TWI652284B - Mold underfill material for compression molding, semiconductor package, structure and method for manufacturing semiconductor package - Google Patents

Abstract

The present invention is a mold underfill material for compression molding, which seals a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element, and contains an epoxy resin (A) and a hardener. (B) and the inorganic filler (C), and the underfill material for the compression molding mold is a powder or granule, and when the measurement is performed at a mold temperature of 175 ° C using a curelastometer, the measurement is started from the start to the measurement. The time T(5) until the maximum torque is 5% is 25 seconds or more and 100 seconds or less.

Description

Die underfill material for compression molding, semiconductor package, structure, and method of manufacturing semiconductor package

The present invention relates to a mold underfill material for compression molding, a semiconductor package, a structure, and a method of manufacturing a semiconductor package.

In a semiconductor package in which a semiconductor element is mounted on a substrate, there is a case where a mold underfill material is used to fill a gap between the substrate and the semiconductor element and to seal the semiconductor element. As a technique related to the mold underfill material, for example, those described in Patent Document 1 can be cited.

Patent Document 1 is a technique for an epoxy resin composition for a mold underfill material. Specifically, a non-liquid epoxy resin composition containing an epoxy resin, a curing agent, an inorganic filler, and a curing accelerator is described.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-132268

When the filling of the gap between the substrate and the semiconductor element and the sealing of the semiconductor element are performed once using the underfill material of the mold, the filling property of the gap may not be sufficiently obtained. Therefore, a mold underfill material excellent in filling property is required.

According to the present invention, there is provided a mold underfill material for compression molding which seals a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element, and contains: an epoxy resin (A) The hardener (B) and the inorganic filler (C), and the underfill material for the compression molding is a powder or granule, and when measured at a mold temperature of 175 ° C using a curelastometer, The time T(5) from the start of measurement until reaching 5% of the maximum torque is 25 seconds or more and 100 seconds or less.

According to the present invention, there is provided a semiconductor package obtained by sealing a semiconductor element disposed on a substrate by using the underfill material for compression molding, and filling a gap between the substrate and the semiconductor element.

According to the present invention, there is provided a structure obtained by: The plurality of semiconductor elements disposed on the substrate are sealed by the underfill material for compression molding, and a gap between the substrate and each of the semiconductor elements is filled.

According to the present invention, there is provided a method of fabricating a semiconductor package comprising: disposing a semiconductor element on a substrate by interposing a bump; and using the compression molding method to form the semiconductor element by the under molding material for the compression molding die Sealing and filling a gap between the substrate and the semiconductor element.

According to the present invention, a mold underfill material excellent in filling property can be realized.

10‧‧‧Substrate

20‧‧‧Semiconductor components

22‧‧‧Bumps

24‧‧‧ gap

30‧‧‧ Sealing material

100‧‧‧Semiconductor package

102‧‧‧Buildings

The above and other objects, features and advantages of the present invention will become more apparent from

Fig. 1 is a cross-sectional view showing the semiconductor package of the embodiment.

Fig. 2 is a cross-sectional view showing the structure of the embodiment.

Hereinafter, an embodiment will be described using a drawing. In the drawings, the same components are denoted by the same reference numerals, and the description is omitted as appropriate.

(First embodiment)

The mold underfill material of the present embodiment seals the semiconductor element disposed on the substrate and fills the gap between the substrate and the semiconductor element. Compression forming mold bottom filling The filling material contains an epoxy resin (A), a hardener (B), and an inorganic filler (C). Further, the underfill material for the mold for compression molding is a powder or granule. Further, the under molding material for the compression molding mold is a time period in which the time T (5) is 25 seconds or more from the start of measurement to 5% of the maximum torque when the mold temperature is 175 ° C using a vulcanizer. And less than 100 seconds.

The sealing of the semiconductor element using the underfill material of the mold and the filling of the gap under the semiconductor element can be considered, for example, by a transfer molding method. However, in this case, there is a case where it is difficult to obtain a stable and excellent filling property with respect to the above gap. This situation is particularly pronounced in the case of large area MAP formation. In view of such circumstances, the inventors of the present invention have studied the sealing formation of a mold underfill material by a compression molding method. However, in such a case, a more excellent filling property with respect to the gap between the substrate and the semiconductor element is also required.

The present inventors have newly recognized that by controlling the hardening characteristics measured by the vulcanizer for the underfill material of the mold, it is possible to improve the sealing of the semiconductor element and the filling of the gap below the semiconductor element by the compression molding method. Filling. In the present embodiment, based on such knowledge, it is possible to provide a time T(5) of 25 seconds or more from the start of measurement to 5% of the maximum torque when the mold temperature is 175 ° C using a vulcanizer. A mold underfill material for compression molding of 100 seconds or less. Thereby, a mold underfill material excellent in filling property can be realized.

Hereinafter, the mold base material for compression molding, the semiconductor package 100, and the structure 102 of the present embodiment will be described in detail.

First, the underfill material for the compression molding mold will be described.

The mold underfill material for compression molding seals the semiconductor element disposed on the substrate and fills the gap between the substrate and the semiconductor element. Semiconductor component sealing and substrate The filling of the gap with the semiconductor element is performed once using a compression molding method. Thereby, the molding of the underfill material of the mold excellent in filling property or ash uniformity can be performed. Such an effect is particularly apparent, for example, in the case of sealing formation of a large area such as MAP molding.

The substrate is, for example, a wiring substrate such as a plug-in substrate. Further, the semiconductor element is, for example, flip chip mounted on the substrate. A semiconductor package such as a BGA (Ball Grid Array) or a CSP (Chip Size Package) is formed by using a sealing and filling of a mold under molding material for compression molding, and is also related to the use of such a package in recent years. A formed body formed by molding a formed MAP (Mold Array Package).

The underfill material for the compression molding die is a powder or granule. Therefore, the molding of the underfill material of the mold excellent in filling property or ash uniformity can be performed by the compression molding method. In addition, the mold underfill material for compression molding is a case where the powder system refers to any of powder or granules. The mold underfill material for compression molding of the present embodiment can be formed, for example, in the form of pellets.

Further, by using the compression molding of the under molding material for compression molding of the present embodiment which is a powder or granule, it is possible to achieve more excellent transfer molding than using a mold underfill material which is not a granular material and a flat mold. Fillability and ash uniformity.

