JP2011126963A - Resin sheet, printed-wiring board and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sheet which excels in handling properties and flowability on molding and makes a resin layer having a low linear expansion coefficient and a low water absorption, a printed-wiring board using the resin sheet which can form a thin and fine wiring circuit having excellent reliability, and furthermore a semiconductor device using the printed-wiring board having excellent reliability. <P>SOLUTION: The resin sheet is obtained by forming a resin layer composed of a resin composition having (A) a dicyclopentadiene type cyanate resin, (B) an epoxy resin, and (C) an inorganic filler as essential components on a base material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a resin sheet, a printed wiring board, and a semiconductor device.

In recent electronic devices, higher-speed transmission and higher-density integration are progressing, and a build-up type printed wiring board is often used as a printed wiring board used in these electronic devices.

  In addition, the printed wiring board has been densely integrated and thinned, but there is a problem that the strength is reduced by making the printed wiring board thinner. In order to solve the above problems, studies have been made to use a prepreg obtained by impregnating a glass cloth with a resin composition using a thermosetting resin for an insulating resin layer of a printed wiring board (Patent Documents 1 and 2). However, when the prepreg is thinned, the resin thickness on the prepreg is not uniform at the time of lamination, and flatness cannot be maintained. In addition, there are problems that it is difficult to reduce the via diameter by laser irradiation, and that the reliability of connection between insulating layers is lowered due to insufficient laser opening. Therefore, with the demand for further thinning and high density of the printed wiring board, it is easy to handle and mold without using a prepreg impregnated in glass cloth etc. In addition to the multilayer printed wiring board, When used as an insulating layer, there is a need for an insulating resin sheet that has high strength and excellent connection reliability between insulating layers, and when used in a semiconductor device, has low warpage and excellent mounting reliability.

JP 2002-305374 A JP 2003-73543 A

    An object of the present invention is to provide a resin sheet that is excellent in handling properties and fluidity at the time of molding, and serves as a low water absorption insulating layer with low linear thermal expansion. Another object of the present invention is to provide a thin and excellent printed wiring board capable of forming a fine wiring circuit using the resin sheet of the present invention, and a semiconductor device having excellent reliability using the printed wiring board. .

Such an object is achieved by the present invention described in the following [1] to [9].
[1] An insulating resin layer comprising a resin composition containing (A) a dicyclopentadiene-type cyanate resin, (B) an epoxy resin, and (C) an inorganic filler as essential components, is formed on a substrate. Characteristic resin sheet.
[2] The resin sheet according to item [1], wherein the (A) dicyclopentadiene-type cyanate resin is 5 to 60% by weight of the entire resin composition.
[3] The resin sheet according to [1] or [2], wherein the (B) epoxy resin is an aryl alkylene type epoxy resin.
[4] The resin sheet according to any one of [1] to [3], wherein the (C) inorganic filler is an inorganic filler having an average particle diameter of 0.01 to 5 μm.
[5] The inorganic filler (C) is at least one inorganic filler selected from the group consisting of spherical silica, calcined talc and monohydrated alumina, [1] to [4] Resin sheet.
[6] The resin sheet according to any one of [1] to [5], wherein the (C) inorganic filler is 30 to 80% by weight of the entire resin composition.
[7] A printed wiring board formed by heating and press-molding the resin sheet according to any one of [1] to [6] on one or both surfaces of the inner circuit board,
[8] The resin sheet according to any one of [1] to [7] is overlaid on one or both surfaces of the inner circuit board and heat-press molded, and then includes desmear, electroless plating, and electrolytic plating processes. A printed wiring board having a circuit formed using a circuit forming process;
[9] A semiconductor device in which a semiconductor element is mounted on the printed wiring board according to [7] or [8].

The resin sheet of the present invention is easy to handle and moldability, and when used as an insulating layer of a printed wiring board, it has high strength and excellent connection reliability between insulating layers, and is used for a semiconductor device. In this case, the warpage is small, and the insulating property is excellent in mounting reliability.

Hereinafter, the resin sheet, the printed wiring board, and the semiconductor device of the present invention will be described in detail.

  First, the resin sheet of this invention is demonstrated.

  The resin composition forming the resin layer of the resin sheet of the present invention includes (A) a dicyclopentadiene type cyanate resin (hereinafter sometimes referred to as (A) a DCPD type cyanate resin), (B) an epoxy resin, and (C) An inorganic filler is an essential component.

The (A) DCPD type cyanate resin is not particularly limited, and can be obtained, for example, by reacting a halogenated cyanide compound with a dicyclopentadiene type phenol and, if necessary, by a method such as heating. By using a DCPD type cyanate resin, a cured product having a low linear expansion coefficient due to a triazine ring cross-linked structure, a low water absorption rate derived from a molecular skeleton, and excellent dielectric properties can be obtained after curing. Moreover, moisture absorption heat resistance is also improved by low water absorption. (A) As DCPD type cyanate resin, what is shown, for example by Formula (I) can be used.

