JP4970326B2 - Resin composition and semiconductor sealing material using the same - Google Patents

Description

  The present invention relates to a resin composition excellent in solder crack resistance, adhesion, moisture resistance stability, and continuous moldability to various members such as a lead frame, and is particularly capable of injection molding suitable for a semiconductor sealing material. The present invention relates to a resin composition.

An epoxy resin composition is mainly used as a semiconductor sealing resin composition (hereinafter referred to as a resin composition) for transistors, capacitors, diodes, ICs, LSIs, etc. Among them, a polymer is used as a release agent component. Fatty acids, polymer fatty acid esters, and other polymer fatty acid compounds are employed from the viewpoints of moldability, reliability, mass productivity, and the like.
However, in recent market trends of downsizing, weight reduction, and price reduction of electronic devices, resin compositions are required to reduce molding time and yield in order to improve productivity.
In order to shorten the molding time, generally a measure of improving curability is taken, but as a result, the speed of thickening increases, the fluidity decreases, and the wettability between the frame and the sealing resin increases. As a result, the adhesion decreases, and as a result, solder crack resistance and moisture resistance reliability decrease.
Therefore, as a countermeasure against this, a method of increasing the fluidity due to the lubricant effect by increasing the amount of the release agent added has been adopted, but in this case, the adhesion inside the semiconductor device decreases as the fluidity improves. Interfacial peeling occurs and solder crack resistance and moisture resistance reliability are lowered, that is, sufficient performance cannot be achieved only by improving the curability and increasing the amount of release agent added.
In addition, long-chain fatty acid waxes such as stearic acid and montanic acid, metal salt waxes of long-chain fatty acids such as zinc stearate, magnesium stearate, and calcium stearate, carnauba wax and esterified products of montanic acid are used as release agents. A conventional ester wax not containing an amine, a bisamide wax represented by montanic acid bisamide, etc., or an oxidized polyolefin wax (Patent Document 1, Patent Document 2), or a urethane modification of an oxidized polyolefin wax Although it is known to use a thing (patent document 3) etc., compatibility with an epoxy resin composition is not necessarily enough, and expression of the said various performance was not enough.
Japanese Patent Laid-Open No. 2003-213080 JP 2005-225965 A JP 2003-268204 A

  Various improvements in improving fluidity, filling, continuous moldability, mold releasability, solder crack resistance, adhesion, and moisture resistance to various components such as lead frames and chips. As a result of investigations, the present inventors have found that the above characteristics are greatly improved by using an acid graft-modified modified polyolefin wax as a release agent component, and thus completed the present invention.

That is, the present invention relates to the following resin composition.
[1] A resin composition comprising a thermosetting resin (A), an inorganic filler (B), and a release agent (C), wherein the release agent (C) is a modified polyolefin wax that has been acid-grafted. The resin composition characterized by the above-mentioned.
[2] The resin composition according to [1], wherein the acid value of the modified polyolefin wax is 1 to 100 KOHmg / g.
[3] The resin composition according to [1], wherein the modified polyolefin wax is obtained by acid graft modification of a polyolefin wax produced with a metallocene catalyst.
[4] The resin according to [1], containing 0.03 to 1.00 parts by weight of a release agent (C) with respect to a total of 100 weights of the thermosetting resin (A) and the inorganic filler (B). Composition.
[5] A semiconductor sealing material comprising the resin composition according to any one of [1] to [4].

  By using the resin composition of the present invention, it is possible to obtain a semiconductor sealing material having continuous moldability, solder crack resistance to various members such as a lead frame, adhesion and moisture resistance stability.

   The present invention is described in detail below.