The mold underfill material for compression molding of the present embodiment is a particle size distribution measured by sieving using a JIS standard sieve, and the ratio of the fine powder having a particle diameter of less than 106 μm to the entire underfill material for the compression molding mold is higher. It is preferably 5% by mass or less, more preferably 3% by mass or less. By setting the ratio of the fine powder having a particle diameter of less than 106 μm to the upper limit or less, the material of the powder or granules is not melted and becomes uniformly melted when dispersed on the mold, and partial gelation can be suppressed. Or hardening unevenly. Therefore, it is possible to improve the ash uniformity or formability during compression molding. high.

Further, the under molding material for the compression molding of the present embodiment is a particle size distribution measured by sieving using a JIS standard sieve, and the coarse particles having a particle diameter of 2 mm or more are integrated with the underfill material for the compression molding die. The ratio is preferably 3% by mass or less, more preferably 2% by mass or less. By setting the ratio of the coarse particles having a particle diameter of 2 mm or more to the upper limit or less, it is possible to reduce the unevenness in dispersion during compression molding and to improve the uniformity of the thickness of the cured resin. Further, when the material is dispersed on the mold, the material of the powder or granule does not become a bulk and is uniformly melted, and partial gelation or hardening unevenness is suppressed, and ash uniformity or moldability at the time of compression molding can be improved.

As a method of measuring the particle size distribution of the underfill material for the compression molding die, the following method is exemplified: the JIS standard of the meshes of 2.00 mm, 1.00 mm, and 106 μm provided by the ro-tap type sieve machine is used. The sieve was shaken (the number of hammers: 120 times/min) for 20 minutes, and 40 g of the sample was sieved and classified to obtain particles remaining on the sieve of 2.00 mm and 1.00 mm with respect to the classification. The ratio (% by mass) of the total sample mass, and the ratio (% by mass) of the fine powder passing through the 106 μm sieve to the total sample mass before classification.

Furthermore, in the case of using this method, there is a possibility that particles having a relatively high aspect ratio pass through each sieve. Therefore, when the particle size distribution is measured by the above method, for example, the mass % of each component classified according to the above-described fixing conditions can be defined as particles having a particle diameter corresponding to each component with respect to the bottom of the compression molding die. The ratio of the overall material.

In the present embodiment, the underfill material for the compression molding mold is a time T (5) from the start of measurement to 5% of the maximum torque when the mold temperature is 175 ° C using a vulcanizer. It is 25 seconds or more and 100 seconds or less. Here, for example, the torque at the time of 300 seconds from the start of the measurement can be defined as the maximum torque.

By setting the time T (5) to 25 seconds or longer, it is possible to improve the filling property of the gap between the substrate and the semiconductor element at the time of compression molding. On the other hand, by setting the time T (5) to 100 seconds or less, sufficient hardenability can be achieved at the time of compression molding. As described above, by controlling the hardening characteristics measured by the vulcanizer, it is possible to realize a mold underfill material which is excellent in filling property or hardenability at the time of compression molding. Further, from the viewpoint of improving the filling property and the hardenability, the time T(5) is more preferably 30 seconds or more and 90 seconds or less, and more preferably 45 seconds or more in consideration of more stability of filling property or ash uniformity. And less than 80 seconds.

In addition, the time T (5) can be controlled, for example, by appropriately adjusting the type or content of each component contained in the underfill material for the compression molding die, the particle size distribution of the underfill material for the compression molding die, and the like. In the present embodiment, for example, the type or content of the curing agent (B) or the inorganic filler (C) is adjusted, and when the curing accelerator (D) or the coupling agent (E) is contained, the contents are adjusted. Type or content.

The mold underfill material for compression molding of the present embodiment has a viscosity η of 175 ° C measured by a flow tester of, for example, 3.5 Pa ‧ sec. or more and 15 Pa ‧ sec or less. By setting the viscosity η to 3.5 Pa ‧ sec or more, it is possible to realize a mold base material for compression molding which is excellent in moldability. Moreover, by setting the viscosity η to 15 Pa ‧ seconds or less, it is possible to more effectively improve the filling property of the gap between the substrate and the semiconductor element during compression molding. Further, from the viewpoint of improving moldability and filling properties, the viscosity η is preferably 3.5 Pa ‧ or more and 10 Pa ‧ seconds or less, and more preferably 4.0 Pa ‧ sec. or more and 10 Pa ‧ sec or less.

In addition, the viscosity η can be controlled, for example, by appropriately adjusting the type or content of each component contained in the underfill material for the compression molding die, the particle size distribution of the underfill material for the compression molding die, and the like.

In the present embodiment, the apparent viscosity of the melt-molding mold underfill material can be set to a viscosity η, which is, for example, a high-pressure flow tester at a temperature of 175 ° C and a load of 40 kgf (piston area). The measurement was carried out under the test conditions of 1 cm ² ), a die hole diameter of 0.50 mm, and a die length of 1.00 mm. In this case, the viscosity η can be calculated, for example, by the following calculation formula. In the calculation formula, Q is the flow rate of the underfill material of the mold flowing per unit time.

η = (4πDP / 128LQ) × 10 ^-3 (Pa ‧ seconds)

η: apparent viscosity

D: die hole diameter (mm)

P: test pressure (Pa)

L: die length (mm)

Q: flow rate (cm ³ / sec)

In the present embodiment, by adjusting the time T(5)/viscosity η, the balance between the filling property, the moldability, the fluidity, and the hardenability of the under molding material for the compression molding die can be improved. On the viewpoint of improving the balance of these, the time T (5) / the viscosity η is preferably e.g. 2Pa ^-1 or more and 30Pa ^-1 or less, more preferably 4Pa ^-1 or more and 25Pa ^-1 or less, particularly preferably 5 Pa ^-1 or more and 20 Pa ^-1 or less. By setting the time T(5)/viscosity η to be equal to or higher than the above lower limit value, the fluidity and the filling property can be improved with good balance. In addition, when the time T(5)/viscosity η is equal to or less than the above upper limit value, it is possible to reliably suppress the deterioration of the curability or the formability and to improve the filling property. In the present invention, in particular, in order to make the filling property and the uniform formability of the minute space between the semiconductor element and the substrate of the structure formed of a large area such as MAP coexist with the unprecedented characteristics, time T(5)/ The value of viscosity η becomes an important concept.

The mold underfill material for compression molding contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C). Thereby, the molding of the underfill material for the compression molding die can be performed by the compression molding method.

((A) epoxy resin)

As the epoxy resin (A), all monomers, oligomers, and polymers having two or more epoxy groups in one molecule can be used, and the molecular weight or molecular structure thereof is not particularly limited.

