KR100495208B1 - Epoxy resin composition and method of manufacturing multilayer printed-wiring boards using the same - Google Patents

Abstract

The present invention, epoxy resin; About 10 to 80 wt% of a rubber component; About 1-50 wt%, filler; 0.1 to 40wt%, an epoxy curing agent in an amount corresponding to the equivalent of the epoxy resin, the filler provides an insulating resin composition coated with a surface at least a weak chemical resistance component than the epoxy resin. When the insulating layer of the multilayer printed circuit board is manufactured with the insulating resin composition according to the present invention, the coating film applied to the filler on the surface of the insulating layer is dissolved / decomposed by an oxidizing agent during the chemical roughening process, and the filler is insulated from the insulating layer. It can be discharged smoothly from the surface. Therefore, the adhesive strength with the conductive layer to be formed in a subsequent step can be significantly increased.

Description

 Insulation resin composition and manufacturing method of multilayer printed circuit board using the composition {EPOXY RESIN COMPOSITION AND METHOD OF MANUFACTURING MULTILAYER PRINTED-WIRING BOARDS USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an insulation composition for a multilayer printed circuit board. In particular, an insulating resin composition capable of forming a fine surface for improving adhesion strength with a plating layer in a multilayer printed circuit board and a multilayer printed circuit using the composition It relates to a method for manufacturing a substrate.

BACKGROUND With the recent trend toward lighter, shorter, and higher performance of electronic devices, miniaturization and high integration of printed circuit boards used in electronic devices are also strongly demanded.

To this end, a build-up multi-layer substrate, which manufactures a substrate by alternately stacking an insulating layer and a conductive layer for wiring, has appeared, contributing to miniaturization while implementing highly integrated wiring.

In a general method for manufacturing a multilayer printed circuit board, a conductive thin plate such as a cupper foil is laminated on an insulating layer surface, and the conductive thin plate is patterned to form a circuit. Subsequently, an additional insulating layer is laminated and a circuit is formed on the laminated insulating layer in the manner described above to produce the desired multilayer printed circuit board.

The insulating layer may be a prepreg impregnated with an insulating material such as epoxy resin in the glass croth, or a resin coated copper foil (RCC) or a photosensitive insulating material may be used, but prepreg or photosensitive insulating resin may be used. In the case of lamination, in order to mold under heat and pressure using a press during lamination, a large-scale facility is required and not only increases the cost, but also a step occurs during molding, making a non-uniform film easily formed, There is a problem that there is a limit (80 µm) in downsizing.

Therefore, in recent years, a dry film, which is a semi-solid insulating material, is favored for being advantageous in terms of process efficiency and uniform thickness. This allows the thickness of the insulating layer to be adjusted relatively accurately, which facilitates thinness, and has the advantage that via holes can be formed to a size of 50 μm or less by applying laser processing technology. However, when the electroless plating layer is formed to form an electroplating layer on the dry film type insulating layer, the adhesion between the electroless plating layer and the insulating layer is weak, so that the final conductive layer (conductive layer on which a predetermined circuit is to be formed) is formed. ), There is also a problem that the adhesive strength between the and the insulating layer is low.

In order to improve this, an insulating layer is formed using an insulating resin composition to have a fine rough surface during thermal curing, or a fine roughness of the surface is formed through a separate roughening process to improve adhesive strength between the insulating layer and the conductive layer. do.

In such a method using an appropriate insulating resin composition, the insulating resin composition containing a predetermined filler and / or rubber component is cured to form an insulating layer, and as shown in Figure 1, the insulating layer ( The filler 15 and the rubber component included in 10) are chemically roughened to be discharged from the surface thereof to form fine holes or protrusions. Referring to FIG. 1, a hole region a from which the filler 15 is removed and a region from which a rubber component is removed are formed on the roughened surface of the insulating layer 10 to form a rough surface b. In particular, the filler 15 may further remove the rubber component in the discharged region (a) to form a deeper hole. These holes are called anchors, which are formed on the surface as the conductive layer (especially the electroless plating layer) formed in the subsequent process is filled in the hole to increase the adhesive strength between the insulating layer and the conductive layer in the final product. do.

