JP2012201944A - Plating apparatus for metal-coated resin substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating apparatus which can make the plating thickness distribution nearly uniform without any rise in a plating voltage in producing a metal-coated resin substrate by a vertical suspension plating process in which the surface to be plated is a substantially vertical.SOLUTION: In the plating apparatus for the metal-coated resin substrate, the resin substrate surfaced with a base metal layer as the surface to be plated is disposed in such a manner that the surface to be plated is substantially vertical, and a shielding plate is disposed between an electrode arranged on the side opposite to the surface to be plated and the surface to be plated. The shielding plate is a plate-like member and has a shape tapering in width in such a manner that the upper and lower edges of the member incline at a constant inclination angle with respect to the upper and lower edges of the resin substrate toward the direction from their front sides to their rear sides.

Description

  The present invention relates to a plating apparatus for a metal-coated resin substrate, particularly a metal-coated polyimide substrate, and more particularly to a plating apparatus for a metal-coated resin substrate for further uniforming the plating thickness in metal coating by a vertical suspension plating apparatus. .

In recent years, electronic components used with the miniaturization of electronic devices have been required to be miniaturized, and as a wiring material used for manufacturing such electronic components, for example, as shown in Patent Document 1, polyimide film or the like There is known a two-layer plating substrate in which a thin metal layer is formed on an organic resin film, and copper is electroplated on the metal layer with a thickness of several μm to several tens of μm. A two-layer plated substrate manufactured by electroplating has a fine wiring pattern formed on the surface by a photolithography technique, and is used as a wiring material for connecting a liquid crystal panel and a driver IC in a mobile phone or a television. In this two-layer plated substrate, the finer the wiring pattern formed on the substrate surface, the greater the amount of information transmitted per unit area. Therefore, the wiring pattern on the substrate surface can be used to reduce the size, speed and cost of liquid crystal equipment. However, ultra-fine wiring patterns with a wiring pitch of 20 μm or less have recently been formed.
With such a narrowing of the wiring pitch, a two-layer plating substrate with a small variation in plating thickness has been demanded. This is because if the variation in the plating thickness is large, fine wiring cannot be formed, causing defects such as disconnection or short circuit. For this reason, recently, it is required that the variation in plating thickness is 10% or less.

  In general, as a method for uniforming the plating thickness distribution, a method is used in which a shielding plate is installed between the electrode (anode: anode) and the material to be plated to make the current distribution in the plating tank uniform. . FIG. 6 shows a conventional method used for manufacturing a two-layer plating substrate in which a thin metal layer is formed on an organic resin film such as a polyimide film and copper is electroplated on the metal layer with a thickness of several μm to several tens of μm. A plating apparatus, that is, a vertical suspension plating apparatus is illustrated (see Patent Document 1). This vertical suspension plating apparatus employs an electroplating method in which a substrate to be plated (an organic resin film such as a polyimide film) provided with a base metal layer on the surface is a substantially vertical surface. An electrode (anode: anode) 2 and a plating solution jet nozzle 3 are disposed in the plating tank 1, and a resin substrate (work: material to be plated) 4 is opposed to the side opposite to the electrode 2 and the surface to be plated is present. A rectangular plate-like member is suspended between the electrode 2 and the surface 4a to be plated, which is suspended by the work holding plate 5 so as to be a substantially vertical surface and is disposed on the side of the resin substrate 4 facing the surface 4a to be plated. The shielding plate 6 made of is arranged. In the figure, 7 is a clamper that holds the resin substrate 4 and serves as a cathode (cathode), and 8 is a transport rail.

JP 2010-31316 A

However, the conventional metal-coated resin substrate plating apparatus having the above-described configuration has the following problems.
That is, in the conventional metal-coated resin substrate plating apparatus having the above-described configuration, as shown in FIG. 7, the shielding plate 6 includes the upper and lower sides of the resin substrate 4 that is the material to be plated, and the upper and lower sides of the shielding plate 6. Since a rectangular plate-like member is used, the current concentrates on the resin substrate 4 corresponding to the end of the shielding plate 6 and the plating thickness of the surface to be plated 4a is locally increased. Arise. Therefore, conventionally, it is necessary to adjust the plating thickness of the entire resin substrate 4 to be uniform while installing a new shielding plate in such a current concentration portion. In addition to complicating the installation position adjustment, there is a problem in that, when the position adjustment of the shielding plate is not performed with high accuracy, the plating voltage increases and the product manufacturing cost increases.