<Thermosetting resin (A)> The thermosetting resin (A) used for this invention consists of a main ingredient (a-1), a hardening | curing agent (a-2), and a hardening accelerator (a-3).
Main agent (a-1)
Examples of the main agent (a-1) include an epoxy resin, a phenol resin, a diallyl phthalate resin, a urea resin, and a polyester resin. The present invention is not particularly limited to these, but an epoxy resin and a phenol resin are preferably used. .
These resins may be used alone or in combination.
The epoxy resin used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, cresol novolak type epoxy resin, halogen An epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, etc. can be mentioned.
Among them, for the sealing of electronic components, from the viewpoint of heat resistance and moisture resistance, epoxy resins having an epoxy equivalent of 300 or less such as cresol novolac type and biphenyl type are preferably used, and two or more types of epoxy resins are used in combination. You can also.
Curing agent (a-2)
As a hardening | curing agent (a-2), if it carries out a hardening reaction with the said main ingredient (a-1), it can use without a restriction | limiting especially, A phenol resin, a melamine resin, an acrylic resin, an isocyanate resin etc. can be used. In particular, a phenol resin is preferable.
Examples of the phenol resin include a phenol novolac resin, a cresol novolac resin, an aralkyl phenol resin, and a terpene phenol resin.
The compounding quantity of a hardening | curing agent can be used as needed, and is 0-60 normally with respect to 100 weight part of main agents (a-1), Preferably it is 20-60 weight part, More preferably, it is 40-55 weight part. Yes, when expressed in terms of chemical equivalent ratio, the chemical equivalent ratio of the curing agent to the epoxy resin is in the range of 0.5 to 1.5, particularly 0.7 to 1.3 from the viewpoint of moisture resistance and mechanical properties. Is preferred.
Curing accelerator (a-3)
As a hardening accelerator (a-3) used by this invention, what is necessary is just to accelerate | stimulate the hardening reaction of an epoxy group and a phenolic hydroxyl group, and what is generally used for the sealing material is used widely. Can do.
For example, tributylamine, diazabicycloalkenes such as 1,8-diazabicyclo (5,4,0) undecene-7 and derivatives thereof, amine compounds such as benzyldimethylamine, tetraphenylphosphonium / tetranaphthoic acid borate, triphenyl Examples include organic phosphorus compounds such as phosphine, imidazole compounds such as 2-methylimidazole, and the like, but are not limited thereto.
These curing accelerators may be used alone or in combination of two or more.
The compounding quantity of a hardening accelerator can be used as needed, and is 0-20 normally with respect to a total of 100 weight part of a main ingredient (a-1) and a hardening | curing agent (a-2), Preferably it is 0.1. -10 parts by weight, more preferably 0.3-5 parts by weight.

<Inorganic filler (B)>
Examples of the inorganic filler (B) used in the present invention include talc, ferrite, graphite, silicon nitride, mica, calcium carbonate, clay, alumina, alumina silica, crushed silica, spherical silica, zeolite, zinc oxide, carbon, Examples include aluminum hydroxide, asbestos fibers, glass fibers, carbonate fibers, glass beads, shirasu balloons, silica balloons and the like in powder form, fiber form, and balloon form. In the present invention, the average particle diameter is preferably 5 to 50 μm, Examples thereof include silica powder having a maximum particle size of 50 to 200 μm, silicon nitride powder, zeolite powder and the like.
In the present invention, silica powder is particularly preferably used, and spherical fused silica is generally used for a compound with a large filling amount.
These inorganic fillers may be used alone or in combination.
In the present invention, the blending ratio of the thermosetting resin (A) to the inorganic filler (B) is usually (A) / (B) = 50/50 to 3/97, preferably 45/55 to 4/96, Preferably it is 40 / 60-5 / 95. It is preferable that the ratio of (A) to (B) is in the above range because the moldability and adhesion are excellent and the linear expansion coefficient is small.

<Release agent (C)>
The release agent used in the release agent (C) of the present invention is a modified polyolefin wax that has been acid-grafted. Hereinafter, the modified polyolefin wax will be described.

 The polyolefin wax that is the basis of the acid-grafted modified polyolefin wax is a polyethylene wax or polypropylene wax, which may be obtained by polymerizing olefins, or by thermally decomposing high molecular weight polyethylene or polypropylene. Although it may be obtained, an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms is particularly desirable. The α-olefin may be linear or branched, and may be substituted or unsubstituted. The α-olefin is preferably an α-olefin having 3 to 10 carbon atoms, more preferably propylene having 3 carbon atoms, 1-butene having 4 carbon atoms, 1-pentene having 5 carbon atoms, and carbon atoms. Examples thereof include 1-hexene, 4-methyl-1-pentene having 6 formulas, 1-octene having 8 carbon atoms, and particularly preferable examples include propylene, 1-butene, 1-hexene and 4-methyl-1-pentene. It is done.

