JP2011222798A - Metal pattern manufacturing method and metal pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal pattern manufacturing method which suppresses thickening due to plating and can keep good plating performance, and a metal pattern.SOLUTION: The metal pattern manufacturing method using electroless plating processing includes forming a pattern part using an ink which contains catalyst precursor for electroless plating on a substrate, and changing the catalyst precursor of the pattern part to a catalyst for electroless plating through an activation treatment. In this method, washing is performed using a cleaning fluid of 0.5 g/L or less catalyst precursor solubility and then the activation treatment is applied.

Description

  The present invention relates to a metal pattern manufacturing method and a metal pattern used for circuit formation by an ink jet method.

  Conventionally, formation of a metal pattern used in a circuit has been performed by a method using a resist material. That is, after applying a resist material on a thin metal layer and exposing the required pattern to light, the unnecessary resist is removed by development, the exposed thin metal is removed by etching, and the remaining resist portion is peeled off. As a result, a metal thin film on which a metal pattern was recorded was formed.

  However, this method is wasteful in terms of the efficiency of using raw materials, such as a wide variety of processes, and removal of unnecessary resist and thin metal, and improvement is required.

  On the other hand, a metal pattern forming method that draws a metal pattern directly by screen printing, ink jet printing or the like using ink containing metal nanoparticles having an average particle diameter of 100 nm or less has attracted attention (for example, Patent Document 1). reference).

  This metal pattern formation method is a method for forming a circuit by firing at a temperature of about 200 to 300 ° C. by utilizing the fact that the melting point is lowered by minimizing the particle size of the metal nanoparticles. Although this method certainly has advantages such as reduction in man-hours and improvement in raw material use efficiency, there is a problem that there are severe restrictions on the temperature and conditions in the post-treatment for reducing the electrical resistance in the metal pattern after firing. .

  There is a method in which a metal pattern is formed from a solution containing a reducing agent having reducibility under heating by using a metal salt in the form of metal ions without using metal nanoparticles and heating. However, since the complexing agent that coordinates and stabilizes the metal salt does not have sufficient performance, the reduction reaction of the metal salt easily proceeds and the liquid storage stability is poor.

  On the other hand, as a means for forming and depositing metal under mild conditions, a method of forming a metal pattern by utilizing an electroless plating technique has also been proposed. For example, a method is disclosed in which a circuit pattern is formed with an ink containing a catalyst capable of forming electroless plating, and then a metal is formed by electroless plating (for example, Patent Document 2 and Non-Patent Document 1). reference).

  In any of the above cases, the catalyst (precursor) is contained in the ink, and the ink is ejected onto the substrate to form the pattern. Thereafter, activation treatment and electroless plating are performed to form a metal pattern on the catalyst pattern.

  However, since the catalyst precursor has a certain degree of solubility in the activation treatment liquid, the catalyst precursor is dissolved and diffused from the pattern portion formed on the substrate. Due to this phenomenon, when a metal pattern is formed by electroless plating, the metal pattern becomes thicker than the desired line width (plating thickening phenomenon), which is a problem in forming a precise metal pattern. It was.

JP 2002-299833 A JP 7-131135 A

Proceedings of the 21st Electronics Packaging Society Conference p. 105 (2007)

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a metal pattern manufacturing method and a metal pattern in which plating thickness is suppressed and plating properties are not deteriorated.

  The above object of the present invention is achieved by the following configurations.

  1. A pattern part is formed on a substrate using an ink containing an electroless plating catalyst precursor, and the catalyst precursor in the pattern part is converted into an electroless plating catalyst by an activation treatment. In the manufacturing method which forms a metal pattern by a plating process, it wash | cleans with the washing | cleaning liquid whose solubility of this catalyst precursor with respect to a washing | cleaning liquid is 0.5 g / L or less, and performs the said activation process, The metal pattern manufacturing method characterized by the above-mentioned.

  2. 2. The method for producing a metal pattern according to 1 above, wherein the cleaning liquid contains positive metal ions, and the concentration of the positive metal ions is 2.5 mol / L or more.

3. 3. The method for producing a metal pattern according to 2 above, wherein the positive metal ion is at least one selected from Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ and Ba ²⁺ .

  4). 4. The method for producing a metal pattern according to any one of 1 to 3, wherein the catalyst precursor is a palladium metal complex.

