Method for producing metal-filled microstructure

Abstract

The present invention provides a method for manufacturing a metal-filled microstructure that has excellent transport properties and suppresses deterioration of insulation performance. The method for manufacturing a metal-filled microstructure comprises: a forming step, in which an oxide film having a plurality of pores is formed in a forming area surrounded by a frame portion arranged at the outer edge of a valve metal part, thereby obtaining a structure having a valve metal part and an oxide film; a filling step, in which metal is filled in the plurality of pores of the oxide film of the structure; and a holding step, in which the metal-filled part obtained by filling the plurality of pores of the oxide film of the structure through the filling step is exposed to an environment with a relative humidity of 10 to 30% for more than 24 hours. The average diameter of the plurality of pores is 1 μm or less.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a metal-filled microstructure using a valve metal component, and more particularly to a method for manufacturing a metal-filled microstructure having excellent transportability and good insulation performance. Background Art

[0002] A structure in which a plurality of through holes provided in an insulating substrate are filled with a conductive material such as a metal has been one of the fields that has attracted attention in nanotechnology in recent years, and is expected to be used as an anisotropic conductive member, for example.

[0003] Anisotropic conductive components are inserted between electronic parts such as semiconductor elements and circuit boards, and electrical connection between the electronic parts and the circuit board can be achieved simply by applying pressure. Therefore, they are widely used as electrical connection components for electronic parts such as semiconductor elements and as inspection connectors for functional inspections.

[0004] In particular, the miniaturization of electronic parts such as semiconductor elements is remarkable. In the conventional methods such as direct connection to wiring substrates such as wire bonding, flip chip bonding and thermocompression bonding, the stability of the electrical connection of electronic parts cannot be fully guaranteed, so anisotropic conductive components have attracted much attention as electronic connection components.

[0005] For example, Patent Document 1 describes a method for producing a microstructure by forming a microstructure with a density of 10 million pieces / mm 2 The substrate has microporous through-holes with a density above 100, and a part of the microporous through-holes is filled with a substance other than the material of the substrate. In the method for manufacturing a microstructure of Patent Document 1, the substrate is aluminum oxide, and at least the following treatments are sequentially performed on the aluminum substrate: (A) a treatment for forming an oxide film having micropores by anodizing; (B) a treatment for removing aluminum from the oxide film obtained by the above-mentioned treatment (A); (C) a treatment for penetrating a part of the micropores existing in the oxide film from which aluminum is removed by the above-mentioned treatment (B); (D) a treatment for filling the micropores penetrated by the above-mentioned treatment (C) with a substance other than the oxide film; and (E) a surface smoothing treatment for smoothing the surface and back of the oxide film after the above-mentioned treatment (D) by chemical mechanical polishing.

[0006] Previous technical literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2013-167023 Summary of the invention

[0009] Technical issues to be solved by the invention

[0010] In the method for manufacturing a microstructure of the above-mentioned patent document 1, a microstructure in which micropores are filled with substances other than the material of the substrate can be obtained. As described above, in the method for manufacturing a microstructure of the above-mentioned patent document 1, (D) a process of filling the micropores penetrated with substances other than the oxide film, and (E) a surface smoothing process of smoothing the surface and back of the oxide film after the above-mentioned (D) treatment by chemical mechanical polishing are implemented, but sometimes the above-mentioned (D) and the above-mentioned (E) treatments are not performed continuously, but the above-mentioned (E) treatment is performed after a predetermined time after the above-mentioned (D), for example, by transportation. In this case, the filling portion may be damaged by transportation, etc. In addition, the insulation performance of the microstructure may also be deteriorated due to the influence of the environment between the processes, etc.

[0011] An object of the present invention is to provide a method for producing a metal-filled microstructure having excellent transportability and suppressed deterioration of insulation performance.

[0012] Means for solving technical problems

[0013] In order to achieve the above-mentioned purpose, one embodiment of the present invention provides a method for manufacturing a metal-filled microstructure, which comprises: a forming step, forming an oxide film having a plurality of pores in a forming area surrounded by a frame portion arranged at the outer edge of a valve metal part, thereby obtaining a structure having a valve metal part and an oxide film; a filling step, filling the structure with metal in the plurality of pores of the oxide film; and a maintaining step, exposing the metal-filled part obtained by filling the structure with metal in the plurality of pores of the oxide film through the filling step to an environment with a relative humidity of 10 to 30% for more than 24 hours, and the average diameter of the plurality of pores is less than 1 μm.

[0014] Preferably, the valve metal part consists of aluminum.

[0015] It is preferable that the oxide film is an anodic oxide film.

[0016] The preferred anodic oxide film is Al 2 O 3 .

[0017] Preferably, in the filling step, the metal filled into the plurality of pores of the oxide film is copper.

[0018] The filling step is preferably a step of filling the plurality of pores with metal by forming a metal layer on the surface of the structure. In the filling step, a metal layer having a thickness of 100 μm or less is formed on the frame portion.

[0019] It is preferable to include a metal layer removing step of removing the metal layer formed on the surface of the structure after the holding step.

[0020] It is preferable to include a surface smoothing treatment step of smoothing the surface of the oxide film after the metal layer removal step.

[0021] It is preferred that chemical mechanical polishing, dry etching or grinding be used for smoothing in the surface smoothing treatment step.

[0022] Effects of the Invention

[0023] According to the present invention, it is possible to obtain a method for producing a metal-filled microstructure that is excellent in transportability and suppresses deterioration in insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0025] Figure 2 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0026] Figure 3 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0027] Figure 4 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0028] Figure 5 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0029] Figure 6 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0030] Figure 7 Yes means Figure 5 A plan view of the structure shown.

[0031] Figure 8 It is a magnified representation Figure 7 Schematic plan view of region Q of the structure shown.

[0032] Fig. 9 It is a magnified representation Figure 7 Schematic cross-sectional view of region Q of the structure shown.

[0033] Fig.10 About Figure 6 The metal-filled components shown are enlarged to represent the equivalent Figure 7A schematic plan view of a portion of region Q of the structure is shown.

[0034] Fig.11 About Figure 6 The metal-filled components shown are enlarged to represent the equivalent Figure 7 A schematic cross-sectional view of a portion of region Q of the structure is shown.

[0035] Fig.12 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0036] Fig.13 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0037] Fig.14 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0038] Fig.15 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0039] Fig.16 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0040] Fig.17 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0041] Fig.18 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0042] Fig.19 This is a schematic cross-sectional view showing one step of the first example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0043] Fig. 20 This is a schematic cross-sectional view showing one step of the second example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0044] Fig.21 This is a schematic cross-sectional view showing one step of the second example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0045] Fig. 22This is a schematic cross-sectional view showing one step of the second example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0046] Fig.23 This is a schematic cross-sectional view showing one step of the second example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0047] Fig.24 This is a schematic cross-sectional view showing one step of the second example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0048] Fig.25 This is a schematic cross-sectional view showing one step of the third example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0049] Fig.26 This is a schematic cross-sectional view showing one step of the third example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0050] Fig. 27 This is a schematic cross-sectional view showing one step of the third example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0051] Fig.28 This is a schematic cross-sectional view showing one step of the third example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0052] Fig.29 This is a schematic cross-sectional view showing one step of the third example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0053] Fig.30 This is a schematic cross-sectional view showing one step of the fourth example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0054] Fig.31 This is a schematic cross-sectional view showing one step of the fourth example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0055] Fig.32 This is a schematic cross-sectional view showing one step of the fourth example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0056] Fig.33 This is a schematic cross-sectional view showing one step of the fourth example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0057] Fig.34This is a schematic cross-sectional view showing one step of the fourth example of the method for producing the metal-filled microstructure according to the embodiment of the present invention.

[0058] Fig.35 It is a plan view showing an example of the structure of the metal-filled microstructure according to the embodiment of the present invention.

[0059] Fig.36 This is a schematic cross-sectional view showing an example of the structure of the metal-filled microstructure according to the embodiment of the present invention.

[0060] Fig.37 This is a schematic perspective view showing an example of a container used in the holding step according to the embodiment of the present invention.

[0061] Fig.38 This is a schematic cross-sectional view showing an example of a storage container used in the holding step according to the embodiment of the present invention.

[0062] Fig.39 This is a schematic perspective view showing an example of a storage bag used in the holding step according to the embodiment of the present invention.

[0063] Fig.40 This is a schematic diagram showing another example of the container used in the holding step according to the embodiment of the present invention.

[0064] Fig.41 This is a schematic perspective view showing an example of a storage method used in the holding step according to the embodiment of the present invention. DETAILED DESCRIPTION

[0065] Hereinafter, the method for producing the metal-filled microstructure of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0066] In addition, the drawings described below are exemplary drawings for explaining the present invention, and the present invention is not limited to the drawings shown below.

[0067] In addition, the following "to" indicating a numerical range means that the numerical values ​​described on both sides are included. a is the value α b ~Value β c refers to ε a The range includes the value α b and the value β c The range of, if expressed in mathematical symbols, is α b ≤ε a ≤β c .

[0068] Unless otherwise specified, angles such as "orthogonal" include the error ranges generally allowed in the corresponding technical field. Also, regarding humidity and time, unless otherwise specified, they include the error ranges generally allowed in the corresponding technical field.

[0069] Regarding metal-filled microstructures, the insulation resistance of oxide films with pores (through holes) fluctuated. The changes in insulation resistance were examined and found to be affected by the storage location and storage time. The following phenomena were found: even in a warehouse without special temperature control, the insulation resistance was good in cold seasons, and even in a building with temperature control, the insulation resistance deteriorated irregularly.

[0070] As a result of in-depth research, it was found that the moisture in the oxide film with pores (through holes) may have an effect, rather than the temperature during storage. The relationship between the storage conditions, especially humidity, and insulation performance was examined, and it was found that stable insulation resistance can be obtained by keeping the humidity within a certain range, which led to the completion of the present invention. The following is a specific description of the method for manufacturing a metal-filled microstructure.

[0071] [First Example of Method for Producing Metal-Filled Microstructure]

[0072] Figure 1 to Figure 6 and Figures 12 to 19 This is a schematic cross-sectional view showing an example of the first example of the method for producing a metal-filled microstructure according to an embodiment of the present invention in order of steps. Figure 7 yes Figure 5 The plan view of the structure shown, Figure 8 It is a magnified representation Figure 7 A schematic plan view of a region Q of the structure shown, Fig. 9 It is a magnified representation Figure 7 A schematic cross-sectional view of region Q of the structure shown. And, Fig.10 About Figure 6 The metal-filled components shown are enlarged to represent the equivalent Figure 7 A schematic plan view of a portion of region Q of the structure shown, Fig.11 About Figure 6 The metal-filled components shown are enlarged to represent the equivalent Figure 7 A schematic cross-sectional view of a portion of region Q of the structure is shown.

[0073] The metal-filled microstructure is obtained by performing an anodic oxidation treatment on the surface of a valve metal component. The metal-filled microstructure has an insulating substrate composed of an anodic oxide film of a valve metal. The valve metal is aluminum, etc., but is not particularly limited to aluminum. As an insulating substrate, an anodic oxide film of aluminum is used as an example for description. Therefore, in the following description, an aluminum substrate is used as an example for description as a valve metal component.

[0074] like Figure 1 As shown, an aluminum substrate is prepared as the valve metal member 11 .

[0075] Then, if Figure 2 As shown, the mask 12 is formed only on the outer edge 11b of the surface 11a of the valve metal part 11. The mask 12 is not particularly limited as long as it is an electrically insulating mask, and for example, a known resist film used for forming a semiconductor element can be used. Regarding the mask 12, for example, after forming a resist film on the entire surface 11a of the valve metal part 11, the resist film except for the outer edge 11b of the surface 11a of the valve metal part 11 is removed by photolithography, and the mask 12 is formed only on the outer edge 11b. In addition, as the mask 12, for example, a resist pen can be used to form a resist film only on the outer edge 11b of the surface 11a of the valve metal part 11. In addition, an acid-resistant adhesive resin tape can be attached to the outer edge 11b of the surface 11a of the valve metal part 11 as the mask 12.

[0076] In the surface 11a of the valve metal member 11, a region 11c surrounded by the mask 12 is an anodic oxide film 16 (refer to Figure 5 ) formation area.

[0077] Next, an anodic oxide film forming step is performed in which an anodic oxidation treatment is performed using the valve metal member 11 as an electrode, and the region 11c of the valve metal member 11 surrounded by the mask 12 is formed into an anodic oxide film. Figure 5 ) is an insulating substrate.

[0078] In the anodic oxide film forming step, the valve metal member 11 is subjected to an anodic oxidation treatment using the valve metal member 11 as an anode electrode. Figure 3 As shown, an anodic oxide film 11d is formed in the region 11c of the valve metal member 11. In the anodic oxidation treatment, for example, current may be applied from the back side of the valve metal member 11 or from the outer edge 11b side.

[0079] In the anodizing treatment, as described above, the valve metal member 11 is used as an electrode, and the region 11c (refer to Figure 3 ) becomes the formation area of ​​the anodized film 11d, and the valve metal member 11 below the mask 12 (reference Figure 2 ) is the outer edge 15b (reference Figure 4 ) and become the frame portion 15d (reference Figure 4 ).

[0080] The anodized film 11d is formed in the above-mentioned region 11c, but the valve metal member 11 below the mask 12 is not anodized. In this way, the valve metal member 11 is not entirely formed into the anodized film 11d, and the region of the valve metal member 15 is retained even after the anodizing treatment. Thus, the frame portion 15d of the valve metal member 15 formed by the valve metal member 15 is arranged on the outer edge 15b of the valve metal member 15. The anodized film 16 is formed in the region 15c surrounded by the frame portion 15d (see Figure 4 ).

