JP2018115334A - Epoxy resin material and multilayer substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin material which can obtain a cured product having a low dielectric loss tangent, and can effectively remove smear by a desmear treatment.SOLUTION: An epoxy resin material contains two or more kinds of epoxy resins, an active ester compound, a curing accelerator and an inorganic filler. In the epoxy resin material, a ratio of an epoxy equivalent of the two or more kinds of epoxy resins to an active ester group equivalent of the active ester compound is 1:0.8 to 1:1.2. A standard deviation σ of the epoxy equivalent determined by expression (1) of the two or more kinds of epoxy resins is 1/3 or more as large as an average epoxy equivalent m determined by expression (2) of the two or more kinds of epoxy resins.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an epoxy resin material that can be suitably used, for example, to obtain a cured product to be desmeared. The present invention also relates to a multilayer substrate using the above epoxy resin material.

  Conventionally, various resin compositions have been used to obtain electronic components such as laminates and printed wiring boards. For example, in a multilayer printed wiring board, a resin composition is used in order to form an insulating layer for insulating inner layers or to form an insulating layer located in a surface layer portion. Wiring, which is generally a metal layer, is laminated on the surface of the insulating layer.

  As an example of the above resin composition, Patent Document 1 below discloses a resin composition containing a cyclic olefin-based resin and a compound having an active ester group.

  Patent Document 2 below discloses a resin composition containing an epoxy resin, an active ester compound, and an alicyclic structure-containing phenoxy resin. Here, it is described that the resin composition may contain an inorganic filler.

JP 2006-278994 A JP 2010-1111859 A

  In a conventional resin composition, the dielectric loss tangent of a cured product obtained by curing the resin composition may not be sufficiently low.

  Moreover, when forming an insulating layer using the conventional resin composition as described in Patent Documents 1 and 2, a cured product layer obtained by curing the resin composition is formed, and then a via is formed in the cured product layer. After forming, the cured product layer may be desmeared.

  However, in the conventional resin composition, the smear in the via may not be sufficiently removed by the desmear treatment. In particular, when an active ester compound is used, there is a problem that it is difficult to sufficiently remove smear in the via.

  An object of the present invention is to provide an epoxy resin material capable of obtaining a cured product having a low dielectric loss tangent and further capable of effectively removing smear by desmear treatment, and using the epoxy resin material It is to provide a multilayer substrate.

  According to a wide aspect of the present invention, the composition includes two or more epoxy resins, an active ester compound, a curing accelerator, and an inorganic filler, the epoxy equivalent of the two or more epoxy resins, and the active ester compound. The ratio to the active ester group equivalent is 1: 0.8 to 1: 1.2, and the standard deviation σ of the epoxy equivalent determined by the following formula (1) of the two or more types of epoxy resins is the two types described above. The epoxy resin material which is 1/3 or more of the average epoxy equivalent m calculated | required by following formula (2) of the above epoxy resin is provided.

Standard deviation of epoxy equivalent σ = [{(m ₁ −m) ² + (m ₂ −m) ² +... + (M _n −m) ² } / (w ₁ / m ₁ + w ₂ / m ₂ + ... + w _n / m _n )] ^1/2 ... Formula (1)
Average epoxy equivalent m = (w ₁ + w ₂ +... + W _n ) / (w ₁ / m ₁ + w ₂ / m ₂ +... + W _n / m _n ) (2)
m ₁ : Epoxy equivalent of the first type epoxy resin m ₂ : Epoxy equivalent of the second type epoxy resin m _n : Epoxy equivalent of the nth type epoxy resin w ₁ : Solid weight of the first type epoxy resin w _2: 2 solids weight type eye epoxy resin w _n: solid weight of _n type second epoxy resin

  On the specific situation with the epoxy resin material which concerns on this invention, the epoxy resin with the lowest epoxy equivalent is uniformly disperse | distributed among this 2 or more types of epoxy resins in this epoxy resin material.

  On the specific situation with the epoxy resin material which concerns on this invention, the epoxy equivalent in the epoxy resin with the lowest epoxy equivalent among the said 2 or more types of epoxy resins is 130 or less.

  In a specific aspect of the epoxy resin material according to the present invention, the epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is an epoxy resin containing a nitrogen atom.

  On the specific situation with the epoxy resin material which concerns on this invention, this epoxy resin material is a B stage film shape | molded in the film form.

  According to a wide aspect of the present invention, there is provided a multilayer board comprising a circuit board and an insulating layer disposed on the circuit board, wherein the insulating layer is formed by curing the epoxy resin material described above. Provided.

  The epoxy resin material according to the present invention includes two or more types of epoxy resins, an active ester compound, a curing accelerator, and an inorganic filler, and further includes an epoxy equivalent of the two or more types of epoxy resins and an active ester of the active ester compound. Since the ratio to the group equivalent is 1: 0.8 to 1: 1.2, a cured product having a low dielectric loss tangent can be obtained, and further obtained by the formula (1) of the two or more types of epoxy resins. Since the standard deviation σ of the epoxy equivalent is 1/3 or more of the average epoxy equivalent m determined by the formula (2) of the above two or more types of epoxy resins, it is possible to effectively remove smear by desmear treatment. Become.

FIG. 1 is a partially cutaway front sectional view schematically showing a multilayer substrate using an epoxy resin material according to an embodiment of the present invention.

  Details of the present invention will be described below.

(Epoxy resin material)
The epoxy resin material according to the present invention includes two or more epoxy resins, an active ester compound, a curing accelerator, and an inorganic filler. In the epoxy resin material according to the present invention, the ratio of the epoxy equivalent of the two or more epoxy resins to the active ester group equivalent of the active ester compound is 1: 0.8 to 1: 1.2. In the epoxy resin material according to the present invention, the standard deviation σ of the epoxy equivalent determined by the following formula (1) of the two or more types of epoxy resins is 1/3 or more of the average epoxy equivalent m determined by the following formula (2). It is.

