably about 30 nm to about 10 μm.

The said heat processing can be normally performed in the following procedures.
When the film obtained by applying the block copolymer on the substrate is heated at a temperature equal to or higher than the melting point, the hydrophilic polymer chain A composed of the hydrophilic polymer (A) is oriented in a direction substantially perpendicular to the film surface. Take the structure.
Here, the melting point can be measured by DSC (differential scanning calorimetry), and the melting point of the block copolymer is usually 120 to 140 ° C.

On the other hand, the above-mentioned electric field application can be usually performed by the following procedure.
During film formation or the film formed is placed on a substrate and heated at a temperature lower than the melting point of the block copolymer by 10 to 100 ° C., preferably 50 to 80 ° C., and at the same time, 1 × 10 ^{5 is applied to the} film. By applying an electric field of ˜3 × 10 ⁷ V / m, preferably 1 × 10 ^{5 to} 3 × 10 ⁶ V / m, the hydrophilic polymer chain A can be oriented in the electric field direction.

The electric field can be applied, for example, by bringing a minute comb-shaped electrode or a polymer-coated minute electrode close to each other, and the orientation of the phase separation structure can be controlled region-selectively depending on the mode.
Therefore, in order to obtain an insulating member having a phase separation structure that stands in the depth direction, it is preferable to apply an electric field substantially perpendicularly to the substrate.

The electric field may be a constant electric field between 1 × 10 ^{5 and} 3 × 10 ⁷ V / m, and the direction of the electric field (+/−) may be any.
Furthermore, the maximum value of the electric field is set to 1 × 10 ^{5 to} 3 × 10 ⁷ V / m, and the electric field is alternately swept in the positive direction, the negative direction, or both directions (specifically, the applied potential is swept). Also good. In this way, it is preferable to switch the direction of the electric field because the orientation becomes clearer.

The method for applying the electric field is not particularly limited. For example, a method of forming a film using the substrate as an electrode, applying an electrolytic solution on the film, and applying a desired voltage between the electrode substrate and the electrolytic solution. Etc.
The electrode substrate may be any electrode material having electrical conductivity, for example, a metal plate such as platinum, stainless steel, or gold; graphite; glass, plastic film, silicon wafer coated with indium tin oxide (ITO); It is preferable to use an ITO glass electrode substrate.
As an electrolytic solution, water or an organic solvent such as tetrahydrofuran, chloroform, dimethylsulfoxide, dimethylformamide is used as a solvent, and potassium chloride, sodium chloride, potassium bromide, sodium bromide, sodium sulfate, sodium perchlorate are used as solutes. A solution in which an electrolyte such as sodium nitrate is dissolved can be used.
Furthermore, not only a general electrochemical cell but also a special electrochemical cell that can selectively apply an electric field to a minute region using a minute electrode such as a tip of a scanning probe microscope can be used.

  The heat treatment and the electrolysis application may be performed after the block copolymer once applied is heated and solidified, or may be performed simultaneously with the application of the block copolymer on the substrate. .

In the present invention, when the block copolymer is applied onto the substrate, the inorganic ceramic fine particles, organic transition metal complex crystals, noble metal fine particles, metal oxide fine particles and the like are allowed to coexist with the block copolymer, When solidified with the treatment, depending on the properties of the fine particles, the fine particles can be aggregated in the hydrophilic portion or the hydrophobic portion of the layer structure of the block copolymer, and a film having a characteristic layer structure can be formed.
For example, magnetic iron oxide fine particles having a hydrophilic surface are dispersed in a copolymer solution, and this dispersion is applied to a slide glass, a PET film or the like, and dried at room temperature. A film having a layer structure in which the fine particles are aggregated in the hydrophilic portion can be obtained.

The block copolymer thus formed has a microphase-separated structure of a hexagonal lattice cylinder, a spherical structure, or a lamellar structure.
Further, the lattice constant serving as the structural factor depends on the molecular weights of the hydrophilic polymer chain A and the hydrophobic polymer chain B. That is, m and n in the above formula satisfy m / (m + n) = 0.1 to 0.9.

