Plating method and method for manufacturing a wiring circuit board

Abstract

The present invention provides a plating method and a method for manufacturing a wiring circuit board that can reduce the cost required for the plating process. [Solution] In the plating method, a laminate 1 of stainless steel and copper or copper alloy is prepared, and a nickel underplating layer is simultaneously formed on a first plated portion provided on the stainless steel and a second plated portion provided on the copper or copper alloy using a hydrochloric acid-based electrolyte. In the manufacturing method of a wiring circuit board, a laminate of stainless steel and a conductor layer made of copper or copper alloy is prepared, and a first connection terminal and a second connection terminal are simultaneously formed on the laminate. In the formation of the first connection terminal, a nickel underplating layer is formed on the first terminal portion provided on the stainless steel using a hydrochloric acid-based electrolyte. In the formation of the second connection terminal, a nickel underplating layer is formed on the second terminal portion provided on the stainless steel using a hydrochloric acid-based electrolyte.

Description

[Technical Field]

[0001] This invention relates to a plating method and a method for manufacturing a wiring circuit board. [Background technology]

[0002] Laminates of dissimilar metals are sometimes used as electronic components. For example, in a wiring circuit board used in a drive device such as a hard disk drive, a stainless steel plate and a conductive layer made of copper or a copper alloy are formed with an insulating layer in between. The wiring circuit board is manufactured by plating predetermined portions of the stainless steel plate and the conductive layer (see, for example, Patent Document 1).

[0003] It is preferable that the plating treatment of the stainless steel sheet and the conductive layer be carried out simultaneously. However, a passivation film is formed on the surface of the stainless steel sheet. Therefore, it is not easy to plate the stainless steel sheet and the conductive layer at the same time.

[0004] In Patent Document 1, before plating a stainless steel plate, a voltage is applied between the stainless steel plate and the electrode so that the stainless steel plate acts as the anode and the electrode in the plating layer acts as the cathode. In this case, the passive film formed on the part to be plated is dissolved and removed by a reduction reaction. By performing such a passive film removal treatment (reverse electrolysis treatment) on the stainless steel plate in advance, the stainless steel plate and the conductive layer are plated simultaneously. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-210959 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In the plating method described in Patent Document 1, a reverse electrolytic treatment is performed on the material to be plated, which increases the number of processing steps and the number of parts in the plating apparatus. As a result, the cost required for the plating process increases.

[0007] The object of the present invention is to provide a plating method and a method for manufacturing a wiring circuit board that can reduce the cost required for the plating process. [Means for solving the problem]

[0008] Generally, when plating stainless steel, an electrolyte solution mainly composed of nickel chloride (Wood's bath) is used to remove the passive film on the surface. However, Wood's bath is highly corrosive and can damage stainless steel. Therefore, Patent Document 1 suggests that electrolyte solutions containing highly corrosive components such as chlorine should not be used.

[0009] When using a Wood bath for plating copper or copper alloys (hereinafter simply referred to as copper), it was believed that the copper would be more severely damaged than stainless steel. Furthermore, since a passive film is hardly formed on the surface of copper, there is no need to use a Wood bath in the plating process. For this reason, conventionally, when plating copper, an electrolyte solution mainly composed of nickel sulfate (Watt bath) has been used.

[0010] In the plating method described in Patent Document 1, an electrolyte mainly composed of nickel sulfate is used for plating stainless steel plates and copper. However, in the plating method described in Patent Document 1, it is necessary to perform a reverse electrolytic treatment on the stainless steel plate in advance in order to remove the passive film on the surface of the stainless steel plate.

[0011] The inventors of this invention, without being constrained by conventional technical biases, conducted repeated experiments and studies using various electrolytes and found that even when using a Wood bath as the electrolyte, it does not significantly damage the copper. Based on this finding, the inventors came up with the following configuration.

[0012] (1) The plating method according to the first invention includes preparing a laminate of stainless steel and copper or a copper alloy, and simultaneously forming a nickel underplating layer on a first plated portion provided on the stainless steel and a second plated portion provided on the copper or copper alloy using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate.

[0013] This plating method allows for the simultaneous formation of a nickel underplating layer on a first plated portion made of stainless steel and a second plated portion made of copper or a copper alloy by using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate. In this case, an increase in the number of steps required for the plating process is prevented. Therefore, the cost of the plating process can be reduced.

[0014] (2) Forming the undercoat plating layer may include forming the undercoat plating layer on the first plated portion and the second plated portion under the same plating conditions. In this case, it becomes possible to perform the plating treatment on the first plated portion and the second plated portion in the same plating tank. This makes it possible to further reduce the cost required for the plating treatment.

[0015] (3) The plating conditions may include current density or voltage. In this case, it becomes easier to form an undercoat on both the first and second plated parts simultaneously.

[0016] (4) Forming the undercoat may include applying a voltage to the first plated portion and the second plated portion using a common electrode. In this case, an increase in the number of parts required for plating is prevented. Therefore, the cost required for plating can be further reduced.

[0017] (5) The concentration of hydrochloric acid in the electrolyte may be 60 ml / L or more. In this case, the adhesion between the first plated part and the second plated part and nickel is improved. Thereby, it becomes easier to form the undercoat plating layer on the first plated part and the second plated part simultaneously.

[0018] (6) The plating method may further include forming an undercoat plating layer made of nickel on the undercoat plating layer formed on the first plated part and the second plated part. In this case, an undercoat plating layer having a sufficiently large thickness can be formed on the first plated part and the second plated part.

[0019] (7) The plating method may further include forming a plating layer made of gold (Au) on the undercoat plating layer formed on the first plated part and the second plated part. In this case, the corrosion resistance of the surfaces of the first plated part and the second plated part can be improved, and the wettability of the solder can also be improved.

[0020] (8) The laminate is a wiring circuit board in which a conductor layer made of stainless steel and copper or a copper alloy is laminated. The first plated part may be a first terminal part provided on the stainless steel, and the second plated part may be a second terminal part provided on the conductor layer. In this case, in the wiring circuit board, an undercoat plating layer made of nickel can be formed on the first terminal part made of stainless steel and the second terminal part made of copper or a copper alloy simultaneously.

[0021] (9) A method for manufacturing a wiring circuit board according to the second invention includes preparing a laminate of stainless steel and a conductor layer made of copper or a copper alloy, and simultaneously forming a first connection terminal and a second connection terminal on the laminate, wherein forming the first connection terminal includes forming a nickel underplating layer on the first terminal portion provided on the stainless steel using an electrolyte containing hydrochloric acid and nickel chloride hexahydrate, and forming the second connection terminal includes forming a nickel underplating layer on the second terminal portion provided on the copper or a copper alloy using an electrolyte containing hydrochloric acid and nickel chloride hexahydrate.

