Method for manufacturing a metal-filled microstructured body

Abstract

The present invention provides a method for manufacturing a metal-filled fine structure with good conductivity. The method for manufacturing the metal-filled fine structure includes: a preparation step of preparing a structure having an insulating film and a plurality of conductors that penetrate the insulating film in the thickness direction and are arranged in an electrically insulated state from each other, the conductors protruding from at least one surface in the thickness direction of the insulating film, and the structure having a resin layer covering the surface of the insulating film from which the conductors protrude; a heating step of heating at least the resin layer in an atmosphere with an oxygen partial pressure of 10,000 Pa or less; and a removal step of removing the resin layer heated in the heating step from the insulating film. The resin layer contains a thermally peelable binder.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a metal-filled fine structure, which is as follows: a plurality of conductors penetrating in the thickness direction of an anodic oxide film and arranged in an electrically insulated state from each other protrude from at least one surface in the thickness direction of the anodic oxide film, and after heating, a resin layer covering the surface of the anodic oxide film from which the conductors protrude is removed. In particular, the present invention relates to a method for manufacturing a metal-filled fine structure in an atmosphere with an oxygen partial pressure of 10,000 Pa or less during heating of the resin layer. Background Art

[0002] Structures formed by filling conductive substances such as metals in a plurality of through holes provided in an insulating substrate are one of the fields attracting attention in nanotechnology in recent years, and are expected to be used as anisotropic conductive components, for example.

[0003] An anisotropic conductive component is inserted between an electronic component such as a semiconductor element and a circuit board, and an electrical connection between the electronic component and the circuit board is obtained only by applying pressure. Therefore, it is widely used as an electrical connection component for electronic components such as semiconductor elements and as a test connector during functional inspection.

[0004] In particular, the miniaturization of electronic components such as semiconductor elements is remarkable. In methods of directly connecting a wiring substrate such as conventional wire bonding, flip-chip bonding, and thermocompression bonding, since the stability of the electrical connection of electronic components sometimes cannot be sufficiently ensured, anisotropic conductive components have attracted much attention as electronic connection components.

[0005] As a method for manufacturing an anisotropic conductive component, for example, Patent Document 1 describes a method for manufacturing a metal-filled fine structure, which includes: an anodizing treatment step of forming an anodic oxide film by performing anodizing treatment on one surface of an aluminum substrate, and forming micropores existing in the thickness direction and a barrier layer existing at the bottom of the micropores on one surface of the aluminum substrate; after the anodizing treatment step, a barrier layer removal step of removing the barrier layer of the anodic oxide film using an alkaline aqueous solution containing a metal M1 having a higher hydrogen overvoltage than aluminum; after the barrier layer removal step, a metal filling step of performing electrolytic electroplating treatment to fill the inside of the micropores with a metal M2; and a substrate removal step of removing the aluminum substrate after the metal filling step to obtain a metal-filled fine structure. In Patent Document 1, after the metal filling step and before the substrate removal step, there is a resin layer forming step of providing a resin layer on the surface of the anodic oxide film on the side where the aluminum substrate is not provided.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent No. 6535098 Gazette Summary of the Invention

[0009] Technical Problem to be Solved by the Invention

[0010] In the above Patent Document 1, a resin layer is provided on the surface of the anodic oxidation film on the side where the aluminum substrate is not provided. The metal-filled microstructures are used, for example, for electrically connecting two semiconductor chips. In this case, it is necessary to peel off the above resin layer. As described above, when the metal-filled microstructures of Patent Document 1 are used for electrically connecting two semiconductor chips, the conductivity between the semiconductor chips is sometimes insufficient. A metal-filled microstructure with good conductivity is required.

[0011] An object of the present invention is to provide a method for manufacturing a metal-filled microstructure with good conductivity.

[0012] Means for Solving the Technical Problem

[0013] To achieve the above object, one aspect of the present invention provides a method for manufacturing a metal-filled microstructure, which includes: a preparation step of preparing a structure having an insulating film and a plurality of conductors penetrating the insulating film in the thickness direction and arranged in an electrically insulated state from each other, the conductors protruding from at least one surface in the thickness direction of the insulating film, and the structure having a resin layer covering the surface of the insulating film where the conductors protrude; a heating step of heating at least the resin layer in an atmosphere with an oxygen partial pressure of 10,000 Pa or less; and a removing step of removing the resin layer heated in the heating step from the insulating film, the resin layer containing a thermally peelable binder.

[0014] In the heating step, it is preferable that the oxygen partial pressure of the atmosphere is 1.0 Pa or less.

[0015] In the heating step, it is preferable that the partial pressure of the inert gas in the atmosphere is 85% or more of the total pressure of the atmosphere.

[0016] In the heating step, it is preferable that the partial pressure of the reducing gas in the atmosphere is 85% or more of the total pressure of the atmosphere.

[0017] In the heating step, it is preferable that the total pressure of the atmosphere is 5.0 Pa or less.

[0018] The conductor preferably contains base metal.

[0019] The plurality of conductors preferably have a cross-sectional area of 20 μm 2 or less in a cross-section perpendicular to the length direction of the conductor.

[0020] It is preferable that the temperature reached by the resin layer in the heating step is 150°C or less.

[0021] The conductor preferably protrudes from both sides in the thickness direction of the insulating film, and the resin layers are respectively provided on both sides in the thickness direction of the insulating film.

[0022] The insulating film is preferably an anodized film.

[0023] Advantages of the Invention

[0024] According to the present invention, a metal-filled micro-structured body with good conductivity can be obtained. Description of the Drawings

[0025] Figure 1 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0026] Figure 2 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0027] Figure 3 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0028] Figure 4 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0029] Figure 5 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0030] Figure 6 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0031] Figure 7 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0032] Figure 8 It is a schematic cross-sectional view of one step of an example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0033] Figure 9 It is a schematic cross-sectional view of one step of another example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0034] Figure 10 It is a schematic cross-sectional view of one step of another example of a method for manufacturing a metal-filled micro-structured body according to an embodiment of the present invention.

[0035] Figure 11 It is a schematic cross-sectional view of one process which is another example of the manufacturing method of the metal-filled fine structure showing an embodiment of the present invention.

[0036] Figure 12 It is a schematic perspective view of an example of the supply method of the anisotropic conductive member showing an embodiment of the present invention.

[0037] Figure 13 It is a schematic perspective view of an example of the supply method of the anisotropic conductive member showing an embodiment of the present invention.

[0038] Figure 14 It is a schematic view of an example of the joined body using the metal-filled fine structure showing an embodiment of the present invention. Detailed Description of the Invention

[0039] Hereinafter, based on the preferred embodiments shown in the drawings, the manufacturing method of the metal-filled fine structure of the present invention will be described in detail.

[0040] In addition, the drawings described below are illustrative drawings in the present invention, and the present invention is not limited to the drawings shown below.

[0041] In addition, "~" indicating a numerical range hereinafter means including the numerical values described on both sides. For example, ε a is the numerical value α b ~ the numerical value β c means that the range of ε a includes the numerical value α b and the numerical value β c In terms of mathematical notation, it is α b ≤ε a ≤β c .

[0042] Regarding temperature and time, unless otherwise specified, it includes the error range generally allowed in the corresponding technical field.

[0043] And, unless otherwise specified for parallelism, etc., it includes the error range generally allowed in the corresponding technical field.

[0044] [Metal-Filled Fine Structure]

[0045] Figures 1 to 8 It is a schematic cross-sectional view showing an example of the manufacturing method of the metal-filled fine structure showing an embodiment of the present invention in the order of processes.

[0046] As Figure 8As shown, the metal-filled micro-structure 10 has, for example: an insulating film 12 having electrical insulation properties; and a plurality of conductors 14 that penetrate the insulating film 12 in the thickness direction Dt and are arranged in a state of being electrically insulated from each other. The conductors 14 protrude from at least one surface in the thickness direction Dt of the insulating film 12. When the conductors 14 protrude from at least one surface in the thickness direction Dt of the insulating film 12, in the structure where they protrude from one side surface, it is preferably from the surface 12a or the back surface 12b. In the metal-filled micro-structure 10, the insulating film 12 is constituted by, for example, an anodic oxidation film 15.

[0047] The plurality of conductors 14 are arranged in the insulating film 12 in a state of being electrically insulated from each other. In this case, for example, the insulating film 12 has a plurality of fine holes 13 penetrating in the thickness direction Dt. The conductors 14 are provided in the plurality of fine holes 13. The conductors 14 protrude from the surface 12a in the thickness direction Dt of the insulating film 12.

[0048] The metal-filled micro-structure 10 has anisotropic conductivity in which the conductors 14 are arranged in a state of being electrically insulated from each other. The metal-filled micro-structure 10 has conductivity in the thickness direction Dt, but the conductivity in the direction parallel to the surface 12a of the insulating film 12 is sufficiently low.

[0049] The outer shape of the metal-filled micro-structure 10 is not particularly limited, and is, for example, a quadrilateral or a circle. The outer shape of the metal-filled micro-structure 10 can be formed into a shape corresponding to the use, ease of manufacture, etc.

[0050] [Manufacturing method of metal-filled micro-structure]

[0051] In an example of the manufacturing method of the metal-filled micro-structure, the case where the insulating film is constituted by an anodic oxidation film of aluminum is taken as an example for explanation. In order to form an anodic oxidation film of aluminum, an aluminum substrate is used. Therefore, in an example of the manufacturing method of the structure, first, as Figure 1 shown, an aluminum substrate 30 is prepared.

[0052] The size and thickness of the aluminum substrate 30 are appropriately determined according to the thickness of the insulating film 12 of the finally obtained metal-filled micro-structure 10 (refer to Figure 8 ), the device to be processed, etc. The aluminum substrate 30 is, for example, a plate-shaped material with a quadrilateral shape. In addition, it is not limited to the aluminum substrate, and a metal substrate capable of forming an electrically insulating insulating film 12 can also be used.

[0053] Next, an anodic oxidation treatment is performed on one surface 30a of the aluminum substrate 30 (refer to Figure 1 ). As a result, one surface 30a of the aluminum substrate 30 (refer to Figure 1 ) is anodized to form as Figure 2The insulating film 12, which is an anodic oxidation film 15, has a plurality of fine holes 13 extending in the thickness direction Dt of the aluminum substrate 30. A barrier layer 31 exists at the bottom of each fine hole 13. The process of performing the above anodic oxidation is called an anodic oxidation treatment process.

[0054] In the insulating film 12 having a plurality of fine holes 13, as described above, a barrier layer 31 exists at the bottom of each fine hole 13, but the Figure 2 shown barrier layer 31 will be removed. Thus, an insulating film 12 having a plurality of fine holes 13 without the barrier layer 31 is obtained (refer to Figure 3 ). In addition, the process of removing the above barrier layer 31 is called a barrier layer removal process.