  Although n of the DCPD type cyanate resin represented by the formula (I) is not particularly limited, 1 to 10 is preferable, and 1 to 7 is particularly preferable. If the amount is less than this, the DCPD type cyanate resin is easily crystallized, and the solubility in a general-purpose solvent is relatively lowered, which may make handling difficult. On the other hand, if the amount is larger than this, the crosslink density becomes too high, which may cause a phenomenon such as a decrease in water absorption and a cured product becoming brittle.

The weight average molecular weight of the (A) DCPD type cyanate resin is not particularly limited, but is preferably 5.0 × 10 ^{2 to} 4.5 × 10 ³ , particularly 6.0 × 10 ^{2 to} 3.0 ×. 10 ³ is preferred. If it is smaller than the lower limit, tackiness may occur when a resin sheet is produced, and a bleed phenomenon may occur when the resin sheet is produced in the form of a continuous roll. On the other hand, when the value is larger than the upper limit, the reaction becomes too fast, and molding failure may occur, or when used for a printed wiring board, the interlayer peel strength between the resin layer and the resin layer may be lowered.

The (A) DCPD type cyanate resin may be a prepolymerized one. That is, (A) DCPD type cyanate resin may be used alone, cyanate resins having different weight average molecular weights may be used in combination, or (A) DCPD type cyanate resin and its prepolymer may be used in combination. .
Here, the prepolymer is usually obtained by, for example, trimerizing the cyanate resin by a heat reaction or the like, and is preferably used for adjusting the moldability and fluidity of the epoxy resin composition. It is. Although a prepolymer is not specifically limited, For example, it is preferable to use what a trimerization rate is 20 to 50 weight%. This trimerization rate can be determined using, for example, an infrared spectroscopic analyzer. Alternatively, it can be used in combination with other cyanate resins having different molecular skeletons. Examples of the other cyanate resins include novolac type cyanate resins, bisphenol A type cyanate resins, bisphenol E type cyanate resins, and bisphenol type cyanate resins such as tetramethyl bisphenol F type cyanate resins.

  Although content of said (A) DCPD type cyanate resin is not specifically limited, 5 to 60 weight% of the whole resin composition is preferable, and 10 to 50 weight% is especially preferable. If the DCPD-type cyanate resin and / or its prepolymer is less than the lower limit, the heat resistance and the effect of low thermal expansion may be reduced, and if the upper limit is exceeded, the crosslinking density increases and the free volume increases, resulting in moisture resistance. May decrease.

  In addition to (A) DCPD type cyanate resin, the resin composition may be used in combination with a cyanate resin. Among them, it is preferable to use a bisphenol type cyanate resin such as a novolac type cyanate resin, a bisphenol A type cyanate resin, a bisphenol E type cyanate resin, or a tetramethylbisphenol F type cyanate resin.

  The resin composition for forming the resin layer of the resin sheet of the present invention comprises (B) an epoxy resin as an essential component. The (B) epoxy resin is not particularly limited, and examples thereof include a phenol novolac type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, and an arylalkylene type epoxy resin. Among these, aryl alkylene type epoxy resins and naphthalene-modified phenol novolac type epoxy resins are preferable. Thereby, moisture resistance can be improved. The arylalkylene-type epoxy resin refers to an epoxy resin having one or more arylalkylene groups in a repeating unit. For example, a xylylene type epoxy resin, a biphenyl dimethylene type epoxy resin, etc. are mentioned. Among these, a biphenyl dimethylene type epoxy resin is preferable. A biphenyl dimethylene type | mold epoxy resin can be shown, for example by Formula (II). The naphthalene-modified phenol novolac type epoxy resin can be represented by, for example, the formula (III).

Although n of the biphenyl dimethylene type | mold epoxy resin shown by the said formula (II) is not specifically limited, 1-10 are preferable and 2-5 are especially preferable. If it is less than this, the biphenyl dimethylene type epoxy resin will be easily crystallized, and the solubility in general-purpose solvents will be relatively lowered, which may make handling difficult. Moreover, when more than this, the fluidity | liquidity of resin will fall and it may become a cause of a molding defect. (A) A resin sheet using a resin composition comprising a DCPD type cyanate resin and an arylalkylene type epoxy resin (particularly a biphenyldimethylene type epoxy resin) or a naphthalene-modified phenol novolac type epoxy resin represented by the formula (III) When produced, it has low water absorption and can achieve low water absorption even in the pressure cooker test (PCT).