[0081] In addition, since the valve metal member 11 is made of aluminum, an anodic oxide film 16 is formed as an oxide film. The anodic oxide film 16 is made of Al. 2 O 3 Membrane composition.

[0082] The anodized film 11d has a plurality of micropores when it is formed. However, among the plurality of micropores, there are also micropores that do not penetrate in the thickness direction Dt. In addition, there is a barrier layer (not shown) at the bottom of the micropores. Therefore, Figure 3 The anodized film 11d shown removes the barrier layer, such as Figure 4 As shown, a plurality of through holes 17 extending in the thickness direction Dt are formed in the anodized film 16 .

[0083] Through the above steps, an oxide film (anodized film 16) having a plurality of pores (through holes 17) is formed in the region 15c surrounded by the frame portion 15d disposed on the outer edge 15b of the valve metal member 15, thereby obtaining a structure 18 having the valve metal member 15 and the oxide film (anodized film 16). For example, Figure 7 and Figure 8 As shown in FIG. 1 , an anodic oxide film 16 is formed on the surface 15a of the valve metal member 15, and a frame portion 15d exists around the anodic oxide film 16. Fig. 9 As shown, the surface 16a of the anodized film 16 and the surface of the frame portion 15d are substantially on the same plane.

[0084] As mentioned above, Figure 3 The anodized film forming process shown in FIG. Figure 4 The step of forming the plurality of through holes 17 extending in the thickness direction Dt is a step of obtaining the structure 18 .

[0085] 〔Aluminum substrate〕

[0086] The aluminum substrate is not particularly limited. Specific examples include: pure aluminum plates; alloy plates with aluminum as the main component and containing trace amounts of heterogeneous elements; substrates with high-purity aluminum vapor-deposited on low-purity aluminum (such as recycled materials); substrates with high-purity aluminum coated on the surfaces of silicon wafers, quartz, glass, etc. by vapor deposition, sputtering, etc.; resin substrates laminated with aluminum; and the like.

[0087] In the aluminum substrate, the aluminum purity of the surface on the side where the anodized film is formed by anodizing treatment is preferably 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.

[0088] The aluminum substrate is not particularly limited as long as an anodized film can be formed thereon, and for example, JIS (Japanese Industrial Standards) 1050 material and 1070 material can be used.

[0089] The surface of the aluminum substrate on the side to be anodized is preferably subjected to heat treatment, degreasing treatment, and mirror finishing treatment in advance.

[0090] 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 Application Laid-Open No. 2008-270158 can be performed.

[0091] The mirror finishing treatment before the anodizing treatment is, for example, electrolytic polishing, and in the electrolytic polishing, for example, an electrolytic polishing liquid containing phosphoric acid is used.

[0092] Here, specifically, examples of the valve metal include tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and the like in addition to the above-mentioned aluminum.

[0093] 〔Anodizing process〕

[0094] A conventionally known method can be used for the anodizing treatment, but a self-regularization method or a constant voltage treatment is preferably used from the viewpoint of improving the regularity of the micropore arrangement and ensuring the anisotropic conductivity of the metal-filled microstructure.

[0095] Here, regarding the self-regulation method and constant pressure treatment of the anodizing treatment, the same method as in paragraphs

[0056] to

[0108] and [ Figure 3 ] are the same processing as the processing described in ].

[0096] In the anodized film having a plurality of micropores, as described above, a barrier layer (not shown) exists at the bottom of the micropores, and a barrier layer removal step of removing the barrier layer is provided.

[0097] [Barrier layer removal process]

[0098] The barrier layer removal step is a step of removing the barrier layer of the anodized film using, for example, an alkaline aqueous solution containing ions of the metal M1 having a higher hydrogen overvoltage than aluminum.

[0099] The barrier layer is removed by the barrier layer removal step, and a conductive layer made of the metal M1 is formed at the bottom of the microhole.

[0100] Here, hydrogen overvoltage refers to the voltage required to generate hydrogen. For example, the hydrogen overvoltage of aluminum (Al) is -1.66 V (Journal of the Chemical Society of Japan, 1982, (8), p1305-1313). In addition, the following shows an example of a metal M1 having a higher hydrogen overvoltage than aluminum and its hydrogen overvoltage value.

[0101] <Metal M1 and hydrogen (1N H 2 SO 4 ) Overvoltage>

[0102] Platinum (Pt): 0.00V

[0103] Gold (Au): 0.02V

[0104] Silver (Ag): 0.08V

[0105] Nickel (Ni): 0.21V

[0106] Copper (Cu): 0.23V

[0107] Tin (Sn): 0.53V

[0108] Zinc (Zn): 0.70V

[0109] The through hole 17 (pore) can also be formed by expanding the diameter of the micropore and removing the barrier layer. In this case, the expansion of the micropore is performed by a pore expansion process. The pore expansion process is a process for expanding the pore diameter of the micropore by immersing the anodized film in an acidic aqueous solution or an alkaline aqueous solution to dissolve the anodized film. In the pore expansion process, an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof, or an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. can be used.

[0110] In addition, the barrier layer at the bottom of the micropores can also be removed during the pore expansion treatment. By using a sodium hydroxide aqueous solution in the pore expansion treatment, the micropores can be expanded in diameter and the barrier layer can be removed.

[0111] The hole expansion process cannot form a conductive layer in the same way as the barrier layer removal process. Therefore, after the hole expansion process, the conductive layer can be formed by treating again with an aqueous solution containing ions of the metal M1 having a higher hydrogen overvoltage than aluminum, or by performing multiple stages of treatment with aqueous solutions containing different metals.

[0112] Next, from Figure 4 Remove the mask 12 (reference Figure 5 Then, a filling process is performed, in which Figure 5 The structure 18 shown in the figure is formed by filling metal in the plurality of through holes 17 of the anodized film 16. The structure 18 is formed by filling metal in the plurality of through holes 17 of the anodized film 16, thereby forming a Figure 6 As shown, a conductive path 20 is formed to obtain a metal filling member 21. The filling process of the filling metal will be described in detail later.

[0113] In the filling step, it is sufficient to fill the plurality of through holes 17 of the anodized film 16 with metal. Figure 5 , Fig.10 and Fig.11 As shown in FIG. 1 , the metal layer 19 may be formed on the surface of the structure 18, that is, on the frame portion 15d of the metal filling member 21 and on the surface 16a of the anodized film 16, so that the metal is filled in the plurality of through holes 17. In this case, it is preferred that the metal layer 19 be formed on the frame portion 15d with a thickness δ ( Figure 5 and Fig.11 ) to form the metal layer 19. The lower limit of the thickness δ of the metal layer 19 is, for example, 2 μm.

[0114] When the thickness δ of the metal layer 19 is 2 to 100 μm, the conduction path 20 is protected, and damage to the anodized film 16 and the conduction path 20 is suppressed when the metal filling member 21 is conveyed. In addition, for example, by extending the plating time, the thickness δ of the metal layer 19 can be increased. In the filling step, the metal is filled beyond the surface 16a of the anodized film 16, and the metal layer 19 is formed on the frame portion 15d.

[0115] In the filling step, the metal is filled in the through-hole 17 up to the surface 16 a of the anodized film 16 , and thus the metal layer 19 may not be provided.

[0116] The thickness δ of the metal layer 19 is obtained by cutting the metal filling member 21 in the thickness direction, observing the cross section of the cut section using a FE-SEM (Fieldemission-Scanning Electron Microscope), and measuring the average value of 10 points.

[0117] Furthermore, the thickness of the bottom portion 15 e of the valve metal member 15 is not particularly limited, but is preferably 20 μm or more, and more preferably 30 to 50 μm.

[0118] The thickness of the bottom 15 e of the valve metal member 15 is similar to the thickness δ of the metal layer 19 . The metal filling member 21 is cut in the thickness direction, and the cross section is observed using FE-SEM to measure the average value of 10 points.

[0119] The metal filling component 21 is obtained by the filling step of filling the metal. Next, a holding step is performed in which the metal filling component 21 is exposed to an environment with a relative humidity of 10 to 30% for more than 24 hours. The holding step is not particularly limited as long as it is a step in which the metal filling component 21 is exposed to an environment with a relative humidity of 10 to 30% for more than 24 hours. The holding step will be described later.

[0120] 〔Filling process〕

[0121] <Filling Metal>

[0122] The metal as the conductive material filled in the through hole 17 preferably has a resistivity of 10 3 As specific examples of materials with a resistance of Ω·cm or less, preferably gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni), and zinc (Zn) are exemplified.

[0123] In addition, as the conductive material, from the viewpoint of conductivity, Cu, Au, Al, and Ni are preferred, Cu and Au are more preferred, and Cu is further preferred.

[0124] <Filling method>

[0125] As a plating method for filling the inside of the through hole with metal, for example, an electroplating method or an electroless plating method can be used.

[0126] Here, in the conventionally known electroplating method used for coloring, it is difficult to selectively precipitate (grow) metal in the hole with a high aspect ratio. The reason is believed to be that even if the precipitated metal is consumed in the hole and electrolysis is performed for a certain period of time or more, the plating layer will not grow.

[0127] Therefore, when metal is filled by electroplating, a pause time needs to be set during pulse electrolysis or constant potential electrolysis. The pause time needs to be 10 seconds or more, preferably 30 to 60 seconds.

[0128] Furthermore, it is also preferable to apply ultrasonic waves in order to promote stirring of the electrolyte solution.

[0129] In addition, electrolysis voltage is generally below 20V, and expectation is below 10V, but preferably measures the precipitation potential of the target metal in the employed electrolytic solution in advance, and carries out constant potential electrolysis at this potential+1V.In addition, when carrying out constant potential electrolysis, expectation can use cyclic voltammetry simultaneously, can use the constant potential instrument device of Solartron company, BAS Inc., HOKUTO DENKO CORPORATION, IVIUM company etc.

[0130] In the above-mentioned electroplating method, constant current electrolysis can also be used, but it is preferred that the current value is set so that the voltage during electrolysis is within the same range as the above-mentioned electrolysis voltage. In this case, a common DC power supply can be used, for example, a known device of Matsusada Precision Inc., TAKASAGO LTD., KIKUSUI ELECTRONICS CORP., TEXIOTECHNOLOGY CORPORATION, etc. can be used. In addition, in the above-mentioned electroplating method, pulse electrolysis commonly used in plating treatment can also be used.

[0131] As the plating solution, a conventionally known plating solution can be used.

[0132] Specifically, when copper is precipitated, an aqueous solution containing copper sulfate is generally used, but the concentration of copper sulfate is preferably 1 to 300 g / L, more preferably 100 to 200 g / L. Furthermore, if hydrochloric acid is added to the electrolyte, precipitation can be promoted. In this case, the concentration of hydrochloric acid is preferably 10 to 20 g / L.

[0133] Furthermore, the plating solution may contain an acid, and the acid concentration is preferably 0.01 to 1 mol / L.

[0134] An additive may be added to the electrolyte solution. Examples of the additive to be added to the electrolyte solution are shown below. The additive may provide the following effects.

[0135] As additives, components called brighteners and smoothing agents may also be added. In the adhesion inhibition effect, molecules or ions are adsorbed or precipitated alone to inhibit the plating reaction. Saccharin, benzothiazole, thiourea, Janus Green B (JGB), benzyl acetone, lead, bismuth, etc. are equivalent to components with adhesion inhibition effect.

[0136] In the formation of interfacial complexes, a small amount of complex-forming ions adsorbed on the surface coordinate with metal ions to form ion bridges or electrical bridges, thereby promoting the precipitation reaction. - 、SCN -, sulfur compounds (thiourea, disodium 3,3′-dithiobis(1-propanesulfonic acid) (SPS), dithiothiazole (DMTD), etc.), boric acid, oxalic acid, malonic acid, etc. are considered to correspond to this.

[0137] In the film formation, surfactants or polymers gently adhere to the plating surface to form a film and inhibit the plating reaction. Representative examples include PEG (polyethylene glycol), polyethylene glycol mono-4-nonylphenyl ether (PEGNPE), polyvinyl alcohol, gelatin, etc.

[0138] In the electrolytic consumption mechanism, molecules or ions are rapidly electrolytically reduced on the plating surface, and the reaction rate is determined by the diffusion and transport of these molecules or ions to the surface. As a result, the unevenness of the plating surface shape is reduced. Representative examples include unsaturated alcohols (butynediol, propargyl alcohol, coumarin, etc.), NO 3 - , Fe 3 + wait.

[0139] Furthermore, the surface tension of the plating solution is preferably adjusted to be as low as possible, and the surface tension is preferably 60 mN / m or less, which is lower than that of pure water. A surfactant or an organic solvent may also be added to adjust the surface tension.

[0140] The pH (hydrogen ion index) of the plating solution is preferably adjusted, and the pH is preferably 1 or more.

[0141] When gold is to be deposited, it is preferred to perform plating by alternating current electrolysis using a sulfuric acid solution of tetrachlorogold.

[0142] Furthermore, in the electroless plating method, it takes a long time to completely fill the hole consisting of the through-hole having a high aspect ratio with the metal, and therefore it is preferable to fill the through-hole with the metal by using the electroplating method.

[0143] After the maintenance process, Fig.12 As shown, for the metal filling member 21 , a support 24 is provided on the back surface 16 b of the anodized film 16 using a resin base material 22 .

[0144] For example, a functional adsorption film is used as the resin substrate 22. As the functional adsorption film, Q-chuck (registered trademark) (manufactured by MARUISHI SANGYO CO., LTD.) or the like can be used.

[0145] The support body 24 preferably has the same outer shape as the anodized film 16. The support body 24 supports the anodized film 16 in the subsequent process. By installing the support body 24, the workability is improved.