However, also in this method, since the filler 15 has relatively large particles, the filler (c) remaining on the surface is frequently generated without smooth discharge from the cured insulating layer. This phenomenon makes it difficult to obtain desired surface roughness according to the filler content even when the roughening treatment is performed. As a result, this problem is a great obstacle to increasing the adhesive strength of the insulating layer and the conductive layer.

As such, in the art, in order to increase the adhesive strength between the insulating layer and the conductive layer, a new insulating resin composition which ensures the smooth action (hole formation by discharge) of the filler contained in the insulating layer during the roughening process; There has been a strong demand for a method of manufacturing a multilayer printed circuit board using the same.

In order to solve the above problems, an object of the present invention is to properly fill the cured insulating layer in the chemical roughening process, the filler contained in the insulating layer is properly coated to form fine holes (or anchors) It is to significantly improve the adhesive strength with the conductive layer by providing an insulating resin composition comprising a.

Another object of the present invention is to provide a method for manufacturing a multilayer printed circuit board using an insulating resin composition including a filler coated to facilitate discharge in a roughening process.

In order to solve the said subject, this invention is an epoxy resin; About 10 to 80 wt% of a rubber component; About 1-50 wt%, filler; 0.1 to 40wt%, an epoxy curing agent in an amount corresponding to the equivalent of the epoxy resin, the filler provides an insulating resin composition coated with a surface at least a weak chemical resistance component than the epoxy resin.

Furthermore, the present invention provides a method of manufacturing a multilayer printed circuit board using the insulating resin composition. The method includes an epoxy resin; About 10 to 80 wt% of a rubber component; About 1-50 wt%, filler; 0.1 to 40 wt%, an epoxy curing agent in an amount corresponding to the equivalent of the epoxy resin, wherein the filler is at least a chemical resistance than the epoxy resin, the step of forming an insulating layer with an insulating resin composition coated with a surface, Performing a roughening treatment by applying an oxidant to a surface of the insulating layer on which the conductive layer is to be formed, forming a conductive layer on the surface of the insulating layer on which the roughening treatment is performed, and patterning the conductive layer To form a predetermined circuit, and repeating the above steps a number of times depending on the number of stacks of the desired printed circuit board.

Moreover, in preferable embodiment of this invention, in order to improve the heat resistance of an insulating layer and the dielectric constant, it is cyan-type resin; The metal catalyst for the cyan-based resin may be further included in an amount corresponding to about 1 to 80 wt% and the cyan-based resin equivalent.

The filler used in the present invention is preferably used by selecting at least one selected from the group consisting of barium sulfate powder, barium titanate powder, silicon oxide powder, amorphous silicon, talc, clay and mica powder, and the material for coating the filler As the furnace, it is preferable to use a substance selected from the group consisting of rubber components and derivatives thereof, plastic resins, non-reactive diluents and mixtures thereof.

Preferably, the rubber component which is the material for coating the filler is at least one selected from the group consisting of polybutadiene rubber, modified polybutadiene rubber, acrylonitrile-polybutadiene rubber, and acrylonitrile-modified polybutadiene rubber. The plastic resin may be at least one selected from the group consisting of styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), rosin, and wax, and the non-reactive diluent Dioctyl phthalate (DOP), dibutyl phthalate (DBP), DAP or mixtures thereof can be used.

The main feature of the present invention is to smoothly discharge the filler from the surface of the insulating layer in the chemical roughening process by coating the surface of the filler included in the insulating resin composition for forming the insulating layer with a material having a lower chemical resistance than the epoxy resin as a main component In order to increase the adhesive strength with the conductive layer to be formed in a subsequent step.

The epoxy resin used in the present invention is a component adopted to obtain an insulating layer having excellent electrical insulation and thermal / chemical stability as a substantial main component of the insulating resin composition. As the epoxy resin, a general epoxy resin known in the art may be used. Preferably, bisphenol epoxy and bisphenol F epoxy resin including bisphenol A type epoxy resin and bisphenol F type epoxy resin, as well as phenolic noblock type epoxy resin, may be used. Epoxy resins containing halides for imparting may be used.

Moreover, in order to harden the said epoxy resin, an epoxy resin hardening | curing agent is added in the quantity corresponding to the equivalent of the epoxy resin added. Such a curing agent may be an amine compound, an imidazole compound, an acid anhydride compound and the like, specifically 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-phenylimidazole, 2-ethyl 4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, triazine-added imidazole, phthalic an Hydride-based and the like can be used.