  5. 5. The method for producing a metal pattern according to any one of 1 to 4, wherein the cleaning is performed with the cleaning liquid having a temperature of 10 ° C. or higher and 50 ° C. or lower.

  6). 6. A metal pattern formed using the metal pattern manufacturing method according to any one of 1 to 5 above.

  According to the present invention, it is possible to provide a metal pattern manufacturing method and a metal pattern in which plating thickness is suppressed and plating properties do not deteriorate.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  After the ink containing the catalyst precursor is ejected onto the substrate by the ink jet method and the pattern portion is formed, when the metal pattern is formed by activation treatment and electroless plating, the metal pattern becomes thicker than the desired line width. The cause of this phenomenon is estimated as follows. That is, it is presumed that the catalyst precursor on the substrate dissolves and diffuses in a small amount in the bath while the substrate is immersed in the bath of the activation process step after the pattern portion is formed by the inkjet method. For this reason, it was inferred that the catalyst precursor diffused in the bath was reattached on the substrate, resulting in thickening of the plating. In particular, the palladium metal complex of the catalyst precursor coexists with an alkali compound for increasing the solubility of the ink, and therefore, the dissolution and diffusion of the catalyst precursor in the aqueous medium easily proceeds. Further, in the pattern portion formation by the ink jet method, since the amount of ink applied on the substrate is small, the dissolution and diffusion tend to be further increased, so that it is presumed that plating thickening is likely to occur.

  Therefore, in the present invention, it has been found that the plating thickness can be improved by adding a washing step in which the catalyst precursor is not dissolved and the coexisting alkali compound can be removed before the activation treatment step. Usually, there is a method of reducing the plating forming ability as an improvement of the plating thickness. However, this method often inhibits normal plating on a portion having a small plating property such as a fine wire simultaneously with the improvement of the thickness. It was found that the method according to the present invention can improve the plating thickness without reducing the plating property.

  Specifically, after washing with a washing solution having a low solubility of the catalyst precursor in the washing solution, activation treatment is performed in the activation treatment step, and then electroless plating is performed. As a cleaning liquid in a normal cleaning process, water (pure water) that contains nothing is often used from the viewpoint of removing deposits and impurities and not adversely affecting the bath in the next process. However, when washing is performed using water, dissolution of the catalyst precursor and the like cannot be suppressed, and the plating thickness cannot be improved.

  Thus, as a result of intensive studies, it has been found that the use of a cleaning solution having a solubility of the catalyst precursor in the cleaning solution of 0.5 g / L or less can suppress the dissolution and diffusion of the catalyst precursor, thereby improving the plating thickness. It was.

  Here, the cleaning liquid in which the solubility of the catalyst precursor in the cleaning liquid is 0.5 g / L or less can be adjusted by changing the temperature, pH, type of solvent, etc., or by adding additives. In the present invention, it is preferable to prepare a cleaning solution having low solubility by allowing a certain amount or more of cation ions to be present in the cleaning solution.

  In particular, when the catalyst precursor was a palladium metal complex, the effect of improving the plating thickness appeared. This is presumed to be because in palladium metal complexes, when a large amount of positive metal ions are present in the cleaning liquid, dissolution and diffusion into the system are reduced. In addition, since the alkali compound can be removed by the cleaning liquid according to the present invention, it is considered preferable for the plating thickening.

  The specific configuration of the present invention will be described below.

《Metal pattern forming ink》
[Catalyst precursor]
In the present invention, the metal pattern forming ink (hereinafter also simply referred to as ink) used for pattern formation contains a catalyst precursor.

  The catalyst precursor in the present invention means a compound before being modified into an electroless plating catalyst by an activation treatment step. Specifically, it is a metal salt compound, preferably a palladium metal salt, more preferably a palladium metal complex. In the present invention, the palladium metal complex is preferably complexed with a palladium metal salt and a complexing agent.

  Examples of the catalyst precursor applicable to the present invention include palladium fluoride, palladium chloride, palladium bromide, palladium iodide, palladium nitrate, palladium sulfate, palladium acetate, palladium acetoacetate, palladium trifluoroacetate, palladium hydroxide. , Palladium oxide, palladium sulfide and the like, among which palladium chloride is preferable.

