KR101044114B1 - Resin composition for printed circuit board and printed circuit board using the same - Google Patents

Abstract

The present invention relates to a resin composition for a printed circuit board and a printed circuit board using the same, triglycidyl isocianurate (TGIC) resin, DGEBA (diglycidyl ether of bisphenol A) epoxy resin, cresol novolac epoxy A composite epoxy resin comprising a resin, a phosphorous epoxy resin and a rubber-modified epoxy resin; Bisphenol A-based curing agent; A curing accelerator; A resin composition for a printed circuit board containing an inorganic filler.

Printed Circuit Board, Resin Composition, Triglycidyl Isocyanurate, Composite Epoxy Resin

Description

Resin composition for printed circuit board and printed circuit board using same {Resin composition for printed circuit board and printed circuit board using the same}

The present invention relates to a resin composition for a printed circuit board and a printed circuit board using the same.

The demand for thin boards with fine circuits is increasing along with the high functionality, high capacity, and miniaturization and thinning of mobile phones. In addition, high reliability is required to maintain electrical characteristics in thermal and physical shocks. Therefore, instead of the existing method of fabricating copper foil and insulating layer, for example, prepreg by using vacuum-press, the insulating film was laminated using a build-up method, and then fined by plating. There is a need for an introduction of a method for implementing a circuit.

In order to introduce a new method, it is required to develop a new concept of insulating material that can replace the existing insulating material. The existing build-up insulation material has a peel strength of about 0.5 to 0.8 kN / m depending on the desmear condition, and the build-up insulation material stably exhibiting a value of 1.0 kN / m or more is currently It is not commercialized. However, according to the trend of high functionality, high capacity, and slimness of mobile phones, when pre-preg or Resin Coated Copper (RCC) is used, insulation materials for build-up are used in the outer layer of the mobile phone substrate to realize the thinning and fine pattern of the mobile phone substrate. In order to secure a drop reliability equal to or higher than that, it is necessary to develop a build-up insulating material capable of exhibiting a peel strength value of 1.0 kN / m or more.

The manufacturing process of the existing printed circuit board is made of a prepreg-type insulating material containing glass fiber and copper foil using a copper foil laminated plate using a V-press, and then subjected to a circuit such as plating, exposure, development, peeling, and etching. In this way, as the copper foil and the prepreg are stacked in a V-press, it is difficult to implement a microcircuit due to a certain Cu thickness, and window exposure and an additional process are added to form micro vias after lamination. There are problems such as an increase in manufacturing procurement time and an increase in process cost.

On the other hand, if the insulating material of the build-up method is used, since only the insulating film is formed into a vacuum laminate and then a circuit is formed by plating method, there is no base Cu, so it is easy to implement a fine circuit, and the number of processes can be reduced, thereby increasing productivity. have. Accordingly, in order to introduce a new construction method, the development of a new concept of insulating material that can replace the existing insulating material is urgently required.

The present invention is to solve the above-mentioned problems of the prior art, one aspect of the present invention is to introduce a toughness (triglycidyl isocianurate (TGIC)) resin by introducing an epoxy resin composition instead of a conventional curing agent (toughness) It is to provide a resin composition for a printed circuit board with increased) and a printed circuit board using the same.

Another aspect of the present invention is to provide a resin composition for a printed circuit board and a printed circuit board using the same, which ensures excellent reliability characteristics and is free from defects such as delamination and cracks in reliability tests such as high temperature thermal shock. .

According to a first preferred aspect of the invention,

1-8 wt% triglycidyl isocianurate (TGIC) resin, 1-20 wt% DGEBA (diglycidyl ether of bisphenol A) epoxy resin, 30-70 wt% cresol novolac epoxy resin Composite epoxy resins comprising from 20 to 30% by weight of phosphorus-based epoxy resins and from 1 to 20% by weight of rubber-modified epoxy resins;

Bisphenol A curing agents;

Curing accelerators; And

Inorganic fillers;

There is provided a resin composition for a printed circuit board comprising a.

In the resin composition, the bisphenol A-based curing agent may be preferably included in an amount of 0.5 to 1.5 equivalents based on the total mixed equivalents of the epoxy groups of the composite epoxy resin.

In addition, 0.1 to 1 part by weight of a curing accelerator and 10 to 30 parts by weight of an inorganic filler may be included based on 100 parts by weight of the composite epoxy resin.

Here, the average epoxy resin equivalents of (i) TGIC resin, (ii) DGEBA-based epoxy resin, (iii) cresol novolac epoxy resin, (iv) phosphorus-based epoxy resin and (v) rubber modified epoxy resin are respectively (i ) 85 to 125, (ii) 200 to 600, (iii) 100 to 300, (iv) 400 to 800 and (v) 200 to 400.