[0022] According to this method for manufacturing a wiring circuit board, by using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate, a nickel underplating layer is simultaneously formed on the first terminal portion made of stainless steel and the second terminal portion made of copper or a copper alloy. This allows the first and second connection terminals to be formed simultaneously. In this case, an increase in the number of steps required for manufacturing the wiring circuit board is prevented. Therefore, the cost of manufacturing the wiring circuit board can be reduced.

[0023] (10) Forming the first and second connection terminals may include forming the first and second connection terminals under the same plating conditions. In this case, the plating of the first terminal portion and the second terminal portion can be performed in the same plating bath. This makes it possible to further reduce the cost required for manufacturing the wiring circuit board.

[0024] (11) The plating conditions may include current density or voltage. In this case, it becomes easier to form the underplating layer on the first terminal portion and the second terminal portion simultaneously.

[0025] (12) Forming the first and second connection terminals may include applying a voltage to each of the first and second terminal portions using a common electrode. In this case, an increase in the number of components required for manufacturing the wiring circuit board is prevented. This makes it possible to further reduce the cost required for manufacturing the wiring circuit board.

[0026] (13) The concentration of hydrochloric acid in the electrolyte may be 60 ml / L or higher. In this case, the adhesion between the first plated portion and the second plated portion and nickel is improved. This makes it easier to form an undercoat on the first plated portion and the second plated portion simultaneously.

[0027] (14) Forming a first connection terminal further includes forming a nickel-based underplating layer on the underplating layer formed on the first terminal portion, and forming a second connection terminal further includes forming a nickel-based underplating layer on the underplating layer formed on the second terminal portion. In this case, underplating layers having a sufficiently large thickness can be formed on the first terminal portion and the second terminal portion.

[0028] (15) Forming a first connection terminal further includes forming a gold (Au) plating layer on the undercoat plating layer formed on the first terminal portion, and forming a second connection terminal further includes forming a gold (Au) plating layer on the undercoat plating layer formed on the second terminal portion. In this case, the corrosion resistance of the surfaces of the first and second connection terminals can be improved, as can the wettability of the solder. [Effects of the Invention]

[0029] According to the present invention, the cost required for plating can be reduced. [Brief explanation of the drawing]

[0030] [Figure 1]This is a schematic diagram showing the configuration of a plating apparatus used in a plating method according to an embodiment of the present invention. [Figure 2] This is an SEM image showing the appearance of the laminate in the example. [Figure 3] This is an SEM image showing the appearance of the laminate in the comparative example. [Figure 4] This is a plan view of the suspension substrate. [Figure 5] Figure 4 is a cross-sectional view of the suspension substrate along line AA. [Figure 6] This is an enlarged plan view of the tongue section seen from one side. [Figure 7] This is an enlarged plan view of the tongue section as seen from the other side. [Figure 8] Figures 6 and 7 show cross-sectional views of the tongue portion along line BB. [Figure 9] Figures 6 and 7 show cross-sectional views of the tongue portion along the CC line. [Figure 10] This is a block diagram showing the configuration of a plating system used in a manufacturing method for suspension substrates. [Figure 11] This is a cross-sectional view illustrating the manufacturing method of a suspension substrate. [Figure 12] This is a cross-sectional view illustrating the manufacturing method of a suspension substrate. [Figure 13] This is a cross-sectional view illustrating the manufacturing method of a suspension substrate. [Figure 14] This is a cross-sectional view illustrating the manufacturing method of a suspension substrate. [Figure 15] This is a cross-sectional view illustrating the manufacturing method of a suspension substrate. [Modes for carrying out the invention]

[0031] [1] Plating equipment (1) Configuration of the plating apparatus Hereinafter, a plating method and a method for manufacturing a wiring circuit board according to embodiments of the present invention will be described with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of a plating apparatus used in a plating method according to embodiments of the present invention. As shown in Figure 1, the plating apparatus 100 comprises a plating tank 110, a pair of transport rollers 120, a roller drive unit 130, a power supply roller 140, an electrode 150, a rectifier 160, and a control unit 170. The roller drive unit 130 and the rectifier 160 are controlled by the control unit 170.

[0032] In this embodiment, the member to be plated is a laminate 1 having a long shape. The laminate 1 has a stainless steel plate 2, an insulating layer 3, and a conductive layer 4 made of copper or a copper alloy. The insulating layer 3 includes, for example, polyimide. The stainless steel plate 2 is formed on one side of the insulating layer 3. The conductive layer 4 is formed on the other side of the insulating layer 3.

[0033] Multiple portions are provided on the surface of both the stainless steel sheet 2 and the conductor layer 4, where an undercoat plating layer is to be formed by the plating apparatus 100. Hereinafter, the portions on the laminate 1 where the undercoat plating layer is to be formed will be referred to as the plated portions. In particular, the portion on the surface of the stainless steel sheet 2 where the undercoat plating layer is to be formed will be referred to as the first plated portion, and the portion on the surface of the conductor layer 4 where the undercoat plating layer is to be formed will be referred to as the second plated portion.

[0034] An electrolyte is contained within the plating tank 110. The electrolyte mainly consists of nickel chloride hexahydrate (hereinafter simply referred to as nickel chloride) and hydrochloric acid. The concentration of nickel chloride in the electrolyte is preferably 100 g / L or more and less than 360 g / L. A nickel chloride concentration of 100 g / L or more improves current efficiency. Furthermore, a nickel chloride concentration of less than 360 g / L prevents uneven thickness of the underplating layer and suppresses cost increases.

[0035] The concentration of hydrochloric acid in the electrolyte is preferably 60 ml / L or more and less than 280 ml / L. A hydrochloric acid concentration of 60 ml / L or more improves current efficiency. It also improves adhesion between the first and second plated parts and nickel. This makes it easier to simultaneously form the undercoat on the first and second plated parts. A hydrochloric acid concentration of less than 280 ml / L prevents a decrease in nickel deposition efficiency.

[0036] The electrolyte temperature is, for example, 15°C or higher and less than 40°C, preferably 25°C. Keeping the electrolyte temperature below 40°C prevents metal corrosion caused by the generation of hydrogen chloride gas.

