KR102367126B1 - Mold underfill material for compression molding, semiconductor package, structure and method for manufacturing semiconductor package - Google Patents

Abstract

A mold underfill material for compression molding that encapsulates a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element, an epoxy resin (A), a curing agent (B), and an inorganic filler ( Including C), it is a powder and granular material, and when measured under the conditions of a mold temperature of 175° C. using a curastometer, the time T(5) from the start of the measurement to reaching 5% of the maximum torque is 25 seconds greater than or equal to 100 seconds.

Description

MOLD UNDERFILL MATERIAL FOR COMPRESSION MOLDING, SEMICONDUCTOR PACKAGE, STRUCTURE AND METHOD FOR 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 the semiconductor package.

In the semiconductor package formed by mounting a semiconductor element on a board|substrate, the mold underfill material which performs filling of the gap between a board|substrate and a semiconductor element, and sealing of a semiconductor element collectively may be used. As a technique regarding a mold underfill material, the thing of patent document 1 is mentioned, for example.

Patent Document 1 is a technology related to 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.

Japanese Patent Laid-Open No. 2011-132268

When filling of the gap between a board|substrate and a semiconductor element and sealing of a semiconductor element were performed collectively using a mold underfill material, the fillability in the said gap|interval may not fully be acquired. For this reason, the mold underfill material excellent in fillability is calculated|required.

According to the present invention,

A mold underfill material for compression molding that encapsulates a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element,

an epoxy resin (A);

a curing agent (B);

an inorganic filler (C);

It is a granular,

A mold underfill material for compression molding whose time T(5) from the start of measurement to reaching 5% of the maximum torque is 25 seconds or more and 100 seconds or less when measured using a curastometer under the conditions of a mold temperature of 175°C is provided

ADVANTAGE OF THE INVENTION According to this invention, the semiconductor package obtained by sealing the semiconductor element arrange|positioned on a board|substrate and filling the clearance gap between the said board|substrate and the said semiconductor element using the mold underfill material for compression molding mentioned above is provided.

According to the present invention, there is provided a structure obtained by encapsulating a plurality of semiconductor elements disposed on a substrate using the aforementioned compression molding underfill material and filling a gap between the substrate and each of the semiconductor elements. do.

According to the present invention,

A step of arranging a semiconductor element on a substrate with bumps interposed therebetween;

There is provided a method for manufacturing a semiconductor package, comprising the step of sealing the semiconductor element with the mold underfill material for compression molding using a compression molding method and filling a gap between the substrate and the semiconductor element.

ADVANTAGE OF THE INVENTION According to this invention, the mold underfill material excellent in filling property can be implement|achieved.

The above-mentioned objective and other objects, characteristics, and advantages become clearer by the suitable embodiment demonstrated below, and the following drawings accompanying it.
BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the semiconductor package which concerns on this embodiment.
2 is a cross-sectional view showing a structure according to the present embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is demonstrated using drawings. In addition, in all the drawings, the same code|symbol is attached|subjected to the same component, and description is abbreviate|omitted suitably.

(First embodiment)

The mold underfill material according to the present embodiment is a mold underfill material for compression molding that seals the semiconductor element disposed on the substrate and fills the gap between the substrate and the semiconductor element. The mold underfill material for compression molding contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C). In addition, the mold underfill material for compression molding is a powder or granular material. In addition, when the mold underfill material for compression molding is measured under the conditions of a mold temperature of 175 degreeC using a curastometer, the time T(5) from the start of measurement to reaching 5% of the maximum torque is 25 seconds greater than or equal to 100 seconds.

It is conceivable that the sealing of the semiconductor element using the mold underfill material and the filling of the gap located under the semiconductor element are performed by, for example, a transfer molding method. However, in this case, it may become difficult to stably obtain the excellent filling property with respect to the said clearance gap. This was particularly remarkable in the case of large-area MAP molding. In view of such circumstances, the present inventor studied performing sealing molding of a mold underfill material using the compression molding method. However, even in such a case, the more excellent filling property with respect to the clearance gap between a board|substrate and a semiconductor element was calculated|required.

The present inventors control the curing characteristics measured by the curastometer with respect to the mold underfill material, whereby the sealing of the semiconductor element and the filling of the gap located under the semiconductor element are collectively performed by the compression molding method. discovered something new to improve. In the present embodiment, based on such findings, the time T(5) from the start of measurement to reaching 5% of the maximum torque when measured under the condition of a mold temperature of 175°C using a curastometer is , to provide a mold underfill material for compression molding that is 25 seconds or more and 100 seconds or less. Thereby, it becomes possible to implement|achieve the mold underfill material excellent in fillability.

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

First, the mold underfill material for compression molding is demonstrated.

The mold underfill material for compression molding encapsulates the semiconductor element disposed on the substrate and fills the gap between the substrate and the semiconductor element. Sealing of a semiconductor element and filling with respect to the clearance gap between a board|substrate and a semiconductor element are performed collectively using the compression molding method. Thereby, the mold underfill material excellent in fillability and ash content uniformity can be shape|molded. Such an effect is obtained especially notably, for example, in sealing molding of a large area, such as MAP molding.

The board|substrate is a wiring board, such as an interposer, for example. Moreover, the semiconductor element is flip-chip mounted with respect to a board|substrate, for example. Formed by sealing and filling using a mold underfill material for compression molding, for example, is a semiconductor package such as BGA (Ball Grid Array) or CSP (Chip Size Package), and recently MAP ( It also relates to a structure formed by molding (Mold Array Package).

The mold underfill material for compression molding is a powder or granular material. Thereby, it becomes possible to shape|mold the mold underfill material excellent in fillability and ash content uniformity using the compression molding method. In addition, that the mold underfill material for compression molding is a powder or granular material refers to the case of either a powder form or a granular form. The mold underfill material for compression molding according to the present embodiment can be, for example, granular.

