JP2017082339A - Stainless substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stainless substrate having a polymer compound layer and a thin and flawless gold plating layer pattern at a desired portion.SOLUTION: A stainless substrate includes main planes opposing to each other, and a processing portion formed with a face different from the main planes. The stainless substrate further includes a gold plating pattern located at least at the processing portion and a polymer compound layer located at a desired portion excluding the processing portion, interposing a gold plating layer thinner than the gold plating pattern.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stainless steel substrate having a polymer compound layer and a gold plating pattern partially at a desired site.

  Conventionally, stainless steel has been used in various products such as connectors, fuel cells, hard disk suspensions, device cases, etc. as a form of a substrate or the like. And, in order to partially increase the corrosion resistance of the stainless steel substrate or to conduct external connection, for example, after roughening the surface of the stainless steel substrate, a conductive material such as copper, nickel, silver, or gold may be deposited. (Patent Document 1).

Further, by providing a desired polymer compound layer on a stainless steel substrate, a surface buffer function, a vibration damping function, a surface plating area limiting function, and the like are imparted. For example, in a hard disk suspension, a polymer compound layer in which a restraint body made of a resin film and a viscoelastic body made of an adhesive are laminated on a load beam made of stainless steel is bonded to provide a vibration damping function. (Patent Documents 2 to 6). Also, a hard disk suspension material in which a conductive metal layer having a large surface roughness is formed on a stainless steel substrate, and an insulating layer such as polyimide resin and a metal foil layer for forming an electric circuit are laminated on the conductive metal layer. Is known (Patent Document 7). Furthermore, a respiratory filter device that is attached to a top cover of a magnetic disk device case and includes a damping member for suppressing vibrations acting on the case has been developed (Patent Document 8).
On the other hand, since the adhesiveness between the passive film on the surface of the stainless steel substrate and the resin is low, the surface of the stainless steel substrate is subjected to laser processing or a primer layer containing an inorganic silicon compound can be used to increase the adhesiveness to the resin. Improvements have been made (Patent Documents 9 and 10).

JP 2003-247097 A JP-A-10-162532 Japanese Patent Laid-Open No. 11-185415 Japanese Patent Laid-Open No. 11-66780 JP 2001-82537 A JP 2010-20827 A JP 2007-220785 A JP 2000-222873 A JP 2010-167475 A JP 2010-228257 A

However, for example, a polymer compound layer in which a restraint body and a viscoelastic body are laminated and an adhesive is used for the viscoelastic body is attached to a stainless steel substrate, and then adjacent to the polymer compound layer. In addition, when a gold plating pattern is partially formed, the viscoelastic body constituting the polymer compound layer is dissolved during the plating process, which is a wet process, and the adhesion to the stainless steel substrate may be reduced. Further, even at the interface between the restraint body and the viscoelastic body, the dissolution of the viscoelastic body may progress during the wet process, and the two may be peeled off.
On the other hand, the formation of the polymer compound layer on the conductive metal layer previously formed on the stainless steel substrate has a higher adhesion than the case where the polymer compound layer is formed directly on the stainless steel substrate surface where the passive film exists. It will be expensive. However, in order to form a gold plating pattern partially so as to be adjacent to the polymer compound layer, a plating process that is a wet process is required, and when the polymer compound layer includes a viscoelastic body, Similarly, the viscoelastic body may be dissolved. Even in a polymer compound layer that does not include a viscoelastic body, the adhesion to the conductive metal layer may be reduced by an alkaline stripping solution in a plating process that is a wet process.

  In addition, in the formation of the conductive metal layer on the stainless steel substrate as described above, it is necessary to remove the passive film present on the surface of the stainless steel substrate, but the removal treatment of the passive film on the stainless steel substrate is insufficient. Then, the adhesion of the conductive metal layer becomes non-uniform or poor adhesion occurs. On the contrary, when the passive film removal process becomes excessive, there is a problem that the surface corrosion of the stainless steel substrate occurs. For this reason, the plating process that can form a conductive metal layer while removing the passive film present on the surface of the stainless steel substrate is considered to be the most effective. There are significant restrictions on the formation of the conductive metal layer. On the other hand, if an intermediate layer is formed using a plating type that provides good adhesion, and a desired conductive metal layer is formed on this intermediate layer, the number of processes increases, which affects production efficiency. Will be affected.

In addition, as described in Patent Document 7, in order to form a conductive metal film having a large surface roughness, it is necessary to thicken the plating layer. However, if the plating layer is thickened, the plating treatment time becomes long, On the other hand, there is a problem that a pitting corrosion phenomenon that selectively dissolves an iron component occurs, while a local removal action of the passive film on the stainless steel substrate occurs and adhesion of the plating layer is improved.
This invention is made | formed in view of the above situations, and it aims at providing the stainless steel substrate which has a polymer compound layer and the pattern of the thin gold plating layer without a defect in a desired site | part.

  In order to solve such a problem, the present invention comprises an opposing main plane and a processing portion constituted by a surface different from the main plane, and at least a gold plating pattern positioned in the processing portion, And a polymer compound layer located at a desired site excluding the processed site via a gold plating layer thinner than the gold plating pattern.

  As another aspect of the present invention, the gold plating pattern is configured to be located only at the processing site.

  As another aspect of the present invention, the gold plating pattern has a thickness that is less than 1/10 of the thickness of the polymer compound layer.

  According to the present invention, the first gold plating layer is formed using the hydrochloric acid plating solution on the entire surface of the pretreated stainless steel substrate or on a desired site, so that the stainless steel substrate and the first gold plating layer are in close contact with each other. The property is good. In addition, since the polymer compound layer is provided by melt-compression bonding of the polymer compound on the first gold plating layer, better adhesion can be obtained compared to the case where the polymer compound layer is directly formed on the stainless steel substrate. And the adhesive fall in the wet process which is subsequent 2nd gold plating layer formation is suppressed. Further, the second gold plating layer is formed in a desired pattern only at a desired portion of the first gold plating layer, and then the first gold plating layer is peeled and removed using an alkaline stripping solution. Erosion is prevented. Moreover, since there is no difference in ionization tendency between the first gold plating layer and the second gold plating layer, the second gold plating layer does not erode and the thickness of the second gold plating layer can be reduced. it can. Thereby, a thin film pattern of 1 μm or less can be formed on the stainless steel substrate. Moreover, since the pattern of the formed gold plating layer is a two-layer structure, both layers are gold plating layers, so that a stable coating without causing a battery reaction between the layers is obtained. Furthermore, if the stainless steel substrate has an unnecessary part of the gold plating pattern, this part can be exposed, so even if the stainless steel substrate has been processed in advance, this processed part can be utilized. There will be no hindrance. Moreover, when forming a gold plating layer only in a desired site | part using a resist pattern, gold usage-amount can be restrained and a gold plating pattern can be formed efficiently.