  The content of the catalyst precursor in the ink is preferably 0.01% by mass or more and 1.0% by mass or less. If the concentration of the catalyst precursor is 0.01% by mass or more, the necessary activity of the electroless plating reaction can be obtained in the electroless plating treatment step. It is preferable in that the stability of the palladium metal salt can be maintained. When a palladium metal salt is used as the catalyst precursor, it is preferably insoluble in water, so that it is dissolved in an acid. In this case, the acid used is preferably an inorganic acid, and examples thereof include hydrochloric acid, sulfuric acid, and nitric acid. Hydrochloric acid is preferable in terms of solubility. As the usage-amount of an inorganic acid, 5 mass%-30 mass% of palladium metal salt are preferable.

[Complexing agent]
Examples of the complexing agent applicable to the ink according to the present invention include compounds capable of forming a complex with the catalyst precursor. Examples of the compound include organic acids having a carboxyl group, and examples thereof include oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, tartaric acid, and citric acid. And it is preferably an amine compound or a nitrogen-containing heterocyclic compound. An amine compound is a compound in which one or more hydrogen atoms of ammonia are substituted with a hydrocarbon residue R, and is a complexing agent for Pd ions. In the present invention, ammonia is also included. The amine retains an unshared electron pair on the N atom and tends to complex with palladium ions. As amines, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, pyridine, 2-aminopyridine, 3-aminopyridine , 4-aminopyridine, ethylenediamine, ethanolamine, triethanolamine, linear amine compounds such as ethylenediaminetetraacetic acid, and cyclic amine compounds. Examples of the nitrogen-containing heterocyclic compound include pyridine, bipyridine, phenanthroline and the like.

  In the ink according to the present invention, the molar ratio of the catalyst precursor to the complexing agent is preferably in the range of 1: 0.5 or more and 1:10 or less. By setting the molar ratio of the catalyst precursor and the complexing agent to 1: 0.5 or more, the ratio of the complex formed by the catalyst precursor and the complexing agent is increased, so that the solubility in the ink and the reduction reactivity are increased. Becomes better. Moreover, it is preferable when the molar ratio is 1:10 or less in order to suppress reaction inhibition by an excessive complexing agent.

  In order to improve the solubility and storage stability of the complex formed with the catalyst precursor and the complexing agent in the ink, it is preferable to adjust the pH of the ink to a range of 8.0 or more, and more preferably pH 10. 0-14.0. The complex formed by the palladium metal salt and the complexing agent is preferably formed at a pH of 8.0 or higher because the formation proceeds more easily as the pH of the ink is more alkaline. In combination with a non-ink-absorbing resin substrate, the higher the pH of the ink, the better the adhesion and the better.

  In order to adjust the pH in the ink to be alkaline, an alkali agent is added. The alkali agent is not particularly limited, but sodium hydroxide and potassium hydroxide are preferable. As an addition amount, an amount necessary for adjusting to the pH value is added. Therefore, the neutralized salt formed by the added acid and alkali is contained in the ink. This neutralized salt is preferably dissolved with ink.

  As a pH measurement method, for example, a pH value at 25 ° C. is measured using a digital pH meter HM-30S manufactured by Toa Denpa Kogyo Co., Ltd.

[Ink solvent]
As the solvent applicable to the ink according to the present invention, an aqueous liquid medium is preferably used from the viewpoint of solubility of the palladium metal salt and the complexing agent, and the aqueous liquid medium is a mixture of water and a water-soluble organic solvent. A solvent is more preferably used. The composition of these solvents is preferably selected in consideration of the dissolved state of the complex formed with the palladium metal salt and the complexing agent.

  Examples of the water-soluble organic solvent preferably used include alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, etc.) and polyhydric alcohols (for example, ethylene glycol, diethylene glycol). , Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, etc.), polyhydric alcohol ethers (eg, ethylene glycol monomethyl ether) , Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol Cole monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol Monophenyl ether, propylene glycol monophenyl ether, etc.), amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethyl) Tetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc.), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocyclics (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.), sulfoxides (for example, dimethyl sulfoxide, etc.) and the like.