Further, according to compression molding using the powder underfill material for compression molding of the present embodiment, which is a powder or granular material, excellent filling properties and ash content uniformity can be realized as compared with transfer molding using a tablet-shaped mold underfill material rather than a powder or granular material.

The mold underfill material for compression molding in the present embodiment has a particle size distribution measured by sieving using a JIS standard sieve. It is preferable that this is 5 weight% or less, and it is more preferable that it is 3 weight% or less. By making the ratio of fine powder with a particle diameter of less than 106 μm equal to or less than the above upper limit, the powdery material does not become a lump when dispersed on the mold and melts uniformly, thereby suppressing partial gelation and uneven curing. For this reason, it becomes possible to aim at the improvement of the ash content uniformity and moldability at the time of compression molding.

Further, the mold underfill material for compression molding in the present embodiment has a particle size distribution measured by sieving using a JIS standard sieve. It is preferable that it is 3 weight% or less, and, as for the ratio, it is more preferable that it is 2 weight% or less. By making the ratio of the granulation with a particle diameter of 2 mm or more into below the said upper limit, dispersion nonuniformity at the time of compression molding can be reduced, and the uniformity of the thickness of cured resin can be aimed at. In addition, when dispersed on a mold, the powder or granular material is uniformly melted without becoming a lump, suppressing partial gel and curing unevenness, and improving ash content uniformity and moldability during compression molding. will do

As a method for measuring the particle size distribution of the mold underfill material for compression molding as described above, using a JIS standard sieve having openings of 2.00 mm, 1.00 mm and 106 μm of mesh provided in a rotary tap type sieve vibrator, these sieves are sieved over 20 minutes. Classification by passing a 40 g sample through a sieve while vibrating (number of hammer strokes: 120 times/min) As an example, the method of calculating|requiring the ratio (weight%) of the fine powder passing through a sieve is mentioned.

Moreover, when this method is used, there is a possibility that the particle|grains with a high aspect-ratio may pass through each sieve. For this reason, in the measurement of the particle size distribution by the above method, for example, for convenience, the weight % of each component classified according to the predetermined conditions is a mold underfill material for compression molding of particles having a particle size corresponding to each component. It can be defined as a ratio to the whole.

In this embodiment, when the mold underfill material for compression molding is measured under the condition of a mold temperature of 175° C. using a curastometer, time T (5) from the start of measurement to reaching 5% of the maximum torque is 25 seconds or more and 100 seconds or less. Here, for example, the torque at 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 more, it is possible to improve the filling properties of the gap between the substrate and the semiconductor element during compression molding. On the other hand, by making time T(5) into 100 second or less, sufficient hardenability is realizable in compression molding. In this way, by controlling the curing characteristics measured by the curastometer, it is possible to realize a molded underfill material excellent in filling properties and curing properties at the time of compression molding. Further, from the viewpoint of improving the filling properties and curing properties, the time T(5) is more preferably 30 seconds or more and 90 seconds or less, and 45 seconds or more and 80 seconds or less in consideration of the additional stability of the filling properties and ash uniformity is particularly preferable. Do.

In addition, the time T(5) can be controlled by appropriately adjusting the type and content of each component contained in the mold underfill material for compression molding, the particle size distribution of the mold underfill material for compression molding, and the like, for example. In this embodiment, for example, when the kind and content of a hardening|curing agent (B) or an inorganic filler (C) contain a hardening accelerator (D) or a coupling agent (E), adjusting these kind and content is mentioned can

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

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

In the present embodiment, for example, using a solidifying flow tester, melt compression measured under test conditions of a temperature of 175° C., a load of 40 kgf (piston area 1 cm ² ), a die hole diameter of 0.50 mm, and a die length of 1.00 mm The apparent viscosity of the molding underfill material can be defined as the viscosity η. In this case, the viscosity η can be calculated from, for example, the following formula. In the formula, Q is the flow rate of the mold underfill material flowing per unit time.

η=(4πDP/128LQ)×10 ^-3 (Pa sec)

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, it is possible to improve the balance of the fillability, moldability, fluidity, and curability of the mold underfill material for compression molding. From the viewpoint of improving their balance, the time T(5)/viscosity η is, for example, preferably 2Pa ^-1 or more and 30 Pa ^-1 or less, more preferably 4 Pa ^-1 or more and 25 Pa ^-1 or less, and 5 Pa ^-1 It is especially preferable that it is more than 20 Pa ^-1 or less. By making time T(5)/viscosity (eta) more than the said lower limit, fluidity|liquidity and filling property can be improved with favorable balance. Moreover, by making time T(5)/viscosity (eta) or less into the said upper limit, it becomes possible to aim at the improvement of fillability, suppressing the fall of sclerosis|hardenability and moldability reliably. In the present invention, especially in a large-area structure such as MAP molding, in order to achieve both filling and uniform formability in a small space between the semiconductor element and the substrate, the time T (5 )/the value of viscosity η is 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, it becomes possible to shape|mold the mold underfill material for compression molding using the compression molding method.

((A) Epoxy resin)

As an epoxy resin (A), the monomer, oligomer, and polymer which have two or more epoxy groups in 1 molecule can be used, The molecular weight and molecular structure are not specifically limited.

In this embodiment, as an epoxy resin (A), For example, a biphenyl type epoxy resin; Bisphenol-type epoxy resins, such as a bisphenol A epoxy resin, a bisphenol F-type epoxy resin, and a tetramethyl bisphenol F-type epoxy resin; stilbene-type epoxy resin; novolac-type epoxy resins such as phenol novolak-type epoxy resins and cresol novolak-type epoxy resins; polyfunctional epoxy resins such as triphenolmethane-type epoxy resins and alkyl-modified triphenolmethane-type epoxy resins; Aralkyl type epoxy resins, such as a phenol aralkyl type epoxy resin which has a phenylene frame|skeleton, and a phenol aralkyl type epoxy resin which has a biphenylene frame|skeleton; naphthol type epoxy resins such as dihydroxynaphthalene type epoxy resins and epoxy resins obtained by glycidyl etherification of a dimer of dihydroxynaphthalene; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; Glued cyclic hydrocarbon compound modified phenol type epoxy resins, such as dicyclopentadiene modified phenol type epoxy resin, are mentioned, These may be used individually by 1 type, or may use 2 or more types together. Among these, it is preferable that a bisphenol type epoxy resin such as a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a tetramethyl bisphenol F type epoxy resin, and a stilbene type epoxy resin have crystallinity. Do.

