JP6950132B2 - A low dielectric loss insulating resin composition, an insulating film produced by the composition, and a printed circuit board provided with the insulating film. - Google Patents

Description

The present invention relates to an insulating resin composition having a low dielectric loss, an insulating film produced by the composition, and a printed circuit board provided with the insulating film.

In recent years, due to the miniaturization of electronic components, it is necessary to integrate a large number of electronic components in a small area in a printed circuit board on which electronic components are mounted, and a high density of circuit patterns is required.

As the circuit pattern of the printed circuit board becomes finer and the inter-layer spacing of the circuit becomes narrower, defects such as dielectric loss and short circuit, or the adhesion between the circuit and the insulator are reduced, and the reliability of the product is lowered. The problem has arisen. For this reason, a photosensitive insulating film capable of forming a fine opening pattern is used in a printed circuit board, a semiconductor package substrate, a flexible printed circuit board, or the like.

As the resin composition for low dielectric loss known so far, research on a resin composition containing an inorganic filler such as silica using a thermosetting resin and a phenolic curing agent has been generally conducted.

Generally, as the epoxy resin, bisphenol A-based epoxy is mainly used, and this resin has excellent thermal and mechanical properties and adhesive properties.

However, due to the presence of a large amount of secondary hydroxyl groups formed after curing, it has a disadvantage of having a high dielectric constant and dielectric loss tangent characteristics, and its use as an epoxy resin for low dielectric loss has been limited.

In recent years, research has been conducted on the development of a low dielectric loss insulating material using a cyanate ester resin and an olephine resin as a biphenyl epoxy resin having structurally hydrophobic properties or a novel curable resin.

However, although the cyanate ester resin itself has excellent dielectric properties, it is difficult to use because it requires the use of a metal catalyst, has the disadvantage of being easily brittle, and is expensive.

Further, in the case of an olephine-based resin, although it has excellent dielectric properties as a thermoplastic resin, when a high content is used, the physical properties are deteriorated due to insufficient compatibility with the existing thermosetting resin and wet (wet). There was a disadvantage that it was disadvantageous to the process.

Japanese Unexamined Patent Publication No. 2003-147052

The insulating resin composition according to an embodiment of the present invention may contain an epoxy resin containing one or more silyl groups, a curing agent, and a filler.

The epoxy resin can be a biphenyl-based epoxy resin or a bisphenol A-based epoxy resin containing one or more silyl groups.

The filler can be contained in 70 to 90 parts by weight of the total amount of the epoxy resin and the curing agent.

The epoxy resin and the curing agent can be contained in an equivalent ratio of 1: 0.5 to 1: 1.

The composition may further contain an epoxy resin that does not contain a silyl group.

The curing agents include active ester curing agent, aminotriazine novolac curing agent, amide curing agent, polyamine curing agent, acid anhydride curing agent, phenol novolac type curing agent, polymercaptan curing agent, tertiary amine curing agent, and One or more can be selected from the imidazole curing agents.

The curing agent may be one or more of active ester and aminotriazine.

The insulating film according to an embodiment of the present invention can be produced by applying the above insulating resin composition on a substrate and semi-curing it.

The dielectric loss tangent property (Df: Dissipation factor) of the insulating film may be 0.0050 tangent δ or less.

The prepreg according to an embodiment of the present invention can be produced by impregnating a varnish containing the above insulating resin composition with inorganic fibers or organic fibers and drying the varnish.

The printed circuit board according to an embodiment of the present invention can be manufactured by laminating the insulating film on a base material on which a circuit pattern is formed.

In the method for producing an insulating resin composition according to an embodiment of the present invention, the coefficient of thermal expansion and the dielectric loss tangent property of the insulating resin composition can be adjusted by adjusting the number of silyl groups introduced into the silicate epoxy. ..

It is sectional drawing which shows typically the printed circuit board which was laminated with the insulating film which concerns on one Example of this invention. It is a structural drawing of one example of the sililate epoxy resin used in the Example of this invention. It is a structural drawing of another example of the sililate epoxy resin used in the Example of this invention. It is a structural drawing of another example of the sililate epoxy resin used in the Example of this invention. It is a structural drawing of another example of the sililate epoxy resin used in the Example of this invention.