In addition, cyanate ester resin may be added to improve heat resistance and permittivity of the insulating layer. Specifically, the cyan-based resin may be PT-15, PT-30, PT-30S, PT-60, PT-60S, CT-90 and BA-230S manufactured by Lonza, Switzerland. In the case of using a cyan-based resin, a metal catalyst for the cyan-based resin should be used to react the cyan-based resin at a low temperature or to lower the curing temperature. Such metal catalysts include magnesium naphtanate, zinc naphtanate, cobalt, nickel naphtanate, cerium naphtanate, magnesium octet, zinc octet, cobalt octet, nickel octet, cerium octet, and the like.

In addition, the filler is added to remove the fine roughening process on the surface of the insulating layer (material) to form fine holes (or anchors) to increase the adhesive strength of the insulating layer and the plating layer. Such fillers may include barium sulfate, barium titanate, silicon oxide powder, silica powder, talc, clay, mica powder, and the like.

As described above, the filler applied in the present invention is coated with a material having a lower chemical resistance than at least an epoxy resin in order to facilitate smooth discharge during the surface treatment process. The coating material applied to the present invention is preferably a rubber component and its derivatives, plastic resins and non-reactive diluents. Specifically, in the case of a rubber component, it may be at least one material selected from the group consisting of polybutadiene rubber, modified polybutadiene rubber, acrylonitrile-polybutadiene rubber, and acrylonitrile-modified polybutadiene rubber, In the case of the plastic resins, the resin may be at least one material selected from the group consisting of styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), rosin, and wax. In addition, as the non-reactive diluent, dioctyl phthalate (DOP), dibutyl phthalate (DBP), dibutyl phthalate (DBP), DAP or mixtures thereof, which are well known in the art, may be used.

In addition, the solvent used in the present invention may be used by selecting a suitable solvent according to the type of resin or other components as is well known in the art. The solvent is used as the remainder of the base composition containing the epoxy resin, rubber component and filler.

2A and 2B will be described a roughening process for the insulating layer 10 formed of the insulating resin composition of the present invention. The insulating resin composition adopted in the present invention forms the desired insulating layer 10 as shown in FIG. 2A. The filler 15 contained in the insulating resin composition is impregnated with a coating material having a weaker chemical resistance than the epoxy resin, and the coating film 17 is formed on the outer surface thereof, and is evenly distributed in the cured insulating layer 10.

In the insulating layer 10 shown in FIG. 2A, a roughening process is applied in a conventional manner to the surface on which the conductive layer is to be formed (herein, the insulating layer upper surface). In this way, oxidizing agents such as permanganate, dichromate and hydrogen peroxide are used. At this time, the reaction occurs in the order of oxidation / reduction reaction through the swelling process. This roughened insulating layer is schematically shown in Fig. 2B. Referring to FIG. 2B, the rubber component and / or its derivative, which is a component of the insulating resin composition, is removed to form a groove (b), and the filler 15 coated with a weak chemical resistant resin is decomposed into a coating film 17. As dissolved / dissolved, as shown in FIG. 1, almost all of the fillers 15 located on the surface from the insulating layer 10 may be released. As a result, the space (a) from which the filler 15 is discharged through the entire surface is provided in a plurality of hole shapes, and further, rubber components and / or derivatives thereof are additionally removed in the portion separated by the action of the oxidant, thereby deepening the hole structure. It can be effectively formed with an anchor having a.

In this way, the insulating resin composition according to the present invention can be effectively carried out a fine roughening treatment, it is possible to greatly increase the adhesive strength between the insulating layer and the conductive layer by a fine hole and anchor structure when forming the conductive layer in a subsequent process. have.

The present invention also includes a method of manufacturing a multilayer printed circuit board using an insulating layer obtained from such an insulating resin composition. On the surface of the insulating layer formed of the insulating resin composition provided in the present invention, an oxidizing agent is applied to the surface on which the conductive layer is to be formed, and then a roughening treatment is formed on the surface of the insulating layer on which the roughening treatment is performed. do. In order to form a higher quality conductive layer, it is preferable to form the conductive layer by performing electroplating after the electroless plating layer is formed. The conductive layer thus obtained is patterned to form a predetermined circuit, and these processes are repeatedly performed according to the number of stacks of the desired printed circuit board to form a multilayer printed circuit board having excellent adhesive strength between the conductive layer and the insulating layer forming the circuit. It can manufacture.

