JP2007023160A - Coating agent and metal mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new coating agent for metal mask, preventing adhesion and clogging and imparting sufficiently improved leaving property and life, even when the metal mask has fine openings distributed in a high density. <P>SOLUTION: The coating agent for forming a thin film on the surface of a metal mask formed of a metallic material and having openings with a predetermined pattern comprises a fluorine-containing phosphonic acid compound containing fluorine in a molecule and is composed so that the phosphonic acid of the fluorine-containing phosphonic acid compound forms a salt with the metal atom of the metal mask. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coating agent, and more specifically, a metal mask used as a masking means in printing or the like, that is, a coating agent useful for forming a thin film having ink repellency on the surface of a metal mask. About. The present invention also relates to a metal mask having on its surface a thin film made of such a coating agent.

  As is well known, in the manufacture of electronic devices and the like, it is generally performed to form a wiring pattern, an external connection terminal, etc. by printing a conductive material such as cream solder on the surface of a printed circuit board, for example. In order to selectively print a conductive material, a metal mask formed of a metal material and having openings in a predetermined pattern is widely used. The metal mask is made of a metal material such as stainless steel or nickel. From these thin plates of metal material, for example, a method of opening an opening having a desired pattern by etching, or by performing metal plating on a resist pattern in which the shape of the opening has been formed in advance and removing the resist, the opening metal A desired metal mask can be manufactured by a method of forming a plate (so-called electroforming method) or the like.

  By the way, when a conductive material that is normally used in a paste state is printed on the surface of a printed circuit board via a metal mask, the paste adheres to the sidewall of the opening of the metal mask or the opening is blocked. As a result, there arises a problem that printing is not performed according to a desired pattern. This kind of problem has been increasing in recent years because semiconductor mounting components have been downsized and the mounting density tends to increase, and the openings have become finer and higher in density accordingly. . In particular, if the opening of the metal mask is fine, the ability to remove the paste deteriorates and printing itself becomes difficult.

  In order to solve such a problem, for example, Patent Document 1 discloses that a chemisorption monomolecular film containing fluorine derived from a fluorine-based silane coupling agent is formed on the surface of a metal metal mask material having openings having a desired pattern. We have proposed a metal mask characterized by the fact that Patent Document 2 discloses a metal mask for printing in which a hole for wiring pattern is formed and applied on a screen by applying a printing paste made of a conductive material, and the entire surface of the metal mask is coated with a fluororesin. We have proposed a metal mask for printing that is characterized by the above. Further, Patent Document 3 discloses a printing metal formed by a predetermined process after a dry film is stuck on a metal substrate, a photographic original plate is adhered and exposed, and either a photosensitive or unexposed portion is dissolved and removed. In the mask, a metal mask for printing has been proposed in which nickel / PTFE plating is applied to other portions of the metal mask excluding the surface that is in close contact with the object to be printed. Furthermore, Patent Document 4 is characterized in that a silicone-modified fluorine-based resin is applied to the metal layer opening inner wall and the metal layer substrate side and cured to form a cured resin layer as the opening inner wall surface covering layer and the substrate surface covering layer. The metal mask for printing is proposed.

Japanese Patent Laid-Open No. 5-220922 (Claims) JP-A-8-290686 (Claims) Japanese Patent Laid-Open No. 10-250032 (Claims) JP 2002-192850 A (Claims)

  As described above, in the conventional technology, in order to improve the printability by preventing the adhesion or clogging of the printing paste or the like to the metal mask, a fluorine-based silane coupling agent is chemically adsorbed on the surface of the metal mask. Surface modification methods such as coating a fluororesin, applying nickel / PTFE plating, and coating a silicone-modified fluororesin have been proposed. However, as described above, in recent years, semiconductor mounting components and the like have been downsized and the mounting density has been increased, so that these surface modification methods cannot provide sufficient effects. In particular, in these surface modification methods, there is a limit to the decrease in surface tension at the opening, and the ability to remove printing paste or the like cannot be sufficiently improved. Further, the surface modification film formed by the conventional method has a drawback that the metal mask has a short life because it has poor bonding strength to the metal mask. Furthermore, the surface modification film formed by the method described in Patent Documents 1 to 3 described above has a thickness of several microns and has a drawback that the shape of the opening is changed.