It is process drawing for demonstrating one Embodiment of the formation method of the high molecular compound layer and partial gold plating pattern to the stainless steel board | substrate of this invention. It is a fragmentary sectional view showing other examples of a stainless steel substrate which has a processing part. It is process drawing for demonstrating other embodiment of the formation method of the high molecular compound layer and partial gold plating pattern to the stainless steel substrate of this invention. It is process drawing for demonstrating an example of the formation method of the partial gold plating pattern of this invention. It is a figure for demonstrating the other example of the formation method of a partial gold plating pattern. It is process drawing for demonstrating other embodiment of the formation method of the high molecular compound layer and partial gold plating pattern to the stainless steel substrate of this invention.

Hereinafter, embodiments of the present invention will be described.
<First Embodiment>
FIG. 1 is a process diagram for explaining an embodiment of a method for forming a polymer compound layer and a partial gold plating pattern on a stainless steel substrate.
In the present embodiment, after the pretreatment is performed on the stainless steel substrate 1 in the first plating process, the first gold plating layer 11 is directly formed on the entire surface of the stainless steel substrate 1 using a hydrochloric acid plating solution (FIG. 1 ( A)).
There is no restriction | limiting in particular in the stainless steel of the stainless steel board | substrate 1, For example, you may consist of an austenitic series and a ferritic stainless steel. The stainless steel substrate 1 in the illustrated example has opposing main planes 1a and 1b, and has a through-hole 2 formed of a wall surface 2a different from the main planes 1a and 1b as a processing part. The 1st gold plating layer 11 is formed in 1b and the wall surface 2a which comprises the through-hole 2 which is a process site | part. The number, position, size, and shape of the through-hole 2 as a processing part are not limited.
In addition, in this invention, a main plane is a pair of plane which opposes in the thickness direction of a stainless steel substrate in the state before giving processing, such as an etching process and a press process.

The pretreatment for the stainless steel substrate 1 is for the purpose of activating by removing the surface degreasing and the passive film, for example, from a treatment method such as alkali dipping treatment, alkaline electrolytic treatment, acid electrolytic treatment, acid dipping treatment, etc. It can be selected as appropriate. Note that the transition time from the pretreatment to the formation of the first gold plating layer 11 is set to a range in which the passive film is not re-formed on the stainless steel substrate 1.
The first gold plating layer 11 is formed using a hydrochloric acid plating solution. It is preferable to use a hydrochloric acid plating solution to be used in consideration of preventing erosion of the stainless steel substrate 1 and shortening the plating time. For example, a hydrochloric acid plating solution prepared so that the degree of occurrence of micropitting on the surface of the target stainless steel substrate 1 is 2 or less per unit area (mm ² ) can be used. Here, the micropitting is measured by immersing the stainless steel substrate in a hydrochloric acid plating solution for 10 seconds, washing with water and drying, and then observing with a scanning electron microscope. By using such a hydrochloric acid plating solution, moderate dissolution occurs on the surface of the stainless steel substrate 1 as a simultaneous action during gold plating, and thereby the adhesion between the first gold plating layer 11 and the stainless steel substrate 1 is good. It will be something.

  The upper limit of the thickness of the first gold plating layer 11 to be formed can be 0.15 μm, preferably less than 0.10 μm. When the thickness of the first gold plating layer 11 is 0.10 μm or more, the peeling efficiency of the first gold plating layer 11 in the peeling process is reduced, the time required for peeling is increased, or a high concentration peeling solution is required. Is not preferable. Moreover, it is preferable to set the minimum of the thickness of the 1st gold plating layer 11 to be formed according to the plating solution used at a 2nd plating process. That is, when a cyan plating solution is used in the second plating step, the lower limit of the thickness of the first gold plating layer 11 is set to 0.010 μm in consideration that uniform film thickness control is possible. When using a hydrochloric acid plating solution in the second plating step, the lower limit of the thickness of the first gold plating layer 11 is to prevent corrosion of the stainless steel substrate by the hydrochloric acid plating solution in the second plating step. And 0.015 μm.

Here, the thicknesses of the first gold plating layer and the second gold plating layer to be described later are measured as follows. That is, after each plating layer is formed, measurement is performed using a fluorescent X-ray film thickness measuring device manufactured by Seiko Instruments Inc. In advance, prepare a thin standard foil and a thick standard foil that include the target film thickness to be measured, and use at least these two standard foils to create a calibration curve between the X-ray output and the film thickness. Create in advance. In addition, after processing the cross-section with FIB (focused ion beam), the cross-section is observed with SEM (scanning electron microscope), and the gold particles appearing in the cross-section are measured based on the scale corresponding to the magnification to be photographed. Check the thickness of each layer of different size.
In addition, you may perform a neutralization process for the purpose of activation of the 1st gold plating layer 11 formed at the 1st plating process. By performing such activation, the adhesion between the polymer compound layer and the second gold plating layer in the subsequent process is further improved.