[0146] Then, if Fig.13As shown, for example, a metal layer removal step is performed to remove the metal layer 19 of the metal filling member 21. In the metal layer removal step, for example, an adhesive tape is used to peel off the metal layer 19. The average diameter of the plurality of through holes 17 is as small as 1 μm or less, and the metal layer can be easily removed using an adhesive tape.

[0147] In addition, the method of the metal layer removal step is not particularly limited as long as the metal layer 19 can be removed.

[0148] Preferably with Fig.13 The surface smoothing treatment process of smoothing the surface 16a of the anodized film 16 in the state where the metal layer 19 is removed is shown. The surface smoothing treatment process can be smoothed by chemical mechanical polishing (CMP), dry etching or grinding, and chemical mechanical polishing (CMP), dry etching and grinding can also be combined for smoothing. When performing chemical mechanical polishing (CMP), different abrasive grains can be combined for polishing. In any method, the surface roughness (arithmetic mean roughness Ra (JIS B 0601: 2001)) of the finished surface is preferably set to 0.02μm or less.

[0149] By performing the surface smoothing process after the metal layer removal process, the amount of polishing in the surface smoothing process can be reduced, and polishing can be easily performed. Thus, the time required for the surface smoothing process can be shortened, and smoothing can be easily performed.

[0150] The metal layer removal step and the surface smoothing step are performed after the holding step. In the metal layer removal step and the surface smoothing step, a support member is provided on the back surface of the valve metal member 15 for the purpose of conveying and the like.

[0151] After the surface smoothing process, Fig.14 As shown, a portion of the anodized film 16 and the frame portion 15d is removed in the thickness direction Dt in a manner in which the support body 24 is installed, so that the metal filled above is made to protrude further than the surface 16a of the anodized film 16. That is, the conduction path 20 may also protrude from the surface 16a of the anodized film 16. The portion of the conduction path 20 protruding from the surface 16a of the anodized film 16 is referred to as a protruding portion 20a. The process of making the metal filled above protrude further than the surface 16a of the anodized film 16 is referred to as a metal protruding process.

[0152] 〔Metal protrusion process〕

[0153] For the removal of the above-mentioned part of the anodized film 16, for example, a metal that does not dissolve the metal constituting the conductive path 20 but dissolves the anodized film 16, that is, aluminum oxide (Al 2 O 3). A portion of the anodized film 16 is removed by bringing the acidic aqueous solution or alkaline aqueous solution into contact with the anodized film 16 having the through-holes 17 filled with metal. The method for bringing the acidic aqueous solution or alkaline aqueous solution into contact with the anodized film 16 is not particularly limited, and examples thereof include immersion method, spray method, and rotation treatment method. Among them, from the viewpoint of uniformity, a treatment method using a rotation processor is preferably used. As a rotation processor, known products of MIMASU SEMICONDUCTOR INDUSTRY CO., LTD., Hitachi High-Tech Corporation., SCREEN Holdings Co., Ltd., DAIN IPPON SCREENMFG.CO., LTD., ActesKyosan inc., Kanamex Co., Ltd., etc. can be used.

[0154] When an acidic aqueous solution is used, an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid, or a mixture thereof is preferably used. Among them, an aqueous solution not containing chromic acid is preferred from the viewpoint of excellent safety. 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.

[0155] When using an alkaline aqueous solution, it is preferred to use an aqueous solution of at least one alkali selected from sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. The temperature of the alkaline aqueous solution is preferably 20 to 35°C.

[0156] Specifically, for example, a 50 g / L, 40° C. phosphoric acid aqueous solution, a 0.5 g / L, 30° C. sodium hydroxide aqueous solution, or a 0.5 g / L, 30° C. potassium hydroxide aqueous solution is preferably used.

[0157] The immersion time in the acidic aqueous solution or alkaline aqueous solution is preferably 8 to 120 minutes, more preferably 10 to 90 minutes, and still more preferably 15 to 60 minutes. Here, the immersion time refers to the sum of the immersion times when the immersion treatments are repeated for a short time. In addition, between the immersion treatments, a cleaning treatment may be performed, and a neutralization treatment may also be performed.

[0158] Furthermore, when the produced metal-filled fine structure 32 is used as an anisotropic conductive component, the metal is preferably protruded from the surface 16a of the anodized film 16 by 10nm to 1000nm, more preferably by 50nm to 500nm, from the surface 16a of the anodized film 16 because the pressure-bonding property with the adherend such as a wiring substrate becomes good. That is, the protrusion amount of the protrusion 20a from the surface 16a is preferably 10nm to 1000nm, more preferably 50nm to 500nm.

[0159] When the height of the protruding portion 20 a of the conducting path 20 is strictly controlled, it is preferred that after the metal is filled in the through hole 17 , the anodized film 16 and the end of the conducting path 20 are processed to be flush with each other, and then the anodized film is selectively removed.

[0160] Furthermore, after the metal filling or after the metal protrusion step, a heat treatment may be performed for the purpose of alleviating deformation in the conducting path 20 caused by the metal filling.

[0161] From the viewpoint of suppressing metal oxidation, the heat treatment is preferably performed in a reducing atmosphere, specifically, preferably at an oxygen concentration of 20 Pa or less, and more preferably in a vacuum. Here, vacuum refers to a spatial state in which at least one of gas density and gas pressure is lower than atmospheric pressure.

[0162] Furthermore, for the purpose of correction, it is preferable to perform the heat treatment while applying stress to the anodized film 16 .

[0163] In order to suppress the convergence of the protrusions due to the surface tension of water during drying, supercritical drying is preferably performed. For supercritical drying, for example, a supercritical cleaning drying device (SCRD6, manufactured by Rexxam Co., Ltd.) or the like can be used.

[0164] By providing the support body 24 on the anodized film 16 , damage to the anodized film 16 can be suppressed compared to handling the anodized film 16 alone, and handling becomes easier.

[0165] Here, the operation refers to holding the anodized film 16, and moving the anodized film 16 such as transferring, conveying, and transporting the anodized film 16. Easy operation means that when the anodized film 16 is held and when the anodized film 16 is moved, damage to the anodized film 16 can be suppressed. Due to the easy operation, for example, the metal to be filled is made to protrude more than the surface 16a of the anodized film 16, but damage to the metal can be suppressed.

[0166] like Fig.14As shown in FIG. 1 , since the filled metal protrudes further than the surface 16a of the anodized film 16, it is preferred to protect the protruding metal, that is, the protruding portion 20a of the conductive path 20. Fig.15 As shown, a resin layer 26 for embedding the protrusion 20a of the conductive path 20 is preferably formed on the surface 16a of the anodized film 16. The step of providing the resin layer 26 is referred to as a resin layer forming step. The method for producing a metal-filled microstructure may include a resin layer forming step.

[0167] The resin layer 26 protects the protruding portion 20a of the conductive path 20, and can further improve the transportability of the metal-filled microstructure, making the handling easier. The resin layer 26 has adhesiveness and imparts adhesion.

[0168] The resin layer 26 can be formed using, for example, a conventionally known surface protection tape sticking device and a laminator. By providing the resin layer 26, the transportability of the metal-filled microstructure can be improved.

[0169] [Resin layer forming step]

[0170] Specifically, the resin material constituting the resin layer 26 includes, for example, ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins and cellulose resins, but from the viewpoint of transportability and ease of use as an anisotropic conductive component, the resin layer is preferably a peelable film with an adhesive layer, and more preferably a peelable film with an adhesive layer whose adhesiveness is weakened by heat treatment or ultraviolet exposure treatment.

[0171] The film with the adhesive layer is not particularly limited, and examples thereof include a heat-peelable resin layer and an ultraviolet (UV)-peelable resin layer.

[0172] Here, the heat-peelable resin layer has adhesive strength at room temperature and can be easily peeled off only by heating, and therefore, expandable microcapsules and the like are mainly used.

[0173] Specific examples of the adhesive constituting the adhesive layer include rubber adhesives, acrylic adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and styrene-diene block copolymer adhesives.

[0174] Furthermore, the UV peelable resin layer has a UV curable adhesive layer, and loses its adhesive force by curing, thereby becoming peelable.

[0175] Examples of the UV curable adhesive layer include polymers having carbon-carbon double bonds introduced into the polymer side chains, main chains, or main chain terminals in the base polymer. As the base polymer having carbon-carbon double bonds, an acrylic polymer is preferably used as the basic skeleton.

[0176] Furthermore, the acrylic polymer may contain a polyfunctional monomer or the like as a copolymerizable monomer component, if necessary, for crosslinking.

[0177] The base polymer having a carbon-carbon double bond can be used alone, or a UV curable monomer or oligomer can be blended.

[0178] Regarding the UV-curable adhesive layer, in order to cure by UV irradiation, it is preferred to use a photopolymerization initiator at the same time. Examples of the photopolymerization initiator include benzoin ether compounds; ketal compounds; aromatic sulfonyl chloride compounds; photosensitive oxime compounds; benzophenone compounds; thioxanthone compounds; camphorquinone; halogenated ketones; acylphosphine oxides; acylphosphonates, etc.

[0179] Examples of commercially available products of the heat-peelable resin layer include Intellimer (registered trademark) tapes (NITTA Corporation); Somatac 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, etc. Riva Alpha series (registered trademark) (NITTO DENKOCORPORATION.manufactured); etc.

[0180] Commercially available products of the UV peeling resin layer include, for example, ELEPH HOLDER [registered trademark] (manufactured by NITTO DENKO CORPORATION), such as ELP DU-300, ELP DU-2385KS, ELP DU-2187G, ELP NBD-3190K, and ELP UE-2091J; Adwill D-210, Adwill D-203, Adwill D-202, Adwill D-175, and Adwill D-675 (all manufactured by Lintec Corporation); SUMILITE [registered trademark] FLS N8000 series (manufactured by Sumitomo Bakelite Co., Ltd.); UC353EP-110 (manufactured by FURUKAWA ELECTRIC CO., LTD.); and other cutting tapes. In addition, as commercially available products of the UV peeling resin layer, for example, ELP RF-7232DB, ELP UB-5133D (all manufactured by NITTO DENKO CORPORATION); SP-575B-150, SP-541B-205, SP-537T-160, SP-537T-230 (all manufactured by FURUKAWA ELECTRIC CO., LTD.); and other back grinding belts can be used.

[0181] The film with an adhesive layer can be attached using a known surface protection tape attaching device and a laminator.

[0182] As a method for forming the resin layer 26, in addition to the above-mentioned method, there can be cited a method in which, for example, a resin composition containing an antioxidant material, a polymer material, a solvent (such as methyl ethyl ketone, etc.) described later is applied to the surface and back side of the anodized film 16 and the protruding portion of the conductive path, and the mixture is dried and calcined as needed.

[0183] The coating method of the resin composition is not particularly limited, and conventionally known coating methods such as gravure coating, reverse coating, die coating, blade coating, roll coating, air knife coating, screen coating, rod coating, and curtain coating can be used.

[0184] The drying method after coating is not particularly limited, and examples thereof include heating at 0°C to 100°C for a few seconds to several tens of minutes in the atmosphere, and heating at 0°C to 80°C for a dozen minutes to several hours under reduced pressure.

[0185] Furthermore, the calcination method after drying varies depending on the polymer material used and is not particularly limited. However, when a polyimide resin is used, for example, a treatment of heating at a temperature of 160° C. to 240° C. for 2 minutes to 60 minutes can be mentioned, and when an epoxy resin is used, for example, a treatment of heating at a temperature of 30° C. to 80° C. for 2 minutes to 60 minutes can be mentioned.

[0186] Next, Fig.15 The support body 24 shown is removed from the anodized film 16. In this case, the support body 24 is removed from the anodized film 16 starting from the resin substrate 22.

[0187] Then, if Fig.16 As shown, a release layer 27 is stacked on the surface 26a of the resin layer 26. The release layer 27 is a layer formed by stacking a support layer 28 and a release agent 29. The release agent 29 is in contact with the resin layer 26. For example, by heating to a predetermined temperature, the adhesive force of the release agent 29 is weakened, and the release layer 27 can be removed.

[0188] As the release agent 29 , for example, REVALPHA (registered trademark) manufactured by NITTO DENKO CORPORATION, SOMATAC (registered trademark) manufactured by SOMAR Corporation, or the like can be used.

[0189] Next, a support member 31 is mounted on the release layer 27 using a double-sided adhesive 30. The support member 31 is arranged to face the support layer 28. The support member 31 has the same outer shape as the anodized film 16. The support member 31 plays the role of a support body in the subsequent steps. By mounting the support member 31, the operability is improved.

[0190] The structure of the double-sided adhesive 30 is not particularly limited as long as it can bond the support layer 28 of the release layer 27 and the support member 31 , and for example, double-sided REVALPHA (registered trademark) manufactured by NITTO DENKO CORPORATION can be used.

[0191] The support member 31 supports the anodized film 16 and is composed of, for example, a silicon substrate. As the support member 31, for example, SiC, SiN, GaN, and alumina (Al2O3) can be used in addition to the silicon substrate. 2 O 3 ) and other ceramic substrates, glass substrates, fiber-reinforced plastic substrates, and metal substrates. Fiber-reinforced plastic substrates also include FR-4 (Flame Retardant Type 4) substrates used as printed circuit boards.

[0192] Next, the back surface 16b of the anodized film 16 is polished. In the polishing of the back surface 16b of the anodized film 16, the back surface 16b of the anodized film 16 and the end surface (not shown) of the conductive path 20 are flattened to be flush with each other. The polishing of the back surface 16b of the anodized film 16 is similar to the polishing of the back surface 16b of the anodized film 16. Fig.13 The surface smoothing treatment process performed on the surface 16a of the anodized film 16 shown is the same, so the detailed description thereof is omitted.