Although the manufacture example of the said insulating base material which comprises the anisotropically conductive member of this invention is shown below, this invention is not limited to this manufacture example.
[Production Example 1]
A block copolymer was synthesized in which poly (ethylene oxide) methyl ether (molecular weight 5000) was a hydrophilic polymer chain A and polymethacrylate (polymerization degree 114) having an azobenzene-containing liquid crystalline side chain was a hydrophobic polymer chain B. .
Here, the synthesis was performed by an atom transfer radical polymerization method using a copper complex as a catalyst.
The number average molecular weight of the obtained block copolymer was 28100, Mw / Mn = 1.08, the polymethacrylate (MA) content was 82% by weight, and the melting point was 120 ° C.
The obtained block copolymer is shown in the following chemical formula.

（式中、ａは９、Ｒはｎ−ブチル基、ｍは１１４、ｎは４７を表す。）

(In the formula, a represents 9, R represents an n-butyl group, m represents 114, and n represents 47.)

Subsequently, the block copolymer obtained above was dissolved in toluene so that it might become 3 mass%, and the copolymer solution was prepared.
0.1 ml of this copolymer solution was dropped on 1 cm ² of highly oriented graphite, ITO glass electrode substrate, and ITO polyethylene terephthalate film.
Immediately after the dropping, the sample bottle containing 30 ml of toluene was transferred to a desiccator having an internal volume of 2 L and allowed to stand for 5 hours.
Subsequently, the obtained cast film was heated at a temperature of 50 to 80 for 5 to 48 hours to obtain a block copolymer thin film (film thickness: 15 μm) subjected to microphase separation.

In the forested part of the obtained block copolymer thin film separated by microphase, only the forested part is appropriately removed with a solvent, thereby forming an insulating substrate (see FIG. 2).
Here, FIG. 2 (A) is a schematic diagram of a block copolymer thin film separated by microphase (reference numeral 101: block copolymer thin film (insulating member), reference numeral 102: hydrophobic polymer chain B, reference numeral 103: FIG. 2B is a schematic diagram of the insulating base material (reference numeral 104: insulating base material, reference numeral 105: through-hole).
Specific examples of the solvent include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2- Examples include propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene.

[Conduction path]
The conduction path constituting the anisotropic conductive member of the present invention is made of a conductive member.
The conductive member is not particularly limited as long as the electrical resistivity is 10 ³ Ω · cm or less, and specific examples thereof include gold (Au), silver (Ag), copper (Cu), aluminum (Al ), Magnesium (Mg), nickel (Ni), indium-doped tin oxide (ITO), and the like.
Among these, from the viewpoint of electrical conductivity, copper, gold, aluminum, and nickel are preferable, and copper and gold are more preferable.
Further, from the viewpoint of cost, it is more preferable that only the surfaces of the conductive path exposed from both surfaces of the insulating substrate or the surfaces of the protruding surfaces (hereinafter also referred to as “end faces”) are formed of gold.

In the present invention, the conducting path is columnar, and the diameter (portion represented by reference numeral 8 in FIG. 1B) is preferably 5 to 500 nm, more preferably 20 to 400 nm. 40 to 200 nm is more preferable, and 50 to 100 nm is particularly preferable. If the diameter of the conduction path is within this range, a sufficient response can be obtained when an electric signal is passed, so the anisotropic conductive member of the present invention is used as an electrical connection member or inspection connector for electronic components. It can be used more suitably.
Further, as described above, the length (length / thickness) of the center line of the conduction path with respect to the thickness of the insulating base material is preferably 1.0 to 1.2, and 1.0 to 1. 1 is more preferable. When the length of the center line of the conduction path with respect to the thickness of the insulating substrate is within this range, it can be evaluated that the conduction path has a straight pipe structure, and a one-to-one response is obtained when an electric signal is passed. Since it can obtain reliably, the anisotropically conductive member of this invention can be used more suitably as a connector for an inspection of an electronic component, or an electrical connection member.

  Moreover, in this invention, when the both ends of the said conduction path protrude from both surfaces of the said insulating base material, the protruded part (The part represented by code | symbol 4a and 4b in FIG. 1 (B). The height of the “bump” is preferably 10 to 100 nm, and more preferably 10 to 50 nm. When the height of the bump is within this range, the bondability with the electrode (pad) portion of the electronic component is improved.

