JP6764809B2 - Manufacturing method of metal-filled microstructure - Google Patents

Description

The present invention relates to a method for manufacturing a metal-filled microstructure in which there are a plurality of through-passages penetrating in the thickness direction of an insulating base material and the through-passage is filled with metal, and in particular, metal is contained inside the through-passage. The present invention relates to a method for producing a metal-filled microstructure in which the surface smoothing treatment of an insulating base material in a filled state is stopped by detecting the end point.

A metal-filled microstructure in which micropores provided in an insulating base material are filled with metal is one of the fields that have been attracting attention in nanotechnology in recent years, and is expected to be used as an anisotropic conductive member, for example. Has been done.
Since the heterogeneous conductive member can obtain an electrical connection between the electronic component and the circuit board simply by inserting it into the electronic component such as a semiconductor element and the circuit board and pressurizing it, the electronic component such as a semiconductor element can be used. It is widely used as an electrical connection member and an inspection connector for performing functional inspections.
In particular, electronic components such as semiconductor elements are remarkably downsized, and connection stability is achieved by methods such as conventional wire bonding in which wiring boards are directly connected, flip chip bonding, and thermocompression bonding. Since it is not possible to sufficiently guarantee the above, an anisotropic conductive member is attracting attention as an electronic connection member.

Patent Document 1 describes a microstructure in which some micropore through-holes are filled with a substance other than the material of the base material for a base material having micropore through-holes at a density of 10 million pieces / mm ² or more. The manufacturing method of is described. It is described that after filling the micropore through holes with a substance other than the material of the base material, a surface smoothing treatment is performed in which the front surface and the back surface of the base material are smoothed by a chemical mechanical polishing treatment.

Japanese Unexamined Patent Publication No. 2013-167023 JP 2015-8303 Japanese Patent Application Laid-Open No. 2014-513435 Special Table 2014-514770

Patent Document 1 describes that in a method for producing a microstructure, smoothing is performed by a chemical mechanical polishing treatment, but the detection mode of the end point of smoothing is not clear. If the area ratio of the microstructure is not within a certain range, no change can be seen even if the surface of the conduction path is exposed, and it is difficult to detect with the conventional detection technique. Similarly, if the diameter of the conduction path is not within a certain range, no change can be seen even if the surface of the conduction path is exposed, and it is difficult to detect the end point where the surface of the conduction path is exposed by the conventional detection technique. In addition, by polishing with a slurry that has the function of etching the insulating base material, it is possible to prevent the desorbed material from becoming coarse due to polishing, damage the detection window, and increase the roughness of the polished surface. It is possible to reduce the adverse effect on detection by.
Here, Patent Document 2 describes a platen that is driven by a motor and rotates in the horizontal direction, an observation window provided on the platen, a polishing pad provided on the surface of the platen corresponding to the observation window, and an observation window. A polishing end point detection device having a spectroscopic device that captures optical information reflected from the wafer via the above is described. In Patent Document 2, the time point at which all the periodic change tendencies of the positions of a plurality of nodes of the spectral waveform become discontinuous in the continuous time change map is detected and detected as the polishing end point. However, Patent Document 2 is not a microstructure in which the object to be polished is a semiconductor wafer and some micropore through holes are filled with a substance other than the material of the base material as in Patent Document 1. Therefore, it cannot always be said that the polishing end point detection of Patent Document 2 for detecting the exposure of a material that is neither the base material nor the conduction path is effective.

Further, the method of chemically and mechanically polishing the substrate described in Patent Document 3 is to polish the metal layer on the substrate at the polishing station and to determine the thickness of the metal layer by eddy current at the polishing station during polishing. It includes monitoring by a monitoring system and stopping polishing when the eddy current monitoring system indicates that the metal layer residue has been removed from the lower layer and the upper surface of the lower layer is exposed.
The method of chemically and mechanically polishing the substrate described in Patent Document 4 is to polish the metal layer on the substrate at the polishing station and to determine the thickness of the metal layer in the eddy current monitoring system at the polishing station during polishing. In the polishing station, based on the metal layer thickness measurements from the eddy current monitoring system, to reduce the difference between the metal layer's expected thickness profile and the target profile. The metal layer has a resistance of more than 700 ohm ongstrom, including controlling the pressure applied to the substrate by the carrier head during polishing of the metal layer.

It is described that the methods of chemically and mechanically polishing the substrates of Patent Documents 3 and 4 can be used to detect the flattening of metal pillars, but Patent Documents 3 and 4 use metal pillars. I'm monitoring. Therefore, in the case where the micropores are sufficiently filled with metal and the micropores are not sufficiently filled with metal in the microstructure, the end point cannot be reliably detected.
Further, in order to smooth the region where the micropores are sufficiently filled with metal and the region where the micropores are not sufficiently filled with metal as described above, it is necessary to increase the amount of polishing. There is a poor production efficiency. Moreover, when the amount of polishing is large and overpolishing is performed, there arises a problem that the final film thickness becomes too thin or the film thickness variation becomes large.

An object of the present invention is to solve the above-mentioned problems based on the prior art, and to provide a metal-filled microstructure in which there are a plurality of through-passages penetrating in the thickness direction of the insulating base material and the through-passages are filled with metal. It is an object of the present invention to provide a method for producing a metal-filled microstructure for detecting an end point in the surface smoothing treatment of the above.

In order to achieve the above object, the present invention comprises an insulating base material, a plurality of through-passages penetrating in the thickness direction of the insulating base material, and a plurality of through-passages made of a metal filled inside the through-passages. A method for manufacturing a metal-filled microstructure having a conduction path, wherein the area ratio of the conduction path to the surface of the insulating base material is 15% or more and 50% or less, and the diameter of the conduction path is 20 nm or more and 110 nm or less. A metal having a surface smoothing treatment step of smoothing at least one surface of an insulating base material whose through-passage is filled with metal, and the surface smoothing treatment step performs end point detection to detect the end point and stops. It provides a method for manufacturing a filled microstructure.

It is preferable to carry out a surface smoothing treatment step on both surfaces of the insulating base material whose through-passage is filled with metal.
For end point detection, it is preferable to optically detect the end point. Further, in the end point detection, it is preferable to electrically detect the end point.
It is preferable to detect the end point when the surface of the insulating base material and the end face of the conduction path have a surface roughness of 20 nm or less as the end point.

For the smoothing of the surface smoothing treatment step, it is preferable to use chemical mechanical polishing, dry etching or grinding.
For chemical mechanical polishing, it is preferable to use a slurry having an action of etching an insulating base material.
It is preferable to use the reflectance of the insulating base material for the end point detection for optically detecting the end point.
Chemical mechanical polishing is used for smoothing the surface smoothing treatment step, and end point detection for electrically detecting the end point is performed on at least one surface of the abrasive body used for chemical mechanical polishing and the insulating base material. It is preferable to use a rotational torque that represents the frictional force between the two.
In the surface smoothing treatment step, it is preferable that smoothing is performed and the end point is detected during smoothing.

According to the present invention, it is possible to detect the end point and automatically stop polishing, and it is possible to efficiently manufacture the product.

It is a schematic perspective view which shows an example of the smoothing apparatus used in the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows one step of the manufacturing method of the metal-filled microstructure of the embodiment of this invention. It is a top view which shows an example of the structure of the metal-filled microstructure of the embodiment of this invention. It is a schematic cross-sectional view which shows an example of the structure of the metal-filled microstructure of the embodiment of this invention. It is a schematic diagram which shows an example of the state before the surface smoothing process process of the metal-filled microstructure of the embodiment of this invention. It is a schematic diagram which shows an example of the state before the surface smoothing process process of the metal-filled microstructure of the embodiment of this invention. It is a schematic diagram which shows an example of the state after the surface smoothing process process of the metal-filled microstructure of embodiment of this invention. It is a flowchart which shows an example of the surface smoothing processing process of the metal-filled microstructure of embodiment of this invention.

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.
It should be noted that the figures described below are exemplary for explaining the present invention, and the present invention is not limited to the figures shown below.
In the following, "~" indicating the numerical range includes the numerical values described on both sides. For example, when ε is a numerical value α to a numerical value β, the range of ε is a range including the numerical values α and the numerical value β, and in mathematical symbols, α ≦ ε ≦ β.
Angles such as "orthogonal" include error ranges generally tolerated in the art in question, unless otherwise stated. “Same” also includes the error range generally acceptable in the relevant technical field.

Regarding the method for manufacturing the metal-filled microstructure, first, the smoothing device used in the method for manufacturing the metal-filled microstructure will be described.
The metal-filled microstructure includes an insulating base material, a plurality of through-passages penetrating in the thickness direction of the insulating base material, and a plurality of conduction paths made of metal filled inside the through-passages. To have. The metal-filled microstructure will be described in detail later.