[0055] In the barrier layer removal process, by using an alkaline aqueous solution containing ions of a metal M1 having a higher hydrogen overvoltage than aluminum, while removing the barrier layer 31 of the insulating film 12, a metal layer 35a composed of a metal (metal M1) is formed on the surface 32d (refer to Figure 3 ) of the bottom 32c of the fine hole 13 (refer to Figure 3 ) (refer to Figure 3 ). Thus, the aluminum substrate 30 exposed in the fine holes 13 is coated with the metal layer 35a. Thus, when filling the fine holes 13 with metal by electroplating, electroplating becomes easier, preventing insufficient filling of the metal into the fine holes and other problems, thereby suppressing defective formation of the conductor 14.

[0056] In addition, the alkaline aqueous solution containing ions of the above metal M1 may further contain a compound containing aluminum ions (such as sodium aluminate, aluminum hydroxide, alumina, etc.). When the content of the compound containing aluminum ions is converted in terms of the amount of aluminum ions, it is preferably 0.1 - 20 g / L, more preferably 0.3 - 12 g / L, and further preferably 0.5 - 6 g / L.

[0057] Next, electroplating is performed from the surface 12a of the insulating film 12 having a plurality of fine holes 13 extending in the thickness direction Dt. In this case, the metal layer 35a can be used as an electrode for electrolytic electroplating. When electroplating, metal 35b is used, and electroplating is started from the metal layer 35a formed on the surface 32d (refer to Figure 3 ) of the bottom 32c of the fine hole 13 (refer to Figure 3 ). Thus, as Figure 4 shown, the metal 35b constituting the conductor 14 is filled inside the fine holes 13 of the insulating film 12. By filling the inside of the fine holes 13 with the metal 35b, a conductive conductor 14 can be formed. In addition, the metal layer 35a and the metal 35b are collectively referred to as the filled metal 35.

[0058] The process of filling the fine holes 13 of the insulating film 12 with the metal 35b is called the metal filling process. As described above, the conductor 14 is not limited to being composed of a metal, and a conductive substance can be used. In the metal filling process, electrolytic plating is used, and the metal filling process will be described in detail later. In addition, the surface 12a of the insulating film 12 corresponds to one surface of the insulating film 12.

[0059] After the metal filling process, as Figure 5 shown, after the metal filling process, a part of the surface 12a on the side of the insulating film 12 where the aluminum substrate 30 is not provided is removed in the thickness direction Dt, and the metal 35 filled in the metal filling process is made to protrude from the surface 12a of the insulating film 12. That is, the conductor 14 is made to protrude from the surface 12a of the insulating film 12. Thus, the protruding portion 14a can be obtained. The process of making the conductor 14 protrude from the surface 12a of the insulating film 12 is called the surface metal protruding process.

[0060] After the surface metal protruding process, a resin layer 16 as Figure 6 described is formed on the surface 12a of the insulating film 12 of the conductor 14 where the protruding portion 14a is formed. Thus, the surface of the insulating film from which the conductor protrudes is covered with the resin layer to obtain the structure 18. The process of preparing the structure 18 is called the preparation process.

[0061] And, the process of forming the resin layer 16 that covers the surface of the insulating film 12 from which the conductor 14 protrudes is called the resin layer forming process. The resin layer 16 contains a thermally peelable binder.

[0062] After the resin layer forming process, as Figure 7 shown, the aluminum substrate 30 is removed from the structure 18. The process of removing the aluminum member 30 is called the substrate removing process.

[0063] Next, for the structure 18, at least the resin layer 16 is heated in an atmosphere with an oxygen partial pressure of 10000 Pa or less. The process of heating the resin layer 16 is called the heating process.

[0064] In the heating process, a heating device for semiconductor wafers used in the manufacture of semiconductor elements can be used.

[0065] The heating process is performed, for example, in a metal container used when heating a semiconductor wafer in a semiconductor manufacturing apparatus. The structure 18 after the substrate removal is placed in the container, and the oxygen partial pressure in the container is set to 10000 Pa or less.

[0066] In addition, the total pressure and partial pressure of the atmosphere in the heating process can be measured using a pressure gauge, for example. Thus, the above-mentioned oxygen partial pressure can be measured. Also, the partial pressure of the inert gas and the partial pressure of the reducing gas described later can be measured.

[0067] Regarding the oxygen partial pressure, for example, the oxygen partial pressure can be adjusted by degassing.

[0068] In addition, the heating process is not limited to an atmosphere with an oxygen partial pressure of 10,000 Pa or less. Preferably, the temperature reached by the resin layer in the heating process is 150°C or less. If the temperature reached by the resin layer in the heating process is 150°C or less, the conductivity becomes good.

[0069] Next, as Figure 8 shown, the resin layer 16 heated by the heating process is removed from the insulating film 12. Thus, the metal-filled micro-structure 10 is obtained.

[0070] In addition, the process of removing the resin layer 16 from the insulating film 12 is called the removal process. In the removal process, the method of removing the resin layer 16 is not particularly limited. For example, tools such as pliers are used for removal. In the removal process, tools such as pliers can be used to peel off the insulating film 12 from the resin layer 16. In addition, the atmosphere of the removal process does not need to be the same as that of the heating process. For example, it can be an atmospheric atmosphere.

[0071] Figures 9 to 11 It is a schematic cross-sectional view showing another example of the manufacturing method of the metal-filled micro-structure according to the embodiment of the present invention in the order of processes.

[0072] And, after Figure 7 shown substrate removal process, as Figure 9 shown, after the substrate removal process, a part of the back surface 12b of the insulating film 12 on the side where the aluminum substrate 30 is provided is removed in the thickness direction Dt, and the metal 35 filled in the metal filling process, that is, the conductor 14, protrudes from the back surface 12b of the insulating film 12. Thus, the protruding portion 14b can be obtained.

[0073] The above surface metal protruding process and back surface metal protruding process can be a method having two processes, or can be a method having one of the surface metal protruding process and the back surface metal protruding process. The surface metal protruding process and the back surface metal protruding process correspond to the "protruding process", and both the surface metal protruding process and the back surface metal protruding process are protruding processes.

[0074] As the structure 18, it can be a structure having protruding portions 14a and 14b that protrude from the surface 12a and the back surface 12b of the insulating film 12, that is, from both surfaces in the thickness direction Dt of the insulating film 12, as Figure 9 shown.

[0075] On Figure 9 the back surface 12b of the insulating film 12 shown, as Figure 10As shown, a resin layer 16 is formed, and resin layers 16 are provided on both sides in the thickness direction Dt of the anodic oxide film.

[0076] Next, the above-described heating process and the removal process of the resin layer 16 are performed on the structure 18 to obtain a metal-filled fine structure 10 having Figure 11 the protruding portions 14a and 14b shown.

[0077] In addition, in the above-described barrier layer removal process, an alkaline aqueous solution containing ions of a metal M1 having a higher hydrogen overvoltage than aluminum is used to remove the barrier layer. As a result, not only the barrier layer 31 is removed, but also a metal layer 35a of the metal M1 that is less likely to generate hydrogen than aluminum is formed on the aluminum substrate 30 exposed at the bottom of the pores 13. As a result, the in-plane uniformity of the metal filling becomes good. It is considered that hydrogen generation through the electroplating solution can be suppressed, and metal filling can be easily performed by electrolytic electroplating.

[0078] Furthermore, it has been found that by providing a holding process in the barrier layer removal process, the holding process is performed at a voltage (holding voltage) within a range of more than 95% and less than 105% of a voltage less than 30% of the voltage selected in the anodizing process for a total of 5 minutes or more, and by combining and applying an alkaline aqueous solution containing ions of the metal M1, the uniformity of metal filling during the electroplating process is significantly optimized. Therefore, it is preferable to have a holding process.

[0079] Although the detailed mechanism is not yet clear, the reason is considered as follows: In the barrier layer removal process, by using an alkaline aqueous solution containing metal M1 ions, a metal M1 layer is formed under the barrier layer, thereby suppressing damage to the interface between the aluminum substrate and the anodic oxide film and improving the dissolution uniformity of the barrier layer.

[0080] In addition, in the barrier layer removal process, a metal layer 35a composed of a metal (metal M1) is formed at the bottom of the pores 13, but it is not limited thereto, and only the barrier layer 31 is removed and the aluminum substrate 30 is exposed at the bottom of the pores 13. In a state where the aluminum substrate 30 is exposed, the aluminum substrate 30 can be used as an electrode for electrolytic electroplating.

[0081] 〔Anodic Oxide Film〕

[0082] In consideration of the reasons for forming pores having a desired average diameter as described above and easily forming a conductor, an anodic oxide film of aluminum is used for the anodic oxide film, for example. However, it is not limited to an anodic oxide film of aluminum, and an anodic oxide film of a valve metal can be used. Therefore, a valve metal is used for the metal substrate.

[0083] Here, as the valve metal, specifically, for example, it is the above-mentioned aluminum. In addition, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, etc. can be cited. Among them, from the viewpoint of good dimensional stability and low price, an anodic oxide film of aluminum is preferred. Therefore, it is preferable to use an aluminum substrate to manufacture the structure.

[0084] The thickness of the anodic oxide film is the same as the thickness ht of the above-mentioned insulating film 12.

[0085] 〔Metal substrate〕

[0086] The metal substrate is used for manufacturing the structure and is a substrate for forming an anodic oxide film. For example, as described above, a metal substrate capable of forming an anodic oxide film can be used, and a substrate made of the above-mentioned valve metal can be used. For example, as described above, from the reason of being easy to form an anodic oxide film as the anodic oxide film, an aluminum substrate is used as the metal substrate.

[0087] 〔Aluminum substrate〕

[0088] The aluminum substrate used for forming the insulating film 12 is not particularly limited. As specific examples, there can be cited: a pure aluminum plate; an alloy plate mainly composed of aluminum and containing a small amount of heterogeneous elements; a substrate obtained by vapor-depositing high-purity aluminum on low-purity aluminum (for example, recycled materials); a substrate obtained by coating high-purity aluminum on the surface of a silicon wafer, quartz, glass, etc. by methods such as vapor deposition and sputtering; a resin substrate laminated with aluminum, etc.

[0089] In the aluminum substrate, the surface on the side where the anodic oxide film is formed by anodic oxidation treatment preferably has an aluminum purity of 99.5 mass% or more, more preferably 99.9 mass% or more, and further preferably 99.99 mass% or more. If the aluminum purity is within the above range, the regularity of the micropore arrangement becomes sufficient.

