KR100863503B1 - Composition for dry-film photoresist - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry film resist composition used as an image forming material in the manufacture of a printed circuited board, wherein a polyalkylene glycol is added as an additive to a composition including a binder polymer, a photopolymerization monomer, and a photopolymerization initiator. Due to the addition of polyalkylene glycol, by effectively removing the bubbles generated during the stirring process during the dry film liquid preparation by suppressing the generation of pin holes or dents that can occur due to bubbles by implementing the uniformity of the coating It is effective in uniformity and stabilization of dry film resist, and at the same time, it is possible to reduce the amount of foaming of the developer and the stripping solution in the development and stripping process of the PCB manufacturing process.

Description

Composition for dry-film photoresist

The present invention relates to a dry film resist composition used as an image forming material when manufacturing a printed circuited board, and more particularly, to polyalkylene glycol as an additive in a composition including a binder polymer, a photopolymerization monomer, and a photopolymerization initiator. By adding to remove the air bubbles generated in the stirring process during the dry film liquid preparation to suppress pin holes or dents that can occur due to the air bubbles and to realize uniformity of the coating film quality uniformity of the dry film resist And it relates to a dry film resist composition which is effective in stabilization and at the same time can reduce the amount of foaming of the developer and the peeling solution in the development and peeling process in the process of manufacturing a printed circuit board.

The manufacturing process of the dry film is largely carried out in the process of crude liquid, mixing, coating, drying, winding, slitting. Specifically, the crude liquid and mixing process is a process of preparing a uniform coating liquid by preparing a drug for the dry film composition after stirring for a predetermined time, the coating is a process of applying a resist film of a constant thickness to the polyester film by a coater The drying process is a process of volatilizing the solvent contained in the crude liquid, and the winding process is a process of winding the dried coating film in the form of mill roll by laminating polyethylene or polyester protective film, and the slitting process is in the form of mill roll. Is to make the final product by cutting the dry film to the width and length that the consumer wants.

In the crude liquid and mixing process in the above process, in order to suppress the generation of bubbles generated during the operation of the stirring device, the stirring time and the stirring speed are controlled and left to stand for a certain time after stirring to remove the bubbles remaining in the crude liquid. However, due to the incomplete removal of the bubbles, pinholes or dents are generated on the dry film coating surface. Even if such defects occur, the inspection is difficult and difficult to detect, but it causes defects when used in the manufacturing process of the printed circuit board. come.

In order to reduce the defects caused by bubbles generated during the stirring process during the dry film manufacturing process, it is possible to leave the time left after stirring or to decrease the drying temperature and coating speed during coating.

However, in order to remove the air bubbles in the liquid solution as described above increases the stirring time and has a standing time over a certain time to bring down the production efficiency, there is a disadvantage that the above conditions cannot be made constant according to the viscosity of the liquid phase, organic solvent In order to suppress the generation of pinholes and dents during drying, down-regulation of the drying speed or drying temperature is required, thereby reducing productivity. In addition, even with this method, the pinholes and dents are not completely removed, and thus the productivity of the dry film is required.                         

On the other hand, the dry film undergoes a wet process when applied in a printed circuit board manufacturing plant, and is dissolved by an alkaline solution in a developing process of melting unexposed areas or a stripping process of removing a dry film. If bubbles are generated and bubbles are generated excessively, there are problems such as overflowing the chamber.

In order to solve this problem, an antifoaming agent which suppresses foam is used in an alkaline solution at a ratio of 0.1 to 3%.

However, the use of excessive antifoaming agent has a problem of increasing production cost and at the same time decreasing productivity. When excessive use of the antifoaming agent is combined with the components of dry film, scum that does not dissolve in water is generated, resulting in poor etching or poor plating. Caused by. Therefore, the need for dry film that does not require the use of an antifoaming agent is increased due to the small amount of foaming in the development and peeling process.

Therefore, the present inventors can improve the productivity by reducing the standing time after stirring while reducing surface unevenness such as pinholes or dents of the coated surface after coating and drying due to the bubble generation, which was a problem in the existing dry film manufacturing process, and later While seeking to develop a dry film composition that can reduce foaming in developing and peeling processes, which is a manufacturing process of a printed circuit board, the polyalkylene glycol was added as an additive to a general dry film composition, and then stirred during the preparation of dry film Effective removal of bubbles generated in the process can suppress the generation of pinholes or dents caused by bubbles, and it is possible to realize uniformity of coating, which is effective for uniformity and stabilization of quality of dry film resist and at the same time printing Phenomenon during the circuit board manufacturing process and during the peeling process And to know that it can reduce the amount of generation of bubble removing solution, thereby completing the present invention.

