JP3634658B2 - Pattern substrate and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pattern substrate and a manufacturing method thereof, and more particularly to a substrate on which a pattern is formed by selectively plating on a resin substrate and a manufacturing method thereof.
[0002]
[Prior art]
The following methods are known as conventional plating methods on a resin substrate.
[0003]
That is, when a pattern is formed on a glass epoxy resin substrate used for a printed circuit board or the like, a catalyst nucleus such as Pd which is a reaction starting point of a plating reaction is formed on the substrate surface, and this is electroless copper plated. A copper plating layer is formed on the substrate in contact with the liquid. Furthermore, a protective resist with a desired pattern is formed on this copper plating layer by a photo-etching process, then unnecessary portions are etched away with a chemical solution, and a desired pattern is formed. Increase.
[0004]
Here, for the formation of the Pd catalyst nucleus in the above step, a wet process using a tin chloride aqueous solution and a palladium chloride aqueous solution or the like may be used. It may be formed on a process substrate.
[0005]
Also known is a pattern formation method that does not use a protective resist during etching used in the above process. For example, a layer composed of a metal compound and an oxalic acid compound is formed on a polymer substrate, and this is subjected to pattern exposure with light having a wavelength of 200 to 450 (nm) to form a catalyst layer. A method for forming a metal pattern on a substrate without using a protective resist by rinsing and removing the portion not to be washed with an alkaline solution and immersing the substrate in a plating bath of copper, cobalt, nickel, gold or the like is known. (JP-A-7-336018).
[0006]
[Problems to be solved by the invention]
However, conventional methods for forming a pattern on a resin substrate have the following problems. That is, when a metal layer is formed on the entire surface of the substrate using the wet or dry process as described above, the formation of a protective resist for patterning the metal layer and the etching process of the metal layer are omitted. The process is complicated by necessity.
[0007]
Further, the method described in JP-A-7-336018 is an excellent method capable of omitting the formation of the protective resist and the etching process of the metal layer, but according to the contents described in the same publication. For example, it is necessary to form a strike layer of 1 (μm) or more on the patterned catalyst core layer (in the same publication, on the seed metal). In addition, the bath temperature of the plating bath used to form the strike layer must be set at a temperature around room temperature in order to prevent damage to the patterned catalyst core layer. Although not specified in the publication, for example, when a copper strike layer of 1 (μm) or more is to be formed under such conditions, the plating time usually requires several tens of minutes to several hours. There is a problem that the processing time becomes long.
[0008]
The present invention has been made to solve the above problems, and the object is to form a metal pattern by plating on a resin substrate without using a patterned protective resist, Moreover, it is an object of the present invention to provide a layer structure and a manufacturing method capable of forming a plating layer having the same effect as the strike layer at a high speed.
[0009]
[Means for Solving the Problems]
For this reason, the present invention clarifies the layer structure of the plating layer and the activation process for effectively imparting selective catalytic activity on the resin substrate, and at least nickel on the resin substrate. In a method for producing a patterned substrate in which a phosphor plating layer and a palladium plating layer are laminated in this order by a wet plating method, the resin substrate surface is irradiated with excimer light on a desired pattern, and then has an amino group. The resin substrate is brought into contact with a silane coupling agent or amino-modified reactive silicone oil, and a catalyst for initiating an electroless plating reaction is captured and immobilized on the excimer light irradiation part. A receiving layer is formed, and the nickel / phosphorous plating layer is formed on the receiving layer by electroless plating.