[0090] The aluminum substrate is not particularly limited as long as it can form an anodic oxide film. For example, JIS (Japanese Industrial Standards) 1050 material is used.

[0091] The surface on the side of the aluminum substrate that is anodized is preferably pre-treated by heat treatment, degreasing treatment, and mirror finishing treatment.

[0092] Here, regarding the heat treatment, degreasing treatment, and mirror finishing treatment, the same treatments as those described in paragraphs

[0044] to

[0054] of Japanese Patent Laid-Open No. 2008-270158 can be implemented.

[0093] The mirror finishing treatment before anodic oxidation treatment is, for example, electrolytic polishing. In electrolytic polishing, for example, an electrolytic polishing solution containing phosphoric acid is used.

[0094] 〔Anodic oxidation treatment process〕

[0095] Anodic oxidation treatment can be carried out by known methods in the past. However, from the viewpoints of improving the orderliness of the micropore arrangement and ensuring the anisotropic conductivity of the structure, it is preferable to use the self-ordering method or the constant voltage treatment.

[0096] Here, regarding the self-ordering method and the constant voltage treatment of anodic oxidation treatment, the same treatments as those described in paragraphs

[0056] to

[0108] of Japanese Patent Laid-Open No. 2008-270158 and Figure 3 can be carried out.

[0097] 〔Retention process〕

[0098] The manufacturing method of the structure may have a retention process. The retention process is as follows: after the above anodic oxidation treatment process, at a voltage of 95% or more and 105% or less of the retention voltage selected from the range of 1 V or more and less than 30% of the voltage in the above anodic oxidation treatment process, retain for a total of 5 minutes or more. In other words, the retention process is as follows: after the above anodic oxidation treatment process, at a voltage of 95% or more and 105% or less of the retention voltage selected from the range of 1 V or more and less than 30% of the voltage in the above anodic oxidation treatment process, carry out electrolysis treatment for a total of 5 minutes or more.

[0099] Here, the "voltage in anodic oxidation treatment" is the voltage applied between aluminum and the counter electrode. For example, if the electrolysis time based on anodic oxidation treatment is 30 minutes, it refers to the average value of the voltage maintained during the 30 minutes.

[0100] From the viewpoint of controlling the thickness of the barrier layer to an appropriate thickness with respect to the depth of the pores, that is, the side wall thickness of the anodic oxidation film, the voltage in the retention process is preferably 5% or more and 25% or less of the voltage in anodic oxidation treatment, and more preferably 5% or more and 20% or less.

[0101] Moreover, from the reason of further improving the in-plane uniformity, the total retention time in the retention process is preferably 5 minutes or more and 20 minutes or less, more preferably 5 minutes or more and 15 minutes or less, and still more preferably 5 minutes or more and 10 minutes or less.

[0102] Also, the retention time in the retention process only needs to be 5 minutes or more in total, and preferably 5 minutes or more continuously.

[0103] In addition, the voltage in the holding step can be set to continuously or stepwise decrease from the voltage in the anodizing step to the voltage in the holding step. However, in consideration of further improving the in-plane uniformity, it is preferably set to a voltage of 95% or more and 105% or less of the above-mentioned holding voltage within 1 second after the end of the anodizing step.

[0104] The above-mentioned holding step can also be carried out continuously with the above-mentioned anodizing step, for example, by decreasing the electrolytic potential at the end of the above-mentioned anodizing step.

[0105] Regarding the conditions other than the electrolytic potential, the above-mentioned holding step can adopt the same electrolyte solution and treatment conditions as those of the above-mentioned conventionally known anodizing treatment.

[0106] In particular, in the case of continuously carrying out the holding step and the anodizing step, it is preferable to carry out the treatment using the same electrolyte solution.

[0107] In the anodic oxide film having a plurality of micropores, as described above, a barrier layer (not shown) exists at the bottom of the micropores. There is a barrier layer removal step for removing this barrier layer.

[0108] 〔Barrier layer removal step〕

[0109] The barrier layer removal step is, for example, a step of removing the barrier layer of the anodic oxide film using an alkaline aqueous solution containing metal M1 ions having a higher hydrogen overvoltage than aluminum.

[0110] By the above-mentioned barrier layer removal step, the barrier layer is removed, and a conductor layer composed of metal M1 is formed at the bottom of the micropores.

[0111] Here, the hydrogen overvoltage is the voltage required to generate hydrogen. For example, the hydrogen overvoltage of aluminum (Al) is -1.66V (Journal of the Chemical Society of Japan, 1982, (8), p1305 - 1313). In addition, examples of metal M1 having a higher hydrogen overvoltage than aluminum and their hydrogen overvoltage values are shown below.

[0112] <Metal M1 and hydrogen (1N H2SO4) overvoltage>

[0113] · Platinum (Pt): 0.00V

[0114] · Gold (Au): 0.02V

[0115] · Silver (Ag): 0.08V

[0116] · Nickel (Ni): 0.21V

[0117] · Copper (Cu): 0.23V

[0118] · Tin (Sn): 0.53V

[0119] · Zinc (Zn): 0.70V

[0120] In the present invention, considering the reason that it causes a substitution reaction with the metal M2 filled in the subsequent anodization treatment step and has little influence on the electrical properties of the metal filled inside the micropores, the metal M1 used in the above barrier layer removal step is preferably a metal with a higher ionization tendency than the metal M2 used in the subsequent metal filling step.

[0121] Specifically, when copper (Cu) is used as the metal M2 in the subsequent metal filling step, as the metal M1 used in the above barrier layer removal step, for example, Zn, Fe, Ni, Sn, etc. can be cited. Among them, it is preferable to use Zn or Ni, and more preferably to use Zn.

[0122] Also, when nickel (Ni) is used as the metal M2 in the subsequent metal filling step, as the metal M1 used in the above barrier layer removal step, for example, Zn, Fe, etc. can be cited. Among them, it is preferable to use Zn.

[0123] The method of removing the barrier layer using an alkaline aqueous solution containing such a metal M1 is not particularly limited. For example, a method similar to the conventionally known chemical etching treatment can be cited.

[0124] <Chemical etching treatment>

[0125] Regarding the removal of the barrier layer by chemical etching treatment, for example, after immersing the structure after the above anodization treatment step in an alkaline aqueous solution and filling the alkaline aqueous solution inside the micropores, by bringing the side surface of the opening of the micropores of the anodic oxide film into contact with a pH buffer solution, etc., the barrier layer can be selectively dissolved only.

[0126] Here, as the alkaline aqueous solution containing the above metal M1, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. And the concentration of the alkaline aqueous solution is preferably 0.1 to 5% by 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.

[0127] Specifically, for example, a phosphoric acid aqueous solution of 50 g / L and 40 °C, a sodium hydroxide aqueous solution of 0.5 g / L and 30 °C, a potassium hydroxide aqueous solution of 0.5 g / L and 30 °C, etc. can be preferably used.

[0128] In addition, as the pH buffer solution, a buffer solution corresponding to the above alkaline aqueous solution can be appropriately used.

[0129] Moreover, the impregnation 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 particularly preferably 10 to 90 minutes. Among them, it is preferably 10 to 60 minutes, and more preferably 15 to 60 minutes.

[0130] The micropores 13 can also be formed by expanding the diameter of the micropores and removing the barrier layer. In this case, a pore-expanding treatment can be used for expanding the diameter of the micropores. The pore-expanding treatment is a treatment for dissolving the anodic oxide film and expanding the pore diameter of the micropores by immersing the anodic oxide film in an acidic aqueous solution or an alkaline aqueous solution. In the pore-expanding treatment, inorganic acids such as sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid, or aqueous solutions of mixtures thereof, or aqueous solutions of sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. can be used.

[0131] In addition, the barrier layer at the bottom of the micropores can also be removed in the pore-expanding treatment. By using an aqueous sodium hydroxide solution in the pore-expanding treatment, the micropores are expanded in diameter and the barrier layer is removed.

[0132] 〔Metal filling process〕

[0133] <Metal used in the metal filling process>

[0134] In the metal filling process, the metal filled as a conductor inside the above-mentioned micropores 13 to form a conductor and the metal constituting the metal layer preferably have a resistivity of 10 3 Ω·cm or less. As specific examples of the above-mentioned metal, gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni), zinc (Zn), etc. can be preferably exemplified.

[0135] In addition, as the conductor, from the viewpoints of conductivity and formation based on the electroplating method, copper (Cu), gold (Au), aluminum (Al), nickel (Ni) are preferred, copper (Cu) and gold (Au) are more preferred, and copper (Cu) is still more preferred.

[0136] <Electroplating method>

[0137] As the electroplating method for filling metal inside the micropores, for example, an electrolytic electroplating method or a non-electrolytic electroplating method can be used.

[0138] Here, in the conventionally well-known electrolytic electroplating method used in coloring and the like, it is difficult to selectively deposit (grow) metal in the pores with a high aspect ratio. It is considered that the reason is that even if the deposited metal is consumed in the pores and electrolysis is carried out for a specified time or more, the coating layer will not grow.

[0139] Therefore, in the case of filling metal by the electrolytic electroplating method, a pause time needs to be set during pulse electrolysis or constant potential electrolysis. The pause time needs to be 10 seconds or more, and is preferably 30 to 60 seconds.

[0140] Further, in order to promote the agitation of the electrolytic solution, it is also desirable to apply ultrasonic waves.

[0141] In addition, the electrolytic voltage is usually 20 V or less, preferably 10 V or less. However, it is preferable to previously measure the deposition potential of the target metal in the electrolytic solution to be used and perform constant potential electrolysis within +1 V of this potential. Further, when performing constant potential electrolysis, it is preferable to be able to use cyclic voltammetry simultaneously, and it is possible to use potentiostat devices such as those of Solartron Corporation, BAS Inc., HOKUTODENKO CORP., and IVIUM Corporation.

[0142] (Electroplating solution)

[0143] As the electroplating solution, conventionally known electroplating solutions can be used.

[0144] Specifically, in the case of depositing copper, an aqueous solution of copper sulfate is usually used. However, the concentration of copper sulfate is preferably 1 to 300 g / L, more preferably 100 to 200 g / L. Further, if hydrochloric acid is added to the electrolytic solution, deposition can be promoted. In this case, the hydrochloric acid concentration is preferably 10 to 20 g / L.

[0145] Further, in the case of depositing gold, it is preferable to use a sulfuric acid solution of chloroauric acid and perform electroplating by alternating current electrolysis.

[0146] The electroplating solution preferably contains a surfactant.