[0037] The laminate 1 is held between a pair of transport rollers 120. The pair of transport rollers 120 are rotated by a roller drive unit 130, thereby transporting the laminate 1. The plating tank 110 is provided with an inlet 101 and an outlet 102. The laminate 1 is brought into the plating tank 110 through the inlet 101 and discharged from the plating tank 110 through the outlet 102. In this case, within the plating tank 110, the laminate 1 is transported in the direction of arrow MD (hereinafter referred to as the transport direction) through the electrolyte. As a result, the plating apparatus 100 performs plating on the laminate 1 using a roll-to-roll method.

[0038] The plating time is adjusted by controlling the transport speed of the laminate 1. The plating time is, for example, 10 seconds or more and 300 seconds or less, but the embodiment is not limited thereto. The plating time is set appropriately according to the thickness of the undercoat plating layer to be formed. It is preferable that the upper limit of the plating time be set so as not to damage the first and second parts to be plated.

[0039] The power supply roller 140 is positioned outside the plating tank 110. The power supply roller 140 may be positioned upstream of the inlet 101 or downstream of the outlet 102. The power supply roller 140 also contacts the stainless steel plate 2 or the conductive layer 4 of the laminate 1. The power supply roller 140 is rotatably mounted so that no friction occurs between the power supply roller 140 and the laminate 1. The power supply roller 140 may be rotationally driven by a motor or the like so that a force is applied from the power supply roller 140 to the laminate 1 in the conveying direction.

[0040] The electrode 150 is positioned in the plating bath 110 so as to face the stainless steel plate 2 or conductive layer 4 of the laminate 1. For example, stainless steel, nickel, or platinum can be used as the material for the electrode 150. The power supply roller 140 is connected to the positive electrode of the rectifier 160, and the electrode 150 is connected to the negative electrode of the rectifier 160. The rectifier 160 applies a voltage between the laminate 1 and the electrode 150, which are in contact with the power supply roller 140. In this case, the laminate 1 becomes the cathode and the electrode 150 becomes the anode.

[0041] The current density in the electrolyte due to the rectifier 160 (current density between electrode 150 and laminate 1) is 2 A / dm 2 More than 50A / dm 2 It is preferable that the current density in the electrolyte by the rectifier 160 is 2 A / dm 2 As a result, the adhesion between the plated area and the underplating layer is improved. In addition, the current density in the electrolyte due to the rectifier 160 is 50 A / dm 2 By keeping the value below a certain level, it is prevented that the applied voltage between the laminate 1, which has high electrical resistance, and the electrode 150 becomes excessively large.

[0042] (2) Plating method The plating method for the laminate 1 using the plating apparatus 100 shown in Figure 1 will now be described. The operation of the plating apparatus 100 shown below is achieved by the control unit 170 controlling the roller drive unit 130 and the rectifier 160.

[0043] The laminate 1 is transported into the plating tank 110 through the entrance 101 by the transport roller 120 and transported in the transport direction. When the first plated portion of the stainless steel plate 2 and the second plated portion of the conductive layer 4 are transported into the plating tank 110, a voltage is applied between the first plated portion and the electrode 150 by the rectifier 160, and a voltage is also applied between the second plated portion and the electrode 150.

[0044] As a result, nickel is deposited simultaneously on the first and second plated areas. Consequently, a nickel-based undercoat is formed on the first and second plated areas. Hereinafter, this process of forming an undercoat will be referred to as electroplating. The thickness of the undercoat is, for example, 0.01 μm to 3.0 μm.

[0045] Thereafter, each time an untreated portion of the laminate 1 is transported into the plating tank 110, electroplating is performed on that portion. After a base plating layer is formed on the portion to be plated in this manner, a further base plating layer made of nickel may be formed on the base plating layer by electroplating in another plating tank (not shown). In this case, a base plating layer with a sufficiently large thickness can be formed on the portion to be plated.

[0046] Alternatively, after the undercoat plating layer is formed on the part to be plated, a gold (Au) plating layer (hereinafter referred to as the main plating layer) may be formed on the undercoat plating layer by electroplating in another plating tank (not shown). In this case, the corrosion resistance of the surface of the part to be plated can be improved, as can the wettability of the solder. The thickness of the main plating layer is, for example, 0.1 The size is between μm and 5.0 μm.

[0047] (3) Effects According to the plating method of this embodiment, by using a hydrochloric acid-based electrolyte, a nickel underplating layer can be simultaneously formed on a first plated part made of stainless steel and a second plated part made of copper or a copper alloy. In this case, an increase in the number of steps required for the plating process is prevented. Therefore, the cost required for the plating process can be reduced.

[0048] The undercoat plating layer is formed on both the first and second parts to be plated under the same plating conditions. Specifically, the undercoat plating layer is formed on both the first and second parts to be plated using the same current density (i.e., voltage). In this case, it becomes possible to perform the plating process on both the first and second parts to be plated in the same plating tank. This further reduces the cost required for the plating process. In addition, it becomes easier to form the undercoat plating layer on both the first and second parts to be plated simultaneously.

[0049] The undercoat plating layer is formed by applying a voltage to the first and second parts to be plated using a common electrode 150. In this case, an increase in the number of parts required for plating is prevented. Therefore, the cost required for plating can be further reduced.

[0050] [2] Example In the following Examples 1-4 and Comparative Examples 1-3, a base plating layer was formed on the stainless steel sheet 2 and the conductive layer 4 of the laminate 1 under various conditions using the plating apparatus 100, and the results were evaluated. The stainless steel sheet 2 is made of SUS304.

[0051] In Example 1, copper foil CF-T49A-DS-HD2-18 (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) was used as the conductive layer 4. As a pretreatment, the surface of the laminate 1 was degreased with a degreasing solution, and then soft etching was performed on the surface of the conductive layer 4 of the laminate 1. After soft etching, the laminate 1 was thoroughly washed with acid. After the pretreatment, electroplating was performed. In the electroplating process, a Wood bath was used as the electrolyte. The current density in the electrolyte was 2A. / dm 2 The electrolyte temperature was set to 25°C. The concentration of nickel chloride in the electrolyte was set to 240 g / L, and the concentration of hydrochloric acid was set to 120 ml / L. The plating time was set to 60 seconds.

[0052] In Example 2, the same pretreatment and electroplating process as in Example 1 were performed, except for the following: In the electroplating process, the current density in the electrolyte was set to 15 A / dm². 2 The electrolyte temperature was set to 30°C. The concentration of nickel chloride in the electrolyte was set to 280 g / L, and the concentration of hydrochloric acid was set to 140 ml / L. The plating time was set to 30 seconds.