It is preferable that the said hardening | curing agent has a softening point of 100-140 degreeC, and a hydroxyl group equivalent is 100-150.

The curing agent may also have a ratio of the epoxy group of the composite epoxy resin and the phenolic hydroxyl group of the curing agent is 1: 0.7 to 1: 1.3.

The curing accelerator is preferably an imidazole compound, more preferably 2-ethyl-4-methyl imidazole, 1- (2-cyanoethyl) -2-alkyl imidazole, 2-phenyl imidazole and At least one compound selected from the group consisting of mixtures thereof.

The inorganic filler may be surface treated with a silane coupling agent.

The inorganic filler may also have any one or two or more shapes of plate, cubic, colloidal and needle shaped.

At this time, it is preferable that the average particle diameter of the said inorganic filler is 0.1-10 micrometers.

According to a second preferred aspect of the present invention, there is provided a printed circuit board manufactured using the resin composition described above.

The resin composition for a printed circuit board and the printed circuit board using the same according to the present invention have excellent reliability characteristics, and thus may prevent defects such as delamination or cracks at a high temperature thermal shock test.

Accordingly, it is possible to introduce a new method of forming an insulating layer by vacuum lamination of an insulating film made of a composite epoxy resin from a conventional method of laminating a copper foil and a prepreg.

In addition, the peel strength is improved as compared with the conventionally developed build-up insulation material, thereby ensuring a drop reliability equal to or higher than when using a prepreg or an RCC.

In addition, it is possible to further improve the toughness of the epoxy resin composition as the insulating layer to ensure excellent reliability in high temperature thermal shock test.

Hereinafter, the present invention will be described in more detail.

The present invention relates to an epoxy resin composition for a printed circuit board comprising an epoxy resin having a TGIC structure, and particularly exhibits excellent reliability characteristics by preventing delamination or cracking in tests such as HAST (Highly Accelerated Stress Test) and high temperature thermal shock. At the same time, it is possible to implement excellent peel strength, and provides a flame retardant composition having excellent properties such as thermal stability and mechanical strength.

In addition, the present invention provides a printed circuit board applied as an outer layer structural material of a multilayer wiring board using an existing substrate manufacturing process using such an epoxy resin composition. In particular, while exhibiting flame retardancy and excellent peel strength, the toughness of the final insulating material is improved, which is characterized by excellent thermal shock reliability.

The resin composition for a printed circuit board according to the preferred embodiment of the present invention includes a composite epoxy resin, a curing agent, a curing accelerator, and an inorganic filler.

The composite epoxy resin used in the present invention is triglycidyl isocianurate (TGIC) resin, DGEBA (diglycidyl ether of bisphenol A) epoxy resin, cresol novolac epoxy resin, phosphorus epoxy resin and rubber modified epoxy Resin.

The TGIC resin is a triazine-based polyfunctional epoxy resin, and is mainly used as a curing agent of a polyester resin in the field of powder coating, and is represented by the following Chemical Formula 1.

Since the TGIC has three epoxide groups capable of forming a three-dimensional network structure, as shown in Formula 1, the TGIC lysate has various functional groups in the presence of a catalyst or the like, like other epoxides, For example, it easily reacts with primary, secondary amines, carboxylic acids, carboxylic acid anhydrides, phenols, alcohols and the like. Moreover, the hardened | cured material has favorable weather resistance and excellent heat resistance, and is excellent in electrical and mechanical performance.

The TGIC resin is included in an amount of 1 to 8% by weight of the composite epoxy resin. When the content is less than 1% by weight, it is difficult to secure high temperature thermal shock reliability, and when the content is more than 8% by weight, the high temperature thermal shock reliability is deteriorated due to a property that is vulnerable to moisture absorption of the TGIC resin.

It is preferable that the average epoxy resin equivalent of the said TGIC resin is 85-125. If the average epoxy resin equivalent of the TCIG resin is less than 85, it is difficult to impart desired physical properties to the structure to the composite epoxy resin, and if it exceeds 125, the melting point is too high and difficult to control.

In the DGEBA-based epoxy resin used in the present invention, the epoxy functional group and the secondary alcoholic hydroxyl group present in the resin are reactive, and thus curing reaction by, for example, the epoxy functional group and / or the hydroxyl group may occur. Since the DGEBA-based epoxy resin is difficult to freely rotate the benzene nucleus of bisphenol A, the DGEBA-based epoxy resin has excellent high temperature characteristics, has an ether group in the molecule, and has chemical and plastic properties. In addition, since hydrophilic hydroxyl groups and hydrophobic hydrocarbon groups are regularly arranged, adhesiveness is excellent, and electrical properties such as electrical insulation and dielectric constant after curing are excellent. The above-described properties may vary depending on the degree of polymerization.

