JP2009275108A - Semiconductor-sealing resin composition, method for producing the same and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor-sealing resin composition excellent in mechanical strengths and a burr-removing property in a small-sized semiconductor package, and also in moldability, preservation stability and flame retardance. <P>SOLUTION: This semiconductor-sealing resin composition is used as a sealing material of a semiconductor device having a size smaller than the following dimension (x). The semiconductor-sealing resin composition is provided by using the following components (A) to (D). (x): 2 mm length ×2 mm width ×1 mm height. (A): A metal hydroxide compound having a 1 to 20 μm mean particle diameter and a 1 to 2 m<SP>2</SP>/g specific surface area. (B): An inorganic filler other than the above (A). (C): An epoxy resin. (D): A molten mixture obtained by melting and mixing a phenol novolak resin with a basic curing accelerator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition for encapsulating a semiconductor excellent in reliability such as moldability, deburring workability, and flame retardancy, and a method for producing the same, and a semiconductor element using the same The present invention relates to a semiconductor device formed by sealing.

  2. Description of the Related Art Conventionally, semiconductor elements such as IC and LSI are resin-sealed using a resin composition to form a semiconductor device. In recent years, electronic devices that have been reduced in size and thickness, such as mobile phones, have been widely used, and accordingly, semiconductor devices themselves that have been downsized are also frequently used. An important characteristic when encapsulating such a small semiconductor package with a resin composition is package formability. For example, since a semiconductor package is a small product, since a large number of packages are usually molded with the same mold, a good cycle and a possibility of a molding cycle in a short time are required.

  However, in order to improve the fluidity, for example, when a low molecular weight resin is used, the curability is lowered. Therefore, in order to increase the curability, the blending amount of the curing accelerator is increased or the amount of the resin is increased. Although it is conceivable to increase the functionality, this time, there arises a problem that the storage stability of the resin composition as the sealing material is lowered. As described above, when the fluidity is insufficient or the mechanical strength is low, in a small package, there is a problem in that corner chipping, insufficient filling of a sealing material, and the like increase relative to the package size. It was.

  Also, if the thickness of the package itself is reduced like a small package, the thickness of the burr formed at the time of molding becomes relatively large with respect to the thickness of the package. As a result, a large force is applied when removing the burr, and the burr is removed. In some cases, the part is torn off to form a deep recess, or the package may be chipped. If the mechanical strength is extremely high, interface peeling between the lead frame and the sealing resin portion occurs, and there is a problem that the electrical reliability of the semiconductor device is lowered.

  On the other hand, in semiconductor devices, flame retardancy is also required, and in order to impart the above flame retardancy, conventionally, various flame retardants have been blended into sealing materials. From such viewpoints, there is a demand for imparting flame retardancy by using a flame retardant that does not contain halogen atoms or toxic elements. For example, the use of a metal hydroxide compound has attracted attention.

However, since the use of the metal hydroxide compound has an adverse effect on curability in the resin composition for semiconductor encapsulation, for example, the metal hydroxide compound is mixed with other inorganic fillers in advance, It has been proposed to improve the curability by using a curing accelerator such as a compound or a diazabicycloalkene compound (see Patent Document 1).
JP 2006-241411 A

  However, the method as described in Patent Document 1 has a certain degree of effectiveness for a conventional large-sized package, but sufficient hardening is achieved in a semiconductor package with a smaller size. It's hard to say that it has the nature.

  The present invention has been made in view of such circumstances, and is a resin for semiconductor encapsulation that is excellent in mechanical strength and burr removal property, and also excellent in moldability, storage stability, and flame retardancy in a small semiconductor package. It is an object of the present invention to provide a composition, a manufacturing method thereof, and a semiconductor device using the composition.

In order to achieve the above object, the present invention provides a semiconductor sealing resin composition used as a sealing material for a semiconductor device having a size of the following dimension (x) or less, and includes the following (A) to ( The resin composition for semiconductor encapsulation using the component D) is the first gist.
(X) 2 mm long × 2 mm wide × 1 mm height.
(A) A metal hydroxide compound having an average particle diameter of 1 to 20 μm and a specific surface area of 1 to ² m ² / g.
(B) An inorganic filler other than the component (A).
(C) Epoxy resin.
(D) A molten mixture obtained by melting and mixing a phenol novolac resin and a basic curing accelerator.

  And this invention is a manufacturing method of the resin composition for semiconductor sealing used as a sealing material of the semiconductor device of the magnitude | size below the said dimension (x), Comprising: A phenol novolak resin and a basic hardening accelerator previously A second gist is a method for producing a resin composition for semiconductor encapsulation, in which a melt mixture is prepared by melt-mixing and then the melt mixture and the components (A) to (C) are melt-kneaded.