[0053] In Example 3, the same pretreatment and electroplating process as in Example 2 were performed, except for the following: In the electroplating process, the current density in the electrolyte was set to 30 A / dm². 2 The electrolyte temperature was set to 20°C. The concentration of nickel chloride in the electrolyte was set to 200 g / L, and the concentration of hydrochloric acid was set to 100 ml / L.

[0054] In Example 4, the same pretreatment and electroplating process as in Example 1 was performed, except that HS1200 copper alloy foil (manufactured by JX Metals Corporation) was used as the conductive layer 4.

[0055] In Comparative Example 1, copper foil CF-T49A-DS-HD2-18 (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) was used as the conductive layer 4. After the same pretreatment as in Example 1, electroplating was performed. In the electroplating process, a Watt bath was used as the electrolyte. The current density in the electrolyte was set to 2 A / dm². 2The temperature of the electrolytic solution was set at 55°C. The concentration of nickel chloride in the electrolytic solution was set at 64 g / L, the concentration of nickel sulfate (hereinafter simply referred to as nickel sulfate) was set at 260 g / L, and the concentration of boric acid was set at 33 ml / L. The plating time was set at 60 seconds.

[0056] In Comparative Example 2, the same pretreatment and electrolytic plating processes as in Comparative Example 1 were performed, except for the following points. In the electrolytic plating process, the current density in the electrolytic solution was 15 A / dm 2 and the plating time was set at 30 seconds.

[0057] In Comparative Example 3, the same pretreatment and electrolytic plating processes as in Comparative Example 1 were performed, except that HS1200 copper alloy foil (manufactured by JX Metals Co., Ltd.) was used as the conductor layer 4.

[0058] The adhesion of the undercoat plating layers formed in Examples 1 to 4 and Comparative Examples 1 to 3 was evaluated by a cross-cut test. Table 1 shows the plating conditions and the evaluation results of the adhesion of the undercoat plating layers in Examples 1 to 4 and Comparative Examples 1 to 3.

[0059]

Table 1

[0060] As shown in Table 1, as a result of the cross-cut test, in Examples 1 to 4, the undercoat plating layer did not peel off from each of the stainless steel plate 2 and the conductor layer 4. On the other hand, in Comparative Examples 1 to 3, the undercoat plating layer did not peel off from the conductor layer 4, but the undercoat plating layer peeled off from the stainless steel plate 2.

[0061] Also, the adhesion of the undercoat plating layer was evaluated from the appearance of the laminate 1. Fig. 2 is a SEM (scanning electron microscope) photograph showing the appearance of the laminate 1 in the example. The left SEM photograph in Fig. 2 shows a cross-section of the boundary between the conductor layer 4 and the undercoat plating layer in Example 2. The right SEM photograph in Fig. 2 shows a cross-section of the boundary between the stainless steel plate 2 and the undercoat plating layer in Example 2.

[0062] As shown in Figure 2, when a Wood bath was used as the electrolyte, no voids were generated at either the boundary between the conductive layer 4 and the undercoat plating layer, or at the boundary between the stainless steel plate 2 and the undercoat plating layer. This confirmed that using a Wood bath as the electrolyte resulted in good adhesion of the undercoat plating layer.

[0063] Figure 3 is an SEM image showing the appearance of laminate 1 in the comparative example. The left SEM image in Figure 3 shows a cross-section of the boundary between the conductive layer 4 and the undercoat plating layer in comparative example 1. The right SEM image in Figure 3 shows a cross-section of the boundary between the stainless steel plate 2 and the undercoat plating layer in comparative example 1. Note that when forming the undercoat plating layer in Figure 3, the current density in the electrolyte was set to 4 A / dm². 2 The plating time was set to 150 seconds.

[0064] As shown in Figure 3, when a Watt bath was used as the electrolyte, no voids were generated at the boundary between the conductive layer 4 and the undercoat plating layer, but voids were generated at the boundary between the stainless steel plate 2 and the undercoat plating layer. This confirmed that when a Watt bath was used as the electrolyte, the adhesion of the undercoat plating layer was poor.

[0065] [3] Reference example (1) Stainless steel plate In the following reference examples 1 to 5, a base plating layer was formed on a stainless steel sheet under various conditions using the plating apparatus 100, and the results were evaluated. The stainless steel sheet was made of SUS304.

[0066] In Reference Example 1, the same pretreatment as in Example 1 was performed, followed by electroplating. A Wood bath was used as the electrolyte for the electroplating process. The current density in the electrolyte was set to 2 A / dm². 2 The electrolyte temperature was set to 25°C. The concentration of nickel chloride in the electrolyte was 240g. The concentration of hydrochloric acid was set to 120 ml / L. The plating time was set to 60 seconds.

[0067] In Reference Example 2, the same pretreatment and electroplating process as in Reference Example 1 were performed, except for the following points. In the electroplating process, the current density in the electrolyte was set to 15 A / dm². 2 The plating time was set to 30 seconds.

[0068] In Reference Example 3, the same pretreatment and electroplating process as in Reference Example 2 were performed, except for the following point: In the electroplating process, the current density in the electrolyte was set to 30 A / dm². 2 That's what I decided.

[0069] In Reference Example 4, after performing the same pretreatment as in Reference Example 1, electroplating was carried out. A Watt bath was used as the electrolyte for the electroplating process. The current density in the electrolyte was set to 2 A / dm². 2 The electrolyte temperature was set to 55°C. The concentration of nickel chloride in the electrolyte was 64 g / The volume was set to L, the concentration of nickel sulfate hexahydrate to 260 g / L, and the concentration of boric acid to 33 ml / L. The plating time was set to 60 seconds.

[0070] In Reference Example 5, the same pretreatment and electroplating process as in Reference Example 4 were performed, except for the following points. In the electroplating process, the current density in the electrolyte was set to 15 A / dm². 2 The plating time was set to 30 seconds.

[0071] The adhesion of the undercoat plating layers formed in Reference Examples 1 to 5 was evaluated by a cross-cut test. Table 2 shows the plating conditions and the evaluation results of the adhesion of the undercoat plating layers in Examples 1 to 5.

[0072] [Table 2]

[0073] As shown in Table 2, the cross-cut test results showed that in Reference Examples 1-3, the undercoat plating layer did not peel off from the stainless steel plate. On the other hand, in Reference Examples 4 and 5, the undercoat plating layer peeled off from the stainless steel plate. These results confirmed that when a Wood bath was used as the electrolyte, the adhesion of the undercoat plating layer was improved.

[0074] On the other hand, it was confirmed that when a Watt bath was used as the electrolyte, the adhesion of the undercoat plating layer was poor. This is thought to be because when a Watt bath is used as the electrolyte, the passivation film formed on the surface of the stainless steel plate cannot be removed.