FIG. 1 is a schematic perspective view showing an example of a smoothing device used in the method for manufacturing a metal-filled microstructure according to an embodiment of the present invention.
The smoothing device 100 shown in FIG. 1 is a polishing device that performs polishing generally called chemical mechanical polishing (CMP). The smoothing device 100 has a rotating rotary surface plate 102, a polishing pad 104 provided on the rotary surface plate 102, and a rotating head 106 that holds the object to be polished W on the polishing pad.
The rotary surface plate 102 is rotated in a predetermined direction at a predetermined rotation speed by a motor 108 provided via a rotation shaft 102a.

The smoothing device 100 is further provided with a sensor 110 below the rotary surface plate 102 to observe the object to be polished W through the rotary surface plate 102 and the polishing pad 104.
The rotation head 106 has a rotation shaft 106a, and an adjustment unit 112 is provided on the rotation shaft 106a. The adjusting unit 112 adjusts the pressing force that presses the object to be polished W against the polishing pad 104, the rotation speed of the rotating head 106, and the like.
Further, a supply unit 114 for supplying the polishing liquid 113 to the polishing pad 104 is provided. The supply unit 114 includes a tank for storing the polishing liquid 113 (not shown), a pump for supplying the polishing liquid 113 (not shown), and the like. The polishing liquid 113 is for polishing the object W to be polished. As the polishing liquid 113, one suitable for the composition of the object W to be polished, the amount of polishing, the degree of finishing of the polished surface, and the like is appropriately used. As the polishing liquid 113, a slurry having an action of etching the object W to be polished can also be used.

The entire device of the smoothing device 100 is controlled by the control unit 116. The motor 108, the sensor 110, the adjusting unit 112, and the supply unit 114 are controlled by the control unit 116. In the smoothing device 100, the rotation of the rotary surface plate 102 is stopped, the rotation of the rotary head 106 is stopped, and the polishing is stopped based on the detection signal of the end point detection indicating that the polishing is completed from the sensor 110.

In the surface smoothing treatment step described later, as will be described later, the metal filled as the conduction path 19 which is the object W to be polished and the anodized film 16 are flattened until they are flush with each other, that is, an insulating group. The surface of the material and the end surface of the conduction path 19 are flattened to the same surface. At this time, when the surface of the metal constituting the conduction path 19 is exposed, an optical change such as a change in the reflected light of the anodized film 16 or a cover with the rotating head 106 or the rotating surface plate 102 of the smoothing device 100. The frictional force with the abrasive body W is used, and the end point is detected by using the change in the frictional force. The rotating head 106 including the polishing pad 104 or the rotating surface plate 102 corresponds to the polishing body.
From the above, for example, an optical sensor is used as the sensor 110, and the end point is optically detected in the end point detection. When the end point is optically detected in the end point detection, the detection signal indicating the end point of the end point detection by the sensor 110 is exemplified by the reflectance and color of light. Further, the configuration of the sensor 110 is not particularly limited as long as it can measure the reflectance and color of light, and a known sensor 110 can be used as appropriate.
In the present invention, the same planar shape means a state in which the surface roughness is 30 nm. Here, the surface roughness is an arithmetic average roughness Ra (JIS (Japanese Industrial Standards) B 0601-2001).

An electric sensor may be used for the sensor 110 to detect the rotation torque of the rotation shaft 106a of the rotation head 106 or the rotation torque of the rotation shaft 102a of the rotation platen 102, and the rotation torque may be used as a detection signal for detecting the end point. .. The rotational torque represents the above-mentioned frictional force. By using the change in the rotational torque, the end point can be detected in the same manner as the change in the frictional force described above.
Further, the reaction force with respect to the pressing force of the rotating head 106 may be measured, and this reaction force may be used as a detection signal for detecting the end point. The reaction force against the pressing force of the rotating head 106 also represents the above-mentioned frictional force. By using the change in reaction force, the end point can be detected in the same manner as the change in frictional force described above.
The rotational torque and reaction force can be detected using, for example, a strain sensor. In this case, the rotational torque and reaction force are detected in the form of electrical signals from the strain sensor. In this way, the end point detection using the rotational torque and the reaction force electrically detects the end point.
Further, the thickness of the object to be polished W is measured by using, for example, a film thickness meter using an eddy current, and when a predetermined film thickness is reached, the end point is set and a detection signal for detecting the end point is output. You may. Even with a film thickness meter that uses eddy currents, the end point detection electrically detects the end point.

The smoothing device 100 polishes the object to be polished W, and detects the end point by sensing with the sensor 110 during polishing of the object W to be polished, and obtains a detection signal for detecting the end point. The smoothing device 100 can detect the end point in a so-called in situ state. However, the smoothing device 100 is not limited to this configuration, and the polishing is temporarily stopped, the end point detection for detecting the end point of the object W to be polished is performed, and if the end point is not reached, polishing is performed again. It may be repeated until the end point is reached. In this case, for example, a mechanism for moving the rotary head 106 from the rotary surface plate 102 is provided, the rotary head 106 is moved, the object W to be polished is separated from the polishing pad 104, and then the end point of the object W to be polished is detected. To do.

The smoothing device 100 is a polishing device that smoothes the object W to be polished by performing polishing generally called chemical mechanical polishing as described above, but carries out a surface smoothing treatment step described later. If it can be done, the device configuration is not particularly limited. For smoothing, in addition to chemical mechanical polishing, dry etching or grinding may be used.

2 to 12 are schematic cross-sectional views showing the manufacturing method of the metal-filled microstructure according to the embodiment of the present invention in the order of steps. The metal-filled microstructure will be described by taking as an example a structure manufactured using an aluminum substrate. When an aluminum substrate is used for manufacturing a metal-filled microstructure, the insulating base material is composed of an anodic oxide film.
As shown in FIG. 2, first, the aluminum substrate 10 is prepared. The size and thickness of the aluminum substrate 10 are appropriately determined according to the thickness of the finally obtained metal-filled microstructure, the device to be processed, and the like.

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

The surface of one side of the aluminum substrate on which the anodizing film is formed by the anodizing treatment preferably has an aluminum purity of 99.5% by mass or more, more preferably 99.9% by mass or more, and 99. It is more preferably .99% by mass or more. When the aluminum purity is in the above range, the regularity of the arrangement of the micropores, which are the through-passages, becomes sufficient.
The aluminum substrate 10 is not particularly limited as long as it can form an anodized film, and for example, JIS (Japanese Industrial Standards) 1050 material is used.

The surface 10a on one side of the aluminum substrate 10 to be anodized is preferably heat-treated, degreased, and mirror-finished in advance.
Here, regarding the heat treatment, the degreasing treatment, and the mirror finishing treatment, the same treatments as those described in paragraphs [0044] to [0054] of JP-A-2008-270158 can be performed.
The mirror finish treatment before the anodic oxidation treatment is, for example, electrolytic polishing, and for the electrolytic polishing, for example, an electrolytic polishing liquid containing phosphoric acid is used.

Next, the surface 10a on one side of the aluminum substrate 10 is anodized, and the surface 10a on one side of the aluminum substrate 10 is anodized to form micropores. As a result, as shown in FIG. 3, an anode having an aluminum base material 14 and an anode oxide film 16 having a plurality of through-passages 17 extending in the thickness direction D of the aluminum base material 14 on the surface 14a of the aluminum base material 14. The oxidized structure 12 is formed. The above-mentioned anodizing step is also referred to as an anodizing treatment step.

[Anodizing process]
For the anodic oxidation treatment, a conventionally known method can be used, but from the viewpoint of increasing the regularity of the arrangement of micropores and ensuring the anisotropic conductivity of the metal-filled microstructure, a self-regulation method or a constant voltage is used. It is preferable to use the treatment.
Here, with respect to the self-regularization method and the constant voltage treatment of the anodizing treatment, the same treatments as those described in paragraphs [0056] to [0108] of JP-A-2008-270158 can be applied.

The anodized film 16 having a plurality of through-passages 17 has a barrier layer (not shown) at the bottom of the through-passages 17. It has a barrier layer removing step of removing the barrier layer.

[Barrier layer removal process]
After the anodizing treatment, for example, the barrier layer of the anodic oxide film 16 is removed by using an alkaline aqueous solution containing a metal having a hydrogen overvoltage higher than that of aluminum. By removing the barrier layer, a metal layer (not shown) made of a metal having a hydrogen overvoltage higher than that of aluminum described above is formed at the bottom of the gangway 17.

Here, the hydrogen overvoltage means a voltage required for hydrogen to be generated when water is electrolyzed. For example, the hydrogen overvoltage of aluminum (Al) is −1.66 V (Japan). Journal of the Society of Chemistry, 1982, (8), p1305-1313). Examples of metals higher than the hydrogen overvoltage of aluminum and the value of the hydrogen overvoltage are shown below.
<Metal and hydrogen (1NH ₂ SO ₄ ) overvoltage>
-Platinum (Pt): 0.00V
-Gold (Au): 0.02V
-Silver (Ag): 0.08V
-Nickel (Ni): 0.21V
-Copper (Cu): 0.23V
-Tin (Sn): 0.53V
-Zinc (Zn): 0.70V

Next, as shown in FIG. 4, the anodized structure 12 is filled with metal in the through-passage 17 of the anodized film 16. As a result, the conductive conduction path 19 is formed. The filling of the metal into the inside of the gangway 17 is also referred to as a metal filling step, and for example, an electrolytic plating process is used. The filling of the metal will be described in detail later. The step of filling the metal is performed on the anodized structure 12.