Standard deviation of epoxy equivalent σ = [{(m ₁ −m) ² + (m ₂ −m) ² +... + (M _n −m) ² } / (w ₁ / m ₁ + w ₂ / m ₂ + ... + w _n / m _n )] ^1/2 ... Formula (1)
Average epoxy equivalent m = (w ₁ + w ₂ +... + W _n ) / (w ₁ / m ₁ + w ₂ / m ₂ +... + W _n / m _n ) (2)
m ₁ : Epoxy equivalent of the first type epoxy resin m ₂ : Epoxy equivalent of the second type epoxy resin m _n : Epoxy equivalent of the nth type epoxy resin w ₁ : Solid weight of the first type epoxy resin w _2: 2 solids weight type eye epoxy resin w _n: solid weight n of _n type second epoxy resin, the number of types of the epoxy resin contained in the epoxy resin material according to the present invention.

  Furthermore, in the epoxy resin material according to the present invention, the ratio of the epoxy equivalent of the two or more types of epoxy resins to the active ester group equivalent of the active ester compound (epoxy equivalent: active ester group equivalent) is 1: 0.8. ~ 1: 1.2.

  By adopting the above-described configuration in the epoxy resin material according to the present invention, a cured product having a low dielectric loss tangent can be obtained, and smear can be effectively removed by a desmear treatment. In the epoxy resin material according to the present invention, smear can be sufficiently removed by a desmear treatment in a short time. When the dielectric loss tangent of the cured product is lowered, the transmission loss of the wiring is reduced when the wiring is formed on the cured product. By sufficiently removing smears of through-holes such as vias or through-holes by desmear treatment, the connection reliability between the wiring on one side and the wiring on the other side of the cured product is improved. In particular, by adopting the above-described configuration in the epoxy resin material according to the present invention, the cross-linking density is locally increased and the polarity is also increased in the cured product, so that smear can be effectively removed by desmear treatment.

  In the epoxy resin material according to the present invention, the ratio (epoxy equivalent: active ester group equivalent) of the epoxy equivalent of the two or more types of epoxy resins to the active ester group equivalent of the active ester compound is 1: 0.8 to 1. : 1.2. When the epoxy equivalent is relatively less than within the above range, curing failure occurs, resulting in a decrease in resin strength and poor heat resistance. If the active ester group equivalent is relatively less than within the above range, an unreacted epoxy group remains in the cured product, or a polar group is generated due to the reaction between the epoxy group and the epoxy group, resulting in poor dielectric loss tangent. Become. The ratio (epoxy equivalent: active ester group equivalent) is preferably 0.9 or more, and preferably 1.1 or less.

  In the present invention, two or more types of epoxy resins are used, and the epoxy equivalent is the amount of the epoxy group contained in the entire resin (the value obtained by dividing the solid content weight of each epoxy resin by the equivalent of each epoxy resin). ). For example, when 30 parts by weight of epoxy resin A having an epoxy equivalent of 300 is used in solids and 20 parts by weight of epoxy resin B having an epoxy equivalent of 200 in solids, the formula: 30/300 + 20/200 The amount of epoxy group substance is required.

  When two or more active ester compounds are used, the above active ester group equivalent is the amount of active ester group contained in the entire resin (the value obtained by dividing the solid content weight of each active ester compound by the equivalent of each active ester) ). For example, when using 30 parts by weight of an active ester compound A having an active ester equivalent of 300 in solids and 20 parts by weight of an active ester compound B having an active ester equivalent of 200 in solids, the formula: The substance amount of the active ester group is determined by 30/300 + 20/200.

  From the viewpoint of effectively removing smear by desmear treatment, the standard deviation σ is 1/3 or more of the average epoxy equivalent m. The standard deviation σ is preferably 2/5 or more of the average epoxy equivalent m.

  The epoxy resin material according to the present invention may be a paste or a film. The epoxy resin material according to the present invention may be a resin composition or a B-stage film in which the resin composition is formed into a film.

  The epoxy resin material according to the present invention preferably contains a thermoplastic resin.

  The epoxy equivalent of the epoxy resin (molecular weight per epoxy group) is preferably 90 or more, more preferably 100 or more, preferably 1000 or less, more preferably 800 or less. When the epoxy equivalent of the epoxy resin is equal to or higher than the lower limit, poor curing hardly occurs and mechanical strength can be secured. Further, since the crosslink density of the cured product is lowered and the polarity is lowered, the dielectric loss tangent is improved and the dielectric loss tangent is lowered. When the epoxy equivalent of the epoxy resin is not more than the above upper limit, the molecular weight between cross-linking points is lowered, heat resistance is improved, and thermal reliability is improved. Moreover, even if the filling amount of the inorganic filler is increased, an epoxy resin material having high fluidity can be obtained. Moreover, since the crosslink density of hardened | cured material increases and polarity increases, desmear property improves.

  By using two or more types of epoxy resins and controlling the relationship between the standard deviation σ and the average epoxy equivalent m to the above-mentioned range, the cross-linking density of the entire cured product is lowered and the polarity is lowered. Can be lowered. On the other hand, by increasing the standard deviation (variation) of the epoxy equivalent of the epoxy resin, a portion having a high crosslinking density can be locally formed in the cured product, and desmearing can be ensured because it is desmeared from that point.

  Hereinafter, the detail of each component used for the epoxy resin material which concerns on this invention is demonstrated.

[Epoxy resin]
The epoxy resin (epoxy compound) contained in the epoxy resin material is not particularly limited. A conventionally well-known epoxy resin can be used as this epoxy resin. The epoxy resin refers to an organic compound having at least one epoxy group. In the present invention, two or more kinds of epoxy resins are used.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, biphenyl novolac type epoxy resin, biphenol type epoxy resin, and naphthalene type epoxy resin. Fluorene type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin, epoxy resin having adamantane skeleton, epoxy resin having tricyclodecane skeleton, and triazine nucleus Examples thereof include an epoxy resin having a skeleton.