[0075] (2) Conductor layer In the following reference examples 6 to 12, an undercoat plating layer was formed on the conductor layer under various conditions using the plating apparatus 100, and the results were evaluated.

[0076] In Reference Example 6, copper foil CF-T49A-DS-HD2-18 (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) was used as the conductive layer. After the same pretreatment as in Example 1, electroplating was performed. A Wood bath was used as the electrolyte for the electroplating. The current density in the electrolyte was set to 2 A / dm². 2 The electrolyte temperature was set to 25°C. The concentration of nickel chloride in the electrolyte was set to 240 g / L, and the concentration of hydrochloric acid was set to 120 ml / L. The plating time was set to 60 seconds.

[0077] In Reference Example 7, the same pretreatment and electroplating process as in Reference Example 6 were performed, except for the following points. In the electroplating process, the current density in the electrolyte was set to 15 A / dm². 2 Except for setting the plating time to 30 seconds, the same electroplating process as in Reference Example 6 above was performed.

[0078] In Reference Example 8, the same pretreatment and electroplating process as in Reference Example 7 were performed, except for the following points. In the electroplating process, the current density in the electrolyte was set to 30 A / dm². 2 That's what I decided.

[0079] In Reference Example 9, the same pretreatment and electroplating processes as in Reference Example 6 were performed, except that HS1200 copper alloy foil (manufactured by JX Metals Corporation) was used as the conductive layer.

[0080] In Reference Example 10, copper foil CF-T49A-DS-HD2-18 (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) was used as the conductive layer. After the same pretreatment as in Reference Example 1, electroplating was performed. In the electroplating process, a Watt bath was used as the electrolyte. The current density in the electrolyte was set to 2 A / dm². 2 The electrolyte temperature was set to 55°C. The concentrations of nickel chloride, nickel sulfate, and boric acid in the electrolyte were set to 64 g / L, 260 g / L, and 33 ml / L, respectively. The plating time was set to 60 seconds.

[0081] In Reference Example 11, the same pretreatment and electroplating process as in Reference Example 10 were performed, except for the following points. In the electroplating process, the current density in the electrolyte was set to 4 A / dm 2 The plating time was set to 30 seconds.

[0082] In Reference Example 12, the same pretreatment and electroplating processes as in Reference Example 10 were performed, except that HS1200 copper alloy foil (manufactured by JX Metals Corporation) was used as the conductive layer.

[0083] The adhesion of the undercoat plating layers formed in Reference Examples 6-12 was evaluated by a cross-cut test. Table 3 shows the plating conditions and the evaluation results of the adhesion of the undercoat plating layers in Reference Examples 6-12.

[0084] [Table 3]

[0085] As shown in Table 3, the cross-cut test results showed that in all of the reference examples 6 to 12, the undercoat plating layer did not peel off from the conductor layer. These results confirmed that good adhesion of the undercoat plating layer was achieved regardless of whether Wood's bath or Watt's bath was used as the electrolyte. This is thought to be because almost no passivation film was formed on the surface of the conductor layer.

[0086] [4] Method for manufacturing a wiring circuit board (1) Configuration of the suspension board A method for manufacturing a wiring circuit board according to an embodiment of the present invention will be described below. The wiring circuit board in the following embodiment is a suspension board with a circuit (hereinafter abbreviated as suspension board) used in the actuator of a hard disk drive device.

[0087] Figure 4 is a plan view of the suspension substrate. Figure 5 is a cross-sectional view of the suspension substrate 1A of Figure 4, taken along line AA. As shown in Figures 4 and 5, the suspension substrate 1A includes a long support substrate 10. The support substrate 10 is made of stainless steel.

[0088] A base insulating layer 11, for example, made of polyimide, is formed on the support substrate 10. Writing wiring patterns W1, W2, reading wiring patterns R1, R2, and heat assist wiring patterns H1, H2 are formed on the base insulating layer 11. The writing wiring patterns W1, W2, reading wiring patterns R1, R2, and heat assist wiring patterns H1, H2 are made of copper (Cu) or a copper alloy.

[0089] The writing wiring patterns W1, W2 and the heat assist wiring pattern H1 are formed on a region along one side of the support substrate 10. The heat assist wiring pattern H1 is positioned outside the writing wiring patterns W1, W2. The reading wiring patterns R1, R2 and the heat assist wiring pattern H2 are formed on a region along the other side of the support substrate 10. The heat assist wiring pattern H2 is positioned outside the reading wiring patterns R1, R2.

[0090] A magnetic head mounting section (hereinafter referred to as the tongue section) 50 is provided at one end of the support substrate 10 by forming a U-shaped opening 40. One end of the writing wiring patterns W1, W2, the reading wiring patterns R1, R2, and the heat assist wiring patterns H1, H2 each extend onto the tongue section 50. On the tongue section 50, a connection terminal 21 is provided at one end of the writing wiring pattern W1, and a connection terminal 22 is provided at one end of the writing wiring pattern W2. In addition, a connection terminal 23 is provided at one end of the reading wiring pattern R1, and a connection terminal 24 is provided at one end of the reading wiring pattern R2.

[0091] Furthermore, on the tongue portion 50, a land portion L1 is provided at one end of the heat assist wiring pattern H1, and a land portion L2 is provided at one end of the heat assist wiring pattern H2. As described later, the land portions L1 and L2 are connected to connection terminals 25 and 26 (Figure 7), respectively.

[0092] On the other end of the support substrate 10, a connection terminal 31 is provided at the other end of the writing wiring pattern W1, and a connection terminal 32 is provided at the other end of the writing wiring pattern W2. In addition, a connection terminal 33 is provided at the other end of the reading wiring pattern R1, and a connection terminal 34 is provided at the other end of the reading wiring pattern R2. Furthermore, a connection terminal 35 is provided at the other end of the heat assist wiring pattern H1, and a connection terminal 36 is provided at the other end of the heat assist wiring pattern H2.

[0093] A cover insulating layer 12, made of, for example, polyimide, is formed on the base insulating layer 11 so as to cover the writing wiring patterns W1, W2, reading wiring patterns R1, R2, and heat assist wiring patterns H1, H2, excluding the connection terminals 21-24 and 31-36. A metal coating, made of, for example, nickel, may be formed beneath the cover insulating layer 12 to cover the writing wiring patterns W1, W2, reading wiring patterns R1, R2, and heat assist wiring patterns H1, H2, respectively.