As the epoxy resin (A), containing at least one selected from the group consisting of an epoxy resin represented by the following formula (1), an epoxy resin represented by the following formula (2), and an epoxy resin represented by the following formula (3) It is particularly preferred to use

[Formula 1]

(In formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² is a phenylene group; Represent any group of biphenylene group or naphthylene _{group.R a} and Rb each independently represent a hydrocarbon group having 1 to 10 carbon atoms.g is an integer from 0 to 5, and h is an integer from 0 to 8 n ³ represents the degree of polymerization, and the average value is 1 to 3)

[Formula 2]

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

[Formula 3]

(In formula (3), two or more 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 is 0 to 4)

In the present embodiment, the content of the epoxy resin (A) in the mold underfill material for compression molding is preferably 3% by weight or more, more preferably 4% by weight or more, based on the entire mold underfill material for compression molding, It is especially preferable that it is 6 weight% or more. By making content of an epoxy resin (A) more than the said lower limit, at the time of compression molding, sufficient fluidity|liquidity can be implement|achieved and the improvement of fillability and moldability can be aimed at.

On the other hand, it is preferable that it is 30 weight% or less with respect to the whole mold underfill material for compression molding, and, as for content of the epoxy resin (A) in the mold underfill material for compression molding, it is more preferable that it is 20 weight% or less. By carrying out content of an epoxy resin (A) below the said upper limit, moisture reliability and reflow resistance can be improved with respect to the semiconductor package formed using the mold underfill material for compression molding.

((B) curing agent)

As a hardening|curing agent (B) contained in the resin composition for sealing, it can divide roughly into 3 types, for example of a polyaddition hardening|curing agent, a catalyst-type hardening|curing agent, and a condensation-type hardening|curing agent.

Examples of the polyaddition curing agent used in the curing agent (B) include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and metaxylenediamine (MXDA), and diaminodiphenylmethane (DDM) polyamine compounds containing dicyandiamide (DICY), organic acid dihydrazide, etc. in addition to aromatic polyamines such as , m-phenylenediamine (MPDA) and diaminodiphenylsulfone (DDS); Alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and aromatic acids such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA) acid anhydrides including anhydrides and the like; Phenolic resin-type hardening|curing agents, such as a novolak-type phenol resin and polyvinyl phenol; polymercaptan compounds such as polysulfide, thioester, and thioether; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; Organic acids, such as a carboxylic acid containing polyester resin, etc. are mentioned.

Examples of the catalyst-type curing agent used for the curing agent (B) include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol (DMP-30); imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole (EMI24); Lewis acids, such as a BF3 complex, etc. are mentioned.

As a condensation-type hardening|curing agent used for a hardening|curing agent (B), For example, a resol-type phenol resin; urea resins such as methylol group-containing urea resins; A melamine resin like a methylol group containing melamine resin, etc. are mentioned.

Among these, a phenolic resin hardening|curing agent is preferable from a viewpoint of improving the balance with respect to a flame retardance, moisture resistance, an electrical characteristic, sclerosis|hardenability, storage stability, etc. As a phenol resin hardening|curing agent, the monomer, oligomer, and polymer which have two or more phenolic hydroxyl groups in 1 molecule can be used, The molecular weight and molecular structure are not specifically limited.

As a phenol resin type hardening|curing agent used for a hardening|curing agent (B), For example, novolak-type phenol resins, such as a phenol novolak resin, a cresol novolak resin, and a bisphenol novolak resin; polyvinylphenol; polyfunctional phenol resins such as triphenolmethane type phenol resins; modified phenol resins such as terpene-modified phenol resins and dicyclopentadiene-modified phenol resins; Aralkyl-type phenol resins, such as a phenol aralkyl resin which has a phenylene skeleton and/or a biphenylene skeleton, and a naphthol aralkyl resin which has a phenylene skeleton and/or a biphenylene skeleton; Bisphenol compounds, such as bisphenol A and bisphenol F, etc. are mentioned, These may be used individually by 1 type, and may use 2 or more types together. Among these, it is more preferable to use a polyfunctional type phenol resin or an aralkyl type phenol resin from a viewpoint of improving the sclerosis|hardenability of the mold underfill material for compression molding.

In the present embodiment, the content of the curing agent (B) in the mold underfill material for compression molding is preferably 1% by weight or more, more preferably 2% by weight or more, based on the entire mold underfill material for compression molding, 3 % by weight or more is particularly preferred. By carrying out content of a hardening|curing agent (B) more than the said lower limit, at the time of compression molding, the outstanding fluidity|liquidity can be implement|achieved and the improvement of fillability and moldability can be aimed at.

On the other hand, the content of the curing agent (B) in the compression molding mold underfill material is preferably 25% by weight or less, more preferably 15% by weight or less, and 10% by weight or less with respect to the entire mold underfill material for compression molding. Especially preferred. By carrying out content of a hardening|curing agent (B) below the said upper limit, moisture reliability and reflow resistance can be improved with respect to the semiconductor package formed using the mold underfill material for compression molding.

((C) inorganic filler)

Although it does not specifically limit as a constituent material of an inorganic filler (C), For example, Silica, such as fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, etc. are mentioned, Any 1 or more of these can be used. . Among these, from a viewpoint of being excellent in versatility, it is more preferable to use silica, and it is especially preferable to use fused silica. Moreover, it is preferable that it is spherical, and, as for an inorganic filler (C), it is preferable that it is spherical silica. Thereby, the fluidity|liquidity of the mold underfill material for compression molding at the time of compression molding can be improved effectively.

