Patent Application
20250092556
The present invention relates to a selective plating mask member and a selective plating method.
Patent document 1 discloses a plating masking jig that is installed on a circumference of a cylindrical drum that conveys a long material to be plated, and is used to supply plating solution only to a desired area of the material to be plated from an inside of the cylindrical drum, the masking jig including: a roll frame formed in a grid pattern, and a rubber sheet provided on a circumference of the roll frame with plated holes formed at positions corresponding to the desired area.
Patent document 2 discloses a plating device including a stationary drum, and a rotating tube which is disposed on an outer circumference of the stationary drum with a predetermined gap therebetween, and around which a strip or linear workpiece that is fed and moved in a longitudinal direction, is wrapped with a predetermined wrapping angle range.
Also disclosed is that an annular groove is formed on the outer circumference of the rotating tube, so that the workpiece is wrapped around the outer circumference in tight contact with a groove bottom, and an annular opening having a width smaller than a width of the groove bottom is formed at the annular groove bottom.
Also disclosed is that a mask is placed on the annular groove bottom to define a plating area, so that the workpiece can be wrapped on the mask.
Through intensive research by the inventor of the present invention, it is found that plating solution may leak from the gap between the workpiece referred to in Patent document 2 (plated material in Patent document 1) and the mask referred to in Patent document 2 (rubber sheet in Patent document 1).
Due to the leakage of the plating solution, plating oozes from the outer edge of a predetermined plating area (selective plating area). That is, due to the leakage of the plating solution, the plating solution protrudes from the selective plating area (the area where plating is scheduled), and plating is formed on an area that is not the selective plating area (that should not be plated). In this specification, “oozing of plating” refers to a situation that the plating that is thinner than the thickness of the selectively plated area is formed in areas other than the selectively plated area (which should not originally be plated).
Due to the oozing of plating, the plating solution corresponding to the oozing amount is wasted. When the type of plating is gold (Au) for example, the waste of the plating solution is a big economic loss.
An object of the present invention is to suppress oozing of plating when a material to be plated (workpiece) is selectively plated.
A first aspect of the present invention provides a selective plating mask member, including:
A second aspect of the present invention provides the selective plating mask member according to the first aspect, wherein at least the edge of the mask opening of the mask is made of rubber.
A third aspect of the present invention provides the selective plating mask member according to the first or second aspect, wherein in the jig opening arrangement region, a plurality of the jig openings are placed along the circumferential direction.
A fourth aspect of the present invention provides the selective plating mask member according to any one of the first to third aspects, wherein in the drum-shaped jig, the jig openings are placed in a predetermined pattern, and
A fifth aspect of the present invention provides the selective plating mask member according to any one of the first to fourth aspects, wherein the jig opening arrangement region is a recess provided in a strip shape around an entire circumference of the drum-shaped jig, that is, on an outer side surface of the drum-shaped jig.
A sixth aspect of the present invention provides the selective plating mask member according to any one of the first to fifth aspects, wherein a plurality of rows of combinations of the jig opening arrangement region and the mask are placed in a vertical direction of the drum-shaped jig.
A seventh aspect of the present invention provides the selective plating mask member according to any one of the first to sixth aspects, wherein in the drum-shaped jig, the jig opening arrangement region includes:
An eighth aspect of the present invention provides the selective plating mask member according to any one of the first to seventh aspects, wherein the mask opening coincides with the jig opening or at least selectively covers the jig opening.
A ninth aspect of the present invention provides a selective plating method, including:
An object of the present invention is to provide a selective plating mask member and a selective plating method that can suppress oozing of plating in areas other than the selective plating area, when selective plating is applied to a workpiece.
The present embodiment will be described below. “-” indicates a value greater than or equal to a given value and less than or equal to a given value.
The present embodiment provides a selective plating mask member including:
An overall mechanism of the selective plating mask member according to the present embodiment and the selective plating device into which the selective plating mask member is incorporated will be described.
In this specification, the directions are defined as follows.
An upward direction is the Z direction, and a downward direction is the −Z direction.
A radial direction from a circumference to a center is defined as the Y direction, and an opposite direction is defined as the-Y direction, which are perpendicular to the Z direction. The Y direction is also the direction from the outside to the inside of the drum-shaped jig 11, and is therefore also called an inward direction (when viewed from front). The −Y direction is also the direction from the inside to the outside of the drum-shaped jig 11, and is therefore also called an outward direction (when viewed from behind).