Although the weight average molecular weight of the (B) epoxy resin is not particularly limited, the weight average molecular weight is preferably 5.0 × 10 ^{2 to} 2.0 × 10 ⁴ , particularly 8.0 × 10 ^{2 to} 1.5 × 10 ^4. Is preferred. When the weight average molecular weight is smaller than the lower limit, tackiness occurs when a resin sheet is produced, and workability is reduced. Moreover, when a resin sheet is produced in a continuous roll shape, a bleed phenomenon may occur. If it is larger than the upper limit, the melt viscosity becomes high and molding failure may occur, or when used for a printed wiring board, the interlayer peel strength between the insulating layer and the insulating layer may be lowered.

  Although content of the said (B) epoxy resin is not specifically limited, 1 to 55 weight% of the whole resin composition is preferable, and 2 to 40 weight% is especially preferable. If the resin is less than the lower limit, the reactivity of the cyanate resin may be reduced, or the moisture resistance of the resulting product may be reduced. If the resin exceeds the upper limit, the heat resistance may be reduced.

  The resin composition forming the resin layer of the resin sheet of the present invention contains (C) an inorganic filler as an essential component. The (C) inorganic filler is not particularly limited, and examples thereof include talc, alumina, glass, silica, boehmite, and mica. Thereby, low thermal expansion and improvement in flame retardancy are achieved. Moreover, the elasticity modulus of a resin layer can be made high by the combination of (A) DCPD type cyanate resin and (C) inorganic filler mentioned above. (C) Silica is preferable as the inorganic filler, and fused silica is excellent in that it has a low coefficient of thermal expansion. On the other hand, talc and monohydrated alumina are preferable in that they do not decompose to high temperatures and are excellent in flame retardancy.

  The shape of the (C) inorganic filler is not particularly limited, and examples thereof include a crushed shape, a plate shape, and a spherical shape. In order to reduce the melt viscosity of the resin composition in order to ensure fluidity during molding, it is preferable to use a spherical inorganic filler. The shape can be selected according to its purpose, application, and performance.

  The average particle diameter of the (C) inorganic filler is not particularly limited, but is preferably 0.01 to 5 μm, particularly preferably 0.2 to 2 μm. If the particle size of the inorganic filler is smaller than the lower limit, the viscosity of the varnish becomes high, which may affect the workability at the time of preparing the prepreg. Moreover, when larger than the said upper limit, phenomena, such as sedimentation of an inorganic filler, may occur in a varnish.

  The content of the (C) inorganic filler is preferably 30 to 80% by weight, particularly preferably 40 to 70% by weight, based on the entire resin composition. When the inorganic filler is within the above range, it has low thermal expansion, and can satisfy all of high flame retardancy and high heat resistance.

  Although the resin composition which forms the resin layer of the resin sheet of this invention is not specifically limited, A phenol resin can further be used as a resin component. Although it does not specifically limit as a phenol resin, A novolak type phenol resin, a resol type phenol resin, an aryl alkylene type phenol resin, etc. are mentioned.

  The resin composition forming the resin layer of the resin sheet of the present invention may contain a film-forming resin. When a film-forming resin is used, it is preferable in terms of further improving the film-forming property and handling property when a resin sheet is manufactured.

  The film-forming resin is not particularly limited. For example, other thermosetting resins such as phenoxy resin, bisphenol F resin, olefin resin, vinyl ester resin, melamine resin, phenoxy resin, polyimide resin, polyamide Examples thereof include imide resins, polyphenylene oxide resins, and polyethersulfone resins. As the film-forming resin, one kind including derivatives thereof can be used alone, or two or more kinds having different weight average molecular weights can be used in combination, or one kind or two kinds or more can be used together. A polymer can also be used in combination. Among these, a phenoxy resin is preferable. Thereby, heat resistance and a flame retardance can be improved.

The phenoxy resin is not particularly limited. For example, the phenoxy resin has a bisphenol A skeleton, a phenoxy resin having a bisphenol F skeleton, a phenoxy resin having a bisphenol S skeleton, a phenoxy resin having a bisphenol M skeleton, and a bisphenol P skeleton. Phenoxy resin, phenoxy resin having bisphenol Z skeleton, etc. Having a phenoxy resin having a naphthalene skeleton, a phenoxy resin having a biphenyl skeleton, an adamantane skeleton Phenoxy resins.
Further, as the phenoxy resin, a structure having a plurality of types of skeletons can be used, and phenoxy resins having different ratios of the skeletons can be used. Furthermore, a plurality of types of phenoxy resins having different skeletons can be used, a plurality of types of phenoxy resins having different weight average molecular weights can be used, or prepolymers thereof can be used in combination.