[0193] As described above, after the surface 16a of the anodized film 16 having the plurality of conductive paths 20 is subjected to a surface smoothing treatment process, the back surface 16b of the anodized film 16 having the plurality of conductive paths 20 is subjected to a surface smoothing treatment process, but the surface smoothing treatment process need only be applied to at least one surface.

[0194] For example, the reflectance of each of the surface 16a and the back surface 16b of the anodized film 16 is measured using a sensor (not shown). If the reflectance value is within a preset range, polishing is not performed and the next step can be transferred.

[0195] Then, if Fig.17 As shown, a portion of the anodized film 16 and the frame portion 15d is removed in the thickness direction Dt so that the metal filled above protrudes further than the back surface 16b of the anodized film 16. That is, the conductive path 20 protrudes from the back surface 16b of the anodized film 16. The portion where the conductive path 20 protrudes from the back surface 16b of the anodized film 16 is referred to as a protruding portion 20b.

[0196] The process of making the filled metal protrude further than the back surface 16 b of the anodized film 16 is the same as the above-mentioned metal protruding process, and thus a detailed description thereof is omitted.

[0197] Then, if Fig.18 As shown, a resin layer 26 is formed on the back surface 166 of the anodized film 16 to bury the protruding portion 20b of the conductive path 20 on the back surface 16b of the anodized film 16. Fig.18 The metal-filled microstructure 32 is shown.

[0198] In addition, the method of forming the resin layer 26 in which the protruding portion 20 b of the conducting path 20 is embedded is the same as the above-mentioned resin layer forming step, and thus the detailed description thereof is omitted.

[0199] like Fig.18 As shown in FIG. 1 , in a state where the resin layer 26 is formed on both sides of the anodized film 16, the frame portion 15d remains at the outer edge of the anodized film 16. The frame portion 15d remaining at the outer edge can be removed by a physical method such as dissolution or grinding. Fig.19As shown, a metal-filled microstructure 32 of the anodized film 16 alone can be obtained. In addition, if the valve metal component 15 can be removed without damaging the anodized film 16, etc., it is not limited to dissolution. Removing the valve metal component 15 such as the aluminum substrate is called a valve metal component removal process. The valve metal component removal process will be described later.

[0200] If the metal-filled microstructure 32 is in the shape of a disk, for example, the metal-filled microstructure 32 can be transported using a device used for transporting semiconductor wafers, and handling of the metal-filled microstructure 32 does not require a special device.

[0201] 〔Valve metal parts removal process〕

[0202] Regarding the treatment liquid for dissolving the valve metal component 15, in the case of an aluminum substrate, it is preferred to use a treatment liquid that does not easily dissolve the aluminum anodized film 16 and easily dissolves aluminum in the dissolution of the aluminum substrate. The dissolution rate of 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 of the anodized 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.

[0203] Specifically, the treatment liquid preferably contains at least one metal compound having a lower ionization tendency than aluminum and has a pH (hydrogen ion index) of 4 or less or 8 or more. The pH is more preferably 3 or less or 9 or more, and even more preferably 2 or less or 10 or more.

[0204] As such a treatment liquid, a treatment liquid preferably is based on an acid or alkaline aqueous solution, for example, a treatment liquid prepared by mixing compounds of manganese, zinc, chromium, iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper, mercury, silver, palladium, platinum, gold (such as chloroplatinic acid), their fluorides, their chlorides, etc.

[0205] Among them, an acidic aqueous solution base is preferred, and a mixed chloride is preferred.

[0206] In particular, from the viewpoint of the treatment range, a treatment liquid in which mercuric chloride is mixed in a hydrochloric acid aqueous solution (hydrochloric acid / mercuric chloride) or a treatment liquid in which cupric chloride is mixed in a hydrochloric acid aqueous solution (hydrochloric acid / cupric chloride) is preferred.

[0207] The composition of the treatment liquid is not particularly limited, and for example, a bromine / methanol mixture, a bromine / ethanol mixture, aqua regia, etc. can be used.

[0208] Furthermore, the acid or alkali concentration of the treatment liquid is preferably 0.01 to 10 mol / L, more preferably 0.05 to 5 mol / L.

[0209] The treatment temperature using such a treatment liquid is preferably -10°C to 80°C, more preferably 0°C to 60°C.

[0210] Furthermore, the dissolution of the valve metal component 15 is performed by bringing the valve metal component 15 into contact with the treatment liquid after the metal removal step. The contact method is not particularly limited, and examples thereof include an immersion method and a spray method. Among them, an immersion method is preferred. The contact time at this time is preferably 10 seconds to 5 hours, and more preferably 1 minute to 3 hours.

[0211] [Second Example of Method for Producing Metal-Filled Microstructure]

[0212] Figure 20 to Figure 24 2 is a schematic cross-sectional view showing a second example of a method for manufacturing a metal-filled microstructure according to an embodiment of the present invention in order of steps. Figure 20 to Figure 24 In, with Figure 6 The same components as shown are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0213] The second example of the method for manufacturing a metal-filled microstructure is different from the first example of the method for manufacturing a metal-filled microstructure in that the mask 12 is not formed only on the outer edge 11b of the surface 11a of the valve metal member 11 (see Figure 4 ), but the mask 13 having the opening 13a is arranged on the outer edge 11b of the surface 11a of the valve metal member 11, and except for this, in the same manner as the first example of the method for manufacturing the metal-filled microstructure, it is possible to obtain Figure 6 The metal filling member 21 and Fig.18 and Fig.19 The metal-filled microstructure 32 is shown.

[0214] like Fig. 20 As shown in FIG. 1 , a mask 13 having an opening 13a is disposed on the surface 11a of the valve metal member 11. Fig.21 As shown in FIG. 1 , a mask 13 is provided on the outer edge 11b of the surface 11a of the valve metal member 11. At this time, on the surface 11a of the valve metal member 11, a region 11c corresponding to the opening 13a of the mask 13 is an anodized film 11d (refer to FIG. Fig. 22 ) formation area.

[0215] Next, an anodic oxide film forming step is performed in which an anodic oxidation treatment is performed using the valve metal component 11 as an electrode, and the region 11c of the valve metal component 11 surrounded by the mask 13 is formed as an anodic oxide film. The anodic oxide film forming step is the same as the first example of the method for manufacturing the metal-filled microstructure, and therefore a detailed description thereof is omitted. In the anodic oxide film forming step, an anodic oxide film 11d is formed in the region 11c, but the valve metal component 11 below the mask 13 is not anodic oxidized.

[0216] After anodizing, Fig.23 As shown in FIG. 1 , the mask 13 is separated from the surface 11a of the valve metal member 11. Next, Fig.23 The anodized film 11d shown removes the barrier layer, such as Fig.24 As shown, a plurality of through holes 17 extending in the thickness direction Dt are formed in the anodized film 11d, thereby obtaining an anodized film 16 composed of the anodized film 11d.

[0217] Next, a filling process is performed, in which Fig.24 The structure 18 shown is formed by filling metal in the plurality of through holes 17 of the anodized film 16. The structure 18 is filled with metal in the plurality of through holes 17 of the anodized film 16 and beyond the surface 16a of the anodized film 16, thereby forming a Figure 6 As shown, a metal layer 19 is formed. Figure 6 The metal-filled member 21 is shown. The method for forming the metal layer 19 is the same as the first example of the method for producing the metal-filled microstructure, and therefore, a detailed description thereof is omitted.

[0218] [Third Example of Method for Producing Metal-Filled Microstructure]

[0219] Figure 25 to Figure 29 1 is a schematic cross-sectional view showing a third example of a filled microstructure according to an embodiment of the present invention in order of steps. Figure 25 to Figure 29 In, with Figure 6 The same components as shown are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0220] The third example of the method for manufacturing a metal-filled microstructure is different from the first example of the method for manufacturing a metal-filled microstructure in that the entire surface 11a of the valve metal part is anodized and the anodized film is removed to form the frame portion. In addition, in the same manner as the first example of the method for manufacturing a metal-filled microstructure, a valve metal part can be obtained. Figure 6 The metal filling member 21 and Fig.18 and Fig.19 The metal-filled microstructure 32 is shown.

[0221] In the third example of the method for manufacturing a metal-filled microstructure, a valve metal component 11 is prepared in the same manner as in the first example of the method for manufacturing a metal-filled microstructure (see Figure 1 ). Next, the entire surface 11a of the valve metal member 11 is anodized, leaving the bottom 11e of the valve metal member 11 (refer to Figure 3 ) to form an anodic oxide film 11d (reference Figure 3 ). In addition, the barrier layer is removed from the anodized film 11d, as shown in FIG. Fig.25 As shown, a plurality of through holes 17 extending in the thickness direction Dt are formed in the anodized film 11d, thereby obtaining an anodized film 16 composed of an anodized film. Below the anodized film 16, a portion of the valve metal member 11 (see Figure 3 ) of the bottom 11e (reference Figure 3 ), the bottom 11e is the bottom 15e of the valve metal component 15 (reference Fig.25 The thickness of the anodized film 16 is preferably H A Less than 200μm. If the thickness H A If the thickness is less than 200 μm, it can be considered that the anodized film 16 and the valve metal member 15 are on the same surface.

[0222] Then, if Fig.26 As shown, on the surface 16a of the anodized film 16, in addition to the outer edge 16e of the anodized film 16, a mask 14 is also arranged. In this state, a liquid having the property of dissolving the anodized film 16 and not dissolving the valve metal component 15 is used to dissolve the outer edge 16e of the anodized film 16. As a result, as Fig. 27 As shown, the bottom 15e of the valve metal member 15 is exposed.

[0223] In addition, the mask 14 is not particularly limited as long as it is insoluble in a liquid having the property of dissolving the anodized film 16 and not dissolving the valve metal component 15, and for example, a resist film is used. The resist film used for the mask 14 can be formed by forming the resist film on the entire surface 16a of the anodized film 16 and then removing the resist film on the outer edge 16e of the anodized film 16 by photolithography.

[0224] As the liquid having the property of dissolving the anodized film 16 and not dissolving the valve metal member 15, a liquid that dissolves aluminum oxide (Al 2 O 3 ) is an acidic aqueous solution or an alkaline aqueous solution. Specifically, for example, an aqueous hydrochloric acid solution containing cupric chloride is used.

[0225] Then, if Fig.28As shown, the mask 14 is removed from the surface 16a of the anodized film 16. Thus, a structure 18 including the valve metal member 15 and the anodized film 16 is obtained.

[0226] The difference between the surface 16a of the anodized film 16 and the upper surface of the frame portion 15d, that is, the thickness H of the anodized film 16 A Therefore, the surface 16a of the anodized film 16 is substantially flush with the upper surface of the frame portion 15d.

[0227] In addition, if the mask 14 is a resist film, for example, it can be removed by ashing.

[0228] Next, a filling process is performed, in which Fig.28 The structure 18 shown in the figure is filled with metal in the plurality of through holes 17 of the anodized film 16. The structure 18 is filled with metal in the plurality of through holes 17 of the anodized film 16 beyond the surface 16a of the anodized film 16, thereby Fig.29 The metal layer 19a is formed as shown. Thus, the metal filling component 21 is obtained. At this time, the conductive path 20 having conductivity is formed by forming the metal layer 19a, thereby forming the metal filling component 21. The method for forming the metal layer 19a is the same as the method for forming the metal layer 19 in the first example of the method for manufacturing the metal-filled microstructure, so its detailed description is omitted.

[0229] In addition, the mask 14 is disposed and the outer edge 16e of the anodized film 16 is dissolved, but the present invention is not limited thereto, and the outer edge 16e of the anodized film 16 may be physically cut by grinding or laser. Furthermore, a liquid having the property of dissolving the anodized film but not dissolving the valve metal part may be sprayed onto the outer edge 16e of the anodized film 16 by an inkjet method, so as to selectively dissolve the outer edge 16e of the anodized film 16.

[0230] [Fourth Example of Method for Producing Metal-Filled Microstructure]

[0231] Figure 30 to Figure 34 1 is a schematic cross-sectional view showing a fourth example of a method for manufacturing a metal-filled microstructure according to an embodiment of the present invention in order of steps. Figure 30 to Figure 34 , for Figure 6 The same components as shown are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0232] The fourth example of the method for manufacturing a metal-filled microstructure is different from the first example of the method for manufacturing a metal-filled microstructure in that the valve metal component 11 is anodized using an electrode body 60 having a conductive layer 62 partially formed on a surface 61a of an insulating support body 61, and other than that, a valve metal component 11 can be obtained in the same manner as the first example of the method for manufacturing a metal-filled microstructure. Figure 6 The metal filling member 21 and Fig.18 and Fig.19 The metal-filled microstructure 32 is shown.

[0233] In the fourth example of the method for manufacturing a metal-filled microstructure, Fig.30 As shown, first, an electrode body 60 is prepared in which a conductive layer 62 having conductivity is partially formed on a surface 61a of a rectangular insulating support body 61. The electrode body 60 is used as an electrode during anodizing treatment.

[0234] The conductive layer 62 forms a resist layer 63 on the surface 61a of the insulating support 61, and the resist layer 63 is partially removed by patterning using, for example, photolithography. Next, a seed layer (not shown) is formed on the resist layer 63, for example, and the conductive layer 62 is formed by plating. When the conductive layer 62 is formed, the surfaces of the resist layer 63 and the conductive layer 62 are flattened by a flattening treatment. In addition, the conductive layer 62 is formed by plating, but the method for forming the conductive layer 62 is not particularly limited.