   The method for producing the ethylene homopolymer or the copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms is not particularly limited. For example, a monomer such as ethylene or α-olefin may be used as a Ziegler / It is obtained by polymerization with a Natta catalyst or a metallocene catalyst. Among these catalysts, metallocene-based catalysts are preferable, and when the polyolefin used as the basis of the modified polyolefin wax is polyethylene, for the production of polyethylene, a metallocene compound of a transition metal selected from Group 4 of the periodic table, an organoaluminum oxy compound, and It is produced by using the following metallocene catalyst comprising an ionized ionic compound.

  <Metalocene Compound> The metallocene compound that forms the metallocene catalyst is a metallocene compound of a transition metal selected from Group 4 of the periodic table, and specific examples include compounds represented by the following general formula (1). .

M ¹ Lx (1) where M ¹ is a transition metal selected from Group 4 of the periodic table, x is a valence of the transition metal M ¹ , and L is a ligand.

Examples of the transition metal represented by M ¹ include zirconium, titanium, hafnium and the like.
L is a ligand coordinated to the transition metal M ^1, and at least one of the ligands L is a ligand having a cyclopentadienyl skeleton, and the ligand having this cyclopentadienyl skeleton. The ligand may have a substituent.

Examples of the ligand L having a cyclopentadienyl skeleton include a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, an n- or i-propylcyclopentadienyl group, n-, alkyl such as i-, sec- or t-butylcyclopentadienyl group, dimethylcyclopentadienyl group, methylpropylcyclopentadienyl group, methylbutylcyclopentadienyl group, methylbenzylcyclopentadienyl group, An alkyl-substituted cyclopentadienyl group; and an indenyl group, 4,5,6,7-tetrahydroindenyl group, a fluorenyl group, and the like.
The hydrogen of the ligand having a cyclopentadienyl skeleton may be substituted with a halogen atom or a trialkylsilyl group.

When the metallocene compound has two or more ligands having a cyclopentadienyl skeleton as the ligand L, the ligands having two cyclopentadienyl skeletons are ethylene, propylene. Or a substituted alkylene group such as isopropylidene or diphenylmethylene; a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group, or a methylphenylsilylene group.
Examples of ligands other than ligands having a cyclopentadienyl skeleton (ligands having no cyclopentadienyl skeleton) L include hydrocarbon groups having 1 to 12 carbon atoms, alkoxy groups, aryloxy groups, sulfones. Acid-containing group (—SO ₃ R ¹ ), halogen atom or hydrogen atom (where R ¹ is an alkyl group, an alkyl group substituted with a halogen atom, an aryl group, an aryl group substituted with a halogen atom, or an alkyl group) A substituted aryl group.

  <Example 1 of Metallocene Compound> When the metallocene compound represented by the general formula (1) has a transition metal valence of 4, for example, it is more specifically represented by the following general formula (2).

R ² _k R ³ _l R ⁴ _m R ⁵ _n M ¹ (2) where M ¹ is a transition metal selected from Group 4 of the periodic table, R ² is a group having a cyclopentadienyl skeleton (ligand ), R ³ , R ⁴ and R ⁵ are each independently a group (ligand) having or not having a cyclopentadienyl skeleton.
k is an integer of 1 or more, and k + l + m + n = 4.

Examples of metallocene compounds in which M ¹ is zirconium and contains at least two ligands having a cyclopentadienyl skeleton are given below.
Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium dichloride, bis (1-methyl-3-butylcyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (1, 3-dimethylcyclopentadienyl) zirconium dichloride and the like.
Among the above compounds, compounds in which the 1,3-position substituted cyclopentadienyl group is replaced with a 1,2-position substituted cyclopentadienyl group can also be used.

Another example of the metallocene compound is a group in which at least two of R ² , R ³ , R ⁴ and R ⁵ , for example, R ² and R ³ have a cyclopentadienyl skeleton in the general formula (2) ( A bridge type metallocene compound in which at least two groups are bonded via an alkylene group, a substituted alkylene group, a silylene group, a substituted silylene group, or the like. At this time, R ⁴ and R ⁵ are independently the same as the ligand L other than the ligand having the cyclopentadienyl skeleton described above.
Examples of such bridge-type metallocene compounds include ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium dichloride, methyl Examples include phenylsilylene bis (indenyl) zirconium dichloride.