[0094] (2) Tongue Details of the tongue portion 50 will be described below. Figure 6 is an enlarged plan view of the tongue portion 50 as seen from one side (the same side as in Figure 4). Figure 7 is an enlarged plan view of the tongue portion 50 as seen from the other side (the opposite side from Figure 4). Figure 8 is a cross-sectional view of the tongue portion 50 in Figures 6 and 7 along line BB. Figure 9 is a cross-sectional view of the tongue portion 50 in Figures 6 and 7 along line CC.

[0095] As shown in Figure 6, the connection terminals 21-24 of the writing wiring patterns W1, W2 and the reading wiring patterns R1, R2 are not covered by the cover insulating layer 12. On the other hand, the land portions L1, L2 of the heat assist wiring patterns H1, H2 are covered by the cover insulating layer 12. A rectangular opening OP is formed in the base insulating layer 11. The connection terminals 21-24 are arranged so as to be aligned along one side of the opening OP.

[0096] As shown in Figure 7, an opening 10a is formed in the support substrate 10. The opening OP of the base insulating layer 11 overlaps with a portion of the opening 10a of the support substrate 10. Within the opening 10a, connection terminals 25 and 26 are provided on the lower surface of the base insulating layer 11. One end of connection terminal 25 overlaps with land portion L1 in Figure 6, and one end of connection terminal 26 overlaps with land portion L2 in Figure 6. The other ends of each connection terminal 25 and 26 are arranged to be aligned along one side of the opening OP of the base insulating layer 11.

[0097] In the following description, one end of the writing wiring patterns W1 and W2 will be referred to as terminal sections 21a and 22a, respectively. Similarly, one end of the reading wiring patterns R1 and R2 will be referred to as terminal sections 23a and 24a, respectively. Furthermore, the parts of the support substrate 10 formed within the opening 10a of the support substrate 10 will be referred to as terminal sections 25a and 26a. Terminal sections 25a and 26a are separated from the rest of the support substrate 10. As shown in Figure 8, a coating layer 60 consisting of multiple plating layers is formed to cover the side and top surfaces of each terminal section 21a to 24a. This forms the connection terminals 21 to 24.

[0098] As shown in Figure 9, tapered holes 11a and 11b are formed in the base insulating layer 11 on one end of terminal portion 25a and on one end of terminal portion 26a, respectively. Land portion L1 is provided so as to be in contact with the upper surface of the base insulating layer 11, the inner circumferential surface of hole 11a, and the upper surface of terminal portion 25a. Land portion L2 is provided so as to be in contact with the upper surface of the base insulating layer 11, the inner circumferential surface of hole 11b, and the upper surface of terminal portion 26a. A coating layer 60 consisting of multiple plating layers is formed to cover the side and lower surfaces of each terminal portion 25a and 26a. This forms the connection terminals 25 and 26.

[0099] A slider (not shown) equipped with a magnetic head is mounted on the upper surface of the tongue portion 50. The slider's connection terminals are electrically connected to the connection terminals 21-24 of the writing wiring patterns W1, W2 and the reading wiring patterns R1, R2. A heat assist device such as a laser diode is mounted on the lower surface of the slider so as to protrude to the lower side of the tongue portion 50 through the opening OP of the base insulating layer 11 and the opening 10a of the support substrate 10. The connection terminals of the heat assist device are electrically connected to connection terminals 25 and 26. When information is written to the magnetic disk by the magnetic head, the magnetic disk is heated by the heat assist device. This makes it possible to improve the density of information written to the magnetic disk.

[0100] (3) Plating system Figure 10 is a block diagram showing the configuration of a plating system used in the manufacturing method of the suspension substrate 1A. As shown in Figure 10, the plating system 200 includes the plating apparatus 100 of Figure 1, as well as a pretreatment apparatus 210, plating apparatuses 220, 230, 240, cleaning apparatuses 250, 260, 270, 280, and drying apparatus 290. The pretreatment apparatus 210 is located at the upstream end of the plating system 200 and performs pretreatment on the suspension substrate 1A. The pretreatment includes degreasing and cleaning with acid.

[0101] The plating apparatuses 100, 220, 230, and 240 are installed in this order from upstream to downstream. The plating apparatuses 220, 230, and 240 have basically the same configuration as the plating apparatus 100, except that the electrolyte is different. The plating layers formed sequentially by the plating apparatuses 100, 220, 230, and 240 constitute the coating layer 60 shown in Figures 8 and 9.

[0102] The plating apparatus 100 performs electrolytic plating (hereinafter referred to as strike plating) using a relatively high current for a short time on the parts of the suspension substrate 1A to be plated after pretreatment by the pretreatment apparatus 210, thereby forming a thin under-plating layer made of nickel on the parts to be plated. The cleaning apparatus 250 is provided between the plating apparatus 100 and the plating apparatus 220 and cleans the suspension substrate 1A with water after the strike plating by the plating apparatus 100.

[0103] The plating apparatus 220 performs electrolytic plating (hereinafter referred to as soft plating) using a relatively low current for a long period of time on the parts of the suspension substrate 1A to be plated after cleaning by the cleaning apparatus 250, thereby forming a thick under-plating layer made of nickel on a thin under-plating layer. In this case, an under-plating layer 62 with a sufficiently large thickness can be formed. The cleaning apparatus 260 is provided between the plating apparatus 220 and the plating apparatus 230 and cleans the suspension substrate 1A with water after the soft plating treatment by the plating apparatus 220.

[0104] The plating apparatus 230 performs a strike plating treatment on the portion of the suspension substrate 1A to be plated after cleaning by the cleaning apparatus 260 for a short time, thereby forming a thin main plating layer made of gold (Au) on a thick underplating layer. The cleaning apparatus 270 is provided between the plating apparatus 230 and the plating apparatus 240 and cleans the suspension substrate 1A with water after the strike plating treatment by the plating apparatus 230.

[0105] The plating apparatus 240 performs a soft plating treatment on the parts of the suspension substrate 1A to be plated after cleaning by the cleaning apparatus 270 for a long period of time, thereby forming a thick main plating layer made of gold (Au) on a thin main plating layer. The formation of the main plating layer improves the corrosion resistance of the surface of the parts to be plated and also improves the wettability of the solder. The cleaning apparatus 280 is located downstream of the plating apparatus 240 and cleans the suspension substrate 1A with water after the soft plating treatment by the plating apparatus 240. The drying apparatus 290 is located at the very downstream end of the plating system 200 and dries the suspension substrate 1A after cleaning by the cleaning apparatus 280.