Among these, a phenoxy resin having a biphenyl skeleton and a bisphenol S skeleton can be used. Thereby, the glass transition temperature can be increased due to the rigidity of the biphenyl skeleton, and the adhesion of the plated metal when the multilayer printed wiring board is manufactured can be improved by the bisphenol S skeleton.
Alternatively, a phenoxy resin having a bisphenol A skeleton and a bisphenol F skeleton can be used. Thereby, the adhesiveness to an inner-layer circuit board can be improved at the time of manufacture of a multilayer printed wiring board. Further, the phenoxy resin having the biphenyl skeleton and the bisphenol S skeleton and the phenoxy resin having the bisphenol A skeleton and the bisphenol F skeleton may be used in combination.

Although it does not specifically limit as molecular weight of the said film forming resin, It is preferable that a weight average molecular weight is 1.0 * 10 < ³ > -1.0 * 10 < ⁵ >. More preferably from ^{1.0 × 10 4 ~6.0 × 10 4} . If the weight average molecular weight of the film forming resin is less than the lower limit, the effect of improving the film forming property may not be sufficient. On the other hand, when the above upper limit is exceeded, the solubility of the film-forming resin may decrease. By making the weight average molecular weight of the film-forming resin within the above range, it is possible to achieve an excellent balance of these characteristics.

  Although it does not specifically limit as content of film forming resin, It is preferable that it is 1 to 30 weight% of the whole resin composition. More preferably, it is 4 to 20% by weight. If the content of the film-forming resin is less than the lower limit, the effect of improving the film-forming property may not be sufficient. On the other hand, when the above upper limit is exceeded, the content of the cyanate resin is relatively reduced, and thus the effect of imparting low thermal expansion may be reduced. By setting the content of the film-forming resin within the above range, it is possible to achieve an excellent balance of these characteristics.

  The resin composition can further use a coupling agent. The coupling agent has a uniform resin composition with respect to the substrate by improving the wettability of the interface between (A) DCPD type cyanate resin and / or (B) epoxy resin resin and (C) inorganic filler. A resin layer made of a material can be fixed. Any coupling agent can be used as long as it is usually used. Among these, at least one selected from an epoxy silane coupling agent, a titanate coupling agent, an aminosilane coupling agent, and a silicone oil type coupling agent. Use of a coupling agent is preferable in terms of high wettability with the inorganic filler interface and improvement in heat resistance. Of these, aminosilane coupling agents are particularly excellent in heat resistance after moisture absorption.

  The coupling agent is preferably 0.05% by weight or more and 3% by weight or less based on (C) the inorganic filler. If the amount is less than this, the filler may not be sufficiently coated and sufficient heat resistance may not be obtained. If the amount is more than this, the reaction will be affected, and the bending strength will decrease. preferable.

  The resin composition may use a curing accelerator as necessary. A well-known thing can be used as a hardening accelerator. Although not particularly limited, for example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), trisacetylacetonate cobalt (III), triethylamine, tributylamine , Tertiary amines such as diazabicyclo [2,2,2] octane, 2-phenyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4- Imidazoles such as methyl-5-hydroxyimidazole, 2-phenyl-4,5-dihydroxyimidazole, phenolic compounds such as phenol, bisphenol A, nonylpheno, organic acids such as acetic acid, benzoic acid, salicylic acid, paratoluenesulfonic acid, etc. Or this mixed And the like.

  If necessary, the resin composition forming the resin layer of the resin sheet of the present invention may contain additives other than the above components as long as the properties are not impaired.

  The resin sheet of this invention is obtained by forming the resin layer which consists of the said resin composition on a base material. First, in order to form a resin layer, first, the resin composition is made of acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, ethyl acetate, cyclohexane, heptane, cyclohexane cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol. In various organic solvents such as cellosolve, carbitol, and anisole, various mixing methods such as ultrasonic dispersion method, high-pressure collision dispersion method, high-speed rotation dispersion method, bead mill method, high-speed shear dispersion method, and rotation and revolution dispersion method A resin varnish is prepared by dissolving, mixing, and stirring using a machine.

  Although content of the resin composition in the said resin varnish is not specifically limited, 45 to 85 weight% is preferable and 55 to 75 weight% is especially preferable.

  Next, the resin varnish is coated on a supporting substrate using various coating apparatuses, and then dried to produce a resin sheet. Although a base material is not specifically limited, For example, a film or metal foil can be used.

  Although it does not specifically limit as a film, In order to form a resin layer on a film, it is preferable to select what is easy to handle. Moreover, since a film is peeled after laminating | stacking the resin layer of a resin sheet on the inner layer circuit board surface, it is preferable that peeling is easy after laminating | stacking on an inner layer circuit board.

  As the film, for example, a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, or a thermoplastic resin film having heat resistance such as a fluorine resin or a polyimide resin is preferably used. Among these substrates, a film composed of polyester is most preferable. This facilitates peeling from the resin layer with an appropriate strength.