  The present invention has been made to solve the above-described problems of the prior art, and can easily and quickly adjust the position of the shielding plate, and can increase the plating thickness distribution without increasing the plating voltage. It is an object of the present invention to provide a metal-coated resin substrate plating apparatus that can be made more uniform.

  In the plating apparatus for a metal-coated resin substrate according to the present invention, a resin substrate having a base metal layer on the surface as a surface to be plated is disposed so that the surface to be plated is a substantially vertical surface, and the surface to be plated is provided. In the metal-coated resin substrate plating apparatus in which a shielding plate is disposed between the electrode disposed on the opposite side and the surface to be plated, the upper side and the lower side of the plate-like member are rearward from the front end side as the shielding plate. A plate-like member having a shape that is tapered toward the end side in a tapered shape with a certain inclination angle with respect to the upper side and the lower side of the resin substrate is used.

  Moreover, the plating apparatus of this invention makes it a preferable aspect that the inclination angles of the upper side and the lower side of the shielding plate are 5 to 20 degrees with respect to the upper side and the lower side of the resin substrate.

  In the plating apparatus for metal-coated resin substrates according to the present invention, the shielding plate used to make the plating thickness distribution of the resin substrate uniform is arranged such that the upper side and the lower side of the plate-shaped member are directed from the front end side to the rear end side. Consists of a plate-like member with a taper shape with a fixed inclination angle with respect to the upper and lower sides of the resin substrate, eliminating current concentration at the edge of the shielding plate and increasing the voltage with a small number of shielding plates It is possible to make the plating thickness distribution more uniform without accompanying. Therefore, according to the apparatus of the present invention, it is possible to manufacture a high-quality two-layer plating substrate with small variations in plating thickness at low cost, and it is possible to sufficiently cope with narrowing of the wiring pitch. There is an effect.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which expands and shows the principal part of one Example apparatus of the metal-coated resin board | substrate plating apparatus which concerns on this invention. It is a front view which shows the shielding board single-piece | unit in an apparatus same as the above. It is a figure which shows the plating thickness distribution in Example 1 of this invention corresponding to arrangement | positioning of a shielding board. It is a figure which shows the plating thickness distribution in the prior art example 1 of this invention corresponding to arrangement | positioning of a shielding board. It is a figure which similarly shows the plating thickness distribution in the prior art example 2 of this invention corresponding to arrangement | positioning of a shielding board. It is a schematic diagram which shows an example of the conventional metal coating resin board | substrate plating apparatus, (a) is a top view of a plating apparatus, (b) is an ea line sectional drawing of (a). It is a schematic diagram which expands and shows the principal part of a plating apparatus same as the above.

  The metal-coated resin substrate plating apparatus shown as an embodiment of the present invention in FIGS. 1 to 2 is a resin substrate having a base metal layer as a surface to be plated on the surface, similar to the vertical suspension plating apparatus shown in FIG. (Organic resin film such as polyimide film) adopts an electroplating method in which the surface to be plated becomes a substantially vertical surface, and an electrode (anode: anode) 2 and a plating solution jet nozzle 3 are disposed in the plating tank 1. A resin substrate (workpiece: material to be plated) 4 is suspended by a workpiece holding plate 5 so that the surface to be plated is a substantially vertical surface so as to face the opposite side of the electrode 2, and the resin substrate 4 is plated. A shielding plate 6 is disposed between the electrode 2 disposed on the side facing the surface 4a and the surface to be plated 4a.