In the present embodiment, examples of the epoxy resin (A) include a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a tetramethyl bisphenol F type epoxy. Bisphenol type epoxy resin such as resin; bismuth type epoxy resin; phenol novolak type epoxy resin, phenol novolak type epoxy resin and other novolak type epoxy resin; trisphenol methane type epoxy resin, alkyl group Modified polyfunctional epoxy resin such as trisphenol methane epoxy resin; phenol aralkyl epoxy resin having a phenyl group skeleton; aralkyl group such as phenol aralkyl epoxy resin having a benzene skeleton; Epoxy resin; dihydroxynaphthalene type epoxy resin; a naphthol type epoxy resin such as an epoxy resin obtained by subjecting a dihydroxy naphthalene dimer to a glycidyl ether; a triglycidyl isocyanurate , iso-cyanuric acid monoallyl diglycidyl ester, etc. The epoxy resin of the core; the bridged cyclic hydrocarbon compound modified phenol type epoxy resin such as a dicyclopentadiene-modified phenol type epoxy resin, which may be used alone or in combination of two or more. Among these, bisphenol type epoxy resins such as biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and tetramethyl bisphenol F type epoxy resin, and bismuth type The epoxy resin is preferably one having crystallinity.

As the epoxy resin (A), it is preferable to use an epoxy resin represented by the following formula (1), an epoxy resin represented by the following formula (2), and an epoxy compound represented by the following formula (3). At least one of the group consisting of resins.

(In the formula (1), Ar ¹ represents a phenyl or anthracene group, and in the case where Ar ¹ is a naphthyl group, the epoxypropyl ether group may be bonded to any of the α position and the β position. ² represents any one of a phenyl group, a biphenyl group, or a naphthyl group. R _a and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. g is an integer of 0 to 5, and h is 0. An integer of 8. n ³ represents the degree of polymerization, and the average value is 1 to 3)

(In the formula (2), a plurality of R _c each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4)

(In the formula (3), a plurality of R _d and R _e each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n ⁶ represents a degree of polymerization, and the average value thereof is 0 to 4)

In the present embodiment, the epoxy tree in the underfill material of the compression molding die The content of the fat (A) is preferably 3% by mass or more, more preferably 4% by mass or more, and particularly preferably 6% by mass or more based on the entire underfill material for compression molding. When the content of the epoxy resin (A) is at least the above lower limit value, sufficient fluidity can be achieved at the time of compression molding, and the filling property or moldability can be improved.

On the other hand, the content of the epoxy resin (A) in the underfill material for compression molding is preferably 30% by mass or less, and more preferably 20% by mass or less, based on the entire underfill material for compression molding. By setting the content of the epoxy resin (A) to be equal to or less than the above upper limit value, the semiconductor package formed using the underfill material for compression molding can improve moisture resistance reliability and solder reflow resistance.

((B) hardener)

The curing agent (B) contained in the resin composition for sealing can be roughly classified into three types of an addition polymerization type hardener, a catalyst type hardener, and a condensation type hardener.

Examples of the addition polymerization type curing agent used for the curing agent (B) include fats such as diethyltriamine (DETA), triethylidenetetramine (TETA), and m-xylylenediamine (MXDA). A polyamine; an aromatic polyamine such as diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA) or diaminodiphenyl hydrazine (DDS), and further includes dicyandiamide (DICY), organic a polyamine compound such as diterpene acid; an alicyclic acid anhydride such as hexahydrophthalic anhydride (HHPA) or tetrahydrophthalic anhydride (MTHPA), trimellitic anhydride (TMA), and pyromelli-4 An acid anhydride such as formic acid dianhydride (PMDA) or benzophenone tetracarboxylic acid dianhydride (BTDA); a phenol resin-based curing agent such as a novolac type phenol resin or a polyvinyl phenol; a polythioether or a thioester; a polythiol compound such as a sulfide; an isocyanate compound such as an isocyanate prepolymer or a blocked isocyanate; an organic acid such as a carboxylic acid-containing polyester resin.

Examples of the catalyst-type curing agent used for the curing agent (B) include dimethylbenzylamine (BDMA) and 2,4,6-tris-dimethylaminomethylphenol (DMP-30). A tertiary amine compound; an imidazole compound such as 2-methylimidazole or 2-ethyl-4-methylimidazole (EMI24); a Lewis acid such as a BF ₃ complex or the like.

Examples of the condensing type hardener used for the hardener (B) include a resol type phenol resin; a urea resin such as a hydroxymethyl group-containing urea resin; and a melamine resin containing a methylol group. Melamine resin and the like.

Among these, a phenol resin-based curing agent is preferred from the viewpoint of improving the balance between flame resistance, moisture resistance, electrical properties, curability, and storage stability. As the phenol resin-based curing agent, all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule can be used, and the molecular weight and molecular structure thereof are not particularly limited.

Examples of the phenol resin-based curing agent used for the curing agent (B) include a phenol novolak resin, a cresol novolak resin, and a novolak type phenol resin such as a bisphenol novolak; polyvinylphenol; triphenol methane; Polyfunctional phenolic resin such as phenolic resin; modified phenolic resin such as terpene modified phenol resin or dicyclopentadiene modified phenol resin; phenol aralkyl resin having phenylene skeleton and/or extended benzene skeleton An aralkyl type phenol resin such as a naphthol aralkyl resin having a stretching phenyl group and/or a stretching benzene skeleton; a bisphenol compound such as bisphenol A or bisphenol F; and the like may be used singly or in combination Two or more. Among these, from the viewpoint of improving the hardenability of the underfill material for the mold for compression molding, it is more preferred to use a polyfunctional phenol resin or an aralkyl type phenol resin.

In the present embodiment, the content of the curing agent (B) in the under molding material for the compression molding die is preferably 1% by mass or more, and more preferably 2% by mass or more, more preferably 2% by mass or more, based on the entire underfill material for compression molding. Good is 3 mass% or more. By containing the hardener (B) When the amount is at least the above lower limit value, excellent fluidity can be achieved at the time of compression molding, and the filling property or moldability can be improved.

On the other hand, the content of the hardener (B) in the underfill material for compression molding is preferably 25% by mass or less, more preferably 15% by mass or less, and more preferably 15% by mass or less, based on the entire underfill material for compression molding. 10% by mass or less. By setting the content of the curing agent (B) to be equal to or less than the above upper limit value, it is possible to improve the moisture resistance reliability or the reflow resistance of the semiconductor package formed using the under molding material for the compression molding die.

((C) inorganic filler)

The constituent material of the inorganic filler (C) is not particularly limited, and examples thereof include silica, alumina, tantalum nitride, and aluminum nitride such as molten cerium oxide and crystalline cerium oxide. Any one or more of these may be used. Among these, in view of excellent versatility, it is more preferable to use cerium oxide, and it is more preferable to use molten cerium oxide. Further, the inorganic filler (C) is preferably spherical, and more preferably spherical cerium oxide. Thereby, the fluidity of the underfill material for the compression molding mold at the time of compression molding can be effectively improved.