  The epoxy resin preferably has a biphenyl skeleton, and is preferably a biphenyl type epoxy resin. When the said epoxy resin has biphenyl frame | skeleton, the adhesive strength of hardened | cured material and a metal layer becomes still higher.

  The molecular weight of the epoxy resin is preferably 1000 or less. In this case, even if the content of the inorganic filler in the epoxy resin material is 60% by weight or more, an epoxy resin material having high fluidity can be obtained. For this reason, when an epoxy resin material is laminated on a board | substrate, an inorganic filler can be made to exist uniformly.

  The molecular weight of the epoxy resin and the molecular weight of the active ester compound described below are obtained from the structural formula when the epoxy resin or the active ester compound is not a polymer and when the structural formula of the epoxy resin or the active ester compound can be specified. It means the molecular weight that can be calculated. Moreover, when the said epoxy resin or active ester compound is a polymer, a weight average molecular weight is meant.

When two or more types of epoxy resins having the same epoxy equivalent are used, the standard deviation σ = 0 and does not satisfy more than one third of the average epoxy equivalent m. It is preferable that the epoxy resin is included. In the epoxy resin material, it is preferable that the epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is uniformly dispersed. When the epoxy resin having the lowest epoxy equivalent is uniformly dispersed, formation of a region where the amount of the epoxy resin having the lowest epoxy equivalent is low is suppressed, and as a result, smear is more effectively removed by desmear treatment. It becomes possible. In addition, among two or more types of epoxy resins having different epoxy equivalents, the epoxy resin having the lowest epoxy equivalent is uniformly dispersed, so that formation of a region having a small amount of the epoxy resin having the lowest epoxy equivalent can be suppressed. The smear can be more effectively removed by the desmear process. In addition, if the area of the area | region where the epoxy resin with the lowest epoxy equivalent does not exist is less than 10 micrometers ² , it is judged that the epoxy resin with the lowest epoxy equivalent is disperse | distributing uniformly.

  Among the two or more types of epoxy resins, the epoxy equivalent in the epoxy resin having the lowest epoxy equivalent is preferably 130 or less, more preferably 100 or less. When the epoxy equivalent in the epoxy resin having the lowest epoxy equivalent is less than the above upper limit, the average epoxy equivalent m is appropriately lowered, the increase in the molecular weight between crosslinking points is suppressed in the cured product, and the heat resistance of the cured product is further improved. To do. The lower limit of the epoxy equivalent in the epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is not particularly limited. 44 or more may be sufficient as the epoxy equivalent in the epoxy resin with the lowest epoxy equivalent among the said 2 or more types of epoxy resins.

  Of the two or more epoxy resins, the epoxy resin having the lowest epoxy equivalent is preferably an epoxy resin containing a nitrogen atom. In this case, as a result of the local polarity of the cured product being increased, it is possible to more effectively remove smear by desmear treatment.

  Examples of the epoxy compound containing a nitrogen atom include an epoxy resin having an amino group and an epoxy resin having a triazine ring, and commercially available products include “630” manufactured by Mitsubishi Chemical Corporation and “GAN” manufactured by Nippon Kayaku Co., Ltd. Examples thereof include “GOT”, “YH-434”, “YH-434L” manufactured by Tohto Kasei Co., Ltd., “TEPIC-SP” manufactured by Nissan Chemical Co., Ltd., and the like.

  The content of the epoxy resin having the lowest epoxy equivalent in the total of 100% by weight of the two or more epoxy resins is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 50% by weight or less, more preferably Is 30% by weight or less. When the content of the epoxy resin having the lowest epoxy equivalent is not less than the above lower limit and not more than the above upper limit, smear can be more effectively removed by the desmear treatment of the cured product.

[Active ester compound]
The epoxy resin material includes a curing agent in order to cure the epoxy resin.

  As the curing agent, cyanate ester compound (cyanate ester curing agent), phenol compound (phenol curing agent), amine compound (amine curing agent), thiol compound (thiol curing agent), imidazole compound, phosphine compound, acid anhydride, Examples include active ester compounds and dicyandiamide.

  In the present invention, an active ester compound is used as the curing agent. When an active ester compound is used as the curing agent, the generation of polar groups after curing is suppressed and the dielectric loss tangent of the cured product is reduced as compared with the case where other curing agents are used. In addition, you may use hardening | curing agents other than an active ester compound with an active ester compound to such an extent that the dielectric loss tangent of hardened | cured material does not increase too much.

  The active ester compound functions as an epoxy resin curing agent and has an active ester, and is not particularly limited. Compounds having two or more active ester groups are preferred. A conventionally known active ester compound can be used as the active ester compound. As for the said active ester compound, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the active ester curing agent include an active ester compound represented by the following formula (11) and an active ester compound represented by the following formula (12).

  In said formula (12), X represents a benzene ring or a naphthalene ring, k represents 0 or 1, and n represents 0.25-1.5 on the average of a repeating unit, respectively.

  Commercially available products of the above active ester compounds include “EXB9451”, “EXB9460”, “EXB9460S-65T”, “EXB-9416-70BK” (naphthalene skeleton, manufactured by DIC, active ester group equivalent of about 330), “HPC- 8000-65T "(diphthalate esterified product of dicyclopentadiene skeleton, manufactured by DIC, active ester group equivalent of about 223)," DC808 "(acetylated product of phenol novolac, manufactured by Mitsubishi Chemical Co., Ltd., active ester group equivalent of about 149), “YLH1026” (benzoylated phenol novolak, manufactured by Mitsubishi Chemical Corporation, active ester group equivalent of about 200), “YLH1030” (manufactured by Mitsubishi Chemical Corporation, active ester group equivalent of about 201), and “YLH1048” (manufactured by Mitsubishi Chemical Corporation, Active ester group equivalent of about 245)

  The molecular weight of the active ester compound is preferably 3000 or less. In this case, the content of the inorganic filler in the epoxy resin material can be increased, and an epoxy resin material having high fluidity can be obtained even if the content of the inorganic filler is large.