Next, in the polymer compound layer formation step, the polymer compound layer 15 is provided by melt-bonding the polymer compound at a desired site on the first gold plating layer 11 (FIG. 1B). Examples of the polymer compound used include polyimide, polyethylene terephthalate (PET), polypropylene, polyamide, and acrylic resin. In melt compression bonding, a polymer compound film having a desired shape is placed on the first gold plating layer 11, and the temperature at which the polymer compound can be bonded, for example, 10 to 50 ° C. higher than the melting point of the polymer compound to be used. The polymer compound layer 15 can be formed by pressure-bonding the polymer compound film to the first gold plating layer while heating the polymer compound film at a relatively high temperature, and then solidifying. In addition, a polymer compound is supplied in a molten state on the first gold plating layer 11 to form a polymer compound film having a desired shape, and after cooling to a pressable state, the polymer compound film is first gold-plated. The polymer compound layer 15 can be formed by pressure bonding to the plating layer and then solidifying. Examples of the pressure bonding means include a roll laminator configured with two silicon rollers as a pair, a vacuum press type laminator, and a heater for locally pressing only the polymer compound layer. A plate-type heater or the like can be used, and the pressure bonding conditions can be set, for example, in a range of 1 × 10 ^{5 to} 5 × 10 ⁵ N / m ² . Further, ultrasonic vibration bonding or the like may be used at the time of melt-bonding.
The formation position, shape, and dimensions of the polymer compound layer 15 on the first gold plating layer 11 are not particularly limited, and can be set as appropriate depending on functions required for the polymer compound layer 15. For example, the thickness of the polymer compound layer 15 can be appropriately set in the range of 20 to 200 μm.

  Next, in the second plating step, mask plating (FIG. 1C) using the mask 16 having the opening 17 and the mask 16 'having the opening 17 ′ (FIG. 1 (C)) causes the polymer compound layer 15 not to exist. The 2nd gold plating layer 12 is formed in the desired part of 1 gold plating layer 11 (Drawing 1 (D)). In the illustrated example, the first gold plating layer 11 located on the first gold plating layer 11 that covers the wall surface of the through hole 2 that is the processing site of the stainless steel substrate 1 and between the processing site and the polymer compound layer 15. A second gold plating layer 12 is formed thereon.

The mask 16 ′ used for mask plating in the second plating step has an area S 1 of the opening 17 ′ smaller than an area S 2 of the through hole 2 (processed part) in the main plane 1 b of the stainless steel substrate 1. Can do. As described above, the second gold plating unnecessary for the first gold plating layer 11 on the main plane 1b side of the stainless steel substrate 1 is used by using the mask in which the area S1 of the opening 17 ′ is smaller than the area S2 of the processing site. Formation of the layer is prevented. Therefore, it is possible to suppress the occurrence of a conventional plating formation cross section in which a thick plating layer is formed at the corners of the recess and the opening, which is advantageous for controlling the formation of the second gold plating layer. In addition, the accuracy of the mask to be used can be given a margin, and an inexpensive and simple plating layer can be formed. In this case, the area S1 of the opening 17 ′ of the mask 16 ′ can be appropriately set in consideration of the area of the processing site, the condition of the plating solution, the accuracy of the mask arrangement, and the like. It is desirable to set so as to be in the range of 90 to 50% of the opening area S2 of the processing site.
In the above example, the mask 16 has an opening 17 larger than the area S2 of the through hole 2 (processed part), but a gold plating pattern is not formed on the main plane 1a of the stainless steel substrate 1, When the gold plating pattern is formed only on the wall surface of the through hole 2 (processed part), the mask 16 having the same opening as the mask 16 'can be used.
The material of the masks 16 and 16 'is not particularly limited as long as it is electrically insulating, and may be a silicon mask for plating manufactured by Shin-Etsu Chemical Co., Ltd., for example.

The plating solution used in the second plating step may be either a cyan plating solution or a hydrochloric acid plating solution. There is no restriction | limiting in particular in the cyan type plating solution to be used, A well-known plating solution can be used. Moreover, the hydrochloric acid type plating solution to be used is not limited as in the first plating step, and a known plating solution can be used.
Although the thickness of the 2nd gold plating layer 12 to form can be suitably set according to the use of the pattern of the gold plating layer to form, in this invention, the total thickness with the 1st gold plating layer 11 is 1 micrometer or less. The thickness of the second gold plating layer 12 can be set to be a thin film.

  Next, in the peeling step, the first gold plating layer 11 in a region where the second gold plating layer 12 and the polymer compound layer 15 are not present is peeled off using an alkaline stripping solution. Thereby, the gold plating pattern 10 is formed in the desired part of the wall surface 2a of the through-hole 2 which is a process part, and the main plane 1a of the stainless steel substrate 1 (FIG.1 (E)). As described above, in the present invention, since the total thickness of the first gold plating layer 11 and the second gold plating layer 12 can be set to 1 μm or less, the thickness of the formed gold plating pattern 10 is increased. Compared with the thickness of the molecular compound layer 15, it can be less than 1/10.

Examples of the alkaline stripping solution used in the stripping process include Gold Stripper 645 manufactured by Evonik Degussa Japan Co., Ltd. and Enstrip AU-78M manufactured by Meltex Co., Ltd. In use, the first gold plating layer can be peeled off by spraying, dipping, or the like.
In the above embodiment, the gold plating pattern 10 is adjacent to a part of the polymer compound layer 15, but the gold plating pattern 10 may be formed adjacent to the polymer compound layer 15, Alternatively, the gold plating pattern 10 may be formed so as to be separated from the polymer compound layer 15. In the present invention, the pattern may be a desired line, a circle, an ellipse, a square, a pattern, or the like, and includes, for example, a desired electric wiring shape, a convex shape, or the like.

  In the present invention, since the first gold plating layer is formed on the entire surface of the pretreated stainless steel substrate using the hydrochloric acid plating solution in the first plating step, the stainless steel substrate and the first gold plating layer are formed. Adhesion is good. Further, in the polymer layer compound forming step, the polymer compound layer is provided by melting and pressing the polymer compound on the first gold plating layer, so that compared with the case where the polymer compound layer is directly formed on the stainless steel substrate. Good adhesion can be obtained, and a decrease in adhesion in the wet process, which is the subsequent formation of the second gold plating layer, is suppressed. Further, in the second plating step, the second gold plating layer is formed in a desired pattern only by mask plating only at a desired portion of the first gold plating layer, and then an alkaline stripping solution is used in the peeling step. Since the first gold plating layer is peeled and removed, erosion of the stainless steel substrate is prevented. Moreover, since there is no difference in ionization tendency between the first gold plating layer and the second gold plating layer, the second gold plating layer does not erode and the thickness of the second gold plating layer can be reduced. it can. Thereby, a thin film pattern of 1 μm or less can be formed on the stainless steel substrate.