The directions perpendicular to the Z and Y directions are the X direction as a right direction and the −X direction as a left direction, respectively, when viewed in the Y direction (viewed from the front).
A top-bottom direction is the Z direction, and a horizontal plane is constituted of the X and Y directions.
The above directions are shown in each drawing of the present application.
As shown in
The workpiece 1 is redirected in its travel direction by an inlet side support roll 61, and is wound around the drum-shaped jig 11 in close contact with a mask 31 (described later) that is disposed on the outer surface side 16 of the drum-shaped jig 11. Thereafter, the workpiece 1 is wound around again by an outlet side support roll 62 and wound up.
The drum-shaped jig 11 is a cylindrical jig that conveys the workpiece 1 along its outer circumference while the workpiece 1 is in close contact with its side surface. A positioning pin 12 is provided on the side surface of the drum-shaped jig 11, and the position of the workpiece 1 on the drum-shaped jig 11 is fixed by fitting the positioning pin 12 into a guide hole formed in the workpiece 1. Then, when the position of the workpiece 1 is fixed, the jig opening 13 is formed on the side surface of the drum-shaped jig 11 so that an intended terminal position (i.e., a location to be plated, the selective plating area) and the jig opening 13 overlap on each other at the same position.
The workpiece 1 may be conveyed in a direction of the arrow shown in
The plating solution is pumped by a pump (not shown) into a plating solution jet cell 23 installed inside the drum-shaped jig 11, and is ejected from a plating solution ejection slit 24 which also serves as an anode, and is supplied toward the outside of the drum-shaped jig 11 through the jig opening 13 of the drum-shaped jig 11.
When the workpiece 1 is attached to the drum-shaped jig 11 and the selective plating mask member 50 which is composed of the mask 31 placed in the jig opening arrangement region 17 of the drum-shaped jig 11 described later, a plating solution is supplied to a surface portion of the workpiece 1 corresponding to the through hole composed of the jig opening 13 and the mask opening 32 of the mask 31.
The plating solution is continuously supplied to the plating solution jet cell 23 by a pump, and the plating solution accumulated in the plating solution jet cell 23 is ejected vigorously from the plating solution ejection slit 24.
In this manner, the plating solution is ejected onto the workpiece 1 while the workpiece 1 is being conveyed, and the workpiece 1 is selectively plated (selective plating). After plating, the workpiece 1 is washed with water and then dried with hot air or the like as a post-treatment.
In the selective plating mask member according to the present embodiment, the through hole composed of the jig opening 13 and the mask opening 32 (described later) serves as a plating solution supply port. The plating solution is supplied in a direction from the inside of the drum-shaped jig 11 to the outside of the drum-shaped jig 11. A portion (also called a spot) of the workpiece 1 exposed from the plating solution supply port is selectively plated (selective plating).
The plating solution supplied to the jig opening 13 (plating solution supply port) finally falls downward and is recovered in a plating solution tank (not shown) provided at a bottom of the drum-shaped jig 11. However, the recovered plating solution may be circulated using a plating solution recovery device (not shown) such as a pump, and may be reused for selective plating.
There is no limit in the material and shape of the workpiece 1, so long as it can be wrapped around the outer side surface 16 of the selective plating mask member and it enables the above-described selective plating. The material of the workpiece 1 is preferably copper, a copper alloy such as brass, or an iron alloy such as ordinary steel, special steel, or stainless steel, and the workpiece 1 is preferably in the form of a strip (strip or coil) or a plate. The plate thickness of the workpiece 1 can be appropriately selected depending on an application, and is preferably about 0.1 to 3.0 mm, and may be 0.8 mm or less.
The selective plating is applied to an electronic material such as a connector and terminal, but in the present embodiment, there is no limit in the type of metal used for selective plating. The metal used for selective plating of the electronic materials is usually expensive noble metal such as gold (Au) and silver (Ag), but prior to these selective plating, the strip-shaped workpiece 1 may be underplated with metal such as nickel and copper, over its entire or part of the surface. This underplating and selective plating can be performed in succession, by connecting a reel-to-reel type underplating facility with the selective plating device according to the present embodiment.
The selective plating mask member according to the present embodiment will be described in detail below.
