JP5696786B2 - Prepreg, laminated board, semiconductor package, and laminated board manufacturing method - Google Patents

Description

  The present invention relates to a prepreg, a laminate, a semiconductor package, and a method for manufacturing the laminate.

  Along with the recent demand for higher functionality and lighter and thinner electronic devices, miniaturization of semiconductor devices used in these electronic devices is progressing rapidly.

  On the other hand, in order to reduce the size of a semiconductor device, it is necessary to increase the density of a circuit board to be used. Therefore, the number of through holes that have been vacated for connection between circuits has increased compared to the conventional case, and the hole density has increased. It's getting higher. As the hole density increases, the distance between the walls of the through hole approaches, so that ion migration that causes the metal ions to migrate along the single fiber of the fiber base and short-circuit the circuit tends to occur. When this ion migration occurs, the insulation reliability of the circuit board decreases (for example, see Patent Documents 1 and 2).

In patent document 3 (Unexamined-Japanese-Patent No. 2004-149577), air permeability is set to 2-4 cm < ³ > / cm < ² > / sec by performing at least one process of a flattening process and a fiber opening process with respect to a glass cloth. There is described a prepreg in which a base material is impregnated with a thermosetting resin composition and the thermosetting resin composition is in a B-stage state.

Since the laminate using such a prepreg improves the impregnation property of the thermosetting resin composition into the fiber substrate, the strength of the laminate is made uniform. Therefore, the inner wall of the hole formed by the drilling process can be formed smoothly, and the occurrence of ion migration can be suppressed even when the hole density is increased and the distance between the walls of the through hole is reduced. It is described.
In addition, it is described that, by the fiber opening treatment, the glass fiber yarn spreads spatially, the impregnation into the glass fiber is improved, and voids are reduced, so that the occurrence of migration can be suppressed.

JP 2004-322364 A JP-A-6-316643 JP 2004-149577 A

  However, when the above flattening process or fiber opening process is performed on a fiber base material such as a glass cloth, the fiber base material may become fuzzy. When fluff is generated on the fiber base material, the strength of the fiber base material is reduced, or the resin puddle is generated at the protruding portion of the fluff, and the surface of the prepreg is roughened.

  Therefore, the technique of processing the fiber base material as described in Patent Document 3 to improve the insulation reliability of the laminated plate is effective in improving the insulation reliability, but is still improved in terms of yield. There was room for.

  In view of the above, an object of the present invention is to provide a prepreg having a good yield and a laminate having excellent insulation reliability.

  The present inventors diligently studied the mechanism of ion migration. As a result, it was found that when the nitrogen content in the prepreg is reduced to 0.10% by mass or less, the ion migration resistance is improved.

That is, according to the present invention,
A prepreg obtained by impregnating a fiber base material with a resin composition containing an epoxy resin and an epoxy resin curing agent,
The nitrogen content in the prepreg is 0.10% by mass or less,
A prepreg in which the air permeability of the fiber base material is 3.0 cm ³ / cm ² / sec or more and 30.0 cm ³ / cm ² / sec or less is provided.

  According to this invention, by using the prepreg having a nitrogen content of 0.10% by mass or less, the ion migration resistance of the laminate can be improved even when a fiber base material having the above air permeability is used. it can. In addition, the fiber base material having the above air permeability has suppressed the occurrence of fuzz and can improve the yield of the prepreg.

Furthermore, according to the present invention,
A laminate including the cured product of the prepreg is provided.

Furthermore, according to the present invention,
There is provided a semiconductor package in which a semiconductor element is mounted on a circuit board obtained by processing a circuit of the laminated plate.

Furthermore, according to the present invention,
A step of impregnating a fiber base material with a resin varnish containing an epoxy resin, an epoxy resin curing agent and a solvent to obtain a prepreg;
Heating the prepreg to obtain a cured product of the prepreg, and then
A method of manufacturing a laminated board that performs a step of forming a via with a laser,
The theoretical nitrogen content in the resin varnish is 0.50% by mass or less,
Provided is a method for producing a laminated board, wherein the fiber base has an air permeability of 3.0 cm ³ / cm ² / sec or more and 30.0 cm ³ / cm ² / sec or less.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated board excellent in insulation reliability can be obtained, and the prepreg with a favorable yield can be provided.

The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.
It is sectional drawing which shows an example of a structure of the prepreg in this embodiment. It is sectional drawing which shows an example of a structure of the semiconductor package in this embodiment. It is sectional drawing which shows an example of a structure of the semiconductor device in this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate. Moreover, the figure is a schematic diagram and does not necessarily match the actual dimensional ratio.

(Prepreg)
First, the configuration of the prepreg in the present embodiment will be described. FIG. 1 is a cross-sectional view showing an example of the configuration of a prepreg in the present embodiment. The prepreg 100 is obtained by impregnating the fiber substrate 101 with a resin composition P containing (A) an epoxy resin and (B) an epoxy resin curing agent.