The thickness of the gold plating pattern to be formed is preferably 0.15 μm or more from the viewpoint of reliability of electrical continuity, and is preferably 1 μm or less from the viewpoint of manufacturing cost using gold plating. In addition, since the formed gold plating pattern is a two-layer structure, both layers are gold-plated layers, so that a stable coating without causing a battery reaction between the layers is obtained. Furthermore, when the stainless steel substrate has a part that does not require the formation of a gold plating pattern, this processed part can be exposed, so that there is no hindrance to utilization according to the purpose of the processed part.
In addition, when a pattern of a gold plating layer is formed by a conventional method on a processed part formed on a stainless steel substrate by etching or pressing, the current density is high at the etched part of the processed part, and the gold plating layer is locally formed. It becomes a thick film. However, in the present invention, the first gold plating layer in the region where the second gold plating layer does not exist is peeled and removed using an alkaline stripping solution in the stripping step. As a result, the partial gold plating pattern covering the processing site is smooth and the gold plating layer is not locally thick.

In the above embodiment, the stainless steel substrate 1 having the through-hole 2 is used as a processing part. However, the processing part is not particularly limited. For example, as shown in FIG. 2, opposed main planes 21a and 21b. And a concave portion 22 composed of a bottom surface 22a and a wall surface 22b different from the main plane 21a. The shape of the recesses and grooves, which are processed parts formed on the stainless steel substrate by etching, pressing, etc., may be a desired line, circle, ellipse, square, pattern, etc., for example, desired electrical wiring Shape, convex shape, etc. are included.
Further, as the stainless steel substrate, a stainless steel substrate that does not include the above-described processed portion can also be used.

<Second Embodiment>
FIG. 3 is a process diagram for explaining another embodiment of a method for forming a polymer compound layer and a partial gold plating pattern on a stainless steel substrate.
This embodiment will be described as an example in which the same stainless steel substrate as the above-described stainless steel substrate 1 is used.
First, in the first plating step, a resist pattern is formed on the stainless steel substrate so that at least the processing site is exposed, and then the first gold plating layer is directly formed on the exposed stainless steel substrate surface using a hydrochloric acid plating solution. To do. That is, in the first plating step, pretreatment is performed on the stainless steel substrate 1 having the through holes 2 formed of the opposing main planes 1a and 1b and the wall surfaces 2a different from the main planes 1a and 1b as processing parts. Thereafter, resist patterns 36 and 36 'are formed on the main planes 1a and 1b so that the through holes 2 (processed portions) for forming the second gold plating layer and the portions for forming the polymer compound layer are exposed at least. .
The resist patterns 36 and 36 'can be formed, for example, by laminating a dry film resist and patterning it by photolithography. At this time, a part of the stainless steel substrate 1 is exposed for power supply in plating. For example, the outer peripheral portion of the stainless steel substrate 1 may be exposed, or the power feeding pattern provided on the outer peripheral portion may be exposed.

Next, the first gold plating layer 31 is formed on the exposed main planes 1a and 1b of the stainless steel substrate and the wall surface 2a constituting the through-hole 2 which is the processing site (FIG. 3A). The resist patterns 36 and 36 ′ after the pretreatment are formed early so that the passive film is not re-formed on the stainless steel substrate 1. Further, the transition time until the subsequent formation of the first gold plating layer 31 is also set to a range in which the passive film is not re-formed on the stainless steel substrate 1.
The first gold plating layer 31 is formed using a hydrochloric acid plating solution and can be the same as the formation of the first gold plating layer 11 in the first embodiment described above. Is omitted.
Next, in the polymer compound layer formation step, the polymer compound layer 35 is provided by melt-bonding the polymer compound at a desired site on the first gold plating layer 31 (FIG. 3B). The formation of the polymer compound layer 35 can be the same as the formation of the polymer compound layer 15 in the first embodiment described above, and a description thereof is omitted here.

Next, in the second plating step, masks 37 and 37 having openings 38 are placed (FIG. 3C), and mask plating using the masks 37 and 37 is performed at a processing site of the stainless steel substrate 1. The second gold plating layer 32 is formed in a desired pattern only on the first gold plating layer 31 covering the wall surface of a certain through-hole 2. Thereafter, the masks 37 and 37 are removed, and the resist patterns 36 and 36 'are peeled off (FIG. 3D). The formation of the second gold plating layer 32 can be the same as the formation of the second gold plating layer 12 in the first embodiment described above, and the description thereof is omitted here.
For stripping the resist patterns 36 and 36 ', an alkaline stripping solution can be used, but it is preferable to use an alkaline stripping solution that cannot strip and remove the first gold plating layer 31. This is to prevent gold ion recovery efficiency, which will be described later, if the first gold plating layer 31 is simultaneously peeled off together with the resist patterns 36, 36 '. The polymer compound layer 35 provided on the first gold plating layer 31 by melt-bonding is, for example, an alkaline system adjusted to a concentration of less than 10% so that the first gold plating layer 31 cannot be peeled and removed. It has sufficient peel resistance against the stripping solution.

Next, in the peeling step, the first gold plating layer 31 in a region where the second gold plating layer 32 and the polymer compound layer 35 are not present is peeled off using an alkaline stripping solution. Thereby, the gold plating pattern 30 is formed only on the wall surface 2a of the through-hole 2 which is a processing site (FIG. 3E).
In this embodiment, the resist patterns 36 and 36 ′ are preferably formed to be thicker than the first gold plating layer 31. This is to prevent the first gold plating layer 31 from climbing on the resist patterns 36 and 36 ′ and to facilitate the peeling and removal of the resist patterns 36 and 36 ′.
Further, the resist patterns 36 and 36 ′ may be removed before performing mask plating using the masks 37 and 37. FIG. 4 is a view showing a state in which the masks 37 and 37 are arranged after the resist patterns 36 and 36 ′ are peeled as described above, and corresponds to the above-described FIG. 3C.
Further, the first gold plating layer 31 is peeled and removed in the next peeling step without peeling off the resist patterns 36 and 36 ′ in the stage of FIG. 3D, and then the resist patterns 36 and 36 ′ are peeled off. May be.
Also in this embodiment, a stainless steel substrate having another processing site as shown in FIG. 2 can be used, and a stainless steel substrate not having a processing site can also be used.