When the polyolefin used as the basis of the modified polyolefin wax is polypropylene, it is a homopolymer of propylene obtained in the presence of a metallocene catalyst or a copolymer of propylene and ethylene or another α-olefin other than propylene.
The α-olefin is a 1-alkene having 4 to 10 carbon atoms, specifically 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and the like.
A homopolymer or copolymer of propylene obtained in the presence of a metallocene catalyst has an isotactic structure or a syndiotactic structure.
In the case of a propylene homopolymer or copolymer isotactic structure obtained in the presence of a metallocene catalyst, the isotactic pentad mmmm measured by ¹³ C-NMR is usually 90 to 99%, preferably 93 to 99%. It is.
In the case of a copolymer of propylene and ethylene or an α-olefin other than propylene, the content of the α-olefin other than ethylene or propylene in the copolymer is usually 1 to 20 mol%, preferably 1 to 10 mol%.
The metallocene catalyst used for the production of a homopolymer of propylene having an isotactic structure or a copolymer of propylene and ethylene or an α-olefin other than propylene is a periodic table of titanium, zirconium, hafnium, etc. It is a catalyst using a complex of a group -6 transition metal and a cyclopentadienyl group or a cyclopentadienyl derivative group.
In the metallocene catalyst, as the cyclopentadienyl derivative group, an alkyl substituent such as pentamethylcyclopentadienyl or a group in which two or more substituents are combined to form a saturated or unsaturated cyclic substituent is used. Typically, an indenyl group, a fluorenyl group, an azulenyl group, or a partial hydrogenated product thereof can be given.
Further, those in which a plurality of cyclopentadienyl groups are bonded by an alkylene group, a silylene group, a germylene group or the like are also preferably used.

When the homopolymer or copolymer of propylene obtained in the presence of the metallocene catalyst has a syndiotactic structure, the syndiotactic pentad fraction is usually 0.6 or more.
A crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more is observed at about 20.3 ppm in a 13 C-NMR spectrum measured with a 1,2,4-trichlorobenzene solution at 135 ° C. based on tetramethylsilane. This is a polypropylene having a syndiotactic pentad fraction of 0.6 or more, which is a value obtained by dividing the peak intensity divided by the sum of the peak intensity attributed to the methyl group of the propylene unit.
As a method for producing a polypropylene having a syndiotactic structure, propylene is polymerized by using a catalyst comprising an asymmetric ligand and a transition metal compound having an asymmetric ligand (Japanese Patent Laid-Open No. 2-41303 and J. Am. Chem. Soc ., 1988, 110, 6255-6256) are known.

  As a method for acid graft modification of the modified polyolefin wax used in the present invention, it can be prepared by a conventionally known method. For example, a raw material polyolefin wax and an unsaturated carboxylic acid or a derivative thereof or a sulfonate salt are mixed with an organic peroxide. Melt-knead in the presence of a polymerization initiator such as an oxide, or dissolve a raw material polyolefin wax and an unsaturated carboxylic acid or its derivative or sulfonate in an organic solvent to polymerize an organic peroxide or the like. It is obtained by adding an initiator and causing a graft reaction.

  Examples of unsaturated carboxylic acids or derivatives thereof used for acid graft modification include methyl acrylate, ethyl acrylate, butyl acrylate, acrylate-sec-butyl, isobutyl acrylate, propyl acrylate, isopropyl acrylate, acrylic 2-octyl acid, dodecyl acrylate, stearyl acrylate, hexyl acrylate, isohexyl acrylate, phenyl acrylate, 2-chlorophenyl acrylate, diethylaminoethyl acrylate, 3-methoxybutyl acrylate, diethylene glycol ethoxy acrylate Rate, acrylic acid esters such as acrylic acid-2,2,2-trifluoroethyl; methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylate-sec-butyl, isomethacrylate Butyl, propyl methacrylate, isopropyl methacrylate, -2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, stearyl methacrylate, hexyl methacrylate, decyl methacrylate, phenyl methacrylate, 2-chlorohexyl methacrylate, methacryl Methacrylic acid esters such as diethylaminoethyl acetate, methacrylic acid-2-hexylethyl, methacrylic acid-2,2,2-trifluoroethyl; ethyl maleate, propyl maleate, butyl maleate, diethyl maleate, dipropyl maleate , Maleic acid esters such as dibutyl maleate; fumaric acid esters such as ethyl fumarate, butyl fumarate, dibutyl fumarate; maleic acid, fumaric acid, itaconic acid, crotonic acid, nadic acid Dicarboxylic acids such as methyl hexahydrophthalic acid; maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, glutaconic acid, and the like anhydride such as nadic.