Further, the present invention provides a semiconductor device having a size equal to or smaller than the following dimension (x) obtained by encapsulating a semiconductor element using the semiconductor sealing resin composition of the first aspect. And
(X) 2 mm long × 2 mm wide × 1 mm height.

  The present inventors have provided an epoxy resin composition for semiconductor encapsulation that is excellent in mechanical strength, burrs removal property, and excellent in moldability, storage stability, and flame retardancy when sealing a small semiconductor package. A series of studies were repeated to obtain this. As a result, in order to improve curability and storage stability, instead of simply blending each component as in the past, a phenol novolac resin and a basic curing accelerator are melted and mixed in advance to produce a molten mixture. The inventors have found that the use of this molten mixture and other blending components is effective. That is, since a salt is formed by melt-mixing a phenol novolac resin and a basic curing accelerator, salt formation between the basic curing accelerator and the metal hydroxide compound hardly occurs, and the basic curing accelerator. Is stabilized by phenol novolac resin. For this reason, the reactivity at low temperature is lowered and the storage stability is improved. On the other hand, when the temperature is high, the curing accelerator is present in the vicinity of the phenol group which is a reactive group, so that the reactivity becomes high. For this reason, the present inventors have found that it is easy to remove the formed burrs and that excellent reliability, moldability at the time of resin sealing, and storage stability can be obtained.

  As described above, the present invention is a resin composition for encapsulating a semiconductor device having a size of the specific dimension (x) or less, and together with a specific metal hydroxide compound [component (A)], a phenol novolac resin and It is the resin composition for semiconductor sealing using the molten mixture [(D) component] formed by melt-mixing a basic hardening accelerator. For this reason, it is possible to obtain a highly reliable semiconductor device with excellent flame retardancy and easy removal of the generated burrs without causing deterioration of moldability and storage stability.

  When a diazabicycloalkene compound is used as the basic curing accelerator, since the basicity is high, the curing acceleration is very excellent. However, when a metal hydroxide compound is used in combination, the metal hydroxide compound may be eluted and the electrical reliability may be deteriorated. Therefore, the content ratio of the basic curing accelerator with respect to the metal hydroxide compound Is set to a specific ratio (for example, 1 to 5% by weight), it is excellent in both curability and storage stability, and elution of the metal hydroxide compound can be suppressed.

  Furthermore, when a mercapto group-containing silane coupling agent is used, adhesion to a lead frame having a surface noble metal layer is improved by plating or the like.

  Then, together with a phenol novolac resin and a basic curing accelerator, the above-mentioned mercapto group-containing silane coupling agent is further blended, and when a molten mixture obtained by previously melt-mixing these blended components is used, a surface noble metal layer is formed by plating or the like. Adhesiveness to the lead frame is improved and good storage stability is obtained.

  Such a resin composition for encapsulating a semiconductor is prepared by previously melting and mixing a phenol novolak resin and a basic curing accelerator to prepare a molten mixture, and then mixing the molten mixture with a specific metal hydroxide compound [(A). Component], inorganic filler [component (B)] and epoxy resin [component (A)] are melt-kneaded. For this reason, the phenol novolak resin and the basic curing accelerator are likely to form a salt, and the basic curing accelerator is stabilized, so that the reactivity at low temperature is reduced and the storage stability is good. As a result, the adverse effect on the metal hydroxide compound is also suppressed. Therefore, a sealing material having an excellent balance between storage stability and curability can be obtained.

  Next, embodiments of the present invention will be described in detail.

In the present invention, a semiconductor device in which a semiconductor element is resin-sealed is intended to have a size equal to or smaller than the following dimension (x).
(X) 2 mm long × 2 mm wide × 1 mm height.

  And the resin composition for semiconductor sealing of this invention is a specific metal hydroxide compound (A component), inorganic fillers (B component) other than the said A component, an epoxy resin (C component), and a phenol novolak. It is obtained by using a molten mixture (component D) obtained by melt-mixing a resin and a basic curing accelerator, and is usually used in the form of a powder or a tablet obtained by tableting this.

  The specific metal hydroxide compound (component A) is a hydroxide or oxide hydrate of metals other than alkali metals.

The specific surface area of the metal hydroxide compound must be 1-2 m ² / g. That is, by setting the specific surface area within the above range, it is possible to prevent the curability from being lowered and to have excellent flame retardancy. The said specific surface area can be calculated | required, for example using a nitrogen adsorption method (BET method), and can be measured using the measuring apparatus according to JIS-Z-8830.