The inorganic filler (C) has, for example, a particle size R _max of 8 µm or more and 35 µm or less with a cumulative frequency of 5% as viewed from the maximum particle size side of the volume-based particle size distribution. Thereby, the dispersibility of an inorganic filler (C) can be improved and ash content uniformity can be improved effectively. Moreover, the fluidity|liquidity of the mold underfill material for compression molding can also be improved. From a viewpoint of improving the balance of ash content uniformity and fluidity|liquidity effectively, it is more preferable that particle diameter _Rmax are 10 micrometers or more and 25 micrometers or less, It is especially preferable that they are 11 micrometers or more and 23 micrometers or less.

In addition, the inorganic filler (C) makes the mode diameter R the particle diameter corresponding to the maximum peak of the volume-based particle size distribution, and preferably has a mode diameter R of 1 μm or more and 24 μm or less, more preferably 3 μm or more and 24 μm or less, more preferably 4.5 μm It is especially preferable that it is more than 24 micrometers. Thereby, at the time of compression molding, the filling with respect to the narrow gap between a board|substrate and a semiconductor element and the uniform moldability in MAP molding of a large area can be improved more effectively.

From the viewpoint of more effectively improving the balance of filling properties, fluidity, and ash uniformity during compression molding, the inorganic filler (C) preferably has R/R _max of 0.4 or more, more preferably greater than 0.50, and 0.52 The above is particularly preferable. Moreover, from a viewpoint of improving the fillability at the time of compression molding, it is preferable that the inorganic filler (C) satisfy _|fills the relationship of R<Rmax. In this case, R/R _max becomes less than 1.0.

In the volume-based particle size distribution of the entire inorganic filler (C), the frequency of particles having a mode diameter R is preferably 3.5% or more and 15% or less, more preferably 4% or more and 10% or less, 4.5% or more and 9% The following are especially preferable. Thereby, the ratio of the particle|grains which has the mode diameter R or the particle diameter close to the mode diameter R can be made high. For this reason, with respect to the mold underfill material for compression molding, the balance of fluidity|liquidity and filling property can be improved more effectively.

In addition, in the volume-based particle size distribution of the entire inorganic filler (C), the frequency of particles having a particle size of 0.8 × R or more and 1.2 × R or less is preferably 10% or more and 60% or less, and 12% or more and 50% or less It is more preferable, and it is especially preferable that it is 15 % or more and 45 % or less. Thereby, the ratio of the particle|grains which have the mode diameter R or the particle diameter close to the mode diameter R can be made high reliably. For this reason, with respect to the mold underfill material for compression molding, the balance of fluidity|liquidity and filling property can be improved more effectively.

Moreover, in the volume-based particle size distribution of the whole inorganic filler (C), it is preferable that the frequency of the particle|grains which have a particle size of 0.5xR or less is 5 % or more and 50 % or less. By setting the frequency of particles having a relatively small particle size with respect to the mode diameter R within the above range, it becomes possible to realize a mold underfill material for compression molding that is more excellent in fluidity.

In addition, the particle size distribution of an inorganic filler (C) can be adjusted by classifying raw material particles using a sieve, a cyclone (air classification), etc., for example. In addition, the measurement of the particle size distribution in the inorganic filler (C), such as particle diameter _Rmax and mode diameter R, can be performed using, for example, Shimadzu Corporation's laser diffraction scattering type particle size distribution meter SALD-7000. there is.

In the present embodiment, the content of the inorganic filler (C) in the mold underfill material for compression molding is preferably 50% by weight or more, more preferably 60% by weight or more, based on the entire mold underfill material for compression molding. By carrying out content of an inorganic filler (C) more than the said lower limit, low hygroscopicity and low thermal expansibility can be improved, and the moisture reliability and reflow property of a semiconductor package can be improved more effectively.

On the other hand, the content of the inorganic filler (C) in the mold underfill material for compression molding is preferably 93% by weight or less, more preferably 91% by weight or less, based on the entire mold underfill material for compression molding. By making content of an inorganic filler (C) or less into the said upper limit, it becomes possible to improve more effectively the fluidity|liquidity and filling property at the time of compression molding of the mold underfill material for compression molding.

((D) curing accelerator)

The mold underfill material for compression molding may further contain, for example, a curing accelerator (D). The curing accelerator (D) should just accelerate the crosslinking reaction between the epoxy group of the epoxy resin (A) and the curing agent (B) (for example, the phenolic hydroxyl group of the phenol resin curing agent), for example, a general epoxy resin for sealing What is used in the composition can be used. Examples of the curing accelerator (D) include phosphorus atom-containing compounds such as organic phosphine, tetrasubstituted phosphonium compound, phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound. ; 1,8-diazabicyclo(5,4,0)-undecene-7, benzyldimethylamine, 2-methylimidazole, etc. are exemplified amidine and tertiary amine, furthermore, 4 of the amidine and amine Nitrogen atom-containing compounds, such as a supply flame, etc. are mentioned, These may be used individually by 1 type, and may use 2 or more types together. Among these, it is more preferable to use a phosphorus atom containing compound from a viewpoint of improving sclerosis|hardenability. In addition, from the viewpoint of improving the balance between fluidity and curability, curing having latent properties such as a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound It is more preferable to use an accelerator. Moreover, it is especially preferable to use the adduct of a phosphine compound and a quinone compound, or the adduct of a phosphonium compound and a silane compound from a viewpoint of improving the filling property at the time of compression molding. Moreover, from a viewpoint of manufacturing cost, organic phosphine and a nitrogen atom containing compound can also be used suitably.

Examples of the organic phosphine used as the curing accelerator (D) include first phosphine such as ethylphosphine and phenylphosphine; second phosphine such as dimethylphosphine and diphenylphosphine; 3rd phosphine, such as a trimethyl phosphine, a triethyl phosphine, a tributyl phosphine, and a triphenyl phosphine, is mentioned.