The nitrogen content in the prepreg 100 is 0.10% by mass or less, preferably 0.08% by mass or less, and more preferably 0.05% by mass or less. When the nitrogen content in the prepreg 100 is not more than the above upper limit value, the ion migration resistance of the laminate can be improved. Therefore, special processing treatments such as flattening processing and fiber opening processing performed on the fiber base material in order to improve ion migration resistance can be suppressed. Therefore, the occurrence of fluffing of the fiber base material is suppressed, and the yield of the prepreg can be improved.
The reason why the ion migration resistance of the laminate is improved is not necessarily clear, but is presumed as follows. When the nitrogen content in the prepreg 100 is reduced, the moisture resistance of the prepreg 100 is improved. For this reason, moisture hardly adheres to the inside of the laminate obtained from the prepreg 100, in particular, the gap between the fiber base material and the resin, and metal ionization and metal ion migration hardly occur. As a result, it is assumed that the occurrence of ion migration is suppressed.

The nitrogen content in the prepreg 100 can be generally measured by a known method. For example, the prepreg is combusted and decomposed by using an organic element analyzer, the generated gas is converted to N ₂ , and heat conduction is performed. It can be measured by a degree detector.

Further, the air permeability of the fiber base material 101 in the prepreg 100 is 3.0 cm ³ / cm ² / sec or more, more preferably 3.5 cm ³ / cm ² / sec or more, and particularly preferably 4.0 cm. ³ / cm ² / sec or more. Since the prepreg 100 in this embodiment has excellent ion migration resistance, a fiber base material having an air permeability equal to or higher than the lower limit value can be used. In other words, it is possible to suppress special processing such as flattening or fiber opening performed on the fiber base material in order to improve the ion migration resistance. Therefore, since the occurrence of fluffing of the fiber base material 101 is suppressed, a resin pool that tends to occur at the protruding portion of the fluff hardly occurs. Therefore, the yield of prepreg can be improved.
The air permeability of the fiber base material 101 is 30.0 cm ³ / cm ² / sec or less, more preferably 20.0 cm ³ / cm ² / sec or less, and further preferably 15.0 cm ³ / cm ^2. / Sec or less, particularly preferably 12.0 cm ³ / cm ² / sec or less. When the air permeability of the fiber base material 101 is not more than the above upper limit value, the impregnation property of the resin composition into the fiber base material is improved, so that the strength of the laminate can be made uniform. Therefore, the inner wall of the hole formed by the drilling process can be formed smoothly, and the occurrence of ion migration can be suppressed even when the hole density is increased and the distance between the walls of the through hole is reduced. .
Here, the air permeability of the fiber base material 101 can be adjusted, for example, by processing such as flattening or fiber opening.
The air permeability can be measured according to JIS R3420 method (Fragile method).

Next, the material constituting the prepreg 100 will be described in detail.
The prepreg 100 in this embodiment is a fiber obtained by impregnating a fiber base material 101 with a resin composition P containing (A) an epoxy resin and (B) an epoxy resin curing agent, and then semi-curing the fiber. This is a sheet-like material including a base material 101 and resin layers 103 and 104. A sheet-like material having such a structure is preferable because it is excellent in various properties such as dielectric properties, mechanical and electrical connection reliability under high temperature and high humidity, and suitable for manufacturing a laminated board for a circuit board.

(Resin composition)
Hereinafter, the resin composition P impregnated into the fiber base material 101 is not particularly limited as long as it contains (A) an epoxy resin and (B) an epoxy resin curing agent, but it has a low linear expansion coefficient and a high elastic modulus. It is preferable that it has excellent thermal shock reliability.

(A) The epoxy resin is a compound having one or more glycidyl groups in the molecule, and is a compound that forms a three-dimensional network structure and cures when the glycidyl group reacts by heating. (A) The epoxy resin preferably contains two or more glycidyl groups in one molecule, but this does not show sufficient cured product properties even if the glycidyl group is reacted with only one compound. Because.
Specific examples of the (A) epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, and bisphenol Z. Bisphenol type epoxy resins such as epoxy resins or derivatives thereof, phenol novolac type epoxy resins, novolac type epoxy resins such as cresol novolac type epoxy resins, arylalkylene type epoxy resins such as biphenyl type epoxy resins and biphenyl aralkyl type epoxy resins, Naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, Adamantane type epoxy resins, such as epoxy resins and fluorene type epoxy resins. One of these can be used alone, or two or more can be used in combination.

  (A) Although content of an epoxy resin is not specifically limited, It is preferable that it is 15 to 80 mass% of the resin composition P whole. More preferably, it is 25 mass% or more and 60 mass% or less. In addition, it is preferable to use a liquid epoxy resin such as a liquid bisphenol A type epoxy resin or a bisphenol F type epoxy resin because the impregnation property to the fiber base material 101 can be improved. The content of the liquid epoxy resin is more preferably 3% by mass or more and 30% by mass or less of the entire resin composition P. Moreover, when solid bisphenol A type epoxy resin and bisphenol F type epoxy resin are used in combination, adhesion to the conductor can be improved.

  (B) Although it does not specifically limit as an epoxy resin hardening | curing agent, For example, a phenol type hardening | curing agent, an aliphatic amine, an aromatic amine, a dicyandiamide, a dihydrazide compound, an acid anhydride etc. are mentioned. Among these, organic compounds that do not contain a nitrogen atom in the chemical formula are particularly preferred, and phenolic curing agents and acid anhydrides that do not contain a nitrogen atom in the chemical formula are particularly preferred. When a phenolic curing agent or acid anhydride is used, a prepreg having a nitrogen content of 0.10% by mass or less can be obtained more efficiently.