[0010]
In the manufacturing method of the present invention, a nickel / phosphorous plating layer is formed on a first layer on a resin substrate, and a palladium plating layer is formed on a second layer by an electroless plating method. These two layers are continuously formed on a substrate. After that, for example, a heat treatment is performed for 10 minutes or more at an atmospheric temperature of 100 ° C. or higher, and a plating process is used to strengthen the adhesion between the substrate and the plating layer. At this time, a patterned catalyst layer is provided on the surface of the substrate in order to initiate metal deposition on the substrate by an electroless nickel / phosphorous plating bath. For this purpose, first, excimer light is applied to the desired pattern formation on the substrate surface through a mask having a pattern opposite to the desired pattern, and the substrate surface is micro-etched and generated by irradiation with excimer light. The activated oxygen is brought into contact with the surface. As a result, activated oxygen can be applied only to the portion where pattern formation is desired, and this activated oxygen can capture a silane coupling agent having an amino group or amino-modified reactive silicone oil. It becomes.
[0011]
Since these trapped coupling agents and silicone oil bind to the base material with the amino group facing outward, they should be brought into contact with an aqueous solution (for example, an aqueous palladium chloride solution) containing ions of metal species that can become catalyst nuclei. Thus, metal ions are captured by the amino group and become the starting point of the electroless plating reaction, and an arbitrary plating pattern can be formed on the substrate without using a protective resist.
[0012]
At this time, as a usable silane coupling agent having an amino group,
having one primary amine at the end of the structural formula, such as γ-aminopropyltriethoxysilane, and
Having one primary amine and one secondary amine in the structural formula as represented by N-β (aminoethyl) γ-aminopropyltrimethoxysilane,
Others can be suitably used.
[0013]
Similarly, usable amino-modified reactive silicone oils are:
The side chain of the polysiloxane R-NH ₂ group (R is _C n _{H 2n:} n is an integer) can be suitably used such as those introduced.
[0014]
In addition, the electroless palladium plating solution used for the lamination of the second layer is hydrogen as a side reaction product of the metal deposition reaction in order to minimize hydrogen attack into the first nickel / phosphorous plating layer. It is preferable to use a plating solution that does not contain a reducing agent that generates odor.
[0015]
When the plating layer is laminated on the resin substrate with the layer structure as described above using the manufacturing process as described above, the total film thickness of the nickel / phosphorous plating layer and the palladium plating layer should be 0.1 (μm) or more. It is sufficient to withstand the film stress when another metal species or resin is further laminated thereon. Furthermore, if the process of the present invention is used, even if the bath temperature of the electroless nickel / phosphorous plating solution used for forming the first layer is around 70 ° C., the patterned catalyst core layer can be formed in a short time without damaging it. Can do.
[0016]
Incidentally, by using the manufacturing process of the present invention, an electroless nickel / phosphorous plating layer is laminated on an epoxy resin at a bath temperature of 70 ° C. by 0.2 (μm) for about 3 minutes, and the palladium plating layer is heated at a bath temperature of 90 ° C. It takes about 2 minutes to laminate 0.15 (μm) at ℃, and even though the total film thickness at this time is 0.35 (μm), the underlayer for further metal layer lamination As a sufficient function.
[0017]
Thus, the present invention can economically perform selective imparting of catalytic activity to a resin substrate and formation of a metallized pattern without using a protective resist.
[0018]
Further, by laminating copper, silver, gold, platinum, and others on the palladium plating layer by plating, wiring, electrodes, protective films, etc. having arbitrary patterns can be easily formed. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
FIGS. 1A to 1E are schematic views of a typical film forming process of the present invention. FIG. 2 is a diagram in which a metal species is further laminated on the palladium plating layer of FIG. FIG. 6 is a schematic diagram showing a typical layer configuration when the function as a wiring or a protective film is emphasized.
[0021]
At this time, FIG. 1A is a schematic view showing a resin substrate that can be used in the present invention. As a material of the resin substrate 1, the main structure contains a resin composed of epoxy, polysulfone, fluorinated polymer, and polyimide. You can use what you want.
[0022]
FIG. 1B is a schematic diagram when excimer light is irradiated onto the resin substrate 1 from a light source (not shown) through a metal mask 2 having the same opening as a desired pattern.
[0023]
As a light source for excimer light, for example, a dielectric barrier discharge excimer lamp manufactured by USHIO INC. Having a peak of light emission distribution of wavelength at 172 (nm), and the like can be preferably used.
