JP2019149448A - Anisotropic conductive member, manufacturing method of anisotropic conductive member, joint body, and electronic device - Google Patents

Abstract

To provide an anisotropic conductive member, a manufacturing method of the anisotropic conductive member, a joint body, and an electronic device, suppressing conduction between adjacent conductive bodies, and suppresses influence to the electric conduction performance.SOLUTION: An anisotropic conductive member includes: an insulation base material; and a plurality of conductive bodies penetrated and provided in a thickness direction of the insulation base material. Each conductive material comprises a projection part projected from at least one surface of the insulation base material. The plurality of conductive bodies has the same length with the projection part. The projection part comprises: a base part on the insulation base material side; and a tip part provided to an end surface opposite to the insulation base material of the base part, and the tip part is a metal-containing portion having a component difference from the base part of the tip part.SELECTED DRAWING: Figure 1

Description

  The present invention includes an anisotropic conductive member having a conductor penetrating in the thickness direction of an insulating base material, the conductor having a protruding portion protruding from at least one surface of the insulating base material, and anisotropic conductive property BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a member, and a joined body and an electronic device having anisotropic conductive members. The present invention relates to a member, a method for manufacturing an anisotropic conductive member, a joined body, and an electronic device.

A metal-filled microstructure including a conductor composed of a metal filled in a plurality of through-holes penetrating in the thickness direction of an insulating substrate is one of the fields attracting attention in nanotechnology in recent years. The metal-filled microstructure is expected to be used for, for example, battery electrodes, gas permeable membranes, sensors, and anisotropic conductive members.
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 and a connector for inspection when performing a function inspection.
In particular, downsizing is remarkable in electronic components such as semiconductor elements. In the conventional method of directly connecting a wiring board such as wire bonding, flip chip bonding, and thermo compression bonding, etc., it is not possible to sufficiently guarantee the stability of electrical connection of electronic components. Anisotropic conductive members are attracting attention.

Patent Document 1 describes a structure that can be used as an anisotropic conductive member and has both bonding suitability and conductivity. The structure of Patent Document 1 is a structure in which a conductor penetrates an insulating substrate, the conductor has a circle-equivalent diameter of 10 to 500 nm, and a height from the surface of the insulating substrate is 50 nm or more. The surface of the protrusion is covered with metal, and the height H (nm) of the protrusion including the covering layer covering the protrusion and the thickness T (nm) of the covering layer are The relationship of T / H ≦ 0.8 is satisfied.
Non-Patent Document 1 discloses that anodized aluminum (AAO) is filled with metal by plating, and further dissimilar metals are laminated, and then anodized aluminum (AAO) is dissolved and removed to form fine lot-shaped metal particles. It describes how to earn.

JP 2009-289730 A

Zhen Wang Mathias Brust, “Fabrication of nanostructure via self-assembly of nanowires within the AAO template”, Nanoscale Res Lett (2007) 2: 34-39

Currently, as described above, downsizing is remarkable in electronic components such as semiconductor elements, the size of electrodes and terminals is smaller, the number of electrodes and terminals is increased, and the distance between terminals is also narrower. It is coming. An anisotropic conductive member is required to be able to cope with electrical connection of various types of electronic components.
However, in patent document 1, when the arrangement | positioning space | interval of a conductor is made narrower, adjacent conductors may conduct | electrically_connect by a coating layer. For this reason, there is a possibility that it is not possible to cope with an electronic component having a narrower distance between terminals.
In Non-Patent Document 1, the metal is filled and deposited by AC electrolysis, and the length variation cannot be avoided, and the length of the conductor varies. For this reason, when using for electrical connection of an electronic component, when an electric conductor falls down by external force, adjacent electric conductors may contact and be conducted.

  An object of the present invention is to provide an anisotropic conductive member and an anisotropic conductive member that suppress electrical conduction between adjacent electrical conductors and suppresses the influence on electrical conductivity even when the arrangement interval of the electrical conductors is narrower. A manufacturing method, a joined body, and an electronic device are provided.

In order to achieve the above-described object, the present invention has an insulating base material and a plurality of conductors provided penetrating in the thickness direction of the insulating base material. A plurality of conductors each having the same length of the protruding portion, and the protruding portion includes a base on the side of the insulating base and an insulating base on the base The tip part provided only in the end surface on the opposite side is provided with an anisotropic conductive member, which is a metal-containing part having a composition different from that of the base part.
It is preferable that the metal which comprises a front-end | tip part has a smaller ionization tendency than the metal which comprises a base.
Each conductor preferably has a protruding portion protruding from the front surface and the back surface of the insulating substrate.
The equivalent circle diameter of the base portion and the equivalent circle diameter of the tip portion are preferably the same.
The insulating substrate is preferably composed of a metal anodized film, and the insulating substrate is desirably composed of an aluminum anodized film or a titanium anodized film.

Further, the present invention provides a first conductor filling step of filling a through hole with a first conductor made of metal in an insulating base material having a plurality of through holes extending in the thickness direction, A surface smoothing step of smoothing at least one surface of the insulating base material filled with the first conductor; and removing a part of the first conductor on the smoothed surface side; A first conductor removing step of lowering the surface below the smoothed surface, and a second conductor laminating step of laminating a second conductor containing a metal having a composition different from that of the first conductor on the surface of the first conductor. And an insulating base material removing step of removing a part of the smoothed surface side of the insulating base material and causing the first conductor and the second conductor to protrude from the insulating base material in this order. A method for producing a directionally conductive member is provided.
The first conductor removing step is preferably a step of dissolving the first conductor, and the insulating base material removing step is preferably a step of dissolving the insulating base material.
It is preferable that the insulating base material is in contact with the liquid from the end of the first conductor removing step to the start of the second conductor laminating step.
In the surface smoothing step, it is preferable to smooth both surfaces of the insulating base material in which the first conductor is filled in the through hole.
It is preferable that the metal which comprises a 2nd conductor has a smaller ionization tendency than the metal which comprises a 1st conductor.
The insulating substrate is preferably composed of a metal anodized film, and the insulating substrate is desirably composed of an aluminum anodized film or a titanium anodized film.

The present invention provides a joined body having the anisotropic conductive member of the present invention and a member having a conductive region and joined to the anisotropic conductive member.
Moreover, the electronic device containing the conjugate | zygote of this invention is provided.

ADVANTAGE OF THE INVENTION According to this invention, the anisotropic conductive member which suppressed conduction | electrical_connection between adjacent conductors and suppressed the influence on electrical conductivity can be provided.
Moreover, according to this invention, the manufacturing method of the above-mentioned anisotropic conductive member can be provided.
Furthermore, according to the present invention, a joined body and an electronic device having an anisotropic conductive member can be provided.

It is a typical section showing an example of an anisotropic conductive member of an embodiment of the present invention. It is a top view which shows an example of the anisotropically conductive member of embodiment of this invention. It is a typical sectional view expanding and showing an anisotropic conductive member of an embodiment of the present invention. It is a schematic diagram which shows 1 process of the 1st example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 1st example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 1st example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 1st example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 1st example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 2nd example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 2nd example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 2nd example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 2nd example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of the 2nd example of the manufacturing method of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of an example of the formation method of the through-hole of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows 1 process of an example of the formation method of the through-hole of the anisotropically conductive member of embodiment of this invention. It is a schematic diagram which shows the 1st example of the electronic device of embodiment of this invention. It is typical sectional drawing which shows an example of a structure of the terminal of the semiconductor element of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 2nd example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 3rd example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 4th example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 5th example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 6th example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 7th example of the electronic device of embodiment of this invention. It is a schematic diagram which shows the 8th example of the electronic device of embodiment of this invention.

Hereinafter, based on preferred embodiments shown in the accompanying drawings, an anisotropic conductive member, a method for manufacturing an anisotropic conductive member, a joined body, and an electronic device of the present invention will be described in detail.
In addition, the figure demonstrated below is an illustration for demonstrating this invention, and this invention is not limited to the figure shown below.
In the following, “to” indicating a numerical range includes numerical values written on both sides. For example, when ε is a numerical value α to a numerical value β, the range of ε is a range including the numerical value α and the numerical value β, and α ≦ ε ≦ β in mathematical symbols.
Further, various values represented by specific numerical values include an error range generally allowed in the corresponding technical field.

(Anisotropic conductive member)
FIG. 1 is a schematic cross-sectional view showing an example of the anisotropic conductive member of the embodiment of the present invention, FIG. 2 is a plan view showing an example of the anisotropic conductive member of the embodiment of the present invention, and FIG. It is a typical sectional view expanding and showing an anisotropic conductive member of an embodiment of the present invention. In FIG. 2, the resin layer 19 is not shown.

An anisotropic conductive member 10 shown in FIG. 1 includes an insulating base 12, a plurality of through holes 14 provided in the insulating base 12 and penetrating in the thickness direction Dt of the insulating base 12, and a plurality of throughs. And a conductor 16 provided in the hole 14.
Each of the plurality of conductors 16 is a columnar member provided so as to penetrate in the thickness direction of the insulating base 12. The plurality of conductors 16 exist in a state where they are electrically insulated from each other by the insulating substrate 12.
Each of the plurality of conductors 16 is made of metal, has conductivity, functions as an electrical conduction path, and transmits an electrical signal. The conductor 16 also functions as a conductive path in the bonded body and electronic device described later.
Here, “the state of being electrically insulated from each other” means that the respective conductors 16 existing inside the insulating base material have sufficient conductivity between the respective conductors inside the insulating base material 12. It means that it is in a low state.
The anisotropic conductive member 10 has a sufficiently low conductivity in the direction x orthogonal to the thickness direction Dt of the insulating substrate 12 and has a conductivity in the thickness direction Dt.

The conductor 16 includes a protrusion 16b that protrudes from the surface 12a in the thickness direction Dt of the insulating substrate 12, and a protrusion 16c that protrudes from the back surface 12b. A resin layer 19 for embedding 16c is provided. Further, a portion of the conductor 16 that is in the insulating base 12, that is, a portion corresponding to the portion of the through hole 14 is referred to as a through portion 16 a. The penetration part 16a and the base part 20 of the protrusion parts 16b and 16c are integral structures.
As shown in FIG. 2, the conductor 16 is disposed at a center-to-center distance p with respect to the insulating substrate 12. The center-to-center distance p and the density of the conductor 16 will be described in detail later.

As shown in FIG. 1, the protruding portion 16 b and the protruding portion 16 c are both a base portion 20 on the insulating base material 12 side and a tip portion 21 provided only on the end surface 20 d of the base portion 20 on the opposite side of the insulating base material 12. With. The tip portion 21 is a metal-containing portion having a composition different from that of the base portion 20, but the penetrating portion 16a and the base portion 20 of the projecting portions 16b and 16c are integrally configured and have the same composition. The conductor 16 may be composed entirely of metal, but may be configured such that the penetrating portion 16a excluding the distal end portion 21 and the base portion 20 of the projecting portions 16b and 16c are composed of metal.
The provision of the tip portion 21 only on the end surface 20d means that neither of the protruding portions 16b and 16c of the conductor 16 has a layer or the like on the side surface 20c of the base portion 20, and the side surface 20c of the base portion 20 has the tip portion 21 is in a state where it is not covered by 21.
Due to the configuration of the conductor 16 described above, in the anisotropic conductive member 10, even if the arrangement interval of the adjacent conductors 16, that is, the width w between the adjacent conductors 16 is narrowed, a part of the conductor 16 remains. Without contact with the adjacent conductors 16, the conduction between the adjacent conductors 16 can be suppressed, that is, the leakage between the adjacent conductors 16 can be suppressed, and the influence on electrical conductivity can be suppressed. Can do. In addition, the spacing between the conductors 16 can be reduced.

  In addition, since the front-end | tip part 21 suppresses the oxidation of the base 20, it is preferable that the front-end | tip part 21 is continuously provided in the end surface 20d of the base 20. FIG. The fact that the tip 21 is continuously provided on the end surface 20d of the base 20 means that a layer formed in the course of a manufacturing process such as an oxide film between the end surface 20d of the base 20 and the tip 21 and intentionally This means that there is no layer formed.

Further, it is preferable that the equivalent circle diameter R of the base portion 20 and the equivalent circle diameter Rs of the distal end portion 21 are the same. In this case, even if the arrangement interval of the adjacent conductors 16, that is, the width w between the adjacent conductors 16 is further narrowed, conduction between the adjacent conductors 16 is suppressed, that is, between the adjacent conductors 16. Leakage can be suppressed and influence on electrical conductivity can be suppressed. In addition, the spacing between the conductors 16 can be further reduced.
Note that the equivalent circle diameter R of the base portion 20 and the equivalent circle diameter Rs of the distal end portion 21 are the same, assuming that the smaller equivalent circle diameter is 100, the larger equivalent circle diameter is within 120. That means. For example, when the equivalent circle diameter R of the base portion 20 is 100 nm, it is the same if the equivalent circle diameter Rs of the tip portion 21 is 120 nm or less. When the equivalent circle diameter Rs of the tip portion 21 is 100 nm, the same is true if the equivalent circle diameter R of the base portion 20 is 120 nm or less.
In FIG. 1, the base portion 20 has a columnar shape and the tip portion 21 also has a column shape, but the tip portion 21 is not limited to a column shape. For example, the tip portion 21 may be hemispherical or conical.