(B) A phenolic curing agent as an epoxy resin curing agent is a compound having two or more phenolic hydroxyl groups in one molecule. In the case of a compound having one phenolic hydroxyl group in one molecule, since a crosslinked structure cannot be taken, the cured product characteristics deteriorate and cannot be used.
As the phenolic curing agent, for example, phenol novolak resin, alkylphenol novolak resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, zylock type phenol resin, terpene modified phenol resin, polyvinylphenols, etc. Two or more types can be used in combination.

    The blending amount of the phenol curing agent is preferably such that (A) the equivalent ratio to the epoxy resin (phenolic hydroxyl group equivalent / epoxy group equivalent) is from 0.1 to 1.0. As a result, there remains no unreacted phenol curing agent, and the moisture absorption heat resistance is improved. When the resin composition P uses an epoxy resin and a cyanate resin in combination, the range of 0.2 to 0.5 is particularly preferable. This is because the phenol resin not only acts as a curing agent but also promotes curing of the cyanate group and the epoxy group.

  (B) Examples of acid anhydrides as epoxy resin curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenyl succinic acid. An anhydride, maleic anhydride, etc. are mentioned.

  (B) Examples of the dihydrazide compound as the epoxy resin curing agent include carboxylic acid dihydrazides such as adipic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, and p-oxybenzoic acid dihydrazide.

Moreover, you may use together the following (C) curing catalyst for the resin composition P to such an extent that the nitrogen content in the obtained prepreg 100 does not exceed 0.10 mass%. The (C) curing catalyst is a catalyst that has a function of promoting the curing reaction between the (A) epoxy resin and the (B) epoxy resin curing agent, and is distinguished from the (B) epoxy resin curing agent. .
For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), trisacetylacetonate cobalt (III), triethylamine, tributylamine, diazabicyclo [2,2 , 2] tertiary amines such as octane, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methyl Imidazoles, 2-phenyl-4-methyl-5-hydroxyimidazole, imidazoles such as 2-phenyl-4,5-dihydroxyimidazole, phenolic compounds such as phenol, bisphenol A, nonylphenol, acetic acid, benzoic acid, salicylic acid And organic acids such as p-toluenesulfonic acid, etc. onium salt compound, or a mixture thereof. (C) As a curing catalyst, one kind including these derivatives can be used alone, or two or more kinds including these derivatives can be used in combination.

  (C) Content of a curing catalyst will not be specifically limited if the nitrogen content in the obtained prepreg 100 does not exceed 0.10 mass%. For example, 0.010 mass% or more of the whole resin composition P is preferable, and 0.10 mass% or more is particularly preferable. (C) The effect which accelerates | stimulates hardening can fully be acquired as content of a curing catalyst is more than the said lower limit. Further, the content of the (C) curing catalyst is preferably 5.0% by mass or less, and particularly preferably 2.0% by mass or less, based on the entire resin composition P. (C) The fall of the preservability of the prepreg 100 can be suppressed as content of a curing catalyst is below the said upper limit.

  The resin composition P preferably further contains (D) an inorganic filler. (D) Examples of inorganic fillers include silicates such as talc, calcined clay, unfired clay, mica and glass, oxides such as titanium oxide, alumina, silica and fused silica, calcium carbonate, magnesium carbonate and hydrotalc. Carbonate such as site, hydroxide such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, sulfate or sulfite such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate And borate salts such as calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride, titanates such as strontium titanate and barium titanate. One of these can be used alone, or two or more can be used in combination.

  Among these, silica is particularly preferable, and fused silica (especially spherical fused silica) is preferable in terms of excellent low thermal expansion. The shape is crushed and spherical, but in order to reduce the melt viscosity of the resin composition P in order to ensure the impregnation of the fiber base material 101, a method of use that suits the purpose, such as using spherical silica, is adopted. Is done.

  (D) The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.01 μm or more and 3 μm or less, and particularly preferably 0.02 μm or more and 1 μm or less. (D) By making the particle size of an inorganic filler 0.01 micrometer or more, a varnish can be made low viscosity and the fiber base material 101 can be made to impregnate the resin composition P favorably. Moreover, by setting it as 3 micrometers or less, sedimentation etc. of (D) inorganic filler can be suppressed in a varnish. This average particle diameter can be measured by, for example, a particle size distribution meter (manufactured by Shimadzu Corporation, product name: laser diffraction particle size distribution measuring device SALD series).

  Further, (D) the inorganic filler is not particularly limited, but an inorganic filler having a monodispersed average particle diameter can be used, and an inorganic filler having a polydispersed average particle diameter can be used. Furthermore, one type or two or more types of inorganic fillers having an average particle size of monodisperse and / or polydisperse can be used in combination.

  Furthermore, spherical silica (especially spherical fused silica) having an average particle size of 3 μm or less is preferable, and spherical fused silica having an average particle size of 0.02 μm or more and 1 μm or less is particularly preferable. Thereby, the filling property of (D) inorganic filler can be improved.

