KR101404761B1 - Photosensitization epoxy resin compositions for forming via hole, and method for forming via hole on PCB using the same - Google Patents

Abstract

The present invention relates to a photosensitive epoxy resin composition for forming a via hole containing a photoacid generator and an epoxy resin, and a method of forming a via hole in a printed circuit board using the same. According to the present invention, a photosensitive epoxy resin composition in which a piperidinium salt is introduced as a photoacid generator can be used to form via holes through exposure and development processes. The method of forming a via hole using the photosensitive epoxy resin composition for forming a via hole according to the present invention is advantageous in that the process is simple and the cost can be reduced as compared with the existing technology. In addition, since the method of forming a via hole according to the present invention can maintain the physical properties of the interlayer insulating film, it is possible to solve the disadvantage that inherent properties of epoxy are inhibited in the epoxy resin modification process of the existing technology. In addition, the present invention has an effect of providing a photosensitive epoxy resin composition for forming a via hole in a portion where heat resistance, adhesiveness, chemical resistance, toughness, electrical insulation and the like are required to maintain characteristics inherent to the epoxy resin.

Description

[0001] The present invention relates to a photosensitive epoxy resin composition for forming a via hole and a method for forming a via hole in a printed circuit board using the same,

The present invention relates to a photosensitive epoxy resin composition for forming a via hole and a method for forming a via hole in a printed circuit board using the same. More specifically, the present invention relates to a photosensitive epoxy resin composition for forming a via hole comprising a piperidinium salt and an epoxy resin, And a method of forming a via hole in a printed circuit board using the same.

In the case of a method of forming a via hole of a multilayer printed wiring board interlayer insulating film by a method of forming a via hole in a printed circuit board, a conventional technique is a method of forming a cured film by forming an epoxy resin composition with an interlayer insulating film of a multilayer printed wiring board, ) And a drill tip process. However, in the above method, since the number of via holes in the PCB exceeds several tens to hundreds of thousands per panel, there is a problem that a lot of equipment and time are invested.

A method of forming a via hole through photolithography is also used. This technique is a technique in which an epoxy resin is denatured and a photoinitiator is introduced in order to enable formation of a fine pattern through an exposure process, and a prior art of this field is disclosed in Korean Patent Publication No. 2010-0081316.

However, when a conventional technique is used, it is possible to form a fine pattern through an exposure process. However, when applied to an epoxy resin, the inherent characteristics of the resin are impaired in the course of denaturing the epoxy resin. And physical properties (heat resistance, adhesiveness, thermal expansion coefficient, etc.) of PCB are lowered due to the use of acrylic resin capable of photopolymerization and development while forming holes at the same time and by development. There was a problem.

The present inventors have made intensive efforts to develop a method capable of forming a fine via hole while maintaining physical properties of an interlayer insulating film at a low cost under the above technical background. As a result, it has been found that a photosensitive epoxy resin for forming a via hole containing a photoacid generator and an epoxy resin A method of forming a via hole of a printed circuit board using a composition has been developed.

It is an object of the present invention to provide a photosensitive epoxy resin composition for forming a via hole containing a piperidinium salt and an epoxy resin as a photoacid generator and a process for producing the epoxy resin composition for a via hole, And a method of forming a via hole in a printed circuit board including an exposure and a development step.

According to one aspect of the present invention, there is provided a photosensitive epoxy resin composition for forming a via hole comprising a piperidinium salt and an epoxy resin as a photoacid generator.

According to an embodiment of the photosensitive epoxy resin composition for forming a via hole according to the present invention, the photosensitive epoxy resin composition for forming a via hole may further include a photosensitizer, a thermosetting agent, and an inorganic filler.

According to one embodiment of the photosensitive epoxy resin composition for forming a via hole according to the present invention, the piperidinium salt may be 1,1-dibenzylpiperidinium hexafluoroantimonate, 1,1-dibenzylpiperidinium para Toluene sulfonate, 1,1-dibenzylpiperidinium 2,4,6-triisopropylbenzene sulfonate, 1,1-dibenzylpiperidinium chemosulfuronate, 1,1-dibenzylpiperidinium hepta Decafluorooctanesulfonate, 1,1-dibenzylpiperidinium 9,10-diethoxyanthracene-2-sulfonate, 1,1-dibenzylpiperidinium hexafluorophosphate, 1,1-dibenzyl Piperidinium trifluoromethanesulfonate, and 1,1-dibenzylpiperidinium nonafluoro-1-butanesulfonate.