The base 20 is made of metal. A metal constituting the base 20 is referred to as a first metal. That the base 20 is comprised with the 1st metal means containing 95 mass% or more of 1st metals.
The tip portion 21 is a metal-containing portion having a composition different from that of the base portion 20 as described above, and is made of, for example, a metal. The metal constituting the tip portion 21 is referred to as a second metal. That the front-end | tip part 21 is comprised with 2nd metal means containing 95 mass% or more of 2nd metals. The tip portion 21 may be a metal-containing portion having a composition different from that of the base portion 20, and is not limited to the tip portion 21 being made of metal. For example, you may comprise with resin containing a nanosize metal particle.
For example, the base 20 and the tip 21 are made of metals having different compositions. In this case, a metal having a different composition means that when two compositions are compared, the types of constituent elements are different in the case of a single metal. In the case of an alloy, when the main components having a content of 50% by mass or more are compared, the types of the main component elements are different.

Note that whether the tip 21 is a metal-containing part having a composition different from that of the base 20 or whether the base 20 and the tip 21 are made of different metals is determined by the insulating base material of the anisotropic conductive member 10. 12 is selectively dissolved and the conductor 16 is taken out. It can be specified by separating the base 20 and the tip 21 by selectively dissolving the base 20 or the tip 21 using an etching solution that dissolves a certain metal and does not dissolve another metal.
An etching solution in which the first metal constituting the base portion 20 is dissolved and the second metal constituting the tip portion 21 is not dissolved, or the first metal constituting the base portion 20 is not dissolved and the first metal constituting the tip portion 21 is dissolved. The base 20 or the tip 21 is selectively dissolved using an etching solution in which two metals are dissolved, and the base 20 and the tip 21 are separated.

In the base 20 and the tip portion 21, the second metal constituting the tip portion 21 may have a smaller ionization tendency than the first metal constituting the base portion 20, and conversely, the second metal has a greater ionization tendency than the first metal. May be.
When the 2nd metal which comprises the front-end | tip part 21 has a smaller ionization tendency than the 1st metal which comprises the base 20, the oxidation of the front-end | tip part 21 is suppressed and the oxidation of the base 20 is also suppressed.
On the other hand, when the second metal constituting the tip portion 21 has a higher ionization tendency than the first metal constituting the base portion 20, the tip portion 21 is preferentially oxidized and the oxidation of the base portion 20 is suppressed.

The plurality of conductors 16 have the same length of the protruding portion 16b, that is, the height H of the protruding portion 16b, the tips of all the tip portions 21 are on the plane PL, and the tip portions 21 are substantially in the same plane. It is provided so that it may be located on the top. Further, the length of the protruding portion 16c, that is, the height H of the protruding portion 16b is the same, the tips of all the tip portions 21 are on the plane PL, and the tip portions 21 are positioned on substantially the same plane. Is provided.
The above-described protrusions 16b have the same length, that is, the tips are located on substantially the same plane, which means that the tips of the tips 21 of all the protrusions 16b are within a range of ± 100 nm. That is, the fluctuation of the tip of the tip portion 21 of the protrusion 16b is within a range of ± 100 nm.
In addition, the above-described protrusions 16c have the same length, that is, the tips are located on substantially the same plane, which means that the height difference of the tips of all the protrusions 16c is within a range of ± 50 nm. That is, the variation of the tip of the tip portion 21 of the protruding portion 16c is within a range of ± 50 nm.
Also, as shown in FIG. 3, the height H of the protrusion 16b is assumed, the height of the tip 21 of the protrusion 16b is Hs, and the equivalent circle diameter of the protrusion 16b is R. In this case, it is preferable that Hs <2R. When Hs <2R is satisfied, electrical conduction between adjacent conductors 16, that is, leakage is reliably suppressed. The height H of the protrusion 16b is preferably 50 nm or more.

  In the configuration of the anisotropic conductive member 10 shown in FIG. 1, there is a configuration in which there are a protruding portion 16 b protruding from the front surface 12 a of the insulating substrate 12 and a protruding portion 16 c protruding from the back surface 12 b. It is not something. The anisotropic conductive member 10 only needs to have a protruding portion on at least one surface of the insulating base material 12, that is, the anisotropic conductive member 10 may have any one of the protruding portion 16b and the protruding portion 16c.

(First example of manufacturing method of anisotropic conductive member)
Next, a first example of the method for manufacturing the anisotropic conductive member 10 will be described. 4 to 8 are schematic views showing a first example of the method for manufacturing an anisotropic conductive member according to the embodiment of the present invention in the order of steps.
4-8, the same code | symbol is attached | subjected to the same structure as the anisotropic conductive member 10 shown in FIG. 1 and FIG. 2, and the detailed description is abbreviate | omitted.

First, as shown in FIG. 4, an insulating substrate 12 having a plurality of through holes 14 extending in the thickness direction Dt is prepared.
Next, as shown in FIG. 5, the first conductor 22 made of metal is filled into the through hole 14 of the insulating substrate 12 having a plurality of through holes 14 extending in the thickness direction Dt. The step of filling the above-described through hole 14 with the first conductor 22 is the first conductor filling step. The first conductor 22 constitutes the penetrating portion 16a of the conductor 16 and the base portion 20 of the protruding portions 16b and 16c. By the first conductor 22, the penetrating portion 16a of the conductor 16 and the base portion 20 of the protruding portions 16b and 16c are integrally formed. The metal which comprises the 1st conductor 22 is the above-mentioned 1st metal, for example.
Next, at least one surface of the insulating base material 12 in which the through-hole 14 is filled with the first conductor 22 is smoothed. For example, the surface 12a of the insulating substrate 12 is smoothed. The above-described smoothing process is a surface smoothing process. By the surface smoothing step, the first conductor 22 is exposed on the surface 12a of the insulating base 12.

Next, as shown in FIG. 6, a part of the first conductor 22 on the smoothed surface side, that is, the surface 12 a side of the insulating base 12 is removed, and the surface 22 a of the first conductor 22 is removed. The surface is smoothed, that is, lower than the surface 12 a of the insulating substrate 12. The step of removing a part of the first conductor 22 and making the surface 22a of the first conductor 22 lower than the smoothed surface is the first conductor removing step.
The first conductor removing step is, for example, a step of dissolving the first conductor 22. The insulating base 12 and the first conductor 22 have different compositions. For example, by selecting an etching solution, the insulating base 12 is not removed, and only the first conductor 22 can be selectively removed. it can.
As long as only the first conductor 22 can be selectively removed, the first conductor removing step is not limited to dissolution using an etching solution or the like, and may be, for example, a dry etching process.

Next, as shown in FIG. 7, for example, a second conductor 23 made of a metal having a composition different from that of the first conductor 22 is laminated on the surface 22 a of the first conductor 22. The second conductor 23 constitutes the distal end portion 21 of the projecting portions 16 b and 16 c of the conductor 16. The metal which comprises the 2nd conductor 23 is a 2nd metal, for example, and the composition of the above-mentioned 1st metal and a 2nd metal differs. In addition, the 2nd conductor 23 will not be specifically limited to the above-mentioned metal, if the metal which has a composition different from the 1st conductor 22 used as the base 20 (refer FIG. 1) is included.
The step of laminating the second conductor 23 having a composition different from that of the first conductor 22 on the surface 22a of the first conductor 22 is the second conductor laminating step. In the through hole 14, the second conductor 23 is laminated in succession to the first conductor 22 by the second conductor laminating step. In this case, the through hole 14 functions as a mold, and the inner surface of the through hole 14 becomes a side surface 20c (see FIG. 3) of the base portion 20 of the protruding portion 16b and a side surface 21c (see FIG. 3) of the distal end portion 21. For this reason, the first conductor 22 and the second conductor 23 have substantially the same equivalent circle diameter.

In the second conductor laminating step, the second conductor 23 is preferably laminated so as not to overflow from the through hole 14. When the 2nd conductor 23 overflows from the through-hole 14, the grinding | polishing etc. of the 2nd conductor 23 are needed and a process becomes complicated. For example, when the plating method is used, the amount of lamination of the second conductor 23 can be adjusted according to plating processing conditions such as plating processing time.
The first conductor 22 may overflow from the through hole 14 because of the surface smoothing step, but it is preferable that the first conductor 22 does not overflow from the through hole 14 like the second conductor 23. In this case, as with the second conductor 23, the amount of the first conductor 22 stacked can be adjusted according to the plating process conditions such as the plating process time when the plating method is used.

Next, as shown in FIG. 8, the smoothed surface side of the insulating base material 12, for example, a part on the surface 12 a side of the insulating base material 12 is removed, and the first conductor 22 and the second conductor are removed. 23 protrudes from the insulating substrate 12. Thereby, the protrusion part 16b which protrudes from the surface 12a of the insulating base material 12 is formed. The first conductor 22 serves as the through portion 16a of the conductor 16 and the base portion 20 of the projecting portions 16b and 16c, and the second conductor 23 serves as the distal end portion 21 of the projecting portion 16b.
The step of removing a part of the smoothed surface side of the insulating base 12 and causing the first conductor 22 and the second conductor 23 to protrude from the insulating base 12 is an insulating base removing step. .
The removal of a part of the smoothed surface side of the insulating base 12 described above is, for example, a step of dissolving the insulating base 12. In this case, for example, by selecting an etching solution, the first conductor 22 and the second conductor 23 are not etched, and the insulating base 12 is selectively etched to remove the insulating base 12. Can do.
In this way, the anisotropic conductive member 10 having the protruding portion 16b protruding from the surface 12a of the insulating base 12 can be obtained.
In addition, for example, a resin layer 19 in which the protruding portion 16b of the conductor 16 is embedded may be formed in the state shown in FIG.

Between the end of the first conductor removing step and the second conductor laminating step, the drying step is not included between the end of the first conductor removing step and the start of the second conductor laminating step. The insulating substrate is preferably kept in contact with the liquid. Thereby, the oxidation of the surface 22a of the first conductor 22 can be suppressed. In this case, the liquid is a plating solution for the plating treatment, and although not described in detail, pure water or the like used for the cleaning process between the processes.
In addition to contacting the liquid, the oxidation may be suppressed by reducing the pressure between the steps or by setting the atmosphere to an inert gas atmosphere. When both the first conductor 22 and the second conductor 23 are formed by a plating method, the production line can be simplified if they are in contact with a liquid.
In addition, when the 1st conductor 22 and the 2nd conductor 23 are not a series of continuous processes, between each process is good also as a pressure-reduced atmosphere or an inert gas atmosphere as mentioned above.

(Second example of manufacturing method of anisotropic conductive member)
Next, a second example of the method for manufacturing the anisotropic conductive member 10 will be described. 9 to 13 are schematic views showing a second example of the method for manufacturing the anisotropic conductive member according to the embodiment of the present invention in the order of steps.
9-13, the same code | symbol is attached | subjected to the same structure as the 1st example of the manufacturing method of the anisotropically conductive member shown in FIGS. 4-8, and the detailed description is abbreviate | omitted.

A second example of the method for manufacturing the anisotropic conductive member 10 is a method for manufacturing the anisotropic conductive member 10 having the protrusions 16 b and 16 c on both surfaces of the insulating base 12.
Since the process of forming the protrusion 16b on the surface 12a of the insulating substrate 12 is the same as the first example of the method for manufacturing the anisotropic conductive member described above, detailed description thereof is omitted.
In the second example of the manufacturing method of the anisotropic conductive member 10, first, the surface 12a of the insulating base 12 is shown in FIG. As shown, a resin layer 19 is formed to embed the protruding portion 16b of the conductor 16. Next, the double-sided adhesive 24 is affixed to the resin layer 19. Then, the support member 25 is attached to the double-sided pressure-sensitive adhesive 24.
Next, a surface smoothing process is implemented with respect to the back surface 12b of the insulating base material 12, and the 1st conductor 22 is exposed to the back surface 12b of the insulating base material 12. FIG.

As the support member 25, for example, a silicon substrate is used. As the support member 25, for example, a ceramic substrate such as SiC, SiN, GaN, and alumina (Al ₂ O ₃ ), a glass substrate, a fiber reinforced plastic substrate, and a metal substrate can be used in addition to the silicon substrate. The fiber reinforced plastic substrate includes an FR-4 (Flame Retardant Type 4) substrate which is a printed wiring board.
The structure of the double-sided pressure-sensitive adhesive 24 is not particularly limited as long as the resin layer 19 and the support member 25 can be bonded. For example, a double-sided type Riva Alpha (registered trademark) manufactured by Nitto Denko Corporation Can be used.

Next, a first conductor removing step is performed on the back surface 12b side of the insulating base material 12, and the first conductor 22 is selectively removed. As shown in FIG. 10, the surface 22b of the first conductor 22 is removed. Is made lower than the smoothed surface, that is, the back surface 12b of the insulating substrate 12.
Next, the second conductor laminating step is performed on the surface 22b of the first conductor 22, and the second conductor 23 is laminated on the surface 22b of the first conductor 22 as shown in FIG.
The second conductor 23 is laminated in succession to the first conductor 22 in the through hole 14 by the second conductor lamination step. Also in this case, the through hole 14 functions as a mold, and the inner surface of the through hole 14 becomes a side surface 20c (see FIG. 3) of the base portion 20 of the protruding portion 16c and a side surface 21c of the tip portion 21 (see FIG. 3). For this reason, the first conductor 22 and the second conductor 23 have substantially the same equivalent circle diameter. As described above, the second conductor 23 is preferably laminated so as not to overflow from the through hole 14.

Next, the insulating base material removing step is performed on the back surface 12b of the insulating base material 12, and a part of the insulating base material 12 on the back surface 12b side is removed as shown in FIG. The body 22 and the second conductor 23 are projected from the insulating substrate 12. Thereby, the protrusion part 16c which protrudes from the back surface 12b of the insulating base material 12 is formed, and the anisotropic conductive member 10 which has the protrusion parts 16b and 16c on both surfaces of the insulating base material 12 can be obtained.
The first conductor 22 serves as the base 20 of the projecting portion 16c, and the second conductor 23 serves as the distal end portion 21 of the projecting portion 16c.