  The apparatus of the present invention is an improvement of the shape of the shielding plate used in the method for uniformizing the current distribution in the plating tank 1 in the plating apparatus having the above-described configuration. As shown in FIGS. The plate 16 replaces the conventional shielding plate 6 using a rectangular plate-like member in which the upper and lower sides of the resin substrate 4 that is the material to be plated and the upper and lower sides of the shielding plate are parallel to each other. In addition, a plate-like member having a shape in which the lower side is tapered toward the rear end side from the front end side to the upper side and the lower side of the resin substrate 4 at a fixed inclination angle is employed.

Here, the shielding plate for equalizing the current distribution in the plating tank 1 is fixed with respect to the upper side and the lower side of the resin substrate 4 with the upper side and the lower side of the plate-like member directed from the front side to the rear side. The reason why the plate-like member is formed to have a taper shape with the inclination angle is as follows.
The current blocked by the shielding plate flows along the shielding plate and then flows from the end of the shielding plate toward the resin substrate 4. Therefore, when the shielding plate does not have a taper shape, the current always concentrates on the same line in the width direction of the resin substrate 4, and the plating thickness of the resin substrate corresponding to the upper side and the lower side of the shielding plate is increased. In the conventional shielding plate, in order to eliminate the increase in plating thickness at the end of the shielding plate, a shielding plate is added to the thickened portion of the plating thickness, and many shielding plates are combined in a complex manner to reduce the plating thickness. It was necessary to make it uniform. On the other hand, since the shielding plate of the present invention has a tapered shape, the current concentration portion is shifted little by little in the width direction of the resin substrate 4, and the local increase in plating thickness can be eliminated.

Further, the inclination angle θ of the upper side and the lower side of the shielding plate 16 is defined as 5 to 20 degrees with respect to the upper side and the lower side of the resin substrate 4 when the inclination angle θ is less than 5 degrees. This is because the deviation of the current concentrating portion is small so that a thick plating line is formed along the upper and lower sides of the shielding plate.
On the other hand, when the angle exceeds 20 degrees, the shielding margin other than the portion where the plating thickness is desired to be reduced due to shielding increases, and as a result, the plating thickness distribution deteriorates.

Using the metal-coated resin substrate plating apparatus shown in FIG. 6, as the shielding plate 16 of the present invention, the tip side width W = 80 mm, the length L = 500 mm × 10 pieces, the upper side and the lower side inclination angles θ shown in FIG. A plate-like member having a thickness of 3 mm and 15 degrees was used. In this embodiment, the shielding plates 16 are installed on the same vertical plane with an interval of two sheets above and below.
The resin substrate (work) 4 is obtained by providing a nickel layer having a thickness of 20 nm on the surface of a polyimide film (Kapton NF: manufactured by Toray DuPont) having a thickness of 38 microns by a sputtering method, and providing a copper layer having a thickness of 100 nm thereon. .
The plating solution used was copper sulfate 120 g / l, sulfuric acid 210 g / l, chlorine 50 mg / l, HL (Atotech Kaparaside HL (leveler component)) 20 ml / l, GS (Atotech Kaparaside GS (Prytner). Component)) is added at a rate of 5 ml / l. The temperature of the plating solution is 24 ° C., the workpiece conveyance speed is 0.4 m / min, the amount of liquid supplied to the plating tank is 28 l / min per plating solution jet nozzle, and the current density and energization time required for plating are as follows: The inside of the plating tank 1 is divided into four sections, 0.5 A / dm ² and 1 minute in the first section, 1.0 A / dm ² and 1 minute in the second section, and 2.0 A / dm ² in the third section. 1 minute, and in the fourth division, 3.0 A / dm ² and 12 minutes.
The plating thickness distribution in this example is shown in FIG.

  From the plating thickness distribution shown in FIG. 3, it can be seen that according to the shielding plate of the present invention, the plating thickness distribution is substantially uniformed by eliminating the current concentration at the end of the shielding plate. Moreover, the variation of the plating thickness was as low as about 8%, and the target of 10% or less could be achieved. Furthermore, in this example, since the shielding plate was composed of two sheets, almost no increase in plating voltage was confirmed.