  In the present invention, since the first gold plating layer is formed using a hydrochloric acid plating solution at a desired portion of the stainless substrate that has been pretreated in the first plating step, the stainless steel substrate and the first gold plating layer are formed. Adhesiveness with is good. Further, in the polymer layer compound forming step, the polymer compound layer is provided by melting and pressing the polymer compound on the first gold plating layer, so that compared with the case where the polymer compound layer is directly formed on the stainless steel substrate. Good adhesion can be obtained, and a decrease in adhesion in the wet process, which is the subsequent formation of the second gold plating layer, is suppressed. Further, in the second plating step, the second gold plating layer is formed in a desired pattern only by mask plating only at a desired portion of the first gold plating layer, and then an alkaline stripping solution is used in the peeling step. Since the first gold plating layer is peeled and removed, erosion of the stainless steel substrate is prevented. Moreover, since there is no difference in ionization tendency between the first gold plating layer and the second gold plating layer, the second gold plating layer does not erode and the thickness of the second gold plating layer can be reduced. it can. Thereby, a thin film pattern of 1 μm or less can be formed on the stainless steel substrate.

<Third Embodiment>
FIG. 5 is a process diagram for explaining another embodiment of a method for forming a polymer compound layer and a partial gold plating pattern on a stainless steel substrate.
This embodiment is an example in which the above-described stainless steel substrate 1 is used. Like the above-described first embodiment, after the stainless steel substrate 1 is pretreated in the first plating step, A first gold plating layer 11 is directly formed on the entire surface using a hydrochloric acid plating solution (FIG. 5A).

Next, in the mask forming step, the polymer compound is melt-pressed so that only a desired portion of the first gold plating layer 11 is exposed, and the plating mask 19 is provided on the main plane 1a side and the plating mask is provided on the main plane 1b side. 19 'is formed (FIG. 5B). As the polymer compound used for forming the plating masks 19 and 19 ', a compound that can dissolve and remove unnecessary portions of the plating masks 19 and 19' in the subsequent process and form the remainder as a polymer compound layer is used. For example, a solder resist whose main component is an acrylic resin called a permanent resist is used. In melt-bonding, a polymer compound film having a desired shape that exposes a portion for forming a second gold plating layer in a later step is placed on the first gold plating layer 11 so that the polymer compound can be pressed. At the temperature, for example, the temperature condition recommended by the manufacturer of the polymer compound film to be used (for example, about 100 to 150 ° C.), the polymer compound film is pressure-bonded to the first gold plating layer while heating, and then the manufacturer recommended The plating masks 19 and 19 'can be formed by curing under ultraviolet exposure conditions. Moreover, although the thickness of the plating masks 19 and 19 'can be set according to the thickness required for the polymer compound layer 15 formed in the post process, the thickness of the second gold plating layer 12 formed in the post process. Is preferably set so as to be thicker. This is because the second gold plating layer 12 is prevented from riding on the plating masks 19 and 19 ', and the unnecessary portions of the plating masks 19 and 19' can be easily dissolved and removed in a subsequent process.
The crimping conditions can be set in the range of 1 × 10 ^{5 to} 5 × 10 ⁵ N / m ² using, for example, a vacuum laminator. Further, ultrasonic vibration bonding or the like may be used at the time of melt-bonding.

Next, in the second plating step, the second gold plating layer 12 is formed on the first gold plating layer 11 through the plating masks 19 and 19 '(FIG. 5C). The plating solution used in the second plating step may be either a cyan plating solution or a hydrochloric acid plating solution, as in the first and second embodiments described above. The thickness of the second gold plating layer 12 to be formed can be appropriately set according to the use of the pattern of the gold plating layer to be formed. In the present invention, the thin film having a total thickness of 1 μm or less with the first gold plating layer 11 It is possible to set the thickness of the second gold plating layer 12 so that
Next, in the polymer compound layer forming step, unnecessary portions of the plating masks 19 and 19 ′ are dissolved and removed, and the remainder is positioned on the first gold plating layer 11 as the polymer compound layer 15 (FIG. 5D). )). Unnecessary portions of the plating masks 19 and 19 'can be dissolved and removed using, for example, an alkaline aqueous solution having a concentration of less than 10%.
Next, in the peeling step, the first gold plating layer 11 in a region where the second gold plating layer 12 and the polymer compound layer 15 are not present is peeled off using an alkaline stripping solution. Thereby, the gold plating pattern 10 is formed in the wall surface 2a of the through-hole 2 which is a process site | part, and the desired site | part of the main plane 1a of the stainless steel substrate 1 (FIG.5 (E)). Needless to say, the gold plating pattern 10 may be formed only on the wall surface 2a of the through-hole 2 which is the processing site.

Also in this embodiment, a stainless steel substrate having another processing site as shown in FIG. 2 can be used, and a stainless steel substrate not having a processing site can also be used.
In the first plating step, the first gold plating layer may be formed on a desired portion of the stainless steel substrate by using a resist pattern as in the second embodiment described above. In this case, in the mask formation process, the plating masks 19 and 19 ′ are formed so that a desired portion of the formed first gold plating layer is exposed with the resist pattern used in the first plating process remaining.

  In the present invention as described above, the first gold plating layer is formed on the entire surface of the stainless substrate that has been pretreated in the first plating step or on a desired site using the hydrochloric acid plating solution. 1 Adhesiveness with a gold plating layer is improved. In the mask formation process, a polymer compound is melt-compressed on the first gold plating layer to provide a plating mask, so that the adhesion is better than when a plating mask made of a polymer compound is directly formed on a stainless steel substrate. In addition, a reduction in the adhesion of the plating mask in the wet process, which is the subsequent formation of the second gold plating layer, is suppressed. Then, after the second gold plating layer is formed in the second plating step, unnecessary portions of the plating mask are dissolved and removed to form a polymer compound layer, so that a polymer compound layer having good adhesion to the stainless steel substrate is obtained. It is done. Finally, since the first gold plating layer is peeled and removed using an alkaline stripping solution in the stripping step, erosion of the stainless steel substrate in the step of forming the gold plating pattern and the polymer compound layer is prevented. Moreover, since there is no difference in ionization tendency between the first gold plating layer and the second gold plating layer, the second gold plating layer does not erode and the thickness of the second gold plating layer can be reduced. it can. Thereby, a thin film pattern of 1 μm or less can be formed on the stainless steel substrate.