The DGEBA-based epoxy resin is included in an amount of 1 to 20% by weight of the composite epoxy resin. If the content is less than 1% by weight, desired physical properties cannot be obtained, and if the content is more than 20% by weight, cracks due to brittleness are not preferable.

It is preferable that the average epoxy resin equivalent of the said DGEBA type epoxy resin is 200-600. If the average epoxy resin equivalent is less than 200, it is difficult to exhibit the desired physical properties, and if it exceeds 600, it is not preferable because it is difficult to dissolve in the solvent and the melting point is too high to control.

The cresol novolac epoxy resin used in the present invention can obtain a cured product having many functional groups and excellent heat resistance, chemical resistance, and electrical properties, and improve thermal stability and mechanical strength of the formed substrate.

The cresol novolac epoxy resin is included in the content of 30 to 70% by weight of the composite epoxy resin, the average epoxy resin equivalent is preferably 100 to 300.

When the content of the cresol novolac epoxy resin is less than 30% by weight, it is not possible to obtain inherent heat resistance properties, and when it exceeds 70% by weight, the electrical mechanical properties are lowered, which is not preferable.

In addition, if the average epoxy resin equivalent weight of the cresol novolac epoxy resin is less than 100, it is difficult to exhibit desired physical properties, and if it exceeds 300, it is difficult to dissolve in a solvent and the melting point is too high to control.

Phosphorus-based epoxy resin used in the present invention is excellent in flame retardancy and self-extinguishing. In the present invention, in order to impart flame retardancy to a printed circuit board, a phosphorous epoxy resin is added, and halogen-free eco-friendly flame retardant substrates can be obtained.

The phosphorus epoxy resin is included in 20 to 30% by weight of the composite epoxy resin. If the content of the phosphorus-based epoxy resin is less than 20% by weight, it is difficult to impart desired flame retardancy, and if it exceeds 30% by weight, the electrical mechanical properties are lowered, which is not preferable.

In addition, the phosphorus epoxy resin is preferably an average epoxy resin equivalent of 400 to 800. If the phosphorus-based epoxy resin equivalent is less than 400, it is difficult to impart flame retardant properties to the composite epoxy resin, and if it exceeds 800, it is not preferable because it is difficult to dissolve in the solvent and the melting point is too high to control.

The rubber-modified epoxy resin used in the present invention provides toughness to the epoxy cured product to improve impact resistance.

The rubber modified epoxy resin is included in 1 to 20% by weight of the composite epoxy resin. When the content of the rubber-modified epoxy resin is less than 1% by weight, it is difficult to expect improvement in toughness, and when the content of the rubber-modified epoxy resin is more than 20% by weight, the elasticity of the cured product may be increased to reduce dimensional stability.

The rubber-modified epoxy resin preferably has an average epoxy resin equivalent of 200 to 400. If the rubber-modified epoxy resin equivalent is less than 200, it is difficult to improve brittleness, and if it exceeds 400, the melting point becomes too high and difficult to control, which is not preferable.

The composite epoxy resin can be dissolved in a mixed solvent such as 2-methoxy ethanol, methyl ethyl ketone (MEK), dimethyl formamide (DMF), or the like.

The curing agent used in the present invention can improve the adhesive strength of the final cured product to the bisphenol A novolac type.

It is preferable that the usage-amount of the said hardening | curing agent is 0.5-1.5 equivalent with respect to the total mixing equivalent of the epoxy group of the said composite epoxy resin.

The curing agent has a softening point of 100 to 140 ℃, the hydroxyl equivalent of 100 to 150 is most preferred in terms of the desired physical properties. The larger the equivalent of the hydroxyl group means that the bisphenol A-based curing agent has a higher molecular weight, thereby increasing the softening point. In general, the curing agent used in the present invention has a bisphenol structure between two hydroxyl groups by a certain repeating unit, and when the equivalent weight is large, as the molecular weight of the curing agent connecting the epoxy chain and the chain is increased, the structure of the final cured product is reduced. As such, it is advisable to use a curing agent having an appropriate level of equivalent as described above.

On the other hand, the ratio of the epoxy group of the composite epoxy resin and the phenolic hydroxyl group of the curing agent is preferably 1: 0.7 to 1: 1.3 in terms of the desired physical properties and reactivity.