The inorganic filler (C) is, for example, observed from the largest particle diameter side of the volume-based particle size distribution, and has a particle diameter R _max of 5% of the cumulative frequency of 8 μm or more and 35 μm or less. Thereby, the dispersibility of the inorganic filler (C) can be improved, and the ash uniformity can be effectively improved. Moreover, the fluidity of the underfill material of the mold for compression molding can also be improved. The particle diameter R _max is more preferably 10 μm or more and 25 μm or less, and particularly preferably 11 μm or more and 23 μm or less from the viewpoint of effectively improving the balance of ash uniformity and fluidity.

Further, the inorganic filler (C) has a particle diameter corresponding to the largest peak of the volume-based particle size distribution as a mode diameter R, and a mode diameter R is preferably 1 μm or more. Further, it is 24 μm or less, more preferably 3 μm or more and 24 μm or less, and particularly preferably 4.5 μm or more and 24 μm or less. Thereby, the filling property of the slit between the substrate and the semiconductor element and the uniform formability at the time of MAP molding of a large area can be more effectively improved at the time of compression molding.

The R/R _{max of the} inorganic filler (C) is preferably 0.4 or more, more preferably more than 0.50, from the viewpoint of more effectively improving the balance of filling property, fluidity, and ash uniformity at the time of compression molding. Good is 0.52 or more. Further, from the viewpoint of improving the filling property at the time of compression molding, the inorganic filler (C) preferably satisfies the relationship of R < R _max . In this case, R/R _max becomes less than 1.0.

In the volume-based particle size distribution of the inorganic filler (C) as a whole, the frequency of the particles having the mode diameter R is preferably 3.5% or more and 15% or less, more preferably 4% or more and 10% or less, and particularly preferably 4.5. More than % and less than 9%. Thereby, the ratio of the particles having the mode diameter R or the particle diameter close to the mode diameter R can be made high. Therefore, the balance of fluidity and filling property can be more effectively improved for the underfill material for the mold for compression molding.

Further, in the volume-based particle size distribution of the entire inorganic filler (C), the frequency of particles having a particle diameter of 0.8 × R or more and 1.2 × R or less is preferably 10% or more and 60% or less, more preferably 12%. The above is 50% or less, and particularly preferably 15% or more and 45% or less. Thereby, the ratio of the particles having the mode diameter R or the particle diameter close to the mode diameter R can be surely made high. Therefore, the balance of fluidity and filling property can be more effectively improved for the underfill material for the mold for compression molding.

Further, in the volume-based particle size distribution of the entire inorganic filler (C), the frequency of the particles having a particle diameter of 0.5 × R or less is preferably 5% or more and 50% or less. By setting the frequency of the particles having a relatively small particle diameter with respect to the mode diameter R to the above range, it is possible to achieve more excellent fluidity. Forming mold underfill material.

Further, the particle size distribution of the inorganic filler (C) can be adjusted, for example, by classifying the raw material particles using a sieve or a cyclone (air classification). Further, the measurement of the particle size distribution of the inorganic filler (C) such as the particle diameter R _max or the mode diameter R can be carried out, for example, by using a laser diffraction scattering type particle size distribution analyzer SALD-7000 manufactured by Shimadzu Corporation.

In the present embodiment, the content of the inorganic filler (C) in the under molding material for the compression molding die is preferably 50% by mass or more, and more preferably 60% by mass or more based on the entire underfill material for compression molding. When the content of the inorganic filler (C) is at least the above lower limit value, the low moisture absorption property and the low thermal expansion property can be improved, and the moisture resistance reliability and the reflow resistance of the semiconductor package can be more effectively improved.

On the other hand, the content of the inorganic filler (C) in the underfill material for compression molding is preferably 93% by mass or less, and more preferably 91% by mass or less based on the entire underfill material for compression molding. By setting the content of the inorganic filler (C) to be equal to or less than the above upper limit value, fluidity or filling property at the time of compression molding of the under molding material for a compression molding die can be more effectively improved.

((D) hardening accelerator)

The mold underfill material for compression molding may further contain, for example, a hardening accelerator (D). The curing accelerator (D) may be a crosslinking reaction for promoting the epoxy group of the epoxy resin (A) and the curing agent (B) (for example, a phenolic hydroxyl group of the phenol resin-based curing agent), and for example, it may be used. Usually used for sealing epoxy resin compositions. Examples of the curing accelerator (D) include an organic phosphine, a tetra-substituted fluorene compound, a phosphate betaine compound, an adduct of a phosphine compound and a hydrazine compound, and an phosphorus-containing atom such as an adduct of a hydrazine compound and a decane compound. Compound; exemplified 1,8-diazabicyclo (5,4,0) anthracene or a tertiary amine such as undecene-7, dimethylbenzylamine or 2-methylimidazole; and a compound containing a nitrogen atom such as a quaternary salt of the above hydrazine or an amine; These may be used alone or in combination of two or more. Among these, a compound containing a phosphorus atom is more preferably used from the viewpoint of improving hardenability. Further, from the viewpoint of improving the balance between fluidity and hardenability, it is more preferred to use a tetra-substituted fluorene compound, a phosphate betaine compound, an addition product of a phosphine compound and a hydrazine compound, and an addition of a hydrazine compound and a decane compound. A latent hardening accelerator such as a substance. Further, from the viewpoint of improving the filling property at the time of compression molding, it is particularly preferred to use an adduct of a phosphine compound and a hydrazine compound or an adduct of a hydrazine compound and a decane compound. Further, from the viewpoint of production cost, an organic phosphine or a compound containing a nitrogen atom can also be preferably used.

Examples of the organophosphine used as the curing accelerator (D) include a primary phosphine such as ethylphosphine and phenylphosphine; a secondary phosphine such as dimethylphosphine or diphenylphosphine; and trimethylphosphine and triethylphosphine. A tertiary phosphine such as phosphine, tributylphosphine or triphenylphosphine.

The tetrasubstituted fluorene compound used as the curing accelerator (D) is, for example, a compound represented by the following formula (4).