  The molecular weight of the active ester compound is preferably 1000 or less. In this case, even if the content of the inorganic filler in the epoxy resin material is 50% by weight or more, an epoxy resin material having high fluidity can be obtained.

  From the viewpoint of further increasing the resin strength in order to further suppress the curing failure, the active ester group equivalent of the active ester compound is preferably 500 or less. From the viewpoint of further reducing the dielectric loss tangent of the cured product and further reducing the transmission loss of the metal wiring on the cured product, the active ester group equivalent of the active ester compound is preferably 100 or more.

[Curing accelerator]
When the epoxy resin material contains a curing accelerator, the curing rate is further increased. By rapidly curing the epoxy resin material, the crosslinked structure in the cured product becomes uniform, the number of unreacted functional groups is reduced, and as a result, the crosslinking density is increased. The said hardening accelerator is not specifically limited, A conventionally well-known hardening accelerator can be used. As for the said hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Examples of the curing accelerator include imidazole compounds, phosphorus compounds, amine compounds, and organometallic compounds.

  Examples of the imidazole compound include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl- 2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-un Decylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2 ′ -Methyl Midazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6 [2′-Ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine Isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole Can be mentioned.

  Examples of the phosphorus compound include triphenylphosphine.

  Examples of the amine compound include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine and 4,4-dimethylaminopyridine.

  Examples of the organometallic compound include zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III).

  The content of the curing accelerator is not particularly limited. The content of the curing accelerator is preferably 0.01% by weight or more, and preferably 3% by weight or less, in 100% by weight of the total solid content contained in the epoxy resin material. When the content of the curing accelerator is not less than the above lower limit and not more than the above upper limit, the epoxy resin material is efficiently cured. Moreover, when content of the said hardening | curing agent is more than the said minimum, it is hard to produce a hardening defect and a heat resistant fall is suppressed. When the content of the curing agent is not more than the above upper limit, the storage stability of the epoxy resin material is further improved.

  “Solid content” refers to a non-volatile component that does not volatilize during molding or heating.

[Inorganic filler]
When the said epoxy resin material contains an inorganic filler, the dimensional change by the heat | fever of hardened | cured material becomes still smaller. Furthermore, the surface roughness of the surface of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased.

  Examples of the inorganic filler include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride.

  The surface roughness of the cured product is reduced, the adhesive strength between the cured product and the metal layer is further increased, finer wiring is formed on the surface of the cured product, and better insulation reliability is achieved by the cured product. From the viewpoint of imparting the above, the inorganic filler is preferably silica or alumina, more preferably silica, and still more preferably fused silica. By using silica, the coefficient of thermal expansion of the cured product is further reduced, the surface roughness of the surface of the cured product is effectively reduced, and the adhesive strength between the cured product and the metal layer is effectively increased. The shape of silica is preferably substantially spherical.

  The average particle size of the inorganic filler is preferably 10 nm or more, more preferably 50 nm or more, further preferably 150 nm or more, preferably 20 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less, and particularly preferably 1 μm or less. is there. When the average particle size of the inorganic filler is not less than the above lower limit and not more than the above upper limit, the size of the holes formed by the roughening treatment or the like becomes fine, and the number of holes increases. As a result, the adhesive strength between the cured product and the metal layer is further increased.

  A median diameter (d50) value of 50% is employed as the average particle diameter of the inorganic filler. The average particle size can be measured using a laser diffraction / scattering particle size distribution measuring apparatus.

  The inorganic filler is preferably spherical and more preferably spherical silica. In this case, the surface roughness of the surface of the cured product is effectively reduced, and the adhesive strength between the insulating layer and the metal layer is effectively increased. When the inorganic filler is spherical, the aspect ratio of the inorganic filler is preferably 2 or less, more preferably 1.5 or less.

  The inorganic filler is preferably surface-treated, and more preferably surface-treated with a silane coupling agent. Thereby, the surface roughness of the surface of the roughened cured product is further reduced, the adhesive strength between the cured product and the metal layer is further increased, and finer wiring is formed on the surface of the cured product, and more Better inter-wiring insulation reliability and interlayer insulation reliability can be imparted to the cured product.

  Examples of the coupling agent include silane coupling agents, titanate coupling agents, and aluminum coupling agents. Examples of the silane coupling agent include methacryl silane, acrylic silane, amino silane, imidazole silane, vinyl silane, and epoxy silane.

  The content of the inorganic filler is preferably 25% by weight or more, more preferably 30% by weight or more, still more preferably 40% by weight or more, and particularly preferably 50% by weight in 100% by weight of the total solid content contained in the epoxy resin material. % By weight or more, preferably 99% by weight or less, more preferably 85% by weight or less, still more preferably 80% by weight or less, and particularly preferably 75% by weight or less. When the total content of the inorganic filler is not less than the above lower limit and not more than the above upper limit, the surface roughness of the surface of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased, In addition, finer wiring is formed on the surface of the cured product, and at the same time, with this amount of inorganic filler, it is possible to lower the thermal expansion coefficient of the cured product as well as metal copper.

[Thermoplastic resin]
The epoxy resin material does not contain or contain a thermoplastic resin. The epoxy resin material preferably contains a thermoplastic resin. By using the thermoplastic resin, it is possible to suppress the deterioration of the embedding property of the epoxy resin material in the holes or irregularities of the circuit board and the unevenness of the inorganic filler. Further, since the melt viscosity can be adjusted by using the thermoplastic resin, the dispersibility of the inorganic filler is improved, and the epoxy resin material is difficult to wet and spread in an unintended region during the curing process. The thermoplastic resin is not particularly limited. A conventionally known thermoplastic resin can be used as the thermoplastic resin. As for the said thermoplastic resin, only 1 type may be used and 2 or more types may be used together.

