JP2001118969A - Molding material for sealing, its manufacturing method, and electronic part device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding material for sealing which is high in adhesion to an insert and excellent in reflow cracking resistance, moisture resistance, and reliability, easily packed for shipping, and easily controlled in moisture absorption, in a process where an electronic device such as a semiconductor device is manufactured, a method of manufacturing the same, and an electronic part device equipped with an element sealed up with the same. SOLUTION: A molding material for sealing is composed of integral components such as an epoxy resin, a hardening agent, and a filler. All the components are heated, kneaded, then cooled down, and subjected to aging and/or heating/kneading for the formation of a molding material for sealing. A method of manufacturing the molding material for sealing and an electronic part device equipped with an element sealed up with the above molding material for sealing are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a molding compound for sealing,
The present invention relates to a manufacturing method thereof and an electronic component device including an element sealed with a sealing molding material.

[0002]

2. Description of the Related Art In recent years, high-density mounting of electronic component elements has been advanced. Along with this trend, electronic component devices have become mainstream from conventional pin insertion type packages to surface mount type packages. Surface mount type ICs, LSIs, etc. are thin and small packages in order to increase the packaging density and reduce the mounting height, so that the area occupied by the elements in the package increases, and the thickness of the package becomes extremely large. It is getting thinner. Further, these packages are different in mounting method from the conventional pin insertion type. That is, in the pin insertion type package, the pins are inserted into the wiring board and then soldered from the back surface of the wiring board, so that the package is not directly exposed to a high temperature. However, since the surface mount IC is temporarily fixed to the surface of the wiring board and processed by a solder bath or a reflow device, it is directly exposed to a soldering temperature (reflow temperature). As a result, when the IC package absorbs moisture, that is, when the molding material for sealing contains water, the absorbed moisture evaporates during reflow, and the generated vapor pressure acts as a peeling stress, and inserts such as elements and lead frames. Peeling occurs between the product and the molding compound for sealing, which causes package cracks and poor soldering. At present, this phenomenon is a major problem relating to surface mount type electronic component devices. 2. Description of the Related Art Conventionally, in the field of element sealing of electronic component devices such as transistors and ICs, resin sealing has been the mainstream in terms of productivity, cost, and the like, and epoxy resin molding materials have been widely used as sealing molding materials. This is because
This is because the epoxy resin is well balanced in various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to an insert product.

[0003]

However, a sealing molding material produced by a general method of heating and kneading components such as an epoxy resin, a curing agent, and a filler has insufficient adhesion to an insert product. However, the above problems have not been solved. Therefore, in electronic component devices sealed with the current sealing molding material, measures such as moisture-proof packing and shipping, or sufficient drying before use before mounting on a wiring board are taken. However, these methods are troublesome and costly. The present invention has been made in view of such a situation, and has high adhesiveness to an insert product, excellent reflow crack resistance, excellent reliability such as moisture resistance, packing at the time of shipment, and electronic component devices such as semiconductor devices. An object of the present invention is to provide an epoxy resin molding material for encapsulation, a method for producing the same, and an electronic component device equipped with an element encapsulated with the encapsulating molding material, which also facilitates the management of moisture absorption in the production process.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, kneaded components such as an epoxy resin, a curing agent, and a filler, and then cooled them.
Furthermore, it has been found that the above object can be achieved by a sealing molding material produced by a method of performing aging treatment and / or heat kneading, and the present invention has been completed.

[0005] That is, the present invention provides (1) a sealing composition comprising essential components of an epoxy resin, a curing agent, and a filler, followed by heating, kneading and cooling all the components, followed by aging treatment and / or heat kneading. (1) The molding material according to the above (1), wherein the molding material and (2) a compounding component having an epoxy resin, a curing agent, and a filler as essential components are heated and kneaded, then cooled, and further subjected to an aging treatment and / or a heat kneading. The present invention relates to a method for producing a molding material for sealing, and (3) an electronic component device including an element sealed with the molding material for sealing described in (1) above.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The molding material for sealing of the present invention contains an epoxy resin, a curing agent and a filler as essential components.