  A simple catalyst solution containing only water as a solvent is not suitable as an ink-jet ink. The presence of the organic solvent gives an appropriate viscosity (viscosity) for the ink to be stably ejected from the inkjet head, and the viscosity can be adjusted in the range of 1.5 to 30 mPa / s. Further, in order to avoid solidification and ejection failure in the head nozzle due to volatilization of the moisture of the ink, moisturization is imparted, and the surface tension of the ink is adjusted to 25 to 50 mN / m suitable for the ink jet system with an organic solvent. It is also important to make adjustments. Therefore, the organic solvent is preferably contained in the ink in an amount of 5 to 90% by mass, and more preferably 30 to 80% by mass. Moreover, as a boiling point of an organic solvent, 80 degreeC or more and 250 degrees C or less are preferable at the point of moisture retention and drying property.

[Surfactant]
Examples of the surfactant applicable to the ink according to the present invention include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl phosphates, and polyoxyalkylene alkyl ether phosphates. , Anionic surfactants such as fatty acid salts, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, acetylene glycols, polyoxyethylene-polyoxypropylene block copolymers, glycerin esters , Surfactants such as sorbitan ester, polyoxyethylene fatty acid amide and amine oxide, and cationic surfactants such as alkylamine salts and quaternary ammonium salts.

[Other various additives]
The ink according to the present invention can contain various conventionally known additives in other metal pattern forming inks as required. For example, fluorescent brighteners, antifoaming agents, lubricants, preservatives, thickeners, antistatic agents, matting agents, water-soluble polyvalent metal salts, acid bases, pH adjusters such as buffers, antioxidants, surfaces Tension modifiers, non-resistance modifiers, rust inhibitors, inorganic pigments and the like can be mentioned.

"substrate"
In the metal pattern formation using the ink according to the present invention, the substrate on which the metal pattern is formed is not particularly limited as long as it has insulating properties. For example, from a highly rigid material such as glass or ceramics, PET The film-like thing comprised from resin, such as (polyethylene terephthalate) and a polyimide, is mentioned.

  Among them, it is particularly preferable to use a non-ink-absorbing resin substrate in the metal pattern forming method of the present invention. Here, non-ink absorbability means that there is substantially or no dissolution or swelling when brought into contact with ink. By using a non-ink-absorbing resin substrate, particularly a resin film, as the base material, excellent flexibility can be obtained and application to a wide range of fields becomes possible. In addition, by using a non-ink-absorbing substrate, it is possible to form a highly precise metal pattern by suppressing the expansion and contraction of the substrate in the process of forming the metal pattern.

  The non-ink-absorbing resin is not particularly limited as long as it has insulating properties. For example, a polyester resin, a diacetate resin, a triatesate resin, a polycarbonate resin, a polyvinyl chloride resin, a polyimide resin The film-like thing comprised from resin, such as PET (polyethylene terephthalate) and a polyimide, among these is preferable, More preferably, it is a polyimide film.

  The substrate used in the present invention may be subjected to surface modification treatment from the viewpoint of improving adhesion. Similarly, an undercoat layer may be provided on the substrate. Examples of the material for the undercoat layer include a coupling agent such as a silane coupling agent.

<Metal pattern formation process>
The metal pattern forming method using the ink in the present invention is performed as follows.

1) a pattern part forming step for forming a pattern part using an ink containing a catalyst precursor;
2) A cleaning step using the cleaning liquid according to the present invention to clean the pattern portion,
3) an activation treatment step for converting the catalyst precursor into a catalyst;
4) An electroless plating process for generating metal with an electroless plating solution.

  Thereafter, a metal pattern having an arbitrary thickness may be formed in the electroplating process.

  Here, the pattern portion referred to in the present invention means a portion where ink ejected on the substrate is present.

[Pattern formation process]
In the present invention, the method for forming the pattern portion is preferably an ink jet method in which ink is ejected from the ink jet head onto the substrate to form the pattern portion. The size of the ink droplets to be ejected is not particularly limited, but in the case of circuit wiring or the like, it is necessary to form fine lines, so that it is preferably 50 pl or less, more preferably 20 pl or less It is. The inkjet head is not particularly limited, and either a piezo-type or a thermal-type head can be used.

  As a method of drying the pattern portion after forming the pattern portion, it is preferable to use a drying means such as heating or air blowing from the viewpoint of shortening the time.

(Washing process)
The metal pattern manufacturing method of the present invention is characterized in that the pattern portion is immersed in a cleaning solution for cleaning.

  In the cleaning liquid according to the present invention, the solubility of the catalyst precursor in the cleaning liquid is 0.5 g / L or less. By setting the solubility of the catalyst precursor at the time of pattern portion cleaning to 0.5 g / L or less, it becomes difficult for the catalyst precursor to dissolve in the cleaning liquid, and it is effective in suppressing plating thickness. The solubility here means the solubility at the same temperature as the temperature of the washing step.