The above-described embodiments of the present invention are examples, and the present invention is not limited to these embodiments.
In addition, the dimensions of the stainless steel substrate, the processing site, the first gold plating layer, the second gold plating layer, the polymer compound layer, the mask, and the like shown in each of the above drawings are described for convenience, and the present invention is described below. It is not limited.

Next, the present invention will be described in more detail by showing more specific examples.
[Example 1]
As a stainless steel substrate, a SUS316 material (150 mm × 150 mm) having a thickness of 0.15 mm was prepared.
<First plating process>
As a hydrochloric acid plating solution, a hydrochloric acid plating solution A having the following composition was prepared.
(Composition of hydrochloric acid plating solution A)
・ Metallic gold: 2.0 g / mL
・ Hydrochloric acid: 40 g / mL
・ Cobalt: 0.1 g / mL

As a pretreatment, the above stainless steel substrate was subjected to an alkali cleaning treatment (normal temperature, 30 seconds), and then a hydrochloric acid immersion treatment (immersion in a 10% hydrochloric acid aqueous solution for 30 seconds). After this pretreatment, washing and drying are performed, and then a dry film resist is laminated on both surfaces of the stainless steel substrate, and this dry film resist is patterned by photolithography to have 10 circular openings with a diameter of 3 mm and a thickness of 10 mm. A 15 μm resist pattern was formed. The stainless substrate on which the resist pattern was formed in this manner was immersed in the hydrochloric acid plating solution A for 10 seconds, washed with water, and then observed with a scanning electron microscope. As a result, the degree of occurrence of micropitting on the surface of the stainless substrate was measured in units. It was confirmed that the number was 2 or less per area (mm ² ).
Further, the stainless steel substrate on which the resist pattern was formed as described above was subjected to hydrochloric acid immersion treatment (immersion in a 10% aqueous hydrochloric acid solution for 30 seconds), then washed with water, and immediately after that, using the above hydrochloric acid plating solution A, Under the conditions, the first gold plating layer was formed on the exposed surface of the stainless steel substrate. In the formation of the first gold plating layer, the first gold plating layer is formed with a thickness of six types (sample 1-1 to sample 1-6) as shown in Table 1 below by adjusting the plating treatment time. did.
(Conditions for first gold plating)
・ Current density: 3A / dm ²
・ Processing time: 5 to 15 seconds

<Polymer compound layer forming step>
In the above six types of samples (Sample 1-1 to Sample 1-6), the first gold plating layer (10 on one side, 20 in total) formed on the stainless steel substrate in the circular opening having a diameter of 3 mm of the resist pattern Among them, on a total of 10 gold plating layers on one side, a sheet (thickness 25 μm) having a diameter of 3 mm made of a laminate of a thermoplastic polyimide resin and a polyimide resin as an adhesive layer is placed, and a heater is provided. A plate-type heater was heated to 230 ° C. and melt-bonded under pressure bonding conditions of 2.5 × 10 ⁵ N / m ² to form a polymer compound layer. In addition, since the thermoplastic polyimide resin used as the adhesive layer has a glass transition temperature of 215 ° C., the heating temperature at the time of the melt-bonding is set higher by 15 ° C. than the glass transition temperature.
Moreover, after forming a resist pattern, the sample (sample 1-7) which does not form said 1st gold plating layer was prepared. In Sample 1-7, the polymer compound layer was directly formed on the stainless steel substrate by melt-bonding under the same conditions as described above.

<Second plating process>
A cyan plating solution having the following composition was prepared as a cyan plating solution.
(Composition of cyan plating solution)
・ Metallic gold: 6.0 g / mL
・ Cobalt: 0.5g / mL
Next, a mask (material is silicon used for general-purpose plating) having five circular openings with a diameter of 2 mm was prepared. In Sample 1-1 to Sample 1-6, the polymer compound layer is not formed, and the first gold plating layer (circle having a diameter of 3 mm) is exposed at the center of the five circular openings of the resist pattern. The masks were placed on both sides of the stainless steel substrate so that the centers of the circular openings of the masks coincided. Further, in Sample 1-7, the center of the circular opening of the mask is formed at the center of the five circular openings of the resist pattern in which the stainless steel substrate (circular with a diameter of 3 mm) is exposed without forming the polymer compound layer. Were placed on both sides of the stainless steel substrate so that the two match. Then, the second gold plating layer (thickness: 0.25 μm) was formed under these conditions using the above cyan plating solution through these masks. The treatment time was appropriately set in the following range so that the thickness of the second gold plating layer was 0.25 μm.
(Conditions for second gold plating)
・ Current density: 12 A / dm ²
・ Processing time: 3 to 10 seconds
Thereafter, the mask was removed, an alkaline stripping solution (3% sodium hydroxide aqueous solution) was prepared as a stripping solution, a stainless steel substrate was immersed in the stripping solution (solution temperature 50 ° C.) for 30 seconds, and then washed with water. Thereby, the resist pattern was peeled and removed.

<Peeling process>
For Sample 1-1 to Sample 1-6, an alkaline stripping solution (Gold Stripper 645 manufactured by Evonik Degussa Japan Co., Ltd.) was used as the stripping solution, and a stainless steel substrate was applied to this stripping solution (liquid temperature 25-35 ° C.). It was immersed for 2 seconds and then washed with water. As a result, the second gold plating layer and the first gold plating layer in the region where the polymer compound layer does not exist are peeled off, and a circular gold plating pattern having a diameter of 2 mm and a polymer compound layer having a diameter of 3 mm are formed on the stainless steel substrate. We were able to.