The curing accelerator used in the present invention may be an imidazole compound, and according to a preferred embodiment, 2-ethyl-4-methyl imidazole, 1- (2-cyanoethyl) -2-alkyl imidazole, 2-phenyl At least one imidazole compound selected from the group consisting of imidazole and mixtures thereof.

The curing accelerator is preferably mixed in an amount of 0.1 to 1 parts by weight based on 100 parts by weight of the composite epoxy resin. When the content of the curing accelerator is less than 0.1 parts by weight, the curing rate is significantly lowered and the curing reaction is not completely made, uncuring may occur, and if more than 1 part by weight, fast curing may occur.

Inorganic fillers used in the present invention are added to reinforce poor physical properties such as mechanical strength and adhesive properties of the cured composite epoxy resin, and include, for example, graphite, carbon black, silica, CaCO ₃ and clay. One or more may be selected from the group. Preferably, the inorganic filler may be surface treated with a silane coupling agent to improve dispersing properties, and may have irregular shapes, for example, shapes and sizes, such as plate-like, cubic, colloidal and needle-like. It is preferable to exhibit high peel strength because it is advantageous in forming surface roughness by desorption of filler and enhancing mechanical anchoring effect with wiring layer during roughening plating.

It is preferable that the inorganic filler has an average particle diameter of 0.1 to 10 μm in terms of the desired property expression, and is preferably used in an amount of 10 to 30 parts by weight based on 100 parts by weight of the composite epoxy resin. If the amount of the inorganic filler is less than 10 parts by weight, it is difficult to expect the improvement of the desired mechanical properties, and if it exceeds 30 parts by weight, the peel strength may be lowered, which is not preferable.

In addition, by adding an additional flame retardant aid, it is possible to lower the content of the relatively high phosphorus flame-retardant epoxy resin price. As the flame retardant aid, a compound such as Al ₂ O ₃ containing phosphorus may be used, but is not particularly limited thereto.

When the substrate is manufactured using the resin composition of the present invention as described above, it exhibits excellent reliability characteristics, for example, defects such as delamination or cracking in tests such as HAST (Highly Accelerated Stress Test) and high temperature thermal shock. You can prevent it.

In addition, the peel strength is excellent, and the thermal stability and mechanical strength, such as excellent properties, for example, the outermost layer of the mobile phone substrate was implemented by the conventional pressing method while switching from the prepreg type to the build-up type Peel strength should be implemented after the desmear and plating process using the buildup method, which is very suitable for application as an interlayer insulating layer for buildup.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited thereto.

≪ Example 1 >

1) A mixed solvent of 316.54 g of MEK (Methyl Ethyl Ketone) and 524 g of 2-methoxy ethanol is added to the epoxy resin compositions 1 to 5 shown in Example 1 of Table 1, followed by stirring at 300 rpm at room temperature.

2) 735.56 g of irregularly shaped inorganic filler ⑦ having an average particle size distribution of 2.5 to 3 μm was added to the mixture of 1), followed by stirring at 400 rpm for 3 hours.

3) Finally, the curing agent of ⑥ and the curing accelerator of ⑧ was added to the mixture of 2) and stirred for about 30 minutes to prepare the final epoxy composition.

4) The above epoxy composition is cast in a PET film to prepare a roll.

5) Cut the above film into a size of 405 × 510 mm and lamination at 80 ℃, and then proceeds a series of drying and precure steps using a convection oven (convection oven).

6) Then, after the vertical desmear and chemical copper roughening step for forming roughness on the surface of the film, electroplating and postcuring with a thickness of 25 μm are performed to form an insulating layer of the printed circuit board.

7) The peeling strength measurement between the insulating layer and the plating layer, and the physical properties such as tensile and thermal properties of the insulating material composition prepared as described above are shown in Table 2 below. Indicated.

Comparative Example 1

1) A mixed solvent of 316.54 g of MEK (Methyl Ethyl Ketone) and 623.88 g of 2-methoxy ethanol are added to the resin compositions of 2 to 5 shown in Example 1 of Table 1, followed by stirring at 300 rpm at room temperature.

2) To the mixture of 1) was added 588.45 g of irregularly shaped inorganic filler ⑦ having an average particle size distribution of 2.5 to 3 μm, followed by stirring at 400 rpm for 3 hours.

3) Finally, the curing agent of ⑥ and the curing accelerator of ⑧ was added to the mixture of 2) and stirred for about 30 minutes to prepare the final epoxy composition.

4) The subsequent steps are the same as in <Example 1> above.