[Metal filling process]
<Metal to be filled>
Metal filled in the above-described through-passage 17 is preferably an electric resistivity is less material 10 ³ [Omega] cm, and specific examples thereof include gold (Au), silver (Ag), copper (Cu) , Aluminum (Al), Magnesium (Mg), Nickel (Ni), Zinc (Zn) and the like are preferably exemplified.
Among them, from the viewpoint of electrical conductivity, Cu, Au, Al and Ni are preferable, Cu and Au are more preferable, and Cu is further preferable.

<Filling method>
As an electrolytic plating treatment method for filling the inside of the gangway 17 with metal, for example, an electrolytic plating method or an electroless plating method can be used.
Here, it is difficult to selectively deposit (grow) a metal in the pores with a high aspect ratio by a conventionally known electrolytic plating method used for coloring or the like. It is considered that this is because the precipitated metal is consumed in the pores and the plating does not grow even if electrolysis is performed for a certain period of time or longer.

Therefore, in the production method of the present invention, when the metal is filled by the electrolytic plating method, it is necessary to allow a rest time during pulse electrolysis or constant potential electrolysis. The rest time is required to be 10 seconds or more, preferably 30 to 60 seconds.
It is also desirable to add ultrasonic waves to promote the agitation of the electrolyte.
Further, the electrolytic voltage is usually 20 V or less, preferably 10 V or less, but it is preferable to measure the precipitation potential of the target metal in the electrolytic solution to be used in advance and perform constant potential electrolysis within the potential + 1 V. When performing constant potential electrolysis, it is desirable that cyclic voltammetry can be used in combination, and a potentiostat device such as Solartron, BAS, Hokuto Denko, and IVIUM can be used.

As the plating solution, a conventionally known plating solution can be used.
Specifically, an aqueous solution of copper sulfate is generally used for precipitating copper, but the concentration of copper sulfate is preferably 1 to 300 g / L, more preferably 100 to 200 g / L. preferable. Moreover, precipitation can be promoted by adding hydrochloric acid to the electrolytic solution. In this case, the hydrochloric acid concentration is preferably 10 to 20 g / L.
When depositing gold, it is desirable to use a sulfuric acid solution of tetrachloroauric acid and perform plating by AC electrolysis.

In the electroless plating method, when the through-passage 17 is a hole made of micropores having a high aspect, it takes a long time to completely fill the inside of the through-passage 17 with metal, so the metal is filled by the electrolytic plating method. It is desirable to do.

As shown in FIG. 4, after the inside of the through-passage 17 is filled with metal to form the conduction passage 19, the support 40 is provided on the opposite side of the anodic oxide film 16 with respect to the aluminum base material 14. In this case, more specifically, as shown in FIG. 5, the resin base material 42 is used, and the support 40 is provided on the back surface 14b of the aluminum base material 14.
As the resin base material 42, for example, a functional adsorption film is used. As the functional adsorption film, Q-chuck (registered trademark) (manufactured by Maruishi Sangyo Co., Ltd.) or the like can be used.
The support 40 preferably has the same outer shape as the anodized structure 12 shown in FIG. The support 40 supports the anodized structure 12 in a later step. By attaching the support 40, the handleability is increased.

Next, as shown in FIG. 5, the surface 16a of the anodized film 16 is polished in a form in which the support 40 is attached to the anodized structure 12, and as shown in FIG. 6, the conduction path 19 and the anodized film are formed. Flatten 16 until it is flush with the surface. The step of polishing the surface 16a of the anodized film 16 and flattening it until it becomes the same surface as described above is called a surface smoothing treatment step. As described above, the polishing is, for example, chemical mechanical polishing by the smoothing device 100. The metal-filled microstructure 13 is formed through the surface smoothing treatment step.

Here, FIG. 16 is a schematic view showing an example of a state before the surface smoothing treatment step of the metal-filled microstructure of the embodiment of the present invention, and FIG. 17 is a schematic view of the metal-filled microstructure of the embodiment of the present invention. It is a schematic diagram which shows an example of the state after a surface smoothing process. FIG. 18 is a flowchart showing an example of a surface smoothing treatment step of the metal-filled microstructure according to the embodiment of the present invention.
When the inside of the gangway 17 is filled with metal as described above, it is not uniformly filled, and as shown in FIG. 4, the portion 20 filled with metal overflowing with respect to the gangway 17 and the gangway 17 are filled. On the other hand, there may be a portion 21 that is not sufficiently filled with metal. In this case, the distribution of the metal on the surface 16a of the anodized film 16 is not uniform. When this state is viewed in a plan view, the reflection of light becomes non-uniform, and as shown in FIG. 16, it is visually recognized as unevenness.

In the surface smoothing treatment step, when polishing the anodic oxide film 16 having the conduction path 19, which is an insulating base material whose through-pass is filled with metal, as the object W to be polished, the surface of the anodic oxide film 16 is polished. It is necessary to polish 16a so that the anodized film 16 and the conduction path 19 are on the same surface. That is, it is necessary to polish the surface of the anodized film 16 and the end surface of the conduction path 19 so that the surface roughness is 20 nm or less.
The end point of the surface 16c of the anodized film 16 (see FIG. 6) and the end surface 19c of the conduction path 19 (see FIG. 6) is a state in which the surface roughness is 30 nm or less, and this end point is detected in the end point detection.
If the metal is not uniformly filled in the gangway 17 as described above, it is necessary to polish the surface 16c shown in FIG. When the surface 16c shown in FIG. 5 is polished, the reflection of light becomes uniform as shown in FIG. 17 showing the state of the surface 16a of the anodized film 16 in FIG. 6 in a plan view.

In the surface smoothing treatment step, the anodized film 16 having the form shown in FIG. 5 is attached to the rotating head 106 toward the polishing pad 104 with respect to the smoothing device 100 shown in FIG. 1 described above.
The type of the polishing pad 104 and the type of the polishing liquid 113 are predetermined according to the anodizing film 16. As the polishing liquid 113, a slurry having an action of etching the anodized film 16 which is an insulating base material can also be used. The slurry that etches the insulating base material is a slurry having a pH range in which the insulating base material is etched. When the insulating base material is alumina, a slurry having a pH of 5.0 or less and a slurry having a pH of 8.0 or more are used. Is.
Further, polishing conditions such as the rotation speed of the rotary surface plate 102, the rotation speed of the rotary head 106, and the pressing force of the anodized film 16 by the rotary head 106 are also predetermined. It is polished and smoothed under polishing conditions (see step S10, FIG. 18).

Immediately after the start of polishing, the sensor 110 senses the anodized film 16 (see step S12, FIG. 18). The sensor 110 measures, for example, the reflectance of the surface 16a of the anodic oxide film 16 which is an insulating base material. In this case, the reflectance in a state where the surface 16a of the anodic oxide film 16 which is the insulating base material and the end surface (not shown) of the conduction path 19 which is the end point is the same surface is measured in advance. Its reflectance represents the end point. Then, the value of the reflectance representing the end point is stored in the control unit 116.
The configuration of the sensor 110 is not particularly limited as long as the reflectance of the surface 16a of the anodized film 16 can be measured, and a known sensor 110 can be appropriately used. Since the end point can be detected in the in situ state, the sensor 110 capable of measuring the reflectance of the surface 16a of the anodized film 16 being polished is preferable.

The reflectance value measured by the sensor 110 is output to the control unit 116 and compared with the reflectance value stored in the control unit 116 as a state of being flush with each other. When the measured reflectance matches the stored reflectance, it is determined that the end point has been detected (see step S14 and FIG. 18).

When the end point is detected in step S14, the smoothing by the smoothing device 100 is stopped by separating the anodized film 16 from the polishing pad 104 or the like.
On the other hand, if the end point is not detected, polishing is continuously performed, and smoothing by polishing (see step S10 and FIG. 18) and sensing (step S12 and FIG. 18) until the end point is detected (see step S14 and FIG. 18). See) is carried out. In this way, the end point is detected, and if the end point is detected, the polishing is automatically stopped.

An allowable range is provided for the coincidence between the measured reflectance value and the reflectance value stored in the control unit 116 as the state of the same surface, and the measured reflectance value is within the allowable range. If they match. The permissible range is, for example, 5% with respect to the reflectance value stored as the state of the same surface.
The reflectance is based on JIS (Japanese Industrial Standards) Z8741: 1997 mirror gloss. As the end point detection for optically detecting the end point, in addition to the reflectance, color may be used as described above. The color is represented by, for example, L ^* a ^* b ^* (JIS (Japanese Industrial Standards) Z8781-4: 2013). When color is used, the color in a state where the surface 16a of the anodic oxide film 16 which is an insulating base material and the end surface (not shown) of the conduction path 19 are the same surface as the reflectance, which is the end point. The taste is measured in advance. The end point is detected using the color that represents the end point.
Further, as described above, the rotation torque acting on the rotation shaft 102a of the rotation platen 102 or the rotation torque acting on the rotation shaft 106a of the rotation head 106 can also be used for the end point detection. Further, the pressing force of the rotating head 106 can be used for detecting the end point.