(In the formula (4), P represents a phosphorus atom, and R1, R2, R3, and R4 each independently represent an aromatic group or an alkyl group, and A represents at least one selected from the group consisting of a hydroxyl group, a carboxyl group, and a thiol group in the aromatic ring. An anion of an aromatic organic acid of any one of the functional groups, and AH represents an aromatic organic acid having at least one of a functional group selected from a hydroxyl group, a carboxyl group and a thiol group in the aromatic ring, x and y is the number from 1 to 3, z is the number from 0 to 3, and x = y)

The compound represented by the formula (4) is obtained, for example, by the following means, but is not limited thereto. First, a tetrasubstituted phosphonium halide, an aromatic organic acid, and a base are mixed into an organic solvent and uniformly mixed to produce an aromatic organic acid anion in the solution system. Then, when water is added, the compound represented by the formula (4) can be precipitated. In the compound represented by the formula (4), R1, R2, R3 and R4 which are bonded to a phosphorus atom are preferably a phenyl group from the viewpoint of excellent balance between the yield at the time of synthesis and the effect of curing the hardening. And AH is a compound having a hydroxyl group on the aromatic ring, that is, a phenol compound, and A is an anion of the phenol compound. Further, the phenolic compound conceptually includes a monocyclic phenol, cresol, catechol, resorcin or condensed polycyclic naphthol, dihydroxynaphthalene, and a plurality of aromatic rings (polycyclic) Among them, bisphenol A, bisphenol F, bisphenol S, biphenol, phenylphenol, phenol novolac, and the like, among these, a phenol compound having two hydroxyl groups is preferably used.

The phosphate betained compound used as the curing accelerator (D) is, for example, a compound represented by the following formula (5).

(In the formula (5), X1 represents an alkyl group having 1 to 3 carbon atoms, Y1 represents a hydroxyl group, a is an integer of 0 to 5, and b is an integer of 0 to 4)

The compound represented by the formula (5) is not particularly limited and can be, for example, as follows The step is carried out by contacting a triaromatic substituted phosphine as a tertiary phosphine with a diazonium salt, and substituting the triaromatic substituted phosphine with a diazonium group of the diazonium salt.

The compound represented by the following formula (6), etc., as an adduct of the phosphine compound and the hydrazine compound used as the hardening accelerator (D), for example.

(In the formula (6), P represents a phosphorus atom, and R5, R6, and R7 independently of each other represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R8, R9, and R10 are independently of each other. A hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R8 and R9 may be bonded to each other to form a ring)

As the phosphine compound for the adduct of the phosphine compound and the ruthenium compound, for example, triphenylphosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, trinaphthylphosphine, and the like are preferable. The aromatic ring such as (benzyl)phosphine is unsubstituted or a substituent such as an alkyl group or an alkoxy group is present on the aromatic ring. Examples of the substituent such as an alkyl group or an alkoxy group include those having a carbon number of 1 to 6. . From the standpoint of easy availability, triphenylphosphine is preferred.

Further, examples of the ruthenium compound used for the adduct of the phosphine compound and the ruthenium compound include o-benzoquinone, p-benzoquinone, and anthracene. Among them, in terms of storage stability, it is preferably Phenylhydrazine.

The adduct of the phosphine compound and the hydrazine compound is not particularly limited, and it can be obtained, for example, by contacting and mixing these solvents in a solvent in which both the organic trisphosphine and the benzoquinone are dissolved. Make The solvent is preferably a ketone such as acetone or methyl ethyl ketone and has a low solubility in an additive.

In the compound represented by the formula (6), in terms of reducing the thermal modulus of elasticity of the underfill material for the compression molding mold after hardening, R5, R6, and R7 bonded to the phosphorus atom are preferred. A compound which is a phenyl group and wherein R8, R9 and R10 are a hydrogen atom, that is, a compound obtained by adding 1,4-benzoquinone to triphenylphosphine.

Examples of the adduct of the oxime compound and the decane compound used as the curing accelerator (D) include a compound represented by the following formula (7).

(In the formula (7), P represents a phosphorus atom, and Si represents a ruthenium atom. R11, R12, R13, and R14 independently of each other represent an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group, and X2 is a group Y2 And an organic group bonded to Y3. X3 is an organic group bonded to the group Y4 and Y5. Y2 and Y3 are groups in which a proton-donating group releases a proton, and a group Y2 and Y3 in the same molecule are bonded to a ruthenium atom. A chelate structure is formed, and Y4 and Y5 represent a proton-donating group which releases a proton, and the groups Y4 and Y5 in the same molecule are bonded to a deuterium atom to form a chelate structure. X2 and X3 may be identical to each other. Alternatively, Y2, Y3, Y4, and Y5 may be the same or different from each other. Z1 is an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group)

In the general formula (7), examples of R11, R12, R13 and R14 include a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group, a naphthyl group, a hydroxynaphthyl group, a benzyl group and a group. base, Ethyl, n-butyl, n-octyl, and cyclohexyl, etc., among these, more preferably a substituent such as a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group or a hydroxynaphthyl group. An aromatic group or an unsubstituted aromatic group.

Further, in the formula (7), X2 is an organic group bonded to Y2 and Y3. Similarly, X3 is an organic group bonded to the groups Y4 and Y5. Y2 and Y3 are the bases of proton-donating protons, and the groups Y2 and Y3 in the same molecule are bonded to the ruthenium atoms to form a chelate structure. Similarly, Y4 and Y5 are groups in which a proton-donating group releases protons, and groups Y4 and Y5 in the same molecule are bonded to a ruthenium atom to form a chelate structure. The radicals X2 and X3 may be identical to each other or different, and the radicals Y2, Y3, Y4, and Y5 may be identical to each other or different. The group represented by -Y2-X2-Y3- and -Y4-X3-Y5- in the general formula (7) is a group in which a proton is supplied to the body to release two protons. The proton donor is preferably an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule, and more preferably an aromatic compound having at least two carboxyl groups or hydroxyl groups on the carbon constituting the aromatic ring, and more preferably An aromatic compound having at least two hydroxyl groups on a carbon adjacent to the aromatic ring. For example, catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2'-biphenol, 1,1-di-2-naphthol, water Salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chlorodecanoic acid, tannic acid, 2-hydroxybenzyl alcohol, 1,2-cyclohexanediol, 1,2-propanediol, And glycerin, etc. Among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferable from the viewpoint of the balance between the availability of the raw material and the hardening promoting effect.

Further, Z1 in the formula (7) represents an organic group having an aromatic ring or a hetero ring or an aliphatic group, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. An aliphatic hydrocarbon group such as octyl group or a reactive hydrocarbon group such as an aromatic hydrocarbon group such as a phenyl group, a benzyl group, a naphthyl group or a biphenyl group; a glycidoxypropyl group, a mercaptopropyl group, an aminopropyl group or a vinyl group; Wait. In this Among them, in terms of thermal stability, a methyl group, an ethyl group, a phenyl group, a naphthyl group, and a biphenyl group are more preferable.