  Plating was formed on the resin substrate (workpiece) 4 in the same manner as in Example 1 except that the inclination angle θ of the upper side and the lower side was set to 5 degrees. The variation in plating thickness after plating formation was as low as 10%, and the target of 10% or less could be achieved.

  The resin substrate (workpiece) 4 was plated in the same manner as in Example 1 except that the inclination angle θ of the upper side and the lower side was set to 20 °. The variation in plating thickness after plating formation was as low as 10%, and the target of 10% or less could be achieved.

(Comparative Example 1)
Plating was formed on the resin substrate (workpiece) 4 in the same manner as in Example 1 except that the inclination angle θ of the upper side and the lower side was set to 3 degrees. The variation in plating thickness after plating formation was 13%, and the target of 10% or less could not be reached.

(Comparative Example 2)
Plating was formed on the resin substrate (workpiece) 4 in the same manner as in Example 1 except that the inclination angle θ of the upper side and the lower side was set to 25 °. The variation in plating thickness after plating formation was 12%, and the target of 10% or less could not be reached.

(Conventional example 1)
Plating treatment was performed under the same conditions as in Example 1 except that two shielding plates made of rectangular plate members having a width W = 50 to 100 mm, a length L = 500 mm × 10 and a thickness of 3 mm were used as the shielding plate. As a result, as shown in FIG. 4, the plating thickness distribution is such that the plating thickness of the portion hidden by the shielding plate is reduced and the current concentrates on the edge of the shielding plate, so that a portion with a thick plating thickness is generated locally, The variation of the plating thickness was about 15%, exceeding the target of 10%.

(Conventional example 2)
Plating treatment was performed under the same conditions as in Example 1 except that six shielding plates made of rectangular plate members having a width W = 50 to 100 mm, a length L = 500 mm × 10 and a thickness of 3 mm were used as the shielding plates. Went. The result is shown in FIG. In Conventional Example 2, a new shielding plate was sequentially installed at locations where the plating thickness locally increased due to the two shielding plates in Conventional Example 1, and the plating thickness distribution was uniformized. As a result, also in this conventional example 2, as shown in FIG. 5, the plating thickness varied by about 12%, and did not reach the target of 10% or less. Furthermore, since many shielding plates were installed, the voltage rose about 1.5V.

  In the plating apparatus for metal-coated resin substrates according to the present invention, the shielding plate used to make the plating thickness distribution of the resin substrate uniform is arranged such that the upper side and the lower side of the plate-shaped member are directed from the front end side to the rear end side. Consists of a plate-like member with a taper shape with a fixed inclination angle with respect to the upper and lower sides of the resin substrate, eliminating current concentration at the edge of the shielding plate and increasing the voltage with a small number of shielding plates As a result, the plating thickness distribution can be made more uniform without the need for high-quality two-layer plating substrates with small plating thickness variations, which can be produced at low cost, and the wiring pitch can be narrowed sufficiently. In particular, it greatly contributes to improving the quality and cost of wiring materials in the electronics field.

1 Plating tank 2 Electrode (Anode: Anode)
3 Plating solution jet nozzle 4 Resin substrate 4a Surface to be plated 5 Work holding plate 6, 16 Shield plate 7 Clamper 8 Transport rail

Claims (2)

  A resin substrate having a base metal layer on the surface as a surface to be plated is disposed so that the surface to be plated is a substantially vertical surface, and an electrode installed on the side facing the surface to be plated and the surface to be plated In the plating apparatus for a metal-coated resin substrate in which a shielding plate is disposed between the upper and lower sides of the resin substrate with the upper and lower sides of the plate-shaped member from the front end side toward the rear end side as the shielding plate. A metal-coated resin substrate plating apparatus characterized by using a plate-like member having a shape that is reduced in a taper shape at a constant inclination angle.   2. The metal-coated resin substrate plating apparatus according to claim 1, wherein an inclination angle of an upper side and a lower side of the shielding plate is 5 to 20 degrees with respect to an upper side and a lower side of the resin substrate.