  Moreover, the average particle diameter of the said metal hydroxide compound must be 1-20 micrometers. That is, by setting the average particle diameter within the above range, the mechanical strength is maintained and a highly reliable package can be obtained. The average particle diameter can be derived by, for example, using a sample arbitrarily extracted from the population and measuring it using a laser diffraction / scattering particle size distribution measuring apparatus.

  Many of the above metal hydroxide compounds have alkalinity, lower the curability of the curing agent having acidity, and even if it is a curing agent having a phenolic hydroxyl group, the effect is seen. By setting the surface area small so as to be in a specific range, it is possible to reduce the influence on curability.

  And, the specific surface area affects the water release rate during combustion of the metal hydroxide compound, the larger the specific surface area, the easier the water release occurs, and the temperature drop and the air are efficiently blocked, Flame retardancy is improved. However, when the specific surface area is increased, the viscosity of the resin composition is increased and the fluidity is lowered, so that problems during molding such as poor filling are likely to occur. As a result of taking such points into consideration, by setting the specific surface area within the specific range, a balance between flame retardancy and moldability is achieved.

  Examples of the metal hydroxide compound include aluminum, gallium, indium, thallium, group 14 lead, semimetal element tin, group 15 semimetal bismuth, and transition metal, which are typical metals of group 13 of the periodic table. Examples include Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, etc., Group 2 alkaline earth elements beryllium, magnesium, calcium, strontium, barium, and the like.

  In particular, among the above metals, since alkaline earth elements such as magnesium are easily dissolved in water, it is preferable to use those whose surfaces are covered with a hydrophobic material. Magnesium has a high water release temperature and is excellent in thermal stability as a hydroxide. However, since the release of water occurs at a high temperature, it is insufficient in terms of flame retardancy. Therefore, the combined use with other metal hydroxide compounds having a low water release temperature is preferable.

  Of the metal hydroxide compounds, aluminum hydroxide is preferably used in consideration of the relatively low water release temperature and the large endothermic amount per unit weight.

  As described above, the average particle diameter of the metal hydroxide compound is 1 to 20 μm, more preferably 2 to 15 μm, and particularly preferably 3 to 10 μm. That is, if an average particle diameter is less than a lower limit, the viscosity of a resin composition will become high and fluidity | liquidity will fall. Further, if the average particle diameter exceeds the upper limit value, even in a small semiconductor package, clogging at the gate portion, pinching between metal wires, deformation of the wires, and the like occur.

  In addition, the said metal hydroxide compound is soft compared with the inorganic filler which is metal oxides, such as a silica powder generally used, and has the effect which deform | transforms and will block | close a flow path if it pinches | interposes in the clearance gap between mold surfaces. For this reason, the length of the generated burr is shortened, and a large amount of metal hydroxide compound is present on the die mating surface. Therefore, since the mechanical strength of the burrs is reduced, the burrs can be efficiently removed, and only the resin component is filtered to reduce the filler content in the burrs. Removal is easy.

  Furthermore, the maximum particle size of the metal hydroxide compound is preferably set to 64 μm or less. By setting in this way, there is a tendency that the possibility of being caught in the gap of the fluidized portion is reduced. The maximum particle diameter can be derived, for example, by measuring using a laser diffraction / scattering particle size distribution measuring apparatus, as with the average particle diameter.

  The content of the specific metal hydroxide compound (component A) is preferably set to 5 to 20% by weight, more preferably 7 to 15% by weight, based on the entire resin composition. That is, by setting the content within the above range, a product having an excellent molded appearance can be obtained. And when there is too much said content, it may produce a bubble on the surface of a molding due to the water which generate | occur | produces at the time of shaping | molding. On the other hand, if the content is too small, the flame retardancy tends to decrease.

  Examples of inorganic fillers (component B) other than the component A used together with the component A include silica powder, alumina powder, quartz glass powder, and talc. These may be used alone or in combination of two or more.

  As the inorganic filler (component B), in applications that require high thermal conductivity, alumina powder, silica powder, especially crystalline silica powder or crushed powder thereof (hereinafter referred to as “crushed crystal silica powder”) is used. It is preferable to use it. Furthermore, in order to improve the fluidity | liquidity of resin, it is still more preferable to use what removed the grinding | polishing corner of the powder. On the other hand, for the purpose of lowering the linear expansion coefficient, it is preferable to use silica powder that has been melted and made amorphous (hereinafter referred to as “fused silica powder”). And when improving the fluidity | liquidity of resin, the thing which sprayed and melted the silica powder in the flame and made spherical shape is used preferably.