The method for producing the adduct of the oxime compound and the decane compound is not particularly limited, and for example, it can be carried out as follows. First, a proton such as phenyltrimethoxydecane or a proton such as 2,3-dihydroxynaphthalene is added to a flask containing methanol, and the mixture is dissolved, and then sodium methoxide is added dropwise with stirring at room temperature. Methanol solution. Further, a solution obtained by dissolving a tetrasubstituted phosphonium halide such as tetraphenylphosphonium bromide prepared in methanol in advance is added dropwise thereto under stirring at room temperature to precipitate crystals. When the precipitated crystals are filtered, washed with water, and vacuum dried, an adduct of a ruthenium compound and a decane compound is obtained.

In the present embodiment, the content of the hardening accelerator (D) in the under molding material for the compression molding die is preferably 0.05% by mass or more, and more preferably 0.1% by mass or more, based on the entire underfill material for the compression molding die. More preferably, it is 0.15 mass% or more. When the content of the hardening accelerator (D) is at least the above lower limit value, the hardenability at the time of compression molding can be effectively improved.

On the other hand, the content of the hardening accelerator (D) in the underfill material for compression molding is preferably 1% by mass or less, and more preferably 0.5% by mass or less based on the entire underfill material for compression molding. When the content of the hardening accelerator (D) is at most the above upper limit value, fluidity at the time of compression molding can be improved.

((E) coupling agent)

The mold underfill material for compression molding may further contain, for example, a coupling agent (E). As the coupling agent (E), for example, various decane-based compounds such as epoxy decane, mercapto decane, amino decane, alkyl decane, ureido decane, vinyl decane, and methacryl decane, titanium compounds, and aluminum chelates can be used. A known coupling agent such as a compound or an aluminum/zirconium compound. If the coupling agents are exemplified, they can be listed For example: vinyl trichloromethane, vinyl trimethoxy decane, vinyl triethoxy decane, vinyl tris (β-methoxyethoxy) decane, γ-methyl propylene methoxy propyl trimethoxide Baseline, β-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, γ-glycidoxypropyltrimethoxydecane, γ-glycidoxypropyltriethoxydecane , γ-glycidoxypropylmethyldimethoxydecane, γ-methylpropenyloxypropylmethyldiethoxydecane, γ-methylpropenyloxypropyltriethoxy Decane, vinyltriethoxydecane, γ-mercaptopropyltrimethoxydecane, γ-aminopropyltriethoxydecane, γ-anilinopropyltrimethoxydecane, γ-anilinopropyl Methyldimethoxydecane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxydecane, N-β-(aminoethyl)-γ-aminopropyltrimethoxy Decane, N-β-(aminoethyl)-γ-aminopropyltriethoxydecane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxydecane, N-phenyl-γ-aminopropyltrimethoxydecane, γ-(β-aminoethyl)aminopropyldimethoxymethyl矽, N-(trimethoxymethyl propyl) ethylene diamine, N-(dimethoxymethyl decyl isopropyl) ethylene diamine, methyl trimethoxy decane, dimethyl dimethoxy Decane, methyltriethoxydecane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxydecane, γ-chloropropyltrimethoxydecane, hexa Dioxane, vinyltrimethoxydecane, γ-mercaptopropylmethyldimethoxydecane, 3-isocyanatepropyltriethoxydecane, 3-propenyloxypropyltrimethoxydecane, 3 - a decane coupling agent such as a hydrolyzate of triethoxysulfonyl-N-(1,3-dimethyl-butylene) propylamine; isopropyl triisostearate isopropyl titanate, tris(dioctyl coke) Phosphonium oxy) isopropyl titanate, isopropyl tris(N-aminoethyl-aminoethyl) titanate, tetraoctyl bis(di-tridecylphosphonium oxy) titanate , bis(di-tridecylphosphonium oxy)titanate tetrakis(2,2-diallyloxymethyl-1-butyl) ester, bis(dioctylpyrophosphoniumoxy) hydroxy Titanium acetate, bis(dioctylpyridinium oxy)titanate, octyl octyl titanate, dimethyl methacrylate isostearyl ruthenium Isopropyl acrylate, isopropyl tris(dodecylbenzenesulfonyl) titanate, isostearyl decyldipropenyl titanate Isopropyl ester, tris(dioctylphosphoric acid) isopropyl titanate, (triisopropylphenylphenyl) titanate, bis(dioctylphosphonium oxy) titanate, etc. A titanate coupling agent. These may be used alone or in combination of two or more. Among these, a decane compound of an epoxy decane, a mercapto decane, an amino decane, an alkyl decane, a urea decane, or a vinyl decane is more preferable. Further, from the viewpoint of more effectively improving the filling property or the formability, it is particularly preferable to use a secondary aminodecane represented by N-phenyl-γ-aminopropyltrimethoxydecane.

In the present embodiment, the content of the coupling agent (E) in the under molding material for the compression molding die is preferably 0.1% by mass or more, and more preferably 0.15% by mass or more based on the entire underfill material for the compression molding die. When the content of the coupling agent (E) is at least the above lower limit value, the dispersibility of the inorganic filler (C) can be improved.

On the other hand, the content of the coupling agent (E) in the under molding material for the compression molding die is preferably 1% by mass or less, and more preferably 0.5% by mass or less based on the entire underfill material for the compression molding die. When the content of the coupling agent (E) is at most the above upper limit value, the fluidity at the time of compression molding can be improved, and the filling property or the moldability can be improved.

In the underfill material for the mold for compression molding, a hydrotalcite plasma trapping agent may be appropriately blended as needed; a coloring agent such as carbon black or colcothar; a low stress component such as polyoxyxene rubber; and a natural wax such as carnauba wax. Synthetic wax such as wax, montanic acid ester wax, higher fatty acid such as zinc stearate, metal salt or paraffin, etc.; aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, phosphorus A flame retardant such as nitrile; various additives such as antioxidants.

The mold underfill material for compression molding of the present embodiment can be obtained by mixing and kneading the above-mentioned components, and then using various methods such as pulverization, granulation, extrusion cutting, and sieving, or a combination thereof. Into the powder and granules. As a method of obtaining a powder or granule, for example The following methods and the like are used: premixing each raw material component by a mixer, heating and kneading it by a kneading machine such as a roll, a kneader or an extruder, and then moving to a cylindrical outer peripheral portion and a disk having a plurality of small holes The inside of the rotor formed on the bottom surface of the shape is supplied with the resin composition after melt-kneading, and the centrifugal force obtained by rotating the rotor causes the resin composition to pass through the small holes to obtain the powder or granules (centrifugal milling method); After the kneading in the same manner as above, the coarse particles and the fine powder are removed by the cooling and pulverizing steps to obtain the granules (crushing and sieving method); after premixing the respective raw materials with the mixer An extruder equipped with a nozzle having a plurality of small holes at a tip end portion of the screw is used for heating and kneading, and is cut by a cutter that is slidably rotated substantially parallel to the die face to be disposed in the die. The small hole is a molten resin extruded in a strand shape to obtain a powder or granule (hereinafter also referred to as "thermal cutting method"). In either method, a mold base material for compression molding having a desired particle size distribution can be obtained by selecting kneading conditions, centrifugation conditions, sieving conditions, cutting conditions, and the like.