In the case of modification with an unsaturated carboxylic acid or a derivative thereof, the modified polyolefin wax modified with an acid graft has an amount of modification of 1 to 100 mgKOH / g, preferably 3 to 60 mgKOH / g in terms of acid value in terms of KOH titration. More preferably, it is 5 to 50 mgKOH / g.
When the modification amount is within the above range, the compatibility between the modified polyolefin wax and the epoxy is good, so that the resin composition does not adhere to the transfer molding machine or the cylinder of the injection molding machine, and the molding can be performed stably. There are few bleeds to various members such as lead frames, and excellent adhesion, solder crack resistance, moisture resistance reliability, and continuous formability.

  The number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of the modified polyolefin wax used in the present invention is from 400 to 5,000, preferably from 5,000 to 4,000, more preferably from 7.0 to 4-4. In the range of 1,000. When the number average molecular weight (Mn) is in the above range, the compatibility between the modified polyolefin wax and the epoxy is good, so there is little bleeding to various members such as lead frames, adhesion, solder crack resistance, and moisture resistance reliability. Excellent in moldability and continuous formability.

  The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of the modified polyolefin wax is 1.5 to 4.5, preferably 1. It is in the range of 6 to 4.0, more preferably 1.7 to 3.5. When Mw / Mn is in the above range, fluidity at the time of molding and bleed to various members such as a lead frame are small, and adhesion, solder crack resistance, moisture resistance reliability, and continuous moldability are excellent.

   In addition, a weight average molecular weight (Mw) and a number average molecular weight (Mn) are the values of polyethylene conversion by gel permeation chromatography (GPC), and the measurement by GPC is the conditions of temperature: 140 ° C., solvent: orthodichlorobenzene. Done under.

The intrinsic viscosity [η] of the modified polyolefin wax measured in decalin at 135 ° C. is 0.04 to 0.47 dl · g ⁻¹ , preferably 0.03 to 0.47 dl · g ⁻¹ , more preferably 0.04. ~0.30dl · g ^-1, even more preferably it is preferably in the range of 0.05~0.18dl · g ^-1. When the intrinsic viscosity [η] is in the above range, the compatibility between the modified polyolefin wax and the epoxy is good, so there is little bleeding to various members such as a lead frame, adhesion, solder crack resistance, and moisture resistance reliability. Excellent continuous formability.

   The melting point of the modified polyolefin wax measured with a differential scanning calorimeter (DSC) is in the range of 65 to 130 ° C, preferably 70 to 120 ° C, more preferably 80 to 110 ° C. When the melting point is in the above range, fluidity during molding and bleed to various members such as a lead frame are small, and adhesion, solder crack resistance, moisture resistance reliability, and continuous moldability are excellent.

The density measured by the density gradient tube method of the modified polyolefin wax is 850 to 980 kg / m ³ , preferably 870 to 970 kg / m ³ , more preferably 900 to 940 kg / m ³ . When the density is in the above range, the compatibility between the modified polyolefin wax and the epoxy is good, so there are few bleeds to various members such as a lead frame, adhesion, solder crack resistance, moisture resistance reliability, and continuous moldability. Excellent.

The penetration of the modified polyolefin wax is desirably 30 dmm or less, preferably 25 dmm or less, more preferably 20 dmm or less, and even more preferably 15 dmm or less. When the penetration is in the above range, the crystallinity of the polyolefin wax tends to be high, and the solder crack resistance is excellent.
The penetration can be measured according to JIS K2207.

  These modified polyolefin waxes may be used singly or as a mixture of a plurality of modified polyolefin waxes, or may be used in combination with other waxes usually used as mold release agents.