[0147] As the surfactant, known substances can be used. It is also possible to directly use sodium dodecyl sulfate, which has been conventionally known as a surfactant added to electroplating solutions. Substances in which the hydrophilic part is ionic (cationic / anionic / amphoteric) or non-ionic (non-ionic) can all be used. However, from the viewpoint of preventing the generation of bubbles on the surface of the object to be electroplated, cationic surfactants are preferred. It is desirable that the concentration of the surfactant in the electroplating solution composition is 1 mass% or less.

[0148] In addition, in the non-electrolytic electroplating method, since it takes a long time to completely fill the pores composed of high aspect ratio fine pores with metal, it is desirable to fill the fine pores with metal using the electrolytic electroplating method.

[0149] 〔Substrate removal step〕

[0150] The substrate removal step is a step of removing the above-mentioned aluminum substrate after the metal filling step. The method for removing the aluminum substrate is not particularly limited, and for example, a method of removing by dissolution can be preferably cited.

[0151] <Dissolution of aluminum substrate>

[0152] In the dissolution of the above-mentioned aluminum substrate, it is preferable to use a treatment liquid that does not easily dissolve the anodic oxidation film and easily dissolves aluminum.

[0153] The dissolution rate of this treatment liquid for aluminum is preferably 1 μm / minute or more, more preferably 3 μm / minute or more, and further preferably 5 μm / minute or more. Similarly, the dissolution rate for the anodic oxidation film is preferably 0.1 nm / minute or less, more preferably 0.05 nm / minute or less, and further preferably 0.01 nm / minute or less.

[0154] Specifically, it is preferably a treatment liquid containing at least one metal compound with a lower ionization tendency than aluminum and having a pH (hydrogen ion index) of 4 or less or 8 or more, more preferably a pH of 3 or less or 9 or more, and further preferably 2 or less or 10 or more.

[0155] As the treatment liquid for dissolving aluminum, an acid or alkaline aqueous solution is used as a matrix. For example, it is preferably a substance admixed with compounds of manganese, zinc, chromium, iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper, mercury, silver, palladium, platinum, gold (such as chloroplatinic acid), fluorides of these, chlorides of these, etc.

[0156] Among them, an acidic aqueous solution matrix is preferred, and a mixed chloride is preferred.

[0157] In particular, from the perspective of the treatment range, a treatment liquid (hydrochloric acid / hydrochloric mercury) in which mercury chloride is mixed in a hydrochloric acid aqueous solution and a treatment liquid (hydrochloric acid / copper chloride) in which copper chloride is mixed in a hydrochloric acid aqueous solution are preferred.

[0158] In addition, the composition of the treatment liquid for dissolving aluminum is not particularly limited. For example, bromine / methanol mixtures, bromine / ethanol mixtures, and aqua regia can be used.

[0159] Moreover, the acid or base concentration of the treatment liquid for dissolving aluminum is preferably 0.01 - 10 mol / L, more preferably 0.05 - 5 mol / L.

[0160] Furthermore, the treatment temperature when using the treatment liquid for dissolving aluminum is preferably -10°C to 80°C, and preferably 0°C to 60°C.

[0161] And the dissolution of the above-mentioned aluminum substrate is carried out by bringing the aluminum substrate after the above-mentioned electroplating process into contact with the above-mentioned treatment liquid. The contact method is not particularly limited. For example, the dipping method and the spraying method can be cited. Among them, the dipping method is preferred. As the contact time at this time, it is preferably 10 seconds to 5 hours, more preferably 1 minute to 3 hours.

[0162] In addition, the insulating film 12 can be provided with a support, for example. Preferably, the support has the same shape as the insulating film 12. The operability is improved by installing the support.

[0163] 〔Projection process〕

[0164] When removing a part of the above-mentioned insulating film 12, for example, an acidic aqueous solution or a basic aqueous solution that does not dissolve the metal constituting the conductor 14 but dissolves the insulating film 12, i.e., alumina (Al2O3), can be used. By bringing the above-mentioned acidic aqueous solution or basic aqueous solution into contact with the insulating film 12 having the fine pores 13 filled with metal, a part of the insulating film 12 is removed. The method of bringing the above-mentioned acidic aqueous solution or basic aqueous solution into contact with the insulating film 12 is not particularly limited. For example, dipping method and spraying method can be cited. Among them, the dipping method is preferred.

[0165] When using an acidic aqueous solution, it is preferably an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid or an aqueous solution of a mixture of these. Among them, from the aspect of excellent safety, an aqueous solution not containing chromic acid is preferred. The concentration of the acidic aqueous solution is preferably 1 to 10% by mass. The temperature of the acidic aqueous solution is preferably 25 to 60 °C.

[0166] And when using a basic aqueous solution, it is preferably at least one basic aqueous solution selected from the group including sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the basic aqueous solution is preferably 0.1 to 5% by mass. The temperature of the basic aqueous solution is preferably 20 to 35 °C.

[0167] Specifically, for example, it is preferably to use a phosphoric acid aqueous solution of 50 g / L and 40 °C, a sodium hydroxide aqueous solution of 0.5 g / L and 30 °C, or a potassium hydroxide aqueous solution of 0.5 g / L and 30 °C.

[0168] Regarding the dipping time of the acidic aqueous solution or the basic aqueous solution, it is preferably 8 to 120 minutes, more preferably 10 to 90 minutes, and further preferably 15 to 60 minutes. Here, the dipping time refers to the total of each dipping time in the case of repeating short-time dipping treatments. In addition, a cleaning treatment can be performed between each dipping treatment.

[0169] And the degree to which the metal 35, i.e., the conductor 14, protrudes from the surface 12a or the back surface 12b of the insulating film 12 is preferably such that the conductor 14 protrudes 10 nm to 1000 nm from the surface 12a or the back surface 12b of the insulating film 12, more preferably 50 nm to 500 nm. That is, the protruding amount of the protruding portion 14a from the surface 12a of the insulating film 12 and the protruding amount of the protruding portion 14b from the conductor 14 of the back surface 12b of the insulating film 12 are each preferably 10 nm to 1000 nm, more preferably 50 nm to 500 nm.

[0170] The height of the protrusions 14a and 14b of the conductor 14 means the average value of the heights of the protrusions of the conductor measured at 10 points by observing the cross-section of the metal-filled microstructural body 10 with an electrolytic emission scanning electron microscope at a magnification of 20,000 times.

[0171] When strictly controlling the height of the protrusions of the conductor 14, it is preferable to fill the inside of the fine holes 13 with a conductive material such as metal, then process the ends of the insulating film 12 and the conductive material such as metal into the same planar shape, and then selectively remove the anodic oxidation film.

[0172] Moreover, after filling the above-mentioned metal or after the protrusion process, a heat treatment can be carried out for the purpose of reducing the strain in the conductor 14 generated by the filled metal.

[0173] From the viewpoint of suppressing metal oxidation, it is preferable that the heat treatment is carried out in a reducing atmosphere. Specifically, it is preferably carried out under the condition that the oxygen concentration is 20 Pa or less, and more preferably carried out under vacuum. Here, vacuum means the state of a space in which at least one of the gas density and the air pressure is lower than that of the atmosphere.

[0174] Moreover, for the purpose of correction, it is preferable to carry out the heat treatment while applying stress to the insulating film 12.

[0175] 〔Resin layer forming process〕

[0176] As described above, it is a process of forming a resin layer covering the surface of the insulating film protruding from the conductor. The resin layer is provided to protect the conductor and further improve the transportability.

[0177] The resin layer forming process is a process carried out after the above-mentioned metal filling process, after the surface metal protrusion process, and before the substrate removal process.

[0178] As described above, the resin layer contains a thermally peelable binder. From the viewpoints of transportability and ease of use as an anisotropic conductive component, it is more preferable that the resin layer becomes less adhesive and becomes a film with an adhesive layer that can be peeled by heat treatment.

[0179] The method of pasting the above-mentioned film with an adhesive layer is not particularly limited, and a conventionally known surface protection tape pasting device or laminator can be used for pasting.

[0180] As a film with an adhesive layer that becomes less adhesive and can be peeled by the above-mentioned heat treatment, a thermally peelable resin layer can be cited.

[0181] Here, the thermally peelable resin layer has adhesiveness at room temperature and can be easily peeled only by heating. Therefore, foaming microcapsules and the like are mainly used.

[0182] And, as the adhesive that constitutes the adhesive layer, specifically, for example, rubber adhesives, acrylic adhesives, vinyl alkyl ether adhesives, polysiloxane adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, styrene-diene block copolymer adhesives, etc. can be cited.

[0183] As commercially available products of the thermally peelable resin layer, for example, WS5130C02, WS5130C10 and other Intellimer [registered trademark] tapes (manufactured by NITTA Corporation); Somatac [registered trademark] TE series (manufactured by SOMAR Corporation); No. 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. 3193MS and other Riva Alpha [registered trademark] series (manufactured by NITTO DENKO CORPORATION.) etc.

[0184] 〔Heating process〕

[0185] The heating process is a process for making it easy to remove the resin layer in order to remove the resin layer. And, when simply heating the resin layer, sometimes the resistance increases due to the oxidation of the metal type constituting the conductor. Therefore, when using a metal-filled fine structure for the anisotropic conductive component and electrically connecting the semiconductor chip, sometimes the conductivity decreases. However, by carrying out the heating process in an atmosphere with an oxygen partial pressure of 10,000 Pa or less, the increase in resistance is suppressed, and when electrically connecting the semiconductor chip, the conductivity becomes good.

[0186] In the heating process, the oxygen partial pressure of the atmosphere is 10,000 Pa or less, preferably 1.0 Pa or less. When the oxygen partial pressure is 10,000 Pa or less, the oxidation of the conductor is suppressed, and the smaller the oxygen partial pressure, the oxidation is suppressed regardless of the metal type of the conductor, so it is preferred.

[0187] The heating process can be set to the atmosphere described below. For example, when the total pressure of the atmosphere is set to 100%, the partial pressure of the inert gas in the atmosphere is preferably 85% or more of the total pressure of the atmosphere. When the partial pressure of the inert gas in the atmosphere is 85% or more of the total pressure, the oxygen partial pressure can be relatively reduced, and the oxidation of the conductor can also be inhibited.

[0188] In addition, regarding the partial pressure of the inert gas, for example, the partial pressure of the inert gas can be adjusted by adjusting the supply amount of the inert gas into the container in which the heating process is carried out.

[0189] Moreover, in the heating process, for example, when the total pressure of the atmosphere is set to 100%, the partial pressure of the reducing gas in the atmosphere is preferably 85% or more of the total pressure of the atmosphere. When the partial pressure of the reducing gas in the atmosphere is 85% or more of the total pressure, the oxygen partial pressure can be relatively reduced, and the oxidation of the conductor can also be inhibited. In addition, the reducing gas is preferably a gas with little reaction with the conductor.