[0235] Then, if Fig.31 As shown in FIG. 1 , a valve metal member 11 is provided with a conductive layer 62 covering the electrode body 60. The valve metal member 11 is formed by an anodic oxide film 16 (refer to FIG. 1 ) of the metal filler member 21. Fig.33 ) that is, the thickness of the anodized film, or the thickness of the metal-filled microstructure 32 obtained in the end (reference Fig.34 ) The size and thickness are appropriately determined by the thickness of the anodized film 16, the processing equipment, etc. The valve metal member 11 is, for example, a rectangular plate.

[0236] As the valve metal member 11 , an aluminum substrate is used as described above.

[0237] In addition, as the valve metal component 11, for example, an aluminum substrate can be prepared, but the valve metal component 11 can also be formed on the electrode body 60. In this case, in the valve metal layer forming step, for example, an aluminum substrate is formed as the valve metal component 11 on the surface 62a of the conductive layer 62 and the surface 63a of the resist layer 63 by, for example, a vapor deposition method.

[0238] Next, an anodic oxide film forming step is performed in which an anodic oxide treatment is performed using the conductive layer 62 as an electrode, and the valve metal member 11 in the region on the conductive layer 62 of the valve metal member 3 is formed into an anodic oxide film. The anodic oxide film is an insulating base material. The anodic oxide film 11d is formed by performing an anodic oxide treatment on the valve metal member 11.

[0239] In the anodized film forming step, the conductive layer 62 is used as a cathode electrode and the valve metal component 11 is used as an anode electrode to perform an anodizing treatment. As a result, the valve metal component 11 on the conductive layer 62 is anodized. Fig.32 As shown, an anodic oxide film 11d is formed in the region 15c of the valve metal member 15. In the anodizing process, for example, if an extraction electrode is provided on the conductive layer 62, a direct current is applied to the conductive layer 62 by the extraction electrode.

[0240] In the anodizing treatment, as described above, the conductive layer 62 of the electrode body 60 is used as an electrode, and the valve metal member 11 (refer to Fig.31 ) becomes the region 11c where the anodized film 11d is formed (reference Fig.31 ), the valve metal component 11 on the resist layer 63 (reference Fig.31 ) is the outer edge 15b of the valve metal component 15, which becomes the frame portion 15d.

[0241] The anodized film 11d is formed in the above-mentioned region 11c, but the valve metal member 11 on the resist layer 63 is not anodized. In this way, the valve metal member 11 is not entirely formed into the anodized film 11d, and the region of the valve metal member 11 is retained even after the anodizing treatment. Thus, the frame portion 15d of the valve metal member 15 composed of the valve metal member 11 is arranged on the outer edge 15b of the valve metal member 15. The anodized film 11d is formed in the region 15c surrounded by the frame portion 15d (see Fig.32 ) as the anodized film 16.

[0242] During the anodizing treatment, the entire valve metal member 11 on the conductive layer 62 can be formed into the anodized film 11d. However, by adjusting the anodizing treatment time, etc., a portion of the valve metal member 11 on the conductive layer 62 can be formed into the anodized film 11d. Fig.32 In the embodiment, the valve metal member 15 exists between the conductive layer 62 and the anodized film 16 which is an anodized film.

[0243] In addition, since the valve metal member 11 is made of aluminum, an anodic oxide film 11d is formed as an oxide film. The anodic oxide film 11d is made of Al. 2 O 3 Membrane composition.

[0244] The anodized film 11d has a plurality of micropores when it is formed. However, among the plurality of micropores, there are also micropores that do not penetrate in the thickness direction Dt. In addition, there is a barrier layer (not shown) at the bottom of the micropores. Therefore, Fig.32 The anodized film 11d shown removes the barrier layer, such as Fig.33 As shown, a plurality of through holes 17 extending in the thickness direction Dt are formed in the anodized film 11d, thereby obtaining an anodized film 16 composed of the anodized film 11d.

[0245] Through the above steps, the anodic oxide film 16 (anodic oxide film) having a plurality of pores (through holes 17) is formed in the region 15c surrounded by the frame portion 15d disposed on the outer edge 15b of the valve metal member 15, thereby obtaining a structure 18 having the valve metal member 15 and the anodic oxide film 16 (anodic oxide film). For example, Fig.33 As shown, an anodic oxide film 16 (anodic oxide film) is formed on the surface 15a of the valve metal member 15, and a frame portion 15d exists around the anodic oxide film 16. Also, although not shown, the surface 16a of the anodic oxide film 16 and the upper surface of the frame portion 15d are substantially on the same plane.

[0246] As mentioned above, Fig.32 The anodized film forming process shown in FIG. Fig.33 The step of forming the plurality of through holes 17 extending in the thickness direction Dt is a step of obtaining the structure 18 .

[0247] Then, if Fig.34 As shown, a filling process is performed in which a metal is filled in a plurality of through holes 17 of anodized film 16 of structure 18. Metal is filled in a plurality of through holes 17 of anodized film 16 of structure 18 beyond surface 16a of anodized film 16, thereby forming the above-mentioned metal layer 19. Thus, metal-filled component 21 is obtained. At this time, conductive path 20 is formed by forming metal layer 19. The method for forming metal layer 19 is the same as the first example of the method for manufacturing metal-filled microstructure, and therefore its detailed description is omitted.

[0248] In the filling step, metal is filled inside the plurality of through holes 17 of the anodized film 16, and Fig.34 As shown, a metal layer 19 is formed on the surface of the structure 18, that is, on the frame portion 15d of the metal filling member 21 and on the surface 16a of the anodized film 16, so that the metal is filled in the plurality of through holes 17. In this case, in the metal layer 19, as described above, the thickness δ (refer to Figure 2 ) is set to 2μm~100μm.

[0249] In addition, for example, by extending the plating time, the thickness δ of the metal layer 19 can be increased. In the filling step, the metal is filled beyond the surface 16a of the anodized film 16, so that the metal layer 19 is also formed on the frame portion 15d.

[0250] An example of the structure of the metal-filled microstructure will be described below.

[0251] [An example of a metal-filled microstructure]

[0252] Fig.35 is a plan view showing an example of the structure of a metal-filled microstructure according to an embodiment of the present invention, Fig.36 This is a schematic cross-sectional view showing an example of the structure of the metal-filled microstructure according to the embodiment of the present invention. Fig.36 yes Fig.35 Section view of section line IB-IB.

[0253] As mentioned above, Fig.35 and Fig.36 The metal-filled microstructure 32 shown has an anodized film 16 as an insulating substrate, a through hole 17 penetrating the anodized film 16 in the thickness direction Dt, and a plurality of conductive paths 20 composed of metal filled in the through hole 17. The plurality of conductive paths 20 are provided in a state of being electrically insulated from each other. In addition, for example, a resin layer 26 is provided on the surface 16a and the back surface 16b of the anodized film 16.

[0254] Here, “a state in which the conduction paths 20 existing inside the anodized film 16 are electrically insulated from each other” means a state in which the conduction properties between the conduction paths 20 existing inside the anodized film 16 are sufficiently low.

[0255] The metal-filled fine structure 32 is a member that electrically insulates the conduction paths 20 from each other, has sufficiently low conductivity in a direction x orthogonal to the thickness direction Dt of the anodized film 16, has conductivity in the thickness direction Dt, and exhibits anisotropic conductivity. The metal-filled fine structure 32 is arranged so that the thickness direction Dt coincides with, for example, the stacking direction of the electronic element described later.

[0256] like Fig.35 and Fig.36 As shown, the conducting paths 20 are provided penetrating the anodized film 16 in the thickness direction Dt in a state where the conducting paths 20 are electrically insulated from each other.

[0257] The thickness h of the metal-filled fine structure 32 is, for example, 40 μm or less. Furthermore, the TTV (Total Thickness Variation) of the metal-filled fine structure 32 is preferably 10 μm or less. Since the surface 16a and the back surface 16b of the anodized film 16 are ground, the thickness is thicker than the thickness h of the metal-filled fine structure 32, for example, more than 60 μm, but is preferably about 40 μm from the viewpoint of brittleness.

[0258] Here, the thickness h of the metal-filled microstructure 32 and the thickness of the anodized film 16 are obtained by cutting the metal-filled microstructure 32 and the anodized film 16 in the thickness direction using a focused ion beam (FIB), observing their cross-sections with a field emission scanning electron microscope at a magnification of 200,000 times to obtain the contour shapes of the metal-filled microstructure 32 and the anodized film 16, and measuring the average value of 10 points in the area equivalent to the thickness h.

[0259] The TTV (Total Thickness Variation) of the metal-filled microstructure 32 is a value obtained by cutting the metal-filled microstructure 32 together with the support member 31 by dicing and observing the cross-sectional shape of the metal-filled microstructure 32 .

[0260] The metal-filled fine structure 32 can be used as an anisotropic conductive component showing anisotropic conductivity, for example. In this case, semiconductor elements and semiconductor elements are joined via the metal-filled fine structure 32, so that an electronic element in which the semiconductor elements and semiconductor elements are electrically connected can be obtained. In the electronic element, the metal-filled fine structure 32 plays the role of TSV (Through Silicon Via).

[0261] In addition, it is also possible to use the metal-filled fine structure 32 to electrically connect three or more semiconductor elements as an electronic component. By using the metal-filled fine structure 32, three-dimensional mounting can be performed. In addition, the number of semiconductor elements to be joined is not particularly limited and is appropriately determined according to the function of the electronic component and the performance required of the electronic component.

[0262] Thermocompression bonding can be used for bonding with electronic components. If bonding is performed in a reducing atmosphere, the metal electrode and the protrusion can be easily bonded at a temperature of 250° C. or less, thereby reducing the thermal influence on the device.

[0263] By using the metal-filled microstructure 32, the size of the electronic component can be reduced, and the mounting area can be reduced. In addition, by reducing the thickness of the metal-filled microstructure 32, the wiring length between semiconductor components can be shortened, and signal delay can be suppressed and the processing speed of the electronic component can be increased. By shortening the wiring length between semiconductor components, power consumption can also be suppressed.

[0264] As described above, the metal-filled microstructure 32 has high shape accuracy because the anodized film 16 and the conductive path 20 are polished to be on the same surface 16a of the anodized film 16. As well, as described above, the height of the protrusion 20a of the conductive path 20 can be strictly controlled, so the reliability of the electrical connection between semiconductor elements is excellent.

[0265] Furthermore, since the metal-filled microstructure 32 is densely filled with metal, its thermal conductivity is higher than that of resin materials. The thermal conductivity in the vertical direction between the connected electrodes and the semiconductor elements and the thermal diffusion in the plane direction are large, so it is particularly useful for components that need heat dissipation. In addition to the above-mentioned semiconductor elements, the metal-filled microstructure 32 can also be used for heat dissipation of metal base substrates, etc., and is also effective for connecting heat sinks. In addition, it is very effective for the connection of memories, etc., where heat generation caused by multi-layer connection becomes a problem.

[0266] As semiconductor elements, for example, logic integrated circuits such as ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), and ASSP (Application Specific Standard Product) can be cited. Also, for example, microprocessors such as CPU (Central Processing Unit) and GPU (Graphics Processing Unit) can be cited. Also, for example, memories such as DRAM (Dynamic Random Access Memory), HMC (Hybrid Memory Cube), MRAM (Magnetoresistive Random Access Memory), PCM (Phase-Change Memory), ReRAM (Resistance Random Access Memory), FeRAM (Ferroelectric Random Access Memory), and flash memory can be cited. In addition, examples include analog integrated circuits such as LEDs (Light Emitting Diodes), power devices, DC (Direct Current)-DC (Direct Current) converters, and insulated gate bipolar transistors (IGBTs). In addition, examples include MEMS (Micro Electro Mechanical Systems) such as acceleration sensors, pressure sensors, vibrators, and gyro sensors.In addition, for example, wireless components such as GPS (Global Positioning System), FM (Frequency Modulation), NFC (Nearfield communication), RFEM (RF Expansion Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), discrete components, CMOS (Complementary Metal Oxide Semiconductor), CMOS image sensors, camera modules, passive devices, SAW (Surface Acoustic Wave) filters, RF (Radio Frequency) filters, IPD (Integrated Passive Devices), etc. can be cited.

[0267] Furthermore, the semiconductor element may have an element region, which is an area where various elements constituting circuits for functioning as electronic elements are formed. In the element region, for example, there are the following areas: an area where memory circuits such as flash memory are formed, a logic circuit such as a microprocessor and FPGA (field-programmable gate array), and an area where communication modules and wiring such as wireless tags are formed. In addition, MEMS (Micro Electro Mechanical Systems) may also be formed in the element region. MEMS are, for example, sensors, actuators, and antennas. Among the sensors, for example, various sensors such as acceleration sensors, sound sensors, and optical sensors are included. As long as the optical sensor can detect light, it is not particularly limited. For example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor may be used.

[0268] The semiconductor element is appropriately selected according to the function to be realized in the electronic element. For example, in the electronic element, a semiconductor element having a logic circuit and a semiconductor element having a memory circuit can be combined. In addition, as a combination of semiconductor elements in the electronic element, a sensor, an actuator, an antenna, etc., can be combined with a memory circuit and a logic circuit.

[0269] The semiconductor element is made of, for example, silicon, but is not limited thereto, and may be made of silicon carbide, germanium, gallium arsenide, gallium nitride, or the like.

[0270] Furthermore, in addition to the semiconductor element, the metal-filled fine structure 32 can be used to electrically connect two wiring layers.

[0271] Hereinafter, the structure of the metal-filled fine-structure body 32 will be described in more detail.