  (D) Although content of an inorganic filler is not specifically limited, 2 mass% or more and 70 mass% or less of the whole resin composition P are preferable, and 5 mass% or more and 60 mass% or less are especially preferable. When the content is within the above range, particularly low thermal expansion and low water absorption can be achieved.

  Moreover, it is although it does not specifically limit in the resin composition P, It is preferable to further contain (E) coupling agent. (E) Coupling agent improves (A) epoxy resin and (D) inorganic filling with respect to fiber base material by improving the wettability of the interface of (A) epoxy resin and (D) inorganic filler. The material can be fixed uniformly, and the heat resistance, particularly the solder heat resistance after moisture absorption can be improved.

  (E) Any commonly used coupling agent can be used. Specifically, epoxy silane coupling agents, cationic silane coupling agents, aminosilane coupling agents, titanate coupling agents, and silicone oil types. It is preferable to use one or more coupling agents selected from coupling agents. Thereby, (D) wettability with the interface of an inorganic filler can be made high, and thereby heat resistance can be improved more.

  (E) The addition amount of the coupling agent depends on the specific surface area of the (D) inorganic filler and is not particularly limited. However, (D) 0.05% by mass to 5% by mass with respect to 100 parts by mass of the inorganic filler. The following is preferable, and 0.1 mass% or more and 3 mass% or less are especially preferable. By setting the content to 0.05% by mass or more, (D) the inorganic filler can be sufficiently covered, and the heat resistance can be improved. By setting the content to 5% by mass or less, the reaction proceeds satisfactorily and a decrease in bending strength or the like can be prevented.

The resin composition P may contain a thermosetting resin other than an epoxy resin such as a melamine resin, a urea resin, or a cyanate resin, and it is particularly preferable to use a cyanate resin in combination.
Although it does not specifically limit as a kind of cyanate resin, For example, bisphenol-type cyanate resin, such as a novolak-type cyanate resin, a bisphenol A-type cyanate resin, a bisphenol E-type cyanate resin, a tetramethylbisphenol F-type cyanate resin, etc. can be mentioned. Among these, phenol novolac type cyanate resin is preferable from the viewpoint of low thermal expansion. Furthermore, other cyanate resins may be used alone or in combination of two or more, and are not particularly limited. The cyanate resin is preferably 8% by mass or more and 20% by mass or less of the entire resin composition P.

  The resin composition P includes a phenoxy resin, a polyimide resin, a polyamideimide resin, a polyamide resin, a polyphenylene oxide resin, a polyethersulfone resin, a polyester resin, a polyethylene resin, a polystyrene resin, and other thermoplastic resins, styrene-butadiene copolymer Polystyrene, thermoplastic elastomers such as styrene-isoprene copolymers, thermoplastic elastomers such as polyolefin thermoplastic elastomers, polyamide elastomers, polyester elastomers, polybutadiene, epoxy-modified polybutadiene, acrylic-modified polybutadiene, methacryl-modified polybutadiene, etc. These diene elastomers may be used in combination. Among these, heat-resistant polymer resins such as phenoxy resin, polyimide resin, polyamideimide resin, polyamide resin, polyphenylene oxide resin, and polyethersulfone resin are preferable. Thereby, the thickness uniformity of the prepreg 100 is excellent, and as a wiring board, the heat resistance and the insulating property of the fine wiring are excellent. In addition, the resin composition P may contain additives other than the above components such as pigments, dyes, antifoaming agents, leveling agents, ultraviolet absorbers, foaming agents, antioxidants, flame retardants, and ion scavengers as necessary Things may be added.

  The fiber base material 101 impregnated with the resin composition P is not particularly limited, but glass fiber base materials such as glass cloth, glass woven fabric and glass nonwoven fabric, carbon fiber base materials such as carbon cloth and carbon fiber woven fabric, rock wool, etc. Man-made mineral base materials, polyamide resin fibers, aromatic polyamide resin fibers, polyamide resin fibers such as wholly aromatic polyamide resin fibers, polyester resins such as polyester resin fibers, aromatic polyester resin fibers, wholly aromatic polyester resin fibers Synthetic fiber substrate composed of woven or non-woven fabric mainly composed of fiber, polyimide resin fiber, fluororesin fiber, etc., kraft paper, cotton linter paper, mixed paper of linter and kraft pulp, etc. Examples thereof include organic fiber base materials such as materials. Among these, a glass fiber base material is preferable. Thereby, a prepreg having low water absorption, high strength, and low thermal expansion can be obtained.

  Examples of the glass constituting the glass fiber substrate include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and H glass. Among these, E glass or T glass is preferable. Thereby, the high elasticity of a prepreg can be achieved and the thermal expansion coefficient of a prepreg can be reduced.

The fiber base material used in the present embodiment, it is preferable that the basis weight (weight of the fiber base material per 1 m ²⁾ is of 145 g / ^{m 2} or more 300 g / ^{m 2} or less, more preferably 160 g / ^{m 2} It is 230 g / m ² or more, more preferably 190 g / m ² or more and 205 g / m ² or less.

  When the basis weight is not more than the above upper limit value, the impregnation property of the resin composition in the fiber base material is improved, and a decrease in strand voids and insulation reliability can be suppressed. In addition, formation of a through hole with a laser such as carbon dioxide, UV, or excimer may be facilitated. Moreover, the intensity | strength of a glass cloth or a prepreg improves that basic weight is more than the said lower limit. As a result, handling may be improved, prepregs may be easily manufactured, and the effect of reducing substrate warpage may be improved.