Therefore, an object of the present invention is to reduce the surface unevenness such as pinholes or dents of the coated surface after drying and foaming, which was a problem in the existing dry film manufacturing process, and to reduce productivity by reducing the standing time after stirring to remove bubbles The present invention provides a dry film resist composition which can improve the efficiency and at the same time reduce the generation of bubbles in the development and peeling process, which is a printed circuit board manufacturing process in the future.

The dry film resist composition of the present invention for achieving the above object comprises a binder polymer, a photopolymerization monomer, a photopolymerization initiator, a propylene glycol or a homopolymer of ethylene glycol or a copolymer thereof having a molecular weight of 100 to 1300 It is characterized in that it further comprises a polyalkylene glycol.

The present invention will be described in more detail as follows.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition of a dry film resist used in a printed circuit board manufacturing process. In general, a dry film resist further comprises polyalkylene glycol as an additive in a composition mainly comprising a binder polymer, a photopolymer, a photoinitiator, and other additives. It relates to the composition to contain.

The binder polymer is a methacryl-based copolymer as a methacryl-based monomer such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, ethylhexyl methacrylate, cyclohexyl It is selected from methacrylate, benzyl methacrylate, dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and glycidyl methacrylate, and these are used by copolymerizing them.

In addition, the methacrylic copolymers may be, if necessary, ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, anhydrides, semi-esterified polymers, or other polymers such as acrylics. It can be used by copolymerizing with amide, methacrylamide, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, alkylvinyl ether, of which acrylic acid and methacrylic acid are particularly preferred and exhibit excellent physical properties. In the case of the weak alkali developing photoresist resin, the amount of ethylenically unsaturated carboxylic acid is preferably used in an amount of 15 to 30% by weight (acid value of 100 to 200 mg / KOH / g).

In the dry film resist composition of the present invention, the photopolymerizable monomer may be a polyfunctional monomer or a monofunctional monomer as in the conventional dry film resist composition, and the monofunctional monomer is a methacrylate, an acrylate derivative, or a methacrylate. Monooxyethyl phosphate, methacrylate of phthalic acid derivatives, methylol methacrylamide, and the like. In the case of polyfunctional monomers, dimethacrylate and diacrylate derivatives, tri, tetra methacrylate and acrylate derivatives, etc. have.

The content of such a photopolymerization monomer is 10 to 80 parts by weight based on 100 parts by weight of the binder polymer solids. If the content is less than 10 parts by weight, the flexibility of the resist decreases, the development speed is slowed, and the content of the solution is greater than 80 parts by weight. Cold flow increases and peeling rate is slowed.

In the composition of the present invention, the photopolymerization initiator may be selected from benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin phenyl ether, benzyl diphenyl disulfide, benzyl dimethyl, as in a conventional dry film resist composition. Ketal, anthraquinone, naphthoquinone, benzophenone, pivalon ethyl ether, dichloro acetophenone, hexaaryl-imidazole dimer, tribromophenyl sulfone, tribromomethylphenyl sulfone and the like. The amount of such photoinitiator added is 1 to 20 parts by weight based on 100 parts by weight of the sum of the binder polymer and the photopolymerization monomer.

Other additives such as color-related preparations, photopolymerization inhibitors and plasticizers, of course.

Meanwhile, in the present invention, in order to minimize the generation of pinholes and dents in the manufacture of dry film resists, and to suppress the occurrence of bubbles in the later development and peeling process, it is characteristically based on alcohols and includes alkyl oxides such as ethylene oxide, Polyalkylene glycol formed by addition polymerization of propylene oxide and butylene oxide is added.

The polyalkylene glycol of the present invention preferably has a molecular weight of 100 to 1300 as a homopolymer of propylene glycol or ethylene glycol or a copolymer thereof.

It is preferable to use such polyalkylene glycol at 0.01 to 10% by weight in the resist composition. If the content exceeds 10% by weight, there is a problem in that the circuit implementation of the dry film is inferior.

The polyalkylene glycol added to the dry film resist composition effectively removes the bubbles generated during the stirring process, thereby increasing the efficiency of the stirring process and reducing the standing time after the preparation for removing the bubbles, and preventing the quality degradation caused by the bubbles. have.

In addition, by removing the organic solvent in the drying process, it can play a role as a leveling agent to drastically reduce the amount of pinholes or dents that can occur on the coating surface, thereby realizing the smoothness and uniform roughness of the coating surface, thereby contributing to the improvement of dry film quality. have.