According to one embodiment of the photosensitive epoxy resin composition for forming a via hole according to the present invention, the content of the photoacid generator may be 0.1 to 10 parts by weight based on the epoxy resin.

According to one embodiment of the photosensitive epoxy resin composition for forming a via hole according to the present invention, the epoxy resin is selected from the group consisting of bisphenol A type, bisphenol F type, phenol-novolac, cresol- It may be more than one selected.

According to another aspect of the present invention, there is provided a method of preparing a photosensitive epoxy resin composition, comprising: preparing a photosensitive epoxy resin composition for forming a via hole; Laminating the epoxy resin composition on a printed circuit board; Raising a patterned film or glass mask on the substrate and exposing it to UV light; Developing the exposed substrate; There is provided a method for forming a via hole in a printed circuit board including a step of drying the developed substrate, and then heat-treating the printed substrate.

According to an embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the step of laminating the epoxy resin composition on a substrate may be performed by directly coating the epoxy resin composition on the substrate.

According to one embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the step of laminating the epoxy resin composition on a substrate comprises coating the epoxy resin composition on a film and drying the film to prepare a dry film, And transferring the dry film to a substrate.

According to an embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the UV wavelength of the exposure step may be 350 to 450 nm.

According to one embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the step of developing the exposed substrate includes a method of spraying a developer onto a substrate, a method of shaking the substrate after immersing the substrate in a developing solution, And a method in which the substrate is immersed in a developing solution to perform ultrasonic treatment.

According to an embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the heat-treatment in the post-curing step may be performed at 120 to 200 ° C for 10 to 90 minutes.

According to the present invention, a photosensitive epoxy resin composition in which a piperidinium salt is introduced as a photoacid generator can be used to form via holes through exposure and development processes. The method of forming a via hole using the photosensitive epoxy resin composition for forming a via hole according to the present invention is advantageous in that the process is simple and the cost can be reduced as compared with the existing technology. In addition, since the method of forming a via hole according to the present invention can maintain the physical properties of the interlayer insulating film, it is possible to solve the disadvantage that inherent properties of epoxy are inhibited in the epoxy resin denaturation process of the prior art. In addition, the present invention has an effect of providing a photosensitive epoxy resin composition for forming a via hole which can be used in a portion where heat resistance, adhesion, chemical resistance, toughness, electrical insulation and the like are required to maintain characteristics inherent to the epoxy resin.

1 shows a method of forming a via hole in a printed circuit board according to the present invention.
2 is a microscopic view of a via hole manufactured according to the test example of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

According to an aspect of the present invention, there is provided a photosensitive epoxy resin composition for forming a via hole comprising a photoacid generator and an epoxy resin.

The photoacid generator is a compound capable of generating an acid by light and is not particularly limited as long as it is a compound of this nature. Generally, onium salts, latent sulfonic acids, halomethyl-s-triazine, metallocenes, chlorinated acetophenones, or benzoinphenyl ethers can be used as the photoacid generators. In the present invention, the piperidinium salts are used as photoacid generators Can be used.

The piperidinium salt is not particularly limited as long as it is a dibenzylpiperidinium salt. In one embodiment of the present invention, 1,1-dibenzylpiperidinium hexafluoroantimonate, 1,1-dibenzyl Pivalidinium para-toluenesulfonate, 1,1-dibenzylpiperidinium 2,4,6-triisopropylbenzenesulfonate, 1,1-dibenzylpiperidinium chemosulfuronate, 1,1-dibenzyl 1,1-dibenzylpiperidinium 9,10-diethoxyanthracene-2-sulfonate, 1,1-dibenzylpiperidinium hexafluorophosphate, 1, 1-dibenzylpiperidinium trifluoromethanesulfonate, and 1,1-dibenzylpiperidinium nonafluoro-1-butanesulfonate.

The content of the photoacid generator may be 0.1 to 10 parts by weight based on the epoxy resin.

If the content of the photoacid generator is less than 0.1 parts by weight with respect to the epoxy resin, not only the necessary exposure amount becomes too large but also the coating film is melted at the time of development and a fine pattern is not formed, and the content of the photo- If it exceeds the weight part, the unit cost of the composition is increased, and it is difficult to control the formation of a desired fine pattern.