The drum-shaped jig 11, which is a component of the selective plating mask member in the present embodiment, is not limited to a specific material or shape, for example, as long as it can be used for the same purpose as the drum-shaped jig 11 described in Patent document 2. Examples of materials include insulating polyvinyl chloride, PPS (polyphenylene sulfide) resin, and other engineering plastics. As one example of the configuration, the drum-shaped jig 11 has two annular (or disk-shaped) upper bottom portion 14 and lower bottom portion 15, and a cylindrical side surface formed by a cylindrical member sandwiched between the two bottom portions 14, 15.
The drum-shaped jig 11 constituting the selective plating mask member 50 according to the first embodiment shown in
When the jig opening arrangement region 17 is provided in a strip shape so as to be recessed relative to an entire circumference of the drum-shaped jig 11, this leads to an increase in the region in which the jig opening 13 can be secured, and is preferable. The first to third embodiments of the present invention show such a case for example. On the other hand, the jig opening arrangement region 17 may be recessed on only a part of the circumference, rather than the entire circumference. In other words, a part of the circumference may not be recessed, that is, a start point and an end point may be provided to the strip-like recess.
In the second embodiment, two rows of jig opening arrangement regions 17, which are recesses, are formed adjacent to each other in the vertical direction. Therefore, the two rows of jig opening arrangement regions 17 are one row of strip-like recessed regions (hole region 170 consisting of two rows of adjacent jig opening arrangement regions 17) wide in the vertical direction on the outer side surface 16 of the cylindrical member of the drum-shaped jig 11, and the outer side surface 16 of the drum-shaped jig 11 is not exposed between the two rows of jig opening arrangement regions 17. Therefore, due to a shape corresponding to the recess of the recessed region (hole region 170) in which the jig opening arrangement region 17 is provided, the mask 31 (embedding the hole region 170) placed in the hole region 170 (consisting of two rows of adjacent jig opening arrangement regions 17) appears to have one row of wide shape (strip shape) along the circumferential direction, as shown in
In the upper and lower jig opening arrangement regions 17, depending on the selective plating area of the workpiece 1, the jig openings 13 may or may not be placed vertically. When they are not placed vertically, the jig openings 13 in the upper row and the jig openings 13 in the lower row may be placed in a staggered manner alternately in the circumferential direction as shown in
As shown in
As shown in
It is preferable that the protrusions and grooves in the drum-shaped jig 11 be provided in one row of jig opening arrangement region 17, in addition to being formed over the circumference of the cylindrical member between the upper and lower jig opening arrangement regions 17.
As a specific example using one row of jig opening arrangement regions 17: in the jig opening arrangement region 17 which is a recess as shown in
As described above, in
In
As shown in
There is no limit in the number of jig openings 13. When a plurality of jig openings 13 are placed in one row along the circumferential direction, all jig openings 13 may or may not be placed in a fixed pattern. The “pattern” here refers to a pattern consisting of the jig opening 13 and other parts (each relatively convex region 41 and groove 42). The pattern may be formed by consecutively arranging pattern units in the circumferential direction.
As shown in
There is no limit in the number of relatively convex regions 41 in the pattern unit. For example, grooves may be provided in the relatively convex regions 41 extending in the circumferential direction, and grooves may be provided in three sets in the vertical direction×two sets in the circumferential direction, that is, as six relatively convex regions 41 in total.
The forms of the protrusions (relatively convex regions 41) and grooves 42 are not limited as long as they fit into the back surface of the mask 31. The “back surface of the mask 31” herein refers to the surface that comes into contact with the jig opening arrangement region 17 when placing (embedding) the mask 31 in the jig opening arrangement region 17 formed on the outer side surface 16 of the drum-shaped jig 11. The surface of the mask 31 opposite to the back surface of the mask 31, that is, the surface that comes into contact with the workpiece 1, is also referred to as a “front surface of the mask 31.”
As shown in
In the third embodiment shown in
As shown in
In the jig opening arrangement region 17 of the drum-shaped jig 11, for example, an opening (through-hole) other than the jig opening 13 (not shown) may be provided in a portion near the bottoms 14 and 15 of the drum-shaped jig 11. Protrusions (also referred to as legs of the mask 31) that are relatively long with respect to the thickness of the cylindrical member constituting the drum-shaped jig 11 are provided on the back surface of the mask 31, and these legs may be fitted into the openings. This configuration makes it difficult for the mask 31 to come off from the drum-shaped jig 11, resulting in a good fit between the two. Further, with this configuration, when fitting the two, the legs of the mask 31 are pulled from the inside of the drum-shaped jig 11, thereby making a fitting state of the two even better, and allowing an easy adjustment of the fitting state. There is no limit in the number of openings, and one mask unit (details will be described later) may have one or two or more openings.