As a tetra-substituted phosphonium compound used as a hardening accelerator (D), the compound represented, for example by following General formula (4) is mentioned.

[Formula 4]

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

Although the compound represented by General formula (4) is obtained as follows, for example, it is not limited to this. First, a tetra-substituted phosphonium halide, an aromatic organic acid, and a base are mixed in an organic solvent and uniformly mixed to generate an aromatic organic acid anion in the solution system. Then, when water is added, the compound represented by General formula (4) can be precipitated. In the compound represented by the general formula (4), R1, R2, R3 and R4 bonded to the phosphorus atom are phenyl groups, and AH is a hydroxyl group from the viewpoint of excellent balance between the acquisition rate and the curing promoting effect during synthesis. It is preferable that it is a compound which has in an aromatic ring, ie, a phenol compound, and that A is an anion of this phenol compound. In addition, the phenol compound refers to monocyclic phenol, cresol, catechol, resorcin, condensed polycyclic naphthol, dihydroxynaphthalene, (polycyclic) bisphenol A having a plurality of aromatic rings, bisphenol F, bisphenol S, bi A phenol, a phenylphenol, a phenol novolak, etc. are included in the concept, Among these, the phenol compound which has two hydroxyl groups is used preferably.

As a phosphobetaine compound used as a hardening accelerator (D), the compound etc. which are represented, for example by following General formula (5) are mentioned.

[Formula 5]

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

Although the compound represented by General formula (5) is not specifically limited, For example, a triaromatic-substituted phosphine which is a 3rd phosphine and a diazonium salt are made to contact, The diazonium group which a triaromatic-substituted phosphine and a diazonium salt have It can be obtained through the process of substituting.

As an adduct of the phosphine compound used as a hardening accelerator (D), and a quinone compound, the compound etc. which are represented, for example by following General formula (6) are mentioned.

[Formula 6]

(In the general formula (6), P represents a phosphorus atom, R5, R6 and R7 each independently represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, R8, R9 and R10 are, each independently represents 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)

Examples of the phosphine compound used for the adduct of the phosphine compound and the quinone compound include triphenylphosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, trinaphthylphosphine, tris(benzyl) It is preferable that unsubstituted or substituents, such as an alkyl group and an alkoxyl group, exist in aromatic rings, such as a phosphine, and what has C1-C6 as substituents, such as an alkyl group and an alkoxyl group, is mentioned. From the viewpoint of availability, triphenylphosphine is preferable.

Moreover, as a quinone compound used for the adduct of a phosphine compound and a quinone compound, o-benzoquinone, p-benzoquinone, and anthraquinones are mentioned, Among these, p-benzoquinone is preferable at the point of storage stability.

Although the adduct of a phosphine compound and a quinone compound is not specifically limited, For example, organic tertiary phosphine and benzoquinone can be obtained by making them contact and mix in the solvent in which both can be dissolved. The solvent is preferably a ketone such as acetone or methyl ethyl ketone, which has low solubility in adducts.

In the compound represented by the general formula (6), a compound wherein R5, R6 and R7 bonded to a phosphorus atom are a phenyl group, and R8, R9 and R10 are a hydrogen atom, that is, 1,4-benzoquinone and triphenylphosphine; The added compound is preferable from the viewpoint of lowering the thermal elastic modulus of the cured underfill material for compression molding.

As an adduct of a phosphonium compound and a silane compound used as a hardening accelerator (D), the compound etc. which are represented, for example by following formula (7) are mentioned.

[Formula 7]

(In the general formula (7), P represents a phosphorus atom and Si represents a silicon atom. R11, R12, R13 and R14 each independently represent an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group; , X2 is an organic group bonding to the groups Y2 and Y3. X3 is an organic group bonding to the groups Y4 and Y5. Y2 and Y3 represent a group formed by a proton-donating group releasing a proton, and a group in the same molecule Y2 and Y3 combine with a silicon atom to form a chelate structure, Y4 and Y5 represent a group formed by a proton-donating group releasing a proton, and groups Y4 and Y5 in the same molecule combine with a silicon atom to form a chelate structure X2 and X3 may be the same or different from each other, and Y2, Y3, Y4, and Y5 may be the same or different from each other. Z1 is an organic group having an aromatic or heterocyclic ring, or an aliphatic group)

In the general formula (7), as R11, R12, R13 and R14, for example, a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group, a naphthyl group, a hydroxynaphthyl group, a benzyl group, a methyl group, an ethyl group, n- A butyl group, n-octyl group, cyclohexyl group, etc. are mentioned, Among these, the aromatic group which has substituents, such as a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group, a hydroxynaphthyl group, or an unsubstituted aromatic group more preferably.

Moreover, in general formula (7), X2 is an organic group couple|bonded with Y2 and Y3. Similarly, X3 is an organic group bonded to the groups Y4 and Y5. Y2 and Y3 are groups formed by a proton-donating group releasing a proton, and the groups Y2 and Y3 in the same molecule combine with a silicon atom to form a chelate structure. Similarly, Y4 and Y5 are groups formed by a proton-donating group releasing a proton, and the groups Y4 and Y5 in the same molecule combine with a silicon atom to form a chelate structure. The groups X2 and X3 may be the same as or different from each other, and the groups Y2, Y3, Y4, and Y5 may be the same as or different from each other. The groups represented by -Y2-X2-Y3- and -Y4-X3-Y5- in the general formula (7) are constituted by a group in which a proton donor releases two protons. As the proton donor, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule is preferable, and an aromatic compound having at least two carboxyl groups or hydroxyl groups on carbon constituting the aromatic ring is further preferable, and further, an aromatic ring An aromatic compound having at least two hydroxyl groups on adjacent carbons to constitute is more preferable. For example, catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2'-biphenol, 1,1'-bi-2-naphthol, salicylic acid, 1 -Hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl alcohol, 1,2-cyclohexanediol, 1,2-propanediol and glycerin can be heard Among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferable from a viewpoint of the balance of the easiness of a raw material acquisition and a hardening acceleration|stimulation effect.