  Accordingly, the object of the present invention is to prevent the adhesion and clogging of printing paste and the like to the metal mask even when the metal mask has a fine opening and is distributed at a high density. It is an object of the present invention to provide a novel metal mask coating agent that can provide a long life.

  The object of the present invention is also used as a masking means when printing a printing paste or the like in a predetermined pattern, and when the openings are fine and distributed at high density. Is to provide a metal mask which has an excellent ability to remove printing paste and has a long usable life.

  These and other objects of the present invention will be readily understood from the following detailed description.

  As a result of diligent research to achieve the above-described object, the present inventor has made a -Si-O-Metal-bond to a metal atom of a metal mask as in the case of the above-described fluorine-based silane coupling agent, for example. Thus, the present invention has been completed by obtaining the knowledge that a new form of formation of a salt with a metal atom and phosphonic acid is effective without adopting a method for fixing a chemisorbed monomolecular film through the method.

  In one aspect, the present invention is a coating agent used for forming a thin film on the surface of a metal mask formed of a metal material and having openings in a predetermined pattern, and contains fluorine in the molecule. The coating agent is characterized by comprising a fluorine-containing phosphonic acid compound, and the phosphonic acid of the fluorine-containing phosphonic acid compound can be bonded to a metal atom of the metal mask to form a salt.

  In another aspect of the present invention, there is provided a metal mask formed of a metal material and having an opening in a predetermined pattern, wherein at least the surface of the opening (that is, the surface of the side wall) The metal mask is characterized by comprising a fluorine-based phosphonate thin film formed from the coating agent.

  When the metal mask coating agent of the present invention is used, as will be understood from the following detailed description, in a metal mask formed of a metal material, the openings are fine and each opening has a high density. Even if it is formed by, it is possible to prevent adhesion and clogging of printing paste etc. to the metal mask, and thus it is possible to realize a sufficiently improved detachability, and furthermore, the fluorine-based phosphon formed Since the acid thin film is firmly bonded to the metal mask and does not easily wear out or peel off, the usable life of the metal mask can be greatly extended compared to the conventional product.

  Therefore, according to the present invention, when printing paste or the like is printed as a predetermined pattern, it is used as a masking means, and the openings are fine and distributed at a high density. Even in such a case, it is possible to provide a metal mask that is excellent in the ability to remove printing paste and the like and has a long usable life.

  The metal mask of the present invention can be advantageously used in the production of electronic devices and the like, for example, when a conductive material such as cream solder is printed on the surface of a printed circuit board to form a wiring pattern, an external connection terminal, or the like. In addition, for example, in general printing technology such as screen printing, the masking means is used for printing various printing materials to form a printed matter, or for depositing a resist material in a desired pattern in a photolithography process. Can be used advantageously.

  The metal mask coating agent and the metal mask according to the present invention can be advantageously implemented in various forms. Hereinafter, although the coating agent and metal mask of this invention are each demonstrated about the preferable form, it should be understood that this invention is not limited to these forms.

  The coating agent according to the invention is specifically designed for metal masks. That is, the coating agent of the present invention is used to form a thin film on the surface of a metal mask formed of a metal material and having openings in a predetermined pattern. Here, the metal mask is not particularly limited in its configuration and application, and is generally used as a masking means in the manufacture of electronic devices, the field of printing technology, and the field of photolithography processes. Therefore, it can be arbitrarily produced from various metal materials. Examples of suitable metal materials include iron, stainless steel, nickel, and chromium. These metal materials may be used in the form of an alloy if necessary. A metal mask can usually be manufactured from these metal materials using conventional techniques such as etching and electroforming.