In addition, the amount of defoamer used can be reduced by reducing the amount of foam that can occur in the development and peeling process of dry film during the manufacturing process of printed circuit boards, which can improve productivity, reduce costs, and contaminate water quality due to excessive use of defoamer. It has the advantage of preventing and reduces the occurrence of scum due to the combination of the antifoaming agent and the dry film.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Examples 1-6 and Comparative Examples 1-2

Next, a dry film photoresist having a photoresist composition shown in Table 1 was prepared, stirred for 1 hour, left for 30 minutes, and then coated on a PET film using a coating bar, and dried at 80 ° C. in an oven for 60 seconds. The number of dents or pinholes of 0.5 mm or more in the 20 cm x 20 cm plane of the surface was measured.

The measurement results are shown in Table 2 below. From this, it can be seen that the number of dents and pinholes decreases with the addition of polyalkylene glycol, and the surface properties are excellent depending on the amount added.

Example Comparative example One 2 3 4 5 6 One 2 Polymer binder Polymer Binder A 45 45 45 45 45 45 45 45 Photoinitiator Benzophenone 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 4,4 '-(bisdiethylamino) benzophenone 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Luco Crystal Violet 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Toluenesulfonic Acid Monohydrate 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Diamond Green GH 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Photopolymerizable monomer 9G 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 APG-400 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 BPE-500 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 menstruum Methyl ethyl ketone 13.0 13.0 13.0 13.0 13.0 13.0 13.0 13.0 Polyalkylene glycol Copolymer having molecular weight of 570-630, ethylene oxide: propylene oxide 1: 1 0.1 0.5 1.0 3.0 5 10 - 20 Luco Crystal Violet: 4,4,4-Tris (dimethyl amino) triphenyl methane, made by TCI Diamond Green G: Diamond Green, made by TCI 9G: polyethylene glycol # 400 dimethacrylate, manufactured by Miwon APG-400: Polypropylene glycol # 400 diacrylate, from micro yarn BPE-500: 2,2-bis [methacryloxypolyethoxy) phenyl] propane, from micro yarn

Example Comparative example One 2 3 4 5 6 One 2 Number of dents 25 10 9 7 5 5 30 3

Also, in order to compare the degree of foaming after development, 0.5 m 2 of a dry film of the above composition was dissolved in 300 ml developer (1 wt% aqueous solution of sodium carbonate), followed by air injection for 30 seconds, and then the heights of the bubbles were compared. Same as

From the results in Table 3, it can be seen that there is little foaming with increasing amount of polyalkylene glycol.

Example Comparative example One 2 3 4 5 6 One 2 Foam height (mm) 150 110 95 80 75 75 200 50

However, irrespective of the results of Tables 2 and 3, when the content of polyalkylene glycol is excessive (Comparative Example 2), there may be a problem that the circuit implementation of the dry film is inferior, so the maximum content thereof is 10% by weight. It is preferable.

Examples 7-11 and Comparative Examples 3-4

These examples are to determine the effect of the molecular weight of the polyalkylene glycol, after preparing a dry film photoresist having a photoresist composition shown in Table 4 and then stirred for 1 hour and left for 30 minutes and then coated using a coating bar After drying in an oven at 80 ° C. for 60 seconds, the number of dents or pinholes of 0.5 mm or more was measured in a 20 cm × 20 cm plane of the surface.

The measurement results are shown in Table 5, whereby the number of dents and pinholes decreases as the molecular weight of the polyalkylene glycol increases. However, when the molecular weight of the polyalkylene glycol is excessively large (1300 or more), it can be seen that the defective site increases, which is caused by the incompatibility with the existing dry film as the molecular weight increases, or the solubility of the solvent is inferior. It happens accordingly.

Example Comparative example 7 8 9 10 11 3 4 Polymer binder Polymer Binder A 45 45 45 45 45 45 45 Photoinitiator Benzophenone 3.0 3.0 3.0 3.0 3.0 3.0 3.0 4,4 '-(bisdiethylamino) benzophenone 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Luco Crystal Violet 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Toluenesulfonic Acid Monohydrate 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Diamond Green GH 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Photopolymerizable monomer 9G 10.5 10.5 10.5 10.5 10.5 10.5 10.5 APG-400 10.5 10.5 10.5 10.5 10.5 10.5 10.5 BPE-500 10.5 10.5 10.5 10.5 10.5 10.5 10.5 menstruum Methyl ethyl ketone 13.0 13.0 13.0 13.0 13.0 13.0 13.0 Polyalkylene glycol Ethylene oxide: Copolymer with propylene oxide 1: 1, 0.5 wt% of the total content 190-210 285-315 380-420 570-630 950-1050 50-100 1300-1500 Luco Crystal Violet: 4,4,4-Tris (dimethyl amino) triphenyl methane, manufactured by TCI Diamond Green G: Diamond Green, manufactured by TCI 9G: polyethylene glycol # 400 dimethacrylate, manufactured by MIGA APG-400: Polypropylene glycol # 400 diacrylate, microfiber product BPE-500: 2,2-bis [methacryloxypolyethoxy) phenyl] propane, microfiber product