[0190] In addition, regarding the partial pressure of the reducing gas, for example, the partial pressure of the reducing gas can be adjusted by adjusting the supply amount of the reducing gas into the container in which the heating process is carried out.

[0191] <Inert gas>

[0192] The inert gas is not particularly limited. For example, it is a noble gas such as helium, neon, and argon, or nitrogen, etc. As the inert gas, the above various gases can be used alone, or at least two gases can be mixed.

[0193] <Reducing gas>

[0194] The reducing gas is not particularly limited. For example, it is hydrogen, carbon monoxide, or hydrocarbon gases such as CH4, C3H8, or C4H 1o etc. As the reducing gas, the above various gases can be used alone, or at least two gases can be mixed.

[0195] Moreover, the total pressure of the atmosphere in the heating process is preferably 5.0 Pa or less. When the total pressure of the atmosphere in the heating process is 5.0 Pa or less, the oxygen partial pressure of the atmosphere becomes small, and the oxidation of the conductor can be inhibited, so it is preferred. The total pressure of the atmosphere can be set to 5.0 Pa or less, for example, by using a vacuum pump to reduce the pressure in the container.

[0196] <Atmosphere of the heating process>

[0197] The atmosphere of the heating process can reduce the oxygen partial pressure by degassing as described above, can replace the atmosphere with an inert gas or a reducing gas, or can replace the atmosphere with an inert gas and a reducing gas.

[0198] Regarding the heating conditions in the heating process, the temperature is preferably 80 to 350 °C, more preferably 90 to 250 °C, and most preferably 100 to 200 °C. In addition, the temperature reached by the resin layer in the heating process is preferably 150 °C or lower. In the heating process, if the temperature is lower than the above temperature range, it becomes difficult to peel off the resin layer. On the other hand, if the temperature is high, oxidation of the filled metal occurs, that is, oxidation of the conductor occurs, and it becomes the cause of defects such as stripes or cracks in the structure.

[0199] 〔Removal process〕

[0200] After the heating process, it is a process for removing the resin layer. Regarding the removal process, there is no particular limitation as long as the resin layer can be removed.

[0201] Moreover, regarding the removal process, the atmosphere does not need to be the same as that of the heating process. After heating the resin layer, for example, it can be removed from the container used in the heating process and carried out in the atmospheric atmosphere.

[0202] <Other manufacturing processes>

[0203] An anodizing process can be performed on a part of the surface of the aluminum substrate using a mask layer of a desired shape.

[0204] 〔Winding process〕

[0205] In addition, after the substrate is removed Figure 7 The structure 18 shown is a manner of being wound into a roll and supplied to the core 21 as shown Figure 12 For example, when the metal-filled micro-structure 10 is used as an anisotropic conductive component, the resin layer 16 is removed by performing the above heating process and the removal process of the resin layer 16 (refer to Figure 13 ). Thus, for example, the metal-filled micro-structure 10 can be used as an anisotropic conductive component.

[0206] Considering the reason for further improving the transportability of the metal-filled micro-structure 10, it is preferable to have a winding process after any of the above resin layer forming processes. In this winding process, the metal-filled micro-structure 10 is wound into a roll in a state having the above resin layer 16.

[0207] Here, the winding method in the above winding process is not particularly limited. For example, a method of winding around a core 21 having a specific diameter and a specific width can be cited (refer to Figure 12 ).

[0208] Moreover, from the viewpoint of the ease of winding in the above winding process, the resin layer 16 is removed (refer to Figure 13) The average thickness of the metal-filled micro-structure 10 is preferably 30 μm or less, more preferably 5 to 20 μm. In addition, the metal-filled micro-structure 10 from which the resin layer has been removed is cut in the thickness direction using FIB (Focused Ion Beam), and a surface photograph (magnification: 50,000 times) of the cross-section is taken using a field emission scanning electron microscope (FE-SEM), and the average thickness is calculated by methods such as taking the average of 10 measurements.

[0209] 〔Other processing steps〕

[0210] In addition to the above-mentioned steps, the manufacturing method of the present invention may further include a polishing step, a surface smoothing step, a protective film formation treatment, and a water washing treatment described in paragraphs

[0049] to

[0057] of International Publication No. 2015 / 029881.

[0211] Furthermore, from the viewpoints of manufacturing processability and using the metal-filled micro-structure 10 as an anisotropic conductive component, various procedures and forms as described below can be applied.

[0212] <Example of procedure using a temporary adhesive>

[0213] In the present invention, after the above-mentioned substrate removal step, there may be a step of fixing the metal-filled micro-structure to a silicon wafer using a temporary adhesive (Temporary Bonding Materials) and thinning it by polishing.

[0214] Next, after the thinning step and after thoroughly cleaning the surface, the above-mentioned surface metal protrusion step can be performed.

[0215] Next, after applying a temporary adhesive having a stronger adhesive force than the previous temporary adhesive on the surface with the protruded metal and fixing it to a silicon wafer, the silicon wafer bonded with the previous temporary adhesive is peeled off, and the above-mentioned back surface metal protrusion step can be performed on the side surface of the peeled metal-filled micro-structure.

[0216] <Example of procedure using WAX>

[0217] In the present invention, after the above-mentioned substrate removal step, there may be a step of fixing the metal-filled micro-structure to a silicon wafer using paraffin and thinning it by polishing.

[0218] Next, after the thinning step and after thoroughly cleaning the surface, the above-mentioned surface metal protrusion step can be performed.

[0219] Next, after applying a temporary adhesive on the surface where the metal protrudes and fixing it to the silicon wafer, the paraffin wax is dissolved by heating and the silicon wafer is peeled off, enabling the above-described backside metal protrusion process to be performed on the side surface of the peeled metal-filled micro-structure.

[0220] In addition, although solid paraffin wax can be used, if SKYCOAT (manufactured by NIKKA SEIKO CO., LTD.) or the like is used, improvement in coating thickness uniformity can be achieved.

[0221] <Example of procedure after substrate removal processing>

[0222] In the present invention, the following procedure may be included: after the above-described metal filling process and before the above-described substrate removal process, the aluminum substrate is fixed to a rigid substrate (such as a silicon wafer, a glass substrate, etc.) using a temporary adhesive, paraffin wax, or a functional adsorption film, and then thinned by grinding the surface of the side of the anodic oxidation film where the aluminum substrate is not provided.

[0223] Next, after the thinning process and after thoroughly cleaning the surface, the above-described surface metal protrusion process can be performed.

[0224] Next, after applying an insulating material, i.e., a resin material (such as an epoxy resin, a polyimide resin, etc.) on the surface where the metal protrudes, a rigid substrate can be pasted on its surface by the same method as above. By pasting with a resin material, a material having a bonding force greater than that of a temporary adhesive or the like can be selected. After pasting with the resin material, the initially pasted rigid substrate is peeled off, and the above-described substrate removal process, grinding process, and backside metal protrusion treatment process are sequentially performed.

[0225] In addition, as the functional adsorption film, Q-chuck (registered trademark) (manufactured by MARUISHI SANGYO CO., LTD.) or the like can be used.

[0226] In the present invention, it is preferable to provide the metal-filled micro-structure as a product in a state where it is pasted to a rigid substrate (such as a silicon wafer, a glass substrate, etc.) through a peelable layer.

[0227] In this supply method, when the metal-filled micro-structure is used as a bonding component, the surface of the metal-filled micro-structure is temporarily bonded to the device surface. After peeling off the rigid substrate, the device to be connected is set at an appropriate position and heated and pressed, whereby the upper and lower devices can be bonded through the metal-filled micro-structure.

[0228] Furthermore, the peelable layer can be a thermal peelable layer or a photo peelable layer used in combination with a glass substrate.

[0229] Further, in the manufacturing method of the present invention, each of the above-described processes can be carried out for each single piece, or a roll of aluminum can be used as the original roll and processed continuously in a coil form.

[0230] Moreover, in the case of continuous processing, it is preferable to provide appropriate cleaning processes and drying processes between each process.

[0231] By the manufacturing method of the present invention having such respective processing steps, a metal-filled fine structure in which a metal is filled inside through-holes is obtained. The above-described through-holes are derived from micropores provided in an insulating substrate composed of an anodic oxide film of an aluminum substrate.

[0232] Specifically, by the manufacturing method of the present invention, an anisotropic conductive component described in, for example, Japanese Patent Application Laid-Open No. 2008-270158 can be obtained, that is, an anisotropic conductive component provided in the following state: in an insulating substrate (anodic oxide film of an aluminum substrate having micropores), a plurality of conduction paths composed of conductive components (metals) penetrate the insulating substrate in the thickness direction in a state of being insulated from each other, and one end of each of the above-described conduction paths is exposed on one surface of the insulating substrate, and the other end of each of the above-described conduction paths is exposed on the other surface of the insulating substrate.

[0233] Hereinafter, the configuration of the metal-filled fine structure will be described in more detail.

[0234] 〔Insulating film〕

[0235] The insulating film 12 is composed of a conductor and keeps a plurality of conductors 14 in a state of being electrically insulated from each other. The insulating film has electrical insulation. Further, the insulating film 12 has a plurality of fine holes 13 formed by the conductors 14.

[0236] The insulating film is composed of an inorganic material, for example. The insulating film can use a material having a resistivity of about 10 14 Ω·cm.

[0237] In addition, "composed of an inorganic material" is a regulation for differentiating from a polymer material, and is not limited to a regulation of an insulating substrate composed only of an inorganic material, but is a regulation in which an inorganic material is a main component (50 mass% or more). As described above, the insulating film is composed of an anodic oxide film, for example.

[0238] Moreover, the insulating film can also be composed of, for example, metal oxides, metal nitrides, glass, ceramics such as silicon carbide and silicon nitride, carbon substrates such as diamond-like carbon, polyimide, and these composite materials. As the insulating film, in addition to the above, for example, an inorganic material containing 50 mass% or more of a ceramic material or a carbon material can be formed on an organic raw material having through-holes.

[0239] The length in the thickness direction Dt of the insulating film 12, i.e., the thickness of the insulating film 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. If the thickness of the insulating film 12 is within this range, the workability of the insulating film 12 becomes good.

[0240] From the viewpoint of winding ease, the thickness ht of the insulating film 12 is preferably 30 μm or less, more preferably 5 to 20 μm.

[0241] In addition, the thickness of the anodic oxidation film is a value calculated as the average of 10 measurements by cutting the anodic oxidation film in the thickness direction Dt with a focused ion beam (FIB) and photographing the cross section thereof with a field emission scanning electron microscope (FE-SEM) at a magnification of 50,000 times.