  Examples of the thermoplastic resin include phenoxy resins, polyvinyl acetal resins, rubber components, and organic fillers. The thermoplastic resin is particularly preferably a phenoxy resin. Since the melt viscosity can be adjusted by using the phenoxy resin, the dispersibility of the inorganic filler is improved, and the epoxy resin material is difficult to wet and spread in unintended areas during the curing process. In addition, the use of the thermoplastic resin suppresses deterioration in embedding property of the epoxy resin material in the holes or irregularities of the circuit board and non-uniformity of the inorganic filler.

  Examples of the phenoxy resin include phenoxy resins having a skeleton such as a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a biphenyl skeleton, a novolac skeleton, a naphthalene skeleton, and an imide skeleton.

  Examples of commercially available phenoxy resins include “YP50”, “YP55” and “YP70” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and “1256B40”, “4250”, “4256H40” manufactured by Mitsubishi Chemical Corporation, “ 4275 "," YX6954BH30 "," YX8100BH30 ", and the like.

  The weight average molecular weight of the thermoplastic resin is preferably 5000 or more, and preferably 100,000 or less. The weight average molecular weight indicates a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

  The content of the thermoplastic resin is not particularly limited. The content of the thermoplastic resin (the content of the phenoxy resin when the thermoplastic resin is a phenoxy resin) is preferably 1% by weight in 100% by weight of the total solid content contained in the epoxy resin material according to the present invention. Above, more preferably 5% by weight or more, preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 15% by weight or less. When the content of the thermoplastic resin is not more than the above upper limit, the thermal expansion coefficient of the cured product is further reduced. Moreover, the embedding property with respect to the hole or the unevenness | corrugation of the circuit board of an epoxy resin material becomes favorable. When the content of the thermoplastic resin is not less than the above lower limit, the film-forming property of the epoxy resin material becomes high, and an even better insulating layer is obtained. When the content of the thermoplastic resin is not less than the above lower limit, the surface roughness of the surface of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased.

[solvent]
The epoxy resin material does not contain or contain a solvent. By using the solvent, the viscosity of the epoxy resin material can be controlled within a suitable range, and the coating property of the epoxy resin material that is a resin composition can be enhanced. Moreover, the said solvent may be used in order to obtain the slurry containing the said inorganic filler. As for the said solvent, only 1 type may be used and 2 or more types may be used together.

  Examples of the solvent include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, toluene, xylene, methyl ethyl ketone, Examples thereof include N, N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane, cyclohexane, cyclohexanone, and naphtha as a mixture.

  Most of the solvent is preferably removed before or when the epoxy resin material is cured. Therefore, the boiling point of the solvent is preferably 200 ° C. or lower, more preferably 180 ° C. or lower. The content of the solvent in the epoxy resin material is not particularly limited. The content of the solvent can be appropriately changed in consideration of the coating property of the epoxy resin material.

[Other ingredients]
For the purpose of improving impact resistance, heat resistance, resin compatibility and workability, etc., the above epoxy resin materials include leveling agents, flame retardants, coupling agents, colorants, antioxidants, UV degradation inhibitors, You may add other thermosetting resins other than an antifoamer, a thickener, a thixotropic agent, and the epoxy resin mentioned above.

  Examples of the coupling agent include silane coupling agents, titanium coupling agents, and aluminum coupling agents. Examples of the silane coupling agent include vinyl silane, amino silane, imidazole silane, and epoxy silane.

  Examples of the other thermosetting resins include polyphenylene ether resins, divinyl benzyl ether resins, polyarylate resins, diallyl phthalate resins, polyimide resins, benzoxazine resins, benzoxazole resins, bismaleimide resins, and acrylate resins.

(B stage film)
As a method for forming the resin composition into a film, for example, an extrusion molding method is used in which the resin composition is melt-kneaded using an extruder, extruded, and then formed into a film using a T-die or a circular die. And a casting molding method in which a resin composition containing a solvent is cast to form a film, and other conventionally known film molding methods. Especially, since it can respond to thickness reduction, the extrusion molding method or the casting molding method is preferable. The film includes a sheet.

  A B-stage film can be obtained by forming the resin composition into a film and drying it by heating at 90 to 200 ° C. for 1 to 180 minutes to such an extent that curing by heat does not proceed excessively.

  The film-like resin composition that can be obtained by the drying process as described above is referred to as a B-stage film. The B-stage film is a semi-cured product in a semi-cured state. The semi-cured product is not completely cured and curing can proceed further.

  The B-stage film may not be a prepreg. When the B stage film is not a prepreg, migration does not occur along a glass cloth or the like. Further, when laminating or pre-curing the B stage film, the surface is not uneven due to the glass cloth.

  The said resin composition can be used suitably in order to form a laminated film provided with a base material and the B stage film laminated | stacked on one surface of this base material. A B-stage film of a laminated film is formed from the resin composition.

  Examples of the base material of the laminated film include polyester resin films such as polyethylene terephthalate film and polybutylene terephthalate film, olefin resin films such as polyethylene film and polypropylene film, polyimide resin film, metal foil such as copper foil and aluminum foil, and the like. Can be mentioned. The surface of the base material may be subjected to a release treatment as necessary.

  When the epoxy resin material is used as an insulating layer of a circuit, the thickness of the insulating layer formed of the epoxy resin material is preferably equal to or greater than the thickness of a conductor layer (metal layer) that forms a circuit. The thickness of the insulating layer formed of the epoxy resin material is preferably 5 μm or more, and preferably 200 μm or less.

(Printed wiring board)
The said epoxy resin material is used suitably in order to form an insulating layer in a printed wiring board.

  The printed wiring board can be obtained, for example, by heat-pressing the B stage film using a B stage film formed of the resin composition.