Next, as illustrated in FIG. 13, a resin layer 19 in which the protruding portion 16 c is embedded in the back surface 12 b of the insulating base 12 may be formed.
In this case, a protective layer 29 may be provided on the resin layer 19 on the back surface 12b side of the insulating substrate 12. The protective layer 29 protects the anisotropic conductive member 10 from the back surface 12b side of the insulating substrate 12.
Then, the double-sided pressure-sensitive adhesive 24 and the support member 25 on the surface 12a side of the insulating base 12 are removed. Thereby, the anisotropic conductive member 10 of the form shown in FIG. 13 can be obtained.
The anisotropic conductive member 10 shown in FIG. 13 can be stored, for example, in a state of being wound in a roll shape around a winding core. The resin layer 19 can be peeled off when the anisotropic conductive member 10 is used.

Since the protective layer 29 is used to protect the surface of the structure from scratches, an easily peelable tape is preferable. As the protective layer 29, for example, a film with an adhesive layer may be used.
As a film with an adhesive layer, for example, Sanitect (SUNYECT) [registered trademark] (manufactured by Sanei Kaken Co., Ltd.) in which an adhesive layer is formed on the surface of a polyethylene resin film, an adhesive layer is formed on the surface of a polyethylene terephthalate resin film. E-MASK [registered trademark] (manufactured by Nitto Denko Corporation), and MASTAK [registered trademark] (manufactured by Fujimori Kogyo Co., Ltd.) in which an adhesive layer is formed on the polyethylene terephthalate resin film surface. Commercially available products can be used.
Moreover, the method of affixing the film with an adhesion layer is not specifically limited, It can affix using a conventionally well-known surface protection tape sticking apparatus and a laminator.

Next, a method for manufacturing the insulating substrate 12 having the through holes 14 shown in FIG. 4 will be described.
FIG. 14 and FIG. 15 are schematic views showing an example of a method for forming a through hole of an anisotropic conductive member according to an embodiment of the present invention in the order of steps, and a method for manufacturing an insulating substrate 12 having a through hole 14 It is not limited to.
First, as shown in FIG. 14, a substrate 26 to be the insulating base 12 (see FIG. 1) is prepared.
The size and thickness of the substrate 26 are appropriately determined according to the thickness of the insulating base 12 of the anisotropically conductive member 10 (see FIG. 1) finally obtained, the processing apparatus, and the like. The substrate 26 may be a rectangular or disk-shaped plate material or a belt-shaped plate material.
The insulating base 12 is composed of, for example, an anodized film. In this case, the substrate 26 is composed of a material that can be anodized. The anodized film is composed of, for example, an anodized film formed by anodizing a metal. The metal that becomes the anodized film is, for example, aluminum or titanium.

Next, the surface 26a on one side of the substrate 26 is anodized. As a result, the surface 26a on one side of the substrate 26 is anodized, and as shown in FIG. 15, the anodization having the barrier layer 27 present at the bottom of the plurality of through holes 14 extending in the thickness direction Dt of the substrate 26. A film 28 is formed. The above-described anodizing process is called an anodizing process.
In the anodic oxide film 28 having the plurality of through holes 14, the barrier layer 27 exists at the bottom of the through hole 14 as described above, but the barrier layer 27 is removed. The step of removing the barrier layer 27 is called a barrier layer removing step.
In the barrier layer removing step, by using an alkaline aqueous solution containing metal ions having a hydrogen overvoltage higher than that of aluminum, the barrier layer 27 of the anodized film 28 is removed, and at the same time, a metal (metal M) is formed on the bottom of the through hole 14. A metal layer (not shown) is formed. Thereby, the board | substrate 26 of the bottom of the through-hole 14 is coat | covered with a metal layer (not shown).
By removing the substrate 26, the insulating base material 12 in which the through holes 14 are formed can be obtained as shown in FIG.
Hereinafter, each step of the method for manufacturing the anisotropic conductive member 10 will be described more specifically.

[Insulating substrate forming process]
The insulating substrate 12 is made of, for example, an anodic oxide film. A conventionally well-known method can be used for the anodic oxidation process which forms the anodic oxide film for forming an insulating base material. For example, an anodized film is formed by subjecting an aluminum substrate to anodization.
As the anodizing treatment, it is preferable to use a self-regulating method or a constant voltage treatment from the viewpoint of increasing the regularity of the micropore arrangement and ensuring the anisotropic conductivity of the anisotropic conductive member.
Here, as for the self-ordering method and the constant voltage process of the anodizing process, the same processes as those described in paragraphs [0056] to [0108] and [FIG. 3] of Japanese Patent Application Laid-Open No. 2008-270158 are performed. Can be applied.

<Anodizing treatment>
The average flow rate of the electrolytic solution in the anodizing treatment for the aluminum substrate is preferably 0.5 to 20.0 m / min, more preferably 1.0 to 15.0 m / min, and 2.0 to 10 More preferably, it is 0.0 m / min.
Moreover, the method of flowing the electrolytic solution under the above-mentioned conditions is not particularly limited, but for example, a method using a general stirring device such as a stirrer is used. In particular, it is preferable to use a stirrer that can control the stirring speed by digital display because the average flow velocity can be controlled. Examples of such a stirring apparatus include “Magnetic Stirrer HS-50D (manufactured by AS ONE)” and the like.

For the anodizing treatment, for example, a method in which an aluminum substrate is used as an anode in a solution having an acid concentration of 1 to 10% by mass can be used.
The solution used for the anodizing treatment is preferably an acid solution, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid, glycolic acid, tartaric acid, malic acid, citric acid. Of these, sulfuric acid, phosphoric acid, and oxalic acid are particularly preferable. These acids can be used alone or in combination of two or more.

The conditions of the anodizing treatment cannot be determined unconditionally because they vary depending on the electrolytic solution used. In general, the electrolytic solution concentration is 0.1 to 20% by mass, the liquid temperature is −10 to 30 ° C., the current is It is preferable that the density is 0.01 to 20 A / dm ² , the voltage is 3 to 300 V, the electrolysis time is 0.5 to 30 hours, the electrolytic solution concentration is 0.5 to 15% by mass, the liquid temperature is −5 to 25 ° C., and the current density. It is more preferable that it is 0.05-15A / dm < ² >, voltage 5-250V, electrolysis time 1-25 hours, electrolyte concentration 1-10 mass%, liquid temperature 0-20 degreeC, current density 0.1-10A. / Dm ² , voltage of 10 to 200 V, and electrolysis time of 2 to 20 hours are more preferable.

<Barrier layer removal process>
The barrier layer removing step is a step of removing the barrier layer of the anodic oxide film using, for example, an alkaline aqueous solution containing ions of the metal M having a hydrogen overvoltage higher than that of aluminum.
The barrier layer is removed by the above-described barrier layer removing step, and a metal layer (not shown) made of metal M is formed at the bottom of the through hole.
Here, the hydrogen overvoltage is a voltage necessary for generating hydrogen. For example, the hydrogen overvoltage of aluminum (Al) is −1.66 V (Journal of the Chemical Society of Japan, 1982, (8). ), P1305-1313). In addition, the example of the metal M higher than the hydrogen overvoltage of aluminum and the value of the hydrogen overvoltage are shown below.
<Metal M and hydrogen (1N H ₂ SO ₄ ) overvoltage>
Platinum (Pt): 0.00V
・ Gold (Au): 0.02V
Silver (Ag): 0.08V
Nickel (Ni): 0.21V
Copper (Cu): 0.23V
-Tin (Sn): 0.53V
・ Zinc (Zn): 0.70V

In the present invention, the above-described barrier layer removal is performed because a substitution reaction is caused with the first metal constituting the first conductor 22 and the influence on the electrical characteristics of the metal filled in the through hole is reduced. The metal M used in the process is preferably a metal having a higher ionization tendency than the first metal constituting the first conductor 22.
Specifically, when the first metal constituting the first conductor 22 is copper (Cu), examples of the metal M used in the above-described barrier layer removing step include Zn, Fe, Ni, Sn, and the like. Among these, Zn and Ni are preferably used, and Zn is more preferably used.
Moreover, when the 1st metal which comprises the 1st conductor 22 is Ni, as the metal M used at the above-mentioned barrier layer removal process, Zn, Fe etc. are mentioned, for example, It is preferable to use Zn especially.

  The method for removing the barrier layer using an alkaline aqueous solution containing such metal M ions is not particularly limited, and examples thereof include a method similar to a conventionally known chemical etching treatment.

(Chemical etching process)
The removal of the barrier layer by the chemical etching process is performed, for example, by immersing the structure after the anodizing treatment step in an alkaline aqueous solution, filling the through hole with the alkaline aqueous solution, and then opening the through hole side of the through hole of the anodized film Only the barrier layer can be selectively dissolved by, for example, a method in which the surface is contacted with a pH (hydrogen ion index) buffer.

Here, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide as the alkaline aqueous solution containing ions of the metal M described above. Moreover, it is preferable that the density | concentration of aqueous alkali solution is 0.1-5 mass%. The temperature of the alkaline aqueous solution is preferably 10 to 60 ° C, more preferably 15 to 45 ° C, and further preferably 20 to 35 ° C.
Specifically, for example, 50 g / L, 40 ° C. phosphoric acid aqueous solution, 0.5 g / L, 30 ° C. sodium hydroxide aqueous solution, 0.5 g / L, 30 ° C. potassium hydroxide aqueous solution, etc. are preferably used. It is done.
In addition, as a pH buffer solution, the buffer solution corresponding to the above-mentioned alkaline aqueous solution can be used suitably.

  The immersion time in the alkaline aqueous solution is preferably 5 to 120 minutes, more preferably 8 to 120 minutes, still more preferably 8 to 90 minutes, and preferably 10 to 90 minutes. Particularly preferred. Especially, it is preferable that it is 10 to 60 minutes, and it is more preferable that it is 15 to 60 minutes.

<Another example of the barrier layer removing step>
In addition to the above, the barrier layer removing step may be a step in which the barrier layer of the anodized film is removed and a part of the aluminum substrate is exposed at the bottom of the through hole.
In this case, the method for removing the barrier layer is not particularly limited. For example, a method of dissolving the barrier layer electrochemically at a potential lower than the potential in the anodizing treatment in the anodizing treatment step (hereinafter referred to as “electrolytic removal treatment”). A method of removing the barrier layer by etching (hereinafter, also referred to as “etching removal treatment”); a combination of these methods (particularly, after the electrolytic removal treatment is performed, the remaining barrier layer is subjected to the etching removal treatment). And the like).

<Electrolytic removal treatment>
The electrolytic removal treatment is not particularly limited as long as it is an electrolytic treatment performed at a potential lower than the potential (electrolytic potential) in the anodizing treatment in the anodizing treatment step.
The electrolytic removal treatment can be performed continuously with the anodizing treatment, for example, by lowering the electrolytic potential at the end of the anodizing treatment step.

The electrolytic removal treatment can employ the same electrolytic solution and treatment conditions as those of the above-described conventionally known anodizing treatment except for the electrolytic potential.
In particular, when the electrolytic removal treatment and the anodic oxidation treatment are successively performed as described above, it is preferable to perform treatment using the same electrolytic solution.

(Electrolytic potential)
The electrolytic potential in the electrolytic removal treatment is preferably lowered continuously or stepwise (stepwise) to a potential lower than the electrolytic potential in the anodic oxidation treatment.
Here, the reduction width (step width) when the electrolytic potential is lowered stepwise is preferably 10 V or less, more preferably 5 V or less, and more preferably 2 V or less from the viewpoint of the withstand voltage of the barrier layer. More preferably it is.
In addition, the voltage drop rate when dropping the electrolytic potential continuously or stepwise is preferably 1 V / second or less, more preferably 0.5 V / second or less, and 0.2 V / second from the viewpoint of productivity. More preferred is less than a second.

<Etching removal treatment>
The etching removal process is not particularly limited, but may be a chemical etching process that dissolves using an acid aqueous solution or an alkali aqueous solution, or may be a dry etching process.

(Chemical etching process)
The removal of the barrier layer by the chemical etching treatment is performed, for example, by immersing the structure after the anodizing treatment step in an acid aqueous solution or an alkali aqueous solution, filling the inside of the micropore with an acid aqueous solution or an alkali aqueous solution, and then removing the anodized film. For example, the surface of the micropore opening side is brought into contact with a pH (hydrogen ion index) buffer solution, and only the barrier layer can be selectively dissolved.

Here, when an acid aqueous solution is used, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. The concentration of the acid aqueous solution is preferably 1% by mass to 10% by mass. The temperature of the acid aqueous solution is preferably 15 ° C to 80 ° C, more preferably 20 ° C to 60 ° C, and further preferably 30 ° C to 50 ° C.
On the other hand, when using an alkaline aqueous solution, it is preferable to use an aqueous solution of at least one alkali selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. Moreover, it is preferable that the density | concentration of aqueous alkali solution is 0.1 mass%-5 mass%. The temperature of the alkaline aqueous solution is preferably 10 ° C to 60 ° C, more preferably 15 ° C to 45 ° C, and further preferably 20 ° C to 35 ° C. The alkaline aqueous solution may contain zinc and other metals.
Specifically, for example, 50 g / L, 40 ° C. phosphoric acid aqueous solution, 0.5 g / L, 30 ° C. sodium hydroxide aqueous solution, 0.5 g / L, 30 ° C. potassium hydroxide aqueous solution, etc. are preferably used. It is done.
In addition, as a pH buffer solution, the buffer solution corresponding to the acid aqueous solution or alkali aqueous solution mentioned above can be used suitably.

  The immersion time in the acid aqueous solution or alkaline aqueous solution is preferably 8 minutes to 120 minutes, more preferably 10 minutes to 90 minutes, and further preferably 15 minutes to 60 minutes.