  Although the thickness of a fiber base material is not specifically limited, It is preferable that they are 50 micrometers or more and 300 micrometers or less, More preferably, they are 80 micrometers or more and 250 micrometers or less, More preferably, they are 100 micrometers or more and 200 micrometers or less. By using the fiber base material having such a thickness, the handling property at the time of manufacturing the prepreg is further improved, and the warp reduction effect is particularly remarkable.

  When the thickness of the fiber base material is not more than the above upper limit, the impregnation property of the resin composition in the fiber base material can be improved, and the decrease in strand voids and insulation reliability can be suppressed. In addition, formation of a through hole with a laser such as carbon dioxide, UV, or excimer may be facilitated. Moreover, the intensity | strength of a glass cloth or a prepreg improves that basic weight is more than the said lower limit. As a result, handling may be improved, prepregs may be easily manufactured, and the effect of reducing substrate warpage may be improved.

  Further, the number of fiber base materials used is not limited to one, and a plurality of thin fiber base materials can be used in a stacked manner. In addition, when using a plurality of fiber base materials in piles, the total thickness only needs to satisfy the above range.

It continues and demonstrates the manufacturing method of the prepreg 100 in detail.
The prepreg 100 in the present embodiment is obtained by impregnating a fiber base material 101 with a resin composition P containing (A) an epoxy resin and (B) an epoxy resin curing agent, and then semi-curing it.

  The method of impregnating the fiber base material 101 with the resin composition P is, for example, a method of preparing a resin varnish V using the resin composition P, immersing the fiber base material 101 in the resin varnish V, and a resin varnish V using various coaters. The method of apply | coating, the method of spraying the resin varnish V by spray, the method of laminating the resin layer with a support base material on a fiber base material, etc. are mentioned. Among these, the method of immersing the fiber substrate 101 in the resin varnish V and the method of laminating the resin layer with a supporting substrate on the fiber substrate are preferable. The method of immersing the fiber base material 101 in the resin varnish V can improve the impregnation property of the resin composition P with respect to the fiber base material 101. In addition, when the fiber base material 101 is immersed in the resin varnish V, a normal impregnation coating equipment can be used.

  In particular, when the thickness of the fiber substrate 101 is 0.1 mm or less, a method of laminating a resin layer with a supporting substrate on the fiber substrate is preferable. Thereby, the impregnation amount of the resin composition P with respect to the fiber base material 101 can be adjusted freely, and the moldability of a prepreg can further be improved. In addition, when laminating a film-like resin layer, it is more preferable to use a vacuum laminating apparatus or the like.

The solvent used in the resin varnish V desirably has good solubility in the resin component in the resin composition P, but a poor solvent may be used within a range that does not adversely affect the resin varnish V. Solvents exhibiting good solubility include, for example, alcohols such as methanol and ethanol, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellosolve type And carbitol series.
Among these, an organic compound that does not contain a nitrogen atom in the chemical formula is particularly preferable as a solvent, and alcohols, methyl ethyl ketone, and toluene are particularly preferable. When an organic compound not containing a nitrogen atom in the chemical formula is used, a prepreg having a nitrogen content of 0.10% by mass or less can be obtained more efficiently.

  The solid content of the resin varnish V is not particularly limited, but the solid content of the resin composition P is preferably 20% by mass to 90% by mass, and particularly preferably 50% by mass to 80% by mass. Thereby, the impregnation property to the fiber base material 101 of the resin varnish V can further be improved. Although the predetermined temperature which makes the fiber base material 101 impregnate the resin composition P is not specifically limited, For example, the prepreg 100 can be obtained by drying at 90 degreeC or more and 220 degrees C or less. The thickness of the prepreg 100 is preferably 20 μm or more and 100 μm or less.

Further, the theoretical nitrogen content in the resin varnish V is 0.50% by mass or less, preferably 0.20% by mass or less, and more preferably 0.10% by mass or less. When the theoretical nitrogen content in the resin varnish V is not more than the above upper limit, a prepreg having a nitrogen content of 0.10% by mass or less can be obtained more efficiently.
The theoretical nitrogen content in the resin varnish V is a value calculated on the assumption that the nitrogen contained in the resin varnish V is derived only from a component containing a nitrogen atom in the chemical formula. Specifically, the nitrogen content contained in each component is calculated from the molecular weight and the number of nitrogen atoms, the total weight is divided by the weight of the entire resin varnish, and the obtained value is expressed in%.

  In the prepreg 100, the thickness of the resin layer 103 and the resin layer 104 may be substantially the same or different with the fiber base 101 as the center, with the fiber base 101 as the center. In other words, in the prepreg 100, the center in the thickness direction of the fiber base material may be shifted from the center in the thickness direction of the prepreg.

(Laminated board)
Below, the structure of the laminated board in this embodiment is demonstrated. The laminate in the present embodiment includes a cured body of prepreg obtained by curing the prepreg 100 described above.