[0007] The epoxy resin used in the present invention is generally used for molding materials for encapsulation and is not particularly limited. For example, phenols such as phenol novolak epoxy resins and orthocresol novolak epoxy resins , Cresol, xylenol,
Phenols such as resorcin, catechol, bisphenol A, bisphenol F and / or α-naphthol;
Epoxidized novolak resin obtained by condensing or co-condensing naphthols such as β-naphthol and dihydroxynaphthalene with compounds having an aldehyde group such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde under an acidic catalyst. Diglycidyl ethers such as bisphenol A, bisphenol F, bisphenol S, alkyl-substituted or unsubstituted biphenol, stilbene-type diglycidyl ether, phenol aralkyl resin, naphthol
Epoxidized aralkyl resins, epoxidized adducts or polyadducts of phenols with dicyclopentadiene or terpenes, glycidyl esters obtained by the reaction of epichlorohydrin with polybasic acids such as phthalic acid and dimer acid -Type epoxy resin, glycidylamine-type epoxy resin obtained by reaction of polyamine such as diaminodiphenylmethane, isocyanuric acid and epichlorohydrin, trimethylolpropane-type epoxy resin, epoxy resin having naphthalene ring, olefin bond is oxidized with peracid such as peracetic acid Examples thereof include a linear aliphatic epoxy resin, an alicyclic epoxy resin, and the like, which may be used alone or in combination of two or more.
Among them, from the viewpoint of reflow crack resistance, 4,4′-
Bis (2,3-epoxypropoxy) -3,3 ', 5
5′-tetramethylbiphenyl, 4,4′-bis (2,
A biphenyl-type epoxy resin containing 3-epoxypropoxy) biphenyl or the like as a main component is preferable. When this biphenyl-type epoxy resin is used, its blending amount is preferably at least 60% by weight based on the total amount of the epoxy resin.
If the content is less than 60% by weight, the epoxy resin is less likely to exhibit low moisture absorption and high adhesiveness, and the effect on reflow crack resistance tends to be small.

[0008] The curing agent used in the present invention is not particularly limited, and is generally used in resin molding materials for sealing. Examples thereof include phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, and phenylphenol. And phenols such as aminophenol and / or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene and a compound having an aldehyde group such as formaldehyde in the presence of an acidic catalyst in the form of a resin or phenol. Aralkyl resins, naphthol aralkyl resins, etc. synthesized from phenols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl. These may be used alone or in combination of two or more. Is also good. Among them, from the viewpoint of reflow crack resistance, phenol-aralkyl resin is preferable,
Specific examples include p-xylylene-type ziloc, m-xylylene-type ziloc, and the like. When this phenol / aralkyl resin is used, its blending amount is preferably 60% by weight or more based on the total amount of the curing agent in order to exhibit its performance.

The equivalent ratio of the epoxy resin to the curing agent, that is, the ratio of the number of epoxy groups in the epoxy resin / the number of hydroxyl groups in the curing agent is not particularly limited, but is preferably set at 0. It is preferably set in the range of 5 to 2, more preferably 0.7 to 1.3. In order to obtain a molding compound for sealing having excellent reflow crack resistance, it is more preferable to set this ratio in the range of 0.8 to 1.2.

The filler used in the present invention is blended in a molding compound for sealing in order to reduce the hygroscopicity, the coefficient of linear expansion, improve the thermal conductivity and improve the strength, and an inorganic filler is preferred. Examples of the inorganic filler include fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, and steer. Examples include powders of tight, spinel, mullite, titania, etc., or spherical beads or glass fibers thereof. Further, as the inorganic filler having a flame retardant effect, aluminum hydroxide,
Examples include magnesium hydroxide, zinc borate, zinc molybdate and the like. These fillers may be used alone or in combination of two or more. Among the above fillers,
Fused silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferred from the viewpoint of high thermal conductivity, and the particle shape of the filler is preferably spherical from the viewpoint of fluidity during molding and mold wear. From the viewpoint of flame retardancy, reflow crack resistance, moldability, hygroscopicity, reduction of linear expansion coefficient and improvement of strength, the amount of the filler is 70% by weight based on the entire molding material for sealing.
From the viewpoint of reflow crack resistance and fluidity, the range is more preferably from 80 to 95% by weight, and 88 is preferable.
~ 92% by weight is more preferred.