(Dry etching process)
For the dry etching treatment, for example, a gas species such as a Cl ₂ / Ar mixed gas is preferably used.

[First conductor filling step]
The first conductor filling step is a step of filling the first conductor into the through holes of the insulating base material having a plurality of through holes extending in the thickness direction as described above.
In the first conductor filling step, for example, after the barrier layer removing step described above, the first conductor is filled into the through holes of the anodic oxide film using a plating method. The first conductor constitutes a conductor.
<First conductor>
The first conductor is made of, for example, a first metal, and the metal filled as the first conductor is preferably a material having an electric resistivity of 10 ³ Ωcm or less. Specific examples thereof include gold ( Preferred examples include Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni), and zinc (Zn).
Among these, from the viewpoint of electrical conductivity, Cu, Au, Al, and Ni are preferable, Cu, Au, and Ni are more preferable, and Cu is further preferable.

<Filling method>
For example, an electrolytic plating method or an electroless plating method can be used as a plating method for filling the first conductor in the through hole.
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 period of time.

Therefore, when the metal is filled by the electrolytic plating method, it is necessary to provide a downtime during pulse electrolysis or constant potential electrolysis. The pause time is required to be 10 seconds or longer, and is 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 well-known plating solution can be used for a 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.

The plating solution preferably contains a surfactant.
As the surfactant, a known one can be used. Conventionally, sodium lauryl sulfate known as a surfactant to be added to the plating solution can be used as it is. Both hydrophilic (ionic, cationic, anionic, and zwitterionic) hydrophilic parts and nonionic (nonionic) parts can be used, but avoid the generation of bubbles on the surface of the plating object. A cationic surfactant is desirable. The concentration of the surfactant in the plating solution composition is desirably 1% by mass or less.

  In the electroless plating method, when the through hole is a hole made of a micropore having a high aspect, it takes a long time to completely fill the inside of the through hole with the metal. It is desirable to fill.

[Surface smoothing process]
After filling the through hole of the insulating base material with the first conductor, the surface of the insulating base material is polished to expose the first conductor on the surface of the insulating base material. In this case, for example, the first conductor and the insulating base material are flattened until they are in the same plane. For smoothing, for example, chemical mechanical polishing is used. For example, the surface of the insulating substrate and the end surface of the first conductor are polished so that the surface roughness is 20 nm or less. For example, the end point of the smoothing can be determined by using an optical change such as a change in reflected light of the insulating base material, or a frictional force change between the insulating base materials applied to the polishing apparatus used for the surface smoothing process. To detect.

[First conductor removing step]
The first conductor removing step is a step of removing a part of the first conductor on the smoothed surface side of the insulating base material to make the surface of the first conductor lower than the smoothed surface.
In the first conductor removing step, an etching solution that dissolves only the first conductor is used without dissolving the above-mentioned insulating base material, for example, an anodic oxide film such as aluminum. In the first conductor removing step, a nitric acid solution or an alkaline aqueous solution containing an amino acid can be used as an etching solution.

[Second Conductor Laminating Step]
A second conductor having a composition different from that of the first conductor is laminated on the surface of the first conductor. The method for laminating the second conductor is not particularly limited as long as the second conductor can be laminated, and the same method as that for filling the first conductor can be used. Similarly to the first conductor, the second conductor is formed by, for example, a plating method. As described above, since the second conductor 23 is laminated so as not to overflow from the through hole 14, the amount of lamination of the second conductor 23 is, for example, a plating process time when a plating method is used. It can be adjusted according to the plating process conditions.
The second conductor is not particularly limited as long as it is a metal different from the first conductor. For example, the metals mentioned in the first conductor can be used.

[Insulating base material removal process]
The insulating base material removing step is a step of removing a part of the smoothed surface side of the insulating base material and causing the first conductor and the second conductor to protrude from the insulating base material. The protrusion is formed by the insulating base material removing step. In the insulating base material removal step, the first conductor and the second conductor are 10 to 1000 nm from the surface of the insulating base material as the protrusions because the pressure-bonding property with the adherend such as the wiring board becomes good. It is preferable to project, and it is more preferable to project 50 to 500 nm.

  Partial removal of the insulating base material can be performed by, for example, using an acid aqueous solution or an alkaline aqueous solution that does not dissolve the first conductor and the second conductor described above but dissolves the insulating base material, for example, an anodic oxide film such as aluminum. On the other hand, it can be performed by bringing an anodic oxide film having a through hole filled with the first conductor and the second conductor into contact with each other. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred.

In the case of using an acid aqueous solution, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid or a mixture thereof. Especially, the aqueous solution which does not contain chromic acid is preferable at the point which is excellent in safety | security. The concentration of the acid aqueous solution is preferably 1 to 10% by mass. The temperature of the acid aqueous solution is preferably 25 to 60 ° C.
Moreover, when using alkaline aqueous solution, it is preferable to use the aqueous solution of the at least 1 alkali selected from the group which consists of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. The temperature of the alkaline aqueous solution is preferably 20 to 35 ° C.
Specifically, for example, 50 g / L, 40 ° C. phosphoric acid aqueous solution, 0.5 g / L, 30 ° C. sodium hydroxide aqueous solution or 0.5 g / L, 30 ° C. potassium hydroxide aqueous solution is preferably used. .
The immersion time in the acid aqueous solution or alkali aqueous solution is preferably 8 to 120 minutes, more preferably 10 to 90 minutes, and still more preferably 15 to 60 minutes. Here, the immersion time means the total of each immersion time when a short immersion treatment is repeated. In addition, you may perform a washing process between each immersion process.

[Substrate removal process]
A board | substrate removal process is a process of removing an aluminum substrate after an insulating base material removal process, when an insulating base material is an anodic oxide film with an aluminum substrate, for example. A method for removing the aluminum substrate is not particularly limited, and for example, a method for removing the aluminum substrate by dissolution, and the like are preferable.

<Dissolution of aluminum substrate>
For the above-described dissolution of the aluminum substrate, it is preferable to use a treatment liquid that hardly dissolves the anodic oxide film and easily dissolves aluminum.
Such a treatment solution has a dissolution rate with respect to aluminum of preferably 1 μm / min or more, more preferably 3 μm / min or more, and further preferably 5 μm / min or more. Similarly, the dissolution rate with respect to the anodic oxide film is preferably 0.1 nm / min or less, more preferably 0.05 nm / min or less, and further preferably 0.01 nm / min or less.
Specifically, the treatment liquid preferably contains at least one metal compound having a lower ionization tendency than aluminum and has a pH of 4 or less or 8 or more, and the pH is 3 or less or 9 or more. Is more preferable, and it is still more preferable that it is 2 or less or 10 or more.

The treatment solution for dissolving aluminum is based on an acid or alkaline aqueous solution, for example, manganese, zinc, chromium, iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper, mercury, silver, palladium, platinum Gold compounds (for example, chloroplatinic acid), fluorides thereof, chlorides thereof, and the like are preferable.
Among them, an acid aqueous solution base is preferable, and it is preferable to blend a chloride.
In particular, a treatment liquid (hydrochloric acid / mercury chloride) in which mercury chloride is blended with an aqueous hydrochloric acid solution and a treatment liquid (hydrochloric acid / copper chloride) in which copper chloride is blended with an aqueous hydrochloric acid solution are preferable from the viewpoint of treatment latitude.
The composition of the treatment solution for dissolving aluminum is not particularly limited, and for example, a bromine / methanol mixture, a bromine / ethanol mixture, aqua regia and the like can be used.

Moreover, 0.01-10 mol / L is preferable and, as for the acid or alkali concentration of the process liquid which melt | dissolves aluminum, 0.05-5 mol / L is more preferable.
Furthermore, the processing temperature using the processing solution for dissolving aluminum is preferably −10 ° C. to 80 ° C., and preferably 0 ° C. to 60 ° C.

Further, the above-described aluminum substrate is dissolved by bringing the aluminum substrate after the above-described metal filling step into contact with the above-described processing liquid. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred. The contact time at this time is preferably 10 seconds to 5 hours, and more preferably 1 minute to 3 hours.
In addition, when an insulating base material is an anodic oxide film with a titanium substrate, for example, it is a step of removing the titanium substrate.

[Resin layer forming step]
You may have a resin layer formation process from the reason for which the conveyance property of an anisotropically conductive member improves. Here, the resin layer forming step is the side where the first conductor and the second conductor that are the protruding portions are protruding after the insulating base material removing step and before the substrate removing step. In this step, a resin layer is provided on the surface of the insulating substrate.

  Specific examples of the resin material constituting the resin layer include an ethylene copolymer, a polyamide resin, a polyester resin, a polyurethane resin, a polyolefin resin, an acrylic resin, and a cellulose resin. However, from the viewpoint of transportability and ease of use as an anisotropic conductive member, the above resin layer is preferably a peelable film with an adhesive layer, and is adhesive by heat treatment or ultraviolet exposure treatment. It is more preferable that the film has a pressure-sensitive adhesive layer that becomes weak and peelable.

The above-mentioned film with an adhesive layer is not particularly limited, and examples thereof include a heat release resin layer and an ultraviolet (UV) release resin layer.
Here, the heat-peelable resin layer has adhesive strength at room temperature and can be easily peeled off only by heating, and many of them use mainly foamable microcapsules.
Specific examples of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer include a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a vinyl alkyl ether-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, and a polyamide-based pressure-sensitive adhesive. , Urethane adhesives, styrene-diene block copolymer adhesives, and the like.

Further, the UV peelable resin layer has a UV curable adhesive layer, and loses the adhesive force upon curing and can be peeled off.
Examples of the UV curable adhesive layer include a polymer in which a carbon-carbon double bond is introduced into the polymer side chain, main chain, or main chain terminal in the base polymer. As the base polymer having a carbon-carbon double bond, an acrylic polymer is preferably used as a basic skeleton.
Further, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization as necessary.
The base polymer having a carbon-carbon double bond can be used alone, but a UV curable monomer or oligomer can also be blended.
The UV curable adhesive layer is preferably used in combination with a photopolymerization initiator in order to be cured by UV irradiation. Photopolymerization initiators include benzoin ether compounds; ketal compounds; aromatic sulfonyl chloride compounds; photoactive oxime compounds; benzophenone compounds; thioxanthone compounds; camphorquinones; halogenated ketones; Phosphonate etc. are mentioned.

  Commercially available products of the heat-peelable resin layer include, for example, Intellimer [registered trademark] tape (manufactured by Nitta Co., Ltd.) such as WS5130C02 and WS5130C10; 3198, no. 3198LS, no. 3198M, no. 3198MS, no. 3198H, no. 3195, no. 3196, no. 3195M, no. 3195MS, no. 3195H, no. 3195HS, no. 3195V, no. 3195VS, no. 319Y-4L, no. 319Y-4LS, no. 319Y-4M, no. 319Y-4MS, no. 319Y-4H, no. 319Y-4HS, no. 319Y-4LSC, no. 31935MS, no. 31935HS, no. 3193M, no. Ribaalpha [registered trademark] series (manufactured by Nitto Denko Corporation) such as 3193MS;

  Examples of commercially available UV peelable resin layers include ELP DU-300, ELP DU-2385KS, ELP DU-2187G, ELP NBD-3190K, ELP UE-2091J and other ELEP holders (registered trademark) (Nitto Denko). Manufactured by); Adwill D-210, Adwill D-203, Adwill D-202, Adwill D-175, Adwill D-675 (all manufactured by Lintec Co., Ltd.); Sumitite [registered trademark] FLS N8000 series (Sumitomo Bakelite) UC353EP-110 (Furukawa Electric Co., Ltd.); Dicing tape such as ELP RF-7232DB, ELP UB-5133D (all manufactured by Nitto Denko Corporation); SP-575B-150, SP-541B -205, SP-5 7T-160, SP-537T-230 (all manufactured by Furukawa Electric Co.); and the like can be utilized back grinding tape.

  Moreover, the method of affixing the above-mentioned film with an adhesive layer is not specifically limited, It can affix using a conventionally well-known surface protection tape sticking apparatus and a laminator.

  Hereinafter, the configuration of the anisotropic conductive member 10 will be described more specifically.

[Insulating substrate]
The insulating base material is made of an inorganic material and is particularly limited as long as it has an electrical resistivity (about 10 ¹⁴ Ω · cm) comparable to that of an insulating base material that constitutes a conventionally known anisotropic conductive film or the like. Not.
In addition, “consisting of an inorganic material” is a rule for distinguishing from a polymer material constituting a resin layer described later, and is not a rule limited to an insulating base material composed only of an inorganic material, but an inorganic material. Is the main component (50% by mass or more).

  Examples of the insulating substrate include metal oxide substrates, metal nitride substrates, glass substrates, ceramic substrates such as silicon carbide, silicon nitride, carbon substrates such as diamond-like carbon, polyimide substrates, These composite materials are exemplified. In addition to this, for example, the insulating base material may be a film formed of an inorganic material containing 50% by mass or more of a ceramic material or a carbon material on an organic material having a through hole.

The insulating base material is preferably a metal oxide base material because a through-hole having a desired average opening diameter is formed as a through-hole, and a conductor serving as an electrical conduction path is easily formed.
The insulating base material is preferably composed of a metal anodized film, and more preferably composed of a valve metal anodized film.
Specific examples of the valve metal include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, magnesium, tungsten, bismuth, and antimony.
As described above, the insulating substrate is composed of, for example, a metal anodic oxide film, and among them, an aluminum anodic oxide film, which is a valve metal, or a titanium anodic oxide film is more preferable.
Aluminum is preferable as a constituent of the anodized film because it has good dimensional stability and is relatively inexpensive.
Titanium is a valve metal (valve metal) like aluminum, and has good dimensional stability, so that titanium is preferable as a constituent of the anodized film.