Example Comparative example 7 8 9 10 11 3 4 Number of dents 20 15 12 10 8 25 32

Also, in order to compare the degree of foaming after development, 0.5 m 2 of a dry film of the composition was dissolved in a 300 ml developer (1 wt% aqueous solution of sodium carbonate), and then injected with air for 30 seconds, and then the heights of the bubbles were compared. Same as

Example Comparative example 7 8 9 10 11 3 4 Foam height (mm) 85 90 95 110 120 70 130

From the results in Table 6, it can be seen that the smaller the molecular weight of the polyalkylene glycol, the less foaming occurs. However, when the molecular weight is too small, the minimum value of the molecular weight is preferably 100 because there may be a problem of sublimation with the solvent in the drying step of the dry film manufacturing process.

This result is due to the fact that as the molecular weight of polyalkylene glycol increases, solubility becomes stronger, polymer having a large molecular weight is advantageous in the crude liquid, but polymer having a small molecular weight with high water solubility is advantageous in the alkaline aqueous solution during the developing process. .

Examples 12-16

In this embodiment, to determine the effect according to the ratio of the monomer constituting the polyalkylene glycol, after preparing a dry film photoresist having a photoresist composition shown in Table 7 and left for 30 minutes by stirring for 1 hour The coating was performed using a coating bar, and dried in an oven at 80 ° C. for 60 seconds, and the number of dents or pinholes of 0.5 mm or more was measured in a 20 cm × 20 cm plane. The measurement results are shown in the following Table 8, whereby it can be seen that the best surface properties when the monomer of the polyalkylene glycol is ethylene glycol: propylene glycol = 50: 50.

Example 12 13 14 15 16 Polymer binder Polymer Binder A 45 45 45 45 45 Photoinitiator Benzophenone 3.0 3.0 3.0 3.0 3.0 4,4 '-(bisdiethylamino) benzophenone 1.5 1.5 1.5 1.5 1.5 Luco Crystal Violet 3.0 3.0 3.0 3.0 3.0 Toluenesulfonic Acid Monohydrate 1.0 1.0 1.0 1.0 1.0 Diamond Green GH 1.0 1.0 1.0 1.0 1.0 Photopolymerizable monomer 9G 10.5 10.5 10.5 10.5 10.5 APG-400 10.5 10.5 10.5 10.5 10.5 BPE-500 10.5 10.5 10.5 10.5 10.5 menstruum Methyl ethyl ketone 13.0 13.0 13.0 13.0 13.0 Polyalkylene glycol Molecular weight 570 ~ 630, 0.5 wt% of total content Ethylene Glycol: Propylene Glycol 100: 0 80:20 50:50 20:80 0: 100

Example 12 13 14 15 16 Number of dents 17 15 10 14 15

Also, in order to compare the degree of foaming after development, 0.5 m 2 of a dry film of the composition was dissolved in 300 ml developer (1 wt% aqueous solution of sodium carbonate), followed by air injection for 30 seconds, and then the heights of the bubbles were compared. Same as

From the results in Table 9, it was found that when the monomer constituting the polyalkylene glycol is ethylene glycol: propylene glycol 50:50, there is little foaming.

Example 12 13 14 15 16 Foam height (mm) 115 120 95 105 100

As described in detail above, when a propylene glycol or ethylene glycol homopolymer and a copolymer thereof and polyalkylene glycol having a molecular weight of 100 to 1300 are further added to the conventional dry film resist composition according to the present invention, By effectively removing bubbles generated during the stirring process, the efficiency of the stirring process can be increased, and the standing time after preparation for removing bubbles can be reduced, and the deterioration of quality due to the bubbles can be prevented. It can play a role to reduce the amount of pinholes or dents that can occur on the coating surface, thereby realizing the smoothness and uniformity of the coating surface, which can contribute to the improvement of dry film quality. The amount of foam that can occur during film development and peeling It can reduce the amount of antifoaming agent, which can improve productivity, reduce cost, and prevent water pollution due to excessive use of antifoaming agent, and reduce scum caused by the combination of antifoaming agent and dry film. .

Claims (2)

In a dry film resist composition comprising a binder polymer, a photopolymerization monomer, a photopolymerization initiator and an additive, A dry film resist composition characterized by further comprising polyalkylene glycol having a molecular weight of 100 to 1300 as a homopolymer of propylene glycol or ethylene glycol or a copolymer thereof. The dry film resist composition of claim 1, wherein the polyalkylene glycol is contained in an amount of 0.01 to 10% by weight based on the total dry film composition.