There is no limit in the shape of the jig opening 13. The present embodiment shows a case in which the jig opening 13 is rectangular (square or rectangle) when viewed from the outside, but depending on a required shape of the selective plating area of an electronic member such as a terminal, the shape may be circular, oval, or other polygonal shape.
The size of the jig opening 13 is not limited as long as appropriate selective plating can be performed. An example of a specific size will be given in an example section below. It is preferable that the jig opening 13 corresponds to the shape and size of the selective plating area required for electronic components such as connectors and terminals.
The mask 31 according to the present embodiment embeds (covers) the jig opening arrangement region 17, which is a recess. The mask 31 according to the present embodiment has a mask opening 32 at a location corresponding to the jig opening 13. By fitting (placing) the mask 31 according to the present embodiment into the jig opening arrangement region 17, a through hole composed of the jig opening 13 and the mask opening 32 is provided. This through hole becomes a plating solution supply port.
In the present embodiment, the edge 33 of the mask opening 32 (more specifically, an entire edge 33, that is, the edge 33 surrounding the mask opening 32) is raised outward. By employing this configuration, leakage of the plating solution can be suppressed. The reason is as follows.
When the workpiece 1 is wrapped around the outer side surface 16 of the selective plating mask member 50 according to the present embodiment, the workpiece 1 is pressed against the surface of an uppermost mask 31 (and the side surface of the drum-shaped jig 11). Since the edge 33 of the mask opening 32 is raised, the workpiece 1 is pressed against the edge 33 of the mask opening 32, and since the edge 33 is deformed, it is possible to suppress the plating solution from entering between the mask 31 and the workpiece 1 at the outer circumference (edge 33) of the mask opening 32. Therefore, oozing of plating is also suppressed. Further, there is no need to waste plating solution, and economic loss is also suppressed.
With the above configuration, there is no limit in the material and aspect of the mask 31 according to the present embodiment. On the other hand, it is preferable that at least the edge 33 of the mask opening 32 of the mask 31 is made of rubber. When considering a processing effort, it is preferable that an entire mask 31 is made of rubber.
The “rubber” is not limited, but includes, for example, natural rubber, synthetic natural rubber, butadiene rubber, chloroprene rubber, silicone rubber (the present embodiment exemplifies these), acrylic rubber, urethane rubber, fluororubber, etc. Since the edge 33 of the mask opening 32 is made of rubber, when the workpiece 1 is pressed against the surface of the mask 31, the edge 33 deforms to be crushed according to the pressing force. As a result, the adhesion between the workpiece 1 and the edge 33 is improved, and leakage of the plating solution can be more effectively suppressed. It is preferable to use silicone rubber that has high chemical resistance to a chemical solution of the plating solution.
The dimension of the raised edge 33 of the mask opening 32 (protrusion distance and height from the base portion 34 other than the edge 33 when viewed from the outer side surface 16 to the inner side surface direction) may be appropriately set according to various conditions of plating. The conditions for this plating include the form of the jig opening arrangement region 17, the form of the jig opening 13, the planned thickness of the plating, the characteristics of the plating solution, the material of the entire mask 31 or the mask opening 32, etc.
A specific example of the height of the raised edge 33 of the mask opening 32 may be, for example, 0.1 mm or more and 0.5 mm or less, or 0.15 to 0.4 mm. The raised (protruded) height of the edge 33 of the mask opening 32 refers to the degree of protrusion (distance in the front view direction) of the mask opening 32 from the base portion 34 other than the edge 33 of the mask opening 32. With such a rubber edge 33 of the mask opening 32, when the raised height of the edge 33 of the mask opening 32 is 0.5 mm or less, the area of the through hole in front view is not reduced excessively if the edge 33 is crushed when the workpiece 1 is wrapped around the surface of the mask 31. So, a sufficient plating area can be secured. On the other hand, if the raised height is too small, there is a risk that the plating solution will infiltrate from between the mask 31 and the workpiece 1. Further, the width of the edge 33 of the opening 32 when viewed from the front is preferably 0.2 to 2.0 mm.
The distance between the mask opening 32 and the side edge portion 18 of the drum-shaped jig 11 according to the present embodiment is preferably 5.0 mm or more.