As described above, in the surface smoothing treatment step, the metal-filled microstructure 13 can be efficiently manufactured because the polishing can be sensed while polishing, the end point can be detected, and the polishing can be automatically stopped when the end point is reached. it can.
If the end point is not detected, or if the end point detection accuracy is low, the end point is not reached, or if polishing is insufficient, the metal-filled microstructure 13 having no conduction path 19 is manufactured. Will be done. On the other hand, when the amount of polishing is large, the metal-filled microstructure 13 having poor quality such as the film thickness of the metal-filled microstructure 13 becomes too thin and the film thickness uniformity of the metal-filled microstructure 13 decreases. It will be manufactured.
The surface smoothing treatment step described above is not limited to detecting the end point by sensing while polishing, that is, detecting the end point in a so-called in situ state, and detecting the end point after temporarily stopping polishing. You may go.

After the surface smoothing treatment step, a part of the surface 16a of the anodized film 16 is removed in the thickness direction D from the state shown in FIGS. 6 and 17, and then, as shown in FIG. 7, the above-mentioned filled metal is removed. May protrude from the surface 16a of the anodized film 16. That is, the conduction path 19 may be projected from the surface 16a of the anodized film 16. The portion where the conduction path 19 protrudes from the surface 16a of the anodized film 16 is referred to as a protruding portion 19a. The step of projecting the filled metal from the surface 16a of the anodizing film 16 is called a metal projecting step.

[Metal protrusion process]
For the partial removal of the above-mentioned anodic oxide film 16, for example, an anodic oxide film 16 that does not dissolve the metal constituting the conduction path 19, that is, an acid aqueous solution or an alkaline aqueous solution that dissolves aluminum oxide is used. A part of the anodized film 16 is removed by bringing the above-mentioned acid aqueous solution or alkaline aqueous solution into contact with the anodized film 16 having a through-passage 17 filled with metal. The method of bringing the above-mentioned acid aqueous solution or alkaline aqueous solution into contact with the anodizing film 16 is not particularly limited, and examples thereof include a dipping method and a spraying method. Of these, the dipping method is preferable.

When an aqueous acid solution is used, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid and hydrochloric acid, or a mixture thereof. Of these, an aqueous solution containing no chromic acid is preferable because it is excellent in safety. The concentration of the aqueous acid solution is preferably 1 to 10% by mass. The temperature of the aqueous acid solution is preferably 25 to 60 ° C.
When an alkaline aqueous solution is used, it is preferable to use at least one alkaline aqueous solution selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. The temperature of the alkaline aqueous solution is preferably 20 to 35 ° C.
Specifically, for example, 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. ..

The immersion time in the acid aqueous solution or the alkaline aqueous solution is preferably 8 to 120 minutes, more preferably 10 to 90 minutes, and further preferably 15 to 60 minutes. Here, the immersion time means the total of each immersion time when the immersion treatment for a short time is repeated. A cleaning treatment may be performed between the immersion treatments.

Further, although the metal is only projected from the surface 16a of the anodic oxide film 16, when the produced metal-filled microstructure 13 is used as an anisotropic conductive member, it is pressure-bonded to an object to be adhered such as a wiring board. For the reason that the properties are good, it is preferable that the metal protrudes from the surface 16a of the anodizing film 16 by 10 nm to 1000 nm, and more preferably 50 nm to 500 nm. That is, the amount of protrusion of the protruding portion 19a from the surface 16a is preferably 10 nm to 1000 nm, more preferably 50 nm to 500 nm.

When strictly controlling the height of the protruding portion 19a of the conduction path 19, after filling the inside of the through-passage 17 with metal, the anodized film 16 and the end portion of the conduction path 19 are made flush with each other. After processing, it is preferable to selectively remove the anodized film. From this as well, as described above, it is important to detect the end point when polishing the anodized film.
Further, after the above-mentioned metal filling or after the metal projecting step, a heat treatment can be performed for the purpose of reducing the distortion in the conduction path 19 generated by the metal filling.
The heat treatment is preferably carried out in a reducing atmosphere from the viewpoint of suppressing the oxidation of the metal. Specifically, the heat treatment is preferably carried out at an oxygen concentration of 20 Pa or less, and more preferably carried out under vacuum. Here, the vacuum refers to a state of space in which at least one of gas density and atmospheric pressure is lower than that of the atmosphere.
Further, the heat treatment is preferably performed while applying stress to the anodized structure 12 for the purpose of straightening.

By using the anodized structure 12 having the support 40 on the anodized film 16, damage to the anodized film 16 can be suppressed as compared with handling the anodized film 16 alone, and the handling is easy. Become.
Here, handling means holding the metal-filled microstructure 13 and moving the metal-filled microstructure 13 for transferring, transporting, and transporting the metal-filled microstructure 13. "Easy to handle" means that damage to the metal-filled microstructure 13 can be suppressed when the metal-filled microstructure 13 is held and when the metal-filled microstructure 13 is moved. Since it is easy to handle, for example, the filled metal is projected from the surface 16a of the anodic oxide film 16, but damage to the metal can be suppressed.

In the metal-filled microstructure 13 shown in FIG. 7, since the filled metal protrudes from the surface 16a of the anodic oxide film 16, it is preferable to protect the protruding metal, that is, the protruding portion 19a of the conduction path 19. Therefore, as shown in FIG. 8, it is preferable to form the resin layer 22 in which the protruding portion 19a of the conduction path 19 is embedded on the surface 16a of the anodized film 16. The step of providing the resin layer 22 is called a resin layer forming step. The method for producing the metal-filled microstructure 13 may include a resin layer forming step.

The resin layer 22 protects the protruding portion 19a of the conduction path 19, the transportability of the metal-filled microstructure 13 can be further improved, and the handling becomes easier. The resin layer 22 has adhesiveness and imparts adhesiveness.
The resin layer 22 can be formed by using, for example, a conventionally known surface protective tape affixing device and a laminator. By providing the resin layer 22, the transportability of the metal-filled microstructure 13 can be improved.

[Resin layer forming process]
Specific examples of the resin material constituting the resin layer 22 include ethylene-based copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin-based resins, acrylic resins, and cellulose-based resins. However, from the viewpoint of transportability and ease of use as an anisotropic conductive member, the above-mentioned resin layer is preferably a film with a peelable adhesive layer, and is adhesive by heat treatment or ultraviolet exposure treatment. It is more preferable that the film has an adhesive layer that is weakened and can be peeled off.

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

Examples of the UV-curable adhesive layer include a polymer in which a carbon-carbon double bond is introduced into the polymer side chain or the main chain or at the end of the main chain as the base polymer. As the base polymer having a carbon-carbon double bond, it is preferable to use an acrylic polymer as a basic skeleton.
Further, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization, if necessary.
The base polymer having a carbon-carbon double bond can be used alone, but UV curable monomers or oligomers can also be blended.
The UV curable adhesive layer is preferably used in combination with a photopolymerization initiator in order to be cured by UV irradiation. Examples of the photopolymerization initiator include benzoin ether compounds; ketal compounds; aromatic sulfonyl chloride compounds; photoactive oxime compounds; benzophenone compounds; thioxanson compounds; camphorquinone; halogenated ketones; acylphosphinoxide; acyls. Phosphonate and the like can be mentioned.

Commercially available products of the heat-release type resin layer include, for example, Intellimar [registered trademark] tapes (manufactured by Nitta Corporation) such as WS5130C02 and WS5130C10; Somatac [registered trademark] TE series (manufactured by Somar Corporation); 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. Riva Alpha [registered trademark] series (manufactured by Nitto Denko KK) such as 3193MS; etc.

Commercially available products of the UV peeling type resin layer include, for example, ELP holders such as ELP DU-300, ELP DU-2385KS, ELP DU-2187G, ELP NBD-3190K, and ELP UE-2091J (Nitto Denko). (Made by Lintec Corporation); Adwill D-210, Adwill D-203, Adwill D-202, Adwill D-175, Adwill D-675 (all manufactured by Lintec Corporation); Sumilite (registered trademark) FLS N8000 series (Sumitomo Bakelite) UC353EP-110 (manufactured by Furukawa Electric Co., Ltd.); and other dicing tapes can be used. Other commercially available products of the UV peeling type resin layer include, for example, ELP RF-7232DB and ELP UB-5133D (all manufactured by Nitto Denko KK); SP-575B-150, SP-541B-205, SP-537T. Back grind tapes such as -160 and SP-537T-230 (both manufactured by Furukawa Electric Co., Ltd.) can be used.
The above-mentioned film with an adhesive layer can be attached using a known surface protective tape affixing device and a laminator.