<Evaluation>
(Adhesion test of polymer compound layer)
The stainless steel substrate on which the polymer compound layer and the gold plating pattern are formed is held in a high-temperature and high-humidity tank at 85 ° C. and 85% for 24 hours, and after returning to room temperature, any abnormality (swelling, peeling or cracking in the polymer compound layer) The presence or absence of such occurrence was observed with a microscope and is shown in Table 1 below.
(Gold plating pattern adhesion test)
The stainless steel substrate on which the polymer compound layer and the gold plating pattern are formed is held at 350 ° C. for 5 minutes, and after returning to room temperature, the gold plating pattern is observed for any abnormality (whether blistering or cracking) with a microscope. The results are shown in Table 1 below. In this adhesion test, the influence on the polymer compound layer by holding at 350 ° C. is ignored.
(Tape peeling test)
Using an adhesive tape (No. 600 manufactured by Sumitomo 3M Limited), a tape peeling test was performed on the polymer compound layer and the gold plating pattern, and the presence or absence of peeling of the polymer compound layer and the gold plating pattern was shown in Table 1 below. It was shown to.
(Substrate erosion)
The surface of the stainless steel substrate exposed by peeling the first gold plating layer in the peeling process was observed with a microscope, and the presence or absence of erosion was evaluated. The results are shown in Table 1 below.

  As shown in Table 1, in Sample 1-1 to Sample 1-6, the polymer compound layer can be formed on the stainless steel substrate, and the formed polymer compound layer is superior to the stainless steel substrate. Adhesion was shown. In Sample 1-1 to Sample 1-6, a partial gold plating pattern of a thin film of 1 μm or less can be directly formed on a stainless steel substrate, and the formed gold plating pattern has excellent adhesion to the stainless steel substrate. It was confirmed that there was no erosion of the stainless steel substrate. However, in Sample 1-5 and Sample 1-6, the time required for stripping the first gold plating layer in the stripping step is significantly longer than that of Sample 1-1 to Sample 1-4. Compared to 4, it took 2 times longer for sample 1-5 and 3 times longer for sample 1-6.

[Example 2]
A stainless steel substrate was prepared in the same manner as in Example 1.
<First plating process>
As in Example 1, the stainless steel substrate was pretreated, washed with water, and immediately after that, a resist pattern was formed. Immediately thereafter, the same hydrochloric acid plating solution A as in Example 1 was used, and the same as in Example 1. A first gold plating layer was formed on the exposed surface of the stainless steel substrate under plating conditions. In the formation of the first gold plating layer, the first gold plating layer is formed with a thickness of six types (sample 2-1 to sample 2-6) as shown in Table 2 below by adjusting the plating treatment time. did.

<Polymer compound layer forming step>
In the above six types of samples (Sample 2-1 to Sample 2-6), the first gold plating layer formed on the stainless steel substrate in the circular opening having a diameter of 3 mm of the resist pattern (10 on one side, 20 in total) Among them, on a total of 10 gold plating layers on one side, a sheet (thickness 25 μm) having a diameter of 3 mm made of a laminate of a thermoplastic polyimide resin and a polyimide resin as an adhesive layer is placed, and a heater is provided. A plate-type heater was heated to 230 ° C. and melt-bonded under pressure bonding conditions of 2.5 × 10 ⁵ N / m ² to form a polymer compound layer. In addition, since the thermoplastic polyimide resin used as the adhesive layer has a glass transition temperature of 215 ° C., the heating temperature at the time of the melt-bonding is set higher by 15 ° C. than the glass transition temperature.
Moreover, after forming a resist pattern, the sample (sample 2-7) which does not form said 1st gold plating layer was prepared. In Sample 2-7, the polymer compound layer was directly formed on the stainless steel substrate by melt-compression bonding under the same conditions as described above.

<Second plating process>
As a hydrochloric acid plating solution, a hydrochloric acid plating solution B having the following composition was prepared.
(Composition of hydrochloric acid plating solution B)
・ Metallic gold: 4.0 g / mL
・ Hydrochloric acid: 60 g / mL
・ Cobalt: 0.1 g / mL
As a result of observing with a scanning electron microscope, the stainless steel substrate in which the above resist pattern was formed before the plating treatment in the first plating process was immersed in the hydrochloric acid plating solution B for 10 seconds, washed with water, It was confirmed that the degree of occurrence of micropitting on the surface of the surface exceeded 5 (10 to 15) per unit area (mm ² ).

Next, a mask having a circular opening with a diameter of 2 mm (the material is silicon used for general-purpose plating) was prepared. In Samples 2-1 to 2-6, the polymer compound layer is not formed, and the first gold plating layer (circular with a diameter of 3 mm) is exposed at the center of the five circular openings of the resist pattern. The masks were placed on both sides of the stainless steel substrate so that the centers of the circular openings of the masks coincided. Further, in sample 2-7, the center of the circular opening of the mask is formed at the center of the five circular openings of the resist pattern in which the stainless steel substrate (circular with a diameter of 3 mm) is exposed without forming the polymer compound layer. Were placed on both sides of the stainless steel substrate so that the two match. And using said hydrochloric acid plating liquid B through these masks, the 2nd gold plating layer (thickness 0.25 micrometer) was formed on condition of the following. The treatment time was appropriately set in the following range so that the thickness of the second gold plating layer was 0.25 μm.
(Conditions for second gold plating)
・ Current density: 3A / dm ²
・ Processing time: 50-60 seconds
Thereafter, the mask was removed, and the resist pattern was peeled and removed in the same manner as in Example 1.

<Peeling process>
For Sample 2-1 to Sample 2-6, the exposed first gold plating layer was peeled off in the same manner as in Example 1. As a result, the second gold plating layer and the first gold plating layer in the region where the polymer compound layer does not exist are peeled off, and a circular gold plating pattern having a diameter of 2 mm and a polymer compound layer having a diameter of 3 mm are formed on the stainless steel substrate. We were able to.

<Evaluation>
In the same manner as in Example 1, the adhesion test, the tape peeling test and the substrate erosion were evaluated, and the results are shown in Table 2 below.