  A metal foil can be laminated on one side or both sides of the B-stage film. The method for laminating the B-stage film and the metal foil is not particularly limited, and a known method can be used. For example, the B-stage film can be laminated on the metal foil using an apparatus such as a parallel plate press or a roll laminator while pressing with or without heating.

(Copper-clad laminate and multilayer board)
The said epoxy resin material is used suitably in order to obtain a copper clad laminated board. An example of the copper-clad laminate is a copper-clad laminate comprising a copper foil and a B stage film laminated on one surface of the copper foil. The B-stage film of this copper-clad laminate is formed from the above epoxy resin material.

  The thickness of the copper foil of the copper-clad laminate is not particularly limited. The thickness of the copper foil is preferably in the range of 1 to 50 μm. Moreover, in order to increase the adhesive strength between the insulating layer obtained by curing the epoxy resin material and the copper foil, the copper foil preferably has fine irregularities on the surface. The method for forming the unevenness is not particularly limited. Examples of the method for forming the unevenness include a formation method by treatment using a known chemical solution.

  Moreover, the said epoxy resin material is used suitably in order to obtain a multilayer substrate. As an example of the multilayer substrate, a multilayer substrate including a circuit substrate and an insulating layer stacked on the surface of the circuit substrate can be given. The insulating layer of the multilayer substrate is formed by curing the epoxy resin material. The insulating layer is preferably laminated on the surface of the circuit board on which the circuit is provided. Part of the insulating layer is preferably embedded between the circuits.

  In the multilayer substrate, it is preferable that the surface of the insulating layer opposite to the surface on which the circuit substrate is laminated is roughened.

  The roughening method can be any conventionally known roughening method and is not particularly limited. The surface of the insulating layer may be subjected to a swelling treatment before the roughening treatment.

  Moreover, it is preferable that the said multilayer substrate is further equipped with the copper plating layer laminated | stacked on the surface by which the roughening process of the said insulating layer was carried out.

  As another example of the multilayer board, the circuit board, the insulating layer laminated on the surface of the circuit board, and the surface of the insulating layer opposite to the surface on which the circuit board is laminated are laminated. And a multilayer substrate provided with copper foil. The insulating layer and the copper foil are formed by curing the B-stage film using a copper-clad laminate including a copper foil and a B-stage film laminated on one surface of the copper foil. It is preferable. Furthermore, it is preferable that the copper foil is etched and is a copper circuit.

  Another example of the multilayer substrate is a multilayer substrate including a circuit board and a plurality of insulating layers stacked on the surface of the circuit board. At least one of the plurality of insulating layers disposed on the circuit board is formed by curing the epoxy resin material. The multilayer substrate preferably further includes a circuit laminated on at least one surface of the insulating layer formed by curing the epoxy resin material.

  In FIG. 1, the multilayer substrate using the epoxy resin material which concerns on one Embodiment of this invention is typically shown with a partial notch front sectional drawing.

  In the multilayer substrate 11 shown in FIG. 1, a plurality of insulating layers 13 to 16 are laminated on the upper surface 12 a of the circuit substrate 12. Insulating layers 13-16 are hardened material layers. A metal layer 17 is formed in a partial region of the upper surface 12 a of the circuit board 12. Among the plurality of insulating layers 13 to 16, the metal layer 17 is formed in a partial region of the upper surface of the insulating layers 13 to 15 other than the insulating layer 16 located on the outer surface opposite to the circuit board 12 side. Has been. The metal layer 17 is a circuit. Metal layers 17 are respectively disposed between the circuit board 12 and the insulating layer 13 and between the stacked insulating layers 13 to 16. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of via hole connection and through hole connection (not shown).

  In the multilayer substrate 11, the insulating layers 13 to 16 are formed by curing the epoxy resin material according to the present invention. In this embodiment, since the surfaces of the insulating layers 13 to 16 are roughened, fine holes (not shown) are formed on the surfaces of the insulating layers 13 to 16. Further, the metal layer 17 reaches the inside of the fine hole. Moreover, in the multilayer substrate 11, the width direction dimension (L) of the metal layer 17 and the width direction dimension (S) of the part in which the metal layer 17 is not formed can be made small. In the multilayer substrate 11, good insulation reliability is imparted between an upper metal layer and a lower metal layer that are not connected by via-hole connection and through-hole connection (not shown).

(Roughening treatment and swelling treatment)
It is preferable that the said epoxy resin material is used in order to obtain the hardened | cured material by which a roughening process or a desmear process is carried out. The cured product includes a precured product that can be further cured.

  In order to form fine irregularities on the surface of the cured product obtained by precuring the epoxy resin material according to the present invention, the cured product is preferably roughened. Prior to the roughening treatment, the cured product is preferably subjected to a swelling treatment. It is preferable that the cured product is subjected to a swelling treatment after the preliminary curing and before the roughening treatment. However, the cured product is not necessarily subjected to the swelling treatment.

  As a method for the swelling treatment, for example, a method of treating a cured product with an aqueous solution or an organic solvent dispersion of a compound mainly composed of ethylene glycol or the like is used. The swelling liquid used for the swelling treatment generally contains an alkali as a pH adjuster or the like. The swelling liquid preferably contains sodium hydroxide. Specifically, for example, the swelling treatment is performed by treating the cured product with a 40 wt% ethylene glycol aqueous solution at a treatment temperature of 30 to 85 ° C. for 1 to 30 minutes. The swelling treatment temperature is preferably in the range of 50 to 85 ° C. When the temperature of the swelling treatment is too low, it takes a long time for the swelling treatment, and the adhesive strength between the cured product and the metal layer tends to be low.

  For the roughening treatment, for example, a chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfuric acid compound is used. These chemical oxidizers are used as an aqueous solution or an organic solvent dispersion after water or an organic solvent is added. The roughening liquid used for the roughening treatment generally contains an alkali as a pH adjuster or the like. The roughening solution preferably contains sodium hydroxide.