The thickness ht of the insulating substrate 12 is preferably in the range of 1 to 1000 μm, more preferably in the range of 5 to 500 μm, and still more preferably in the range of 10 to 300 μm. When the thickness of the insulating substrate is within this range, the handleability of the insulating substrate is improved.
The insulating substrate 12 has a thickness ht of 20 by cutting the insulating substrate 12 with a focused ion beam (FIB) in the thickness direction Dt, and measuring the cross section of the insulating substrate 12 with a field emission scanning electron microscope. It is an average value obtained by observing at a magnification of 10,000 times, obtaining the contour shape of the insulating base material 12, and measuring 10 points in the region corresponding to the thickness ht.
The thickness h of the anisotropic conductive member 10 is not particularly limited, and is appropriately determined depending on the thickness ht of the insulating base 12, the height H of the protrusions 16 b and 16 c, and the thickness of the resin layer 19. Is. The anisotropic conductive member 10 preferably has a total thickness variation (TTV) of 10 μm or less.
Here, the thickness h of the anisotropic conductive member 10 is obtained by observing the anisotropic conductive member 10 at a magnification of 200,000 times with a field emission scanning electron microscope to obtain the contour shape of the anisotropic conductive member 10. And it is the average value which measured 10 points | pieces about the area | region corresponded to thickness h.

The interval between the through holes 14 in the insulating substrate 12 is preferably 5 nm to 800 nm, more preferably 10 nm to 200 nm, and still more preferably 50 nm to 140 nm. When the interval between the through holes in the insulating base is within this range, the insulating base functions sufficiently as an insulating partition. The interval between the through holes is the same as the interval between the conductors.
Here, the interval between the through holes, that is, the interval between the conductors refers to the width w between adjacent conductors (see FIG. 1), and the cross section of the anisotropic conductive member is measured by a field emission scanning electron microscope. The average value observed at a magnification of 10,000 times and the width between adjacent conductors measured at 10 points.

[Aluminum substrate]
The aluminum substrate for forming the anodized film is not particularly limited, and specific examples thereof include a pure aluminum plate; an alloy plate containing aluminum as a main component and containing a small amount of foreign elements; low-purity aluminum (for example, a recycled material) ) On which a high-purity aluminum is vapor-deposited; a substrate on which the surface of silicon wafer, quartz, glass or the like is coated with high-purity aluminum by a method such as vapor deposition or sputtering; a resin substrate on which aluminum is laminated;

  Of the aluminum substrate, the surface on which the anodized film is provided by the anodizing treatment step has an aluminum purity of preferably 99.5% by mass or more, more preferably 99.9% by mass or more, and 99.99%. More preferably, it is at least mass%. When the aluminum purity is in the above range, the regularity of the through-hole arrangement is sufficient. For example, JIS (Japanese Industrial Standards) 1050 material is used for the aluminum substrate.

Moreover, in this invention, it is preferable that the surface of the one side which performs an anodizing process process among aluminum substrates is heat-processed, a degreasing process, and a mirror surface finishing process previously.
Here, about heat processing, a degreasing process, and a mirror surface finishing process, the process similar to each process described in the paragraphs [0044]-[0054] of Unexamined-Japanese-Patent No. 2008-270158 can be performed.
The mirror finish process before the anodizing process is, for example, electrolytic polishing, and for example, an electrolytic polishing liquid containing phosphoric acid is used for the electrolytic polishing.

[Titanium substrate]
The titanium substrate for forming the anodic oxide film is not particularly limited as long as a porous anodic oxide film can be formed. Titanium and titanium alloys defined in JIS (Japanese Industrial Standards) H4600: 2012 Can be used, but pure titanium is preferred.

〔conductor〕
The plurality of conductors are columnar members that penetrate in the thickness direction of the insulating base material and are electrically insulated from each other. As described above, the conductor includes a through portion, a base portion, and a tip portion.
The conductor has a protruding portion protruding from the surface of the insulating base material, and the height of the tip portion is uniform. Each conductor may be embedded in the resin layer as described above.

<Projection>
When the anisotropic conductive member and the electrode are electrically connected or physically joined by a technique such as crimping, the insulation of the surface direction when the protrusion is crushed can be sufficiently secured. The aspect ratio of the protruding portion (height of the protruding portion / diameter of the protruding portion) is preferably 0.5 or more and less than 50, more preferably 0.8 to 20, and further preferably 1 to 10. preferable.

In addition, from the viewpoint of following the surface shape of the semiconductor chip or semiconductor wafer to be connected, the height of the protruding portion of the conductor is preferably 100 nm to 500 nm.
Furthermore, from the viewpoint of suppressing contact between adjacent conductors due to external conductors falling down when they are electrically connected to the connection target of the semiconductor chip or semiconductor wafer, the tips of the tips of the projecting parts have the same height. That is, it is preferable that the tip of the tip of the protrusion is located on the same plane.
The height of the protruding portion of the conductor is an average obtained by observing the cross section of the anisotropic conductive member with a field emission scanning electron microscope at a magnification of 20,000 times and measuring the height of the protruding portion of the conductor at 10 points. Value.
The base portion is a portion protruding from the insulating base material, and no layer or the like is provided on the side surface, and a part of the tip portion is not disposed on the side surface of the base portion.
The tip is on the side in contact with the semiconductor chip or semiconductor wafer to be connected. The tip portion is for suppressing oxidation of the base portion, in particular, for suppressing oxidation of the end portion of the base portion, and ensures the conductivity of the conductor by the tip portion.
The equivalent circle diameter R of the base of the conductor is regarded as a cylinder, the cross section of the protrusion of the conductor is observed with a field emission scanning electron microscope, and the diameter of the base of the protrusion of the conductor is measured at 10 points. The average value.
The equivalent circle diameter Rs of the tip of the conductor is regarded as a cylinder, the cross section of the protrusion of the conductor is observed with a field emission scanning electron microscope, and the diameter of the tip of the protrusion of the conductor is 10 The average value measured at a point.
As described above, it is preferable that the second metal constituting the distal end portion 21 and the first metal constituting the base portion 20 have different ionization tendencies. In this case, as a specific metal combination, when the second metal constituting the tip portion 21 has a smaller ionization tendency than the first metal constituting the base portion 20, for example, when the second metal is Ni, the first metal Are Au, Cu, and Sn.
When the second metal constituting the tip 21 has a higher ionization tendency than the first metal, for example, when the second metal is Cu, the first metal is Sn.

<Other shapes>
The conductor is columnar, and the equivalent circle diameter R of the protrusions 16b and 16c is preferably more than 5 nm and 10 μm or less, more preferably 20 nm to 1000 nm, and even more preferably 100 nm or less. Moreover, it is preferable that the circle equivalent diameter Rs of the front-end | tip part 21 is the same as the circle equivalent diameter R of the protrusion parts 16b and 16c from a viewpoint of suppressing conduction | electrical_connection between adjacent conductors.

The conductors are present in a state where they are electrically insulated from each other by an insulating substrate, and the density is preferably ² million pieces / mm ² or more, and 10 million pieces / mm ² or more. Is more preferably 50 million pieces / mm ² or more, and most preferably 100 million pieces / mm ² or more.
Furthermore, the center-to-center distance p (see FIG. 2) between adjacent conductors is preferably 20 nm to 500 nm, more preferably 40 nm to 200 nm, and even more preferably 50 nm to 140 nm.

[Resin layer]
As described above, the resin layer is provided on the front and back surfaces of the insulating base material, and embeds the protruding portion of the conductor as described above. That is, the resin layer covers the protruding portion protruding from the insulating base material and protects the protruding portion.
The resin layer is formed by the above-described resin layer forming step. For example, the resin layer preferably exhibits fluidity in a temperature range of 50 ° C. to 200 ° C. and is cured at 200 ° C. or higher.
The resin layer is formed by the above-described resin layer forming step, but the composition of the resin agent shown below can also be used. Hereinafter, the composition of the resin layer will be described. The resin layer contains a polymer material. The resin layer may contain an antioxidant material.

<Polymer material>
The polymer material contained in the resin layer is not particularly limited, but the gap between the semiconductor chip or the semiconductor wafer and the anisotropic conductive member can be efficiently filled, and the adhesion with the semiconductor chip or the semiconductor wafer becomes higher. For the reason, a thermosetting resin is preferable.
Specific examples of the thermosetting resin include epoxy resins, phenol resins, polyimide resins, polyester resins, polyurethane resins, bismaleimide resins, melamine resins, and isocyanate resins.
Among them, it is preferable to use a polyimide resin and / or an epoxy resin because the insulation reliability is further improved and the chemical resistance is excellent.

<Antioxidant materials>
Specific examples of the antioxidant material contained in the resin layer include 1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, and 5-methyl-1,2, 3,4-tetrazole, 1H-tetrazole-5-acetic acid, 1H-tetrazole-5-succinic acid, 1,2,3-triazole, 4-amino-1,2,3-triazole, 4,5-diamino-1 , 2,3-triazole, 4-carboxy-1H-1,2,3-triazole, 4,5-dicarboxy-1H-1,2,3-triazole, 1H-1,2,3-triazole-4- Acetic acid, 4-carboxy-5-carboxymethyl-1H-1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2 , 4-triazole, -Carboxy-1,2,4-triazole, 3,5-dicarboxy-1,2,4-triazole, 1,2,4-triazole-3-acetic acid, 1H-benzotriazole, 1H-benzotriazole-5 Carboxylic acid, benzofuroxane, 2,1,3-benzothiazole, o-phenylenediamine, m-phenylenediamine, catechol, o-aminophenol, 2-mercaptobenzothiazole, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole , Melamine, and derivatives thereof.
Of these, benzotriazole and its derivatives are preferred.
Examples of benzotriazole derivatives include a hydroxyl group, an alkoxy group (eg, methoxy group, ethoxy group, etc.), an amino group, a nitro group, and an alkyl group (eg, methyl group, ethyl group, butyl group, etc.) on the benzene ring of benzotriazole. And substituted benzotriazole having a halogen atom (for example, fluorine, chlorine, bromine, iodine and the like). In addition, substituted naphthalenetriazole, substituted naphthalenebistriazole and the like substituted in the same manner as naphthalenetriazole and naphthalenebistriazole can also be mentioned.

  Other examples of the antioxidant material contained in the resin layer include general antioxidants, higher fatty acids, higher fatty acid copper, phenolic compounds, alkanolamines, hydroquinones, copper chelating agents, organic amines, organic An ammonium salt etc. are mentioned.

  Although content of the antioxidant material contained in a resin layer is not specifically limited, 0.0001 mass% or more is preferable with respect to the total mass of a resin layer, and 0.001 mass% or more is more preferable from a viewpoint of the anticorrosion effect. Moreover, from the reason for obtaining an appropriate electrical resistance in this joining process, 5.0 mass% or less is preferable and 2.5 mass% or less is more preferable.

<Migration prevention material>
The resin layer contains a migration prevention material because the insulation reliability is further improved by trapping metal ions, halogen ions, and metal ions derived from the semiconductor chip and the semiconductor wafer that can be contained in the resin layer. Is preferred.

As the migration preventing material, for example, an ion exchanger, specifically, a mixture of a cation exchanger and an anion exchanger, or only a cation exchanger can be used.
Here, the cation exchanger and the anion exchanger can be appropriately selected from, for example, an inorganic ion exchanger and an organic ion exchanger described later.

(Inorganic ion exchanger)
Examples of the inorganic ion exchanger include metal hydrated oxides typified by hydrous zirconium oxide.
As the types of metals, for example, in addition to zirconium, iron, aluminum, tin, titanium, antimony, magnesium, beryllium, indium, chromium, bismuth, and the like are known.
Among these, zirconium-based ones have exchangeability for the cationic Cu ²⁺ and Al ³⁺ . Also, iron-based ones have exchange ability for Ag ⁺ and Cu ²⁺ . Similarly, those based on tin, titanium and antimony are cation exchangers.
On the other hand, those of bismuth-based, anion Cl ^- has exchange capacity for.
Zirconium-based ones exhibit anion exchange capacity depending on the production conditions. The same applies to aluminum-based and tin-based ones.
As inorganic ion exchangers other than these, synthetic compounds such as acid salts of polyvalent metals typified by zirconium phosphate, heteropolyacid salts typified by ammonium molybdophosphate, insoluble ferrocyanides, and the like are known.
Some of these inorganic ion exchangers are already on the market, and for example, various grades under the trade name IXE “IXE” of Toa Gosei Co., Ltd. are known.
In addition to synthetic products, natural product zeolites or inorganic ion exchanger powders such as montmorillonite can also be used.

(Organic ion exchanger)
Examples of the organic ion exchanger include crosslinked polystyrene having a sulfonic acid group as a cation exchanger, and those having a carboxylic acid group, a phosphonic acid group, or a phosphinic acid group.
Examples of the anion exchanger include crosslinked polystyrene having a quaternary ammonium group, a quaternary phosphonium group, or a tertiary sulfonium group.

These inorganic ion exchangers and organic ion exchangers may be appropriately selected in consideration of the type of cation to be captured, the type of anion, and the exchange capacity for the ion. Of course, it goes without saying that an inorganic ion exchanger and an organic ion exchanger may be mixed and used.
Since the manufacturing process of an electronic device includes a heating process, an inorganic ion exchanger is preferable.

  The mixing ratio of the migration preventing material and the above-described polymer material is preferably, for example, 10% by mass or less for the migration preventing material and 5% by mass or less for the migration preventing material from the viewpoint of mechanical strength. More preferably, the migration preventing material is further preferably 2.5% by mass or less. Moreover, it is preferable that a migration prevention material shall be 0.01 mass% or more from a viewpoint of suppressing the migration at the time of joining a semiconductor chip or a semiconductor wafer, and an anisotropic conductive member.