As a method for forming the resin layer 22, in addition to the above-mentioned method, for example, a resin composition containing an antioxidant material, a polymer material, a solvent (for example, methyl ethyl ketone, etc.) described later is used on the front surface and the back surface of the anodic oxide film 16. In addition, a method of applying to the protruding portion of the conduction path, drying, and firing if necessary can be mentioned.
The coating method of the resin composition is not particularly limited, and for example, a gravure coating method, a reverse coating method, a die coating method, a blade coating method, a roll coating method, an air knife coating method, a screen coating method, a bar coating method, a curtain coating method, etc. Conventionally known coating methods can be used.
The drying method after coating is not particularly limited, and for example, a treatment of heating at a temperature of 0 ° C. to 100 ° C. in the atmosphere for several seconds to several tens of minutes, and a temperature of 0 ° C. to 80 ° C. under reduced pressure. Treatments such as heating for a dozen minutes to several hours can be mentioned.
The firing method after drying is not particularly limited because it differs depending on the polymer material used, but 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 is performed. 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.

Next, the support 40 shown in FIG. 8 is removed from the aluminum base material 14. In this case, the support 40 is removed from the aluminum base material 14 starting from the resin base material 42.
Next, the release layer 24 is laminated on the surface 22a of the resin layer 22. The release layer 24 is a laminate of the support layer 25 and the release agent 26. The release agent 26 is in contact with the resin layer 22. For example, by heating to a predetermined temperature, the adhesive force of the release agent 26 is weakened, and the release layer 24 can be removed.
As the release agent 26, for example, Riva Alpha (registered trademark) manufactured by Nitto Denko Corporation and Somatac (registered trademark) manufactured by SOMAR Corporation can be used.

Next, for example, the support member 30 is attached to the release layer 24 using the double-sided adhesive 28. The support member 30 is arranged to face the support layer 25. The support member 30 has the same outer shape as the anodized structure 12. The support member 30 serves as a support in a subsequent process. By attaching the support member 30, the handleability is increased.
The configuration of the double-sided adhesive 28 is not particularly limited as long as the support layer 25 of the release layer 24 and the support member 30 can be adhered to each other. For example, the double-sided type Riva Alpha manufactured by Nitto Denko Corporation (registered) Trademark) can be used.

The support member 30 supports the metal-filled microstructure 13, and is made of, for example, a silicon substrate. As the support member 30, for example, a ceramic substrate such as SiC, SiC, GaN and alumina (Al ₂ O ₃ ), a glass substrate, a fiber-reinforced plastic substrate, and a metal substrate can be used in addition to the silicon substrate. The fiber reinforced plastic substrate also includes a FR-4 (Flame Retardant Type 4) substrate, which is a printed wiring board.

Next, as shown in FIG. 9, the aluminum base material 14 is dissolved and removed, for example, to expose the back surface 16b of the anodic oxide film 16. For the dissolution of the aluminum base material 14, it is preferable to use a treatment liquid in which the anodized film 16 is difficult to dissolve and aluminum is easily dissolved.
If the aluminum base material 14 can be removed without damaging the anodic oxide film 16, it is not limited to dissolution. Removing the aluminum base material 14 is called a substrate removing step.

[Substrate removal process]
The treatment liquid for dissolving the aluminum base material 14 preferably has a dissolution rate in aluminum of 1 μm / min or more, more preferably 3 μm / min or more, and further preferably 5 μm / min or more. Similarly, the dissolution rate for the anodic oxide film is preferably 0.1 nm / min or less, more preferably 0.05 nm / min or less, and further preferably 0.01 nm / min or less.

Specifically, it is preferably a treatment liquid containing at least one metal compound having a lower ionization tendency than aluminum and having a pH (hydrogen ion index) of 4 or less or 8 or more, and the pH is 3 or less or It is more preferably 9 or more, and further preferably 2 or less or 10 or more.
Such treatment solutions are based on an acid or alkaline aqueous solution and include, for example, manganese, zinc, chromium, iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper, mercury, silver, palladium, platinum, etc. It is preferable that a gold compound (for example, chloroplatinic acid), these fluorides, these chlorides and the like are blended.
Of these, an acid aqueous solution base is preferable, and a chloride blend is preferable.
In particular, a treatment liquid obtained by blending a hydrochloric acid aqueous solution with mercury chloride (hydrochloric acid / mercury chloride) and a treatment liquid obtained by blending a hydrochloric acid aqueous solution with copper chloride (hydrochloric acid / copper chloride) are preferable from the viewpoint of treatment latitude.
The composition of such a treatment liquid is not particularly limited, and for example, a bromine / methanol mixture, a bromine / ethanol mixture, aqua regia, or the like can be used.

The acid or alkali concentration of such a treatment liquid is preferably 0.01 to 10 mol / L, more preferably 0.05 to 5 mol / L.
Further, the treatment temperature using such a treatment liquid is preferably −10 ° C. to 80 ° C., preferably 0 ° C. to 60 ° C.

Further, the above-mentioned aluminum base material 14 is dissolved by bringing the above-mentioned aluminum base material 14 after the metal filling step into contact with the above-mentioned treatment liquid. The contact method is not particularly limited, and examples thereof include a dipping method and a spraying method. Above all, the dipping method is preferable. The contact time at this time is preferably 10 seconds to 5 hours, more preferably 1 minute to 3 hours.

Next, as shown in FIG. 10, the back surface 16b of the anodized film 16 is polished. In polishing 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 conduction path 19 are flattened to the same surface. Since the polishing of the back surface 16b of the anodized film 16 described above is the same as the surface smoothing treatment step for the surface 16a of the anodized film 16 shown in FIG. 6, a detailed description thereof will be omitted.

As described above, after performing the surface smoothing treatment step on the surface 16a of the anodized film 16 having the plurality of conduction paths 19, the surface of the back surface 16b of the anodized film 16 having the plurality of conduction paths 19 Although the smoothing treatment step has been carried out, the above-mentioned surface smoothing treatment step may be carried out on at least one surface.
For example, the reflectance of the front surface 16a and the back surface 16b of the anodized film 16 is measured using the sensor 110, respectively, and if the reflectance value is within a predetermined range, the process can be carried out in the next step without polishing. You may want to migrate.

Next, as shown in FIG. 11, the back surface 16b of the anodized film 16 is partially removed in the thickness direction D, and the filled metal is projected from the back surface 16b of the anodized film 16. That is, the conduction path 19 is projected from the back surface 16b of the anodized film 16. The portion where the conduction path 19 protrudes from the back surface 16b of the anodized film 16 is referred to as a protruding portion 19b.
Since the step of projecting the filled metal from the back surface 16b of the anodizing film 16 is the same as the above-mentioned metal projecting step, detailed description thereof will be omitted.

Next, as shown in FIG. 12, a resin layer 22 in which the protruding portion 19b of the conduction path 19 of the back surface 16b of the anodizing film 16 is embedded is formed on the back surface 16b of the anodizing film 16. As a result, the anisotropic conductive material 32 using the metal-filled microstructure 13 can be obtained. If the shape of the anisotropic conductive material 32 is, for example, a disk shape, an apparatus used for transporting a semiconductor wafer or the like can be used for transporting the anisotropic conductive material 32, and the anisotropic conductive material 32 can be transported. No special equipment is required for handling.
Since the method of forming the resin layer 22 in which the protruding portion 19b of the conduction path 19 is embedded is the same as the above-described resin layer forming step, detailed description thereof will be omitted.

FIG. 13 is a plan view showing an example of the configuration of the metal-filled microstructure according to the embodiment of the present invention, and FIG. 14 is a schematic cross-sectional view showing an example of the configuration of the metal-filled microstructure according to the embodiment of the present invention. is there. FIG. 14 is a cross-sectional view taken along the line IB-IB of FIG.

In the metal-filled microstructure 13 shown in FIGS. 13 and 14, as described above, the anodic oxide film 16 which is an insulating base material, the through-passage 17 penetrating the anodized film 16 in the thickness direction D, and the through-passage 17 It has a plurality of conduction paths 19 made of metal filled inside the above. The plurality of conduction paths 19 are provided in a state of being electrically insulated from each other. Further, for example, the resin layer 22 provided on the front surface 16a and the back surface 16b of the anodizing film 16 is provided.
Here, the "state of being electrically insulated from each other" means that the conduction paths 19 existing inside the anodized film 16 are sufficiently low in conductivity with each other inside the anodized film 16. Means.
In the metal-filled microstructure 13, the conduction paths 19 are electrically insulated from each other, the conductivity is sufficiently low in the direction x orthogonal to the thickness direction D of the anodic oxide film 16, and the conductivity is provided in the thickness direction D. It is a member having orthogonal conductivity. The metal-filled microstructure 13 is arranged so that the thickness direction D coincides with, for example, the stacking direction of the electronic elements 35 described later.
As shown in FIGS. 13 and 14, the conduction path 19 is provided so as to penetrate the anodized film 16 in the thickness direction D in a state of being electrically insulated from each other.