  Although the thickness of the said film is not specifically limited, 1-100 micrometers is preferable and 3-50 micrometers is especially preferable. When the thickness of the film is within the above range, handling is easy and the flatness of the surface of the insulating layer is excellent.

  Similar to the film, the metal foil may be used after being peeled off after laminating a resin sheet on the inner circuit board, or may be used by etching the metal foil as a conductor circuit.

  The metal foil is not particularly limited. For example, copper and / or copper-based alloy, aluminum and / or aluminum-based alloy, iron and / or iron-based alloy, silver and / or silver-based alloy, gold and gold-based alloy, Metal foils such as zinc and zinc alloys, nickel and nickel alloys, tin and tin alloys can be used.

The metal foil may be an ultrathin metal foil with a carrier foil. The ultrathin metal foil with a carrier foil is a metal foil obtained by laminating a peelable carrier foil and an ultrathin metal foil. Since an ultrathin metal foil layer can be formed on both sides of the resin layer by using an ultrathin metal foil with a carrier foil, for example, when forming a circuit by a semi-additive method, etc. By electroplating the metal foil directly as a power feeding layer, the ultrathin copper foil can be flash etched after the circuit is formed. By using an ultra-thin metal foil with a carrier foil, even with an ultra-thin metal foil having a thickness of 10 μm or less, for example, a reduction in handling properties of the ultra-thin metal foil in a pressing process, and cracking or cutting of the ultra-thin copper foil are prevented. Can do. The thickness of the ultrathin metal foil is preferably 1 μm or more and 10 μm or less. Further, it is preferably 1 μm or more and 5 μm or less, more preferably 1 μm or more and 3 μm or less. When the thickness of the ultrathin metal foil is less than the lower limit, the ultrathin metal foil is damaged after peeling the carrier foil, the pinhole of the ultrathin metal foil is generated, and the circuit pattern is formed by the generation of the pinhole. Plating variation, disconnection of circuit wiring, penetration of chemicals such as etching liquid and desmear liquid, etc. may occur. If the above upper limit is exceeded, the thickness variation of the ultrathin metal foil will increase or the ultrathin metal foil There may be a case where the roughness of the roughened surface becomes large. Usually, an ultrathin metal foil with a carrier foil peels off the carrier foil before forming a circuit pattern on the press-molded laminate.

  Although the said coating apparatus is not specifically limited, For example, a roll coater, a bar coater, a knife coater, a gravure coater, a die coater, a comma coater, a curtain coater, etc. can be used. Among these, a method using a die coater, a knife coater, and a comma coater is preferable. Thereby, the resin sheet which does not have a void and has the thickness of the uniform resin layer can be manufactured efficiently.

Next, although an example is demonstrated about a printed wiring board, it is not specifically limited, A printed wiring board can be obtained with the manufacturing method of a well-known printed wiring board.
In addition, when a printed wiring board is manufactured by the buildup method using the resin sheet of the present invention, the printed wiring board can be manufactured with a high yield, and the obtained printed wiring board is excellent in reliability.

Hereinafter, an example of a method for manufacturing a printed wiring board by a build-up method will be described.

  First, a laminate having metal foil on both sides (for example, a copper-clad laminate) is prepared, through holes are formed by drilling, laser processing, etc., and after filling the through holes by plating, on both sides of the laminate, A predetermined conductor circuit (inner layer circuit) is formed by etching or the like, and the inner layer circuit board is manufactured by subjecting the conductor circuit to a roughening process such as a blackening process.

Next, the above-described resin sheet is formed on the upper and lower surfaces of the inner layer circuit board, and is heated and pressed.
Specifically, the resin sheet and the inner circuit board are combined and subjected to vacuum heating and pressure molding using a vacuum pressure laminator device or the like. Thereafter, the resin layer can be formed on the inner circuit board by heating and curing with a hot air drying device or the like.
Here, the conditions for heat and pressure molding are not particularly limited, but for example, it can be carried out at a temperature of 60 to 160 ° C. and a pressure of 0.2 to 3 MPa. Moreover, it is although it does not specifically limit as conditions to heat-harden, If an example is given, it can implement in temperature 140-240 degreeC and time 30-120 minutes.

As another method, the resin sheet can be formed on the inner circuit board by superimposing the resin sheet on the inner circuit board and performing heat-pressure molding using a flat plate press or the like.
Here, the conditions for heat and pressure molding are not particularly limited, but for example, it can be carried out at a temperature of 140 to 240 ° C. and a pressure of 1 to 4 MPa.

  Thereafter, the resin layer is cured by heating. Although the temperature to harden | cure is not specifically limited, If an example is given, it can be hardened in the range of 100 to 250 degreeC. Preferably it is made to harden | cure at 150 to 230 degreeC.