<Inorganic filler>
The resin layer preferably contains an inorganic filler.
The inorganic filler is not particularly limited and can be appropriately selected from known ones. For example, kaolin, barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, gas phase method silica, and amorphous silica , Crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, aluminum nitride, zirconium oxide, yttrium oxide, silicon carbide, silicon nitride and the like.

In order to prevent the inorganic filler from entering between the conductors and improve the conduction reliability, it is preferable that the average particle diameter of the inorganic filler is larger than the interval between the conductors.
The average particle size of the inorganic filler is preferably 30 nm to 10 μm, and more preferably 80 nm to 1 μm.
Here, the average particle size is defined as a primary particle size measured by a laser diffraction / scattering particle size measuring device (Microtrack MT3300 manufactured by Nikkiso Co., Ltd.).

<Curing agent>
The resin layer may contain a curing agent.
When it contains a curing agent, it does not use a solid curing agent at room temperature, but contains a curing agent that is liquid at room temperature, from the viewpoint of suppressing poor bonding with the surface shape of the semiconductor chip or semiconductor wafer to be connected. Is more preferable.
Here, “solid at normal temperature” means solid at 25 ° C., for example, a substance having a melting point higher than 25 ° C.

  Specific examples of the curing agent include aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives such as 4-methylimidazole, dicyandiamide, tetramethylguanidine, thiourea-added amine, and methyl. Examples include carboxylic acid anhydrides such as hexahydrophthalic anhydride, carboxylic acid hydrazides, carboxylic acid amides, polyphenol compounds, novolak resins, polymercaptans, and the like. Can be used. In addition, a hardening | curing agent may be used individually by 1 type, and may use 2 or more types together.

  The resin layer may contain various additives such as a dispersant, a buffer agent, and a viscosity modifier that are generally added to the resin insulating film of the semiconductor package as long as the characteristics are not impaired.

<Shape>
For the reason of protecting the conductor, the thickness of the resin layer is preferably larger than the height of the protruding portion of the conductor and is 1 μm to 5 μm.

(Electronic device)
Hereinafter, an electronic device using the anisotropic conductive member 10 (see FIG. 1 and the like) will be described.
FIG. 16 is a schematic diagram illustrating a first example of an electronic device according to an embodiment of the present invention. FIG. 17 is a schematic cross-sectional view showing an example of the configuration of the terminals of the semiconductor element of the electronic device according to the embodiment of the present invention. FIG. 18 is a schematic diagram illustrating a second example of the electronic device according to the embodiment of the invention. FIG. 19 is a schematic diagram illustrating a third example of the electronic device according to the embodiment of the invention. FIG. 20 is a schematic diagram illustrating a fourth example of the electronic device according to the embodiment of the invention. The joined body constitutes a part of the electronic device. A semiconductor element to be described later is, for example, a member having a conductive region of a bonded body and bonded to an anisotropic conductive member. The conductive region corresponds to a terminal or the like responsible for the conduction of the semiconductor element.

  As in the electronic device 30 shown in FIG. 16, the semiconductor element 32 and the semiconductor element 34 are joined in the stacking direction Ds via the anisotropic conductive member 10 exhibiting anisotropic conductivity, and the semiconductor element 32 and the semiconductor element 34. May be electrically connected. The anisotropic conductive member 10 includes a conductor 16 (see FIG. 1) that conducts in the stacking direction Ds, and functions as a TSV (Through Silicon Via). The anisotropic conductive member 10 can also be used as an interposer.

For example, as shown in FIG. 17, the semiconductor elements 32 and 34 each have a plurality of terminals 50. The plurality of terminals 50 are for joining semiconductors. The terminal 50 includes a terminal 50a that electrically connects the semiconductor elements 32 and 34, and a terminal 50b that joins the semiconductor elements 32 and 34 but does not electrically connect them. The terminal 50a is for taking out signals from the semiconductor elements 32 and 34 to the outside. The terminal 50 b is for radiating the heat generated in the semiconductor elements 32 and 34 to the outside or maintaining the bonding strength of the electronic device 30.
The terminal 50 has a configuration shown in FIG. 17, for example. As shown in FIG. 17, the semiconductor elements 32 and 34 include a semiconductor layer 52, a rewiring layer 54, and a passivation layer 56. The rewiring layer 54 and the passivation layer 56 are electrically insulated insulating layers. On the surface 52a of the semiconductor layer 52, an element region (not shown) in which a circuit or the like that exhibits a specific function is formed. The element region will be described later. The surface 52a of the semiconductor layer 52 corresponds to the surface on which the semiconductor terminals 50 are provided.
A rewiring layer 54 is provided on the surface 52 a of the semiconductor layer 52. In the rewiring layer 54, wiring 57 that is electrically connected to the element region of the semiconductor layer 52 is provided. A pad 58 is provided on the wiring 57, and the wiring 57 and the pad 58 are electrically connected. The wiring 57 and the pad 58 can exchange signals with the element region, and supply voltage or the like to the element region.

A passivation layer 56 is provided on the surface 54 a of the rewiring layer 54. In the passivation layer 56, a terminal 50 a is provided on a pad 58 provided on the wiring 57. The terminal 50a is electrically connected to the semiconductor layer 52.
The rewiring layer 54 is not provided with the wiring 57 but is provided with only the pad 58. A terminal 50 b is provided on a pad 58 that is not provided on the wiring 57. The terminal 50b is not electrically connected to the semiconductor layer 52.

  The end face 50c of the terminal 50a and the end face 50c of the terminal 50b are both coincident with the surface 56a of the passivation layer 56 and are in a so-called flush state, and the terminals 50a and 50b protrude from the surface 56a of the passivation layer 56. Absent. The terminals 50a and 50b shown in FIG. 17 are flush with the surface 56a of the passivation layer 56, for example, by polishing.

The terminals 50a and 50b are not limited to being flush with the surface 56a of the passivation layer 56, and may protrude from the surface 56a of the passivation layer 56. In this case, the recess amount that is the protrusion amount of the terminal 50a and the terminal 50b with respect to the surface 56a of the passivation layer 56 is, for example, 200 nm or more and 1 μm or less.
If the recess amount is less than 200 nm, it is substantially the same as the non-projecting configuration shown in FIG. 17, and it is necessary to polish with high accuracy. On the other hand, when the recess amount exceeds 1 μm, it is the same as a general configuration in which a pad electrode is provided, and it is necessary to join using a solder ball or the like.
Since the terminals 50a and 50b protrude from the surface 56a of the passivation layer 56, a resin layer (not shown) for protecting the terminals 50a and 50b may be provided on the surface 56a of the passivation layer 56. .

The above-described recess amount is obtained by obtaining an image of a cross section including the terminal 50a and the terminal 50b in the semiconductor elements 32 and 34, obtaining an outline of the terminal 50a and an outline of the terminal 50b by image analysis, and obtaining an end face 50c and a terminal of the terminal 50a. The end face 50c of 50b is detected. It can be obtained by obtaining the distance from the surface 56a of the passivation layer 56 to the end face 50c of the terminal 50a and the distance from the end face 50c of the terminal 50b.
The end surface 50c of the terminal 50a and the end surface 50c of the terminal 50b are both surfaces that are farthest from the surface 56a of the passivation layer 56, and are generally referred to as upper surfaces.

The semiconductor layer 52 is not particularly limited as long as it is a semiconductor, and is composed of silicon or the like, but is not limited thereto, and may be silicon carbide, germanium, gallium arsenide, gallium nitride, or the like. Good.
The rewiring layer 54 is made of an electrically insulating material such as polyimide.
The passivation layer 56 is also made of an electrically insulating material such as silicon nitride (SiN) or polyimide.
The wiring 57 and the pad 58 are made of a conductive material, and are made of, for example, copper, copper alloy, aluminum, aluminum alloy, or the like.

The terminal 50a and the terminal 50b are made of a conductive material like the wiring 57 and the pad 58, and are made of, for example, a metal or an alloy. Specifically, the terminal 50a and the terminal 50b are made of, for example, copper, copper alloy, aluminum, aluminum alloy, or the like.
The terminal 50a and the terminal 50b are not limited to being made of metal or alloy as long as they have conductivity, and are used for what are called terminals or electrode pads in the semiconductor element field. Materials can be used as appropriate.

In addition to the configuration shown in FIG. 16, the electronic device 30 includes, for example, the semiconductor element 32, the semiconductor element 34, and the semiconductor element 36 in the stacking direction Ds via the anisotropic conductive member 10 like the electronic device 30 shown in FIG. 18. It is good also as a structure laminated | stacked and joined to and electrically connected.
Further, like the electronic device 30 shown in FIG. 19, the semiconductor element 32, the semiconductor element 34, and the semiconductor element 36 are stacked in the stacking direction Ds using the interposer 37 and the anisotropic conductive member 10, and An electrically connected configuration may be used.

Further, the electronic device 30 shown in FIG. 20 may function as an optical sensor. In the electronic device 30 illustrated in FIG. 20, the semiconductor element 40 and the sensor chip 42 are stacked in the stacking direction Ds via the anisotropic conductive member 10. The sensor chip 42 is provided with a lens 44.
The semiconductor element 40 is formed with a logic circuit, and its configuration is not particularly limited as long as a signal obtained by the sensor chip 42 can be processed.
The sensor chip 42 has an optical sensor that detects light. The optical sensor is not particularly limited as long as it can detect light. For example, a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor is used.
In the electronic device 30 shown in FIG. 20, the semiconductor element 40 and the sensor chip 42 are connected via the anisotropic conductive member 10. However, the present invention is not limited to this, and the semiconductor element 40 and the sensor chip 42 are connected to each other. The structure which joins directly may be sufficient.
The configuration of the lens 44 is not particularly limited as long as it can collect light on the sensor chip 42. For example, a lens called a microlens is used.

The semiconductor element 32, the semiconductor element 34, and the semiconductor element 36 described above have element regions (not shown).
The element region is a region where various element constituent circuits such as capacitors, resistors, and coils for functioning as electronic elements are formed. In the element region, for example, a memory circuit such as a flash memory, a region where a logic circuit such as a microprocessor and an FPGA (field-programmable gate array) is formed, a communication module such as a wireless tag, and wiring are formed. There are areas. In addition to this, a transmission circuit or MEMS (Micro Electro Mechanical Systems) may be formed in the element region. The MEMS is, for example, a sensor, an actuator, an antenna, or the like. Examples of the sensor include various sensors such as acceleration, sound, and light.

As described above, an element configuration circuit or the like is formed in the element region, and a rewiring layer (not shown) is provided in the semiconductor element, for example.
In a stacked device, for example, a combination of a semiconductor element having a logic circuit and a semiconductor element having a memory circuit can be used. Further, all the semiconductor elements may have a memory circuit, and all the semiconductor elements may have a logic circuit. Further, the combination of the semiconductor elements in the electronic device 30 may be a combination of a sensor, an actuator, an antenna, and the like, a memory circuit, and a logic circuit, and is appropriately determined according to the use of the electronic device 30 and the like.

[Semiconductor element]
The semiconductor element is not particularly limited, and other than those described above, for example, logic LSI (Large Scale Integration) (for example, ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), ASSP (Application Specific Standard Product). )), Microprocessor (for example, CPU (Central Processing Unit), GPU (Graphics Processing Unit), etc.), memory (for example, DRAM (Dynamic Random Access Memory), HMC (Hybrid Memory Cube), MRAM (Magnetic RAM: magnetic memory) ) And PCM (Phase-Change Memory), ReRAM (Resistive RAM), FeRAM (Ferroelectric RAM), flash memory (NAND (Not AND) flash), etc.), LED (Light Emitting Diode), (for example, micro flash for portable terminals, in-vehicle use Projector light source, LCD backlight, general lighting, etc.), power device, analog IC (Integrated Circuit), (eg DC (Direct Current) -DC (Direct Current) converter, insulated gate bipolar transistor (IGBT), etc.), MEMS (Micro Electro Mechanical Systems) (for example, acceleration sensors, pressure sensors, vibrators, gyro sensors, etc.), wireless (for example, GPS (Global Positioning System), FM (Frequency Modulation), NFC (Nearfield communication), RFEM (RF Expansion) Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), etc.), discrete element, BSI (Back Side Illumination), CIS (Contact Image Sensor), camera module, CMOS (Complementary Metal Oxide Semiconductor), Passive device, SAW (Surface A Examples include a coustic wave (RF) filter, an RF (Radio Frequency) filter, an RFIPD (Radio Frequency Integrated Passive Devices), and a BB (Broadband).
For example, a single semiconductor element is completed, and the semiconductor element alone exhibits a specific function such as a circuit or a sensor.

The electronic device is not limited to a one-to-multiple form in which a plurality of semiconductor elements are joined to one semiconductor element, but a plurality of forms in which a plurality of semiconductor elements and a plurality of semiconductor elements are joined. Multiple forms may be used.
21 is a schematic diagram showing a fifth example of the electronic device according to the embodiment of the present invention, FIG. 22 is a schematic diagram showing a sixth example of the electronic device according to the embodiment of the present invention, and FIG. FIG. 24 is a schematic diagram illustrating a seventh example of the electronic device according to the embodiment of the invention, and FIG. 24 is a schematic diagram illustrating the eighth example of the electronic device according to the embodiment of the present invention.