The thickness h of the metal-filled microstructure 13 is, for example, 30 μm or less. Further, the metal-filled microstructure 13 preferably has a TTV (Total Thickness Variation) of 10 μm or less. Since the front surface 16a and the back surface 16b of the anodized film 16 are polished, the thickness of the anodized film 16 is thicker than the thickness h of the metal-filled microstructure 13, for example, it exceeds 30 μm, but is preferably about 40 μm from the viewpoint of brittleness.

Here, the thickness h of the metal-filled microstructure 13 and the thickness of the anodized film 16 are the focused ion beams (FIB) of the metal-filled microstructure 13 and the anodized film 16 in the thickness direction, respectively. ), And the cross section is observed with an electro-emission scanning electron microscope at a magnification of 200,000 times, and the contour shapes of the metal-filled microstructure 13 and the anodized film 16 are obtained, respectively, and correspond to the thickness h. It is the average value measured at 10 points in the area to be measured.
Further, the TTV (Total Thickness Variation) of the metal-filled microstructure 13 is a value obtained by cutting the metal-filled microstructure 13 together with the support member 30 by dicing and observing the cross-sectional shape of the metal-filled microstructure 13. is there.

The metal-filled microstructure 13 can be used, for example, as an anisotropic conductive member exhibiting anisotropic conductivity. In this case, as shown in FIG. 15, an electronic element 35 in which the semiconductor chip 36 and the semiconductor chip 37 are joined via a metal-filled microstructure 13 to electrically connect the semiconductor chip 36 and the semiconductor chip 37. Can be obtained. In the electronic device 35, the metal-filled microstructure 13 functions as a TSV (Through Silicon Via).
In addition to this, an electronic element in which three or more semiconductor chips are electrically connected by using the metal-filled microstructure 13 can also be used. Three-dimensional mounting is possible by using the metal-filled microstructure 13. The number of semiconductor chips to be bonded is not particularly limited, and is appropriately determined according to the function of the electronic device and the performance required for the electronic device.

By using the metal-filled microstructure 13, the size of the electronic element can be reduced and the mounting area can be reduced. Further, by shortening the thickness of the metal-filled microstructure 13, the wiring length between the semiconductor chips can be shortened, the signal delay can be suppressed, and the processing speed of the electronic element can be improved. Power consumption can also be suppressed by shortening the wiring length between semiconductor chips.
Since the metal-filled microstructure 13 is polished so that the anodized film 16 and the conduction path 19 are flush with each other on the surface 16a of the anodized film 16 as described above, the shape accuracy is high. Further, since the height of the protruding portion 19a of the conduction path 19 can be strictly controlled as described above, the reliability of the electrical connection between the semiconductor chip 36 and the semiconductor chip 37 is excellent.

The semiconductor chip 36 and the semiconductor chip 37 have an element region. The element region is an region in which various element constituent circuits and the like for functioning as an electronic element are formed. In the element area, for example, a memory circuit such as a flash memory, an area in which a microprocessor and a logic circuit such as an FPGA (field-programmable gate array) are formed, a communication module such as a wireless tag, and wiring are formed. There is an area. In addition to this, MEMS (Micro Electro Mechanical Systems) may be formed in the element region. MEMS is, for example, a sensor, an actuator, an antenna, or the like. Sensors include, for example, various sensors such as acceleration, sound, and light.

The semiconductor chip 36 and the semiconductor chip 37 are appropriately selected according to the function achieved by the electronic element 35. For example, in the electronic element 35 shown in FIG. 15, a semiconductor chip 36 having a logic circuit and a semiconductor chip 37 having a memory circuit can be combined. Further, the combination of the semiconductor chips in the electronic element 35 may be a combination of a sensor, an actuator, an antenna, or the like, a memory circuit, and a logic circuit.
The semiconductor chip 36 and the semiconductor chip 37 are composed of, for example, silicon, but are not limited to this, and may be silicon carbide, germanium, gallium arsenide, gallium nitride, or the like.
Further, in addition to the semiconductor chip 36 and the semiconductor chip 37, the two wiring layers may be electrically connected by using the metal-filled microstructure 13.

Hereinafter, the configurations of the metal-filled microstructure 13 and the anisotropic conductive material 32 will be described more specifically.
[Anodized film]
The anodic oxide film 16 functions as an insulating base material. The distance between the conduction paths in the anodized film 16 is preferably 5 nm to 800 nm, more preferably 10 nm to 200 nm, and even more preferably 20 nm to 60 nm. When the distance between the conduction paths in the anodic oxide film 16 is within this range, the anodic oxide film 16 sufficiently functions as an insulating partition wall.
Here, the distance between the conduction paths refers to the width w between the adjacent conduction paths, and the cross section of the metal-filled microstructure 13 is observed with a field emission scanning electron microscope at a magnification of 200,000 times and adjacent to each other. The average value of the width between conduction paths measured at 10 points.

[Conduction path]
As described above, the plurality of conduction paths 19 penetrate in the thickness direction of the anodizing film 16 and are provided in a state of being electrically insulated from each other, and are columnar. The conduction path 19 may be made of metal and have projecting portions protruding from the front surface and the back surface of the anodizing film 16, and the projecting portions of each conduction path may be embedded in the resin layer.
The area ratio of the conduction path 19 with respect to the surface of the insulating base material, that is, the surface of the anodic oxide film 16, is 15% or more and 50% or less.
Further, the conduction path 19 has a diameter d of 20 nm or more and 110 nm or less. The diameter d of the conduction path 19 corresponds to the inner diameter of the gangway 17.
When the area ratio of the conduction path 19 is less than 15%, no change is observed even if the area other than the conduction path 19 is large and the surface of the conduction path 19 appears. Further, when the area ratio of the conduction path 19 exceeds 50%, on the contrary, even if the area of the conduction path 19 is large and the surface of the conduction path 19 appears, no change is observed.
When the diameter of the conduction path 19 is also less than 20 nm, the area other than the conduction path 19 is large and no change is observed even if the surface of the conduction path 19 appears. Further, when the diameter of the conduction path 19 exceeds 110 nm, on the contrary, even if the area of the conduction path 1 is large and the surface of the conduction path 19 appears, no change is observed.

The area ratio of the conduction path 19 can be obtained as follows. First, an image of the anodized film 16 including the conduction path 19 as shown in FIG. 13 is acquired from the surface 16a side of the anodized film 16. Subsequently, the outline of the conduction path 19 is extracted from the image, and the area of the conduction path 19 is obtained. This is performed for the conduction path 19 to obtain the total area of the conduction path 19. The area ratio of the conduction path 19 is obtained by using the area of the anodized film 16 and the total area of the conduction path 19.
Incidentally, when the area of the anodic oxide film 16 and _{D 1,} a total area of the conductive paths 19 and _{D 2,} the area ratio of the conductive paths 19 and _{R 1,} the area ratio _{R 1} of the conductive paths 19, R1 = D It is represented by ₂ / D ₁ .

<Protruding part>
The protruding portions 19a and 19b of the conduction path 19 are portions where the conduction path 19 protrudes from the front surface 16a and the back surface 16b of the anodized film 16, and are preferably protected by the resin layer 22.
When the metal-filled microstructure 13 is used as an anisotropic conductive member, and the protruding portion is crushed when the anisotropic conductive member and the electrode are electrically connected or physically joined by a method such as crimping. The aspect ratio (height of the protruding portion / diameter of the protruding portion) of the protruding portion of the conduction path is preferably 0.5 or more and less than 50, preferably 0.8, for the reason that sufficient insulation in the plane direction can be ensured. It is more preferably ~ 20, and even more preferably 1-10.

Further, from the viewpoint of following the surface shape of the semiconductor chip or semiconductor wafer to be connected, the height of the protruding portion of the conduction path is preferably 20 nm or more, more preferably 100 nm to 500 nm.
The height of the protruding portion of the conduction path is the average obtained by observing the cross section of the heterogeneous conductive member with a field emission scanning electron microscope at a magnification of 20,000 times and measuring the height of the protruding portion of the conduction path at 10 points. The value.
The diameter of the protruding portion of the conduction path is an average value obtained by observing the cross section of the anisotropic conductive member with a field emission scanning electron microscope and measuring the diameter of the protruding portion of the conduction path at 10 points.

<Other shapes>
Density of the conductive paths 19, is preferably 20,000 / mm ² or more, more preferably 2,000,000 / mm ² or more, still more preferably 10,000,000 / mm ² or more, 50 million The number of pieces / mm ² or more is particularly preferable, and the number of pieces / mm ² or more is most preferable.
Further, the center-to-center distance p (see FIGS. 13 and 14) of each of the adjacent conduction paths 19 is preferably 20 nm to 500 nm, more preferably 40 nm to 200 nm, and further preferably 50 nm to 140 nm. preferable.