Next, the semiconductor package 100 of the present embodiment will be described.

Fig. 1 is a cross-sectional view showing a semiconductor package 100 of the present embodiment. The semiconductor package 100 includes a substrate 10 , a semiconductor element 20 , and a sealing material 30 . The semiconductor element 20 is disposed on the substrate 10. In FIG. 1, a case where the semiconductor element 20 is flip-chip mounted on the substrate 10 via the bumps 22 is exemplified. The sealing material 30 seals the semiconductor element 20 and fills the gap 24 between the substrate 10 and the semiconductor element 20. The sealing material 30 is obtained by molding the underfill material for the compression molding die by a compression molding method. In this case, the semiconductor element 20 can be sealed with a mold base underfill for compression molding excellent in filling property, and the gap 24 can be filled therein, whereby the semiconductor package 100 excellent in reliability can be realized.

The semiconductor package 100 is manufactured, for example, in the following manner. First, on the substrate 1b, The semiconductor element 20 is disposed by the spacers 22. Then, the semiconductor element 20 is sealed by the compression molding method using the under molding material for compression molding of the present embodiment, and the gap 24 between the substrate 10 and the semiconductor element 20 is filled. Thereby, the sealing material 30 is formed. The compression molding method can be carried out, for example, at a mold temperature of 120 to 185 ° C, a molding pressure of 1 to 12 MPa, and a curing time of 60 seconds to 15 minutes using a compression molding machine.

Next, the structure 102 of the present embodiment will be described.

Fig. 2 is a cross-sectional view showing the structure 102 of the present embodiment. The structure 102 is a molded article formed by MAP molding. Therefore, a plurality of semiconductor packages are obtained by singulating the structure 102 in units of semiconductor elements.

The structure 102 includes a substrate 10 , a plurality of semiconductor elements 20 , and a sealing material 30 . The plurality of semiconductor elements 20 are disposed on the substrate 10. In FIG. 2, the case where each semiconductor element 20 is flip-chip mounted on the substrate 10 via the bump 22 is exemplified. The sealing material 30 seals the plurality of semiconductor elements 20 and fills the gap 24 between the substrate 10 and each of the semiconductor elements 20. The sealing material 30 is obtained by molding the underfill material for the compression molding die by a compression molding method. In this case, each of the semiconductor elements 20 can be sealed using a mold base material for compression molding excellent in filling property, and each gap 24 can be filled.

The structure 102 is manufactured, for example, in the following manner. First, a plurality of semiconductor elements 20 are arranged on a substrate 10. Each of the semiconductor elements 20 is mounted on the substrate 10 via a bump 22, for example. Then, the plurality of semiconductor elements 20 are sealed by the compression molding die underfill material of the present embodiment by the compression molding method, and the gap 24 between the substrate 10 and each of the semiconductor elements 20 is filled. Thereby, the sealing material 30 is formed. The compression molding method can be, for example, a compression molding machine at a mold temperature of 120 to 185 ° C, a molding pressure of 1 to 12 MPa, and a curing time of 60 seconds to 15 minutes. Under the pieces.

[Examples]

Next, an embodiment of the present invention will be described.

(Preparation of mold underfill material)

First, each raw material obtained by blending according to Table 1 was kneaded at 110 ° C for 7 minutes using a 2-axis kneading extruder. Next, after degassing and cooling, the obtained kneaded material was pulverized by a pulverizer to obtain a granule. In Examples 1 to 7 and Comparative Examples 1 to 3, the powder or granules obtained in this manner were further sieved, whereby a mold underfill material for compression molding was obtained. Further, in Comparative Example 4, the above-mentioned material which was pulverized to a level capable of tableting was subjected to tableting, thereby obtaining a flat-shaped transfer molding underfill material. The details of each component in Table 1 are as follows. Further, the unit in Table 1 is mass%.

(A) Epoxy resin

Epoxy Resin 1: Phenol aralkyl type epoxy resin with a benzene skeleton (manufactured by Nippon Kayaku Co., Ltd., NC-3000)

Epoxy Resin 2: Biphenyl type epoxy resin (Mitsubishi Chemical Co., Ltd., YX-4000)

(B) hardener

Hardener 1: Phenol aralkyl resin with a benzene backbone (manufactured by Nippon Kayaku Co., Ltd., GPH-65)

Hardener 2: Trisphenol methane phenol resin (Minghe Chemical Co., Ltd., MEH-7500)

(C) inorganic filler

Cerium oxide 1: molten spherical ceria (mode diameter R = 10 μm, particle size R _max = 18 μm, R / R _max = 0.56)

Ceria 2: molten spherical ceria (mode diameter R=5 μm, particle size R _max =10 μm, R/R _max =0.5)

Ceria 3: molten spherical ceria (mode diameter R=10 μm, particle size R _max =24 μm, R/R _max =0.42)

(D) hardening accelerator

Hardening accelerator 1: a compound represented by the following formula (8)

Hardening accelerator 2: a compound represented by the following formula (9)

Hardening accelerator 3: triphenylphosphine

(E) coupling agent

Coupler 1: γ-glycidoxypropyltrimethoxydecane (GPS-M manufactured by Chisso)

Coupler 2: N-phenyl-γ-aminopropyltrimethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-573)

(F) Other ingredients

Ion trapping agent: hydrotalcite (manufactured by Xiehe Chemical Industry Co., Ltd., DHT-4H)

Release agent: montanic acid ester wax (manufactured by Clariant Japan, WE-4M)

Flame Retardant: Aluminum Hydroxide (manufactured by Sumitomo Chemical Co., Ltd., CL-303)

Colorant: carbon black (Mitsubishi Chemical Co., Ltd., MA-600)

(Measurement of time T (5))

For each of Examples 1 to 7 and Comparative Examples 1 to 4, a vulcanizer (manufactured by Orientec, JSR IVPS type vulcanizer) was used, and the hardening of the underfill material of the mold was measured over time at a mold temperature of 175 ° C. Torque. Based on the measurement result, the time T (5) from the start of measurement to 5% of the torque (defined as the maximum torque) at the time of 300 seconds was calculated. The unit in Table 1 is seconds.