The sealing molding material of the present invention may contain a curing accelerator, if necessary. The curing accelerator is generally used in molding materials for sealing and is not particularly limited. Examples thereof include 1,8-diaza-bicyclo [5.4.0] undecene-7,1,5-diaza. -Bicyclo [4.3.0] nonene-5,6-dibutylamino-
1,8-diaza-bicyclo [5.4.0] undecene-
7,6-n-hexyl-1,8-diazabicyclo [5.
4.0] Cycloamidine compounds such as undecene-7 and the like, and maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone,
Quinones such as 3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone and phenyl-1,4-benzoquinone Compound, diazophenylmethane, a compound having an intramolecular polarization obtained by adding a compound having a π bond such as a phenol resin, benzyldimethylamine, triethanolamine,
Tertiary amines such as dimethylaminoethanol and tris (dimethylaminomethyl) phenol and derivatives thereof, imidazoles such as 2-methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole and derivatives thereof, tributyl Phosphine,
Dibutylphenylphosphine, butyldiphenylphosphine, ethyldiphenylphosphine, methyldiphenylphosphine, triphenylphosphine, tris (4-methylphenyl) phosphine, tris (4-methoxyphenyl) phosphine, tris (2,6-dimethoxyphenyl) phosphine, diphenyl Phosphine, organic phosphines such as phenylphosphine and phosphorus compounds having intramolecular polarization obtained by adding a compound having a π bond such as maleic anhydride, the above quinone compound, diazophenylmethane, and phenol resin to these organic phosphines, Tetraphenylphosphonium tetraphenylborate, triphenylphosphinetetraphenylborate, 2-ethyl-
4-methylimidazole tetraphenyl borate, N-
Examples include tetraphenylboron salts such as methylmorpholine tetraphenylborate and derivatives thereof. Among them, from the viewpoint of moldability, organic phosphines, cycloamidine compounds, or adducts thereof with quinone compounds are preferable, and triphenylphosphine is preferred. And adducts of tertiary phosphines such as tris (4-methylphenyl) phosphine and tris (4-methoxyphenyl) phosphine with quinone compounds such as p-benzoquinone and 1,4-naphthoquinone. These curing accelerators may be used alone or in combination of two or more. The amount of the curing accelerator is not particularly limited as long as the curing acceleration effect is achieved, but is preferably 0.005 to 2% by weight, more preferably 0.005 to 2% by weight, based on the entire molding material for sealing. 0.
The content is from 01 to 1% by weight, more preferably from 0.05 to 0.5% by weight. If it is less than 0.005% by weight, the curability in a short time tends to be inferior. If it exceeds 2% by weight, the curing rate tends to be too fast to obtain a good molded product.

[0012] The sealing molding material of the present invention may contain a conventionally known flame retardant, if necessary. For example,
Red phosphorus, phosphate ester, melamine, melamine derivative, compound having a triazine ring, nitrogen-containing compound such as cyanuric acid derivative, isocyanuric acid derivative, phosphorus / nitrogen-containing compound such as cyclophosphazene, zinc oxide, iron oxide, molybdenum oxide; Examples thereof include metal compounds such as ferrocene, antimony oxide, and brominated resins. These may be used alone or in combination of two or more.

Further, the molding material for sealing of the present invention includes an IC
For example, an anion exchanger may be blended from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of the semiconductor element. The anion exchanger is not particularly limited, and conventionally known ones can be used. Examples thereof include hydrotalcites, and hydrated oxides of elements selected from magnesium, aluminum, titanium, zirconium, and bismuth. These can be used alone or in combination of two or more.

Further, in the molding material for sealing of the present invention, higher fatty acids, metal salts of higher fatty acids,
Release agents such as ester wax, polyolefin wax, polyethylene, polyethylene oxide, dyes, coloring agents such as carbon black, epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane,
Coupling agents such as organic titanates and aluminum alcoholates, and stress relaxation agents such as silicone oil and silicone rubber powder can be blended as required.