  Examples of the manganese compound include potassium permanganate and sodium permanganate. Examples of the chromium compound include potassium dichromate and anhydrous potassium chromate. Examples of the persulfate compound include sodium persulfate, potassium persulfate, and ammonium persulfate.

  The method for the roughening treatment is not particularly limited. As a method of the said roughening process, 30-90 g / L permanganic acid or a permanganate solution and a 30-90 g / L sodium hydroxide solution are used, for example, process temperature 30-85 degreeC and 1-30 minutes. A method of treating a cured product under conditions is preferable. It is preferable that the temperature of the said roughening process exists in the range of 50-85 degreeC. The number of times of the roughening treatment is preferably once or twice.

  The arithmetic average roughness Ra of the surface of the cured product is preferably 50 nm or more, and preferably 350 nm or less. In this case, the adhesive strength between the cured product and the metal layer or wiring is increased, and further finer wiring is formed on the surface of the insulating layer.

(Desmear treatment)
A through-hole may be formed in the hardened | cured material obtained by precuring the said epoxy resin material. In the multilayer substrate or the like, a via or a through hole is formed as a through hole. For example, the via can be formed by irradiation with a laser such as a CO ₂ laser. The diameter of the via is not particularly limited, but is about 60 to 80 μm. Due to the formation of the through hole, a smear, which is a resin residue derived from the resin component contained in the cured product, is often formed at the bottom of the via.

  In order to remove the smear, the surface of the cured product is desmeared. The desmear process may also serve as a roughening process.

  In the desmear treatment, for example, a chemical oxidant such as a manganese compound, a chromium compound, or a persulfate compound is used in the same manner as the roughening treatment. These chemical oxidizers are used as an aqueous solution or an organic solvent dispersion after water or an organic solvent is added. The desmear treatment liquid used for the desmear treatment generally contains an alkali. The desmear treatment liquid preferably contains sodium hydroxide.

  The method for the desmear treatment is not particularly limited. As a method for the desmear treatment, for example, using a 30 to 90 g / L permanganate or permanganate solution and a 30 to 90 g / L sodium hydroxide solution, a treatment temperature of 30 to 85 ° C. and a condition of 1 to 30 minutes And the method of processing hardened | cured material once or twice is suitable. It is preferable that the temperature of the said desmear process exists in the range of 50-85 degreeC.

  By using the epoxy resin material, smear can be effectively removed, and the surface roughness of the desmeared cured product is sufficiently reduced.

  Hereinafter, the present invention will be specifically described by giving examples and comparative examples. The present invention is not limited to the following examples.

  The following ingredients were used.

(Epoxy resin)
Epoxy resin (1) (biphenyl type epoxy resin (“NC3000-FH-75M” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 315)
Epoxy resin (2) (biphenyl type epoxy resin (“NC3000” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 276)
Epoxy resin (3) (Bis A type epoxy resin, Nippon Kayaku Co., Ltd. “RE-410S”, epoxy equivalent 178)
Epoxy resin (4) (triazine ring epoxy resin, “TEPIC-SP” manufactured by Nissan Chemical Industries, epoxy equivalent 100)
Epoxy resin (5) (p-aminophenol type liquid epoxy resin, “630” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 96)

(Curing agent)
Active ester compound (1) (diphthalate esterified product of dicyclopentadiene skeleton, “HPC8000-65T” manufactured by DIC Corporation, active ester group equivalent 223)
Active ester compound (2) (Naphthalene skeleton-type active ester, "EXB-9416-70BK" manufactured by DIC, active ester group equivalent 330)
Phenol compound (aminotriazine novolac skeleton type phenol compound, “LA1356” manufactured by DIC, phenol group equivalent 146)

(Curing accelerator)
Imidazole compound (2-phenyl-4-methylimidazole, “2P4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.)

(Inorganic filler)
Silica-containing slurry (Silica 70 wt%: “SO-C2” manufactured by Admatechs, average particle size 0.5 μm, aminosilane treatment, cyclohexanone 30 wt%)

(Thermoplastic resin)
Phenoxy resin (solid content 30% by weight: “YX6954BH30” manufactured by Mitsubishi Chemical Corporation)

Example 1
50 parts by weight of the epoxy resin (1), 40 parts by weight of the epoxy resin (2), 5 parts by weight of the epoxy resin (4), 5 parts by weight of the epoxy resin (5), and 200 parts by weight of the active ester compound (2) Then, 7.2 parts by weight of the imidazole compound and 11.9 parts by weight of the phenoxy resin were put into 669 parts by weight of the silica-containing slurry, and stirred at 1200 rpm for 1 hour using a stirrer to obtain a resin composition. .

  On the release-treated surface of the release-treated transparent polyethylene terephthalate (PET) film (“PET5011 550” manufactured by Lintec Corporation, thickness 50 μm) using an applicator, the resulting resin composition has a thickness after drying of 40 μm. And dried in a gear oven at 100 ° C. for 1 minute to prepare an uncured resin film having a length of 200 mm × width of 200 mm × thickness of 40 μm.

(Examples 2-5 and Comparative Examples 1-9)
A resin composition and an uncured product of a resin film were prepared in the same manner as in Example 1 except that the type and the amount (parts by weight) of the components used were changed as shown in Table 1 below.

(Production of Evaluation Sample 1)
Lamination and semi-curing treatment:
The uncured product of the obtained resin film was vacuum-laminated on a CCL substrate (“E679FG” manufactured by Hitachi Chemical Co., Ltd.) and heated at 180 ° C. for 30 minutes to be semi-cured. Thus, the laminated body A by which the semi-cured material of the resin film was laminated | stacked on the CCL board | substrate was obtained.

Via (through hole) formation:
Using a CO ₂ laser (manufactured by Hitachi Via Mechanics Co., Ltd.) to the uncured product of the resin film of the obtained laminate A, a via having a diameter of 60 μm at the upper end and a diameter of 40 μm at the lower end (bottom) (through) Hole) was formed. Thus, the laminated body B by which the semi-cured material of the resin film was laminated | stacked on the CCL board | substrate, and the via | veer (through-hole) was formed in the semi-cured material of the resin film was obtained.