[Resin layer]
As described above, the resin layer 22 is provided on the front surface 16a and the back surface 16b of the anodized film 16, and the protruding portions 19a and 19b of the conduction path 19 are embedded as described above. That is, the resin layer 22 covers the end of the conduction path 19 protruding from the anodized film 16 and protects the protruding portions 19a and 19b.
The resin layer 22 is formed by the above-mentioned resin layer forming step. The resin layer 22 imparts adhesiveness to the connection target. The resin layer 22 preferably exhibits fluidity in the temperature range of 50 ° C. to 200 ° C. and cures at 200 ° C. or higher.
The resin layer 22 is formed by the above-mentioned resin layer forming step, but the composition of the resin layer shown below can also be used. Hereinafter, the composition of the resin layer will be described. For example, the resin layer contains a polymer material and may contain an antioxidant material.

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

<Antioxidant material>
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-tetrazol-5-acetic acid, 1H-tetrazole-5-succinic acid, 1,2,3-triazole, 4-amino-1,2,3-triazole, 4,5-diamino-1 , 2,3-Triazole, 4-carboxy-1H-1,2,3-Triazole, 4,5-Dicarboxy-1H-1,2,3-Triazole, 1H-1,2,3-Triazole-4- Acetic acid, 4-carboxy-5-carboxymethyl-1H-1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2 , 4-triazole, 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, benzofloxane, 2,1,3-benzothiazole, o-phenylenediamine, m-phenylenediamine, catechol, o-aminophenol, 2-mercaptobenzothiazole, 2-mercaptobenzoimidazole , 2-Mercaptobenzoxazole, melamine, and derivatives thereof.
Of these, benzotriazole and its derivatives are preferred.
The benzotriazole derivative includes a hydroxyl group, an alkoxy group (for example, methoxy group, ethoxy group, etc.), an amino group, a nitro group, and an alkyl group (for example, a methyl group, an ethyl group, a butyl group, etc.) on the benzene ring of benzotriazole. , Substituent benzotriazole having a halogen atom (for example, fluorine, chlorine, bromine, iodine, etc.) and the like. In addition, naphthalene triazole, naphthalene bistriazole, substituted naphthalene triazole substituted, substituted naphthalene bistriazole and the like can also be mentioned.

In addition, as another example of the antioxidant material contained in the resin layer, general antioxidants such as higher fatty acid, higher fatty acid copper, phenol compound, alkanolamine, hydroquinone, copper chelating agent, organic amine, and organic Examples include ammonium salts.

The content of the antioxidant material contained in the resin layer is not particularly limited, but from the viewpoint of the anticorrosive effect, 0.0001% by mass or more is preferable, and 0.001% by mass or more is more preferable with respect to the total mass of the resin layer. Further, 5.0% by mass or less is preferable, and 2.5% by mass or less is more preferable, for the reason of obtaining an appropriate electric resistance in this joining process.

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

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

(Inorganic ion exchanger)
Examples of the inorganic ion exchanger include hydrous oxides of metals typified by zirconium hydroxide.
As the type of metal, for example, in addition to zirconium, iron, aluminum, tin, titanium, antimony, magnesium, beryllium, indium, chromium, bismuth and the like are known.
Of these, the zirconium-based one has the ability to exchange the cations Cu ²⁺ and Al ³⁺ . In addition, iron-based products also have exchangeability for Ag ⁺ and Cu ²⁺ . Similarly, tin-based, titanium-based, and antimony-based ones are cation exchangers.
On the other hand, those of bismuth-based, anion Cl ^- has exchange capacity for.
In addition, zirconium-based products show anion exchange ability depending on the manufacturing conditions. The same applies to aluminum-based and tin-based ones.
As other inorganic ion exchangers, compounds such as acid salts of polyvalent metals typified by zirconium phosphate, heteropolylates typified by ammonium molybdrinate, and insoluble ferrocyanides are known.
Some of these inorganic ion exchangers are already on the market, and for example, various grades under the trade name IXE of Toagosei Co., Ltd. are known.
In addition to synthetic products, natural zeolite or inorganic ion exchanger powder such as montmorillonite can also be used.

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

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

Further, the mixing ratio of the migration prevention material and the above-mentioned polymer material is preferably 10% by mass or less for the migration prevention material and 5% by mass or less for the migration prevention material, for example, from the viewpoint of mechanical strength. It is more preferable, and it is further preferable that the migration prevention material is 2.5% by mass or less. Further, from the viewpoint of suppressing migration when the semiconductor chip or semiconductor wafer is bonded to the anisotropic conductive member, the migration prevention material is preferably 0.01% by mass or more.

<Inorganic filler>
The resin layer may contain an inorganic filler.
The inorganic filler is not particularly limited and may be appropriately selected from known ones. For example, kaolin, barium sulfate, barium titanate, silicon oxide powder, fine powdered silicon oxide, vapor phase silica, amorphous silica. , Crystalline silica, molten silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, aluminum nitride, zirconium oxide, yttrium oxide, silicon carbide, silicon nitride and the like.

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

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

Specific examples of the curing agent include aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives such as 4-methylimidazole, dicyandiamide, tetramethylguanidine, thiourea-added amine, and methyl. Examples thereof include carboxylic acid anhydrides such as hexahydrophthalic anhydride, carboxylic acid hydrazide, carboxylic acid amides, polyphenol compounds, novolak resins, and polymercaptans, and from these curing agents, those liquid at 25 ° C. are appropriately selected. Can be used. The curing agent may be used alone or in combination of two or more.

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

<Shape>
For the reason of protecting the conduction path 19 of the metal-filled microstructure 13, the thickness of the resin layer is preferably larger than the height of the protruding portions 19a and 19b of the conduction path 19 and is 1 μm to 5 μm.

The present invention is basically configured as described above. Although the method for producing the metal-filled microstructure of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements or modifications have been made without departing from the gist of the present invention. Of course, it is also good.

The features of the present invention will be described in more detail with reference to Examples below. The materials, reagents, amounts of substances used, amounts of substances, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below.
In this example, the metal-filled microstructures shown in Examples 1 to 5 and Comparative Examples 1 and 2 were subjected to surface smoothing treatment to detect the end point. The configurations of Examples 1 to 5 and Comparative Examples 1 and 2, the slurry used, and the end point detection results are shown in Table 1 below.
Next, Examples 1 to 5 and Comparative Examples 1 and 2 will be described.

(Example 1)
(A) Mirror finish treatment (electropolishing treatment)
A high-purity aluminum substrate (manufactured by Sumitomo Light Metal Industries, Ltd., purity 99.99% by mass, thickness 0.1 mm) is cut into an area of 50 cm square so that it can be anodized. The electrolytic polishing treatment was performed under the conditions of a temperature of 65 ° C. and a liquid flow velocity of 3.0 m / min.
A carbon electrode was used as the cathode, and GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.) was used as the power source. The flow velocity of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

(Electropolishing liquid composition)
・ 85 mass% phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 55 vol%
・ Sulfuric acid 1.5 vol%
・ Ethylene glycol 0.5 vol%

(B) Anodizing treatment (self-regularization method I)
Next, the aluminum substrate after the electrolytic polishing treatment was subjected to pre-anodination treatment for 14 hours with an electrolytic solution of 0.30 mol / L sulfuric acid under the conditions of a voltage of 25 V, a liquid temperature of 10 ° C., and a liquid flow rate of 3.0 m / min. did.
Then, the pre-anodized aluminum substrate was subjected to a film removal treatment by immersing it in a mixed aqueous solution of 0.2 mol / L chromic anhydride and 0.6 mol / L phosphoric acid (liquid temperature: 50 ° C.) for 14 hours.
Then, a reanodizing treatment was carried out with an electrolytic solution of 0.30 mol / L sulfuric acid for 1 hour under the conditions of a voltage of 25 V, a liquid temperature of 10 ° C., and a liquid flow rate of 3.0 m / min.
In both the pre-anodizing treatment and the re-anodizing treatment, the cathode was a stainless steel electrode, and the power source was GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.). A NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) was used as a cooling device, and a pair stirrer PS-100 (manufactured by EYELA) was used as a stirring and heating device. Further, the flow velocity of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

(C) Aluminum Removal Treatment Next, the aluminum substrate was dissolved by immersing it in a 20 mass% mercury chloride aqueous solution (rise) at 20 ° C. for 3 hours.

(D) Heat Treatment Next, the obtained structure was heat-treated at a temperature of 400 ° C. for 1 hour.

(E) Photosensitive layer coating treatment Next, a coating liquid A for a photosensitive layer having the following composition is applied to the surface of the obtained structure from which aluminum has been removed with a wire bar, and then in a drying oven at 140 ° C. for 50 seconds. After drying, the coating amount was 0.85 g / m ² .