The epoxy resin is not particularly limited, but according to one embodiment of the present invention, the epoxy resin may be selected from the group consisting of bisphenol A type, bisphenol F type, phenol-novolak, cresol-novolac, It may be more than one selected.

Epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin may be used as the epoxy resin such as methyl ethyl ketone (MEK), demethylformamide (DMF), methylcellosolve (MCS), carbitol acetate, PGME, toluene, xylene, NMP, 2-methoxyethanol, etc. may be mixed and dissolved as a solvent. In addition, since a cured product having high heat resistance can be obtained and the thermal stability of the substrate formed can be improved, it is preferable to use the phenol-novolak or cresol-novolak epoxy resin as the novolak type epoxy resin.

On the other hand, the rubber-modified epoxy resin can be used by mixing DGEBA (diglycidyl ether of bisphenol A) and CTBN (Carboxy terminated butadiene acrylonitrile copolymer). The epoxy resins may be selected from the group consisting of methyl ethyl ketone (MEK), demethylformamide (DMF), methylcellosolve (MCS), carbitol acetate, carbitol, PGMEA, PGME, toluene, xylene, NMP, 2-methoxyethanol And the like.

According to an embodiment of the photosensitive epoxy resin composition for forming a via hole according to the present invention, the photosensitive epoxy resin composition for forming a via hole may further include a photosensitizer, a thermosetting agent, and an inorganic filler.

The photosensitizer may be added to improve the sensitivity to the exposure wavelength of the epoxy resin composition containing the photoacid generator. According to an embodiment of the present invention, the photosensitizer may be a thioxanthone-based compound. According to one embodiment of the present invention, it is preferable to use at least one selected from the group consisting of isopropylthioxanthone, 2-chlorothioxanthone, and diethylthioxanthone as the thioxanthone-based compound . The above thioxanthone-based compounds allow the photoacid generator to easily reach the excited state to make the acid more easily generated. According to an embodiment of the present invention, it is preferable that the content of the photosensitizer is 200 parts by weight or less with respect to the photoacid generator. This is because if the content of the photosensitizer exceeds 200 parts by weight, the effect of reducing the exposure dose becomes insignificant.

In the above, the thermosetting agent may be added to improve the thermal stability of the insulating material. In the present invention, the heat curing agent may be at least one selected from the group consisting of acid anhydride, and latent heat curing agent.

Examples of the acid anhydride include methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl hymic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, There may be mentioned trialkyl tetrahydrophthalic anhydride, hexa hydrophthalic anhydride, methyl cyclohexane dicarboxylic anhydride, phthalic anhydride, trimethylic anhydride, Pyromethylic anhydride, benzophenonetracarboxylic anhydride, or ethylene glycol bis (trimethylic) anhydride may be used.

In one embodiment of the present invention, at least one selected from the group consisting of a pyridinium salt compound and a pyridinium salt compound may be used as the latent heat curing agent.

In the present invention, the thermosetting agent can be used within a conventional equivalent ratio to which an epoxy thermosetting agent is applied to the mixing equivalent of the epoxy resin to be used.

In addition, the inorganic filler may be added to improve physical properties such as heat resistance and strength of the epoxy resin composition. According to one embodiment of the present invention, the inorganic filler may be at least one member selected from the group consisting of talc, silica, barium sulfate, and titanium oxide . According to an embodiment of the present invention, the diameter of the inorganic filler may be 10 탆 or less. This is because if the diameter exceeds 10 탆, there is a problem that the via hole is not formed well.

In addition, pigments, dyes and the like may be mixed according to the composition of the photosensitive epoxy resin composition for forming a via hole according to the present invention or the application object thereof.

According to another aspect of the present invention, there is provided a method of preparing a photosensitive epoxy resin composition, comprising: preparing a photosensitive epoxy resin composition for forming a via hole; Laminating the epoxy resin composition on a printed circuit board; Raising a patterned film or glass mask on the substrate and exposing it to UV light; Developing the exposed substrate; There is provided a method for forming a via hole in a printed circuit board including a step of drying the developed substrate, and then heat-treating the printed substrate. 2 shows a method of forming a via hole in a printed circuit board according to the present invention.

According to an embodiment of the present invention, the step of laminating the epoxy resin composition on a printed circuit board may include a method of directly coating the epoxy resin composition on a substrate, or a method of coating a film on a film and drying the film, And transferring the film to the substrate.