(Measurement of viscosity η)

For each of Examples 1 to 7 and Comparative Examples 1 to 4, a high-performance flow tester (manufactured by Shimadzu Corporation, CFT-500C) was used, and the temperature was 175 ° C, the load was 40 kgf (piston area: 1 cm ² ), The apparent viscosity η of the melted mold underfill material was measured under the test conditions of a die orifice diameter of 0.50 mm and a die length of 1.00 mm. The viscosity η is calculated by the following calculation formula. In the calculation formula, Q is the flow rate of the underfill material of the mold flowing per unit time. The unit in Table 1 is Pa ‧ seconds.

η = (4πDP / 128LQ) × 10 ^-3 (Pa ‧ seconds)

η: apparent viscosity

D: die hole diameter (mm)

P: test pressure (Pa)

L: die length (mm)

Q: flow rate (cm ³ / sec)

(filling)

For each of the examples and the comparative examples, the filling property was evaluated as follows.

In Examples 1 to 7 and Comparative Examples 1 to 3, a compression molding machine (manufactured by TOWA Co., Ltd., PMC 1040) was used under the conditions of a mold temperature of 175 ° C, a molding pressure of 3.9 MPa, and a curing time of 90 seconds. Mold Array Package BGA for compression molding, and 3×10 185×65mm×0.36mmt Bismaleimide-III A resin/glass cloth substrate, a wafer of 10×10 mm×200 μmt, and a mold resin of 180×60 mm×450 μmt, a gap between the substrate and the wafer of 70 μm and 30 μm, and a bump interval of 200 μm) were sealed and formed.

In Comparative Example 4, a transfer molding machine (manufactured by TOWA Co., Ltd., Y series) was used, and the mold temperature was 175 ° C, the injection pressure was 6.9 MPa, and the curing time was 90 seconds. Wafer type MAPBGA molding.

Then, using a ultrasonic flaw detector (manufactured by Hitachi Construction Machinery Co., Ltd., FS300), the filling property of the underfill material of the mold at the gap between the formed substrate and the wafer was observed. In Table 1, the case where the mold underfill material was filled with no gap between the substrate and the wafer was evaluated as ○, and the evaluation was evaluated as × for the case where there was no filling between the substrate and the wafer. Further, when bulging was observed on the surface of the package due to poor curing, it was considered that molding was impossible. Table 1 shows the results of a case where the gap between the substrate and the wafer is 70 μm and a gap between the substrate and the wafer of 30 μm.

(ash uniformity)

For each of the examples and the comparative examples, the ash uniformity was evaluated as follows.

First, the substrate is changed to a metal plate of the same size, and the surface of the metal plate is thinly coated. In addition to the release agent, a flip chip type MAPBGA was prepared in the same manner as the above-described filling evaluation. Then, using the same molding machine as the above-described filling property evaluation, the flip chip type MAPBGA was hermetically sealed using the mold underfill material under the same conditions.

Then, the resin portions on the long sides of the molded article obtained from the outer edge of 5 mm were cut out, and members other than the resin were removed and freeze-pulverized, respectively, to obtain two samples respectively corresponding to the two long sides. Next, each sample was heated to 500 ° C at a temperature increase rate of 30 ° C / min using a differential thermal balance, and the weight of the residue was measured for 30 minutes. This measurement was repeated three times. Next, for each sample, the value obtained by dividing the weight of the residue after three measurements by the original weight was defined as ash (% by mass). Next, the ash uniformity was evaluated based on the value obtained by dividing the ash of one of the samples having the smaller ash by the ash of the other sample having the larger ash. The results are shown in Table 1.

In Examples 1 to 7, the filling properties were good. Among these, Examples 1 to 5 exhibited superior ash uniformity than Examples 6 and 7. On the other hand, in Comparative Examples 1 and 2, the filling property under the wafer at the time of MAP molding by the compression molding method was insufficient. In Comparative Example 3, the mold underfill material of the large-area MAP molded article was insufficient in hardenability to cause bulging. In Comparative Example 4 in which MAP molding by transfer molding was performed, it was found that the filling property under the wafer of the slit was insufficient. Further, in Comparative Example 4, it was found that the ash uniformity of the large-area MAP formation was less than 0.9, and sufficient ash uniformity was not obtained. It can be seen that the present invention is based on the formation of a large-area MAP and the formation of a mold underfill type, which is superior to the previous transfer molding, particularly in terms of filling property and ash uniformity under the wafer for the slit. Significant effect.

Claims (9)

A mold underfill material for compression molding, which seals a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element, and contains: an epoxy resin (A) and a hardener (B) And the inorganic filler (C), and the underfill material for the compression molding mold is a powder or granule, and when the measurement is performed at a mold temperature of 175 ° C using a curelastometer, the measurement is started until the maximum is reached. The time T(5) until 5% of the torque is 25 seconds or more and 100 seconds or less. The mold underfill material for compression molding according to the first aspect of the invention, wherein the viscosity η at 175 ° C measured by a high-pressure flow tester is 3.5 Pa ‧ or more and 15 Pa ‧ or less. The patent range compression as item 2 with a filler material forming the mold bottom, wherein the time T (5) / η is a viscosity of 2 Pa or more and 30Pa ^{-1 -1} or less. The mold underfill material for compression molding according to any one of claims 1 to 3, wherein the inorganic filler (C) is observed from a maximum particle diameter side of a volume-based particle size distribution, and the cumulative frequency is 5%. The particle diameter R _max is 8 μm or more and 35 μm or less. The mold underfill material for compression molding according to claim 4, wherein the inorganic filler (C) has a particle diameter corresponding to a maximum peak of a volume-based particle size distribution as a mode diameter R, R/R _max It is 0.40 or more. The under molding material for compression molding of any one of claims 1 to 3 The inorganic filler (C) is silica. A semiconductor package obtained by sealing a semiconductor element disposed on a substrate and filling the substrate with the mold underfill material for compression molding according to any one of claims 1 to 6 A gap between semiconductor components. A structure obtained by sealing a plurality of semiconductor elements disposed on a substrate and filling the substrate by using a mold base material for compression molding according to any one of claims 1 to 6 A gap with each of the semiconductor elements. A method of manufacturing a semiconductor package, comprising the steps of: arranging a semiconductor element on a substrate by interposing a bump; and using a compression molding method, the compression molding die according to any one of claims 1 to 6. The underfill material seals the semiconductor element and fills a gap between the substrate and the semiconductor element.