  The metal mask has openings opened in a predetermined pattern in order to transfer a printing paste or the like to an underlying substrate or the like. The pattern of the opening can be arbitrarily formed according to a transfer pattern such as a printing paste. What is important here is that the metal mask of the present invention may have openings having a relatively large size and a relatively sparse distribution density, which are conventionally common, but is fine and / or Or when it has an opening part with high distribution density, it means that the effect of this invention can be exhibited. When the coating agent of the present invention is coated on the opening of the metal mask, the coating agent can be firmly bonded to the side wall of the opening even when applied to a fine and high-density opening. As such, it can exhibit superior effects compared to conventional surface modifiers such as fluorine-based silane coupling agents, thus significantly improving the ability to remove printing pastes and greatly extending the useful life. be able to.

  In the practice of the present invention, the printing paste used is not particularly limited, and includes any printing material that can be used for printing with the metal mask of the present invention. Suitable printing pastes include, for example, solder pastes such as cream solder, printing ink pastes used for screen printing, resist resists used for resist processes, and the like. These pastes are not particularly limited numerically, but preferably have sufficient viscosity to pass through the openings.

  The coating agent of the present invention comprises a fluorine-containing phosphonic acid compound containing fluorine in the molecule. In addition, this fluorine-containing phosphonic acid compound can form a salt by bonding the phosphonic acid to a metal atom of the metal mask when the coating agent of the present invention is applied to a predetermined part of the metal mask as a surface modifier. is there. Since the surface covered with the salt of the fluorinated phosphonic acid compound has a very low surface energy, it can exhibit excellent paste repellency and releasability.

  In the practice of the present invention, various fluorine-containing phosphonic acid compounds can be used as a coating agent. The molecular weight of the fluorine-containing phosphonic acid compound is usually about 400 to 5000, and preferably about 1000 to 3000. Suitable fluorine-containing phosphonic acid compounds include perfluoropolyether phosphonic acids, such as compounds (I), (II) and (III) represented by the following formula:

(In the above formula, n is an integer of about 3 to 30, preferably an integer of about 3 to 15, more preferably an integer of about 3 to 10). It is a compound of this. Such a fluorine-containing phosphonic acid compound can be synthesized by various methods.

  Another preferred fluorine-containing phosphonic acid compound is a compound having an amide bond, for example, compounds (IV) and (V) represented by the following formula:

(In the above formula,
R _f is a monovalent or divalent perfluoropolyether group,
y is 1 or 2,
X may be the same or different and each represents hydrogen, a cycloalkyl group, an alkali metal, ammonium, an ammonium substituted with an alkyl group or a cycloalkyl group, or a 5- to 7-membered complex having a positively charged nitrogen atom. Represents a cyclic group, usually hydrogen,
R ¹ represents hydrogen or an alkyl group, and R ² represents a divalent group selected from the group consisting of an alkylene group, an arylene group, a heteroalkylene group, and a combination thereof, and at least one selected from the group consisting of It is a kind of compound. The molecular weight of these compounds is usually about 400 to 5000, preferably about 1000 to 3000.

  More specifically, the fluorine-containing phosphonic acid compound represented by the above formula (IV) is, for example, a compound represented by the following formula.

  In the above formula, n is an average value of 0 to 50, 1 to 50, 3 to 30, 3 to 15, or 3 to 10. It should be noted that derivatives of such compounds need to be acids. Such a fluorine-containing phosphonic acid compound can be synthesized by various methods.

  When the above-described fluorine-containing phosphonic acid compound is applied to a metal mask as a coating agent, it can be applied by various methods in consideration of the type, amount of use, characteristics and the like of the fluorine-containing phosphonic acid compound. In general, a method in which these fluorine-containing phosphonic acid compounds are applied to a metal mask in the form of a solution, dried, and reacted can be used. A method of depositing in a desired pattern may be used. When applied in the form of a solution, the fluorine-containing phosphonic acid compound can be used by dissolving or diluting in a solvent such as hydrofluoroether or perfluoropolyether. Of course, if necessary, a spray method, a dipping method or the like may be used instead of the coating method.

  The coating formed on the metal mask from the above-mentioned fluorine-containing phosphonic acid compound, that is, the fluorine-based phosphonate thin film is a variety of pastes that are filled in the metal mask openings in the subsequent steps, such as solder paste, printing It has repellent properties that repel ink pastes and resin pastes.