  As shown in Table 2, when the hydrochloric acid plating solution is used in the second plating step, the thickness of the first gold plating layer formed in the first plating step is preferably 0.015 μm or more. Further, in Sample 2-2 to Sample 2-6 in which the thickness of the first gold plating layer is 0.015 μm or more, a thin gold plating pattern of 1 μm or less is directly formed on the stainless steel substrate without causing corrosion of the stainless steel substrate. It was confirmed that the formed gold plating pattern showed excellent adhesion to the stainless steel substrate and there was no erosion of the stainless steel substrate. In Samples 2-2 to 2-6, the polymer compound layer can be formed on the stainless steel substrate, and the formed polymer compound layer exhibits excellent adhesion to the stainless steel substrate. It was. However, in Sample 2-5 and Sample 2-6, the time required for stripping the first gold plating layer in the stripping step is significantly longer than Sample 2-1 to Sample 2-4. Compared to 4, it took 2 times longer for sample 2-5 and 3 times longer for sample 2-6.

[Example 3]
Samples 3-1 to 3-corresponding to Sample 1-1 to Sample 1-7 in the same manner as in Example 1 except that a SUS316L material (150 mm × 150 mm) having a thickness of 0.15 mm was used as the stainless steel substrate. 7 was produced.
About the produced seven types of samples (Sample 3-1 to Sample 3-7), the adhesion test, the tape peeling test, and the evaluation of the substrate erosion were performed in the same manner as in Example 1. Sample 3-1 to Sample For 3-6, the same results as in Example 1 (no abnormality in the adhesion test, no peeling in the tape peeling test, no erosion of the stainless steel substrate) were obtained. In Samples 3-5 and 3-6, it was confirmed that the time required for peeling the first gold plating layer in the peeling step was significantly longer than that of Samples 3-1 to 3-4.

[Example 4]
Sample 4-1 to Sample 4 corresponding to Sample 2-1 to Sample 2-7 were performed in the same manner as in Example 2 except that a SUS316L material (150 mm × 150 mm) having a thickness of 0.15 mm was used as the stainless steel substrate. 7 was produced.
About the produced seven types of samples (Sample 4-1 to Sample 4-7), the adhesion test, the tape peeling test, and the evaluation of substrate erosion were performed in the same manner as in Example 1. The results (Sample 4-2 to Sample 4-6, in which the thickness of the first gold plating layer is 0.015 μm or more, obtained no abnormality in the adhesion test, no peeling in the tape peeling test, and no corrosion of the stainless steel substrate) were obtained. It was. In Sample 4-5 and Sample 4-6, it was confirmed that the time required for peeling the first gold plating layer in the peeling step was significantly longer than that of Sample 4-1 to Sample 4-4.

[Example 5]
Samples 5-1 to 5-1 corresponding to Sample 1-1 to Sample 1-7 are the same as Example 1 except that SUS304 material and SUS304L material (150 mm × 150 mm) having a thickness of 0.15 mm are used as the stainless steel substrate. Sample 5-7 (using SUS304 material) and Sample 5-1 ′ to Sample 5-7 ′ (using SUS304L material) were prepared.
For the 14 samples prepared (Sample 5-1 to Sample 5-7, Sample 5-1 'to Sample 5-7'), in the same manner as in Example 1, the adhesion test, the tape peeling test, and the substrate erosion were performed. As a result of the evaluation, Sample 5-1 to Sample 5-6 and Sample 5-1 ′ to Sample 5-6 ′ were the same as in Sample 1-1 to 1-6 of Example 1 (adhesion test). In the tape peeling test and no corrosion of the stainless steel substrate). In Sample 5-5, Sample 5-6, Sample 5-5 ', and Sample 5-6', the time required for stripping the first gold plating layer in the stripping step is Sample 5-1 to Sample 5-4. It was confirmed that it was significantly longer than Samples 5-1 ′ to 5-4 ′.

[Example 6]
Sample 6-1 corresponding to Sample 2-1 to Sample 2-7 was performed in the same manner as in Example 2 except that SUS304 material and SUS304L material (150 mm × 150 mm) having a thickness of 0.15 mm were used as the stainless steel substrate. Sample 6-7 and Sample 6-1 ′ to Sample 6-7 ′ (using SUS304L material) were prepared.
About the produced 14 types of samples (Sample 6-1 to Sample 6-7 and Sample 6-1 ′ to Sample 6-7 ′), in the same manner as in Example 1, the adhesion test, the tape peeling test, and the substrate When the erosion was evaluated, the same results as in Example 2 (Sample 6-2 to Sample 6-6 and Sample 6-2 ′ to Sample 6 in which the thickness of the first gold plating layer was 0.015 μm or more) No. 6 ′ showed no abnormality in the adhesion test, no peeling in the tape peeling test, and no corrosion of the stainless steel substrate. In Sample 6-5, Sample 6-6, Sample 6-5 ′, and Sample 6-6 ′, the time required for stripping the first gold plating layer in the stripping step is Sample 6-1 to Sample 6-4. It was confirmed that it was significantly longer than Samples 6-1 ′ to 6-4 ′.

  It can be utilized in various manufacturing fields that require the formation of a gold plating pattern on stainless steel.

DESCRIPTION OF SYMBOLS 1, 21 ... Stainless steel substrate 1a, 1b, 21a, 21b ... Main plane 2 ... Through-hole 12 ... Recess 10, 30 ... Gold plating pattern 11, 31 ... First gold plating layer 12, 32 ... Second gold plating layer 15, 35 ... polymer compound layer 16, 16 ', 37 ... mask 17, 17', 38 ... opening 19, 19 '... mask

Claims (3)

  The processing includes a main plane facing each other and a processing portion configured of a surface different from the main plane, and the processing is performed via a gold plating pattern positioned at least in the processing portion and a gold plating layer thinner than the gold plating pattern. And a high molecular compound layer positioned at a desired site excluding the site.   The stainless steel substrate according to claim 1, wherein the gold plating pattern is located only in the processed portion.   The stainless steel substrate according to claim 1 or 2, wherein a thickness of the gold plating pattern is less than 1/10 of a thickness of the polymer compound layer.

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