[0272] 〔Anodic oxide film〕

[0273] The anodized film 16 functions as an insulating substrate. The spacing between each conductive path in the anodized film 16 is preferably 5nm to 800nm, more preferably 10nm to 200nm, and further preferably 20nm to 60nm. If the spacing between each conductive path in the anodized film 16 is within this range, the anodized film 16 fully functions as an insulating partition.

[0274] Here, the interval between each conductive path refers to the width w between adjacent conductive paths and refers to the average value of the width between adjacent conductive paths measured at 10 points by observing the cross section of the metal-filled microstructure 32 at a magnification of 200,000 times using a field emission scanning electron microscope.

[0275] <Average pore diameter>

[0276] The average diameter of the pores, that is, the average diameter d of the through-holes 17 (refer to Fig.35 , Fig.36 ) is 1 μm or less, preferably 5 to 500 nm, more preferably 20 to 400 nm, further preferably 40 to 200 nm, and most preferably 50 to 100 nm. The average diameter d of the through hole 17 is 1 μm or less. If it is within the above range, when an electrical signal flows through the resulting conductive path 20, a sufficient response can be obtained, so it can be more preferably used as a connector for testing electronic parts. In addition, if the average diameter d of the through hole 17 is 1 μm or less, the metal layer 19 can be easily removed (refer to Figure 6 ).

[0277] Regarding the average diameter d of the through hole 17, a photographic image is obtained by photographing the surface of the anodized film 16 from directly above at a magnification of 100 to 10,000 times using a scanning electron microscope. At least 20 through holes connected in a ring shape are extracted from the photographic image, and their diameters are measured and set as the opening diameter. The average value of these open U diameters is calculated as the average diameter of the through holes.

[0278] In addition, the magnification can be appropriately selected within the above range to obtain a photographic image capable of extracting more than 20 through-holes. In addition, regarding the opening diameter, the maximum value of the distance between the ends of the through-hole portion is measured. That is, since the shape of the opening portion of the through-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 through-hole portion is set as the opening diameter. Therefore, in the case of a through-hole having a shape such as two or more through-holes integrated, it is also regarded as one through-hole, and the maximum value of the distance between the ends of the through-hole portion is set as the opening diameter.

[0279] 〔Conduction Path〕

[0280] As described above, the plurality of conducting paths 20 are provided in a columnar shape so as to penetrate the anodized film 16 in the thickness direction Dt and be electrically insulated from each other. The conducting paths 20 are made of metal. The conducting paths 20 may have protrusions protruding from the surface and back surface of the anodized film 16, and the protrusions of each conducting path are buried in the resin layer.

[0281] Specific examples of the metal constituting the conductive path preferably include gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), and nickel (Ni). From the viewpoint of conductivity, copper, gold, aluminum, and nickel are preferred, and copper and gold are more preferred.

[0282] <Protrusion>

[0283] The protruding portions 20 a and 20 b of the conducting path 20 are portions of the conducting path 20 protruding from the front surface 16 a and the back surface 16 b of the anodized film 16 , and are preferably protected by the resin layer 26 .

[0284] When the metal-filled microstructure 32 is used as an anisotropic conductive component, when the anisotropic conductive component is electrically connected or physically joined to an electrode by crimping or the like, the aspect ratio of the protrusion of the conductive path (height of the protrusion / diameter of the protrusion) is preferably greater than 0.5 and less than 50, more preferably 0.8 to 20, and even more preferably 1 to 10, for the reason that the insulation in the surface direction when the protrusion is flattened can be sufficiently ensured.

[0285] Furthermore, from the viewpoint of following the surface shape of the semiconductor element or semiconductor wafer to be connected, the height of the protruding portion of the conductive path is preferably 20 nm or more, and more preferably 100 nm to 500 nm.

[0286] The height of the protruding portion of the conducting path is the average value of the height of the protruding portion of the conducting path measured at 10 points by observing a cross section of the anisotropic conductive member at a magnification of 20,000 times using an electrolytic emission scanning electron microscope.

[0287] The diameter of the protruding portion of the conducting path is the average value of the diameters of the protruding portion of the conducting path measured at 10 points by observing a cross section of the anisotropic conductive member with an electrolytic emission scanning electron microscope.

[0288] <Other shapes>

[0289] The density of the conductive paths 20 is preferably 20,000 per mm. 2 More than 2 million / mm 2 More than 10 million pieces / mm 2 More than 50 million / mm is particularly preferred 2 More than 100 million pieces / mm is most preferred 2 above.

[0290] In addition, the center distance p between adjacent conductive paths 20 (refer to Fig.35 and Fig.36 ) is preferably 20 nm to 500 nm, more preferably 40 nm to 200 nm, and further preferably 50 nm to 140 nm.

[0291] 〔Resin layer〕

[0292] As described above, resin layer 26 is provided on surface 16a and back surface 16b of anodized film 16, and as described above, buries protruding portions 20a and 20b of conductive path 20. That is, resin layer 26 covers the end portions of conductive path 20 protruding from anodized film 16 and protects protruding portions 20a and 20b.

[0293] The resin layer 26 is formed by the above-mentioned resin layer forming step. The resin layer 26 imparts adhesiveness to the connection object. The resin layer 26 is preferably a resin layer that exhibits fluidity in a temperature range of 50°C to 200°C and cures at a temperature of 200°C or higher.

[0294] The resin layer 26 is formed by the above-mentioned resin layer forming step, but the composition of the resin layer shown below can also be used. The composition of the resin layer is described below. For example, the resin layer contains a polymer material and may also contain an antioxidant material.

[0295] <Polymer Materials>

[0296] The polymer material contained in the resin layer is not particularly limited, but is preferably a thermosetting resin because it can efficiently fill the gap between the semiconductor element or semiconductor wafer and the anisotropic conductive component and further improve the adhesion with the semiconductor element or semiconductor wafer.

[0297] Specific examples of the thermosetting resin include epoxy resins, phenol resins, polyimide resins, polyester resins, polyurethane resins, bismaleimide resins, melamine resins, and isocyanate resins.

[0298] Among them, polyimide resin and / or epoxy resin are preferably used because they can further improve insulation reliability and have excellent chemical resistance.

[0299] <Antioxidant Materials>

[0300] Specific examples of the antioxidant material contained in the resin layer include 1,2,3,4-tetrazole, 5-amino-1,2,3,4-tetrazole, 5-methyl-1,2,3,4-tetrazole, 1H-tetrazole-5-acetic acid, 1H-tetrazole-5-succinic acid, 1,2,3-triazole, 4-amino-1,2,3-triazole, 4,5-diamino-1,2,3-triazole, 4-carboxyl-1H-1,2,3-triazole, 4,5-dicarboxyl-1H-1,2,3-triazole, 1H-1,2,3-triazole-4-acetic acid, 4-carboxyl-5-carboxyl Methyl-1H-1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-carboxy-1,2,4-triazole, 3,5-dicarboxy-1,2,4-triazole, 1,2,4-triazole-3-acetic acid, 1H-benzotriazole, 1H-benzotriazole-5-carboxylic acid, benzofuran, 2,1,3-benzothiazole, o-phenylenediamine, m-phenylenediamine, catechol, o-aminophenol, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, melamine and derivatives thereof.

[0301] Among them, benzotriazole and its derivatives are preferred.

[0302] Examples of benzotriazole derivatives include substituted benzotriazoles having a hydroxyl group, an alkoxy group (e.g., a methoxy group, an ethoxy group, etc.), an amino group, a nitro group, an alkyl group (e.g., a methyl group, an ethyl group, and a butyl group), a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, etc.) on the benzene ring of the benzotriazole. Also, examples include naphthalenetriazole, naphthalenebistriazole, substituted naphthalenetriazoles substituted in the same manner, and substituted naphthalenebistriazoles.

[0303] Furthermore, other examples of the antioxidant material contained in the resin layer include higher fatty acids, higher fatty acid copper, phenol compounds, alkanolamines, hydroquinones, copper chelating agents, organic amines, and organic ammonium salts, which are common antioxidants.

[0304] The content of the antioxidant material contained in the resin layer is not particularly limited, but is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, relative to the total mass of the resin layer from the viewpoint of the anticorrosion effect. Also, from the perspective of obtaining an appropriate resistance in the actual bonding process, it is preferably 5.0% by mass or less, more preferably 2.5% by mass or less.

[0305] <Anti-migration materials>

[0306] The resin layer preferably contains a migration prevention material because the resin layer can capture metal ions, halogen ions, and metal ions derived from the semiconductor element and the semiconductor wafer that may be contained in the resin layer, thereby further improving insulation reliability.

[0307] As the migration preventing material, for example, an ion exchanger can be used, specifically, a mixture of a cation exchanger and an anion exchanger or only a cation exchanger can be used.

[0308] Here, the cation exchanger and the anion exchanger can be appropriately selected from, for example, inorganic ion exchangers and organic ion exchangers described below, respectively.

[0309] (Inorganic ion exchanger)

[0310] Examples of the inorganic ion exchanger include metal hydroxides represented by zirconium hydroxide.

[0311] As the types of metals, for example, iron, aluminum, tin, titanium, antimony, magnesium, beryllium, indium, chromium, bismuth, and the like are known in addition to zirconium.

[0312] Among them, zirconium metals have cation Cu 2+ 、Al 3+ In addition, iron metals also have Ag + , Cu 2+ Similarly, tin, titanium and antimony metals are cation exchangers.

[0313] On the other hand, bismuth-based metals have the ability to exchange anions Cl.

[0314] Furthermore, zirconium-based metals show anion exchange capacity depending on conditions. The same is true for aluminum-based and tin-based metals.

[0315] As other inorganic ion exchangers, there are known acid salts of polyvalent metals represented by zirconium phosphate, heteropolyacid salts represented by ammonium molybdenum phosphate, and synthetic products such as insoluble ferrocyanide.

[0316] Some of these inorganic ion exchangers are commercially available, and various grades are known under the trade name "IXE" from TOAGOSEI CO., LTD., for example.

[0317] In addition to synthetic products, inorganic ion exchanger powders such as natural products such as zeolite and montmorillonite can also be used.

[0318] (Organic ion exchanger)

[0319] Examples of the organic ion exchanger include crosslinked polystyrene having a sulfonic acid group as a cation exchanger, and further examples include crosslinked polystyrene having a carboxylic acid group, a phosphonic acid group, or a phosphinic acid group.

[0320] Furthermore, cross-linked polystyrene having a quaternary ammonium group, a quaternary phosphonium group or a tertiary sulfonium group can be mentioned as an anion exchanger.

[0321] These inorganic ion exchangers and organic ion exchangers may be appropriately selected in consideration of the types of cations and anions to be captured and the exchange capacity of the ions. Of course, inorganic ion exchangers and organic ion exchangers may be mixed and used.

[0322] Since the manufacturing process of electronic components includes a heating step, an inorganic ion exchanger is preferred.

[0323] Furthermore, for example, from the viewpoint of mechanical strength, the mixing ratio of the migration prevention material to the polymer material is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2.5% by mass or less. Furthermore, from the viewpoint of suppressing migration when bonding a semiconductor element or semiconductor wafer to an anisotropic conductive component, the migration prevention material is preferably 0.01% by mass or more.

[0324] <Inorganic fillers>

[0325] The resin layer may contain an inorganic filler.

[0326] The inorganic filler is not particularly limited and can be appropriately selected from known inorganic fillers. For example, kaolin, barium sulfate, barium titanate, silicon oxide powder, fine powdered silicon oxide, fumed silica, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, aluminum nitride, zirconium oxide, yttrium oxide, silicon carbide and silicon nitride can be mentioned.

[0327] In order to prevent the inorganic filler from entering between the conducting paths and further improve the conduction reliability, the average particle size of the inorganic filler is preferably larger than the interval between the conducting paths.

[0328] The average particle size of the inorganic filler is preferably 30 nm to 10 μm, more preferably 80 nm to 1 μm.

[0329] Here, regarding the average particle size, the primary particle size measured by a laser diffraction and scattering particle size measuring apparatus (Microtrac MT3300 manufactured by NIKKISO CO., LTD.) is defined as the average particle size.

[0330] <Curing agent>

[0331] The resin layer may contain a curing agent.

[0332] When a curing agent is contained, it is more preferable to contain a curing agent that is liquid at room temperature rather than a solid curing agent at room temperature from the viewpoint of suppressing poor bonding with the surface shape of a semiconductor element or semiconductor wafer to be connected.

[0333] Here, "solid at room temperature" means a substance that is solid at 25°C, for example, a substance having a melting point higher than 25°C.

[0334] Specific examples of the curing agent include aromatic amines such as diaminodiphenylmethane and diaminodiphenyl sulfone, aliphatic amines, imidazole derivatives such as 4-methylimidazole, dicyandiamide, tetramethylguanidine, thiourea-added amines, carboxylic anhydrides such as methylhexahydrophthalic anhydride, carboxylic acid hydrazides, carboxylic acid amides, polyphenol compounds, novolac resins, and polythiol, and a curing agent that is liquid at 25° C. can be appropriately selected from these curing agents. The curing agent may be used alone or in combination of two or more.

[0335] The resin layer may contain various additives such as a dispersant, a buffer, and a viscosity adjuster, which are generally widely added to a resin insulating film of a semiconductor package, within a range not impairing the characteristics thereof.

[0336] <Shape>

[0337] For the purpose of protecting the conductive path 20 of the metal-filled fine-structure body 32 , the thickness of the resin layer is larger than the height of the protruding portions 20 a and 20 b of the conductive path 20 and is preferably 1 μm to 5 μm.

[0338] Next, the holding step will be described.

[0339] [Maintaining process]

[0340] Fig.37 is a schematic perspective view showing an example of a container used in the holding step according to an embodiment of the present invention, Fig.38 This is a schematic cross-sectional view of an example of a storage container showing a holding step according to an embodiment of the present invention.