  In addition, the fluorine-based phosphonate thin film can have various film thicknesses. According to the present invention, a thin film of a fluorinated phosphonate can be formed very thin, and such a thin film does not adversely affect the function and effect of the present invention.

  The present invention resides in a metal mask using the coating agent in addition to the above-described coating agent for the metal mask. That is, the metal mask of the present invention is a metal mask formed of a metal material and having openings in a predetermined pattern, and at least the fluorine-based phosphones formed of the coating agent of the present invention on the surface of the openings of the metal mask. A thin film of acid salt is provided.

  The metal mask of the present invention can be advantageously implemented in various forms. FIG. 1 is a sectional view showing a preferred embodiment of the metal mask of the present invention. The metal mask 10 includes a base material 1 and openings 2 formed in a desired pattern at an arbitrary position thereof. Although the opening 2 has a vertical inner wall in the illustrated example, the opening 2 may be inclined or chamfered if necessary in order to improve the removal property and workability of the paste. The metal mask 10 can be formed from, for example, stainless steel, nickel, or the like by commonly used techniques such as etching, laser drilling, or electroforming. For example, when producing a metal mask from stainless steel, first, a stainless steel plate having a desired thickness is prepared, and then a dry film resist is applied to both the front and back surfaces. Next, in the dry film resist, the region corresponding to the opening of the metal mask is selectively dissolved and removed. Thereafter, the exposed stainless steel plate is dissolved and removed with an appropriate etchant using a dry film resist as a masking means. Finally, when the dry film resist is removed, a metal mask 10 having an opening 2 as shown in FIG. 1 is obtained.

  Here, the shape and dimensions will be described. Although the metal mask 10 can be used in an arbitrary shape, it is generally rectangular. Moreover, although the thickness of the metal mask 10 can be changed in a wide range depending on factors such as the material and usage of the metal mask, it is usually about 500 μm or less, and generally about 200 to 300 μm. It is a range. Similarly, the opening 2 of the metal mask 10 can also be formed in an arbitrary shape according to the use of the metal mask, that is, factors such as the profile of the wiring pattern to be formed, the printing pattern, and the like. Moreover, even if this opening part 2 is fine, it does not exert a bad influence on the effect of this invention. For example, even if the opening 2 of the metal mask 10 is finely formed and the minimum dimension thereof is on the order of several μm, the effect of the present invention will not be adversely affected.

  The metal mask 10 of the present invention includes a fluorine-based phosphonate thin film 3 formed from the coating agent of the present invention at least on the surface of the opening 2 of the metal mask. As shown in the figure, the fluorine-based phosphonate thin film 3 is preferably disposed on the inner periphery (side wall) of the opening 2 and in the vicinity thereof. In addition to the inner periphery of the opening 2, the fluorine-based phosphonate thin film is preferably formed on the back surface 4 of the metal mask 10. Further, if necessary, a fluorine-based phosphonate thin film may be formed on the surface 5 of the metal mask 10.

  As described above, the fluorine-based phosphonate thin film can be formed from a coating agent comprising a fluorine-containing phosphonic acid compound containing fluorine in the molecule. Details of the fluorine-containing phosphonic acid compound that can be used are as described above. In addition, the method for forming the fluorine-based phosphonate thin film can be arbitrarily changed depending on the properties of the fluorine-containing phosphonic acid compound used, but as described briefly above, the fluorine-containing phosphonic acid compound The method of apply | coating to a metal mask in the form of a solution, drying, and making it react can be used.

  More specifically, the method of forming the fluorine-based phosphonate thin film is suitable for coating by diluting the selected fluorine-containing phosphonic acid compound with an appropriate solvent such as hydrofluoroether or polyfluoropolyether. A paste having a proper viscosity or a solution as required is obtained. Next, the obtained paste or solution is coated on a metal mask in which openings are already formed according to a conventional method. Examples of the coating method include spray coating, spin coating, dip coating, and the like. After coating is complete, the solvent is removed by air drying followed by baking in an oven. The baking temperature is usually about 100 to 150 ° C. for about 30 minutes. By this baking, the bond strength of the coating to the metal mask can be increased.