[0106] (4) Method for manufacturing a suspension substrate Figures 11 to 15 are cross-sectional process views illustrating the manufacturing method of the suspension substrate 1A. The upper section of Figures 11 to 15 shows the manufacturing process of the connection terminal 21 shown in Figure 8. The lower section of Figures 11 to 15 shows the manufacturing process of the connection terminal 25 shown in Figure 8. The manufacturing method of the suspension substrate 1A will be explained below using the process cross-sectional views of Figures 11 to 15, along with the plating system 200 shown in Figure 10.

[0107] First, as shown in Figure 11, a suspension substrate 1A is prepared as the laminate 1. In the suspension substrate 1A, a support substrate 10 made of stainless steel and terminal portions 25a, 26a are formed on the lower surface of the base insulating layer 11. In addition, the conductive layers, namely the writing wiring patterns W1, W2, the reading wiring patterns R1, R2, and the heat assist wiring patterns H1, H2 (Figure 4), are formed on the upper surface of the base insulating layer 11. Note that in Figures 11 to 15, the terminal portions 22a to 24a, 26a, the writing wiring patterns W1, W2, the reading wiring patterns R1, R2, the heat assist wiring patterns H1, H2, and the cover insulating layer 12 are not shown.

[0108] A plating resist layer (not shown) is formed on the surface of the stainless steel plate and the conductor layer, excluding the first and second plated portions. In this example, terminal portions 25a and 26a are the first plated portions. One end (terminal portions 21a to 24a) and the other end of the writing wiring patterns W1 and W2 and the reading wiring patterns R1 and R2 are the second plated portions.

[0109] The manufacturing process for connectors 22-24 and 31-36 is the same as that for connector 21. The manufacturing process for connector 26 is the same as that for connector 25. Therefore, the following explanation will omit any mention of connectors 22-24, 26, and 31-36.

[0110] In the pretreatment device 210, pretreatment is performed on the suspension substrate 1A. Even in this case, as shown in Figure 11, the strong passivation film 5 formed on the surface of the support substrate 10 and the terminal portion 25a remains without being removed.

[0111] Next, as shown in Figure 12, the plating apparatus 100 performs strike plating on the portion of the suspension substrate 1A to be plated. This forms a nickel-based underplating layer 61 that covers the side and top surfaces of the terminal portion 21a. A nickel-based underplating layer 61 is also formed that covers the side and bottom surfaces of the terminal portion 25a. In this process, the passivation film 5 formed on the support substrate 10 and the terminal portion 25a is removed by the electrolyte. After the underplating layers 61 are formed, the suspension substrate 1A is cleaned in the cleaning apparatus 250.

[0112] Next, as shown in Figure 13, the plating apparatus 220 performs a soft plating treatment on the parts of the suspension substrate 1A to be plated. This forms a nickel-based underplating layer 62 that covers the sides and top surface of the underplating layer 61 of the terminal portion 21a. Similarly, a nickel-based underplating layer 62 is formed that covers the sides and bottom surface of the underplating layer 61 of the terminal portion 25a. The thickness of the underplating layer 62 is greater than the thickness of the underplating layer 61. The underplating layer 62 may be formed simultaneously on the terminal portions 21a and 25a under the same plating conditions. After the underplating layer 62 is formed, the suspension substrate 1A is cleaned in the cleaning apparatus 260.

[0113] Subsequently, as shown in Figure 14, the plated portion of the suspension substrate 1A is subjected to strike plating in the plating apparatus 230. This forms a main plating layer 63 made of gold (Au) that covers the side and top surfaces of the underplating layer 62 of the terminal portion 21a. Similarly, a main plating layer 63 made of gold (Au) is formed that covers the side and bottom surfaces of the underplating layer 62 of the terminal portion 25a. The main plating layer 63 may be formed simultaneously on the terminal portions 21a and 25a under the same plating conditions. After the main plating layer 63 is formed, the suspension substrate 1A is cleaned in the cleaning apparatus 270.

[0114] Next, as shown in Figure 15, a soft plating treatment is performed on the portion of the suspension substrate 1A to be plated in the plating apparatus 240. This forms a main plating layer 64 made of gold (Au) so as to cover the side and top surfaces of the main plating layer 63 of the terminal portion 21a. Similarly, a main plating layer 64 made of gold (Au) is formed so as to cover the side and bottom surfaces of the main plating layer 63 of the terminal portion 25a. The main plating layer 64 may be formed simultaneously on the terminal portions 21a and 25a under the same plating conditions. The thickness of the main plating layer 64 is greater than the thickness of the main plating layer 63.

[0115] A connecting terminal 21 is manufactured by forming a coating layer 60 consisting of undercoat plating layers 61, 62 and main plating layers 63, 64 on the terminal portion 21a. Similarly, a connecting terminal 25 is manufactured by forming a coating layer 60 consisting of undercoat plating layers 61, 62 and main plating layers 63, 64 on the terminal portion 25a. Finally, the suspension substrate 1A is cleaned in the cleaning device 280 and dried in the drying device 290. This completes the suspension substrate 1A.

[0116] (5) Effects According to the manufacturing method of the suspension substrate 1A of this embodiment, by using a hydrochloric acid-based electrolyte, a nickel-based underplating layer 61 is simultaneously formed on the terminal portions 25a and 26a made of stainless steel and on the terminal portions 21a to 24a, etc. made of copper or copper alloy. As a result, the connection terminals 25, 26 and the connection terminals 21 to 24 and 31 to 36 are formed simultaneously. In this case, an increase in the number of steps required to manufacture the suspension substrate 1A is prevented. Therefore, the cost required to manufacture the suspension substrate 1A can be reduced.

[0117] The formation of connection terminals 21-26 and 31-36 is carried out under the same plating conditions. Specifically, the formation of connection terminals 21-26 and 31-36 is carried out with the same current density (i.e., voltage). In this case, it becomes possible to perform the plating treatment of terminal sections 25a, 26a and terminal sections 21a-24a, etc. in the same plating bath. This makes it possible to further reduce the cost required to manufacture the suspension substrate 1A. In addition, it becomes easier to simultaneously form the undercoat plating layer 61 on terminal sections 25a, 26a and terminal sections 21a-24a, etc.

[0118] The connection terminals 21-26 and 31-36 are formed by applying a voltage to each terminal portion 21a-26a, etc., using a common electrode 150. In this case, an increase in the number of parts required for manufacturing the suspension board 1A is prevented. This makes it possible to further reduce the cost required for manufacturing the suspension board 1A.

