This application is related to and claims priority under 35 U.S.C. 119 to Japanese patent application No. 2019-184835, filed on Oct. 7, 2019.
An embodiment of the present invention relates to a holding apparatus for applying an electrolytic plating treatment to a planar workpiece disposed between a rear member and a front member facing the rear member and having an opening part.
Upon applying an electrolytic plating treatment to a planar workpiece, a holding apparatus for fixing the planar workpiece is used, for example. The planar workpiece that is fixed to the holding apparatus is immersed in a liquid bath in a manner that the planar workpiece and an anode electrode are disposed to face one another. An electric current is then provided between the planar workpiece and the anode electrode to perform the electrolytic plating treatment. The holding apparatus for fixing the planar workpiece has, for example, a rear member and a front member facing the rear member and having an opening part. The planar workpiece is disposed between the rear member and the front member.
A plating film formed by an electrolytic plating treatment is required to have a uniform thickness. However, a thickness of a plating film is susceptible to electric field distribution between a planar workpiece and an anode electrode. In particular, a thickness of a plating film around a cathode electrode, which is in contact with the planar workpiece, tends to be larger than the other parts of the planar workpiece. A known method for achieving a uniform thickness of a plating film is to dispose a shielding plate between a planar workpiece and an anode electrode for a purpose of controlling a flow of an electric current to generate uniform electric field distribution.
JP-A-2002-161398 discloses a substrate holder with a shielding plate. This substrate holder has a front pressing plate and a rear pressing plate that can be swung with ease. In addition to providing the substrate holder with the shielding plate, the front and rear pressing plates are formed from a non-conductive resin, and in these pressing plates, a conducting bar is embedded. The substrate holder also has electric current-transmitting pins that are connected to the conducting bar and provided in the front and rear pressing plates in a manner that one electric current-transmitting pin contacts another electric current-transmitting pin on inner contact surfaces of the front and rear pressing plates. In addition, the substrate holder has a mechanism for clamping the front and rear pressing plates together.
The substrate holder with the shielding plate in JP-A-2002-161398 enables a thickness of a plating film to become uniform but allows an edge part of a planar workpiece to be plated in some cases.
The present invention has been accomplished considering the above circumstances, and an object of the present invention is to provide a holding apparatus for applying an electrolytic plating treatment to a planar workpiece. The holding apparatus can reduce an amount of plating that is deposited on an edge part of the planar workpiece. Another object of the present invention is to provide a method for applying an electrolytic plating treatment to a planar workpiece with the holding apparatus.
An embodiment of the present invention includes the followings.
In the holding apparatus according to the present invention, the plurality of electrodes and the plurality of first insulating parts cover a predetermined range of the edge part of the planar workpiece in the width direction of the planar workpiece when the planar workpiece is disposed between the rear member and the front member. This cover enables proper control of a flow of an electric current and then uniform electric field distribution, thus rendering the electric current less likely to flow into the edge part of the planar workpiece. As a result, even though an electrolytic plating treatment is applied to the planar workpiece, an amount of plating that is deposited on the edge part of the planar workpiece can be reduced.
A holding apparatus according to the present invention is for applying an electrolytic plating treatment to a planar workpiece. The holding apparatus has a rear member and a front member facing the rear member and having an opening part. The planar workpiece is disposed between the rear member and the front member. The front member has a plurality of electrodes and a plurality of first insulating parts. The plurality of electrodes and the plurality of first insulating parts cover an edge part of the planar workpiece in a width direction of the planar workpiece. Provided that an edge length of the planar workpiece in the width direction of the planar workpiece or an edge length of the opening part in a direction parallel to the width direction of the planar workpiece, whichever is smaller, is defined as 100, an edge part-covering length of the plurality of electrodes or the plurality of first insulating parts is 80 or more in the width direction of the planar workpiece within the edge length of the planar workpiece in the width direction of the planar workpiece.
Hereinbelow is concretely described the holding apparatus according to an embodiment of the present invention with reference to the drawings. An embodiment of the present invention is, however, not limited to the illustrated examples and can be put into practice after appropriate modifications within a range meeting the gist of the above and the below. All of these are included in the technical scope of an embodiment of the present invention.
The front member 13 of the holding apparatus 1 has the plurality of electrodes and the plurality of first insulating parts. The plurality of electrodes and the plurality of first insulating parts cover the edge part of the planar workpiece in the width direction of the planar workpiece. Each of the electrodes is connected to a wire and a power source, and can transmit an electric current to the planar workpiece when coming into contact with the planar workpiece. Each of the first insulating parts shields the edge part of the planar workpiece in such a manner as to prevent the electric current from flowing into the edge part. Forming the first insulating parts on the front member can lead to reduction in an amount of plating that is deposited on the edge part of the planar workpiece.