  The average particle size of the inorganic filler (component B) is preferably 5 to 30 μm, particularly preferably 5 to 25 μm. That is, if the average particle size is less than the lower limit value, the fluidity of the resin composition decreases, and if it exceeds the upper limit value, clogging at the mold gate due to particles having a large particle size tends to occur. is there. Furthermore, the maximum particle size should be 64 μm or less. In the case of small semiconductor packages, the appearance after molding is excellent and smooth, poor flow due to the trapping of the inorganic filler on the mold gate, and sandwiched between wires It is particularly preferable because the effect of suppressing the occurrence of deformation of the wire due to the wire and voids in the wire portion is obtained. In the present invention, the average particle size and the maximum particle size can be derived, for example, by using a sample arbitrarily extracted from the population and measuring it using a laser diffraction / scattering particle size distribution analyzer. .

  And it is preferable to set content of the said inorganic filler (B component) in the range of 60 to 80 weight% of the whole resin composition. Furthermore, it is preferable that the total content of the inorganic material including the specific metal hydroxide compound (component A) and the inorganic material such as carbon black is set in the range of 70 to 85% by weight of the entire resin composition. . Thus, by setting so that the whole inorganic substance may become the said range, it is excellent in the mechanical strength of resin, and fluidity | liquidity etc. become favorable. That is, if the content of the entire inorganic material is too small, there is a tendency to cause problems such as a decrease in mechanical strength and the generation of stress due to an increase in the linear expansion coefficient. If the content is too large, the viscosity increases and the moldability decreases. This is because the tendency to do is seen. Thus, the more inorganic filler (B component) is superior in flame retardancy and the linear expansion coefficient and the like are low, so the stress of the molded product is low, for example, unnecessary force is applied to the semiconductor element, Separation at the interface between the semiconductor element and the lead frame and the sealing resin hardly occurs. However, when there are too many inorganic materials, the viscosity of a resin composition will rise and moldability will fall. In particular, in the case of a small semiconductor package such as the present invention, not only the height of the flow path but also the flow path width is narrowed in the mold, so that the amount of inorganic material is less than that used for a large semiconductor package. Things are used.

  Examples of the epoxy resin (C component) used together with the A component and the B component include various epoxy resins such as cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, biphenyl type epoxy resin, and bromination. An epoxy resin etc. are mention | raise | lifted. These may be used alone or in combination of two or more. Especially, it is preferable to use the thing of the range whose epoxy equivalent is 185-205 from the point of a moldability, More preferably, it is 190-200. That is, if the epoxy equivalent is less than the lower limit, the fluidity is lowered, and if it exceeds the upper limit, the curability tends to be lowered. Furthermore, it is preferable to use a softening point in the range of 50 to 80 ° C., more preferably 55 to 75 ° C., from the viewpoint of the handleability and moldability of the resin. That is, if the softening point is too low, the resin composition tends to be blocked, and if the softening point is too high, the fluidity of the resin composition tends to decrease. Specifically, it is particularly preferable to use a cresol novolac type epoxy resin having an epoxy equivalent and a softening point in the above range.

  A melt mixture (component D), which is used together with the epoxy resin (component C) and melt-mixed with a phenol novolac resin and a basic curing accelerator, prepares a phenol novolac resin and a basic curing accelerator, It was prepared by melt-mixing in advance. The phenol novolac resin is obtained by reacting a compound having a phenolic hydroxyl group such as phenol or naphthol with an aldehyde, a ketone or the like in an acidic atmosphere. In a broad sense, a phenol compound and a methoxymethylene group, etc. The phenol aralkyl resin obtained by making it react with the aromatic compound which has this is also included.

  In the present invention, since the semiconductor device to be sealed is a small package having the dimension (x), it is important to increase the crosslinking density of the resin, and a novolak type phenol formaldehyde resin having a low phenolic hydroxyl group equivalent Is preferably used. If the phenolic hydroxyl group equivalent is low, even if it has a low molecular weight, it will have 3 or more phenolic hydroxyl groups, so that the resin composition can be obtained using a low molecular weight compound without greatly deteriorating the cured product properties. It is also possible to reduce the viscosity of the resin and ensure the fluidity of the resin.

  As said phenol novolak resin, it is preferable to use the thing of 100-200 phenolic hydroxyl equivalent, and it is preferable to use the thing of 100-150 especially from a sclerosing | hardenable viewpoint. The softening point is preferably 50 to 110 ° C.

  The phenol novolac resin is not limited to the phenol novolac resin having the physical properties described above, and other phenol novolac resins can be used or used together if necessary.