In the present invention, the conductive paths exist in a state of being insulated from each other by the insulating base material, and the density thereof is 2 million pieces / mm ² or more and 10 million pieces / mm ² or more. Of 50 million / mm ² or more, more preferably 100 million / mm ² or more.
The anisotropic conductive member of the present invention is used as a connector for inspection of electronic parts such as semiconductor elements or an electrical connection member even at the present time when the high integration is further advanced because the density of the conductive path is in this range. can do.

  In the present invention, the distance between the centers of adjacent conductive paths (a portion represented by reference numeral 9 in FIG. 1; hereinafter also referred to as “pitch”) is preferably 20 to 500 nm, and preferably 40 to 200 nm. Is more preferable, and it is still more preferable that it is 50-140 nm. When the pitch is within this range, it is easy to balance the conduction path diameter and the width between the conduction paths (insulating partition wall thickness).

In the present invention, the conductive path can be manufactured, for example, by filling a metal, which is a conductive member, into a through hole formed in the insulating member.
Here, the processing step of filling the metal will be described in detail in the method for manufacturing the anisotropic conductive member of the present invention described later.

  As described above, the anisotropic conductive member of the present invention has a thickness of the insulating substrate of 1-1000 μm, preferably 30-300 μm, and a diameter of the conductive path of 5-500 nm, preferably 20 It is preferable that the thickness is ˜400 nm because high insulation can be maintained and conduction can be confirmed at high density.

The method for producing an anisotropic conductive member of the present invention (hereinafter also simply referred to as “the method of production of the present invention”) is a method for producing an anisotropic conductive member for producing the anisotropic conductive member of the present invention described above. At least,
A penetration treatment step of forming a through hole in the insulating member; and
An anisotropic conductive member comprising, after the penetrating treatment step, a metal filling step of filling the inside of the penetrated hole in the obtained insulating member with the conductive member to obtain the anisotropic conductive member. It is a manufacturing method.
Next, each processing step in the production method of the present invention will be described in detail.

[Penetration process]
The penetration process step is a step of forming a through hole in the insulating member.
Here, the insulating member is a member in a state including a portion corresponding to a conduction path in the anisotropic conductive member of the present invention, and as the material thereof, like the insulating base material, a polymer material or the like is used. The organic material is preferably a block copolymer polymer material capable of forming a phase separation structure.

  The method of making a through-hole in the insulating member is not particularly limited because it differs depending on the insulating member, but in the case of a block copolymer polymer material that forms a phase separation structure, the above-described phase separation structure is a forested structure. There is a method for removing such a portion (see FIG. 2). In the case of an insulating base material that is another organic material or inorganic material, a cutting technique such as ion milling or lithography can be used.

  By this penetration process step, the insulating substrate 20 shown in FIG. 3A is obtained.

[Metal filling process]
The metal filling step is a step of obtaining the anisotropic conductive member by filling a metal which is a conductive member into the inside of the penetrated hole in the obtained insulating base material after the penetrating treatment step. is there.
Here, the metal to be filled constitutes a conduction path of the anisotropic conductive member, and is the same as that described in the anisotropic conductive member of the present invention.

In the production method of the present invention, an electrolytic plating method or an electroless plating method can be used as the metal filling method.
Here, in the conventionally known electroplating method used for coloring or the like, it is difficult to selectively deposit (grow) a metal in a hole at a high aspect. This is presumably because the deposited metal is consumed in the holes and the plating does not grow even if electrolysis is performed for a certain time or longer.

For this reason, in the production method of the present invention, when the metal is filled by the electrolytic plating method, it is necessary to provide a rest time during pulse electrolysis or constant potential electrolysis. The rest time is required to be 10 seconds or more, and preferably 30 to 60 seconds.
It is also desirable to add ultrasonic waves to promote stirring of the electrolyte.
Furthermore, the electrolysis voltage is usually 20 V or less, preferably 10 V or less, but it is preferable to measure the deposition potential of the target metal in the electrolytic solution to be used in advance and perform constant potential electrolysis within the potential of +1 V. In addition, when performing constant potential electrolysis, what can use cyclic voltammetry together is desirable, and potentiostat apparatuses, such as Solartron, BAS, Hokuto Denko, IVIUM, etc., can be used.