Hereinafter, the effect of the insulating layer formed of the insulating resin composition according to the present invention will be described in more detail through examples.

(Example 1)

First, in order to obtain the insulating composition of the present invention, with cellulose, together with 20% bisphenol A type epoxy resin, 25% bisphenol F type epoxy resin, 30% phenol noblock type phenol resin and 15% polybutadiene rubber, 5% of the coated 0.5-2 μm spherical SiO ₂ filler was properly mixed, followed by additional addition of a small amount of silicone-based antifoaming agent and other additives, followed by stirring again. Next, methylbutenyltetrahydro phthalic anhydride and 2-methylimidazole were added as a hardening | curing agent, and the insulating layer was manufactured.

The surface to be roughened among the insulating layers thus prepared is swelled using a swelling dip P (trade name of Atotech Co., Ltd.) and sodium hydroxide solution, followed by Concentrate Compact CP: A fine etching process was applied to a mixed solution of Japan Atotech Co., Ltd.), potassium dichromate and sodium hydroxide. Subsequently, after the etched surface was washed, a reduction treatment was performed using a reducing solution and sodium sulfate solution to complete the roughening process.

Next, after removing and washing the contaminated organic material on the surface of the roughened insulating layer, a seed layer is formed using palladium (Pd), and after activating the Pd seed layer, the electroplating process is performed to copper. A plating layer was formed.

Finally, after washing using a mixed solution of Acid Creaner FR (trademark of Atotech Japan) and sodium sulfate on the plating layer obtained by the electroless plating process, a final plating layer was formed toward the electroplating process. .

The adhesion strength between the insulating layer and the plating layer thus obtained was evaluated by a method of measuring peeling strength according to JIS C 6481 standard.

(Example 2)

In this embodiment, after mixing arsenic phenol A type epoxy resin, arsenic phenol F type epoxy resin, phenol noblock type resin and phenolbutadiene rubber in the same ratio as in the first embodiment, 1 to 2 μm sized spherical SiO coated with SAN _{2 Add} 10% filler and stir. Subsequently, a small amount of the silicone-based antifoaming agent and other additives were added, followed by stirring, and an insulating layer was prepared by adding the same components and amounts of curing agents as those of the first embodiment.

The resulting insulating layer was subjected to the same roughening process and plating process as in the first embodiment to form a conductive layer on one surface of the insulating layer, and to evaluate the adhesive strength between the conductive layer and the insulating layer. Peel strength was measured in the same way.

(Example 3)

In this embodiment, the insulating layer was formed by using the insulating resin composition obtained under the same components and conditions as those of the first and second embodiments, by changing only the filler and the material coated on the filler. The filler used in this example was a spherical SiO ₂ having a size of 3 to 5 mm and its surface was coded with rosin, and about 20% was added to the insulating resin composition.

The resulting insulating layer was subjected to the same roughening process and plating process as in the first embodiment to form a conductive layer on one surface of the insulating layer, and to evaluate the adhesive strength between the conductive layer and the insulating layer. Peel strength was measured in the same manner as in Example.

(Comparative Example)

In this comparative example, cellulose is used together with 20% bisphenol A type epoxy resin, 25% bisphenol F type epoxy resin, 30% phenol noblock type phenol resin and 15% polybutadiene rubber in the same manner as the above embodiments. 5% of the SiO ₂ filler having a spherical size of 0.5-1 μm coated with Si was properly mixed, and then a small amount of silicon-based antifoaming agent and other additives were added, followed by stirring again. However, the filler was stirred by adding only 10% of the total weight as it is in the conventional manner without forming a coating film of SiO ₂ having a spherical size of 1 ~ 2㎛.

 The resulting insulating layer was subjected to the same roughening process and plating process as in the first embodiment to form a conductive layer on one surface of the insulating layer, and the peel strength was measured in order to evaluate the adhesive strength between the conductive layer and the insulating layer. It was.

As such, the adhesion strengths of the insulating layers and the conductive layers obtained through the first to third embodiments and the comparative examples are shown in Table 1 below.