In addition, according to an embodiment of the present invention, the UV wavelength of the exposure step is not particularly limited, but is generally preferably 350 to 450 nm.

In the developing step, an organic solvent mixed with a mixed organic solvent or water is used as a developing solution, and at least one surfactant may be included. According to an embodiment of the present invention, the step of developing the exposed substrate includes a method of spraying the developer onto the substrate, a method of shaking the substrate after immersing the substrate in the developer, and a method of ultrasonication by immersing the substrate in the developer Or by a method selected from the group consisting of

The method for forming a via hole in a printed circuit board according to the present invention includes the step of drying and then curing the developed substrate by heat treatment. Removing the solvent remaining on the developed substrate through drying, and post-curing at a high temperature to increase the curing density of the epoxy resin.

According to an embodiment of the method for forming a via hole in a printed circuit board according to the present invention, the heat-treatment in the post-curing step may be performed at 120 to 200 ° C for 10 to 90 minutes. When the heat treatment temperature is lower than 120 ° C, the curing rate is lowered. When the heat treatment temperature is higher than 200 ° C, the manufacturing cost is increased.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

Example

A via hole  Preparation of photosensitive epoxy resin composition for forming

A photosensitive epoxy resin composition was prepared according to the following Examples 1 to 4 and Comparative Examples 1 and 2 in the composition shown in Table 1 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 YD-128 30g 30g 30g 30g 30g - YDCN-500-80P 50g 50g 50g 50g 50g 30g Epoxy acrylate resin - - - - - 70g Methyl cellosolve 20g 20g 20g 20g 20g - 1,1-dibenzylpiperidinium hexafluorophosphate 4g 4g - 1,1-dibenzylpiperidinium trifluoromethanesulfonate 4g - 1,1-dibenzylpiperidinium nonafluoro-1-butanesulfonate 4g - MS-7 - - - - - 3g Talc 20g 20g 20g 20g 20g 20g MeTHPA 40g 40g 40g - 60g - SP-600 - - - 2g - - 2MZ - - - - 2g -

Example  One

30 g of YD-128 (Kuko Chemical), an epoxy resin, and 50 g of YDCN-500-80P (Kukdo Chemical) were dissolved in 15 g of methylcellosolve as a solvent and heated to 80 ° C for 3 hours to dissolve. 20 g of talc was added to the dissolved epoxy solution, and the mixture was milled three times with a three-roll mill to disperse the talc completely. Milled epoxy resin mixture and 5 g of methyl cellosolve dissolved in 4 g of 1,1-dibenzylpiperidinium hexafluorophosphate as a photoacid generator were added and mixed. Then, MeTHPA (40 g) was added and stirred at room temperature for 1 hour And mixed.

Example  2

4 g of 1,1-dibenzylpiperidinium trifluoromethanesulfonate as a photoacid generator and 5 g of a latent heat curing agent SP-600 (manufactured by SM Co., Ltd.) were added to 5 g of the milled epoxy resin mixture prepared as in Example 1 and 5 g of methyl cellosolve ) Was added, and the mixture was stirred at room temperature for 1 hour.

Example  3

4 g of 1,1-dibenzylpiperidinium nonafluoro-1-butanesulfonate as a photoacid generator and 5 g of SP-600 as a latent heat curing agent were added to 5 g of the milled epoxy resin mixture prepared in Example 1 and methylcellosolve (SM seed) was added, and the mixture was stirred at room temperature for 1 hour and mixed.

Example  4

4 g of 1,1-dibenzylpiperidinium hexafluorophosphate as a photoacid generator and 2 g of SP-600 (SM Co.) as a latent heat curing agent were added to 5 g of the milled epoxy resin mixture prepared in Example 1 and methylcellosolve Was added, and the mixture was stirred at room temperature for 1 hour.

Comparative Example  One

A solution obtained by dissolving 60 g of MeTHPA and 2 g of a curing accelerator 2MZ (Sigma Aldrich) in 5 g of the milled epoxy resin mixture prepared in Example 1 and 5 g of methyl cellosolve was added and stirred at room temperature for 1 hour.

Comparative Example  2

30 g of YDCN-500-80P (Kukdo Chemical) was added to 70 g of epoxy acrylate resin (SM Co.), and the mixture was heated to 40 캜 and stirred for 5 hours to dissolve. Then, 3 g of a photoinitiator MS- The mixture was stirred at room temperature for 3 hours to dissolve completely to obtain a transparent mixed resin. 20 g of talc was added to the mixed resin, and the mixture was milled three times with a three-roll mill to completely disperse the talc.