For example, as shown in FIG. 21, the semiconductor element 34 and the semiconductor element 36 are bonded to one semiconductor element 32 using the anisotropic conductive member 10 and are electrically connected. The electronic device 60 in a form connected to is illustrated. The semiconductor element 32 may have an interposer function.
For example, a plurality of devices such as a logic chip having a logic circuit and a memory chip can be stacked on a device having an interposer function. In this case, bonding can be performed even if the electrode size is different for each device.
In the electronic device 61 shown in FIG. 22, the electrodes 68 are not the same in size but are mixed in different sizes. The element 34 and the semiconductor element 36 are joined and electrically connected. Further, the semiconductor element 66 is joined to the semiconductor element 34 using the anisotropic conductive member 10 and is electrically connected thereto. The semiconductor element 67 is joined and electrically connected across the semiconductor element 34 and the semiconductor element 36 using the anisotropic conductive member 10.

  Further, as in the electronic device 62 shown in FIG. 23, the semiconductor element 34 and the semiconductor element 36 are joined and electrically connected to one semiconductor element 32 using the anisotropic conductive member 10. Yes. Further, the semiconductor element 66 and the semiconductor element 67 are bonded to the semiconductor element 34 using the anisotropic conductive member 10, the semiconductor element 71 is bonded to the semiconductor element 36 using the anisotropic conductive member 10, and electrically A connected configuration can also be adopted.

In the case of the configuration described above, a light emitting element such as a VCSEL (Vertical Cavity Surface Emitting Laser) and a light receiving element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor are stacked on the device surface including the optical waveguide. This makes it possible to support silicon photonics that assumes high frequencies.
For example, as in the electronic device 63 shown in FIG. 24, the semiconductor element 34 and the semiconductor element 36 are joined and electrically connected to one semiconductor element 32 using the anisotropic conductive member 10. Yes. Further, the semiconductor element 66 and the semiconductor element 67 are bonded to the semiconductor element 34 using the anisotropic conductive member 10, the semiconductor element 71 is bonded to the semiconductor element 36 using the anisotropic conductive member 10, and electrically It is connected. The semiconductor element 32 is provided with an optical waveguide 73. The semiconductor element 36 is provided with a light emitting element 75, and the semiconductor element 34 is provided with a light receiving element 76. The light Lo output from the light emitting element 75 of the semiconductor element 36 passes through the optical waveguide 73 of the semiconductor element 32 and is emitted as the outgoing light Ld to the light receiving element 76 of the semiconductor element 34. Thereby, it can respond to the above-mentioned silicon photonics.
In the anisotropic conductive member 10, a hole 72 is formed at a location corresponding to the optical path of the light Lo and the emitted light Ld.

  Further, the anisotropic conductive member 10 can be used as an interposer that is bonded to a silicon interposer or a glass interposer in addition to the above-described electronic device and that simplifies the wiring process. Furthermore, it can also be used for connection between a printed wiring board or a flexible board and a rigid board, connection between flexible boards, connection between rigid boards, and the like. In addition, the anisotropic conductive member 10 can be used as a probe and a heat sink of an inspection device.

  In addition, it does not specifically limit as a final product in which the conjugate | zygote using the anisotropic conductive member 10 and an electronic device are used, For example, smart TV, a mobile communication terminal, a mobile phone, a smart phone, a tablet terminal, desktop PC ( Personal computer), notebook PC, network equipment (router, switching), wired infrastructure equipment, digital camera, game console, controller, data center, server, HPC (high-performance computing), graphic card, network server, storage, chipset , In-vehicle (electronic control equipment, driving support system), car navigation, PND (Personal Navigation Device), lighting (general lighting, in-vehicle lighting, LED lighting, OLED (Organic Light Emitting Diode) lighting), TV, display, display panel ( LCD panel, organic EL panels, electronic paper), music playback terminals, industrial equipment, industrial robots, inspection equipment, medical equipment, household appliances such as household appliances for domestic use and household appliances, space equipment, aircraft equipment, and wearable devices are suitable. It is mentioned in.

  The present invention is basically configured as described above. As described above, the anisotropic conductive member, the method for manufacturing the anisotropic conductive member, the joined body, and the electronic device of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiment, and departs from the gist of the present invention. It goes without saying that various improvements or changes may be made without departing from the scope.

The features of the present invention will be described more specifically with reference to the following examples. The materials, reagents, substance amounts and ratios thereof, and operations shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples.
In this example, the bonding properties, adjacent conduction and conduction resistance were evaluated for Examples 1 to 11 and Comparative Examples 1 to 3 shown in Table 1 and Table 2 below. The evaluation results of bondability, adjacent conduction and conduction resistance are shown in Table 3 below. In Table 1 below, M1 represents the first metal and M2 represents the second metal. In Tables 1 and 2 below, “-” indicates that there is no corresponding item.
Next, description will be made on the evaluation items, such as bondability, adjacent conduction and conduction resistance.

(Evaluation of bondability)
The bondability was evaluated by measuring the shear strength using a universal bond tester Dage-4000 (manufactured by Nordson Advanced Technology Co., Ltd.).
The joining property was obtained by joining an anisotropic conductive member to a TEG chip (Test Element Group chip) shown below. In this state, the shear strength was measured, and the bonding strength value per unit area of the anisotropic conductive member was determined from the obtained breaking load. Bondability was evaluated according to the following evaluation criteria based on the bond strength value.
“A”: 20 MPa ≦ joining strength “B”: 10 MPa ≦ joining strength <20 MPa
“C”: bonding strength <10 MPa

<TEG chip>
A TEG chip (Test Element Group chip) having a Cu pad and an interposer were prepared. These include a daisy chain pattern for measuring conduction resistance and a comb pattern for measuring insulation resistance. These insulating layers are SiN. The TEG chip was prepared with a chip size of 8 mm square and a ratio of the electrode area (copper post) to the chip area of 25%. The TEG chip corresponds to a semiconductor chip. Since the interposer includes lead-out wiring around it, a chip size of 10 mm square was prepared.
Next, the TEG chip, the anisotropic conductive member, and the interposer were bonded together under the conditions of a temperature of 270 ° C. for 10 minutes using a chip bonder (DB250, manufactured by Kasuya Kogyo Co., Ltd.) in this order. At this time, the positions of the TEG chip and the Cu pad of the interposer were aligned and joined by using alignment marks formed in advance at the corners of the chip.

  Hereinafter, the short circuit and the conduction resistance will be described. The above-described TEG chip (Test Element Group chip) was used for evaluation of adjacent conduction and evaluation of conduction resistance.

(Evaluation of adjacent conduction)
A resistance measurement signal line was joined to the lead-out wiring pad of the interposer comb-teeth pattern portion by soldering, and continuity evaluation was performed at room temperature and in the atmosphere.
Based on the result of resistance value, it evaluated by the evaluation criteria shown below.
“A”: resistance value is 0.1 times or more of design resistance “B”: resistance value is 0.01 times or more and less than 0.1 times of design resistance “C”: resistance value is 0.001 times or more of design resistance Less than 0.01 times "D": Resistance value is less than 0.001 times design resistance

(Evaluation of conduction resistance)
Signal wires for resistance measurement were joined to the lead-out wiring pads of the daisy chain pattern portion of the interposer with solder, and continuity evaluation was performed at room temperature and in the atmosphere.
Based on the result of resistance value, it evaluated by the evaluation criteria shown below.
“A”: resistance value is less than 10 times the design resistance “B”: resistance value is 10 to 100 times the design resistance “C”: resistance value is 100 to 1000 times the design resistance “D”: resistance Value is more than 1000 times the design resistance

Hereinafter, Examples 1 to 11 and Comparative Examples 1 to 3 will be described.
Example 1

[Anisotropic conductive member]
<Preparation of aluminum substrate>
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.005 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: It contains 0.03% by mass, and the balance is prepared using Al and an inevitable impurity aluminum alloy. After the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is converted into DC (Direct Chill). ) Made by casting.
Next, the surface was shaved with a chamfering machine with an average thickness of 10 mm, soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., the thickness was 2.7 mm using a hot rolling mill. A rolled plate was used.
Further, heat treatment was performed at 500 ° C. using a continuous annealing machine, and then finished by cold rolling to a thickness of 1.0 mm to obtain a JIS (Japanese Industrial Standards) 1050 aluminum substrate.
An aluminum substrate was formed into a wafer shape having a diameter of 200 mm (8 inches) and then subjected to the following processes.

<Electropolishing treatment>
The above-mentioned aluminum substrate was subjected to electropolishing using an electropolishing liquid having the following composition under conditions of a voltage of 25 V, a liquid temperature of 65 ° C., and a liquid flow rate of 3.0 m / min.
The cathode was a carbon electrode, and GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.) was used as the power source. Further, the flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by ASONE Corporation).
(Electrolytic polishing liquid composition)
-660 mL of 85% by mass phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
・ Pure water 160mL
・ Sulfuric acid 150mL
・ Ethylene glycol 30mL

<Anodizing process>
Next, the aluminum substrate after the electrolytic polishing treatment was subjected to an anodizing treatment by a self-ordering method according to the procedure described in JP-A-2007-204802 to obtain an anodized film serving as an insulating substrate.
The aluminum film after the electropolishing treatment was subjected to a pre-anodizing treatment for 5 hours with an electrolytic solution of 0.50 mol / L oxalic acid at a voltage of 40 V, a liquid temperature of 16 ° C., and a liquid flow rate of 3.0 m / min. .
Thereafter, a film removal treatment was performed in which the aluminum film after the pre-anodizing treatment was immersed in a mixed aqueous solution (liquid temperature: 50 ° C.) of 0.2 mol / L chromic anhydride and 0.6 mol / L phosphoric acid for 12 hours.
Thereafter, reanodization treatment was performed for 3 hours and 45 minutes with an electrolyte solution of 0.50 mol / L oxalic acid under conditions of a voltage of 40 V, a liquid temperature of 16 ° C., and a liquid flow rate of 3.0 m / min, and a film thickness of 30 μm. An anodic oxide film was obtained.
In both the pre-anodizing treatment and the re-anodizing treatment, the cathode was a stainless electrode, and the power supply was GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.). Further, NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) was used as the cooling device, and Pair Stirrer PS-100 (manufactured by EYELA Tokyo Rika Kikai Co., Ltd.) was used as the stirring and heating device. Furthermore, the flow rate of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by ASONE Corporation).

<Barrier layer removal process>
Next, electrolytic treatment (electrolytic removal treatment) was performed using the same treatment liquid and treatment conditions as in the above-described anodizing treatment while the voltage was continuously lowered from 40 V to 0 V at a voltage drop rate of 0.2 V / sec.
Thereafter, an etching treatment (etching removal treatment) is performed by immersing in 5% by mass phosphoric acid at 30 ° C. for 30 minutes to remove the barrier layer at the bottom of the micropore of the anodized film, and through the micropore which is a through hole. The aluminum substrate was exposed.

Here, the average opening diameter of the micropores present in the anodized film after the barrier layer removing step was 60 nm. In addition, the average opening diameter was calculated as an average value obtained by taking a surface photograph (magnification 50000 times) with an FE-SEM (Field emission-Scanning Electron Microscope) and measuring 50 points.
The average thickness of the anodic oxide film after the barrier layer removing step was 18 μm. The average thickness is an average obtained by cutting the anodized film with FIB (Focused Ion Beam) in the thickness direction, photographing a surface photograph (magnification 50000 times) with FE-SEM, and measuring 10 points. Calculated as value.
The density of micropores present in the anodic oxide film was about 100 million / mm ² . The micropore density was measured and calculated by the method described in paragraphs [0168] and [0169] of JP-A-2008-270158.
Further, the degree of ordering of the micropores present in the anodic oxide film was 92%. The degree of ordering was calculated by taking a photograph (magnification: 20000 times) with FE-SEM, measuring it by the method described in paragraphs [0024] to [0027] of JP-A-2008-270158.

<First conductor filling step>
Next, electrolytic plating was performed using an aluminum substrate as a cathode and platinum as a positive electrode, and copper was filled as a first conductor.
Specifically, copper was filled in the micropores of the anodized film by performing constant current electrolysis using a copper plating solution having the composition shown below.
Here, the constant current electrolysis is performed by cyclic voltammetry in a plating solution using a power source (HZ-3000) manufactured by Hokuto Denko Co., Ltd. using a plating apparatus manufactured by Yamamoto Metal Testing Co., Ltd. After confirming the potential, the treatment was performed under the following conditions.
(Copper plating composition and conditions)
・ Copper sulfate 100g / L
・ Sulfuric acid 50g / L
・ Hydrochloric acid 15g / L
・ Temperature 25 ℃
・ Current density 10A / dm ²

<Surface smoothing process>
Next, the surface of the anodic oxide film filled with copper was subjected to CMP (Chemical Mechanical Polishing) to polish the anodic oxide film by 5 μm. This smoothed the surface of the anodized film and exposed the filled copper.
As a CMP slurry, PNANERLITE-7000 manufactured by Fujimi Incorporated was used.

The surface of the anodic oxide film after filling with copper is observed with FE-SEM, and the presence or absence of sealing by metal in 1000 micropores is observed to determine the sealing rate (number of sealed micropores / 1000). The calculated value was 80%.
In addition, the anodized film after filling with copper was cut with FIB in the thickness direction, and a cross-sectional photograph of the surface was taken with FE-SEM (50000 times magnification), and the inside of the micropore was confirmed. It was found that the inside of the sealed micropore was completely filled with metal.

<First conductor removing step>
A part of the copper filled in the micropores was removed by 300 nm by treating with 30% nitric acid aqueous solution for 30 seconds, and the surface of the copper was made lower than the smoothed surface.
<Second conductor lamination step>
Sn (tin) was laminated as a second conductor on the surface of copper.
Specifically, after using a commercially available electroless Sn (tin) plating solution (Substar SN-5: manufactured by Okuno Seiyaku Kogyo Co., Ltd.) as specified, treating the solution at 50 ° C. for 10 seconds And washed with pure water. At this time, the height of the second conductor (tin) laminated on the first conductor (copper) in the micropore was 20 nm.