Removal of residue at the bottom of the via:
(A) Swelling treatment The obtained laminate B was placed in a swelling liquid at 80 ° C. (“Swelling dip securigant P” manufactured by Atotech Japan Co., Ltd.) and rocked for 10 minutes. Thereafter, it was washed with pure water.

(B) Permanganate treatment (roughening treatment and desmear treatment)
The layered product B after the swelling treatment was put into a roughened aqueous solution of potassium permanganate (“Concentrate Compact CP” manufactured by Atotech Japan Co., Ltd.) at 80 ° C. and rocked for 20 minutes. Next, it was treated for 2 minutes using a 25 ° C. cleaning solution (“Reduction Securigant P” manufactured by Atotech Japan), and then washed with pure water.

(Preparation of evaluation sample 2)
The uncured product of the obtained resin film was heated at 180 ° C. for 90 minutes to obtain a cured product.

(Evaluation)
(1) Distribution state of epoxy resin having the lowest epoxy equivalent Uncured resin film obtained was dissolved in cyclohexanone, and silica was separated by centrifugation to obtain a resin composition. Except having used the obtained resin composition, it carried out similarly to the Example and the comparative example, produced the uncured material of the resin film, and obtained the laminated body A. The uncured product of the resin film not containing silica was different from the uncured product of the resin composition containing silica only in the presence or absence of silica. The surface and cross section of the laminate A obtained by using an uncured resin film containing no silica were measured by energy dispersive X-ray analysis (EDX). In the laminate A, it was confirmed whether or not the epoxy resin having the lowest epoxy equivalent was uniformly dispersed in the semi-cured product. The dispersion state of the epoxy resin having the lowest epoxy equivalent in the semi-cured product corresponds to the dispersion state of the epoxy resin having the lowest epoxy equivalent in the uncured product of the resin film.

[Criteria for dispersion state of epoxy resin with the lowest epoxy equivalent]
○: The epoxy resin having the lowest epoxy equivalent is uniformly dispersed (the area of the region where the epoxy resin having the lowest epoxy equivalent does not exist is less than 10 μm ² ).
X: The epoxy resin with the lowest epoxy equivalent is dispersed non-uniformly (the area of the region where the epoxy resin with the lowest epoxy equivalent does not exist is 10 μm ² or more)

(2) Measurement of dielectric loss tangent Evaluation sample 2 was cut into a size of 2 mm in width and 80 mm in length, and 10 sheets were laminated to form a laminate having a thickness of 400 μm. The dielectric loss tangent was measured at a measurement frequency of 1 GHz at room temperature (23 ° C.) by a cavity resonance method using a ratio measuring device CP521 ”and“ Network Analyzer E 8362B ”manufactured by Agilent Technologies. The dielectric loss tangent was determined according to the following criteria.

[Criteria for dielectric loss tangent]
○: Dielectric tangent is less than 0.005 Δ: Dielectric tangent is 0.005 or more and less than 0.006 ×: Dielectric tangent is 0.006 or more

(3) Evaluation of Removability of Via Bottom Residue The bottom of the via of Evaluation Sample 1 was observed with a scanning electron microscope (SEM), and the maximum length of smear from the wall surface of the via bottom was measured. The removability of the residue at the bottom of the via was determined according to the following criteria.

[Judgment criteria for removal of via bottom residue]
○: Maximum smear length is less than 3 μm △: Maximum smear length is not less than 3 μm and less than 5 μm ×: Maximum smear length is not less than 5 μm

  The composition and results are shown in Table 1 below. Note that “−” indicates that evaluation is not performed.

DESCRIPTION OF SYMBOLS 11 ... Multilayer substrate 12 ... Circuit board 12a ... Upper surface 13-16 ... Insulating layer 17 ... Metal layer (wiring)

Claims (6)

Including two or more epoxy resins, an active ester compound, a curing accelerator, and an inorganic filler;
The ratio of the epoxy equivalent of the two or more epoxy resins to the active ester group equivalent of the active ester compound is 1: 0.8 to 1: 1.2;
The standard deviation σ of the epoxy equivalent determined by the following formula (1) of the two or more epoxy resins is 1/3 or more of the average epoxy equivalent m determined by the following formula (2) of the two or more epoxy resins. There is an epoxy resin material.
Standard deviation of epoxy equivalent σ = [{(m ₁ −m) ² + (m ₂ −m) ² +... + (M _n −m) ² } / (w ₁ / m ₁ + w ₂ / m ₂ + ... + w _n / m _n )] ^1/2 ... Formula (1)
Average epoxy equivalent m = (w ₁ + w ₂ +... + W _n ) / (w ₁ / m ₁ + w ₂ / m ₂ +... + W _n / m _n ) (2)
m ₁ : Epoxy equivalent of the first type epoxy resin m ₂ : Epoxy equivalent of the second type epoxy resin m _n : Epoxy equivalent of the nth type epoxy resin w ₁ : Solid weight of the first type epoxy resin w _2: 2 solids weight type eye epoxy resin w _n: solid weight of _n type second epoxy resin   The epoxy resin material according to claim 1, wherein an epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is uniformly dispersed in the epoxy resin material.   The epoxy resin material according to claim 1 or 2, wherein an epoxy equivalent of an epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is 130 or less.   The epoxy resin material according to any one of claims 1 to 3, wherein the epoxy resin having the lowest epoxy equivalent among the two or more types of epoxy resins is an epoxy resin containing a nitrogen atom.   The epoxy resin material according to claim 1, wherein the epoxy resin material is a B-stage film formed into a film shape. A circuit board;
An insulating layer disposed on the circuit board,
The multilayer substrate in which the said insulating layer is formed by hardening the epoxy resin material of any one of Claims 1-5.

Images