(Laminate production method)
Then, the manufacturing method of the laminated board using the prepreg 100 obtained above is demonstrated. Although the manufacturing method of the laminated board using a prepreg is not specifically limited, For example, it is as follows.
Laminate one or more prepregs, overlap metal foils on both the top and bottom sides or one side of the outside, and join them under high vacuum conditions using a laminator or becquerel unit, or directly on top and bottom or both sides on the outside of the prepreg Stack metal foil.
Next, a laminated plate can be obtained by heating and pressurizing a prepreg with a metal foil on a vacuum press or heating with a dryer.
The thickness of the metal foil is, for example, 1 μm or more and 35 μm or less. More preferably, they are 2 micrometers or more and 25 micrometers or less. When the thickness of the metal foil is equal to or more than the lower limit, it is possible to sufficiently ensure the mechanical strength when manufacturing the laminated plate. Further, when the thickness is not more than the above upper limit value, it is possible to easily process and form a fine circuit.

  Examples of the metal constituting the metal foil include copper and copper alloys, aluminum and aluminum alloys, silver and silver alloys, gold and gold alloys, zinc and zinc alloys, nickel and nickel alloys, tin and tin alloys. Alloys, iron and iron-based alloys, Kovar (trade name), 42 alloys, Fe-Ni alloys such as Invar or Super Invar, W or Mo, and the like can be given. Also, an electrolytic copper foil with a carrier can be used.

  Although it does not specifically limit as said heat-processing method, For example, it can implement using a hot-air drying apparatus, an infrared heating apparatus, a heating roll apparatus, a flat platen hot-plate press apparatus, etc. When a hot-air drying device or an infrared heating device is used, the bonding can be carried out without substantially applying pressure to the joined ones. Moreover, when using a heating roll apparatus or a flat hot platen press apparatus, it can implement by making predetermined | prescribed pressure act on the said joined thing.

  The temperature during the heat treatment is not particularly limited, but it is preferably a temperature range in which the resin used melts and the resin curing reaction does not proceed rapidly. The temperature at which the resin melts is preferably 120 ° C. or higher, more preferably 150 ° C. or higher. The temperature at which the resin curing reaction does not proceed rapidly is preferably 250 ° C. or lower, more preferably 230 ° C. or lower.

In addition, since the time for the heat treatment varies depending on the type of resin used and the like, it is not particularly limited. For example, the heat treatment can be performed by treating for 30 minutes to 300 minutes.
Moreover, the pressure to pressurize is not particularly limited, but is preferably 0.2 MPa or more and 6 MPa or less, and more preferably 2 MPa or more and 5 MPa or less.

  Moreover, you may laminate | stack a film on the at least one surface of the laminated board in this embodiment instead of metal foil. Examples of the film include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyimide, and fluorine resin.

(Semiconductor package)
Next, the semiconductor package 200 in the present embodiment will be described.
The obtained laminated plate can be used for a semiconductor package 200 as shown in FIG. As a manufacturing method of the semiconductor package 200, for example, there are the following methods.
A through hole 215 for interlayer connection is formed in the laminate 213, and a wiring layer is manufactured by a subtractive method, a semi-additive method, or the like. Thereafter, build-up layers (not shown in FIG. 2) are stacked as necessary, and the steps of interlayer connection and circuit formation by the additive method are repeated. And if necessary, the solder resist layer 201 is laminated | stacked, and a circuit is formed by the method according to the above, and a circuit board is obtained. Here, some or all of the buildup layers and the solder resist layer 201 may or may not include a fiber base material.

  Next, after a photoresist is applied to the entire surface of the solder resist layer 201, a part of the photoresist is removed to expose a part of the solder resist layer 201. Note that a resist having a photoresist function may be used for the solder resist layer 201. In this case, the step of applying a photoresist can be omitted. Next, the exposed solder resist layer is removed to form the opening 209.

  Subsequently, by performing a reflow process, the semiconductor element 203 is fixed to the connection terminal 205 which is a part of the wiring pattern via the solder bump 207. Then, the semiconductor package 203 as shown in FIG. 2 is obtained by sealing the semiconductor element 203, the solder bump 207, etc. with the sealing material 211. Then, as shown in FIG.

(Semiconductor device)
Next, the semiconductor device 300 in this embodiment will be described.
The semiconductor package 200 can be used in a semiconductor device 300 as shown in FIG. A method for manufacturing the semiconductor device 300 is not particularly limited, and examples thereof include the following methods.

  First, the solder bump 301 is formed by supplying a solder paste to the opening 209 of the solder resist layer 201 of the obtained semiconductor package 200 and performing a reflow process. The solder bump 301 can also be formed by attaching a solder ball prepared in advance to the opening 209.

  Next, the semiconductor package 200 is mounted on the mounting substrate 303 by bonding the connection terminals 305 and the solder bumps 301 of the mounting substrate 303, and the semiconductor device 300 shown in FIG. 3 is obtained.