[0119] [5] Other embodiments (1) In the above embodiment, the plating method according to the present invention is used to manufacture the suspension substrate 1A for the actuator of the hard disk drive device, but the embodiment is not limited thereto. The plating method according to the present invention may be used to manufacture other electronic components or circuit boards, or it may be used to manufacture other laminates 1 made of stainless steel and copper or copper alloy.

[0120] (2) In the above embodiment, an undercoat plating layer 62, a main plating layer 63, and a main plating layer 64 are formed on the undercoat plating layer 61 formed on the part to be plated, but the embodiment is not limited thereto. Some or all of the undercoat plating layer 62, the main plating layer 63, and the main plating layer 64 do not need to be formed.

[0121] (3) In the above embodiment, the formation of the undercoat on the first plated portion and the second plated portion is carried out under the same plating conditions, but the embodiment is not limited thereto. The formation of the undercoat on the first plated portion and the second plated portion may be carried out under different plating conditions. For example, the formation of the undercoat on the first plated portion and the second plated portion may be carried out under different current densities or voltages.

[0122] (4) In the above embodiment, the undercoat layer is formed by applying a voltage to the first plated portion and the second plated portion using a common electrode 150, but the embodiment is not limited thereto. The undercoat layer may also be formed by applying a voltage to the first plated portion and the second plated portion using separately provided electrodes 150. In this case, one housing portion 150 may be positioned to face the stainless steel plate 2, and the other electrode 150 may be positioned to face the conductor layer 4.

[0123] [6] Correspondence between each component of the claim and each part of the embodiment The following describes examples of the correspondence between each component of the claims and each part of the embodiments, but the present invention is not limited to the following examples. Various other elements having the configuration or function described in the claims can also be used as each component of the claims.

[0124] In the above embodiment, the stainless steel plate 2 is an example of stainless steel, the conductor layer 4 is an example of copper, a copper alloy, or a conductor layer, and the laminate 1 is an example of a laminate. Terminal portions 25a and 26a are examples of the first plated portion or first terminal portion, terminal portions 21a to 24a are examples of the second plated portion or second terminal portion, and under-plating layers 61 and 62 are examples of under-plating layers. Electrode 150 is an example of an electrode, main plating layers 63 and 64 are examples of plating layers, suspension substrate 1A is an example of a wiring circuit board, connection terminals 25 and 26 are examples of first connection terminals, and connection terminals 31 to 36 are examples of second connection terminals. [Explanation of Symbols]

[0125] 1…Laminate, 1A…Suspension substrate, 2…Stainless steel plate, 3…Insulating layer, 4…Conducting layer, 5…Passivation film, 10…Support substrate, 10a, OP…Opening, 11…Base insulating layer, 11a, 11b…Hole, 12…Cover insulating layer, 21a~26a…Terminal section, 21~26, 31~36…Connection terminal, 40…Opening, 50…Tang section, 60…Coating layer, 61, 62…Under-plating layer, 63, 64…Main plating layer, 100, 220, 230, 240…Plating apparatus, 101…Inlet, 102…Outlet, 110…Plating bath, 120…Conveyor roller, 130…Roller drive unit, 140…Power supply roller, 150…Electrode, 160…Rectifier, 170…Control unit, 200… Plating system, 210…Pre-treatment device, 250, 260, 270, 280…Cleaning device, 290…Drying device, H1, H2…Heat-assisted wiring patterns, L1, L2…Land area, R1, R2…Reading wiring patterns, W1, W2…Writing wiring patterns

Claims

1. To prepare a laminate of stainless steel and copper or a copper alloy, A plating method comprising simultaneously forming a nickel underplating layer on a first plated portion provided on stainless steel and a second plated portion provided on copper or a copper alloy using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate.

2. The plating method according to claim 1, wherein forming the undercoat plating layer includes forming the undercoat plating layer on the first plated portion and the second plated portion under the same plating conditions.

3. The plating method according to claim 2, wherein the plating conditions include current density or voltage.

4. The plating method according to any one of claims 1 to 3, wherein forming the undercoat plating layer includes applying a voltage to each of the first plated portion and the second plated portion using a common electrode.

5. The plating method according to any one of claims 1 to 4, wherein the concentration of hydrochloric acid in the electrolyte is 60 ml / L or more.

6. The plating method according to any one of claims 1 to 5, further comprising forming a nickel-based underplating layer on the underplating layer formed on the first plated portion and the second plated portion.

7. The plating method according to any one of claims 1 to 6, further comprising forming a gold (Au) plating layer on the under-plating layer formed on the first plated portion and the second plated portion.

8. The laminate is a wiring circuit board in which the stainless steel and a conductive layer made of copper or a copper alloy are laminated together. The first plated portion is a first terminal portion provided on the stainless steel, The plating method according to any one of claims 1 to 7, wherein the second plated portion is a second terminal portion provided in the conductor layer.

9. The process involves preparing a laminate of stainless steel and a conductive layer made of copper or a copper alloy, This includes simultaneously forming a first connection terminal and a second connection terminal on the laminate, Forming the first connection terminal involves forming a nickel underplating layer on the first terminal portion provided in the stainless steel using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate. A method for manufacturing a wiring circuit board, comprising forming the second connection terminal by using an electrolyte solution containing hydrochloric acid and nickel chloride hexahydrate to form a nickel underplating layer on the second terminal portion provided on the copper or copper alloy.

10. The method for manufacturing a wiring circuit board according to claim 9, wherein forming the first and second connection terminals includes forming the first and second connection terminals under the same plating conditions.

11. The method for manufacturing a wiring circuit board according to claim 10, wherein the plating conditions include current density or voltage.

12. A method for manufacturing a wiring circuit board according to any one of claims 9 to 11, wherein forming the first connection terminal and the second connection terminal includes applying a voltage to each of the first terminal portion and the second terminal portion using a common electrode.

13. A method for manufacturing a wiring circuit board according to any one of claims 9 to 12, wherein the concentration of hydrochloric acid in the electrolyte is 60 ml / L or more.

14. Forming the first connection terminal further includes forming a nickel-based underplating layer on the underplating layer formed on the first terminal portion, A method for manufacturing a wiring circuit board according to any one of claims 9 to 13, wherein forming the second connection terminal further comprises forming a nickel-based underplating layer on the underplating layer formed on the second terminal portion.

15. Forming the first connection terminal further includes forming a gold (Au) plating layer on the under-plating layer formed on the first terminal portion, The method for manufacturing a wiring circuit board according to any one of claims 9 to 14, wherein forming the second connection terminal further comprises forming a gold (Au) plating layer on the under-plating layer formed on the second terminal portion.

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