Experimental Example  : Example  1 to 4 and Comparative Example  Comparison of properties after curing of compositions according to 1 and 2

The photosensitive epoxy resin compositions prepared according to Examples 1 to 4 and Comparative Examples 1 and 2 were directly coated on a CCL (Copper Clad Laminate) substrate as a coating base and dried to remove the solvent. The CCL substrate coated with the solvent-removed coating film was exposed to light with an exposure machine, developed into a developer composed of methyl cellosolve, and dried. The dried CCL substrate was cured at 180 캜 for 40 minutes.

Measurement of thermal expansion coefficient

Tg (glass transition temperature) and CTE (thermal expansion coefficient) of each of the cured compositions were measured using a TMA Q 400 thermal analyzer manufactured by TA. Tg was measured at the second scanning, and the temperature was measured at a temperature of 25 to 250 DEG C at a heating temperature of 10 DEG C / min.

Adhesion measurement

In order to measure the adhesion, the cured film was cut into 100 pieces by Cross-Cut (10x10), and after the 3M tape was affixed, the number of pieces to be peeled off was checked. .

Hole open  Measure

In order to measure hole open, after the above exposure and development process, the formation of a via hole was confirmed by a microscope.

The experimental results are shown in Table 2 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Tg  (° C) 175 173 169 175 170 105 CTE (? ₁ ) 40 48 45 41 43 55 Adhesiveness 100/100 100/100 100/100 100/100 100/100 100/100 Hole open
(100/60) 占 퐉 ○ ○ ○ ○ X ○

Referring to Table 2, the epoxy resin composition of the present invention has the following advantages as compared with the comparative example using a photoacid generator and a curing accelerator or photoinitiator.

First, the glass transition temperature (Tg value) is high and the heat resistance is excellent. In the case of Comparative Example 1, there was no significant difference from that in Example 1 at 170 ° C, but in Comparative Example 2, it was found that the temperature dropped sharply to 105 ° C. Therefore, it can be seen that the results of Examples 1 to 4 do not show the average glass transition temperature of 173 ° C. Therefore, when the photoacid generator according to the present invention is used, the heat resistance is superior to the case where the photoacid generator is not used and the reliability is high.

Second, when the photoacid generator according to the present invention is used, it is confirmed that the CTE is low and the dimensional stability is excellent due to less heat deformation. In Examples 1 to 4, the average CTE value is 43.5, which means that the variation is not large, but the comparative example shows a large increase up to 55.

Third, the via holes formed in the printed circuit board according to the method of forming a via hole of the present invention exhibit a high degree of uniformity. In the above table, it can be seen that the hole opening does not occur in the case of the comparative example 1, so that the reliability in the case of using the photo acid generator according to the present invention is much higher. As shown in FIG. 2, the via hole formed according to the present invention can be confirmed to be formed very uniformly.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (11)

As the photoacid generator, 1,1-dibenzylpiperidinium hexafluoroantimonate, 1,1-dibenzylpiperidinium para-toluenesulfonate, 1,1-dibenzylpiperidinium 2,4,6-tri Isopropylbenzene sulfonate, 1,1-dibenzylpiperidinium chemosulfuronate, 1,1-dibenzylpiperidinium heptadecafluorooctanesulfonate, 1,1-dibenzylpiperidinium 9,10 -Diethoxyanthracene-2-sulfonate, 1,1-dibenzylpiperidinium hexafluorophosphate, 1,1-dibenzylpiperidinium trifluoromethanesulfonate and 1,1-dibenzylpiperidinium nona Fluoro-1-butanesulfonate, and an epoxy resin.
The method according to claim 1,
Wherein the photosensitive epoxy resin composition for forming a via hole further comprises a photosensitizer, a thermosetting agent, and an inorganic filler.
The method according to claim 1,
Wherein the content of the photoacid generator is 0.1 to 10 parts by weight based on the weight of the epoxy resin.
The method according to claim 1,
Wherein the epoxy resin is at least one selected from the group consisting of bisphenol A type, bisphenol F type, phenol-novolak, cresol-novolak, and rubber modified epoxy resin. delete delete delete delete delete delete delete

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