  The basic curing accelerator is a compound having alkalinity when dissolved in water. In general, the degree of basicity is indicated by the dissociation multiplier pKa. When the value of the dissociation multiplier pKa is large, the basicity is high. And the basic hardening accelerator as used in the field of this invention means that whose dissociation multiplier pKa is 5 or more. Therefore, for example, triphenylphosphine having a dissociation multiplier pKa of 3 is naturally not included in the basic curing accelerator referred to in the present invention. Since the value of the dissociation multiplier pKa may differ depending on the solvent used, the value measured and evaluated in dimethyl sulfoxide (DMSO) is used in the present invention.

  Examples of the basic curing accelerator include imidazole compounds and tertiary amine compounds.

  Specific examples of the imidazole compound include 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-methylimidazole, and 2-ethyl-4-methyl. Imidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenyl-4,5-diphenylimidazole, 2,4-dimethylimidazole, Butylimidazole, 2-heptadecenyl-4-methylimidazole, 2-undecenylisoimidazole, 1-vinyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-propyl-2-methylimidazole, 1-guanaminoethyl -2 Methylimidazole, addition product of imidazole and trimellitic acid, addition product of imidazole and 2-n-heptadecyl-4-methylimidazole, 2-methyl-4,5-diphenylimidazole, 2,3,5-triphenylimidazole 2-styrylimidazole, 1- (dodecylbenzyl) -2-methylimidazole, 2- (2-hydroxy-4-tert-butylphenyl) -4,5-diphenylimidazole, 2- (2-methoxyphenyl) -4 , 5-diphenylimidazole, 2- (3-hydroxyphenyl) -4,5-diphenylimidazole, 2- (p-dimethylaminophenyl) -4,5-diphenylimidazole, 2- (2-hydroxyphenyl) -4, 5-diphenylimidazole, 1,4-di (4,5-diphenyl-2 Imidazole) -benzene, 2-naphthyl-4,5-diphenylimidazole, 2-p-methoxystyrylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl -4-methylimidazole, 2,4-diamino-6- {2'-methylimidazolyl- (1) '}-ethyl-s-triazine, 2-methylimidazole-isocyanuric acid adduct, 2-phenylimidazole-isocyanate Nuric acid adduct, 2,4-diamino-6 {2'-methylimidazolyl- (1) '} ethyl-s-triazine isocyanuric acid adduct, 2-alkyl-4-formylimidazole, 2,4- Dialkyl-5-formylimidazole, 1-cyanoethyl-2-phenylimi Dazolium trimellitate, 1- [3- (trimethoxysilyl) propyl] imidazole, reaction product of imidazole not substituted with hydrogen at the 1-position and a silane coupling agent having an epoxy group, N, N'- Bis- (2-methylimidazolyl-1-ethyl) -urea, N, N ′-(2-methylimidazolyl- (1) -ethyl) -adipoyldiamide, 2,4-dialkylimidazole-5-dithiocarboxylic acid Imidazole tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, 1-cyanoethyl-2-ethyl-4-methylimidazole tetraphenylborate, 1-cyanoethyl-2-undecylimidazole tetraphenylborate 1-cyanoethyl-2-phenylimidazole tetrafe Anion exchange of reaction products of ruborate, 2-undecylimidazole / tetraphenylborate, 2-heptadecylimidazole / tetraphenylborate, 1-ethyl-2-ethylimidazole / tetraphenylborate, aryl (halomethyl) ketone and imidazole And borate. Among these, it is preferable to use 2-ethyl-4-methylimidazole or the like because of excellent balance between storage stability and curability. These may be used alone or in combination of two or more.

  Specific examples of the tertiary amine compound include N, N-dimethylbenzylamine, 1,4-diazabicyclo [2.2.2] octane, N, N, N ′, N′-tetramethyl-m-. Xylenediamine, 4,4'-bis (dimethylamino) diphenylmethane, N, N, N ', N'-tetramethylisophoronediamine, N, N, N', N'-tetramethylmenthenediamine, 2,4,6 -Tris (N, N-dimethylaminomethyl) phenol, N-methylpiperidine, N, N-dimethyl-4-aminopyridine, N, N-dimethylaniline, N, N, N ', N'-tetramethylethylenediamine, Cyclic amine compounds such as N, N-dimethyl-2-phenylethylamine, quinuclidine, quinoxaline, N-methylmorpholine, N, N′-dimethylpipe Gin, triethylenediamine (also known as 1,4-diazabicyclo [2.2.2] octane) diazabicycloalkanes, such as, or diazabicycloalkenes like can be exemplified. Of these, diazabicycloalkenes are particularly preferred because of their high basicity. Specifically, 1,5-diazabicyclo [4.3.0] nonene-5, 1,8-diazabicyclo [5.4.0] undecene-7, 1,5,7-triazabicyclo [4.4. 0.0] Decaene-5 and the like. These may be used alone or in combination of two or more.