[0341] In the holding process, holding not only means a stationary state but also includes movement such as conveyance and is not limited to a stationary state.

[0342] As described above, the holding step is to hold the structure 18 (reference Figure 5 ) is filled with metal into a plurality of through holes 17 (pores) obtained by filling the metal (reference Figure 6 ), and then exposed to an environment with a relative humidity of 10 to 30% for more than 24 hours. Through the above-mentioned holding step, a stable insulation resistance is obtained in the oxide film (anodized film 16) having through holes (pores). If the relative humidity exceeds 40%, the insulation resistance fluctuates and a stable insulation resistance cannot be obtained.

[0343] On the other hand, maintaining the relative humidity at less than 10% requires specialized equipment and the like, and it is difficult to manage the humidity.

[0344] Furthermore, if the holding time is less than 24 hours, the insulation resistance fluctuates and a stable insulation resistance cannot be obtained.

[0345] In the holding process, if the metal filling member 21 is exposed to an environment with a relative humidity of 10 to 30% for more than 24 hours, the storage location is not particularly limited. Fig.37 The container 40 is stored in the container shown. The container 40 has a container body 42 and a lid 44. In the container 40, the opening U42a of the container body 42 is closed by the lid 44, and the container body 42 is sealed.

[0346] The temperature in the maintenance step may be 25°C or higher, and is preferably 40°C to 50°C.

[0347] Although not shown, a shelf is provided inside the container 42b, for example, and a plurality of metal filling components 21 are stored in the shelf at intervals. If the metal filling components 21 are in contact and stacked, the metal filling components 21 may be damaged when the metal filling components 21 rub against each other due to vibration of the metal filling components 21, so the metal filling components 21 are preferably stored at intervals as described above. If the metal filling components 21 can be stored at intervals one by one, it is not limited to the shelf, and a spacer may be used instead of the shelf.

[0348] Furthermore, as described above, the metal filling member 21 has a rectangular shape, and various containers that can accommodate rectangular substrates can be used as the container 40 .

[0349] When the metal filling member 21 is a circular shape similar to the shape of a general semiconductor wafer, various containers for storing semiconductor wafers can be used as the container 40. As the container 40, a transport container for semiconductor wafers can be used, for example, a front opening wafer transfer box (FOUP) and a front opening wafer shipping box (FOSB) can be used.

[0350] In the holding process, for example, Fig.38 As shown, a storage container 50 and a regulator 52 for regulating the temperature and humidity of an interior 50 a of the storage container 50 are used.

[0351] The storage container 50 is provided with a sensor 53 for recording changes in temperature and humidity of the interior 50a. Based on the temperature information and humidity information from the sensor 53, the adjustment unit 52 adjusts at least the humidity of the interior 50a of the storage container 50. In adjusting the temperature and humidity of the interior 50a of the storage container 50 by the adjustment unit 52, for example, feedback control based on the temperature information and humidity information from the sensor 53 is used.

[0352] The adjustment unit 52 is not particularly limited as long as it can adjust the humidity, for example, and a known air conditioning device can be used. Furthermore, the adjustment unit 52 may be integral with the storage container 50 or may be a separate body.

[0353] In the holding step, exposure to an environment with a relative humidity of 10 to 30% for 24 hours or more is sufficient, so the adjustment unit 52 only needs to have a function of at least adjusting the temperature, and may be a fan for ventilating the interior 50a of the storage container 50.

[0354] In addition, the humidity may be adjusted by placing a desiccant inside the storage container 50 a , or the desiccant may be placed inside the container 40 and only the temperature may be adjusted by the adjustment unit 52 .

[0355] The sensor 53 is not particularly limited as long as it can measure temperature and humidity during storage, but it is preferred that the temperature information and humidity information can be recorded in time series together with the time, that is, can be recorded in time history. Furthermore, the sensor 53 may be wired or wireless.

[0356] In the holding step, a plurality of containers 40 are stored in the interior 50a of the storage container 50, and the adjuster 52 is operated in the stored state to maintain the relative humidity of the metal filling member 21 of the container 40 in the interior 50a of the storage container 50 at 10 to 40%.

[0357] Furthermore, it is preferred that the interior 50a of the storage container 50 is adjusted by the adjustment unit 52 to have a moisture content (g / cm2) of 50% or less at an absolute humidity of 25°C. 3 ) environment. In addition, the absolute humidity at a temperature of 25°C is 50% or less. 3 ) is 11.52 (g / cm 3 By lowering the humidity of the interior 50a of the storage container 50, the amount of moisture in the interior 50a of the storage container 50 can be reduced.

[0358] In this case, for example, the relationship between temperature, humidity and absolute humidity is stored in the adjustment unit 52, and the moisture content of the interior 50a of the storage container 50 is obtained based on the temperature information and humidity information from the sensor 53. The adjustment unit 52 may adjust the temperature and humidity based on the obtained moisture content.

[0359] As described above, the moisture content in the interior 50a of the storage container 50 can be adjusted using a moisture absorbent.

[0360] Furthermore, it is also preferred to store the metal filling component 21 under reduced pressure, which is lower than the atmospheric pressure. As a result, the absolute humidity of the interior 50a of the storage container 50 is reduced. As a result, the variation of the insulation resistance of the metal filling component 21 can be suppressed, and the performance degradation of the metal-filled microstructure can be suppressed. Furthermore, as described above, by storing the metal filling component 21 under reduced pressure, the oxidation of the protrusions 20a and 20b of the conductive path 20 can also be suppressed, thereby improving the bonding strength with the bonding object (such as a semiconductor element and a semiconductor wafer) of the metal filling component 21, and the effect of reducing the bonding resistance with the bonding object can be obtained.

[0361] The above-mentioned reduced pressure can be achieved, for example, by exhausting the air in the interior 50a of the storage container 50, for example, by providing a vacuum pump such as a rotary pump in the adjustment section 52, and further providing a pressure gauge or a pressure sensor for measuring the pressure in the interior 50a of the storage container 50. The pressure gauge and the pressure sensor are not particularly limited as long as they can measure a pressure lower than the atmospheric pressure, and the pressure gauge and the pressure sensor for measuring the pressure can be appropriately used in a normal vacuum container.

[0362] The above-mentioned reduced pressure means that the pressure is about 0.01 to 0.1 Pa.

[0363] Furthermore, although a plurality of the storage containers 50a are provided in the interior 50a of the storage container 50, the present invention is not limited thereto, and the number may be one.

[0364] In this way, the metal filling member 21 can be stored, and the metal filling member 21 can be transferred in the state stored in the storage container 50. Thus, the metal filling member 21 can be transferred to the transfer destination while managing the storage state.

[0365] The container 40 is not limited to the storage container 50. Fig.39 As shown, the electronic components can also be stored in a storage bag 54. The storage bag 54 is made of, for example, a gas barrier film. The gas barrier film is, for example, a film with low water vapor permeability, and a known film used for packaging electronic parts, or a gas barrier film used in organic EL (Electro Luminescence), electronic paper, or solar cells can be used.

[0366] The gas barrier properties are evaluated by water vapor permeability, which is measured by the MOCON method or the like.

[0367] When the container 40 is stored in the storage bag 54, the water vapor permeability of the storage bag 54 is low, and it is difficult to adjust the humidity inside from the outside, so it is preferable to set the desiccant 55 inside the storage bag 54. The amount of the desiccant 55 is determined in advance based on the water vapor permeability of the storage bag 54 used, the size of the container 40, the storage period, etc., and the desiccant 55 of the predetermined amount is set inside the storage bag 54. The container 40 stored in the storage bag 54 is arranged in the interior 50a of the storage container 50 and stored as described above. In this case, the temperature of the interior 50a of the storage container 50 is adjusted by the adjustment unit 52, and the relative humidity of the metal filling member 21 is set to 10 to 40%, and the metal filling member 21 is stored. Even when the container 40 is stored in the storage bag 54, as described above, the pressure of the interior 50a of the storage container 50 can be set to a pressure lower than the atmospheric pressure, and the metal filling member 21 can be stored under reduced pressure.

[0368] And, if Fig.40 As shown, the adjustment unit 52 and the sensor 53 may be provided in the container 40. Even in this case, the metal filling member 21 can be stored in the same manner as when the container 40 is arranged in the interior 50a of the storage container 50. As described above, the pressure in the interior 50a of the storage container 50 can be set to a pressure lower than the atmospheric pressure, and the metal filling member 21 can be stored under reduced pressure.

[0369] like Fig.39 As shown, when using the storage bag 54, Fig.37 The container 40 shown is not essential; Fig.41 As shown, a spacer 56 may be arranged on the metal layer 19 of the metal filling member 21, and a plurality of metal filling members 21 may be stacked and stored in a storage bag 54. In this case, in order to set the relative humidity to 10 to 40%, as shown in FIG. Fig.39 As shown, it is also preferable to arrange the moisture absorbent 55 inside the storage bag 54.

[0370] Paper, resin film, or the like can be used as the spacer 56 . In addition, the spacer 56 may be any spacer that covers at least the metal layer 19 of the metal filling member 21 .

[0371] The present invention is basically configured as described above. The method for producing the metal-filled microstructure of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and various improvements or changes can be made without departing from the gist of the present invention.

[0372] Example

[0373] Below, enumerate embodiment, feature of the present invention is described in more detail.Material, reagent, amount of substance and its ratio and operation etc. shown in following example, as long as do not depart from the gist of the present invention, just can change suitably.Therefore, the scope of the present invention is not limited to following example.

[0374] In this example, metal-filled components of Examples 1 to 9 and Comparative Examples 1 to 3 were produced. The transportability of the metal-filled components of Examples 1 to 9 and Comparative Examples 1 to 3 was evaluated. After ensuring anisotropic conductivity, the insulation resistance of the metal-filled components of Examples 1 to 9 and Comparative Examples 1 to 3 was evaluated. The following describes the evaluation items of transportability and insulation resistance.

[0375] Evaluation of transportability will be described.

[0376] <Evaluation of transportability>

[0377] Using the metal filling member, the transportability was evaluated as follows.

[0378] Regarding transportability, the transport vibration test and the bounce vibration test were performed based on the assumption that the random vibration test described in JIS Z0232:2004 Packaged Goods - Vibration Test Methods was Class 1 according to the general rules of JIS Z0200:2013 Packaged Goods - Performance Test Methods, and the evaluation was performed.

[0379] The packaging method is as follows: while sandwiching the backing paper, 10 pieces of each metal filling component are stacked and sealed in a vinyl chloride box (155mm×155mm×35mm, styrene square box type 19 manufactured by AS ONE Corporation.). A foamed styrene cushioning material with a thickness of 1 cm is arranged above and below the stacked metal filling components. A lid is placed on the box, and each box is laminated and packaged and used as a test material. The backing paper used is AP Clean Paper II A4 pink (72g / m 2 ).

[0380] The temperature and humidity conditions in the transportability test are based on G (+23°C, 50% RH (relative humidity)) in Table 1 (Pretreatment temperature and humidity conditions) of JIS Z 0203:2000. The test material is subjected to a 180-minute random vibration test, followed by a 30-minute bounce test on the same test material.

[0381] After the above test, the metal filling member taken out from the box was visually checked, and the result of the metal filling member with the worst evaluation level among the plurality of metal filling members conveyed in the metal filling unit was used as the overall evaluation.

[0382] The damage to the metal filling portion was evaluated based on the following evaluation criteria. The evaluation results of the transportability are shown in Table 1 below.

[0383] Evaluation Benchmarks

[0384] In the metal-filled component, a case where there is no scratch in the metal layer as the metal-filled portion is defined as A.

[0385] In the metal-filled component, a case where the metal layer as the metal-filled portion has scratches but does not reach the anodized film is designated as B.

[0386] In the metal-filled component, a case where the metal layer as the metal-filled portion has a scratch and reaches the anodized film is defined as C.

[0387] The evaluation of insulation resistance will be described.

[0388] <Evaluation of insulation resistance>

[0389] Regarding the manufactured metal filling parts, after removing the metal layer, the aluminum substrate constituting the valve metal part is removed and set as an anodized film monomer. Then, the surface of the anodized film is polished and smoothed by chemical mechanical polishing (CMP). Thus, anisotropic conductivity is ensured. In this state, on the surface of the anodized film, when the terminal is set 20 mm away, the resistance value is measured using an insulation resistance tester.

[0390] The steps of ensuring anisotropic conductivity of the metal filling member will be described in detail later.

[0391] The insulation resistance was evaluated based on the numerical value of the resistance value according to the following evaluation criteria. The evaluation results of the insulation resistance are shown in Table 1 below.

[0392] Evaluation Benchmarks

[0393] A: Resistance R>10MΩ

[0394] B: 10MΩ≥Resistance R>1MΩ

[0395] C: 1MΩ≥Resistance R>10kΩ

[0396] D: 10kΩ≥Resistance R>1kΩ

[0397] E: 1kΩ≥Resistor R

[0398] Hereinafter, Examples 1 to 9 and Comparative Examples 1 to 3 will be described.

[0399] (Example 1)

[0400] The metal filling member of Example 1 will be described.

[0401] [Metal filled parts]

[0402] <Aluminum substrate>

[0403] An aluminum substrate having a purity of 99.999% by mass was used, and the thickness of the aluminum substrate was set to 120 μm.

[0404] The aluminum substrate was trimmed to a size of 15 cm square, and a high-viscosity tape was attached to form a frame with a width of 5 mm around it. The size of the anodized film 16 portion inside the frame was set to 14 cm square. For the high-viscosity tape, Dunplon (registered trademark) tape No. 375 (width 25 mm×length 50 m) manufactured by NITTO DENKO CS SYSTEM CORPORATION was used.