The number of the electrodes merely needs to be plural, namely 2 or more, and is not particularly limited thereto. The number may be determined based upon sizes of the holding apparatus 1 and the planar workpiece, electric field distribution, or the like. A larger number of the electrodes can prevent a concentration of electric currents to a greater degree, thus being able to achieve a uniform thickness of a plating film. The number of the electrodes is preferably 4 or more, and more preferably 6 or more, for example. The upper limit of the number of the electrodes is 10 or less, for example.
The number of the first insulating parts merely needs to be plural, namely 2 or more, and is not particularly limited thereto. The number may be determined based upon sizes of the holding apparatus 1 and the planar workpiece, electric field distribution, or the like. A larger number of the first insulating parts can prevent a concentration of electric currents to a greater degree, thus being able to achieve a uniform thickness of a plating film. The number of the first insulating parts is preferably 4 or more, and more preferably 6 or more, for example. The upper limit of the number of the first insulating parts is 10 or less, for example.
The number of the electrodes and the number of the first insulating parts may be the same but are preferably different. The number of the first insulating parts is more preferably larger than the number of the electrodes. A larger number of the first insulating parts than the number of the electrodes can prevent an electric current from flowing into the edge part of the planar workpiece, thus enabling reduction in an amount of plating that is deposited on the edge part of the planar workpiece.
The electrodes and the first insulating parts that are formed on the front member 13 are described in detail with
As shown in
The holding apparatus 1 of the present invention has the following characteristic. Provided that the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41 or the edge length of the opening part in the direction parallel to the width direction of the planar workpiece 41, whichever is smaller, is defined as 100, the edge part-covering length of the plurality of first insulating parts 31 or the plurality of electrodes 32 is 80 or more in the width direction of the planar workpiece 41 within the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41. That is, the edge part-covering length is within the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41. Setting the edge part-covering length of the plurality of first insulating parts 31 or the plurality of electrodes 32 to be 80 or more within the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41 renders an electric current less likely to flow into the edge part of the planar workpiece 41, thus enabling reduction in an amount of plating that is deposited on the edge part of the planar workpiece 41.
The edge part-covering length of the plurality of first insulating parts 31 or the plurality of electrodes 32 is preferably 90 or more, more preferably 95 or more, and most preferably 100 within the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41.
The edge part-covering length of the plurality of first insulating parts 31 or the plurality of electrodes 32 is determined based upon the edge length of the planar workpiece 41 in the width direction of the planar workpiece 41 or the edge length of the opening part in the direction parallel to the width direction of the planar workpiece 41, whichever is smaller, that is defined as 100. That is, the edge length 41a of the planar workpiece 41 in the width direction of the planar workpiece 41 and the edge length 12a of the opening part 12 in the direction parallel to the width direction of the planar workpiece 41 differ from one another when the planar workpiece 41 is disposed between the rear member 11 and the front member 13 of the holding apparatus 1 as shown in
Considering the above, in the present invention, the edge part-covering length of the plurality of first insulating parts 31 or the plurality of electrodes 32 is determined based upon the edge length 41a of the planar workpiece 41 in the width direction of the planar workpiece 41 or the edge length 12a of the opening part 12 in the direction parallel to the width direction of the planar workpiece 41, whichever is smaller, that is defined as 100. Hence, in
Each of the first insulating parts 31 and each of the electrodes 32 are preferably disposed alternately along an edge of the planar workpiece 41. This alternate disposition of each of the first insulating parts 31 and each of the electrodes 32 leads to uniform electric field distribution around each of the electrodes 32, thus being able to achieve a uniform thickness of a plating film. Each of the first insulating parts 31 and each of the electrodes 32 may be disposed in contact with one another or be disposed with space from one another.
More preferably, each of the first insulating parts 31 and each of the electrodes 32 are disposed alternately along the edge of the planar workpiece 41 and are in contact with one another. Disposing each of the first insulating parts 31 and each of the electrodes 32 in contact with one another eliminates space between each of the first insulating parts 31 and each of the electrodes 32, thus rendering an electric current less likely to flow into the edge part of the planar workpiece 41. As a result, an amount of plating that is deposited on the edge part of the planar workpiece 41 can be further reduced.
As shown in
Forming the curved part 32a at one end of each of the electrodes 32 imparts elasticity to the curved part 32a like a flat spring, and this elasticity can ensure contact between the curved part 32a and the planar workpiece 41 and thus transmission of an electric current. In addition, forming the curved part 32a across each of the electrodes 32 in the width direction of each of the electrodes 32 renders an electric current less likely to flow into the edge part of the planar workpiece 41, thus enabling reduction in an amount of plating that is deposited on the edge part of the planar workpiece 41. Examples of a shape of the curved part 32a include a curved shape and a bent shape.
Each of the electrodes 32 is preferably covered with an unillustrated insulating film except for a contact point of each of the electrodes 32 with the planar workpiece 41. Covering each of the electrodes 32 with the insulating film except for the contact point enables reduction in an amount of plating that is deposited on each of the electrodes 32. An example of the insulating film includes an insulating resin film but is not particularly limited thereto. Examples of the insulating resin film include a vinyl chloride film, a polyimide film, and a polyethylene terephthalate film.