  It is preferable to set the usage-amount of the said basic hardening accelerator in the range of 1-10 weight part with respect to 100 weight part of phenol novolak resins. When the balance between curability and storage stability is more important, it is particularly preferably set to 2 to 5 parts by weight. That is, by setting to the above range, a product excellent in both curability and storage stability can be obtained.

  Moreover, it is preferable to mix | blend the usage-amount of a phenol novolak resin so that the hydroxyl equivalent in a phenol novolak resin may be 0.5-2.0 equivalent per 1 equivalent of epoxy groups in the said epoxy resin (C component). . More preferably, it is 0.8-1.2 equivalent.

  And in this invention, the said basic hardening accelerator produces a molten mixture by previously melt-mixing with the said phenol novolak resin. As described above, since the phenolic hydroxyl group that is an acidic group of the phenol novolak resin and the specific metal hydroxide compound (component A) are less likely to form a salt by being previously melt-mixed, the curability is reduced. Can be suppressed. From such a point, the basic curing accelerator to be used preferably has a pKa of 10 or more, preferably 11 or more. Therefore, specifically, 1,8-diazabicyclo [5.4.0] undecene-7 having a pKa of 12.5 and 1,5-diazabicyclo [4.3.0] nonene-5 having a pKa of 12.7. Etc. are preferably used.

  In the resin composition for semiconductor encapsulation of the present invention, in addition to the components A to D, a silane coupling agent, a pigment, a flame retardant, a flame retardant aid, a release agent, and the like are appropriately used as necessary. it can.

  The silane coupling agent has a functional group that reacts with at least one of a phenol novolak resin in an epoxy resin (C component) and a molten mixture (D component) and an alkoxysilane skeleton. For example, γ-mercaptopropyl Examples include trimethylsilane, γ-aminopropyltrimethylsilane, and γ-glycidoxypropyltrimethylsilane.

  Among these, in consideration of improving adhesion to a lead frame having a surface noble metal layer by plating or the like, it is preferable to use a silane coupling agent having a thiol group such as γ-mercaptopropyltrimethylsilane.

  And although the said silane coupling agent may be mixed with another compounding component, it is preferable to use it melt-mixed with the said basic hardening accelerator and a phenol novolak resin previously. In particular, when a silane coupling agent having a mercapto group is used, the mercapto group reacts with the epoxy resin. Therefore, if the mercapto group is protected with a basic curing accelerator, the storage stability of the resin composition is increased. In addition, the reaction with the epoxy resin is suppressed and good adhesion to the noble metal layer surface of the lead frame can be obtained. When a silane coupling agent having an epoxy group is used, the silane coupling agent is pre-reacted with a phenol novolac resin and has excellent resin wettability with an inorganic filler (component B). This is preferable. Furthermore, when an amino silane coupling agent is used, since the reactivity is high when the amino silane coupling agent and the epoxy resin (component C) are directly mixed, they are mixed and dispersed in advance in a phenol novolac resin. It is preferable that it can be uniformly dispersed in the resin composition.

  Examples of the pigment include carbon black having an electrostatic removal effect.

  Examples of the flame retardant include bromine-based flame retardant, nitrogen-based flame retardant, and phosphorus-based flame retardant. And it can use together with the above-mentioned specific metal hydroxide compound (A component).

  Examples of the flame retardant aid include antimony trioxide and the like, and exhibit an excellent flame retardant effect when used in combination with a bromine-based compound.

  The release agent is not particularly limited, and various conventionally known waxes such as oxidized polyethylene wax can be used.

  Furthermore, when such a resin composition is used as a sealing material, corrosion of the metal due to ionic impurities occurs. Therefore, an ion exchanger can be added to suppress the occurrence of metal corrosion due to ionic impurities. It is done. Examples of such ion exchangers include inorganic hydrotalcite compounds and bismuth compounds.

  The resin composition for semiconductor encapsulation of the present invention can be produced, for example, as follows. First, a molten mixture (component D) is prepared by previously adding a phenol novolak resin and a basic curing accelerator, and optionally adding a silane coupling agent thereto and melt-mixing them. As conditions for this melt mixing, for example, it is preferable to set to about 100 to 200 ° C. Next, the remaining components, a specific metal hydroxide compound (A component), an inorganic filler (B component), an epoxy resin (C component), and, if necessary, a flame retardant, a flame retardant aid, Other additives such as pigments and release agents are blended in a predetermined ratio. Next, these are melted and kneaded in a heated state using a kneader such as a mixing roll machine, cooled, and then pulverized by known means, and tableted as necessary in a tablet form. The target epoxy resin composition can be produced.