[0405] <Electrolytic grinding treatment>

[0406] The aluminum substrate was subjected to electrolytic polishing treatment using an electrolytic polishing liquid with the following composition at a voltage of 10 V, a liquid temperature of 65° C., and a liquid flow rate of 3.0 m / min. The electrolytic treatment area was set to 0.12 m 2 .

[0407] A carbon electrode was used as the cathode, and GP0110-30R (manufactured by TAKASAGO LTD.) was used as the power source. The flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation.).

[0408] (Electrolytic polishing liquid composition)

[0409] 85 mass% phosphoric acid (Wako Pure Chemical, Ltd. reagent) 660 mL

[0410] ·160mL pure water

[0411] · Sulfuric acid 150mL

[0412] · Ethylene glycol 30mL

[0413] <Anodizing process>

[0414] Next, the aluminum substrate after the electrolytic polishing treatment was subjected to anodizing treatment by a self-regularization method according to the procedure described in Japanese Patent Application Laid-Open No. 2007-204802.

[0415] The aluminum substrate after the electrolytic polishing treatment was subjected to a preliminary anodizing treatment for 1 hour using a 0.50 mol / L oxalic acid electrolyte at a voltage of 45 V, a liquid temperature of 16° C., and a liquid flow rate of 3.0 m / min.

[0416] Then, a film removal treatment was performed on the aluminum substrate after the preliminary anodizing treatment by immersing it in a 0.6 mol / L phosphoric acid aqueous solution (liquid temperature: 40° C.) for 0.5 hours.

[0417] Then, anodization was performed again using an electrolyte solution of 0.50 mol / L oxalic acid at a voltage of 45 V, a liquid temperature of 16° C., and a liquid flow rate of 3.0 m / min to partially anodize the surface of the aluminum substrate, thereby forming an anodized film with a thickness of 50 μm.

[0418] Thus, a structure having an aluminum substrate having a frame portion having a width of 5 mm at the outer edge and an anodized film provided in the frame portion of the aluminum substrate was obtained.

[0419] In addition, the pre-anodization treatment and the re-anodization treatment were both carried out in a state where the aluminum substrate was masked with a high-viscosity tape. In addition, in the pre-anodization treatment and the re-anodization treatment, the cathode was a titanium electrode, and the power supply used was PAM320-12 (manufactured by KIKUSUI ELECTRONICS CORPORATION). In addition, the cooling device used NeoCoolBD36 (manufactured by Yamato Scientific Co., Ltd.), and the stirring and heating device used a paired stirrer PS-100 (manufactured by EYELATOKYO RIKAKIKAI CO, LTD.). In addition, the flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by ASONE Corporation.).

[0420] <Barrier layer removal process>

[0421] Next, electrolysis treatment (electrolytic removal treatment) was performed under the same treatment solution and treatment conditions as the above-mentioned anodizing treatment while continuously decreasing the voltage from 40 V to 0 V at a voltage decreasing rate of 0.2 V / sec. For the electrolysis treatment, PK45-9 (model, manufactured by Matsusada Precision Inc.) was used as a DC power source.

[0422] After the anodized substrate was fully washed with running water, it was dried with low-temperature wind within a few minutes. After the anodized substrate was alternately immersed in ion exchange water (50°C) and a solution containing a surfactant (45°C) for 3 minutes each, the ion exchange water was drained, and then it was provided in a wet state for the barrier layer removal treatment. In addition, as a solution containing a surfactant, a solution prepared by diluting the pretreatment solution "NeutraClean 68" manufactured by ROHM AND HAAS ELECTRONIC MATERIALS KK with ion exchange water at a ratio of 1:4 was used.

[0423] The etching treatment (barrier layer removal treatment) was carried out by immersing in a sodium hydroxide solution containing metallic zinc maintained at a supersaturated state at a temperature of 25° C. for 2 minutes, and then the barrier layer present at the bottom of the anodized film was removed by washing with water, and a zinc conductive layer was formed on the surface of the aluminum substrate exposed through the micropores. The sodium hydroxide solution containing metallic zinc used a solution in which 2000 ppm of zinc oxide was dissolved in a sodium hydroxide aqueous solution (NaOH=52 g / L).

[0424] Here, the average diameter of the micropores (pores) present in the anodized film after the barrier layer removal process is 60nm. In addition, the average diameter is calculated as follows: a surface photograph (50,000 times magnification) is taken by FE-SEM (Field emission-Scanning Electron Microscope: Field emission scanning electron microscope) as the average value of 50 points.

[0425] And, the average thickness of the anodized film after the barrier layer removal process is 40 μm. That is, the average thickness of the oxide film is 40 μm. In addition, the average thickness of the anodized film is calculated as follows: the anodized film is cut in the thickness direction by FIB (Focused Ion Beam), and the surface photograph of its cross section is taken by FE-SEM (50,000 times magnification) as the average value of 10 points.

[0426] The density of micropores in the anodized film is about 100 million / mm 2 The density of micropores was measured and calculated by the method described in paragraphs

[0168] and

[0169] of Japanese Patent Application Laid-Open No. 2008-270158.

[0427] And, the regularity of the micropores present in the anodized film is 92%. In addition, the regularity is measured and calculated by taking surface photos (20,000 times magnification) by FE-SEM, and by the method described in paragraphs

[0024] to

[0027] of Japanese Patent Publication No. 2008-270158.

[0428] <Metal filling process>

[0429] Next, electroplating was performed using the aluminum substrate as a cathode and copper as a positive electrode.

[0430] Specifically, constant current electrolysis is performed using a copper plating solution of the composition shown below to obtain a metal-filled component in which the micropores are filled with copper and a metal layer composed of copper is also formed on the frame. The thickness δ of the metal layer on the frame (refer to Figure 6 ) is 50μm.

[0431] Here, constant current electrolysis was performed using PAS20-36 (manufactured by KIKUSUI ELECTRONICS CORP.) as a power source, a plating apparatus manufactured by Novell, Inc., and a power source (HZ-3000) manufactured by HOKUTO DENKO CORPORATION. After confirming the deposition potential by cyclic voltammetry in the plating solution, the treatment was performed under the following conditions.

[0432] (Copper plating solution composition and conditions)

[0433] ·Copper sulfate 100g / L

[0434] ·Sulfuric acid 1g / L

[0435] ·Hydrochloric acid 15g / L

[0436] ·SPS (3,3′-dithiobis(1-propanesulfonic acid) disodium) 8.5ppm

[0437] PEG (polyethylene glycol) 5ppm

[0438] Temperature 30℃

[0439] Current density 10A / dm 2

[0440] In order to evaluate the insulation resistance, 10 sheets of the manufactured metal filling components were stacked and placed in a vinyl chloride box with a lid closed, and then stored in a low humidity type low temperature thermostatic hygrostat (PDL-4J (model) manufactured by ESPEC CORP.). The inside of the low humidity type low temperature thermostatic hygrostat was set to an environment of 40°C and a relative humidity of 20%, and after exposure for 25 hours, the following process was performed.

[0441] <Barrier layer removal process>

[0442] The metal layer of the metal-filled component was removed using an adhesive tape. Dunplon tape No. 375 (manufactured by NITTO DENKO CORPORATION) was used as the adhesive tape.

[0443] <Substrate removal process>

[0444] Next, the aluminum substrate was dissolved and removed by immersing the substrate in a 20 mass % aqueous solution of mercuric chloride (mercuric chloride) at 20° C. for 3 hours, thereby producing an anodic oxide film alone.

[0445] <Smoothing process>

[0446] Thus, the surface of the anodized film is subjected to CMP (Chemical Mechanical Polishing) treatment and the surface is polished to smooth the surface. Anisotropic conductivity is ensured by the smoothing process. In this state, the above insulation resistance is measured.

[0447] In the smoothing process, a grinding device (BC-15CN (trade name)) manufactured by MAT is used. The surface of the anodized film is ground once with an abrasive containing aluminum oxide (a solution prepared by diluting WA#8000 (FF) manufactured by Kemet Japan Co., Ltd. to 4 times with pure water), and then ground twice with an abrasive containing silicon dioxide (S-A1-1-0 manufactured by Kemet Japan Co., Ltd.). The arithmetic mean roughness (JIS B0601:2001) of the finished surface after grinding is set to 0.005 μm.

[0448] (Example 2)

[0449] The difference between Example 2 and Example 1 is that the holding time is 30 hours, and the other points are the same as those of Example 1.

[0450] (Example 3)

[0451] Compared with Example 1, Example 3 is different in that the holding time is 40 hours, and other than that, the same as Example 1 is used.

[0452] (Example 4)

[0453] The difference between Example 4 and Example 2 is that the width of the frame portion is 3 mm, and other than that, the same as Example 1. In Example 4, the high-viscosity tape is attached so as to form a frame with a width of 3 mm around the periphery.

[0454] (Example 5)

[0455] Example 5 is different from Example 3 in that the thickness of the frame portion is 240 μm, and other than that, the same procedures as Example 1 are employed. In Example 5, an aluminum substrate having a thickness of 240 μm is used.

[0456] (Example 6)

[0457] The difference between Example 6 and Example 2 is that the relative humidity is 10%, and the other points are the same as those of Example 1.

[0458] (Example 7)

[0459] The difference between Example 7 and Example 3 is that the relative humidity is 30%, and the other points are the same as those of Example 1.

[0460] (Example 8)

[0461] Example 8 differs from Example 3 in that the average diameter is 40 nm, but otherwise is the same as Example 1. In Example 8, anodization treatment is performed in a 15% sulfuric acid aqueous solution at a voltage of 25 V with the liquid temperature set to 3° C., and the average diameter is set to 40 nm.

[0462] (Example 9)

[0463] Example 9 differs from Example 3 in that the average diameter is 200 nm, but is otherwise the same as Example 1. In Example 9, anodization treatment is performed in a 0.1 M phosphoric acid aqueous solution at a voltage of 195 V and a liquid temperature of 3° C., and the average diameter is set to 200 nm.

[0464] (Comparative Example 1)

[0465] Comparative Example 1 is different from Example 1 in that the holding time is 20 hours, and the other points are the same as Example 1.

[0466] (Comparative Example 2)

[0467] Comparative Example 2 differs from Example 1 in that it has a structure without a frame portion, and other than that, it is the same as Example 1. In Comparative Example 2, an anodic oxide film is formed on the entire surface of a valve metal member to produce a metal filling member.

[0468] (Comparative Example 3)

[0469] Comparative Example 3 is different from Example 1 in that the relative humidity is 40%, and is the same as Example 1 except for this.

[0470] [Table 1]

[0471]

[0472] As shown in Table 1, in Examples 1 to 9, compared with Comparative Examples 1 to 3, good results were obtained regarding the transportability and insulation resistance.

[0473] In Comparative Example 1, the holding time was short and the insulation resistance result was poor. In Comparative Example 3, there was no frame part and the transportability result was poor. In Comparative Example 5, the relative humidity was high and the insulation resistance result was poor.

[0474] Explanation of symbols

[0475] 11, 15-valve metal parts, 11a, 15a, 16a, 26a, 61a-surface, 11b, 16e-outer edge, 11c, 15c-region, 11e-bottom, 12, 13, 14-mask, 13a-opening, 15b-outer edge, 15d-frame part, 15e-bottom, 16-anodized film, 16b-back surface, 17-through hole, 18-structure, 19-metal layer, 20-conducting path, 20a, 20b-protrusion, 21-metal filling part, 22-resin base material, 24-support body, 2 6-resin layer, 27-peeling layer, 28-supporting layer, 29-peeling agent, 30-double-sided adhesive, 31-supporting member, 32-metal-filled microstructure, 40-container, 42-container body, 42a-opening, 42b-container interior, 44-lid, 50-storage container, 50a-interior, 52-adjusting part, 53-sensor, 54-storage bag, 55-moisture absorbent, 56-spacer, 60-electrode body, 61-insulating support body, 62-conductive layer, 63-anti-etching layer, Dt-thickness direction, h-thickness, H A -thickness, p - center spacing, Q - area, x - direction, δ - thickness.

Claims

1. A method for manufacturing a metal-filled microstructure, comprising: a forming step of forming an oxide film having a plurality of pores in a forming region surrounded by a frame portion arranged at an outer edge of the valve metal member, thereby obtaining a structure having the valve metal member and the oxide film; a filling step of filling the plurality of pores of the oxide film of the structure with metal; and a holding step of exposing the metal-filled member obtained by filling the plurality of pores of the oxide film with metal in the structure in the filling step to an environment with a relative humidity of 10% to 30% for more than 24 hours, The average diameter of the plurality of pores is 1 μm or less, The filling step is a step of filling the plurality of pores with the metal by forming a metal layer on the surface of the structure. In the filling step, the metal layer having a thickness of 100 μm or less is formed on the frame portion. After the holding step, there is a metal layer removing step of removing the metal layer formed on the surface of the structure.

2. The method for producing a metal-filled microstructure according to claim 1, in, The valve metal component is composed of aluminum.

3. The method for producing a metal-filled microstructure according to claim 1 or 2, in, The oxide film is an anodic oxide film.

4. The method for producing a metal-filled microstructure according to claim 3, in, The anodic oxide film is Al 2 O 3 membrane.

5. The method for producing a metal-filled microstructure according to claim 1 or 2, in, In the filling step, the metal filled in the plurality of pores of the oxide film is copper.

6. The method for producing a metal-filled microstructure according to claim 1, in, After the metal layer removal step, there is a surface smoothing step of smoothing the surface of the oxide film.

7. The method for producing a metal-filled microstructure according to claim 6, in, The surface smoothing treatment step uses chemical mechanical polishing, dry etching or grinding for smoothing.

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