Comparative Example 2

1) A mixed solvent of 316.54 g of MEK (Methyl Ethyl Ketone) and 561.14 g of 2-methoxy ethanol was added to the resin compositions of 1 to 5 shown in Example 1 of Table 1, followed by stirring at 300 rpm at room temperature.

2) 614.19 g of an irregularly shaped inorganic filler ⑦ having an average particle size distribution of 2.5 to 3 μm was added to the mixture of 1), followed by stirring at 400 rpm for 3 hours.

3) Finally, the curing agent of ⑥ and the curing accelerator of ⑧ was added to the mixture of 2) and stirred for about 30 minutes to prepare the final epoxy composition.

4) The subsequent steps are the same as in <Example 1> above.

As shown in Table 2, as the content according to the present invention includes TGIC (Example 1), the moisture absorption rate was slightly lower than that of Comparative Example 1 without TGIC, elongation and tensile strength (tensile). The strength was increased to confirm the effect of improving the toughness (toughness). In addition, it was found that the high temperature thermal shock test of the real substrate to which Example 1 was applied showed superior reliability characteristics compared to Comparative Example 1.

However, in the case of Comparative Example 2 containing more than the appropriate amount of TGIC, the moisture absorption rate was significantly increased compared to Comparative Example 1 containing no TGIC, resulting in delamination at high temperature thermal shock. It shows excellent properties when the TGIC participates in the curing reaction to form a three-dimensional curing structure and is used as part of the composition, but when used beyond a certain content, the unreacted TGIC is a whole epoxy composition having a structure that is vulnerable to moisture absorption. It is thought that this is because the moisture absorption rate of is lowered.

Although the present invention has been described in detail through specific embodiments, it is for explaining the present invention in detail, and the resin composition for a printed circuit board and the printed circuit board using the same according to the present invention are not limited thereto. It is apparent that modifications and improvements are possible by those skilled in the art within the scope of the idea.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

Claims (12)

1-8 wt% triglycidyl isocianurate (TGIC) resin, 1-20 wt% DGEBA (diglycidyl ether of bisphenol A) epoxy resin, 30-70 wt% cresol novolac epoxy resin Composite epoxy resins comprising from 20 to 30% by weight of phosphorus-based epoxy resins and from 1 to 20% by weight of rubber-modified epoxy resins; Bisphenol A curing agents; Curing accelerators; And Inorganic fillers; Resin composition for a printed circuit board comprising a. The method according to claim 1, The bisphenol A-based curing agent is a resin composition for a printed circuit board, characterized in that contained in 0.5 to 1.5 equivalents relative to the total mixed equivalent of the epoxy groups of the composite epoxy resin. The method according to claim 1, A resin composition for a printed circuit board comprising 0.1 to 1 part by weight of a curing accelerator and 10 to 30 parts by weight of an inorganic filler based on 100 parts by weight of the composite epoxy resin. The method according to claim 1, The average epoxy resin equivalents of the above (i) TGIC resin, (ii) DGEBA epoxy resin, (iii) cresol novolac epoxy resin, (iv) phosphorus epoxy resin and (v) rubber modified epoxy resin are respectively (i) 85 -125, (ii) 200-600, (iii) 100-300, (iv) 400-800, and (v) 200-400, The resin composition for printed circuit boards. The method according to claim 1, The curing agent has a softening point of 100 to 140 ℃, hydroxyl group equivalent resin composition for a printed circuit board, characterized in that 100 to 150. The method according to claim 1, The curing agent is a resin composition for a printed circuit board, characterized in that the ratio of the epoxy group of the composite epoxy resin and the phenolic hydroxyl group of the curing agent is 1: 0.7 to 1: 1.3. The method according to claim 1, The curing accelerator is a resin composition for a printed circuit board, characterized in that the imidazole compound. The method of claim 7, The curing accelerator is at least one compound selected from the group consisting of 2-ethyl-4-methyl imidazole, 1- (2-cyanoethyl) -2-alkyl imidazole, 2-phenyl imidazole and mixtures thereof. Resin composition for a printed circuit board characterized in that. The method according to claim 1, The inorganic filler is a resin composition for a printed circuit board, characterized in that the surface treatment with a silane coupling agent. The method according to claim 1, The inorganic filler is a resin composition for a printed circuit board, characterized in that it has any one or two or more shapes of plate-like, cubic, colloidal and needle-like. The method according to claim 1, The average particle diameter of the inorganic filler is a resin composition for a printed circuit board, characterized in that 0.1 to 10㎛. Printed circuit board manufactured using the resin composition according to claim 1.