The compounding quantity of a mold release agent is 0.03-1.00 weight part of mold release agents (C) with respect to a total of 100 weight of a thermosetting resin (A) and an inorganic filler (B), Preferably It is 0.05-0.8 weight part, More preferably, it is 0.2-0.7 weight part.
If the compounding amount of the release agent is within the above range, the flowability of the resin composition in the cylinder of the transfer molding machine or the injection molding machine becomes appropriate, so that the molding can be performed stably. No bleed, excellent adhesion, solder crack resistance, moisture resistance reliability, and continuous formability.

In addition, when the modified polyolefin wax used in the present invention is a modified polyethylene wax, the material is sufficiently dispersed when it is formed into a molding material, so that the kneadability is good, and the adhesion to the frame and the moisture resistance reliability during molding are good. Excellent performance.
Therefore, at the time of molding, a lubricant effect is exhibited, and fluidity, filling properties, mold release properties, adhesion to the frame, and moisture resistance reliability are improved.

In addition to the above, the resin composition of the present invention may contain a silane coupling agent, a flame retardant, a colorant, a low stress agent, and the like as necessary.
All these materials are heated and kneaded with a heating kneader or a hot roll, and then cooled and pulverized to obtain the intended resin composition, which can be used as a semiconductor encapsulant.

  Hereinafter, the excellent effect of the present invention will be described by way of examples, but the present invention is not limited to these examples.

In the following examples, the physical properties of the wax (release agent) were measured as follows.
<Acid value>
It measured according to JIS K5902.
<Number average molecular weight (Mn), weight average molecular weight (Mw)>
The number average molecular weight (Mn) and the weight average molecular weight (Mw) are obtained from GPC measurement. The measurement was performed under the following conditions. The number average molecular weight (Mn) and the weight average molecular weight (Mw) were determined by preparing a calibration curve using commercially available monodisperse standard polystyrene and calculating the molecular weight based on the following conversion method.
Apparatus: Gel permeation chromatograph Alliance GPC2000 (manufactured by Waters)
Solvent: o-dichlorobenzene column: TSKgel column (manufactured by Tosoh Corporation) x 4
Flow rate: 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution temperature: 140 ° C.
Molecular weight conversion: PE conversion / general-purpose calibration method For the calculation of general-purpose calibration, the coefficient of the Mark-Houwink viscosity equation shown below was used.
Coefficient of polystyrene (PS): KPS = 1.38 × 10 ⁻⁴ , aPS = 0.70
Coefficient of polyethylene (PE): KPE = 0.06 × 10 ⁻⁴ , aPE = 0.70
<Intrinsic viscosity [η]>
Measured according to ASTM D1601.
<Melting point>
It measured using the differential scanning calorimeter (DSC) [DSC-20 (made by Seiko Denshi Kogyo Co., Ltd.)]. First, the measurement sample was once heated to 200 ° C. and held for 5 minutes, and then immediately cooled to room temperature. About 10 mg of this sample was subjected to DSC measurement in the temperature range from −20 ° C. to 200 ° C. under the temperature rising rate of 10 ° C./min. The endothermic peak value of the curve obtained from the measurement results was taken as the melting point.
<Density>
It was measured according to the density gradient method of JIS K7112.
<Penetration>
It measured according to JIS K2207.
[Synthesis Example 1] (Synthesis of Polyolefin Wax (1)) Using a metallocene catalyst, an ethylene / propylene copolymer (polyolefin wax (1)) was synthesized as follows.

A stainless steel autoclave having an internal volume of 2 liters, which was sufficiently purged with nitrogen, was charged with 940 ml of hexane and 60 ml of propylene, and hydrogen was introduced until the pressure reached 0.27 MPa (gauge pressure).
Next, after raising the temperature in the system to 150 ° C., 0.3 mmol of triisobutylaluminum, 0.004 mmol of triphenylcarbenium tetrakis (pentafluorophenyl) borate, (t-butylamido) dimethyl (tetramethyl-η ⁵⁾ Polymerization was initiated by injecting 0.02 mmol of -cyclopentadienyl) silane titanium dichloride (Sigma-Aldrich) with ethylene.
Thereafter, only ethylene was continuously supplied to keep the total pressure at 2.9 MPa (gauge pressure), and polymerization was carried out at 150 ° C. for 20 minutes.
After the polymerization was stopped by adding a small amount of ethanol into the system, unreacted ethylene and propylene were purged. Furthermore, the obtained polymer solution was dried overnight at 100 ° C. under reduced pressure to obtain a polyolefin wax (1) having physical properties shown in Table 1.