When viewed from the front, it is preferable that the mask 31 according to the present embodiment embeds (covers) the entire jig opening arrangement region 17, which is a recess, and the present embodiment shows such a case for example.
In the drum-shaped jig 11 of the third embodiment shown in
Further, conversely, the portion of the mask 31 other than the edge 33 of the mask opening 32 may be lower than the side edge portion 18. Even in that case, when the edge 33 of the mask opening 32 is raised compared to the side edge portion 18 and the side center part 19, leakage of the plating solution can be suppressed, and oozing of plating can also be suppressed.
The mask 31 according to the present embodiment is preferably constituted by arranging a plurality of parts each having n (n is a natural number) mask units (for example, the area P between the broken lines in
Further, as shown in
The parts may be molded separately for each mask unit, or may be formed by integrally molding a plurality of mask units (n pieces).
Further, for example, in the third embodiment shown in
In any case, when the mask 31 is made up of a plurality of parts, even if one part is damaged, only that part needs to be replaced, thus improving work efficiency.
The present embodiment shows a configuration in which when the mask 31 and the drum-shaped jig 11 are fitted together, the shape, size, and position of the mask opening 32 and the jig opening 13 are aligned. However, as long as the effects of the present invention are achieved, the mask opening 32 and the jig opening 13 may be misaligned when the mask 31 and the drum-shaped jig 11 are fitted together. Such a configuration includes a configuration in which the jig opening 13 and the mask opening 32 are misaligned, and a configuration in which the mask opening 32 is smaller than the jig opening 13.
In the case of the configuration in which the mask opening 32 is smaller than the jig opening 13, the lower side of the mask opening 32 may cover the lower contour of the jig opening 13.
There is no limit in the shape of the edge of the jig opening 13, and it is sufficient that the edge 33 of the mask opening 32 is raised when the mask 31 embeds the jig opening arrangement region 17. The shape of the edge of the jig opening 13 may be, for example, flat or recess, unlike the edge 33 of the mask opening 32.
Preferable examples of the size and positional relationship of the jig opening 13 of the drum-shaped jig 11 are as follows. As the following preferable example, the content described in Japanese Patent Application Laid-open No. 2018-165378 by the present applicant may be cited (particularly, the content related to
Similarly to the mask member 102 described in the publication, in the second embodiment shown in
The technical concept of the present invention is also reflected in the selective plating method in which the workpiece 1 is plated by supplying the plating solution to the jig opening 13 and the mask opening 32 in the workpiece 1 wrapped around a selective plating mask member. As a specific method for plating other than the selective plating mask member according to the present embodiment, a known method may be adopted.
The technical scope of the present invention is not limited to the above-described embodiments, but includes forms in which various modifications and improvements are made within the scope that can derive specific effects obtained by the constituent elements of the invention and their combinations.
The present invention will now be described in detail with reference to examples, but the present invention is not limited to the following examples.
In Example 1, the selective plating mask member was used, which had a configuration similar to that shown in
In Comparative example 1, the jig opening arrangement region 17, which is a strip shaped recess provided along the circumferential direction on the outer side 16 of the drum-shaped jig 11, is not provided and the mask 31 is not provided either. That is, the drum-shaped jig 11 was used as a selective plating jig, in which the selective plating mask member of the present invention is not used, the jig opening 13 is provided on the side surface, but a strip shaped recess including the jig opening 13 is not provided.
As a test material (material to be plated), a strip shaped workpiece 1 (width 50 mm×thickness 0.2 mm) was used, which was a copper alloy sheet material NB109-EH (Cu—Ni—Sn—P based copper alloy) manufactured by Dowa Metaltech Co., Ltd. and was coated with Ni plating having a thickness of 1.2 μm as an underplating.
The size of the opening (through hole) of the selective plating drum-shaped jig used in this comparative example, which is a rectangular through hole when viewed from the front, is 2.5 mm in the vertical direction×1.5 mm in the circumferential direction (the same applies to the following examples).
For selective plating, a hard Au plating solution with an Au concentration of 20 g/L, a Co concentration of 0.3 g/L, and a pH of 4.15 was used, and by performing electroplating for 4 seconds under conditions of a liquid temperature of 55° C. and a current density of 27 A/dm2, a spot-shaped selective Au plating M with a target thickness of 0.4 μm was formed on the surface of the strip shaped workpiece 1 facing the through hole.