  The sealing of the semiconductor element using such an epoxy resin composition is not particularly limited, and can be performed by a known molding method such as ordinary transfer molding.

In the present invention, as described above, as a semiconductor device obtained by sealing a semiconductor element using a resin composition for semiconductor sealing, a semiconductor device having a size equal to or smaller than the following dimension (x) is used. It is intended.
(X) 2 mm long × 2 mm wide × 1 mm height.
That is, in a small semiconductor package using a conventional sealing material, the resin composition for semiconductor encapsulation of the present invention is used for resin sealing of a small semiconductor package having a size equal to or smaller than the dimension (x). It was difficult to remove the formed burrs, and a sealing resin portion excellent in mechanical strength, moldability, storage stability and flame retardancy was formed.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  Each component shown below was prepared.

〔Epoxy resin〕
o-Cresol novolac type epoxy resin (epoxy equivalent 198, softening point 55 ° C.)

[Phenolic resin]
Phenol formaldehyde novolak resin (hydroxyl equivalent 105, softening point 71 ° C)

[Inorganic filler a]
Spherical fused silica powder (average particle size 14μm, maximum particle size 64μm)
[Inorganic filler b]
Crushed fused silica powder (average particle size 6μm, maximum particle size 32μm)
[Inorganic filler c]
Spherical fused silica powder (average particle size 1 μm, maximum particle size 6 μm)

[Aluminum hydroxide a]
The average particle diameter of 12 [mu] m, a specific surface area of 1.3 m ² / g
[Aluminum hydroxide b]
Average particle size 3μm, specific surface area 1.4m ² / g
[Aluminum hydroxide c]
Average particle size 20 μm, specific surface area 0.8 m ² / g
[Magnesium hydroxide]
Average particle size 1 μm, specific surface area 4.0 m ² / g

[Pigment]
Carbon black (average particle size 25 nm, a nitrogen adsorption specific surface area 120m ² / g, DBP adsorption of 120cm ³ / 100g, pH8)

[Curing accelerator a]
1,8-diazabicyclo [5.4.0] undecene-7 (DBU) (pKa: 12.5)
[Curing accelerator b]
1,5-diazabicyclo [4.3.0] nonene-5 (DBN) (pKa: 12.7)
[Curing accelerator c]
Triphenylphosphine (pKa: 3)

〔Silane coupling agent〕
γ-mercaptopropyltrimethylsilane

[Examples 1-7, Comparative Examples 1-5]
Each component shown above was mix | blended in the ratio shown in Table 1-Table 2 of the postscript, and it melt-kneaded for 5 minutes over the roll kneader heated to 80-120 degreeC. Next, after cooling the melt, the solid was pulverized into a powder. Next, the obtained powder was filled into a cylindrical mold and pressurized from both ends of the cylinder to prepare a columnar tablet-shaped epoxy resin composition. In Examples 1 and 4, a phenol resin and a curing accelerator were previously melt-mixed (170 ° C.) at a ratio shown in the same table to prepare a premix, and then the premix and the other remaining components were mixed. Blended. In Examples 2, 3, 5, 6, and 7 and Comparative Examples 1 to 2 and 4 to 5, the phenol resin, the curing accelerator, and the silane coupling agent were previously melt-mixed at a ratio shown in the same table (170 C.) to prepare a premix, and then blend this premix with the other remaining ingredients. On the other hand, Comparative Example 3 was not previously melt mixed.

  Using the tablet-like epoxy resin compositions of Examples and Comparative Examples thus obtained, using a low-pressure transfer molding machine, the molding temperature was 175 ° C., the injection pressure was 7 MPa, and the curing time was 120 seconds. A molded product (cured product) of × 2 mm × thickness 0.7 mm was produced. And using this, it measured and evaluated in accordance with the following method about moldability, a burr | flash removal property, preservability, and a flame retardance. The results are also shown in Tables 1 and 2 below.

[Formability]
There are 6 rows of 10 connections with holes (0.15mm height) communicating with the next 2mm x 2mm x 0.7mm cavity on the opposite side of the gate of the 2mm x 2mm x 0.7mm cavity gate At the same time, evaluation was performed using a mold capable of molding 60 pieces. Then, it was confirmed and evaluated at what number of connected cavities unfilled. As a result, the case where there was no unfilled up to the fifth piece was indicated as ◯, and the others were indicated as ×.

[Burr removal]
The burr part of the molded product was folded and cracked into a molded product having a size of 2 mm × 2 mm × 0.7 mm, and whether or not a recess of 0.1 mm or more was generated was evaluated. As a result, those having no cracks or recesses were indicated as ◯, and others were indicated as ×.