In addition, Z1 in the general formula (7) represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring, and specific examples thereof include aliphatic carbonization such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and an octyl group. Reactive substituents, such as aromatic hydrocarbon groups, such as a hydrogen group, a phenyl group, a benzyl group, a naphthyl group, and a biphenyl group, a glycidyloxypropyl group, a mercaptopropyl group, an aminopropyl group, and a vinyl group, etc. are mentioned. Among these, a methyl group, an ethyl group, a phenyl group, a naphthyl group, and a biphenyl group are more preferable from the point of thermal stability.

Although the manufacturing method of the adduct of a phosphonium compound and a silane compound is not specifically limited, For example, it can carry out as follows. First, a silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene are added to and dissolved in a flask containing methanol, and then, a sodium methoxide-methanol solution is added dropwise while stirring at room temperature. Furthermore, when a solution obtained by dissolving a previously prepared tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide in methanol is added dropwise thereto while stirring at room temperature, crystals are precipitated. When the precipitated crystals are filtered, washed with water and vacuum dried, an adduct of a phosphonium compound and a silane compound is obtained.

In the present embodiment, the content of the curing accelerator (D) in the mold underfill material for compression molding is preferably 0.05 wt% or more, more preferably 0.1 wt% or more, based on the total amount of the compression molding mold underfill material, It is especially preferable that it is 0.15 weight% or more. By making content of a hardening accelerator (D) more than the said lower limit, sclerosis|hardenability at the time of compression molding can be improved effectively.

On the other hand, the content of the curing accelerator (D) in the mold underfill material for compression molding is preferably 1% by weight or less, more preferably 0.5% by weight or less, based on the entire mold underfill material for compression molding. By carrying out content of a hardening accelerator (D) below the said upper limit, the improvement of the fluidity|liquidity at the time of compression molding can be aimed at.

((E) Coupling agent)

The mold underfill material for compression molding may further contain a coupling agent (E), for example. Examples of the coupling agent (E) include various silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, vinylsilane, and methacrylsilane, titanium-based compounds, aluminum chelates, and aluminum/zirconium. Well-known coupling agents, such as a system compound, can be used. Examples of these include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4). -Epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyl Methyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane , γ-anilinopropylmethyldimethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N- β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-( β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltri Ethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-mercaptopropylmethyldimethoxysilane, Silane-based coupling agents such as 3-isocyanate propyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and hydrolyzate of 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine , isopropyltriisostearoyltitanate, isopropyltris(dioctylpyrophosphate)titanate, isopropyltri(N-aminoethyl-aminoethyl)titanate, tetraoctylbis(ditridecylphosphite)titanate , tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxy acetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, Isopropyltrioctanoyltitanate, isopropyldimethacrylisostearoyltitanate, isopropyltridodecylbenzenesulfonyltitanate, isopropylisostearoyldiacryl titanate, isopropylt and titanate-based coupling agents such as li(dioctylphosphate)titanate, isopropyltricumylphenyltitanate, and tetraisopropylbis(dioctylphosphite)titanate. These may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, the silane compound of epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, or vinylsilane is more preferable. Moreover, from a viewpoint of improving fillability and moldability more effectively, it is especially preferable to use the secondary aminosilane typified by N-phenyl-γ-aminopropyltrimethoxysilane.

In the present embodiment, the content of the coupling agent (E) in the mold underfill material for compression molding is preferably 0.1 wt% or more, and more preferably 0.15 wt% or more, based on the entire mold underfill material for compression molding. By making content of a coupling agent (E) more than the said lower limit, the dispersibility of an inorganic filler (C) can be made favorable.

On the other hand, it is preferable that it is 1 weight% or less with respect to the whole mold underfill material for compression molding, and, as for content of the coupling agent (E) in the mold underfill material for compression molding, it is more preferable that it is 0.5 weight% or less. By carrying out content of a coupling agent (E) below the said upper limit, the fluidity|liquidity at the time of compression molding can be improved, and the improvement of fillability and moldability can be aimed at.

The mold underfill material for compression molding may further include, if necessary, an ion scavenger such as hydrotalcite; colorants such as carbon black and bengala; low-stress components such as silicone rubber; natural waxes such as carnauba wax, synthetic waxes such as montanic acid ester wax, higher fatty acids such as zinc stearate and metal salts thereof, or mold release agents such as paraffin; flame retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphagen; Various additives, such as antioxidant, may be mix|blended suitably.

The mold underfill material for compression molding in the present embodiment can be made into powder or granular material by mixing and kneading the above components, and then using various methods such as pulverization, granulation, extrusion cutting and sieving alone or in combination. there is. As a method of obtaining a powder or granular material, for example, each raw material component is premixed with a mixer, and this is heated and kneaded with a kneader such as a roll, a kneader or an extruder, and then a cylindrical outer peripheral portion having a plurality of small holes and a disk-shaped bottom surface. A method of supplying a melt-kneaded resin composition to the inside of a rotor consisting of, and passing the resin composition through a small hole by centrifugal force obtained by rotating the rotor (centrifugal milling method); A method of obtaining a pulverized product by kneading in the same manner as described above, followed by cooling and pulverization steps, and then granulating and removing fine powder using a sieve (pulverization and sieving method); After each raw material component is premixed with a mixer, heat-kneading is performed using an extruder provided with a die having a plurality of small diameters arranged at the tip of the screw, and the molten resin is extruded in a strand form from a small hole arranged in the die. A method of obtaining by cutting with a cutter that slides and rotates substantially parallel to the die surface (hereinafter also referred to as "hot-cut method"), etc. are mentioned. In either method, by selecting kneading conditions, centrifugal conditions, sieving conditions, cutting conditions, and the like, it is possible to obtain a mold underfill material for compression molding having a desired particle size distribution.