   [Modification Example 1] 200 g of polyolefin wax (1) was placed in 1000 ml of toluene and completely dissolved in a pressure-resistant autoclave at 160 ° C., then 3.5 g of maleic anhydride at 70 ° C. and ditertiary butyl peroxide at room temperature (Japan) 6.0 g of Perfume D (manufactured by Yushi Co., Ltd.) was simultaneously supplied over 1.5 hours, and after aging for 1 hour, the solvent was removed with a vacuum of 1 mmHg, and the modified polyolefin wax (1 )

  [Synthesis Example 2] (Synthesis of polyolefin wax (2)) Using a metallocene catalyst, an ethylene / butene copolymer (polyolefin wax (2)) was synthesized as follows. In the synthesis of Synthesis Example 1, synthesis was performed in the same manner as in Synthesis Example 1 except that 935 ml of hexane and 65 ml of 1-butene were used instead of propylene, and hydrogen was 0 and 15 MPa (gauge pressure). 2) was obtained.

  [Modification Example 2] 200 g of 30200B was placed in 1000 ml of toluene and completely dissolved in a pressure-resistant autoclave at 160 ° C., then 7.0 g of maleic anhydride at 70 ° C. and ditertiary butyl peroxide at room temperature (manufactured by NOF Corporation, Perbutyl D) 12.0 g was simultaneously supplied over 1.5 hours, and after aging for 1 hour, the solvent was removed at a vacuum of 1 mmHg to obtain a modified polyolefin wax (2) having the physical properties shown in Table 1. .

[Synthesis Example 3] (Synthesis of Polyolefin Wax (3)) Using a metallocene catalyst, an ethylene / propylene copolymer (polyolefin wax (3)) was synthesized as follows.
Synthesis was carried out in the same manner as in Synthesis Example 1 except that 960 ml of hexane and 40 ml of propylene were charged and hydrogen was changed to 0.08 MPa (gauge pressure) in the synthesis of Synthesis Example 1 to obtain a polyolefin wax (3).

[Modification 3] An oxidation reaction was carried out in a 2 L autoclave (equipped with a thermometer, pressure gauge, stirrer, gas introduction pipe, and gas exhaust pipe).
After 500 g of polyethylene wax (2) was melted and the internal temperature reached 165 ° C., the stirrer was set to 300 min ⁻¹ and air was introduced into the melt at 1.2 L / min. 0.69 MPa was indicated.
While introducing air, the reaction temperature was maintained at 165 ° C., the stirring rate was maintained at 300 min ⁻¹ , the pressure was maintained at 0.69 MPa, the reaction was terminated after 6 hours, and a modified polyolefin wax (3) having physical properties shown in Table 1 was obtained. Obtained.

[Synthesis Example 4] (Synthesis of Polyolefin Wax (4)) Using a metallocene catalyst, an ethylene / propylene copolymer (polyolefin wax (4)) was synthesized as follows.
Synthesis was performed in the same manner as in Synthesis Example 1 except that 968 ml of hexane and 32 ml of propylene were charged and hydrogen was changed to 0.08 MPa (gauge pressure) in the synthesis of Synthesis Example 1 to obtain a polyolefin wax (4).

[Modification Example 4] A modified polyolefin wax (4) having the physical properties shown in Table 1 was subjected to an oxidation reaction in the same manner as Modification Example 3 except that the polyolefin wax (4) was used instead of the polyolefin wax (3). Got.
[1105A] A modified polyolefin wax (manufactured by Mitsui Chemicals, 1105A) produced with a Ziegler catalyst and modified with maleic anhydride graft and having the physical properties shown in Table 1.
[2203A] A modified polyolefin wax (manufactured by Mitsui Chemicals, 2203A) produced with a Ziegler catalyst and modified with maleic anhydride graft and having the physical properties shown in Table 1.