  As a method for measuring the solubility defined in the present invention, after removing the solvent from the ink by heating or the like, the catalyst precursor taken out is put into a cleaning solution, stirred and dissolved, and then the undissolved catalyst precursor is removed. It was determined by quantifying the amount of catalyst precursor contained in the cleaning liquid. The solubility in the catalyst precursor is more preferably 0.3 g / L or less, and further preferably 0.1 g / L or less.

  Further, the solubility of the catalyst precursor varies depending on the temperature of the cleaning liquid, but the temperature of the cleaning liquid is preferably 10 to 50 ° C. When the temperature of the cleaning liquid is within the range specified in the present invention, the solubility of the catalyst precursor can be easily adjusted to 0.5 g / L or less, and the ability to remove other impurities is also improved.

<Cleaning liquid>
The cleaning liquid according to the present invention may be aqueous or non-aqueous, but is preferably a solution composed of an aqueous solvent. This is because the ink according to the present invention may contain a large amount of inorganic salt or alkali compound, and the efficiency of removing these is high.

  As a method for adjusting the cleaning liquid according to the present invention to the solubility range defined in the present invention, it is preferable to contain positive metal ions in water. It is presumed that the more the positive metal ions are present in the cleaning liquid, the more difficult the catalyst precursor is dissolved in the cleaning liquid, and the diffusion of the catalyst precursor is suppressed.

  At this time, the concentration of positive metal ions is preferably 2.5 mol / L or more, more preferably 5.0 mol / L or more. This is because by setting the concentration of the positive metal ion to 2.5 mol / L or more, the catalyst precursor becomes difficult to dissolve in the cleaning liquid, and it is effective to suppress the plating thickness.

As the applicable positive metal ions present invention, for ^{example, Li +, Na +, K} +, Mg 2+, Ca 2+, Ba 2+ are preferred. More preferred are Na ⁺ and K ⁺ . These positive metal ions may coexist. From the viewpoint of solubility in water and the like, the counter anion is preferably a halogen ion. Specific compounds in actual use include lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, sodium thiosulfate, sodium nitrite, sodium hydroxide, potassium chloride, Examples thereof include potassium bromide, potassium iodide, potassium carbonate, potassium hydroxide, magnesium chloride, calcium chloride, barium chloride, and barium acetate. Of these, sodium chloride and potassium chloride are preferable from the viewpoint of dissolving cation metal ions and not adversely affecting the catalyst precursor.

[Activation process]
The activation treatment according to the present invention means a treatment for converting the catalyst precursor into a catalyst capable of electroless plating.

In the present invention, the electroless plating reaction is more activated by performing the activation treatment before the electroless plating treatment step. In other words, after the ink containing the catalyst in a dissolved state is discharged onto the substrate to form a pattern portion, the electroless plating reaction is activated by using palladium ions (Pd ²⁺ ) as zero-valent metal (Pd ⁰ ). can do.

  For the activation treatment, it is necessary to select an appropriate method depending on the type of catalyst, and examples thereof include application of an acid, heating, and application of a reducing agent. A preferable reducing agent for palladium ions is a boron-based compound. Specifically, sodium borohydride, trimethylamine borane, dimethylamine borane (DMAB), and the like are preferable. As a reduction method, an activation treatment can be performed by immersing a substrate on which a pattern portion is formed in a reducing agent solution.

[Electroless plating process]
The electroless plating process according to the present invention will be described.

  In the present invention, the electroless plating process is performed by immersing the substrate on which the pattern portion is formed in an electroless plating solution (bath).

  The electroless plating solution mainly contains 1) metal ions, 2) complexing agent for electroless plating solution, and 3) reducing agent. Examples of the metal formed by electroless plating include gold, silver, copper, palladium, nickel, and alloys thereof, and copper, nickel, and alloys thereof are preferable from the viewpoint of adhesion and conductivity. Also as a metal ion used for an electroless plating bath, a metal ion corresponding to the metal is contained. The complexing agent and reducing agent for the electroless plating solution are also selected to be suitable for metal ions. Examples of complexing agents for electroless plating solutions include ethylenediaminetetraacetic acid (hereinafter abbreviated as EDTA), Rochelle salt, D-mannitol, D-sorbitol, dulcitol, iminodiacetic acid, trans-1,2-cyclohexane. Examples thereof include diaminetetraacetic acid, and EDTA is preferable. Examples of the reducing agent include formaldehyde, potassium tetrahydroborate, dimethylamine borane, glyoxylic acid and sodium hypophosphite, and formaldehyde is preferred.