A conventionally known plating solution can be used as the plating solution.
Specifically, when copper is precipitated, an aqueous copper sulfate solution is generally used, but the concentration of copper sulfate is preferably 1 to 300 g / L, more preferably 100 to 200 g / L. preferable. Moreover, precipitation can be promoted by adding hydrochloric acid to the electrolytic solution. In this case, the hydrochloric acid concentration is preferably 10 to 20 g / L.
In addition, when gold is deposited, it is desirable to perform plating by alternating current electrolysis using a sulfuric acid solution of tetrachlorogold.

  In the electroless plating method, it takes a long time to completely fill the through-hole with a high aspect with the metal. Therefore, in the manufacturing method of the present invention, it is desirable to fill the metal by the electrolytic plating method.

  By this metal filling step, the anisotropic conductive member 21 shown in FIG. 3B is obtained.

[Surface smoothing]
In the manufacturing method of this invention, it is preferable to comprise the surface smoothing process process which smooth | blunts the surface and a back surface by a chemical mechanical polishing process after the said metal filling process.
By performing a chemical mechanical polishing (CMP) process, it is possible to smooth the front and back surfaces after metal filling and to remove excess metal attached to the surface.
For the CMP treatment, CMP slurry such as PANANERLITE-7000 manufactured by Fujimi Incorporated, GPX HSC800 manufactured by Hitachi Chemical Co., Ltd., CL-1000 manufactured by Asahi Glass (Seimi Chemical Co., Ltd.), or the like can be used.

[Trimming]
In the manufacturing method of the present invention, it is preferable that a trimming process is provided after the surface smoothing process when the metal filling process or the CMP process is performed.
In the trimming process, when the metal filling process or the CMP process is performed, after the surface smoothing process, only the insulating base material on the surface of the anisotropic conductive member is partially removed to project the conduction path. It is a process.
Here, the trimming process can be performed under the same processing conditions as the oxide film dissolution process (E) described above as long as the metal constituting the conduction path is not dissolved. In particular, it is preferable to use phosphoric acid that can easily control the dissolution rate.
By this trimming step, the anisotropic conductive member 21 shown in FIG. 3C is obtained.

[Electrodeposition processing]
In the manufacturing method of the present invention, the same or different conductive metal is further deposited only on the surface of the conductive path 3 shown in FIG. 3B instead of the trimming process or after the trimming process. An electrodeposition treatment step may be included (FIG. 3D).
Specific examples of the electrodeposition treatment include electroless plating treatment.
Here, the electroless plating treatment is a step of immersing in an electroless plating treatment solution (for example, a solution obtained by appropriately mixing a noble metal-containing treatment solution having a pH of 1 to 9 and a reducing agent treatment solution having a pH of 6 to 13). is there.

  In the manufacturing method of the present invention, the trimming process and the electrodeposition process are preferably performed immediately before the anisotropic conductive member is used. It is preferable to perform these treatments immediately before use because the metal of the conduction path constituting the bump portion is not oxidized until just before use.

Example 1
(A) Penetration processing step The block copolymer thin film separated by the microphase produced by the method shown in Production Example 1 described above is immersed in ethylene dichloride for 15 minutes, and only the forest stand is removed, whereby the insulating base material is removed. Produced.

(B) Metal Filling Treatment Step Next, a copper electrode was brought into close contact with one surface of the structure after the heat treatment, and electroplating was performed using the copper electrode as a cathode and platinum as a positive electrode.
Using a mixed solution of copper sulfate / sulfuric acid / hydrochloric acid = 200/50/15 (g / L) as an electrolyte while maintaining the temperature at 25 ° C., and carrying out constant-voltage pulse electrolysis, the through-hole is filled with copper. The manufactured structure (anisotropic conductive member) was manufactured.
Here, the constant voltage pulse electrolysis was performed by using a plating apparatus manufactured by Yamamoto Sekin Co., Ltd., using a power source (HZ-3000) manufactured by Hokuto Denko Co., Ltd., and performing cyclic voltammetry in the plating solution to confirm the deposition potential. Thereafter, the potential on the film side was set to -2V. The pulse waveform of constant voltage pulse electrolysis was a rectangular wave. Specifically, the electrolysis treatment of one electrolysis time of 60 seconds was performed five times with a 40-second rest period between each electrolysis treatment so that the total electrolysis treatment time was 300 seconds.
When the surface after filling with copper was observed with FE-SEM, it was in a shape that partially overflowed from the surface of the insulating base material.