Prior to describing the present invention more specifically, the terms and words used herein and in the scope of the patent claims should not be construed in a general or lexical sense, and the invention is best described. It must be interpreted with meanings and concepts that are consistent with the technical ideas of the invention in accordance with the principle that the concepts of terms can be properly defined to explain in a way.

Therefore, the configurations of the examples described herein are merely one example of the present invention and do not represent all the technical ideas of the present invention, and therefore, various alternatives can be made at the time of the present application. It must be understood that there can be equivalents and variants.

Hereinafter, an embodiment of the present invention will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention belongs can easily carry out the present invention. Further, in explaining the present invention, detailed description of the publicly known technique which is determined to obscure the gist of the present invention will be omitted.

<Sililate epoxy resin>
The insulating resin composition according to an embodiment of the present invention can contain a silylate epoxy resin containing a Si group in the epoxy resin.

The silicate epoxy resin can include an epoxy resin in which one or more silicate groups are substituted with epoxies having various structures.

In the present invention, the epoxy resin has two or more epoxy groups and can be contained in an amount of 1 to 30 parts by weight with respect to 100 parts by weight of the insulating resin composition, and is a naphthalene-based epoxy resin, bisphenol A type. One or more types can be selected from, but are not limited to, epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, rubber-modified epoxy resins, and phosphorus-based epoxy resins.

The silicate epoxy resin may contain one or more silicate epoxy resins represented by the following chemical formulas.

<Hardener>
The insulating resin composition according to an embodiment of the present invention may contain a silylate epoxy resin and a curing agent. The curing agent can include a curing agent capable of reacting with an epoxy group usually contained in an epoxy resin, and is not particularly limited.

The curing agent can be contained in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the insulating resin composition, and is an active ester curing agent, an aminotriazine novolac curing agent, an amide-based curing agent, and a polyamine-based curing agent. One or more can be selected from, but is not limited to, an agent, an acid anhydride curing agent, a phenol novolac type curing agent, a polymercaptan curing agent, a tertiary amine curing agent, or an imidazole curing agent.

The epoxy resin and the curing agent can be contained in an equivalent ratio in the range of 1:05 to 1: 1.

The epoxy resin composition according to the present invention may further contain a curing accelerator for the purpose of adjusting the curing time and the curing temperature. Examples of the curing accelerator include, but are not limited to, 2-ethyl-4 methylimidazole, 1- (2-cyanoethyl) -2-alkylimidazole, 2-phenylimidazole, and a mixture thereof. At least one selected from the group can be used.

<Inorganic filler>
The insulating resin composition according to an embodiment of the present invention may further contain an inorganic filler in order to improve the coefficient of thermal expansion.

The amount of the inorganic filler used is not particularly limited, and may include 1 to 100 parts by weight with respect to 100 parts by weight of the resin composition. It can contain 70 to 90 parts by weight of the total amount of the epoxy resin and the curing agent. If the amount of the inorganic filler used is less than 70 parts by weight, the thermal expansion coefficient and dielectric properties of the resin composition are high, which may make it difficult to use as a substrate material for low dielectric loss, and exceeds 90 parts by weight. Then, the peel strength from the metal layer may be reduced, making it difficult to apply to the substrate process.

Examples of the inorganic filler include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), barium sulfate (BaSO ₄ ), aluminum hydroxide (AlOH ₃ ), magnesium hydroxide (Mg (OH) ₂ ), and calcium carbonate (Mg (OH) 2). CaCO ₃ ), Magnesium Carbonate (MgCO ₃ ), Magnesium Oxide (MgO), Boron Nitride (BN), Silicon Carbide (SiC), Aluminum Borate (AlBO ₃ ), Barium _{Titanate (BaTIO 3} ), and Calcium Zirconate (BaTIO 3) One or more types can be selected from CaZrO ₃ ), and the present invention is not limited to this.

The inorganic filler can contain surface-treated silica, which can be surface-treated silica with aminophenylsilane. The particle size of the silica may be 0.5 to 2 μm.

<Insulation film, prepreg, and printed circuit board>
The insulating resin composition according to an embodiment of the present invention can produce a film in a semi-solid phase state by using any general method known in the art. For example, it is produced in the form of a film using a roll coater, a curtain coater, a comma coater, or the like, dried, and then applied onto a substrate by a build-up method. It can be used as an insulating film or prepreg when manufacturing a multilayer printed circuit board. Such an insulating film or prepreg can improve the properties of heat resistance, coefficient of thermal expansion, dielectric constant and dielectric loss.