  In the metal mask 10 of the present invention, the fluorine-based phosphonate thin film 3 formed on the inner wall surface of the opening 2 can have various film thicknesses. Preferably, the fluorinated phosphonate thin film 3 of the present invention can have a thickness of about 100 nm or less, more preferably about 5 nm or less, and most preferably Can have a film thickness of about 3 nm or less. As a result of the discovery of the present inventors, a thin film of a fluorinated phosphonate can be formed as very thin as could not be considered by conventional methods. There is no adverse effect on the operational effects. Therefore, the film thickness of the fluorine-based phosphonate particularly suitable for the practice of the present invention is in the range of about 1 to 100 nm, and the film thickness particularly suitable is in the range of about 1 to 5 nm.

  The metal mask according to the present invention can be advantageously used in various applications. For example, in the manufacture of electronic devices and the like, the metal mask of the present invention can be used to form a solder pattern such as cream solder on a substrate such as a printed wiring board. The metal mask of the present invention can also be used for forming a print pattern on a substrate by screen printing or the like. Furthermore, the metal mask of the present invention can be used to form a resin pattern on a substrate. For example, the metal mask of the present invention can be used to form a resist pattern by a photolithography process or the like.

  FIG. 2 is a cross-sectional view sequentially illustrating a method of printing a solder paste on a printed board using the metal mask of the present invention.

  First, as shown in FIG. 2A, the metal mask 10 of the present invention is placed on the printed circuit board 11. The metal mask 10 has an opening 2 at a position corresponding to a land portion (not shown) of the printed circuit board 11 according to a desired print pattern, and the opening 2 is formed on the inner wall surface of the metal mask 10. It has a thin film 3 of fluorinated phosphonate derived from the coating agent of the invention. The thin film 3 is not only firmly bonded to the base material of the metal mask 10 but also has a property of repelling a paste of cream solder that fills the opening in a subsequent process.

  Next, as shown in FIG. 2B, a cream solder paste 12 is prepared and filled in the opening 2. In the illustrated example, a squeegee 13 is used to assist this filling operation. Various cream solders can be used in the practice of the present invention. Examples of the solder composition include Sn—Pb, Sn—Ag, Sn—Cu, and Sn—Ag—Cu.

  After the filling of the cream solder 12 is completed, the metal mask 10 is removed from the printed board 11. As shown in FIG. 2C, a solder pattern 12 is formed on the land portion of the printed board 11. The solder pattern 12 is in a state where the shape of the opening 2 is reproduced as it is. Particularly in the case of the present invention, since the thin film 3 of the metal mask 10 is excellent in releasability, part of the cream solder is not separated while being attached to the metal mask 10. Thus, no printing failure occurs, so that no soldering failure occurs after reflow of cream solder.

  Subsequently, the present invention will be described with reference to examples thereof. Needless to say, the present invention is not limited to these examples.

Example 1
In this example, a fluorine-containing phosphonic acid represented by the following formula was prepared.

A 250 ml round bottom flask equipped with an overhead stirrer and a water condenser is prepared and 10 g (0.041 mol) diethyl (4-aminobenzyl) phosphonate, 4.15 g (0.041 mol) triethylamine and 100 ml Methyl t-butyl ether was combined under nitrogen. To this mixture, 41.8 g (0.041 mol) of C ₃ F ₇ [CF (CF ₃ ) CF ₂ O] nCF (CF ₃ ) COF (Mw = 1017) was added dropwise over about 1.5 hours. After stirring at ambient temperature for 16 hours, the resulting solution was diluted with additional methyl t-butyl ether, washed with about 5% aqueous sodium bicarbonate and then once with 2N hydrochloric acid. After drying over magnesium sulfate, the solvent was removed on a rotary evaporator.