[0015] The above-mentioned various components are weighed to a predetermined compounding amount, and first sufficiently mixed by a mixer or the like.
Mixing roll, extruder, heat kneading using a general method of kneading with a mill, etc., after cooling the resulting kneaded material, pulverized as necessary for easy use,
Thereafter, the molding material for sealing of the present invention can be produced by further performing aging treatment and / or heat kneading by the same general method as described above. After production, it is easy to use if it is cooled and pulverized as required, and tableted with dimensions and weights that match the molding conditions. The aging treatment and the heating and kneading may be performed either or only one of them. Here, the aging treatment refers to leaving the molding compound for sealing until the spiral flow is reduced by 5 to 30%, preferably 10 to 20%. As the leaving condition, the temperature is preferably 15 to 80. C., more preferably 25 to 60 C., and the time is preferably 1 to 48 hours, more preferably 6 to 24 hours. The various components of the molding compound for sealing may all be added at the same time, but the order of addition may be appropriately set. In addition, if necessary, various components can be pre-kneaded. For example, an epoxy resin and a curing agent, a curing agent and a curing accelerator, an epoxy resin and / or a curing agent and a release agent,
An epoxy resin and / or a curing agent and a stress relaxing agent, a filler and a coupling agent, and the like may be pre-kneaded at room temperature or under heating before use.

The electronic component device obtained by sealing the element with the sealing molding material obtained by the present invention includes a lead frame, a wired tape carrier, a wiring board, glass,
Active elements such as semiconductor chips, transistors, diodes, thyristors, etc., passive elements such as capacitors, resistors, resistor arrays, coils, switches, etc. are mounted on a support member such as a silicon wafer. An electronic component device obtained by sealing with a molding material for sealing may be used. As such an electronic component device, for example, a semiconductor element is fixed on a lead frame, and a terminal portion of an element such as a bonding pad and a lead portion are connected by wire bonding or a bump. DIP (Du) sealed by transfer molding using
al Inline Package), PLCC (Plastic Leaded Chip)
Carrier), QFP (Quad Flat Package), SOP (Sm
all Outline Package), SOJ (Small Outline J-lea
dpackage), TSOP (Thin Small Outline Packag)
e), a general resin-encapsulated IC such as TQFP (Thin QuadFlat Package), and a TC in which a semiconductor chip connected to a tape carrier by a bump is sealed with the molding material of the present invention.
P (Tape Carrier Package), active elements such as semiconductor chips, transistors, diodes, thyristors and / or capacitors, resistors, etc., connected to wires formed on wiring boards or glass by wire bonding, flip chip bonding, soldering, etc. A COB (Chip On Boad) module, a hybrid IC, a multi-chip module in which a passive element such as a coil is sealed with the sealing molding material of the present invention, and an organic substrate having a wiring board connection terminal formed on the back surface. After mounting the element and connecting the element and the wiring formed on the organic substrate by bump or wire bonding, BGA (Ball G) in which the element is sealed with the molding material for sealing of the present invention.
rid Array), CSP (Chip Size Package) and the like. Further, the epoxy resin molding material for encapsulation of the present invention can be effectively used for a printed circuit board.

As a method for sealing an element by using the molding material for sealing of the present invention, a low pressure transfer molding method is most common, but an injection molding method, a compression molding method or the like may be used.

In the molding material for sealing of the present invention, the various components are heated and kneaded, then cooled, subjected to an aging treatment and / or
Alternatively, it is considered that the affinity between the resin component and the filler is improved by heating and kneading, and as a result, the adhesion between the insert product and the molding material for sealing is improved.

[0019]

Next, the present invention will be described with reference to examples, but the scope of the present invention is not limited to these examples.

Examples 1 to 6 and Comparative Examples 1 to 3 Biphenyl type epoxy resin (Epicoat YX-400 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the epoxy resin.
0H), cresol novolak type epoxy epoxy resin (trade name ESCN195, manufactured by Sumitomo Chemical Co., Ltd.) and brominated epoxy resin (trade name BRE, manufactured by Nippon Kayaku Co., Ltd.)
NS), phenol aralkyl resin (Mirex XL225, manufactured by Mitsui Toatsu Chemicals, Inc.) as a curing agent
-3L) and a phenol novolak resin (trade name H-1 manufactured by Meiwa Kasei Co., Ltd.), triphenylphosphine as a curing accelerator, spherical fused silica having an average particle size of 17.5 μm and a specific surface area of 3.8 m ² / g as a filler. And carnauba wax (manufactured by Clariant) and carbon black (manufactured by Mitsubishi Chemical Corporation under the trade name MA-10) as other additives.
0), antimony trioxide, and γ-glycidoxypropyltrimethoxysilane (epoxysilane coupling agent) were respectively blended in the composition shown in Table 1, and preliminarily mixed by dry blending. The mixture was kneaded with a twin-screw roll (heat kneading) under the conditions of minutes, and cooled and pulverized.
Thereafter, kneading (heating and kneading) with a twin-screw roll is further performed under the same conditions as described above, and the mixture is cooled and pulverized. The sealing molding materials of Examples 4 to 6 and the sealing molding materials of Comparative Examples 1 to 3 were produced without any treatment.