[0024]
In FIG. 1 (c), a substrate irradiated with excimer light in a pattern is immersed in an aqueous solution containing an amino group-containing silane coupling agent or an aqueous solution containing amino-modified reactive silicone oil. It is a schematic diagram when the molecule | numerator 3 of this is couple | bonded with the board | substrate in the pattern form.
[0025]
Here, as an example of a commercially available silane coupling agent having an amino group, KBE603 manufactured by Shin-Etsu Chemical Co., Ltd. (having one primary amine at the molecular terminal) or KBM603 manufactured by the same company (structural formula) Among them, those having one primary amine and one secondary amine) and others can be used preferably.
[0026]
In addition, as an example of a commercially available product of amino-modified reactive silicone oil, KF-861 and X-22-3939A manufactured by Shin-Etsu Chemical Co., Ltd. (an amino group was introduced into the side chain of polysiloxane) And the like can be suitably used.
[0027]
FIG. 1 (d) shows a catalyst core layer that is the starting point of the electroless plating reaction by bringing the pattern formed in FIG. 1 (c) into contact with an aqueous solution containing palladium chloride. It is a schematic diagram when the nickel / phosphorous plating layer 4 is formed by dipping in an electrolytic nickel / phosphorous plating solution.
[0028]
The electroless nickel / phosphorous plating solution used here can be used by any manufacturer as long as the deposited film stress is small.
[0029]
Here, as an example of a commercially available electroless nickel / phosphorous plating solution, Melplate Ni-1402 manufactured by Meltex (plating temperature 73 ° C., metal Ni concentration 5.8 g / L; L indicates liter), Others can be suitably used.
[0030]
FIG. 1E is a schematic view when a palladium plating layer 5 is further laminated on the nickel / phosphorous plating pattern as shown in FIG.
[0031]
The electroless palladium plating solution used here preferably contains a reducing agent that does not generate hydrogen as a main side reaction during palladium deposition. This is because, by strengthening the adhesion at the interface between the substrate and the plating layer by heat treatment, occlusion of hydrogen from the outside into the nickel / phosphorous plating thin film is the cause of increasing the risk of film destruction due to hydrogen occlusion. Because it becomes.
[0032]
As a reducing agent that can be used under such conditions, hydrazine, hydroquinone, sodium formate, citric acid, and others can be suitably used.
[0033]
Moreover, as an example of a commercial product that satisfies such conditions, PARED, which is an electroless palladium plating solution manufactured by Kojima Chemical Co., Ltd., and the like can be suitably used.
[0034]
As described above, the resin substrate subjected to pattern plating is heat-treated at an ambient temperature of 100 ° C. or higher. This heat treatment can reinforce the adhesion between the resin substrate and the plating layer.
[0035]
In addition, when the heat treatment is performed with the palladium plating layer formed on the top layer, not only the oxidation of the metal layer can be suppressed, but also the use of the characteristics of palladium that it is easy to activate when laminating more metal species. This is advantageous.
[0036]
FIG. 2 is a schematic view when another metal species is further laminated on the pattern-plated substrate subjected to the above-described heat treatment.
[0037]
Here, when a metal species such as copper, silver, and gold that has low wiring resistance is stacked on palladium, the characteristics as a conductive circuit pattern on the resin substrate are enhanced.
[0038]
For the lamination of these metals, either an electroless plating method or an electrolytic plating method may be used. A commercially available plating solution or the like can be used freely for the film formation.
[0039]
Examples of commercially available products that can be used include N.I. E. Electrocatalytic plating solution S-900 manufactured by Chemcat, electroless silver plating solution EL-Ag, electrogold plating solution K-710 Pure Gold manufactured by Kojima Chemical Co., Ltd. The agent copper grease CLX-A, a copper sulfate plating bath to which CLX-C is similarly added, electroless gold plating solution Dyne Gold EL-2 manufactured by Daiwa Kasei Co., Ltd., and others can be suitably used.