  The product obtained was dissolved in diethyl ether and an additional 17.6 g (0.115 mol) of bromotrimethylsilane was added in one portion. The solution was stirred at ambient temperature for 24 hours and an additional amount (10 g) of silane was added. After several hours, anhydrous methanol was added to decompose unreacted silane and silyl ether. After removing the solvent from the resulting solution, the residue was treated twice with anhydrous methanol in the same manner as described above. After reducing the volume with a rotary evaporator, the final methanol solution was poured into water and the solid product was collected by filtration and air dried. It was confirmed by analysis that the desired fluorine-containing phosphonic acid was obtained.

Example 2
In this example, the metal mask of the example of the present invention was produced using the fluorine-containing phosphonic acid prepared in Example 1 as a coating agent. Moreover, the commercially available fluorine-type silane coupling agent represented by the metal mask of the comparative example which does not use a coating agent, and following Formula:

A metal mask of a control example using was prepared together.

Fabrication of metal mask (comparative example):
A plurality of rectangular openings (0.2 mm × 0.4 mm) were opened by etching in a 300 μm-thick stainless steel film to produce a metal mask of a comparative example.

Production of metal mask (example of the present invention):
After opening a plurality of rectangular openings (0.2 mm × 0.4 mm) in a 300 μm-thick stainless steel film by etching, the fluorine-containing phosphonic acid prepared in Example 1 was added to the openings of the obtained metal mask. Coating was performed as follows. The fluorine-containing phosphonic acid was diluted to 5% by weight in isopropyl alcohol, and the solid was dissolved by shaking. The resulting solution was filtered and diluted with methyl perfluorobutyl ether to obtain a 0.1 wt% coating solution. The cleaned metal mask was immersed in the coating solution for 20 hours and air-dried.

Production of metal mask (control example):
After opening a plurality of rectangular openings (0.2 mm × 0.4 mm) in a 300 μm-thick stainless steel film by etching, the obtained metal mask was placed in a hydrofluoroether solution of the above-mentioned fluorine-based silane coupling agent. Immerse over time and air dry.

[Evaluation of solder paste removal]
After the metal mask produced as described above was superimposed on a commercially available printed wiring board, cream solder (paste) was printed on the printed wiring board from above each metal mask. The cream solder used in this example was Sn—Ag—Cu alloy solder (product number “M705”, manufactured by Senju Metal Industry Co., Ltd.) having a melting temperature of 217 to 220 ° C. After the cream solder was completely filled in the opening of the metal mask using a squeegee, the metal mask was removed to form a solder print.

  The transferred solder pattern of the solder printed matter formed on each printed wiring board was observed with a laser microscope. When a metal mask (comparative example) is used, the pattern that should have been a rectangular shape becomes an elliptical transfer solder pattern with rounded corners, and part of the solder remains detached from the metal mask. It showed that. It was also found that the solder itself had a noticeable graininess and poor paste removal.

  On the other hand, when a metal mask (control example) was used, a transfer solder pattern in which the rectangular opening of the metal mask was well reproduced was obtained. It has been found that there is no problem with the solder particles themselves, the paste can be easily removed, and the printing characteristics are excellent. Furthermore, when a metal mask (invention example) was used, results comparable to the control example were obtained. That is, a transfer solder pattern in which the rectangular opening of the metal mask was well reproduced was obtained. It has been found that there is no problem with the solder particles themselves, the paste can be easily removed, and the printing characteristics are excellent.

Example 3
In this example, a metal mask (control example) and a metal mask (invention example) were prepared according to the technique described in Example 2. In addition, in this example, in addition to the 300-micrometer-thick stainless steel film, the same thickness iron film, nickel film, and chromium film were used as a base material of a metal mask.

  In order to evaluate the durability of each metal mask, (1) the water contact angle after wiping the surface of the metal mask coating with wiping paper containing acetone, and (2) the surface of the metal mask coating is oily The ease of wiping the drawn lines written with a pen (using wiping paper) was measured by the following method. The reason for using acetone in this example is that the solder paste is generally prepared by dispersing solder fine particles in a viscous organic compound such as flux. This is because a simple organic solvent is often used, and this is simulated in this example.