  In the electroless plating treatment step, the metal formation speed and film thickness can be controlled by controlling the temperature, pH, immersion time, and metal ion concentration of the plating bath.

[Electroplating process]
In the metal pattern manufacturing method of the present invention, for the purpose of increasing the metal film thickness, an electroless plating process may be performed after the electroless plating process.

  In the electroplating process, after the electroless plating process, the metal pattern formed by the electroless plating process can be used as an electrode, and further electroplating can be performed. As a result, a metal pattern having an arbitrary thickness can be easily laminated on the metal pattern based on the metal pattern having excellent adhesion to the substrate. By adding an electroplating treatment step, the metal film can be formed to a thickness according to the purpose, so that the metal pattern of the present invention can be applied to various applications requiring high conductivity. became.

  As a method of electroplating treatment applicable to the present invention, a conventionally known method can be used. In addition, examples of the metal used in the electroplating process include copper, chromium, lead, nickel, gold, silver, tin, and zinc. From the viewpoint of conductivity, copper, gold, and silver are preferable, and copper is more preferable. preferable.

  About the film thickness of the electrically conductive film obtained by an electroplating process, it changes according to a use, and it can control by adjusting the metal concentration contained in a plating bath, immersion time, or current density. . In addition, from the viewpoint of conductivity, the film thickness when used for general electric wiring or the like is preferably 0.3 μm or more, and more preferably 3 μm or more.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

<Production of metal pattern>
[Production of Metal Pattern 1]
[Preparation of catalyst precursor ink]
An aqueous solution containing 2.0% palladium chloride having a mass ratio of palladium chloride to concentrated hydrochloric acid of 4: 1 was prepared. It was confirmed that palladium chloride was dissolved in this aqueous solution. Using this palladium chloride aqueous solution, the palladium chloride aqueous solution is 0.2%, the complexing agent is 2-aminopyridine 0.2%, the water-soluble organic solvent is 30% ethylene glycol, 10% glycerin, pure A catalyst precursor ink was prepared using water as a residue. Next, the pH of the catalyst precursor ink was adjusted to 14.0 using sodium hydroxide. As a result of visually observing the appearance of the prepared catalyst precursor ink, it was confirmed that palladium chloride was completely dissolved. The molar ratio (Pd: Ch) of palladium chloride (Pd) to 2-aminopyridine (Ch) in the catalyst precursor ink is 1: 1.9.

[Formation of metal pattern]
(Pattern formation process)
An ink jet head KM256Aq water system head (manufactured by Konica Minolta IJ Co., Ltd.) is attached to an ink jet head evaluation apparatus EB100 (manufactured by Konica Minolta IJ Co., Ltd.) attached to a transport system option XY100 (manufactured by Konica Minolta IJ Co., Ltd.), and the catalyst prepared above. The precursor ink can be discharged. A polyimide sheet with a thickness of 75 μm is attached to the stage as a non-ink-absorbing resin substrate, the catalyst precursor ink is discharged, and 10 fine line patterns and 1 pixel (wiring width 100 μm, wiring distance 100 μm, wiring length 30 mm) Pattern portions having different widths of 1 dot line) to 3 pixels (3 dot line) were formed.

(Washing process)
The pattern portion of the catalyst precursor formed was immersed in the following cleaning liquid 1 at 25 ° C. for 30 minutes for cleaning.

<Preparation of cleaning liquid 1>
As a positive metal ion compound, potassium chloride was dissolved in pure water at a concentration of 2.5 mol / L, and this was designated as cleaning solution 1. It was 0.4 g / L as a result of measuring the solubility in 25 degreeC according to the above-mentioned method using the prepared washing | cleaning liquid 1 and the pattern part of the said catalyst precursor formed.

(Activation process)
After carrying out the above-mentioned washing treatment and drying the pattern portion forming substrate at 80 ° C. for 5 minutes, the substrate was immersed in the following activation liquid containing a boron-based reducing agent to carry out activation treatment.