The selective plating mask member has two adjacent rows of jig opening arrangement regions 17 each having a width of 14 mm in the vertical direction, and the corresponding mask 31 is constituted by combining 15 pieces of parts. When each jig opening arrangement region 17 is embedded with each part (is placed), no gaps are formed between the ends of each part.
Each jig opening 13 of the drum-shaped jig 11 and each mask opening 32 are rectangular, each measuring 2.5 mm in the vertical direction and 1.5 mm in the circumferential direction, forming a through hole having the same size composed of the jig opening 13 and the mask opening 32, and a raised edge 33 was formed to have a height of 0.2 mm and a width of 0.5 mm around the entire circumference of each mask opening 32. Further, selective spot-shaped Au plating was performed to a target thickness of 0.4 μm in the same manner as in Comparative example 1, except that a current density was set to 17 A/dm2.
As can be seen from
The Au spot plating (selective Au plating) formed on the surface of the workpiece 1 is dissolved in an Au stripping solution, and the Au in the stripping solution is quantitatively analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), to thereby evaluate an Au adhesion amount.
The above through hole is a rectangle of 2.5 mm in the vertical direction and 1.5 mm in the circumferential direction, and Au (spot) plating is formed in an area (plating area) corresponding to the through hole. Then, it was found that the Au adhesion amount deposited per Au spot plating was 0.0397 mg in Comparative example 1 and 0.0279 mg in Example 1.
That is, even though the Au spot plating was applied with the same area and target thickness, the Au adhesion amount in Example 1 was reduced by about 30% compared to the Au adhesion amount in Comparative example 1.
This is because oozing of Au plating occurred (a thin Au plating film is formed outside the plating area corresponding to the through hole) in Comparative example 1, and unnecessary Au plating was adhered to the workpiece.
The plating thicknesses in Comparative example 1 and Example 1 were both approximately 0.4 μm, which were equivalent each other. In Comparative example 1, there was a large loss in the Au adhesion amount due to oozing of selective Au plating, so it was necessary to increase the current density in order to achieve the same plating thickness for the same selective Au plating time.
The same procedure was followed as in Comparative example 1 (including the Au plating time) except that the current density was set to 17 A/dm2, and spot-like selective Au plating was performed using the drum-shaped jig 11 (without the mask 31 attached).
As a result, similarly to the Comparative example 1, oozing of Au plating was observed in an area other than a designated spot area (selectively plated area). Further, due to the same current density and Au plating time, although the Au adhesion amount in Comparative example 2 was equivalent to that in Example 1, the thickness of the Au plating at the Au spot plating portion was only about 0.25 μm due to the oozing.
As shown in
The selective plating mask member used herein was the mask member in which each jig opening 13 of the drum-shaped jig 11 and each mask opening 32 are rectangular, each measuring 2.5 mm in the vertical direction and 1.5 mm in the circumferential direction, forming the through hole having the same size composed of the jig opening 13 and the mask opening 32, but the edge 33 of the mask opening 32 is not raised.
A spot-like selective Au plating was formed on the surface of the strip shaped workpiece 1 in the portion facing the through hole, by performing electroplating in the same manner as in Comparative example 1, except that a hard Au plating solution with an Au concentration of 21 g/L and a Co concentration of 0.2 g/L was used for selective plating, and the liquid temperature was set to 55° C., pH was set to 4.15, the current density was set to 29 A/dm2, the target plating thickness was set to 1.15 μm, and the Au plating time was set to 15 seconds.
In Comparative example 3, as in Comparative example 1, a large amount of oozing occurred in the plating of the workpiece 1.
A spot-like selective Au plating was formed using the drum-shaped jig of Example 1 in the same manner as in Example 1, except that the current density was set to 30 A/dm2, the plating time was set to 11 seconds, and the target plating thickness was set to 1.3 μm.
A spot-like selective Au plating was formed using the drum-shaped jig of Comparative example 1 in the same manner as in Comparative example 1, except that the current density was set to 30 A/dm2 and the plating time was set to 11 seconds.
As a result, oozing of plating was less in Example 2 compared to Comparative example 4.
Further, due to the same current density and Au plating time, the Au adhesion amount in Comparative example 4 was equivalent to that in Example 2, but due to the oozing, the Au plating thickness of the Au spot-plated portion in Comparative example 4 was about 1.0 μm, whereas that in Example 2 was about 1.3 μm.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-024475 | Feb 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/021604 | 5/26/2022 | WO |