(C) Surface smoothing process Next, the CMP process was performed to the surface and back surface of the structure with which copper was filled.
As the CMP slurry, PANANERITE-7000 manufactured by Fujimi Incorporated was used.

(D) Trimming treatment Next, the structure after the CMP treatment was immersed in toluene for 1 hour, and a part of the insulating base material was selectively dissolved, thereby projecting a copper cylinder as a conduction path.

Subsequently, it was washed with water and dried, and then observed with an FE-SEM.
As a result, as shown in Table 1 below, the height of the protruding portion (bump height) of the conductive path is 10 nm, the diameter of the conductive path as the electrode size is 60 nm, and the thickness of the member is 15 μm. It was confirmed that. Moreover, it confirmed that the length (length / thickness) of the centerline of the conduction path with respect to the thickness of a member was 1.02.

(Comparative Example 1)
As Comparative Example 1, an example corresponding to the example described in Patent Document 3 (Japanese Patent Laid-Open No. 2002-134570) was performed.

Specifically, first, as shown in FIG. 4A, a resist layer (film) 42 having a uniform thickness of 150 μm is formed on a rectangular copper substrate 41 having a thickness of 0.5 mm × width of 30 mm × length of 30 mm. Formed.
As the resist material, polymethyl methacrylate resin (PMMA resin) was used, and after coating film formation, drying was performed at room temperature for 4 hours.

Next, as shown in FIG. 4B, a mask (made by Karlsruhe, Germany) 43 in which circles having a diameter of 20 μm are arranged in a finely packed manner with a pitch of 40 μm is stacked on the copper substrate 41, and vertically upward. X-ray 44 was irradiated, and the resist film portion not shielded by the mask 43 was exposed to X-rays.
Here, synchrotron radiation X-rays with excellent resist side wall surface shape accuracy were used.

  Next, as shown in FIG. 4C, a porous structure with an aspect ratio ((length / diameter) value of 10) is formed by dissolving and removing the X-ray exposed portion of the resist film by development. A mother mold M having the fine-structure resist film 45 was formed.

  Next, as shown in FIG. 4D, a nickel conductive fine wire group 46 was formed by electroforming in the dissolution and removal portion. Electroplating was performed using a sulfamic acid bath as the plating solution 47, using the nickel electrode as the positive electrode and the copper substrate as the negative electrode.

  After the electroforming process, as shown in FIG. 4 (E), the remaining resist film (fine structure resist film) 45 around the formed nickel conductive fine wire group 46 is dissolved and removed, and the nickel conductive material is deposited on the copper substrate 41. A substrate V on which the fine wire group 46 was formed was obtained.

  Next, the substrate V is accommodated in a mold, and as shown in FIG. 4F, a sheet-like base material 48 (silicone resin in this example) is filled around the nickel conductive fine wire group 46, By curing this, a sheet-like base material made of silicone resin was produced on the copper substrate.

  Next, the anisotropic conductive film 49 as shown in FIG. 4 (G) was produced by removing the copper substrate from the above produced material and further trimming the front and back surfaces with an excimer laser. In this example, the thickness of the silicone resin layer was about 100 μm, and the height of the protruding portion (bump height) of the conductive portion was 10 μm on average. In the obtained anisotropic conductive film 49, the exposed end portions of each conductive fine wire were polished and sharpened, and the end portions were plated with gold in order to lower the electric resistance.

  Further, as a result of observation by FE-SEM, as shown in Table 1 below, the height of the protruding portion of the conductive path (bump height) is 10 μm, and the diameter of the conductive path as the electrode part size is 20 μm. I confirmed that there was. Furthermore, it was confirmed that the length (length / thickness) of the center line of the conduction path with respect to the thickness of the anisotropic conductive film was 1.05.