[Preservation]
Using a tablet-shaped epoxy resin composition stored at room temperature (25 ° C.) for 10 days, a molded product was produced under the above conditions, and moldability was confirmed and evaluated. As a result, the unfilled up to the fifth connected cavity was indicated as ◯, the unfilled up to the fourth connected cavity as Δ, and the others as x.

〔Flame retardance〕
Using a low-pressure transfer molding machine, a 3.2 mm-thick test piece (size: 127 mm × 12.7 mm × 3.2 mm) was molded under conditions of a molding temperature of 175 ° C., an injection pressure of 7 MPa, and a curing time of 120 seconds. . And it took out from the metal mold | die and processed for 5 hours at the postcure 175 degreeC. Using this, the total combustion time and the longest combustion time were determined according to the UL-94 vertical method, and whether or not the V-0 standard was satisfied was evaluated. As a result, those satisfying the V-0 standard were indicated as ◯, and those not satisfying as X.

  From the above results, the example product obtained by preparing a premix and blending this and the remaining components gave good results regarding moldability, deburring property, storage stability and flame retardancy. In particular, the products of Examples 2, 3, and 5 using a premix of a phenol resin, aluminum hydroxide, and a silane coupling agent gave excellent results in terms of storage stability.

  On the other hand, the comparative example 1 product using aluminum hydroxide outside the specific range and the comparative example 2 product using magnesium hydroxide have at least one of moldability, deburring property, storage stability and flame retardancy. One characteristic was inferior. Moreover, the comparative example 3 product which does not produce a preliminary mixture and mix | blends each component simultaneously was inferior to a burr | flash removal property and preservability. And the comparative example 4 goods using hardening accelerators other than a basic hardening accelerator are inferior to a moldability and a burr | flash removal property, and the comparative example 5 goods which did not use aluminum hydroxide are a burr | flash removal property and It was inferior in flame retardancy.

  Next, an 8-pin small semiconductor device (size: length 2 mm × width 2 mm × height 0.7 mm) was produced using the tablet-shaped epoxy resin composition of the above-described example by a low-pressure transfer molding machine. The molding conditions were a molding temperature of 175 ° C., an injection pressure of 7 MPa, a curing time of 120 seconds, and post-curing at 175 ° C. for 5 hours. The obtained small semiconductor device had good moldability and high reliability with no appearance damage even when burrs were removed.

Claims (8)

A semiconductor sealing resin composition used as a sealing material for a semiconductor device having a size of the following dimension (x) or less, wherein the following (A) to (D) components are used: Resin composition for stopping.
(X) 2 mm long × 2 mm wide × 1 mm height.
(A) an average particle diameter of 1 to 20 [mu] m, and a specific surface area of 1 to 2 m ² / g hydroxide metal compound.
(B) An inorganic filler other than the component (A).
(C) Epoxy resin.
(D) A molten mixture obtained by melting and mixing a phenol novolac resin and a basic curing accelerator.   The resin composition for semiconductor encapsulation according to claim 1, wherein the metal hydroxide compound as the component (A) is aluminum hydroxide.   The resin composition for semiconductor encapsulation according to claim 1 or 2, wherein the basic curing accelerator used for the component (D) is a diazabicycloalkene compound.   The resin composition for semiconductor encapsulation according to any one of claims 1 to 3, further comprising a mercapto group-containing silane coupling agent in addition to the components (A) to (D).   The said (D) component is a molten mixture formed by mix | blending the said mercapto group containing silane coupling agent with a phenol novolak resin and a basic hardening accelerator, and melt-mixing these compounding components beforehand. Semiconductor sealing resin composition. A method for producing a resin composition for encapsulating a semiconductor used as an encapsulating material for a semiconductor device having a size of the following dimension (x) or less, wherein a phenol novolac resin and a basic curing accelerator are melt-mixed in advance. After manufacturing a molten mixture by this, the said molten mixture and the following (A)-(C) component are melt-kneaded, The manufacturing method of the resin composition for semiconductor sealing characterized by the above-mentioned.
(X) 2 mm long × 2 mm wide × 1 mm height.
(A) A metal hydroxide compound having an average particle diameter of 1 to 20 μm and a specific surface area of 1 to ² m ² / g.
(B) An inorganic filler other than the component (A).
(C) Epoxy resin.   The manufacturing method of the resin composition for semiconductor sealing of Claim 6 which produces a molten mixture by mix | blending and melt-mixing a mercapto group containing silane coupling agent with a phenol novolak resin and a basic hardening accelerator. The semiconductor device of the magnitude | size below the following dimension (x) formed by sealing a semiconductor element using the resin composition for semiconductor sealing as described in any one of Claims 1-5.
(X) 2 mm long × 2 mm wide × 1 mm height.