  As described above, according to the present embodiment, the prepreg 100 for the laminated plate 213 having excellent insulation reliability can be provided. And the circuit board using the laminated board 213 is excellent in insulation reliability. Therefore, the laminated board 213 in the present embodiment can be suitably used for applications that require further insulation reliability, such as printed wiring boards that require higher density and higher multilayer.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable. For example, in this embodiment, although the case where the prepreg was one layer was shown, you may produce a laminated board using what laminated | stacked the prepreg 100 one or more layers.
Moreover, the structure which laminated | stacked the buildup layer further on the laminated board in this embodiment can also be taken. Moreover, you may use the prepreg 100 in this embodiment also for the prepreg used for a buildup layer or a soldering resist layer. In this case, it is possible to obtain the semiconductor package 200 and the semiconductor device 300 that are further excellent in insulation reliability.

Hereinafter, although an example , a reference example, and a comparative example explain the present invention, the present invention is not limited to these. In addition, in an Example, unless otherwise specified, a part represents a mass part. Moreover, each thickness is represented by the average film thickness.

In the examples , reference examples, and comparative examples, the following raw materials were used.
(1) Brominated bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, 5047, epoxy equivalent 560)
(2) Bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, 828, epoxy equivalent 190)
(3) Bisphenol F type epoxy resin (DIC, 830S, epoxy equivalent 170)
(4) 1,1,2,2-tetrakis (glycidylphenyl) ethane type epoxy resin (manufactured by Mitsubishi Chemical Corporation, 1031, epoxy equivalent 220)
(5) Phenol novolac resin (DIC Corporation, TD-2090, hydroxyl group equivalent 105)
(6) Phenol aralkyl resin (Mitsui Chemicals, XLC-LL, hydroxyl group equivalent 175)
(7) Bisphenol A novolak resin (DIC, VH-4170, hydroxyl group equivalent 115)
(8) 2-Phenylimidazole (manufactured by Shikoku Chemicals)
(9) Epoxysilane (Shin-Etsu Silicone, KBM-403)
(10) Fused silica (manufactured by Admatechs, SO-E2, average particle size 0.5 μm)
(11) Aluminum hydroxide (Nippon Light Metal Co., Ltd., BE-033, average particle size 3.0 μm)
(12) Dicyandiamide (Degussa)
(13) 4,4′-diaminodiphenylmethane (manufactured by Tokyo Chemical Industry Co., Ltd.)

Example 1
The laminated board in this invention was produced using the following procedures.

1. Preparation of varnish of resin composition 28.1 parts by mass of brominated bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, 5047, epoxy equivalent 560), bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, 828, epoxy equivalent 190) 20.0 parts by mass, phenol novolac resin (manufactured by DIC, TD-2090, hydroxyl equivalent 105) 16.3 parts by mass, 2-phenylimidazole (manufactured by Shikoku Chemicals) 0.03 parts by mass, epoxy silane ( 0.8 parts by mass of Shin-Etsu Silicone, KBM-403), 1.5 parts by mass of fused silica (manufactured by Admatechs, SO-E2, average particle size 0.5 μm), aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd.) , BE-033, average particle size 3.0 μm) is added to 33.3 parts by mass, 28.0 parts by mass of methyl ethyl ketone is added, and the mixture is stirred using a high-speed agitator. A resin varnish having a resin composition based on solid content of 78% by mass was obtained. Moreover, the theoretical nitrogen content mentioned above was computed. In Example 1, the component containing a nitrogen atom in the chemical formula is 2-phenylimidazole.

2. Production of prepreg Glass woven fabric (thickness 0.16 mm, basis weight 208.0 g / m ² , air permeability 5.1 cm ³ / cm ² / sec, manufactured by Nittobo Macao Co., Ltd.) 208.0 using the varnish described above. A prepreg having a resin composition content of 48.0% by mass was obtained by impregnating 192.0 parts by mass of the varnish with a solid content of the resin composition with respect to parts by mass and drying it in a drying furnace at 180 ° C. for 5 minutes. .
The air permeability of the glass woven fabric is as follows: a sample is cut into 200 mm × 500 mm, and a fragile measuring instrument (AP-360S manufactured by Daiei Scientific Co., Ltd.) is used. The amount of air passing through the cloth per second was obtained.

3. Manufacture of laminates 4 prepregs are stacked, 18 μm thick electrolytic copper foil (FTS made by Furukawa Circuit Foil Co., Ltd., GTSMP) is stacked on top and bottom, and heat press molding is performed at a pressure of 4 MPa and a temperature of 200 ° C. for 180 minutes. A double-sided copper clad laminate having a thickness of 0.8 mm was obtained.

4). Manufacture of printed wiring board After performing through-hole processing on the double-sided copper-clad laminate obtained above using a 65 μm drill bit, a swelling solution at 70 ° C. (Swelling Dip Securigant P, manufactured by Atotech Japan) For 5 minutes, and further immersed in an aqueous solution of potassium permanganate at 80 ° C. (Atotech Japan Co., Ltd., Concentrate Compact CP) for 15 minutes, followed by neutralization and desmear treatment in the through hole. Next, after the surface of the electrolytic copper foil layer is etched by about 1 μm by flash etching, an electroless copper plating is formed to a thickness of 0.5 μm, a resist layer for electrolytic copper plating is formed to a thickness of 18 μm, and pattern copper plating is performed. The film was post-cured by heating at 200 ° C. for 60 minutes. Next, the plating resist was removed and the entire surface was flash etched to form a pattern of L / S = 75/75 μm. Finally, a solder resist (PSR4000 / AUS308 manufactured by Taiyo Ink Co., Ltd.) having a thickness of 20 μm was formed on the circuit surface to obtain a double-sided printed wiring board.