The shapes of the anisotropic conductive members (films) obtained in Example 1 and Comparative Example 1 are shown in Table 1 below.
Here, the period refers to the distance (pitch) between the centers of the conductive paths, and the surface of the anisotropic copper conductive member (film) obtained is photographed by FE-SEM (magnification 50000 times) and measured at 50 points. The average value.
Further, as shown in FIG. 5, the density was calculated according to the following formula, assuming that there are ½ conductive electrode portions 52 in the unit cell 51 of the through holes arranged. Here, in the following formula, Pp represents a period.

Density (pieces / μm ² ) = (1/2 piece) / {Pp (μm) × Pp (μm) × √3 × (1/2)}

Using the anisotropic conductive member (film) obtained in Example 1 and Comparative Example 1, the anisotropic conductivity was evaluated.
About the electroconductivity (conductive part resistance) of a depth direction, as shown in FIG. 6, the anisotropic conductive member (film) obtained in Example 1 and the comparative example 1 is 1.5 mm x 6.0 mm large. The device 61 that has been cut is sandwiched between electrodes 62 (pitch: 10 μm) of the same size made of Au, and pressure-bonded under the conditions of 200 ° C., 0.5 MPa, 1 minute, and between G ₁ and G ₂ The electrical resistance of was measured. The smaller the resistance value, the better the anisotropic conductivity. The results are shown in Table 2.
Further, regarding the insulation in the surface direction (insulating portion resistance), the electrical resistance between G ₁ and S ₁ was measured. The larger the resistance value, the better the anisotropic conductivity. The results are shown in Table 2.

  The anisotropic conductive member of the present invention can be used as a connector for inspection when performing functional inspection of electronic components such as semiconductor elements. As shown in the examples, the probe is a conventionally known semiconductor inspection apparatus. It can also be used in combination with a card.

The anisotropic conductive member of the present invention can also be used as an electrical contact (electronic connection member) between a mother board such as a CPU and an interposer, and is used as an electrical contact between the interposer and the Si wafer. You can also.
In such a case, it can be used as an inspection probe by combining the film of the present invention on a substrate on which signal extraction pads are wired instead of a probe.
In addition, by integrating the anisotropic conductive member of the present invention on the signal extraction surface of the Si wafer, the wiring structure is not damaged, and a very precise alignment is required in the manufacturing method. It is possible to take out an electric signal.

The anisotropic conductive member of the present invention has a predetermined diameter and a predetermined width, such as a display label for displaying a price display, a date display, etc., on a product, particularly when used as an electronic connection member. The anisotropic conductive member 73 having a predetermined size can be supplied on the outer surface of the tape (mounting paper) 72 wound around the winding core 71 (see FIG. 7).
Here, for example, the dimension of the anisotropic conductive member is approximately the same as the dimension of the semiconductor chip using the anisotropic conductive member, and the width of the tape can be appropriately determined according to the width of the anisotropic conductive member.
In addition, when it is difficult to cut or bend later depending on the material of the substrate of the anisotropic conductive member, the diameter and width of the winding core should be determined appropriately according to the dimensions of the anisotropic conductive member. Is desirable. Specifically, it is desirable to increase the diameter of the winding core as the size of the anisotropic conductive member in the tape length direction increases.
Moreover, although the anisotropic conductive member is affixed on the tape, it is preferable that the material of the tape is such that no adhesive remains on the surface of the anisotropic conductive member when the anisotropic conductive member is peeled off. .
In this supply form, the user can peel off and use the anisotropic conductive film affixed to the tape one by one.

In addition, the anisotropic conductive member of the present invention is supplied in a state where anisotropic conductive members 82 having predetermined dimensions are placed side by side in a drawer-type storage box 81, particularly when used as an electronic connection member. (See FIG. 8).
Here, the dimension of a storage box can be suitably changed according to the dimension of an anisotropic conductive member.
In addition, since the adjacent anisotropic conductive members are in contact with each other inside the storage box, adjacent anisotropies such as inserting a cushioning material between them or packing individual anisotropic conductive films It is desirable to store the conductive films so that they do not contact each other.
In this supply form, the user can take out and use the anisotropic conductive films stored in the storage box one by one.