As shown in
The projection 31a may have a pointed shape extending in a perpendicular direction to the surface of the rear member 11 as shown in
The projection 31a is preferably formed across each of the first insulating parts 31 in an entire width direction of each of the first insulating parts 31 (that is, entirely in the direction in which each of the first insulating parts 31 covers the edge part of the planar workpiece 41 in the width direction of the planar workpiece 41). Forming the projection 31a across each of the first insulating parts 31 in the width direction of each of the first insulating parts 31 renders an electric current less likely to flow into the edge part of the planar workpiece 41, thus enabling reduction in an amount of plating that is deposited on the edge part of the planar workpiece 41.
Each of the first insulating parts 31 may not contact the planar workpiece 41 but preferably contacts the edge part of the planar workpiece 41. Bringing each of the first insulating parts 31 into contact with the planar workpiece 41 renders an electric current less likely to flow into the edge part of the planar workpiece 41, thus enabling further reduction in an amount of plating that is deposited on the edge part of the planar workpiece 41. A material for each of the first insulating parts 31 may be any insulating material. Examples of the insulating material include vinyl chloride, polyimide, and polyethylene terephthalate. In addition, the material for each of the first insulating parts 31 preferably has elasticity.
As shown in
The second insulating part 33 preferably has a projection (for example, a weir) in a direction towards the surface of the rear member 11, and the projection is formed at a peripheral edge of the opening part 12. Forming the projection at an end part of the second insulating part 33 in the direction towards the surface of the rear member 11 renders an electric current far less likely to flow into the edge part of the planar workpiece 41, thus enabling further reduction in an amount of plating that is deposited on the edge part of the planar workpiece 41.
In particular, upon performing a Cu plating treatment as the electrolytic plating treatment, the holding apparatus with the second insulating part 33 that is formed on the front member 13 is preferably used, and more preferably, in the holding apparatus, the projection (for example, a weir) is formed at the edge part of the opening part 12 in the direction towards the surface of the rear member 11.
The front member 13 and the second insulating part 33 may be an integrated structure, but, as shown in
An embodiment of the present invention includes a method for applying an electrolytic plating treatment to a planar workpiece with the holding apparatus according to an embodiment of the present invention, and the electrolytic plating treatment is performed with each of the electrodes in contact with a plating solution. Performing the electrolytic plating treatment with each of the electrodes in contact with the plating solution facilitates transmission of an electric current and dissipation of heat, thus lowering an electric resistance. Such a lowered electric resistance consequently facilitates the plating treatment.
A description is given to the method for applying the electrolytic plating treatment to a planar workpiece with the holding apparatus according to an embodiment of the present invention. Firstly, the rear member 11 and the front member 13 are opened as shown in
<Others>
On an edge part of the planar workpiece 41, an insulating film may be formed. An example of the insulating film includes an insulating resin film, but the insulating film is not particularly limited thereto. Examples of the insulating resin film include a vinyl chloride film, a polyimide film, and a polyethylene terephthalate film. A width of the formed insulating film is preferably around 5 to 15 mm, for example, but is not particularly limited thereto. The insulating film is preferably formed on a part of the planar workpiece 41 including the edge thereof.
The open/close locks 14a and 14b may be any open/close locks that can prevent the rear member 11 and the front member 13 from opening during the electrolytic plating treatment without any particular limitation on their types. Examples of such open/close locks include ones having a projection and a recess that fit one another and ones that use magnetic force.
Beneath the holding apparatus 1, a guide 21 is preferably provided. This guide 21 can fix the holding apparatus 1 in the treatment tank for the electrolytic plating treatment by being inserted into a guide support provided in the treatment tank.
Number | Date | Country | Kind |
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2019-184835 | Oct 2019 | JP | national |
Number | Name | Date | Kind |
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20020000372 | Pedersen | Jan 2002 | A1 |
20050014368 | Yoshioka | Jan 2005 | A1 |
20060191786 | Yamamoto et al. | Aug 2006 | A1 |
20170372937 | Keigler | Dec 2017 | A1 |
20200149180 | Nishimoto et al. | May 2020 | A1 |
Number | Date | Country |
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206814873 | Dec 2017 | CN |
208455094 | Feb 2019 | CN |
109778289 | May 2019 | CN |
2002-161398 | Jun 2002 | JP |
2015-101764 | Jun 2015 | JP |
2019021607 | Jan 2019 | WO |
Entry |
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Search Report and Written Opinion dated Nov. 3, 2021 in Singapore Patent Application No. 10202009909S. |
Office Action dated Apr. 25, 2023 in corresponding Japanese Patent Application No. 2019-184835, with machine English translation. |
Office Action dated Sep. 29, 2023 in counterpart Chinese Application No. 202011048095.6, with English machine translation. |
Number | Date | Country | |
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20210102306 A1 | Apr 2021 | US |