<Insulating base material removal process>
The structure is immersed in an aqueous potassium hydroxide solution (concentration: 0.1 mol / L, liquid temperature: 20 ° C.), and the immersion time is set so that the height of the protruding portion of the conductor is 100 nm (see Table 1 below). The surface of the aluminum anodic oxide film was selectively dissolved. Thereby, the base part of copper and the protrusion part of the front-end | tip part of Sn (tin) were formed.
<Substrate removal process>
Next, the aluminum substrate was dissolved and removed by immersing it in a 20% by mass mercury chloride aqueous solution (raised) at 20 ° C. for 3 hours to expose the back surface of the anodized film.

<Back side smoothing process>
Next, the back surface of the anodized film was subjected to CMP (Chemical Mechanical Polishing), and the anodized film was polished for 5 μm to smooth the back surface. As a result, copper was exposed on the back surface of the anodized film.
As a CMP slurry, PNANERLITE-7000 manufactured by Fujimi Incorporated was used.
<Back side first conductor removal step>
On the back side of the anodized film, a part of copper filled in the micropores is treated for 10 minutes using a mixed solution of 10% hydrogen peroxide and 10% glycine in the same manner as the front surface of the anodized film. This removed 300 nm, and the surface of the copper was made lower than the smoothed surface.
<Back side second conductor lamination step>
About the back surface side of the anodic oxide film, Sn (tin) was laminated | stacked 20 nm on the copper surface by the method similar to the surface of the anodic oxide film.
<Back side insulating base material removal process>
About the back surface side of the anodized film, the back surface of the anodized film was selectively dissolved so that the height of the protruding portion of the conductor was 100 nm (see Table 1 below). Thereby, the thickness of the insulating base material was 8 micrometers, and the anisotropic conductive member which has a protrusion part on both surfaces of an insulating base material was obtained.
In Example 1, a drying step is provided between the first conductor removing step and the second conductor laminating step, and after removing the first conductor, the surface of copper is dried and Sn is deposited on the surface of copper. (Tin) was laminated.

(Example 2)
Example 2 is different from Example 1 except that the protrusion is provided only on one side of the insulating base material and that there is no drying step between the first conductor removing step and the second conductor laminating step. Same as above.
In Example 2, the first conductor was removed between the first conductor removal step and the second conductor lamination step, and then the copper surface was dipped in pure water without being dried. Sn (tin) was laminated on the surface.

(Example 3)
In Example 3, the thickness of the insulating substrate is 15 μm, the point where the filled metal is changed from copper to nickel (Ni), and between the first conductor removing step and the second conductor laminating step. The same as Example 1 except that there was no drying step.
In the nickel filling method, a nickel plating solution having the following composition was used, and nickel was filled into the micropores by performing constant current electrolysis.
<Nickel plating solution composition>
・ Nickel sulfate 300g / L
・ Nickel chloride 60g / L
・ Boric acid 40g / L
・ Temperature 50 ℃
・ Current density 5A / dm ²
In Example 3, after removing the first conductor between the first conductor removing step and the second conductor laminating step, the nickel surface was dried without being dried in the state of being immersed in pure water. Sn (tin) was laminated on the surface.

(Example 4)
Example 4 was the same as Example 1 except that there was no drying step between the first conductor removal step and the second conductor lamination step.
In Example 4, as in Example 2, the first conductor was removed between the first conductor removal step and the second conductor lamination step, and then the copper surface was dried while immersed in pure water. Without making it, Sn (tin) was laminated on the surface of copper.

(Example 5)
Example 5 is that the thickness of the insulating substrate is 13 μm, the point that the filled metal is changed from Cu to Ni, the point that the tip is made of Au (gold) with a thickness of 20 nm, and the first conductor removal Example 1 was the same as Example 1 except that there was no drying step between the step and the second conductor lamination step.
The nickel filling method was the same as in Example 3.
For the lamination of Au (gold) on nickel, specifically, a commercially available electroless Au (gold) plating solution (Flash Gold NC: manufactured by Okuno Seiyaku Kogyo Co., Ltd.) and a gold (I) sodium sulfite solution are constructed as specified. The bath was used and the liquid temperature was set to 70 ° C. for 10 seconds, followed by washing with pure water. At this time, the height of the second conductor (Au) laminated on the first conductor (copper) in the micropore was 20 nm.
In Example 5, after removing the first conductor between the first conductor removing step and the second conductor laminating step, the nickel surface was dried without being dried in the state of being immersed in pure water. Au (gold) was laminated on the surface.

(Example 6)
Example 6 is that the thickness of the insulating substrate is 9 μm, the point that the tip is Au (gold), the point that the removal of copper is other than melting, the first conductor removing step and the second conductor Example 1 was the same as Example 1 except that there was no drying step between the lamination steps.
In Example 6, the tip of Au (gold) was produced by the same method as in Example 5.
In Example 6, the surface after the flattening treatment was subjected to electroless plating of copper, and after forming a uniform film, an adhesive tape was attached to the surface, and then the tape was peeled off to be close to the surface in the through hole. Part of the copper was peeled off. OPC Copper AF (Okuno Pharmaceutical Co., Ltd.) was used for electroless copper plating.
In Example 6, the first conductor was removed between the first conductor removal step and the second conductor lamination step, and then the copper surface was dipped in pure water without being dried. Au (gold) was laminated on the surface.

(Example 7)
Example 7 was the same as Example 1 except that the insulating substrate had a thickness of 9 μm and the tip was Au (gold).
In Example 7, the tip of Au (gold) was produced by the same method as in Example 5.

(Example 8)
In Example 8, the thickness of the insulating base material is 9 μm, the point that the tip is Au (gold), and the drying step is between the first conductor removing step and the second conductor laminating step. The same as Example 1 except for the absence.
In Example 8, the tip of Au (gold) was produced by the same method as in Example 5.
In Example 8, the first conductor was removed between the first conductor removal step and the second conductor lamination step, and then the copper surface was dipped in pure water without being dried. Au (gold) was laminated on the surface.

Example 9
Example 9 has a point that the thickness of the insulating base material is 9 μm, a point where a protruding part is provided only on one side of the insulating base material, a point where the tip part is Au (gold), and a first conductor removing step Example 2 is the same as Example 1 except that there is no drying step between the first and second conductor lamination steps.
In Example 9, the tip of Au (gold) was produced in the same manner as in Example 5.
In Example 9, after removing the first conductor between the first conductor removing step and the second conductor laminating step, the copper surface was dipped in pure water without being dried. Au (gold) was laminated on the surface.

(Example 10)
Example 10 is that the thickness of the insulating base material is 17 μm, the point that the insulating base material is an anodic oxide film of titanium, the point that the tip is Au (gold), and the first conductor removing step Example 2 was the same as Example 1 except that there was no drying step between the second conductor lamination step.
In Example 10, the tip of Au (gold) was produced by the same method as in Example 5.
In Example 10, the first conductor was removed between the first conductor removing step and the second conductor laminating step, and then the copper surface was immersed in pure water without drying the copper surface. Au (gold) was laminated on the surface.
The titanium anodic oxide film was prepared by carrying out anodic oxidation for 45 minutes in a 0.01 M hydrochloric acid aqueous solution while maintaining a voltage of 20 V and a temperature of -2 ° C.

(Example 11)
In Example 11, the insulating base has a thickness of 14 μm, the base is Ni (nickel), the tip is Cu (copper), and the first conductor removing step and the second conductor. Example 1 was the same as Example 1 except that there was no drying step between the lamination steps.
The nickel filling method was the same as in Example 3. The method for forming copper was the same as in Example 1.
In Example 11, the first conductor was removed between the first conductor removing step and the second conductor laminating step, and then the nickel surface was immersed in pure water without drying the nickel surface. Copper was laminated on the surface.

(Comparative Example 1)
Comparative Example 1 is that the thickness of the insulating substrate is 10 μm, the point that the tip is Au (gold), the point that the smoothing step is not performed, the first conductor removing step and the second conductor Example 1 was the same as Example 1 except that there was no drying step between the lamination steps.
In Comparative Example 1, the tip of Au (gold) was produced in the same manner as in Example 5.
Moreover, in the comparative example 1, after removing a 1st conductor between a 1st conductor removal process and a 2nd conductor lamination process, without drying the copper surface in the state immersed in the pure water, Au (gold) was laminated on the copper surface.

(Comparative Example 2)
Comparative Example 2 was the same as Example 1 except that the insulating substrate had a thickness of 11 μm and no tip. Moreover, in the comparative example 2, the 1st conductor removal process and the 2nd conductor lamination process are not implemented. For this reason, there is no drying process.

(Comparative Example 3)
Comparative Example 3 is that the thickness of the insulating base material is 9 μm, there is no protrusion, the tip is Au (gold), and the first conductor removal step and the second conductor lamination step The same as Example 1 except that there was no drying step in between.
In Comparative Example 3, the tip of Au (gold) was produced in the same manner as in Example 5.
In Comparative Example 3, the first conductor was removed between the first conductor removal step and the second conductor lamination step, and then the anodization was performed without drying the copper surface in a state immersed in pure water. Gold was laminated on the copper exposed on the film surface.

As shown in Table 3, Examples 1 to 11 were superior in conduction resistance as compared to Comparative Examples 1 to 3.
In Comparative Example 1, the conduction resistance was poor. This is because in Comparative Example 1, since the surface smoothing process is not performed, the height of the conduction path tip varies and the number of conduction paths in contact with the electrode is reduced. Comparative Example 2 had no tip, had poor conduction resistance, and poor bondability.
In Comparative Example 3, the first conductor was not removed, and there was a high possibility that the tip end portion was in contact, and the adjacent conduction was bad.

DESCRIPTION OF SYMBOLS 10 Anisotropic conductive member 12 Insulating base material 12a Surface 12b Back surface 14 Through-hole 16 Conductor 16b, 16c Protrusion part 19 Resin layer 20 Base part 20c, 21c Side surface 20d End surface 21 Tip part 22 First conductor 22a, 22b Surface 23 Second conductor 24 Double-sided adhesive 25 Support member 26 Substrate 26a Surface 27 Barrier layer 28 Anodized film 29 Protective layer 30, 60, 61, 62, 63 Electronic device 32, 34, 36 Semiconductor element 37 Interposer 40 Semiconductor element 42 Sensor chip 44 Lens 50, 50a, 50b Terminal 50c End face 52 Semiconductor layer 52a, 54a, 56a Surface 54 Redistribution layer 56 Passivation layer 57 Wiring 58 Pad 66, 67, 71 Semiconductor element 68 Electrode 72 Hole 73 Optical waveguide 75, 76 Light emission Element Ds Stacking direction Dt Thickness direction H Height h Thickness of anisotropic conductive member Hs Height ht Thickness of insulating substrate Ld Emission light Lo Light R, Rs Equivalent diameter p Center distance x direction w Width between conductors

Claims (15)

An insulating substrate;
A plurality of conductors provided penetrating in the thickness direction of the insulating substrate;
The conductor includes a protruding portion protruding from at least one surface of the insulating substrate,
Each of the plurality of conductors has the same length of the protrusion,
The protruding portion includes a base portion on the insulating base material side, and a tip portion provided only on an end surface of the base portion on the opposite side of the insulating base material,
The tip portion is a metal-containing portion having a composition different from that of the base portion.
Anisotropic conductive member.   The anisotropic conductive member according to claim 1, wherein the metal constituting the tip portion has a smaller ionization tendency than the metal constituting the base portion.   3. The anisotropic conductive member according to claim 1, wherein each of the conductors has the protruding portion protruding from a front surface and a back surface of the insulating base.   The anisotropic conductive member according to claim 1, wherein an equivalent circle diameter of the base portion and an equivalent circle diameter of the tip portion are the same.   The anisotropic conductive member according to any one of claims 1 to 4, wherein the insulating substrate is made of a metal anodized film.   The anisotropic conductive member according to claim 5, wherein the insulating substrate is made of an anodic oxide film of aluminum or an anodic oxide film of titanium. A first conductor filling step of filling the through hole with a first conductor made of metal in an insulating base material having a plurality of through holes extending in the thickness direction;
A surface smoothing step of smoothing at least one surface of the insulating base material in which the first conductor is filled in the through hole;
A first conductor removing step of removing a part of the first conductor on the smoothed surface side and lowering the surface of the first conductor from the smoothed surface;
A second conductor laminating step of laminating a second conductor containing a metal having a composition different from that of the first conductor on the surface of the first conductor;
An insulating base material removing step of removing a part of the smoothed surface side of the insulating base material and causing the first conductor and the second conductor to protrude from the insulating base material is performed in this order. A method for producing an anisotropic conductive member. The first conductor removing step is a step of dissolving the first conductor;
The method for manufacturing an anisotropic conductive member according to claim 7, wherein the insulating base material removing step is a step of dissolving the insulating base material.   The anisotropic conductive member according to claim 7 or 8, wherein the insulating base material is in contact with a liquid during a period from the end of the first conductor removing step to the start of the second conductor laminating step. Production method.   The method for producing an anisotropic conductive member according to any one of 7 to 9, wherein the surface smoothing step smoothes both surfaces of the insulating base material in which the through hole is filled with the first conductor. .   The method for producing an anisotropic conductive member according to claim 7, wherein the metal constituting the second conductor has a smaller ionization tendency than the metal constituting the first conductor.   The method for manufacturing an anisotropic conductive member according to any one of claims 7 to 11, wherein the insulating substrate is made of a metal anodized film.   The method of manufacturing an anisotropic conductive member according to claim 12, wherein the insulating base material is made of an anodic oxide film of aluminum or an anodic oxide film of titanium.   A joined body comprising the anisotropic conductive member according to claim 1 and a member having a conductive region and joined to the anisotropic conductive member.   An electronic device comprising the joined body according to claim 14.