[0040]
In addition, when a metal species having excellent chemical resistance such as platinum or iridium is laminated on palladium, the function as a protective pattern on the resin substrate is enhanced.
[0041]
For the lamination, either an electroless plating method or an electrolytic plating method may be used, and commercially available plating solutions and others can be freely used for the film formation.
[0042]
Examples of commercially available products that can be used include N.I. E. Electroless platinum plating solution EL-Pt manufactured by Chemcat Corporation, as well as electrolytic platinum plating solution Pt-745, and the like can be preferably used.
[0043]
As described above, the present invention can form an arbitrary metal pattern on a resin substrate by using a wet plating method without using a protective resist, and also has a layer structure of nickel, phosphorus and palladium. Therefore, it is possible to give added value to the pattern to be formed by laminating various metal species on the upper part.
[0044]
On the other hand, regardless of the manufacturing process shown in the present invention, a schematic diagram in the case of pattern etching using a protective resist 8 on a 10 (μm) copper plating layer 7 laminated on the entire surface of a resin substrate is shown. 3 shows. In this case, not only the extra process of applying / peeling the protective resist is increased, but it is also necessary to carry out the etching of the thick film, and the process is wasteful and is not preferable.
[0045]
【Example】
Hereinafter, specific examples of the present invention will be described.
[Example 1]
A resin substrate having a main structure made of an epoxy resin was prepared, and a metal mask having a line-shaped opening of 50 (μm) was placed thereon, and excimer light having a center wavelength of 172 (nm) was irradiated.
[0046]
The irradiation conditions are as follows.
[0047]
Irradiation distance 5mm from substrate surface
Excimer lamp radiation intensity 5.5 (mW / cm ² )
Irradiation atmosphere Room temperature, atmospheric irradiation time 2 (min)
At this time, a solution prepared by dissolving 5 (g) of γ-aminopropyltriethoxysilane and ethanol mixed at a weight ratio of 1 to 1 in 1 (L) ion-exchanged water was prepared. The substrate irradiated with the pattern was immersed for 2 minutes and washed with ion-exchanged water.
[0048]
Next, an aqueous solution prepared by dissolving palladium chloride in ion exchange water to 0.5 (g / L) to pH 6.5 with sodium hydroxide is prepared, and the substrate is immersed for 2 minutes at room temperature. Then, after immersing in ion-exchanged water and removing an excess palladium aqueous solution, it was immersed in an electroless nickel / phosphorous plating solution.
[0049]
The electroless nickel / phosphorous plating solution used here is the above-mentioned Melplate Ni-1402 made by Meltex Co., Ltd., plated at a plating temperature of 73 ° C. for 3 minutes, and 0.25 (μm) on the resin substrate. A nickel-phosphorous plating layer was formed.
[0050]
Immediately after completion of electroless nickel / phosphorous plating, the substrate is immersed in ion-exchanged water heated to 50 ° C., and after removing the plating solution adhering to the substrate, the substrate is placed in an electroless palladium plating solution heated to 90 ° C. It was immersed and plated for 2 minutes, and a palladium plating layer was laminated to 0.15 (μm).
[0051]
The electroless palladium plating solution used here was formic acid as a reducing agent, and the pH of the bath was 6.
[0052]
After the Pd plating is completed, the substrate is sufficiently washed with ion exchange water, blown with nitrogen to remove ion exchange water adhering to the substrate, and then baked for 30 minutes in an air atmosphere at 130 ° C. A patterned substrate having the layer configuration shown in (e) was produced.
[0053]
In the plating pattern thus obtained, the same 50 (μm) line as the mask used was formed without disconnection.
[Example 2]
In Example 1, the above-mentioned trade name KBM603 was used in place of γ-aminopropyltriethoxysilane. Other conditions were plated in the same manner as in Example 1 to produce a patterned substrate having the layer structure shown in FIG.
[0054]
In the plating pattern thus obtained, the same 50 (μm) line as the mask used was formed without disconnection.