Next, an opening is formed in the resin layer using a laser device, and after removing smear from the bottom of the laser opening and roughening the resin surface with an oxidizing agent such as permanganate or dichromate, metal plating is performed. Thus, a new conductive wiring circuit can be formed. For example, the outer layer circuit and the inner layer circuit are electrically connected by filling the laser opening with metal by electrolytic copper plating or by performing metal plating on the wall surface of the opening. At the same time, an outer layer circuit is formed on the surface resin layer surface to provide a connection electrode portion for mounting a semiconductor element. For the circuit formation method, a generally known semi-additive process can be used. As the laser, an excimer laser, a UV laser, a carbon dioxide laser, or the like can be used.
Incidentally, after the outer layer circuit is formed, heat treatment may be performed in order to further advance the curing.

  After that, a solder resist is formed on the outermost layer, the connection electrode part is exposed so that a semiconductor element can be mounted by exposure and development, nickel gold plating treatment is performed, and a printed wiring board is obtained by cutting to a predetermined size. it can. The method for forming the solder resist is not particularly limited, but for example, by laminating a dry film type solder resist and forming it by exposure and development, or by forming a liquid resist printed by exposure and development Made.

Next, a semiconductor device will be described.
A semiconductor device can be manufactured by mounting a semiconductor element on a printed wiring board manufactured by the method described above. The mounting method and the sealing method of the semiconductor element are not particularly limited. For example, a semiconductor element and a printed wiring board are used, and a flip-chip bonder or the like is used to align the connection electrode portions on the printed wiring board and the solder bumps of the semiconductor element. Thereafter, the solder bump is heated to the melting point or higher by using an IR reflow device, a hot plate, or other heating device, and the printed wiring board and the solder bump are connected by fusion bonding. And a semiconductor device can be obtained by filling and hardening a liquid sealing resin between a printed wiring board and a semiconductor element.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  Examples of the resin sheet, printed wiring board, and semiconductor device of the present invention and comparative examples will be described below, but the present invention is not limited thereto.

Example 1
1. Manufacture of resin varnish (A) 13.5 parts by weight of dicyclopentadiene type cyanate resin (Lonza Japan, Primaset DT-4000), (B) methoxynaphthalenediethylene-modified phenol novolac epoxy resin (manufactured by DIC) EXA-7320L, epoxy equivalent 246) 22.5 parts by weight, (C) 54.5 parts by weight of spherical silica (manufactured by Admatechs, SO-25R, average particle size 0.5 μm) as an inorganic filler, as a curing accelerator 0.2 part by weight of 1-benzyl-2-phenylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., Curazole 1B2PZ), 30 parts by weight (solid) of phenoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., YX6954BH30, solid content 30% by weight) The amount is 9 parts by weight.) Compound and (GE Toshiba Silicone Co., Ltd., A-187) 0.3 parts by weight were dissolved and mixed in methyl isobutyl ketone, and cyclohexanone. Subsequently, it stirred for 60 minutes using the high-speed stirring apparatus, and prepared the resin varnish of about 65 weight% of solid content. In addition, the ratio of (C) inorganic filler in the resin composition was 55% by weight.

2. Production of Resin Sheet The resin varnish obtained above was dried on a single side of a 50 μm-thick polyethylene terephthalate film (Diafoil MRX-50, manufactured by Mitsubishi Polyester Film Co., Ltd.) using a comma coater device to a resin layer of 40 μm. Then, this was dried with a drying apparatus at 150 ° C. for 10 minutes to produce a resin sheet based on a polyethylene terephthalate film (PET film).

3. Manufacture of printed wiring board First, using a double-sided copper-clad laminate (ELC-4785GS manufactured by Sumitomo Bakelite Co., Ltd.) having a total thickness of 0.3 mm and a copper foil thickness of 18 μm, Conduction between the upper and lower copper foils was achieved by electrolytic plating, and the inner layer circuit was formed on both sides by etching the copper foils on both sides to obtain an inner layer circuit board. (Conductor circuit width (L) / inter-circuit width (S) = 120/180 μm, clearance holes 1 mmφ, 3 mmφ, slit 2 mm)

Next, the inner layer circuit board was sprayed with a chemical solution mainly composed of hydrogen peroxide and sulfuric acid (Tech SO-G manufactured by Asahi Denka Kogyo Co., Ltd.) to form irregularities by roughening treatment. Next, the resin sheet obtained above was laminated using a vacuum pressure laminator (manufactured by Meiki Seisakusho, MVLP-500 / 600IIA). The vacuum lamination zone was performed at 100 ° C. and 1 MPa, and the hot press zone was 100 ° C. and 1.0 MPa.
Next, the PET film of the resin sheet was peeled off, and the insulating resin layer was semi-cured by heating at a temperature of 170 ° C. for 60 minutes.