[Example 1]
All raw materials were mixed by a Henschel mixer at the weight ratio shown in Example 1 in Table 2, then kneaded with a kneader, roll, etc. at a temperature of 90 ° C., cooled and pulverized to obtain a sealing material.
Using this material, spiral flow, gelation time, solder crack resistance, continuous formability, adhesion, and moisture resistance stability were evaluated. Hereinafter, each evaluation method is shown.
<Spiral flow>
Using a mold with a spiral inside, transfer molding was performed at a mold temperature of 150 ° C. and an effective pressure of 70 kgf / cm ² , and the length that flowed in the mold when cured for about 180 seconds was measured. did.
<Gelification time>
2 g of the resin was placed on a hot plate at 180 ° C., spread to about 25 mm square using a spatula and rubbed against the hot plate, and then the time for the resin to harden and peel off from the hot plate was measured.
<Solder crack resistance>
60pQFP package (package size 12x18mm, thickness 1.5mm, chip size 8x8mm, gate size 0.3x0.3mm) injection molded product absorbs moisture for 192 hours in an atmosphere of 30 ° C and 60% relative humidity Thereafter, a solder crack resistance test by IR reflow (220 ° C.) was performed. The number of samples with cracks relative to the total number of samples was measured.

<Continuous formability>
Judgment was made based on whether or not the injection molding of 60 pQFP package (same as above) can be performed continuously for 10 hours or more.
<Adhesion>
The ratio of the number of packages in which internal peeling occurred to the total number of packages after observing the packages with an ultrasonic flaw detector after molding a 60 pQFP package (same as above) and leaving it in an environment of 121 ° C. and 100% RH for 48 hours.
<Moisture resistance stability>
After molding the 60pQFP package (same as above), it was left in an environment of 85 ° C. and 85% RH for 24 hours, and then immersed in a solder bath at 260 ° C. for 10 seconds.
Next, this package was subjected to PCT treatment at 125 ° C. and 2.3 atm, and expressed as a treatment time until the defect rate reached 50%.
All 60pQFP package molding was performed by injection molding, with a mold temperature of 180 ° C., an injection time of 10 seconds, and a curing time of 60 seconds. Post-curing was performed at 180 ° C. for 3 hours.
Table 3 shows the results of evaluation by the above evaluation method.

[Example 2]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 2 in Table 2 were used.
The results are shown in Table 3.

[Example 3]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 3 in Table 2 were used. The results are shown in Table 3.

[Example 4]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 4 in Table 2 were used. The results are shown in Table 3.

[Example 5]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 5 in Table 2 were used. The results are shown in Table 3.

[Example 6]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 6 in Table 2 were used. The results are shown in Table 3.

[Example 8]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 7 in Table 2 were used. The results are shown in Table 3.

[Example 8]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Example 8 in Table 2 were used. The results are shown in Table 3.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Comparative Example 1 in Table 2 were used. The results are shown in Table 3.

[Comparative Example 2]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Comparative Example 2 in Table 2 were used. The results are shown in Table 3.
[Comparative Example 3]
The same procedure as in Example 1 was performed except that the type and amount of wax shown in Comparative Example 3 in Table 2 were used. The results are shown in Table 3.

  Use of the resin composition of the present invention is useful as a semiconductor encapsulant because it has continuous moldability, excellent solder crack resistance to various members such as lead frames, adhesion, and moisture stability.

Claims (5)

A resin composition containing a thermosetting resin (A), an inorganic filler (B) and a release agent (C), wherein the release agent (C) has a melting point of 65 measured by a differential scanning calorimeter (DSC). A resin composition characterized by being a modified polyolefin wax in a range of ˜130 ° C. and subjected to acid graft modification.   2. The resin composition according to claim 1, wherein the acid value of the modified polyolefin wax is 1 to 100 KOHmg / g.   2. The resin composition according to claim 1, wherein the modified polyolefin wax is obtained by acid graft modification of a polyolefin wax produced with a metallocene catalyst.   The resin composition of Claim 1 which contains 0.03-1.00 weight part of mold release agents (C) with respect to a total of 100 weight of a thermosetting resin (A) and an inorganic filler (B).   The semiconductor sealing material containing the resin composition in any one of Claims 1-4.