[Example 3]
In Example 1, the above-mentioned trade name KF-861 was used instead of γ-aminopropyltriethoxysilane. Other conditions were plated in the same manner as in Example 1 to produce a patterned substrate having the layer structure shown in FIG.
[0055]
In the plating pattern thus obtained, the same 50 (μm) line as that of the used mask was not broken or peeled off.
[Example 4]
On the palladium plating layer of the substrate having the layer structure shown in FIG. 1 (e) produced using the same manufacturing process as in Examples 1 to 3, the above-described electrolytic silver plating solution (trade name S-900) Was used to laminate a silver plating layer of 20 (μm), and a patterned substrate having the layer configuration shown in FIG. 2 was produced.
[0056]
At this time, no disconnection or separation was observed in the pattern formed on the substrate.
[Example 5]
An electroless platinum plating solution (trade name EL-Pt) described above was further formed on the palladium plating layer of the substrate having the layer structure shown in FIG. ) Was used to form a patterned substrate having the layer configuration shown in FIG.
[0057]
At this time, no disconnection or separation was observed in the pattern formed on the substrate.
[Example 6]
Except for preparing a resin substrate whose main structure is made of polysulfone resin, the same processing as in Examples 1 to 5 was performed. As a result, no disconnection or separation was observed in the pattern formed on the substrate.
[Example 7]
Except that a resin substrate having a main structure made of a fluorinated polymer was prepared, the same treatment as in Examples 1 to 5 was performed. As a result, no disconnection or separation was observed in the pattern formed on the substrate.
[Example 8]
Except that a resin substrate whose main structure is made of polyimide was prepared, the same processing as in Examples 1 to 5 was performed. As a result, no disconnection or separation was observed in the pattern formed on the substrate.
[Comparative Example 1]
As shown in FIG. 3, a copper plating layer having a thickness of 20 (μm) is formed on the entire surface of the epoxy resin substrate, a protective resist pattern having a width of 50 (μm) is formed thereon, and a metal pattern is formed by an etching process. When formed, disconnection and chipping were observed in some places in the copper pattern.
[0058]
【The invention's effect】
The present invention can form a metal pattern having a sufficient resolving power on a resin substrate without using a photo-etching process using a protective resist by employing the manufacturing process and the layer structure as described in detail above. .
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a film forming process and a layer structure of the present invention.
FIG. 2 is a schematic diagram showing a layer structure of the present invention.
FIG. 3 is a schematic diagram showing a comparative example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin substrate 2 Mask 3 Catalyst nucleus acceptance layer 4 Nickel * phosphorus plating film 5 Palladium plating film 6 Copper, silver, gold | metal | money, platinum, or iridium plating layer 7 Copper plating layer 8 which covered the whole board 8 Protective resist layer

Claims (5)

At least in the method for producing a patterned substrate in which a nickel / phosphorous plating layer and a palladium plating layer are laminated in this order by a wet plating method on a resin substrate,
Excimer light is irradiated on the surface of the resin substrate in a desired pattern, and then the resin substrate is brought into contact with a silane coupling agent having an amino group or reactive amino oil modified with amino, and the excimer light is irradiated. A receiving layer for capturing and immobilizing a catalyst for initiating an electroless plating reaction is formed on the irradiated portion, and the nickel / phosphorous plating layer is formed on the receiving layer by electroless plating. A method for manufacturing a pattern substrate. 2. The method for manufacturing a patterned substrate according to claim 1, wherein the excimer light has a peak of emission distribution at a wavelength of 172 (nm). 2. The method for manufacturing a patterned substrate according to claim 1, wherein one or more plating layers are further laminated on the palladium plating layer. 2. The pattern substrate manufacturing method according to claim 1, wherein the resin base contains a resin made of at least one of epoxy, polysulfone, fluorinated polymer, and polyimide. The pattern board produced using the manufacturing method in any one of Claims 1-4.

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