<Preparation of activation liquid>
Each of the following compounds was added and dissolved in pure water, and then finished up to 1000 ml with pure water to prepare an activation solution.

Alcup MRD2-A (Uemura Kogyo Co., Ltd.) 18ml
Alcup MRD2-C (manufactured by Uemura Kogyo Co., Ltd.) 60ml
922 ml of pure water
(Electroless plating process)
Using the following electroless copper plating solution at 50 ° C., the pattern portion forming substrate subjected to the activation treatment was subjected to electroless plating treatment to form a metal pattern 1 having a thickness of about 0.2 μm.

<Preparation of electroless copper plating solution>
Melplate CU-5100A (Meltex Co., Ltd.) 60ml
Melplate CU-5100B (Meltex Co., Ltd.) 55ml
Melplate CU-5100C (Meltex Co., Ltd.) 20ml
Melplate CU-5100M (Meltex Co., Ltd.) 40ml
825 ml of pure water
The prepared electroless copper plating solution has a copper concentration of 2.5%, a formalin concentration of 1.0%, and an ethylenediaminetetraacetic acid (EDTA) concentration of 2.5%. Moreover, pH was adjusted to 13.0 using sodium hydroxide.

[Production of metal patterns 2 to 12]
In the production of the metal pattern 1, the cleaning liquid used in the cleaning step is replaced with the cleaning liquid 1. The cleaning liquid having the structure shown in Table 1 (positive metal ion compound type and addition amount, temperature of the cleaning liquid) and solubility in the catalyst precursor Metal patterns 2 to 12 were formed in the same manner except that 2 to 12 were used.

<Evaluation of metal pattern>
Each of the formed metal patterns was subjected to the following evaluations.

[Evaluation of out-of-pattern precipitation: Evaluation of plating thickness resistance]
The pattern part having a width of 100 μm thus prepared was observed with an optical microscope, the width of 10 metal patterns was measured, the average value was obtained, the precipitation width outside the pattern was obtained according to the following formula, and the plating thickness resistance was determined according to the following criteria: Evaluated.

Precipitation width outside pattern (μm) = 10 average value (μm) −100 μm
A: The deposition width outside the pattern is less than 5.0 μm. ○: The deposition width outside the pattern is 5.0 μm or more and less than 10.0 μm. Δ: The deposition width outside the pattern is 10.0 μm or more, 20 Less than 0.0 μm ×: Precipitation width outside the pattern is 20.0 μm or more
The fine line patterns with different widths of the created 1 pixel (1 dot line) to 3 pixels (3 dot line) were observed with an optical microscope, and the plating property was evaluated according to the following criteria.

A: All the fine line patterns of 1 pixel to 3 pixels are finely plated. ○: A fine line pattern of 2 pixels and 3 pixels is plated, but a fine line pattern of 1 pixel is not plated. Δ: Plated in the fine line pattern of 3 pixels, but not plated in the fine line pattern of 1 pixel and 2 pixels. ×: Not plated in all of the fine line patterns. Table 1 shows.

  As is clear from the results shown in Table 1, the metal pattern created using the cleaning liquid defined in the present invention is less plated with respect to the comparative example, even if a fine line pattern having a different width is formed. It turns out that it is excellent in property.

Claims (6)

A pattern part is formed on a substrate using an ink containing an electroless plating catalyst precursor, and the catalyst precursor in the pattern part is converted into an electroless plating catalyst by an activation treatment. In the manufacturing method which forms a metal pattern by a plating process, it wash | cleans with the washing | cleaning liquid whose solubility of this catalyst precursor with respect to a washing | cleaning liquid is 0.5 g / L or less, and performs the said activation process, The metal pattern manufacturing method characterized by the above-mentioned. The method for producing a metal pattern according to claim 1, wherein the cleaning liquid contains positive metal ions, and the concentration of the positive metal ions is 2.5 mol / L or more. 3. The method for producing a metal pattern according to claim 2, wherein the positive metal ion is at least one selected from Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ and Ba ²⁺ . The method for producing a metal pattern according to any one of claims 1 to 3, wherein the catalyst precursor is a palladium metal complex. The metal pattern manufacturing method according to any one of claims 1 to 4, wherein the cleaning is performed with the cleaning liquid having a temperature of 10 ° C or higher and 50 ° C or lower. A metal pattern formed by using the metal pattern manufacturing method according to claim 1.