Next, the semiconductor package 100 which concerns on this embodiment is demonstrated.

1 is a cross-sectional view showing a semiconductor package 100 according to 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, the case where the semiconductor element 20 is flip-chip mounted on the board|substrate 10 via the bump 22 is illustrated. The sealing material 30 encapsulates the semiconductor element 20 , and is also filled in the gap 24 between the substrate 10 and the semiconductor element 20 . The sealing material 30 is obtained by shape|molding the above-mentioned mold underfill material for compression molding using the compression molding method. In this case, it is possible to fill the gap 24 while sealing the semiconductor element 20 by using a mold underfill material for compression molding excellent in filling properties, so that it is possible to realize the semiconductor package 100 having excellent reliability. do.

The semiconductor package 100 is manufactured as follows, for example. First, the semiconductor device 20 is disposed on the substrate 10 with bumps 22 interposed therebetween. Next, using the compression molding method, the semiconductor element 20 is sealed with the mold underfill material for compression molding according to the present embodiment described above, and the gap 24 between the substrate 10 and the semiconductor element 20 . ) is charged. Accordingly, the encapsulant 30 is formed. The compression molding method can be performed, for example, using a compression molding machine under the conditions of 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.

Next, the structure 102 according to the present embodiment will be described.

2 is a cross-sectional view showing the structure 102 according to the present embodiment. The structure 102 is a molded article formed by MAP molding. For this reason, by dividing the structure 102 into individual pieces for each semiconductor element, a some semiconductor package is obtained.

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 arranged on the substrate 10 . In FIG. 2, the case where each semiconductor element 20 is flip-chip mounted on the board|substrate 10 via the bump 22 is illustrated. The sealing material 30 seals the some semiconductor element 20, and the clearance gap 24 between the board|substrate 10 and each semiconductor element 20 is filled. The sealing material 30 is obtained by shape|molding the above-mentioned mold underfill material for compression molding using the compression molding method. In this case, the inside of each gap|interval 24 can be filled, sealing each semiconductor element 20 using the mold underfill material for compression molding excellent in filling property.

The structure 102 is manufactured as follows, for example. First, a plurality of semiconductor devices 20 are disposed on a substrate 10 . Each semiconductor element 20 is mounted on the board|substrate 10 via the bump 22, for example. Next, using the compression molding method, while sealing the some semiconductor element 20 with the mold underfill material for compression molding which concerns on this embodiment mentioned above, between the board|substrate 10 and each semiconductor element 20 fill the gap (24) of Accordingly, the encapsulant 30 is formed. The compression molding method can be performed, for example, using a compression molding machine under the conditions of 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.

Example

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

(Preparation of mold underfill material)

First, each raw material blended according to Table 1 was kneaded at 110°C for 7 minutes using a twin-screw kneading extruder. Next, after performing deaeration and cooling, the obtained kneaded material was grind|pulverized with a grinder, and the powder and granular material were obtained. In Examples 1 to 7 and Comparative Examples 1 to 3, the obtained powder or granular material was further sieved to obtain a mold underfill material for compression molding. Moreover, in Comparative Example 4, the tablet-shaped mold underfill material for transfer molding was obtained by tableting the said material grind|pulverized to the extent that tablet tableting was possible. The detail of each component in Table 1 is as follows. In addition, the unit in Table 1 is weight%.

(A) Epoxy resin

Epoxy resin 1: phenol aralkyl type epoxy resin having a biphenylene skeleton (Nippon Kayaku Co., Ltd. product, NC-3000)

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

(B) curing agent

Curing agent 1: phenol aralkyl resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., GPH-65)

Hardener 2: Triphenolmethane type phenol resin (Meiwa Kasei Co., Ltd. product, MEH-7500)

(C) inorganic fillers

Silica 1: Fused spherical silica (mode diameter R=10 μm, particle size R _max =18 μm, R/R _max =0.56)

Silica 2: Fused spherical silica (mode diameter R=5 μm, particle size R _max =10 μm, R/R _max =0.5)

Silica 3: Fused spherical silica (mode diameter R = 10 μm, particle diameter R _max = 24 μm, R/R _max =0.42)

(D) curing accelerator

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

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

Curing accelerator 3: triphenylphosphine

[Formula 8]

[Formula 9]

(E) coupling agent

Coupling agent 1: γ-glycidoxypropyltrimethoxysilane (GPS-M manufactured by Chiso Corporation)

Coupling agent 2: N-phenyl-γ-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-573)

(F) other ingredients

Ion scavenger: hydrotalcite (manufactured by Kyowa Chemical Industries, Ltd., DHT-4H)

Release agent: Montan acid ester wax (Clariant Japan Co., Ltd., WE-4M)

Flame retardant: aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., CL-303)

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

(measurement of time T(5))

For each of Examples 1 to 7 and Comparative Examples 1 to 4, the curing torque of the mold underfill material was measured at a mold temperature of 175° C. using a curing meter (manufactured by Orientec Co., Ltd., JSR curing meter IVPS type). measured over time. Based on the measurement result, the time T(5) from the start of the measurement to reaching 5% of the torque (defined as the maximum torque) in 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, using a solidified flow tester (manufactured by Shimadzu Corporation, CFT-500C), the temperature was 175° C. and the load was 40 kgf (piston area 1 cm ² ) , the apparent viscosity η of the melted mold underfill material under the test conditions of a die hole diameter of 0.50 mm and a die length of 1.00 mm was measured. The viscosity η was calculated from the following formula. In the formula, Q is the flow rate of the mold underfill material flowing per unit time. The unit in Table 1 is Pa·second.

η=(4πDP/128LQ)×10 ^-3 (Pa sec)

η: apparent viscosity

D: Die hole diameter (mm)

P: test pressure (Pa)

L: die length (mm)

Q: Flow rate (cm ³ /sec)

(fillability)

About each Example and each comparative example, the filling property was evaluated as follows.