[0242] The interval between the respective conductors 14 in the insulating film 12 is preferably 5 nm to 800 nm, more preferably 10 nm to 200 nm, and still more preferably 20 nm to 60 nm. If the interval between the respective conductors 14 in the insulating film 12 is within the above range, the insulating film 12 sufficiently functions as a partition for electrical insulation of the conductors 14.

[0243] Here, the interval between the respective conductors refers to the width between adjacent conductors, and is the average value of the widths between adjacent conductors measured at 10 points by observing the cross section of the metal-filled microstructured body 10 with a field emission scanning electron microscope at a magnification of 200,000 times.

[0244] <Average diameter of pores>

[0245] The average diameter of the pores is preferably 1 μm or less, more preferably 5 to 500 nm, still more preferably 20 to 400 nm, even more preferably 40 to 200 nm, and most preferably 50 to 100 nm. If the average diameter d of the pores 13 is 1 μm or less and within the above range, conductors 14 having the above average diameter can be obtained.

[0246] The average diameter of the pores 13 is obtained by photographing the surface of the insulating film 12 from directly above with a scanning electron microscope at a magnification of 100 to 10,000 times to obtain a photographic image. In the photographic image, at least 20 pores connected in a ring shape around are extracted, their diameters are measured and set as the opening diameters, and the average value of these opening diameters is calculated as the average diameter of the pores.

[0247] In addition, the magnification can appropriately select a magnification within the above range to obtain a photographic image capable of extracting more than 20 fine holes. And the opening diameter measures the maximum value of the distance between the ends of the fine hole portion. That is, since the shape of the opening portion of the fine hole is not limited to a substantially circular shape, when the shape of the opening portion is non-circular, the maximum value of the distance between the ends of the fine hole portion is set as the opening diameter. Thus, for example, in the case of a fine hole having a shape in which two or more fine holes are integrated, it is also regarded as one fine hole, and the maximum value of the distance between the ends of the fine hole portion is set as the opening diameter.

[0248] 〔Conductor〕

[0249] As described above, a plurality of conductors 14 are provided in the anodic oxide film in a state of being electrically insulated from each other.

[0250] The plurality of conductors 14 have conductivity. The conductor is made of a conductive material. The conductive material is not particularly limited, and metals can be cited. As specific examples of metals, gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), and nickel (Ni) are preferably exemplified. From the viewpoint of conductivity, copper, gold, aluminum, and nickel are preferred, copper and gold are more preferred, and copper is most preferred. Among metals, although copper is a base metal, it can also be a base metal. Although base metals are easily oxidized in air, in the manufacturing method of the metal-filled microstructures, even if the conductor is made of a base metal, a metal-filled microstructure with good conductivity can be obtained.

[0251] In addition to metals, oxide conductive materials can be cited. As the oxide conductive material, for example, indium-doped tin oxide (ITO) is exemplified. However, metals are superior to oxide conductors in terms of ductility and are easily deformed, and are also easily deformed even under compression during bonding, so it is preferably made of a metal.

[0252] And, for example, the conductor can also be made of a conductive resin containing nanoparticles such as Cu or Ag.

[0253] The height H of the conductor 14 in the thickness direction Dt is preferably 10 to 300 μm, more preferably 20 to 30 μm.

[0254] <Shape of Conductor>

[0255] The plurality of conductors preferably have a cross-sectional area of 20 μm in a cross-section perpendicular to the length direction of the conductor, that is, the thickness direction Dt of the insulating film 12 2 The following conductor. The cross-sectional area is 20 μm 2 The following conductor is about 3.99 μm or less in terms of diameter d.

[0256] Furthermore, the average diameter d of the conductor 14 is more preferably 1 μm or less, even more preferably 5 - 500 nm, still more preferably 20 - 400 nm, yet more preferably 40 - 200 nm, and most preferably 50 - 100 nm.

[0257] The density of the conductor 14 is preferably 20,000 / mm 2 or more, more preferably 2,000,000 / mm 2 or more, even more preferably 10,000,000 / mm 2 or more, particularly preferably 50,000,000 / mm 2 or more, and most preferably 100,000,000 / mm 2 or more.

[0258] In addition, the center pitch p between adjacent conductors 14 is preferably 20 nm - 500 nm, particularly preferably 40 nm - 200 nm, and even more preferably 50 nm - 140 nm.

[0259] The average diameter of the conductor is obtained by photographing the surface of the anodic oxide film from directly above at a magnification of 100 - 10,000 times using a scanning electron microscope to obtain a photographic image. In the photographic image, at least 20 conductors that are annularly connected around are extracted, their diameters are measured and set as the opening diameters, and the average value of these opening diameters is calculated as the average diameter of the conductor.

[0260] In addition, the magnification can be appropriately selected within the above range to obtain a photographic image capable of extracting 20 or more conductors. And the opening diameter is measured as the maximum value of the distance between the ends of the conductor part. That is, since the shape of the opening part of the conductor is not limited to a substantially circular shape, in the case where the shape of the opening part is non-circular, the maximum value of the distance between the ends of the conductor part is set as the opening diameter. Therefore, for example, in the case of a conductor in which two or more conductors are integrated, it is regarded as one conductor, and the maximum value of the distance between the ends of the conductor part is set as the opening diameter.

[0261] <Protrusion>

[0262] The protrusion is a part of the conductor and is columnar. The protrusion can increase the contact area with the object to be joined, so it is preferably cylindrical.

[0263] The average protrusion length of the protrusion 14a and the average length of the protrusion 14b are preferably 30 nm - 500 nm, and as the upper limit value, it is more preferably 100 nm or less.

[0264] The average protruding length of the protruding portion 14a and the average length of the protruding portion 14b are the average values measured by obtaining a cross-sectional image of the protruding portion by using a field emission scanning electron microscope as described above and measuring the heights of the protruding portions at 10 points respectively based on the cross-sectional image.

[0265] [Resin layer]

[0266] As described above, the resin layer is provided on at least one of the front and back surfaces of the anodic oxide film, for example, the protruding portions of the buried conductors. That is, the resin layer covers the ends of the conductors protruding from the anodic oxide film and protects the protruding portions.

[0267] In order to exert the above functions, the resin layer is preferably a resin layer that exhibits fluidity in the temperature range of 50°C to 200°C and cures at 200°C or higher. The resin layer will be described in detail later.

[0268] The average protruding length of the conductor 14 is preferably less than the average thickness of the resin layer 16. When the average protruding lengths of the protruding portions 14a and 14b of the conductor 14 are both less than the average thickness of the resin layer 16, the protruding portions 14a and 14b are both buried in the resin layer portion 20a of the resin layer 16, and the conductor 14 is protected by the resin layer 16.

[0269] The average thickness of the resin layer 16 is the average distance from the front surface 12a of the insulating film 12 or the average distance from the back surface 12b of the insulating film 12. The average thickness of the above resin layer 16 is obtained by cutting the resin layer along the thickness direction Dt of the metal-filled microstructured body 10, observing the cross-section of the cut cross-section using a field emission scanning electron microscope (FE-SEM), measuring the distances from the front surface 12a of the insulating film 12 at 10 positions corresponding to the resin layer, and taking the average value of the 10 measured values. And, the distances from the back surface 12b of the insulating film 12 are measured at 10 positions corresponding to the resin layer, and the average value of the 10 measured values is taken.

[0270] The average thickness of the resin layer is preferably 200 to 1000 nm, more preferably 400 to 600 nm. When the average thickness of the resin layer is the above 200 to 1000 nm, the effect of protecting the protruding portion of the conductor 14 can be fully exerted.

[0271] In addition, regarding the sizes of the respective portions of the metal-filled microstructured body 10, unless otherwise specified, they are the average values obtained by cutting the metal-filled microstructured body 10 along the thickness direction Dt, observing the cross-section of the cut cross-section using a field emission scanning electron microscope (FE-SEM), and measuring 10 points at the positions corresponding to the respective dimensions.

[0272] [Stacked device]

[0273] Figure 14 This is a schematic diagram showing an example of a stacked device using the metal-filled microstructures of the embodiments of the present invention. In addition, Figure 14 In the stacked device 40 shown in Figure 8 and Figure 11 , the above-described metal-filled microstructures 10 (refer to

[0274] Figure 14 are used as the anisotropic conductive members 45 that exhibit anisotropic conductivity. Figure 8 and Figure 11 ), the conductors 14 of the metal-filled microstructures 10 (refer to Figure 8 and Figure 11 ) are arranged parallel to the stacking direction Ds, and the stacked device 40 has conductivity in the stacking direction Ds.

[0275] The stacked device 40 is a device in which one semiconductor element 44 is joined to one semiconductor element 42 in the stacking direction Ds, but is not limited thereto. It may also be a configuration in which three semiconductor elements are joined via the anisotropic conductive members 45. In this case, the stacked device is composed of three semiconductor elements and two anisotropic conductive members 45.

[0276] The stacked device 40 is not limited to having semiconductor elements, and may also be a substrate having electrodes. Substrates having electrodes are, for example, wiring substrates and interposers.

[0277] In addition, the form of the stacked device is not particularly limited, and examples include SoC (System on a chip), SiP (System in Package), PoP (Package on Package), PiP (Package in Package), CSP (Chip Scale Package), TSV (Through Silicon Via), and the like.

[0278] The stacked device 40 may have a semiconductor element that functions as a photosensor. For example, the semiconductor element and a sensor chip (not shown) are stacked in the stacking direction Ds. A lens may be provided in the sensor chip.

[0279] In this case, the semiconductor element is an element in which a logic circuit is formed, and its structure is not particularly limited as long as it can process the signals obtained by the sensor chip.

[0280] The sensor chip has a photosensor for detecting light. The photosensor is not particularly limited as long as it can detect light. For example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is used.

[0281] The structure of the lens is not particularly limited as long as it can focus light on the sensor chip. For example, a lens called a microlens can be used.

[0282] In addition, the above semiconductor elements 42, semiconductor element 44, and semiconductor element 46 can use elements having an element region (not shown). Regarding the element region, as described later. An element formation circuit or the like is formed in the element region. In the semiconductor element, for example, a redistribution layer (not shown) is provided.

[0283] In the stacked device, for example, it can be a combination of a semiconductor element having a logic circuit and a semiconductor element having a memory circuit. And, all the semiconductor elements can be made to have a memory circuit, or all can be made to have a logic circuit. And, as a combination of the semiconductor elements in the stacked device 40, it can be a combination of a sensor, an actuator, an antenna, etc. with a memory circuit and a logic circuit, and is appropriately determined according to the use of the stacked device 40 and the like.

[0284] 〔Objects to be joined to the structure〕

[0285] The objects to be joined to the structure exemplify the semiconductor elements as described above, and for example, have electrodes or element regions. As an element having an electrode, for example, a semiconductor element that exhibits a specific function alone is exemplified, and it also includes an element that exhibits a specific function when a plurality of them are aggregated. Furthermore, it also includes a component that only transmits an electrical signal, such as a wiring component, and a printed wiring board is also included in the component having an electrode.