As described above, the varnish containing the insulating resin composition according to the embodiment of the present invention is impregnated with inorganic fibers, organic fibers, or the like and then cured to produce a prepreg, to which copper foil is attached to one or both sides. The copper-clad laminate can be manufactured.

The inorganic fibers or organic fibers include glass fibers, carbon fibers, polyparaphenylene benzobisoxazole fibers, thermotropic liquid crystal polymer fibers, liotropic liquid crystal polymer fibers, aramid fibers, polypyridobis imidazole fibers, and polybenzo. One or more can be selected from the thiazole fiber and the polyarylate fiber, and the present invention is not limited thereto.

Further, the insulating film produced by the above resin composition can be laminated on a copper-clad laminate used as an inner layer at the time of producing a multilayer printed circuit board and used for producing a multilayer printed circuit board.

For example, an insulating film produced of the above resin composition is laminated on a patterned inner layer circuit board, cured at a temperature of about 80 to 110 ° C. for about 30 minutes, and subjected to a desmere step, and then electroless. A multilayer printed circuit board can be manufactured by forming a circuit layer using an electrolytic plating and an electroplating process.

FIG. 1 is a cross-sectional view schematically showing a printed circuit board on which an insulating film according to an embodiment of the present invention is laminated.

Referring to FIG. 1, the printed circuit board according to the embodiment of the present invention includes insulating layers 11, 12, and 13, and the insulating layers 11, 12, and 13 are manufactured by using the insulating resin composition according to the present invention. It is a thing.

The dielectric loss tangent characteristic (Df: Dissipation factor) of the insulating layers 11, 12, and 13 included in the circuit board is 0.0050 tangent δ, and the coefficient of thermal expansion characteristic is improved.

Further, in the method for producing an insulating resin composition according to an embodiment of the present invention, the coefficient of thermal expansion and the dielectric loss tangent property of the insulating resin composition are adjusted by adjusting the number of silyl groups introduced into the silicate epoxy. Can be done.

<Manufacturing of insulating resin composition>
[Example 1]
The equivalent ratio of the epoxy resin to the curing agent was fixed at 1: (0.7: 0.15). As shown in FIG. 2a, a resin in which two silyl groups are substituted is used as the silylate epoxy, and 1 μm silica having an amine group on the surface treated with aminophenylsilane is used as the filler silica. board. The content of silica was set to 80% by weight of the total amount of the resin and the curing agent, polyvinyl butyral, which is a thermoplastic polymer, was used as an additive, and an imidazole system was used as a curing catalyst. A PDMS-based leveling substance was used to improve the film leveling characteristics. All the components were uniformly mixed by stirring to produce a resin composition 1 for an insulating film.

[Example 2]
As the silicate epoxy resin, as shown in FIG. 2b, a resin for an insulating film was used in the same manner as in Example 1 except that a resin in which two or one silyl group was substituted was used at 50:50. Composition 2 was produced.

[Example 3]
As the silicate epoxy resin, a resin composition 3 for an insulating film was produced by the same method as in Example 1 except that a resin in which one silyl group was substituted was used as shown in FIG. 2c.

[Example 4]
As the silicate epoxy resin, an insulating film was used in the same manner as in Example 1 except that a resin in which one silyl group was substituted and a resin in which the silyl group was not substituted were used at 50:50 as shown in FIG. 2d. Resin composition 4 for use was produced.

[Example 5]
As the epoxy resin, a bisphenol A resin, an o-cresol novolak resin, and a silylate epoxy in which two silyl glumes shown in FIG. 2a were substituted were used, and aminotriazine was used as a curing agent. Here, the equivalent ratio of the epoxy resin was 0.4: 0.1: 0.5 for the bisphenol A resin, the O-cresol novolak resin, and the silylate epoxy. The equivalent ratio of the epoxy resin and the curing agent was fixed at 1: 0.6. As the silica as the filler, 1 μm silica having been surface-treated with aminophenylsilane and containing an amine group on the surface was used.