  Next, a φ60 μm opening (blind via hole) is formed using a carbonic acid laser device, immersed in a swelling liquid at 70 ° C. (Swelling Dip Securigant P, manufactured by Atotech Japan) for 10 minutes, and further at 80 ° C. After immersion for 20 minutes in an aqueous potassium permanganate solution (manufactured by Atotech Japan Co., Ltd., Concentrate Compact CP), it was neutralized and roughened. Next, after passing through degreasing, catalyst application, and activation steps, an electroless copper plating film was formed with a power supply layer of about 0.5 μm. Next, a 25 μm thick UV-sensitive dry film (AQ-2558 manufactured by Asahi Kasei Co., Ltd.) is bonded to the surface of the power supply layer with a hot roll laminator, and a chromium having a pattern with a minimum line width / line spacing of 20/20 μm is drawn. Using a vapor deposition mask (manufactured by Towa Process Co., Ltd.), the position was adjusted, exposure was performed with an exposure apparatus (UX-1100SM-AJN01 manufactured by USHIO INC.), And development was performed with a sodium carbonate aqueous solution to form a plating resist.

  Next, electrolytic copper plating (81-HL manufactured by Okuno Pharmaceutical Co., Ltd.) was performed at 3 A / dm 2 for 30 minutes using the power feeding layer as an electrode to form a copper wiring having a thickness of about 25 μm. Here, the plating resist was peeled off using a two-stage peeling machine. Each chemical solution is mainly composed of monoethanolamine solution (R-100 manufactured by Mitsubishi Gas Chemical Co., Ltd.) in the first stage alkaline aqueous solution layer, and potassium permanganate and sodium hydroxide as the main ingredients in the second stage oxidizing resin etchant. An aqueous solution of acidic amine (Mc. Dicer 9279, manufactured by Nihon McDermid Co., Ltd.) was used for neutralization.

  Next, the power feeding layer was immersed in an aqueous ammonium persulfate solution (AD-485 manufactured by Meltex Co., Ltd.) to remove it by etching and ensure insulation between the wirings. Next, the resin layer was finally cured at a temperature of 200 ° C. for 60 minutes, and finally a solder resist (PSR4000 / AUS308 manufactured by Taiyo Ink Co., Ltd.) was formed on the circuit surface to obtain a printed wiring board.

4). Manufacture of Semiconductor Device A semiconductor device was manufactured using the printed wiring board obtained above. Since the semiconductor element used in the semiconductor device has solder bumps, a printed wiring board used in advance was subjected to nickel gold plating on a circuit portion corresponding to the arrangement of the solder bumps. The printed wiring board used has a size of 50 mm × 50 mm.
In the semiconductor element (TEG chip, size 15 mm × 15 mm, thickness 0.8 mm), the solder bump is formed of a eutectic of Sn / Pb composition, and the circuit protective film is a positive photosensitive resin (CRC-8300 manufactured by Sumitomo Bakelite Co., Ltd.). What was formed in was used.

  In assembling the semiconductor device, first, a flux material was uniformly applied to the solder bumps by a transfer method, and then mounted on a printed wiring board by thermocompression bonding using a flip chip bonder device. Next, after solder bumps were melt-bonded in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured to obtain a semiconductor device. The curing condition of the liquid sealing resin was a temperature of 150 ° C. and 120 minutes.

(Examples 2 to 5 and Comparative Example 1)
In Examples 2 to 5 and Comparative Example 1, resin varnishes were produced in the same manner as in Example 1 with the formulation shown in Table 1, and resin sheets, printed wiring boards, and semiconductor devices were obtained.
In Example 3, 30 parts by weight (solid content is 9 parts by weight) of YX-8100H30 (manufactured by Japan Epoxy Resin Co., Ltd., solid content of 30% by weight) was used as the phenoxy resin instead of YX-6654BH30. In Examples 4 and 5, and Comparative Example 1, a copper foil (manufactured by Nippon Electrolytic Co., Ltd., YSNAP-3B (3 μm, ultrathin foil with carrier)) was used in place of the base PET film.
The composition in the table is a solid content ratio.

  Table 1 shows the evaluation items and evaluation results of the resin varnish blends, the examples, and the resin sheets, multilayer printed wiring boards, and semiconductor devices obtained in the comparative examples.

The above evaluation was performed by the following method.

<(1) Glass transition temperature>
The support base material was removed from the resin sheet obtained above, and then a resin plate heated and cured at 200 ° C. for 1 hour with a dryer under a nitrogen atmosphere was used as a sample. Using a dynamic viscoelastic device (TA Instruments), tensile measurement was performed at a frequency of 10 Hz, a heating rate of 5 ° C./min, and a temperature of 25 to 350 ° C. in a nitrogen atmosphere. The glass transition temperature was a temperature at which the tan δ value obtained by the measurement showed a maximum value.