[0286] The element region refers to a region where various elements that function as electronic components form a circuit or the like. The element region is, for example, a region where a memory circuit such as a flash memory, a logic circuit such as a microprocessor and an FPGA (field-programmable gate array), and a communication module such as a wireless tag and wirings are formed. In the element region, in addition to these, MEMS (Micro ElectroMechanical Systems) may also be formed. Examples of MEMS include sensors, actuators, and antennas. Among sensors, various sensors such as acceleration sensors, sound sensors, and optical sensors are included, for example.

[0287] As described above, an element formation circuit or the like is formed in the element region, and electrodes (not shown) are provided for electrically connecting the semiconductor chip to the outside. The element region has an electrode region where the electrodes are formed. In addition, the electrodes in the element region refer to, for example, Cu pillars. The electrode region refers to a region that substantially includes all the formed electrodes. However, when the electrodes are arranged dispersedly, the regions where each electrode is provided are also referred to as electrode regions.

[0288] As the form of the structure, it can be a monolithic form such as a semiconductor chip, a form such as a semiconductor wafer, or a form of a wiring layer.

[0289] Moreover, although the structure is joined to a joining object, the joining object is not particularly limited to the above-mentioned semiconductor elements, etc. For example, semiconductor elements in a wafer state, semiconductor elements in a chip state, printed wiring boards, and heat sinks, etc. become the joining objects.

[0290] 〔Semiconductor Element〕

[0291] In addition to what has been described above, examples of the semiconductor element 42 and the semiconductor element 44 include logic LSIs (Large Scale Integration) (e.g., ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), ASSPs (Application Specific Standard Products), etc.), microprocessors (e.g., CPUs (Central Processing Units), GPUs (Graphics Processing Units), etc.), memories (e.g., DRAMs (Dynamic Random Access Memories), HMCs (Hybrid Memory Cubes), MRAMs (Magnetic RAMs), PCMs (Phase-Change Memories), ReRAMs (Resistive RAMs), FeRAMs (Ferroelectric RAMs), flash memories (NAND (Not AND) flash), etc.), LEDs (Light Emitting Diodes) (e.g., micro flashes for mobile terminals, automotive use, light sources for projectors, LCD backlights, general lighting, etc.), power / devices, analog ICs (Integrated Circuits) (e.g., DC (Direct Current)-DC (Direct Current) converters, insulated gate bipolar transistors (IGBTs), etc.), MEMS (Micro Electro Mechanical Systems) (e.g., acceleration sensors, pressure sensors, oscillators, gyro sensors, etc.), radios (e.g.,GPS (Global Positioning System), FM (Frequency Modulation), NFC (Near - field communication), RFEM (RF Expansion Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), etc., discrete components, BSI (Back Side Illumination), CIS (Contact Image Sensor), camera module, CMOS (Complementary Metal Oxide Semiconductor), passive devices, SAW (Surface Acoustic Wave) filters, RF (Radio Frequency) filters, RFIPD (Radio Frequency Integrated Passive Devices), BB (Broadband), etc.

[0292] A semiconductor element is, for example, a single complete element, and a specific function such as a circuit or a sensor is achieved by the semiconductor element alone. The semiconductor element can have the function of an interposer. And, for example, it is also possible to stack a plurality of devices such as a logic chip and a memory chip having a logic circuit on a device having the function of an interposer. And, in this case, even if the electrode sizes of each device are different, bonding can be performed.

[0293] In addition, as a stacked device, it is not limited to the form of bonding a plurality of semiconductor elements in one semiconductor element, that is, the one - to - many form, and may also be the form of bonding a plurality of semiconductor elements to a plurality of semiconductor elements, that is, the many - to - many form.

[0294] The present invention is basically configured as described above. Above, the manufacturing method of the metal - filled micro - structure of the present invention has been described in detail, but the present invention is not limited to the above - described embodiments, and various improvements or changes can of course be made without departing from the gist of the present invention.

[0295] Examples

[0296] Hereinafter, examples will be given to illustrate the features of the present invention in more detail. The materials, reagents, amounts, ratios, operations, etc. shown in the following examples can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

[0297] In this example, the metal-filled microstructures of Examples 1 to 12 and the metal-filled microstructure of Comparative Example 1 were fabricated. Regarding the metal-filled microstructures of Examples 1 to 12 and Comparative Example 1, the conductivity was evaluated. The evaluation results of the conductivity are shown in Table 1 below. Hereinafter, the evaluation of the conductivity will be described.

[0298] <Conductivity>

[0299] A TEG chip (chained pattern) manufactured by WALTS CO., LTD. and an interposer were prepared, and they were placed above and below a chip bonder, and the positioning was adjusted in advance.

[0300] After adjusting the positioning, on the Cu pillar side of the interposer placed on the lower side, each of the fabricated metal-filled microstructures was overlapped, and using a room temperature bonding device (WP-100 (model), manufactured by PMT Corporation), at a temperature of 250 °C and a condition of 6 MPa, it was heated and pressed for 1 minute for bonding. The resistance between the chip wirings of the bonded sample was measured.

[0301] Hereinafter, Examples 1 to 12 and Comparative Example 1 will be described.

[0302] (Example 1)

[0303] The metal-filled microstructure of Example 1 will be described.

[0304] [Metal-filled microstructure]

[0305] [Fabrication of aluminum substrate]

[0306] An aluminum alloy containing Si: 0.06% by mass, Fe: 0.30% by mass, Cu: 0.005% by mass, Mn: 0.001% by mass, Mg: 0.001% by mass, Zn: 0.001% by mass, Ti: 0.03% by mass and the balance being Al and inevitable impurities was used to prepare molten metal. On the basis of performing molten metal treatment and filtration, an ingot with a thickness of 500 mm and a width of 1200 mm was fabricated by the DC (Direct Chill) casting method.

[0307] Next, after machining the surface with a surface planer to an average thickness of 10 mm, soaking was carried out at 550 °C for about 5 hours. When the temperature dropped to 400 °C, a rolled plate with a thickness of 2.7 mm was produced using a hot rolling mill.

[0308] In addition, after heat treatment at 500 °C using a continuous annealing furnace, it was finish-machined to a thickness of 1.0 mm by cold rolling to obtain an aluminum substrate of JIS (Japanese Industrial Standards) 1050 material.

[0309] After setting the width of the aluminum substrate to 1030 mm, the following respective treatments were carried out.

[0310] <Electrolytic polishing treatment>

[0311] Using an electrolytic polishing solution having the following composition, an electrolytic polishing treatment was carried out on the above-mentioned aluminum substrate under the conditions of a voltage of 25 V, a liquid temperature of 65 °C, and a liquid flow rate of 3.0 m / min.

[0312] The cathode was a carbon electrode, and a GP0110-30R (manufactured by TAKASAGO LTD.) was used as the power supply. Also, a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation.) was used to measure the flow rate of the electrolytic solution.

[0313] (Composition of electrolytic polishing solution)

[0314] · 85 mass% phosphoric acid (reagent manufactured by Wako Pure Chemical, Ltd.) 660 mL

[0315] · Pure water 160 mL

[0316] · Sulfuric acid 150 mL

[0317] · Ethylene glycol 30 mL

[0318] <Anodic oxidation treatment process>

[0319] Next, in accordance with the procedure described in Japanese Patent Laid-Open No. 2007-204802, an anodic oxidation treatment was carried out on the aluminum substrate after the electrolytic polishing treatment by the self-ordering method.

[0320] Using a 0.50 mol / L oxalic acid electrolytic solution, a pre-anodic oxidation treatment was carried out on the aluminum substrate after the electrolytic polishing treatment for 5 hours under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min.

[0321] Then, a stripping process of immersing the pre-anodized aluminum substrate in a mixed aqueous solution of 0.2 mol / L chromic anhydride and 0.6 mol / L phosphoric acid (liquid temperature: 50 °C) for 12 hours was carried out.

[0322] Then, a re-anodization process was carried out for 3 hours and 45 minutes under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min using an electrolyte of 0.50 mol / L oxalic acid to obtain an anodic oxide film with a thickness of 30 μm.

[0323] In addition, in the pre-anodization process and the re-anodization process, the cathode was set as a stainless steel electrode, and a GP0110-30R (manufactured by TAKASAGO LTD.) was used as the power supply. Also, a NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) was used as the cooling device, and a stirrer PS-100 (manufactured by EYELATOKYORIKAKIKAI CO, LTD.) was used as the stirring and heating device. In addition, a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation.) was used to measure the flow rate of the electrolyte.

[0324] <Barrier layer removal process>

[0325] Next, after the anodization process, an etching process of immersing in an alkaline aqueous solution obtained by dissolving zinc oxide in an aqueous sodium hydroxide solution (50 g / 1) to 2000 ppm at 30 °C for 150 seconds was carried out to remove the barrier layer at the bottom of the micropores (fine pores) of the anodic oxide film, and at the same time, zinc was precipitated on the surface of the exposed aluminum substrate.

[0326] And, the average thickness of the anodic oxide film after the barrier layer removal process was 30 μm.

[0327] <Metal filling process>

[0328] Next, an electrolytic electroplating process was carried out with the aluminum substrate as the cathode and platinum as the positive electrode.

[0329] Specifically, a copper electroplating solution with the following composition was used and constant current electrolysis was carried out to fabricate a metal-filled micro-structured body filled with nickel inside the micropores. Here, in the constant current electrolysis, an electroplating device manufactured by Yamamoto—MS Co., Ltd. was used, and a power supply (HZ-3000) manufactured by HOKUTO DENKO CORPORATION was used. After confirming the precipitation potential by cyclic voltammetry in the electroplating solution, the treatment was carried out under the following conditions.

[0330] (Copper electroplating solution composition and conditions)

[0331] · Copper sulfate 100 g / L

[0332] · Sulfuric acid 50 g / L

[0333] · Hydrochloric acid 15 g / L

[0334] · Temperature 25 °C

[0335] · Current density 10 A / dm 2

[0336] The surface of the anodic oxide film after filling the micropores with metal was observed by FE-SEM, and whether there was sealing of the micropores caused by the metal was observed in 1000 micropores. As a result of calculating the sealing rate (the number of sealed micropores / 1000), it was 98%.

[0337] Furthermore, the anodic oxide film after filling the micropores with metal was machined by FIB in the thickness direction, and a surface photograph of its cross section was taken by FE-SEM (magnification: 50,000 times). As a result of confirming the inside of the micropores, it was found that the inside of the sealed micropores was completely filled with metal.