(Examples 2 to 4, Examples 6 to 9 , Reference Examples and Comparative Examples 1 to 8)
A resin varnish was prepared in the same manner as in Example 1 except that a resin varnish was prepared according to the recipe shown in Table 1 and Table 2, and a prepreg, a laminate, and a printed wiring board were produced.
In addition, the following evaluations were performed on the prepregs and printed wiring boards obtained in the examples , reference examples, and comparative examples. The evaluation results are shown in Table 1.

1. Evaluation of prepreg (1) Occurrence of resin pools The occurrence of resin pools on the prepreg surface obtained in each of the Examples , Reference Examples, and Comparative Examples was visually evaluated. A resin puddle was confirmed as “no abnormality”, and a glass pavement fluff confirmed as having a resin puddle on the prepreg surface was “present”.
(2) Measurement of nitrogen content in prepreg The nitrogen content in the prepreg was measured by the following method.
The nitrogen content was measured as follows using an organic element analyzer (Perkin Elmer 2400IICHNS). 20 mg of the prepreg was taken and wrapped in a tin board, which was set in an apparatus, dropped into a combustion tube, burned in oxygen at 1000 ° C., and the generated nitrogen gas was detected with a thermal conductivity detector.

2. Evaluation of Printed Wiring Board (1) Solder heat resistance After the printed wiring boards obtained in the above Examples , Reference Examples and Comparative Examples were cut into 50 mm × 50 mm with a grinder saw and treated at 85 ° C. and 85% for 96 hours. After the sample was immersed in a solder bath at 260 ° C. for 30 seconds, the presence or absence of abnormal appearance was examined.
Evaluation criteria: No abnormality
: Swelled (there is a swelled area as a whole)

(2) Migration resistance 50V was applied to the through-hole part of the printed wiring board obtained by the said Example , reference example, and the comparative example on 85 degreeC85% conditions, and the insulation resistance after 300-hour processing was measured. The distance between the through hole and the wall of the through hole is 0.35 μm. Here, the insulation lowered to 10 ⁻⁸ Ω or less was ^defined as “insulation lowered”.

3. Evaluation Results As is clear from Table 1, Examples 1-4, Examples 6-9 , and Reference Example were free from resin and had excellent printed circuit board solder heat resistance and migration resistance.

Since Comparative Example 1 used a glass woven fabric having a low air permeability, a resin pool was generated.
Since Comparative Examples 2 and 3 used nitrogen as a solvent, solder heat resistance and migration resistance deteriorated.
Since Comparative Examples 4, 6, and 7 used nitrogen containing curing agents, the migration resistance deteriorated.
In Comparative Example 5, since a glass woven fabric having a low air permeability was used, a hardener containing nitrogen was used, but no migration occurred. However, since a glass woven fabric having a low air permeability was used, resin accumulation occurred.
Since Comparative Example 8 used a glass woven fabric having an air permeability exceeding 30 cm ³ / cm ² / sec, the migration resistance deteriorated.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2011-142630 for which it applied on June 28, 2011, and takes in those the indications of all here.

Claims (11)

A prepreg obtained by impregnating a fiber base material with a resin composition containing an epoxy resin and an epoxy resin curing agent,
The nitrogen content in the prepreg is 0.0024 % by mass or less,
The air permeability of the fibrous base material is not more than 3.0cm ³ / ^cm 2 / sec or more 30.0cm ³ / ^cm 2 / sec, the prepreg.   The prepreg according to claim 1, wherein the resin composition further contains a curing catalyst.   The prepreg according to claim 2, wherein the curing catalyst contains an imidazole compound. The basis weight of the fiber substrate, is 145 g / ^{m 2} or more 300 g / ^{m 2} or less, prepreg according to any one of claims 1 to 3.   The prepreg as described in any one of Claims 1 thru | or 4 whose thickness of the said fiber base material is 50 micrometers or more and 300 micrometers or less.   The prepreg according to any one of claims 1 to 5, wherein the fiber base material is a glass fiber base material.   A laminated board comprising the cured body of the prepreg according to any one of claims 1 to 6.   A semiconductor package comprising a semiconductor element mounted on a circuit board obtained by processing a circuit board of the laminated board according to claim 7. A step of impregnating a fiber base material with a resin varnish containing an epoxy resin, an epoxy resin curing agent and a solvent to obtain a prepreg;
Heating the prepreg to obtain a cured product of the prepreg, and then
A method of manufacturing a laminated board that performs a step of forming a via with a laser,
The theoretical nitrogen content in the resin varnish is 0.005 % by mass or less,
The air permeability of the fibrous base material is not more than 3.0cm ³ / ^cm 2 / sec or more 30.0cm ³ / ^cm 2 / sec, the production method of the laminated board. It is a manufacturing method of the laminated board of Claim 9, Comprising:
The said epoxy resin hardening | curing agent is a manufacturing method of a laminated board which is an organic compound which does not contain a nitrogen atom in chemical formula. It is a manufacturing method of the laminated board of Claim 9 or 10,
The said solvent is a manufacturing method of a laminated board which is an organic compound which does not contain a nitrogen atom in chemical formula.

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