Adhesive Strength (kg · f / cm, Avg.) Adhesion Strength Improvement Rate Example 1 1.0 43% Example 2 0.8 14% Example 3 0.9 29% Comparative example 0.7 0%

Through Table 1, it can be seen that the adhesive strength with the conductive layer in the insulating layer including the filler coated with a material having a weaker chemical resistance than the epoxy resin is up to 14% to 43%. As described above, in the multilayer printed circuit board manufactured using the insulating resin composition according to the present invention, the adhesive strength between the insulating layer and the conductive layer can be significantly improved as compared with the conventional art.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims, and various forms of substitution, modification, and within the scope not departing from the technical spirit of the present invention described in the claims. It will be apparent to those skilled in the art that changes are possible.

The insulating layer formed of the insulating resin composition according to the present invention may smoothly discharge the filler during the roughening process to form fine holes (or anchors), thereby significantly improving the adhesive strength with the conductive layer.

1 is a schematic cross-sectional view showing a conventional roughened insulating layer.

2A and 2B are schematic cross-sectional views showing an insulating layer made of an insulating resin composition and a roughened insulating layer according to the present invention.

<Code Description of Main Parts of Drawing>

10: insulating layer 15: filler

17: filler coating film

Claims (11)

Epoxy resins; 10 to 80 wt%, rubber component; 1-50 wt%, filler; 0.1-40 wt%; And as a remainder, the total amount of the solvent to be 100wt%, an epoxy curing agent in an amount corresponding to the equivalent of the epoxy resin is added, the filler is characterized in that the surface is coated with a material having a lower chemical resistance than at least the epoxy resin Insulation resin composition. The method of claim 1, Cyan resin; 1 to 80 wt%, wherein the epoxy resin, the rubber component, the filler, and the cyan-based resin are added so that the sum is 100 wt%, and together with the epoxy hardener, an amount corresponding to the cyan-based resin equivalent Insulating resin composition, characterized in that the metal catalyst for resin is further added. The method of claim 1, The filler is an insulating resin composition, characterized in that made of at least one selected from the group consisting of barium sulfate powder, barium titanate powder, silicon oxide powder, amorphous silicon, talc, clay and mica powder. The method of claim 1, Insulating resin composition, characterized in that the material used to coat the surface of the filler is selected from the group consisting of rubber components and derivatives thereof, plastic resins, non-reactive diluents and mixtures thereof. The method of claim 4, wherein The rubber component used to coat the surface of the filler is at least one selected from the group consisting of polybutadiene rubber, modified polybutadiene rubber, acrylonitrile-polybutadiene rubber, and acrylonitrile-modified polybutadiene rubber. Insulation resin composition, characterized in that. The method of claim 4, wherein The plastic resin may be at least one selected from the group consisting of styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), rosin, and wax. The method of claim 4, wherein The non-reactive diluent is an insulating resin composition, characterized in that consisting of dioctyl phthalate (DOP), dibutyl phthalate (DBP), DAP or mixtures thereof. Epoxy resins; 10 to 80 wt%, rubber component; 1-50 wt%, filler; 0.1-40 wt%; And as a balance, the solvent is added so that the sum is 100wt%, and an epoxy curing agent in an amount corresponding to the equivalent of the epoxy resin is added, and the filler is at least coated with a material having a lower chemical resistance than the epoxy resin. Forming an insulating layer from the resin composition; Performing a roughening treatment by applying an oxidizing agent to a surface of the insulating layer on which a conductive layer is to be formed; Forming a conductive layer on a surface of the insulating layer on which the roughening treatment has been performed; Patterning the conductive layer to form a circuit; And, And repeating the steps according to the number of stacks of the desired printed circuit board. The method of claim 8, Cyan resin; 1 to 80 wt%, wherein the epoxy resin, the rubber component, the filler, and the cyan-based resin are added so that the sum is 100 wt%, and together with the epoxy hardener, an amount corresponding to the cyan-based resin equivalent A method of manufacturing a multilayer printed circuit board, wherein a metal catalyst for resin is further added. The method of claim 8, The material used to coat the surface of the filler is a material selected from the group consisting of rubber components and derivatives thereof, plastic resins, non-reactive diluents and mixtures thereof. The method of claim 8, The forming of the conductive layer is a method of manufacturing a multilayer printed circuit board, characterized in that after forming the electroless plating layer to form a conductive layer by applying electroplating.