(Coating liquid A for photosensitive layer)
0.45 g of an esterified product of naphthoquinone-1,2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709).
N- (4-Aminosulfonylphenyl) methacrylamide / methyl methacrylate (molar ratio 34:66, weight average molecular weight 51,000) 1.10 g
-2- (P-Methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine
0.02g
・ Tetrahydrophthalic anhydride 0.05g
・ Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.01g
・ Megafuck F-177 (Fluorine-based surfactant manufactured by Dainippon Ink and Chemicals Co., Ltd.)
0.006g
・ Pluronic F-108 (Polyoxyethylene polyoxypropylene block polymer manufactured by Asahi Denka Corporation) 0.02 g
・ Methyl ethyl ketone 10g
・ 1-methoxy-2-propanol 10 g

By this method, a metal finely packed structure having an area ratio of 30% of the conduction path and a diameter of 50 nm of the conduction path was obtained.

(F) Metal Filling Treatment Next, the gold electrode was brought into close contact with the pattern forming side of the structure after the heat treatment by gold vapor deposition, and electrolytic plating was performed using the gold electrode as a cathode and copper as a positive electrode.
A mixed solution of copper sulfate = 200/50/15 (g / L) was used as an electrolytic solution while being kept at 25 ° C., and constant voltage pulse electrolysis was performed to fill the micropore through holes with copper. A microstructure was manufactured.
Here, for constant voltage pulse electrolysis, a plating apparatus manufactured by Yamamoto Plating Co., Ltd. was used, and a power source (HZ-3000) manufactured by Hokuto Denko Co., Ltd. was used to perform cyclic voltammetry in the plating solution to confirm the precipitation potential. After that, the potential on the film side was set to -2V. The pulse waveform of the constant voltage pulse electrolysis was a square wave. Specifically, the electrolysis treatment with a single electrolysis time of 60 seconds was performed five times with a pause time of 40 seconds between each electrolysis treatment so that the total electrolysis treatment time was 300 seconds.

(G) Surface Smoothing Treatment Next, the surface of the copper-filled structure was subjected to a CMP (Chemical Mechanical Polishing) treatment.
As the CMP slurry, a slurry containing 10% by mass of alumina using water as a solvent was adjusted to pH 4.00 with hydrochloric acid and used. A champ manufactured by Tokyo Seimitsu Co., Ltd. was used as the polishing device, and a reflected light measuring device was used to detect the end point. Polishing was performed with a polishing pressure of 20.68 kPa (3.0 psi (pound-force per square inch)).

In Example 1, the end point was detected by using the reflected light as the detection method for the end point detection.
The evaluation of the end point detection using the reflected light was performed as follows.
As a reference sample, the copper-filled structure used in Example 1 was polished at the same polishing pressure for 10 minutes, and a sample confirmed that the final film thickness was about 2/3 of the initial film thickness was used. ..
The reflected light measuring device used for the end point detection was incorporated in the polishing device, and the determination was made by matching the reflected light spectra. White light was used as a light source, and several points on the substrate were used for inspection.
A: Since the reflectance was 90% to 110% of the reflectance of the reference sample in the entire region of the observation wavelength (visible region), the end point could be detected.
B: The end point could not be detected because there was a region where the reflectance was less than 90% or more than 110% of the reflectance of the reference sample in at least a part region of the observation wavelength.

(Example 2)
In Example 2, as compared with Example 1, a slurry containing 10% by mass of alumina using water as a solvent was used as a slurry whose pH was adjusted to 9.00 using ammonia. Same as.
(Example 3)
In Example 3, as compared with Example 1, a slurry containing 10% by mass of silica using water as a solvent was used and adjusted to pH 2.20 with citric acid, and the end point was detected. It was the same as in Example 1 except that the detection method was torque current.
The evaluation of the end point detection using the torque current was performed as follows.
A: The torque current increased once, then decreased as the polishing progressed, and finally reached a constant value, so that the end point could be detected.
B: The torque current remained increased, and no decrease was observed with the progress of polishing, so that the end point could not be detected.

(Example 4)
In Example 4, as compared with Example 1, the area ratio of the conduction path was 40% and the diameter of the conduction path was 40 nm, and KOH was added to the slurry containing 10% by mass of silica using water as a solvent. It was the same as in Example 1 except that the slurry adjusted to pH 9.80 was used and the detection method for detecting the end point was torque current. The area ratio of the conduction path and the diameter of the conduction path were adjusted by changing the voltage, liquid temperature, and flow velocity for forming the micropore through hole.
(Example 5)
In Example 5, as compared with Example 1, the area ratio of the conduction path was 50% and the diameter of the conduction path was 20 nm, and the slurry contained 10% by mass of silica using water as a solvent was ammonia. The same as in Example 1 except that the slurry adjusted to pH 8.50 was used. The area ratio of the conduction path and the diameter of the conduction path were adjusted by changing the voltage, liquid temperature, and flow velocity for forming the micropore through hole.

(Comparative Example 1)
Comparative Example 1 was the same as that of Example 1 except that the area ratio of the conduction path was 10% as compared with Example 1. The area ratio of the conduction path was adjusted by changing the voltage, liquid temperature, and flow velocity for forming the micropore through hole.
(Comparative Example 2)
Comparative Example 2 was the same as that of Example 1 except that the area ratio of the conduction path was 50% and the diameter of the conduction path was 10 nm as compared with Example 1. The area ratio of the conduction path was adjusted by changing the voltage, liquid temperature, and flow velocity for forming the micropore through hole.

As shown in Table 1, in Examples 1 to 5, the end point could be detected when the metal-filled microstructure was smoothed. On the other hand, in Comparative Examples 1 and 2, the end point could not be detected when the metal-filled microstructure was smoothed. The slurries of Examples 1 to 5 are all slurries having an action of etching an insulating base material.

10 Aluminum substrate 10a Surface 12 Anodized structure 13 Metal-filled microstructure 14 Aluminum base material 14a, 16a, 22a Surface 14b, 16b Back surface 16 Anodized film 16c Surface 17 Penetration path 19 Conductive path 19a Protruding part 19b Protruding part 19c End face 20 Part 21 Part 22 Resin layer 24 Peeling layer 25 Supporting layer 26 Peeling agent 28 Double-sided adhesive 30 Supporting member 32 Gross conductive material 35 Electronic element 36, 37 Semiconductor chip 40 Support 42 Resin base material 100 Smoothing device 102 Rotational surface plate Panel 102a, 106a Rotating shaft 104 Polishing pad 106 Rotating head 108 Motor 110 Sensor 112 Adjusting unit 113 Polishing liquid 114 Supply unit 116 Control unit D Thickness direction d Diameter h Thickness p Center distance S10 step S12 step S14 step W Polished body w Width x direction

Claims (8)

A metal-filled microstructure having an insulating base material, a plurality of through-passages penetrating in the thickness direction of the insulating base material, and a plurality of conduction paths made of metal filled inside the through-passages. It ’s a manufacturing method,
The area ratio of the conduction path to the surface of the insulating base material is 15% or more and 50% or less, and the diameter of the conduction path is 20 nm or more and 110 nm or less.
A surface smoothing treatment step of flattening at least one surface of the insulating base material whose through- pass is filled with the metal until the conduction path and the insulating base material are flush with each other. Have and
The surface smoothing treatment step is a method for manufacturing a metal-filled microstructure that stops by detecting the end point by optically detecting the end point. A metal-filled microstructure having an insulating base material, a plurality of through-passages penetrating in the thickness direction of the insulating base material, and a plurality of conduction paths made of metal filled inside the through-passages. It ’s a manufacturing method,
The area ratio of the conduction path to the surface of the insulating base material is 15% or more and 50% or less, and the diameter of the conduction path is 20 nm or more and 110 nm or less.
A surface smoothing treatment step of flattening at least one surface of the insulating base material in which the through path is filled with the metal until the conduction path and the insulating base material are in the same surface state. Have and
The surface smoothing treatment step stops after detecting the end point, which electrically detects the end point .
Chemical mechanical polishing is used for the smoothing of the surface smoothing treatment step, and the end point detection for electrically detecting the end point is the polishing body used for the chemical mechanical polishing and the insulating group. A method for manufacturing a metal-filled microstructure using a rotational torque that represents the frictional force between the material and at least one surface . The method for producing a metal-filled microstructure according to claim 1 or 2 , wherein the surface smoothing treatment step is performed on both surfaces of the insulating base material whose through-passage is filled with the metal. The metal according to any one of claims 1 to 3 , wherein the end point detection detects a state in which the surface of the insulating base material and the end surface of the conduction path have a surface roughness of 20 nm or less as the end point. A method for manufacturing a filled microstructure. The method for producing a metal-filled microstructure according to claim 1 , 3, or 4 , wherein the smoothing of the surface smoothing treatment step uses chemical mechanical polishing, dry etching, or grinding. The method for producing a metal-filled microstructure according to claim 5 , wherein the chemical mechanical polishing uses a slurry having an action of etching the insulating base material. The method for producing a metal-filled microstructure according to claim 1 , wherein the end point detection for optically detecting the end point uses the reflectance of the insulating base material. The method for producing a metal-filled microstructure according to any one of claims 1 to 7 , wherein the surface smoothing treatment step performs the smoothing and detects the end point during the smoothing.