(1) Measurement of pure water contact angle on the surface Using the contact angle meter and contact tangle meter (CA-A type) manufactured by Kyowa Kagaku Co., Ltd. as the pure water contact angle of the coating surface of each metal mask, Measured by simple procedure.
1. Wipe the acetone-impregnated wiping paper with 5 reciprocations (5 reciprocations: none, 1, 2, or 3).
2. Installation of a syringe containing pure water.
3. Contact angle measurement by the droplet method.
In this example, each metal mask was measured three times, and the average value was obtained. The measurement results described in Tables 1 and 2 below were obtained.

(2) Measurement of ease of wiping drawn lines Writing black drawing using oil-based markers (trade name “Mackey”, manufactured by Zebra).
2. Wipe the acetone-impregnated wiping paper with 5 reciprocations (5 reciprocations: none, 1, 2, or 3).
3. Visual observation of the wiping surface with wiping paper.
The presence or absence of black drawing was visually observed on the wiping surface of each metal mask. In this example, the case where the black drawing was wiped off was evaluated as “good”, the case where the black drawing wiping trace remained was “good”, and the case where the black drawing was not wiped was evaluated as “impossible”. The evaluation results described in Tables 1 and 2 below were obtained.

  As can be understood from the measurement results shown in Table 1 and Table 2, the fluorine-containing phosphonic acid of the present invention not only improves the durability against wiping cleaning with acetone, but also forms a wide range of metal masks. The ability to wipe off the marker dirt, that is, the ability to more easily remove the solder paste or the like can be imparted to the substrate.

It is sectional drawing which showed one preferable form of the metal mask by this invention. It is sectional drawing which showed the method of printing a solder paste on a printed circuit board using the metal mask of this invention later on.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Opening 3 Fluorine phosphonate thin film 4 Fluorine phosphonate thin film 5 Fluorine phosphonate thin film 10 Metal mask 11 Printed wiring board 12 Solder paste 13 Squeegee

Claims (9)

  A coating agent used for forming a thin film on the surface of a metal mask formed of a metal material and having openings in a predetermined pattern, comprising a fluorine-containing phosphonic acid compound containing fluorine in the molecule, and A coating agent, wherein a phosphonic acid of a fluorine-containing phosphonic acid compound forms a salt with a metal atom of the metal mask. The fluorine-containing phosphonic acid compound is represented by the following formulas (I), (II) and (III):

The coating agent according to claim 1, wherein the coating agent is at least one compound selected from the group consisting of (wherein n is an integer of 3 to 30). The fluorine-containing phosphonic acid compounds are represented by the following formulas (IV) and (V):

(In the above formula,
R _f is a monovalent or divalent perfluoropolyether group,
y is 1 or 2,
X may be the same or different and each represents hydrogen, a cycloalkyl group, an alkali metal, ammonium, an ammonium substituted with an alkyl group or a cycloalkyl group, or a 5- to 7-membered complex having a positively charged nitrogen atom. Represents a cyclic group,
R ¹ represents hydrogen or an alkyl group, and R ² represents a divalent group selected from the group consisting of an alkylene group, an arylene group, a heteroalkylene group, and a combination thereof, and at least one selected from the group consisting of The coating agent according to claim 1, wherein the coating agent is a kind of compound.   A metal mask formed of a metal material and having openings in a predetermined pattern, wherein the fluorine mask is formed at least on the surface of the openings from the coating agent according to claim 1. A metal mask characterized by comprising a thin film of acid salt.   The metal mask according to claim 4, wherein the fluorine-based phosphonate thin film has a thickness of 1 to 100 nm.   6. The metal mask according to claim 4, wherein the fluorine-based phosphonate thin film has a thickness of 1 to 5 nm.   The metal mask according to any one of claims 4 to 6, wherein the metal mask is used for forming a solder pattern on a substrate.   The metal mask according to any one of claims 4 to 6, wherein the metal mask is used to form a printed pattern on a substrate.   The metal mask according to any one of claims 4 to 6, which is used for forming a resin pattern on a substrate.

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