The silica content was adjusted to 80 parts by weight of the total amount of the resin and the curing agent. Polyvinyl butyral, which is a thermoplastic polymer, was used as an additive, and an imidazole type was used as a curing catalyst. A PDMS-based leveling substance was used to improve the film leveling characteristics. All the components were uniformly mixed by stirring to produce a resin composition 5 for an insulating film.

[Comparative Example 1]
As the epoxy resin, unsilylated bisphenol A resin and o-cresol novolak resin were used at an equivalent ratio of 0.5: 0.5 so that the silica content was 75% by weight of the total amount of the resin and the curing agent. Except for this, the composition of Comparative Example was produced using the same method as in Example 1.

[Examples 6 to 10]
The resin compositions 1 to 5 for insulating films obtained in Examples 1 to 5 were filmed to 20 μm. The obtained film was cured by a three-step curing step to produce insulating films 1 to 5.

The three-step curing step was performed at 120 ° C./30 minutes, 180 ° C./30 minutes, and 230 ° C./60 minutes.

[Comparative Example 2]
An insulating film of Comparative Example was produced using the same method as in Example 6 except that the composition of Comparative Example 1 was used.

[Experimental example]
The coefficient of thermal expansion and the dielectric loss tangent characteristics were measured for the insulating films 1 to 5 obtained in Examples 6 to 10 and the insulating films of Comparative Examples obtained in Comparative Example 2, and the results are shown in Table 1. Indicated. The coefficient of thermal expansion was measured using a dynamic mechanical analysis (DMA) (measurement sample standard: length 4 cm, width 4 mm, thickness 100 μm). Dielectric properties were measured using Agilent E8632 PNA equipment and a capacity method (measurement sample standard: length 8 cm, width 3 mm, thickness 100 μm).

The printed circuit board as shown in FIG. 1 can be manufactured by using the insulating films 1 to 5 obtained in Examples 6 to 10 described above.

FIG. 1 is a cross-sectional view (11 to 13: insulating film, 21: horizontal wiring, 22: via electrode) schematically showing a printed circuit board, and is dielectrically tangent to the insulating layers 11, 12, and 13 included in the circuit board. It is possible to provide a printed circuit board having excellent characteristics having a characteristic (Df: Division factor) of 0.0050 tangent δ or less.

According to Examples 6 to 10 described above, the dielectric loss tangent characteristic of the coefficient of thermal expansion of the insulating resin composition can be adjusted by adjusting the number of silyl groups introduced into the silicate epoxy.

The present invention has been described in detail with reference to specific examples, but this is merely for explaining the present invention in detail, and the present invention is not limited thereto, and the present invention is not limited thereto. It is clear that it can be modified or improved by a person who has ordinary knowledge in the field within the technical idea of.

All simple modifications and modifications of the present invention belong to the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims.

Claims (9)

A bisphenol A-based epoxy resin containing one or more triethoxysilyl groups and 2-propenyl groups,
Hardener and
With filler
Insulating resin composition containing. The insulating resin composition according to claim 1, wherein the filler contains 70 to 90 parts by weight of the total amount of the bisphenol A epoxy resin and the curing agent. The insulating resin composition according to claim 1 or 2, wherein the bisphenol A-based epoxy resin and the curing agent have an equivalent ratio in the range of 1: 0.5 to 1: 1. The insulating resin composition according to any one of claims 1 to 3, further comprising an epoxy resin containing no silyl group. The curing agents include an active ester curing agent, an aminotriazine novolak curing agent, an amide curing agent, a polyamine curing agent, an acid anhydride curing agent, a phenol novolac type curing agent, a polymercaptan curing agent, a third amine curing agent, and a third amine curing agent. The insulating resin composition according to any one of claims 1 to 4, wherein one or more of the imidazole curing agents are selected. An insulating film formed on a substrate by the insulating resin composition according to any one of claims 1 to 5. The insulating film according to claim 6, wherein the insulating film has a dielectric loss tangent property (Df: Dissipation factor) of 0.0050 tangent δ or less. A prepreg produced by impregnating a varnish containing the insulating resin composition according to any one of claims 1 to 5 with inorganic fibers or organic fibers and drying the varnish. A printed circuit board in which the insulating film according to claim 6 or 7 is laminated on a base material on which a circuit pattern is formed.

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