<(2) Linear thermal expansion coefficient>
The support base material was removed from the resin sheet obtained above, and then a resin plate heated and cured at 200 ° C. for 1 hour with a dryer under a nitrogen atmosphere was used as a sample. Using a thermomechanical measuring apparatus (TA Instruments Co., Ltd.), a temperature increase rate of 10 ° C./min, a temperature of 25 to 300 ° C., a load of 5 g and a 2-cycle measurement were performed in a tension mode in a nitrogen atmosphere. The linear thermal expansion coefficient was an average linear thermal expansion coefficient at a temperature of 25 to 100 ° C. in the second cycle.

<(3) relative dielectric constant, (4) dielectric loss tangent>
The base material (PET film or copper foil) was removed from the resin sheet obtained above, and then a 50 um thick resin plate was obtained by heat curing at 200 ° C. for 1 hour with a drier in a nitrogen atmosphere. The obtained resin plate was cut into 20 mm × 50 mm, and 16 sheets were stacked to 1.6 mm thickness, and the relative dielectric constant and dielectric loss tangent value of 1 GHz were measured by the triplate line resonator method.

<(5) Water absorption rate>
The base material (PET film or copper foil) was removed from the resin sheet obtained above, and then a 50 um thick resin plate was obtained by heat curing at 200 ° C. for 1 hour with a drier in a nitrogen atmosphere. The obtained resin plate was cut into 50 mm × 50 mm and measured according to JIS6481.

<(6) Peel strength measurement>
In the process of manufacturing the printed wiring board manufactured as described above, the peel strength of a part of the outer layer copper foil of the printed wiring board was measured according to JIS 6481 before the solder resist was formed.

<(7) Peel strength measurement after PCT treatment>
In the process of manufacturing the printed wiring board produced above, a part of the printed wiring board is subjected to a pressure cooker (PCT) treatment (121 ° C., 100% RH, 2.1 atmm 50 hours treatment) before the solder resist is formed. The peel strength was measured according to JIS6481.

<(8) Thermal shock test>
The semiconductor device obtained above is put in Fluorinert. In Fluorinert, -55 ° C for 10 minutes, 125 ° C for 10 minutes, and -55 ° C for 10 minutes are treated for 1000 cycles, and no cracks are generated in the test piece. It was confirmed visually.
Each code is as follows.
○: No crack occurrence ×: Crack occurrence

As is apparent from the evaluation results of Examples 1 to 5 in Table 1, the resin composition had a high glass transition temperature of 190 ° C. or higher, and was excellent in low thermal expansion of 40 ppm or less as the linear thermal expansion coefficient of the resin composition. In particular, the water absorption was low. Further, the peel strength after the pressure cooker treatment was particularly excellent. Furthermore, since the thermal expansion was low and the glass transition temperature was high, the mounting reliability of the semiconductor device was also a result. On the other hand, the comparative example 1 brought a result with a high water absorption rate especially compared with the Example. In addition, the peel strength after the pressure cooker treatment also decreased.

  According to the present invention, since a highly reliable resin composition required as a resin layer can be obtained, it can be used as an insulating material such as a printed wiring board that requires fine processing for high density. In addition, printed circuit boards for electronic devices that require miniaturization of parts, high-speed signal transmission, and high reliability can be obtained, making semiconductor devices with high density, thinness, and excellent reliability. Applicable.

Claims (9)

    An insulating resin layer comprising a resin composition containing (A) a dicyclopentadiene-type cyanate resin, (B) an epoxy resin, and (C) an inorganic filler as essential components is formed on a substrate. Resin sheet.   The resin sheet according to claim 1, wherein the (A) dicyclopentadiene-type cyanate resin is 5 to 60% by weight based on the entire resin composition.   The resin sheet according to claim 1, wherein the (B) epoxy resin is an aryl alkylene type epoxy resin.   The resin sheet according to any one of claims 1 to 3, wherein the (C) inorganic filler is an inorganic filler having an average particle diameter of 0.01 to 5 µm.   The resin sheet according to any one of claims 1 to 4, wherein the (C) inorganic filler is at least one inorganic filler selected from the group consisting of spherical silica, calcined talc, and monohydrated alumina.   The resin sheet according to claim 1, wherein the (C) inorganic filler is 30 to 80 wt% of the entire resin composition.   A printed wiring board formed by heating and press-molding the resin sheet according to any one of claims 1 to 6 on one or both sides of an inner layer circuit board,   A circuit forming process including desmear, electroless plating, and electrolytic plating steps after the resin sheet according to any one of claims 1 to 7 is heated and pressed over one or both sides of an inner circuit board. A printed wiring board having a circuit formed by using a circuit; A semiconductor device in which a semiconductor element is mounted on the printed wiring board according to claim 7.