[0338] <Surface metal protrusion process>

[0339] The structure after the metal filling process was immersed in an aqueous sodium hydroxide solution (concentration: 5% by mass, liquid temperature: 20 °C), and the immersion time was adjusted so that the height of the protruding part became 400 nm, and the surface of the anodic oxide film of aluminum was selectively dissolved to produce a structure in which the filled metal, that is, copper, protruded.

[0340] <Resin layer formation process>

[0341] A resin base material with an adhesive layer (RivaAlpha 3195MS, manufactured by NITTO DENKO CORPORATION.) that can be thermally peeled was pasted on the surface on the side where the aluminum substrate was not provided.

[0342] <Substrate removal process>

[0343] Next, the aluminum substrate was dissolved and removed by immersing it in a mixed solution of copper chloride / hydrochloric acid to produce a metal-filled micro-structure with an average thickness of 30 μm.

[0344] The diameter of the conduction path in the produced metal-filled micro-structure was 60 nm, the pitch between the conduction paths was 100 nm, and the density of the conduction paths was 57.7 million / mm 2 .

[0345] <Back surface metal protrusion process>

[0346] The structure after the metal filling process was immersed in an aqueous sodium hydroxide solution (concentration: 5% by mass, liquid temperature: 20 °C), and the immersion time was adjusted so that the height of the protruding part became 400 nm, and the surface of the anodic oxide film of aluminum was selectively dissolved to fabricate a structure in which the filling metal, i.e., copper, protruded.

[0347] <Heating process and removal process>

[0348] The structure was placed in a container. Then, regarding the atmosphere in the container, when the total pressure was set to 100%, the partial pressures of the respective gases were set to 80% nitrogen and 20% oxygen, and the atmosphere had a total pressure of 4.0×10 -2 Pa. Using a heater, the resin layer was heated at a temperature of 120 °C for 2 minutes, and then the resin layer was peeled off. The pressure inside the container was reduced using a vacuum pump, and the total pressure was adjusted.

[0349] In addition, a mixed gas was injected so that the gas ratio became the same as desired with respect to the total pressure. For example, when the gas ratio was N2:O2 = 80:20 and the total pressure was 4.0 Pa, after performing N2 purging (nitrogen purging), the pressure was reduced using a vacuum pump and adjusted to 3.2 Pa, and then O2 gas was injected to set the total pressure to 4.0 Pa.

[0350] Moreover, the peeling of the resin layer was performed in an atmospheric atmosphere.

[0351] (Example 2)

[0352] In Example 2, regarding the atmosphere of the heating process, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 80% nitrogen and 20% oxygen and the total pressure was 4.0 Pa, it was fabricated in the same manner as in Example 1.

[0353] (Example 3)

[0354] In Example 3, regarding the atmosphere of the heating process, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 80% nitrogen and 20% oxygen and the total pressure was 1.0×10 4 Pa, it was fabricated in the same manner as in Example 1.

[0355] (Example 4)

[0356] In Example 4, regarding the atmosphere of the heating process, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.8% nitrogen and 0.2% oxygen and the total pressure was 1.0×10 6 Pa, it was fabricated in the same manner as in Example 1.

[0357] (Example 5)

[0358] In Example 5, regarding the atmosphere in the heating step, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.8% argon and 0.2% oxygen, and the total pressure was 1.0×10 6 Pa, it was fabricated in the same manner as in Example 1.

[0359] (Example 6)

[0360] In Example 6, regarding the atmosphere in the heating step, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.8% hydrogen and 0.2% oxygen, and the total pressure was 1.0×10 6 Pa, it was fabricated in the same manner as in Example 1.

[0361] (Example 7)

[0362] In Example 7, regarding the atmosphere in the heating step, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.998% nitrogen and 0.002% oxygen, and the total pressure was 4.0 Pa, it was fabricated in the same manner as in Example 1.

[0363] (Example 8)

[0364] In Example 8, regarding the atmosphere in the heating step, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.998% argon and 0.002% oxygen, and the total pressure was 4.0 Pa, it was fabricated in the same manner as in Example 1.

[0365] (Example 9)

[0366] In Example 9, regarding the atmosphere in the heating step, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.998% hydrogen and 0.002% oxygen, and the total pressure was 4.0 Pa, it was fabricated in the same manner as in Example 1.

[0367] (Example 10)

[0368] In Example 10, in the resin layer forming step, the heat-peelable resin substrate with an adhesive layer was changed to Riva Alpha (registered trademark) 3195VS (manufactured by NITTO DENKO CORPORATION). Regarding the atmosphere in the heating step, when the total pressure was set to 100%, the partial pressures of the respective gases were set to 80% nitrogen and 20% oxygen, and the total pressure was 1.0×10 4 Pa. Except that the resin layer was heated at a temperature of 170°C for 2 minutes and the resin layer was peeled off, it was fabricated in the same manner as in Example 1.

[0369] (Example 11)

[0370] In Example 11, regarding the atmosphere of the heating process, when the total pressure was set to 100%, except that the partial pressures of the respective gases were 99.998% nitrogen and 0.002% oxygen, and the total pressure was 4.0 Pa, production was carried out in the same manner as in Example 10.

[0371] (Example 12)

[0372] In Example 12, except that in the resin layer forming process, the heat-peelable resin base material with an adhesive layer was changed to Somatac TE PS-2021TE (manufactured by SOMAR Corporation), production was carried out in the same manner as in Example 3.

[0373] (Comparative Example 1)

[0374] In Comparative Example 1, except that the total pressure of the atmosphere in the heating process was set to 1.0×10 6 Pa, production was carried out in the same manner as in Example 12.

[0375] [Table 1]

[0376] Atmosphere (partial pressure ratio of gas) Total pressure (Pa) Oxygen partial pressure (Pa) Heating temperature (°C) Conductivity (Ω) Example 1 Nitrogen 80%, oxygen 20% <![CDATA[4.0×10 -2 > <![CDATA[8.0×10 -3 > 120 170 Example 2 Nitrogen 80%, oxygen 20% 4.0 <![CDATA[8.0×10 -1 > 120 200 Example 3 Nitrogen 80%, oxygen 20% <![CDATA[1.0×10 4 > <![CDATA[2.0×10 3 > 120 250 Example 4 Nitrogen 99.8%, oxygen 0.2% <![CDATA[1.0×10 6 > <![CDATA[2.0×10 3 > 120 250 Example 5 Argon 99.8%, oxygen 0.2% <![CDATA[1.0×10 6 > <![CDATA[2.0×10 3 > 120 250 Example 6 Hydrogen 99.8%, oxygen 0.2% <![CDATA[1.0×10 6 > <![CDATA[2.0×10 3 > 120 230 Example 7 Nitrogen 99.998%, oxygen 0.002% 4.0 <![CDATA[8.0×10 -3 > 120 170 Example 8 Argon 99.998%, oxygen 0.002% 4.0 <![CDATA[8.0×10 -3 > 120 170 Example 9 Hydrogen 99.998%, oxygen 0.002% 4.0 <![CDATA[8.0×10 -3 > 120 150 Example 10 Nitrogen 80%, oxygen 20% <![CDATA[1.0×10 4 > <![CDATA[2.0×10 3 > 170 280 Example 11 Nitrogen 99.998%, oxygen 0.002% 4.0 <![CDATA[8.0×10 -3 > 170 200 Example 12 Nitrogen 80%, oxygen 20% <![CDATA[1.0×10 4 > <![CDATA[2.0×10 3 > 120 250 Comparative Example 1 Nitrogen 80%, oxygen 20% <![CDATA[1.0×10 6 > <![CDATA[2.0×10 5 > 120 400

[0377] As shown in Table 1, compared with Comparative Example 1, Examples 1 to 12 had a smaller resistance and better conductivity.

[0378] In Comparative Example 1, in the atmosphere of the heating process, the oxygen partial pressure exceeded 10,000 Pa and the resistance increased.

[0379] In Examples 1, 2, 7 to 9, 11, the oxygen partial pressure was 1.0 Pa or less, the resistance was smaller, and the conductivity was better.

[0380] In Examples 1 to 3, the lower the total pressure, the smaller the resistance and the better the conductivity.

[0381] In Examples 3, 10 and Examples 7, 11, the lower the heating temperature, the smaller the resistance and the better the conductivity.

[0382] Symbol Explanation

[0383] 10 - Metal-filled microstructures, 12 - Insulating film, 12a - Surface, 12b - Back surface, 13 - Pores, 14 - Conductor, 14a - Protrusion, 14b - Protrusion, 15 - Anodic oxidation film, 16 - Resin layer, 18 - Structure, 21 - Core, 30 - Aluminum substrate, 30a - Surface, 31 - Barrier layer, 32c - Bottom, 32d - Surface, 35 - Metal, 35a - Metal layer, 35b - Metal, 40 - Stacked device, 42 - Semiconductor element, 44 - Semiconductor element, 45 - Anisotropic conductive component, Ds - Stacking direction, Dt - Thickness direction, H - Height, d - Average diameter, ht - Thickness, p - Center pitch.

Claims

1. A method for manufacturing a metal-filled micro-structure, comprising: a preparation step of preparing a structure, the structure having an insulating film and a plurality of conductors penetrating the insulating film in the thickness direction and arranged in an electrically insulated state from each other, the conductors protruding from at least one surface in the thickness direction of the insulating film, and the structure having a resin layer covering the surface of the insulating film from which the conductors protrude; a heating step of heating at least the resin layer in an atmosphere with an oxygen partial pressure of 0.8 Pa or less; and a removing step of removing the resin layer heated by the heating step from the insulating film, wherein the heating step is a step for making the resin layer easily removable in order to remove the resin layer, and the resin layer contains a thermally peelable binder.

2. The method for manufacturing a metal-filled micro-structure according to claim 1, wherein in the heating step, the partial pressure of the inert gas in the atmosphere is 85% or more of the total pressure of the atmosphere.

3. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein in the heating step, the partial pressure of the reducing gas in the atmosphere is 85% or more of the total pressure of the atmosphere.

4. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein in the heating step, the total pressure of the atmosphere is 5.0 Pa or less.

5. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein the conductor contains a base metal.

6. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein A plurality of the conductors have a cross-sectional area of 20 μm or less in a cross-section perpendicular to the length direction of the conductors. 2 The following conductors.

7. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein the reaching temperature of the resin layer in the heating step is 150°C or less.

8. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein the conductors protrude from both surfaces in the thickness direction of the insulating film, and the resin layers are respectively provided on both surfaces in the thickness direction of the insulating film.

9. The method for manufacturing a metal-filled micro-structure according to claim 1 or 2, wherein the insulating film is an anodic oxidation film.

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