In addition, the anisotropic conductive member of the present invention is used on an entire surface of one surface of a substantially circular resin plate 91 having a predetermined diameter, such as a semiconductor wafer, particularly when used as an electronic connection member. Can be supplied (see FIG. 9).
Here, the diameter of the resin plate can be, for example, 5 inches or 8 inches, which is substantially the same as the diameter of a semiconductor wafer using this anisotropic conductive film.
In addition, the anisotropic conductive member can be used by cutting to approximately the same dimension as the semiconductor chip using the same as, for example, the wafer level chip size package of the semiconductor chip. It is desirable to make a cut 93 in advance with the resin plate.
In this supply form, the user cuts the anisotropic conductive film attached to the entire surface of one side of the resin plate together with the resin plate along the cut line and then divides it individually, and then removes the resin plate. An anisotropic conductive film can be used.

  Further, when the anisotropic conductive member of the present invention is used as a connection member between individual semiconductor chips and an interposer, the semiconductor wafer and the interposer can be supplied in a state where they are connected in advance with an anisotropic conductive film.

  Furthermore, the anisotropic conductive member of the present invention can be expected to be used as an optical transmission material.

FIG. 1 is a simplified diagram showing an example of a preferred embodiment of the anisotropic conductive member of the present invention. FIG. 2 is a schematic view of a block copolymer thin film and an insulating base material separated by microphase. FIG. 3 is a schematic end view for explaining an example of a metal filling step and the like in the production method of the present invention. FIG. 4 is a schematic cross-sectional view illustrating the procedure of the method for manufacturing the anisotropic conductive member of Comparative Example 1. FIG. 5 is an explanatory diagram for calculating the density of the conductive path of the conductive member (film). FIG. 6 is a schematic view of an apparatus for measuring the insulation (electric resistance) in the surface direction of the anisotropic conductive member (film) obtained in Example 1 and Comparative Example 1. FIG. 7 is a schematic diagram for explaining an example of a supply form of the anisotropic conductive member of the present invention. FIG. 8 is a schematic diagram for explaining an example of the supply form of the anisotropic conductive member of the present invention. FIG. 9 is a schematic diagram for explaining an example of a supply form of the anisotropic conductive member of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anisotropic conductive member 2 Insulating base material 3 Conducting path 4a, 4b Protrusion part 5 In-base material conducting part 6 Insulating base material thickness 7 Width between conducting paths 8 Diameter of conducting path 9 Distance between centers of conducting paths (pitch)
20 Insulating Base Material 21 Anisotropic Conductive Member 41 Copper Substrate 42 Resist Layer 43 Mask 44 X-ray M Master 45 Microstructure Resist Film (Residual Resist Film)
46 Nickel conductive fine wire group 47 Plating bath V Substrate 48 Sheet-like base material 49 Anisotropic conductive film 51 Unit grid of through hole 52 Conductive electrode part 61 Device 62 Electrode 71 Winding core 72 Tape (mounting paper)
73, 82, 92 Anisotropic conductive member 81 Storage box 91 Resin plate 93 Cut 101 Block copolymer thin film (insulating member)
102 Hydrophobic polymer chain B
103 hydrophilic polymer chain A
104 Insulating substrate 105 Through hole

Claims (4)

In the insulating base material, a plurality of conductive paths made of a conductive member penetrate the insulating base material in the thickness direction in a state of being insulated from each other, and one end of each of the conductive paths is the insulating base material An anisotropic conductive member that is exposed or protrudes on one side of the conductive path and that the other end of each conduction path is exposed or protruded on the other side of the insulating base material,
An anisotropic conductive member, wherein the density of the conduction paths is 2 million pieces / mm ² or more.   The anisotropic conductive member according to claim 1, wherein a length (length / thickness) of a center line of the conduction path with respect to a thickness of the insulating base material is 1.0 to 1.2. A method for producing an anisotropic conductive member for producing the anisotropic conductive member according to claim 1, wherein at least:
A penetration treatment step of forming a through hole in the insulating member; and
An anisotropic conductive member comprising, after the penetrating treatment step, a metal filling step of filling the inside of the penetrated hole in the obtained insulating member with a conductive member to obtain the anisotropic conductive member. Manufacturing method.   The penetration process step is a step of performing a process of removing a portion related to the forested phase separation structure on an insulating member made of a polymer material and having a phase separation structure forested in the depth direction. Item 4. A method for producing an anisotropic conductive member according to Item 3.

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