In Examples 1 to 7 and Comparative Examples 1 to 3, flip chip MAP (Mold Array Package) BGA (185 × 65 mm × 0.36 mmt bismaleimide triazine resin/glass cloth substrate, 10 × 10 mm × 200 μmt chip 3 × 10 pcs., mold resin 180 × 60 mm × 450 μmt, the gap between the substrate and the chip is 70 μm, 30 μm used, the bump spacing is 200 μm), a compression molding machine (manufactured by TOWA Co., Ltd., PMC1040) was used, and sealing was carried out with a mold underfill material for compression molding under the conditions of a mold temperature of 175°C, a molding pressure of 3.9 MPa, and a curing time of 90 seconds.

In Comparative Example 4, the flip-chip MAPBGA was applied to a transfer molding mold underfill material using a transfer molding machine (manufactured by Towa Co., Ltd., Y series) at a mold temperature of 175° C., an injection pressure of 6.9 MPa, and a curing time of 90 seconds. molded by

Next, the filling property of the mold underfill material in the clearance gap between the board|substrate and a chip|tip after shaping|molding was observed using the ultrasonic flaw detector (Hitachi Genki Co., Ltd. product, FS300). In Table 1, when the mold underfill material was filled with no gap between the substrate and the chip, it was evaluated as ○, and when it was detected that there was no filling between the substrate and the chip, it was evaluated as x. In addition, when blisters were observed on the package surface due to poor curing, it was described as impossible to mold. Table 1 shows the results when the gap between the substrate and the chip was 70 µm and the gap between the substrate and the chip was 30 µm.

(ash uniformity)

About each Example and each comparative example, the ash content uniformity was evaluated as follows.

First, a flip-chip MAPBGA was prepared in the same manner as in the evaluation of the fillability, except that the substrate was changed to a metal plate of the same size and a mold release agent was thinly applied to the surface of the metal plate. Next, using the molding machine similar to the said fillability evaluation, the flip-chip type MAPBGA was encapsulated and molded using the mold underfill material under the same conditions.

Next, the resin parts on the two long sides of the obtained molded article were cut out from the outer edge by 5 mm, the members other than the resin were removed, and freeze-grinding was performed, respectively, to obtain two samples corresponding to the two long sides, respectively. Next, about each sample, it heated up to 500 degreeC at the temperature increase rate of 30 degreeC/min using the differential thermal balance, it held for 30 minutes, and the weight of the residue was measured. This measurement was repeated 3 times. Next, for each sample, the value obtained by dividing the weight of the residue after three measurements by the original weight was taken as the ash content (% by weight). And the ash content uniformity was evaluated according to the value which divided the ash content of one sample with a small ash content by the ash content of the other sample with a large ash content. A result is shown in Table 1.

[Table 1]

In Examples 1-7, the filling property was favorable in all. Among these, Examples 1-5 showed more excellent ash uniformity compared with Examples 6 and 7. On the other hand, in Comparative Examples 1 and 2, the filling properties under the chip during MAP molding by the compression molding method were not sufficient. In Comparative Example 3, the curability of the mold underfill material in the large-area MAP molded article was not sufficient, and blisters occurred. In Comparative Example 4 in which MAP molding was performed by transfer molding, it was found that the filling property under the chip, which is a narrow gap, was not sufficient. Moreover, in the comparative example 4, the ash uniformity in MAP shaping|molding of a large area was less than 0.9, and it turned out that sufficient ash uniformity was not obtained. It was found that the present invention exhibits remarkable effects in MAP molding for molding a large area and in molding underfill type, particularly in fillability and ash uniformity under the chip, which is a narrow gap, compared to conventional transfer molding.

Claims (10)

A mold underfill material for compression molding that encapsulates a semiconductor element disposed on a substrate and fills a gap between the substrate and the semiconductor element,
an epoxy resin (A);
a curing agent (B);
an inorganic filler (C);
a curing accelerator (D);
a coupling agent (E);
The curing accelerator (D) contains at least one of a phosphobetaine compound and an adduct of a phosphonium compound and a silane compound,
The coupling agent (E) comprises an aminosilane,
In the inorganic filler (C), when the particle size at which the cumulative frequency becomes 5% when viewed from the maximum particle size side of the volume-based particle size distribution is R _max , and the particle size corresponding to the maximum peak of the volume-based particle size distribution is the mode diameter R , R/R _max > 0.50,
It is a granular,
A mold underfill material for compression molding whose time T(5) from the start of measurement to reaching 5% of the maximum torque is 25 seconds or more and 100 seconds or less when measured using a curastometer under the conditions of a mold temperature of 175°C . The method according to claim 1,
The mold underfill material for compression molding whose viscosity η at 175°C measured using a solidification flow tester is 3.5 Pa·sec or more and 15 Pa·sec or less. 3. The method according to claim 2,
The mold underfill material for compression molding whose time T(5)/viscosity (eta) is 2 Pa ^-1 or more and 30 Pa ^-1 or less. delete delete The method according to claim 1 or 2,
The epoxy resin (A) contains a biphenyl-type epoxy resin,
The mold underfill material for compression molding in which the said hardening|curing agent (B) contains a phenol resin type hardening|curing agent. The method according to claim 1 or 2,
The said inorganic filler (C) is a silica mold underfill material for compression molding. The semiconductor package obtained by sealing the semiconductor element arrange|positioned on a board|substrate using the mold underfill material for compression molding of Claim 1 or 2, and filling the clearance gap between the said board|substrate and the said semiconductor element. A structure obtained by sealing a plurality of semiconductor elements disposed on a substrate using the mold underfill material for compression molding according to claim 1 or 2 and filling a gap between the substrate and each of the semiconductor elements. A step of arranging a semiconductor element on a substrate with bumps interposed therebetween;
A step of sealing the semiconductor element with the compression molding mold underfill material according to any one of claims 1 to 3 using a compression molding method and filling a gap between the substrate and the semiconductor element. A method for manufacturing a semiconductor package.

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