[0021]

[Table 1]

The encapsulating molding materials of Examples and Comparative Examples were evaluated by the following tests. Table 2 shows the evaluation results. (1) Spiral flow Using a mold for spiral flow measurement according to EMMI-1-66, molding was performed under the conditions of 180 ° C., 90 seconds, and 7 MPa, and the flow distance (inch) was determined. (2) Al peel strength (index of adhesiveness) A test piece of 100 mm × 70 mm × 3 mm was formed on a 30 μm thick aluminum foil using an aluminum peel test mold.
Transfer molding was performed at 0 ° C. for 90 seconds at 7 MPa, and a 10-mm-wide aluminum foil was peeled off vertically using Tensilon at a head speed of 50 mm / min, and its strength was measured. did. After the transfer molding, post-curing was performed at 175 ° C. for 5 hours, and the post-curing strength was measured in the same manner. (3) Adhesion External dimensions 20 with 8 × 10 mm silicone chip mounted
A 54 pin package (QFP, 42 alloy lead frame) of 14 mm × 2 mm is transfer-molded under the conditions of 180 ° C., 90 seconds, 7 MPa, and the ultrasonic short wound device AT55 is used.
Using 00 (trade name, manufactured by Hitachi Construction Machinery Co., Ltd.), the presence or absence of peeling between the molding material for sealing and the insert product was observed, and the adhesion was evaluated. (4) Reflow crack resistance The package after the evaluation of adhesion in (3) above is baked at 125 ° C. for 24 hours, humidified at 85 ° C./85% RH for 50 hours, and then heated at 215 ° C./90 seconds. The reflow treatment was performed under the conditions, the presence or absence of cracks was observed, and evaluation was made based on the number of defective packages / the number of measurement packages. (5) Moisture resistance Aluminum wiring with a line width of 15 μm and a gap of 5 μm was provided7.
6.3 × 19.5 × 3.8 mm 16-pin package with a 2 × 3.9 mm silicone chip (D
IP, 42 alloy lead frame, no passivation) was prepared by transfer molding
After baking for 4 hours and humidifying for 72 hours under the condition of 85 ° C./85% RH, a treatment at 215 ° C./90 seconds is performed.
A disconnection failure due to aluminum wiring corrosion when left under the conditions of PCT2atm was examined by a conduction test, and the time during which the failure occurred in 50% of the measurement packages was counted.

[0023]

[Table 2]

In Comparative Examples 1 to 3, which were prepared by a general method of heating and kneading various components, the adhesiveness was low, and
Peeling from the insert product was observed. Further, the reflow crack resistance was not excellent and the moisture resistance was poor. On the other hand, in Examples 1 to 6 of the present invention, which were produced by performing aging treatment or heat kneading after cooling after heating and kneading,
The adhesiveness and the adhesion to the insert product were high, and the reflow crack resistance and moisture resistance were remarkably excellent.

[0025]

The molding material for sealing according to the present invention has high adhesion to the insert product, excellent reflow crack resistance and excellent moisture resistance reliability as shown in the examples, and its packaging at the time of shipment. In addition, the management of moisture absorption and the like in the manufacturing process of electronic component devices such as semiconductor devices is simplified.
Since an electronic component device having excellent reliability can be obtained by encapsulating elements such as C and LSI, its industrial value is great.

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Claims (3)

[Claims] An encapsulating molding material comprising an epoxy resin, a curing agent and a filler as essential components, all components being heated and kneaded, then cooled, subjected to an aging treatment and / or heated and kneaded. 2. The encapsulating material according to claim 1, wherein a compounded component comprising an epoxy resin, a curing agent and a filler as essential components is heated and kneaded, then cooled, and further subjected to an aging treatment and / or heat kneading. Manufacturing method of molding material. 3. An electronic component device comprising an element sealed with the molding material for sealing according to claim 1.