JP2020136450A - Sealant, semiconductor device sealed by the same, and method for manufacturing semiconductor package with the sealant - Google Patents

Abstract

To provide: a sealant for collectively sealing a semiconductor element-mount face and/or a semiconductor element-formed face, which can achieve a low warp; a semiconductor device arranged by use of the sealant; and a method for manufacturing a semiconductor package.SOLUTION: A sealant comprises an uncured resin layer on a one face of a resin-impregnated fiber base layer. The resin-impregnated fiber base layer is arranged by impregnating a cyclic imide compound-containing thermosetting resin composition (X) with a fiber base, and half- or full-curing the resultant resin composition. The uncured resin layer is formed from a cyclic imide compound-containing thermosetting resin composition (Y). The cyclic imide compounds included in the thermosetting resin composition (X) and the thermosetting resin composition (Y) are each a cyclic imide compound containing, in a molecule, at least one dimer acid skeleton, at least one straight-chain alkylene group with 6 or more carbon atoms and at least two cyclic imide groups.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sealing material, a semiconductor device sealed by the sealing material, and a method for manufacturing a semiconductor package having the sealing material.

Conventionally, various methods have been proposed and studied for wafer-level sealing of the semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or the semiconductor element forming surface of a wafer on which a semiconductor element is formed, and sealing by spin coating. Examples thereof include stopping, sealing by screen printing, and a method using a composite sheet in which a film support is coated with a heat-meltable epoxy resin (Patent Documents 1 to 3).

Above all, as a method for sealing the semiconductor element mounting surface at the wafer level, after attaching a film having an adhesive layer on both sides to a metal, silicon wafer, or glass substrate, or after applying an adhesive by spin coating or the like, A method is known in which semiconductor elements are arranged on the substrate, bonded and mounted to form a semiconductor element mounting surface, and then sealed by pressure molding under heating with a liquid epoxy resin, an epoxy molding material or the like (Patent Documents). 4). Further, as a wafer level sealing method of the semiconductor element forming surface, a method of sealing the semiconductor element forming surface by similarly using a similar epoxy-based material is known.

However, in the above method, when a wafer or metal substrate of 200 mm (8 inches) or more is used, not only the substrate or wafer is warped due to the stress of the epoxy resin or the like as the sealing resin. , The peeling of the sealing resin has been a big problem. In order to solve these problems, it is possible to reduce the shrinkage stress or reduce the elastic modulus of the resin itself by adding a filler (inorganic filler) of nearly 90% by mass to the sealing resin composition. (Patent Documents 1 to 3 and 5).

However, when the filler is highly filled, the viscosity of the sealing resin composition increases, the moldability is greatly reduced, high molding pressure is required, the substrate and the semiconductor element are damaged, and the adhesive strength also tends to decrease. There is a high possibility that new problems will occur, such as peeling from the plastic.

In order to solve these problems, a fiber-containing resin substrate in which an uncured thermosetting resin composition is mounted on a fiber-containing organic resin substrate for collectively sealing a semiconductor element mounting surface has been proposed (Patent Document 6). ). This is a method of suppressing warpage by matching the coefficient of thermal expansion of a fiber-containing organic resin substrate and a substrate such as a wafer or metal, and is an effective means for improving the handleability of a cured product, but a silicon wafer is used. In this case, silicon has a very low coefficient of thermal expansion of about 3 ppm / K, and if a thermosetting resin such as a general epoxy resin or silicone resin is used, the coefficient of thermal expansion cannot be lowered completely or the elastic modulus has an effect. There was a problem that the warp was not at a satisfactory level due to stress, and fine adjustment of the material was required each time the occupied area of the chip was different, resulting in poor versatility.

Japanese Unexamined Patent Publication No. 2002-179858 Japanese Unexamined Patent Publication No. 2009-60146 Japanese Unexamined Patent Publication No. 2007-1266 Japanese Patent Publication No. 2004-504723 JP-A-2007-146155 Japanese Unexamined Patent Publication No. 2013-197327

Therefore, an object of the present invention is to provide a sealing material for collectively sealing the semiconductor element mounting surface, which can realize low warpage, and a method for manufacturing a semiconductor device and a semiconductor package using the sealing material.

As a result of diligent research to solve the above problems, the present inventors have found that the following encapsulant can achieve the above object, and have completed the present invention.

<1>
A sealing material having an uncured resin layer on one side of a resin-impregnated fiber base material layer.
The resin-impregnated fiber base material layer is a fiber base material impregnated with a thermosetting resin composition (X) containing a cyclic imide compound and semi-cured or cured.
The uncured resin layer is formed from a thermosetting resin composition (Y) containing a cyclic imide compound.
The cyclic imide compound contained in the thermosetting resin composition (X) and the thermosetting resin composition (Y) has at least one dimer acid skeleton and at least one linear chain having 6 or more carbon atoms in the molecule. A sealing material which is a cyclic imide compound containing an alkylene group and at least two cyclic imide groups.

（一般式（１）中、Ａは独立して芳香族環または脂肪族環を含む４価の有機基を示す。Ｂは２価のヘテロ原子を含んでもよい脂肪族環を有する炭素数６から１８のアルキレン基である。Ｑは独立して炭素数６以上の直鎖アルキレン基を示す。Ｒは独立して炭素数６以上の直鎖又は分岐鎖のアルキル基を示す。ｎは１〜１０の整数を表す。ｍは０〜１０の整数を表す。） <2>
The encapsulant according to <1>, wherein the cyclic imide compound is represented by the following general formula (1).

(In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B is from 6 carbon atoms having an aliphatic ring which may contain a divalent hetero atom. It is an alkylene group of 18. Q independently represents a linear alkylene group having 6 or more carbon atoms. R independently represents a linear or branched alkyl group having 6 or more carbon atoms. N is 1 to 10 Represents an integer of. M represents an integer of 0 to 10.)

（上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。） <3>
The encapsulant according to <2>, wherein A of the formula (1) is represented by any of the following structures.

(The bond to which the substituent in the above structural formula is not bonded is the one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).)

<4>
The sealing according to <2> or <3>, wherein the thermosetting resin composition (X) and / or the thermosetting resin composition (Y) contains the following components (A) to (C). Material.
(A) Cyclic imide compound containing at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms and at least two cyclic imide groups in the molecule (B) Inorganic filler (C) Acceleration of curing Agent

<5>
A semiconductor device sealed by the sealing material according to any one of <1> to <4>.

<6>
The process of mounting a semiconductor element on the semiconductor element mounting surface of a substrate or wafer,
The semiconductor is subjected to a step of coating the semiconductor element mounting surface with the uncured resin layer of the sealing material according to any one of <1> to <4>, and by heating and curing the uncured resin layer. A method for manufacturing a semiconductor package, which comprises a step of collectively sealing an element mounting surface and / or a forming surface.

<7>
A method for manufacturing a semiconductor package, which comprises a step of batch-sealing according to <6> and then a step of individualizing.

With the sealing material of the present invention, warpage of the wafer can be suppressed even when a large-diameter silicon wafer is sealed. Further, the warp of the wafer can be suppressed without depending on the mounting area and the total number of mounted chips.

It is sectional drawing which shows an example of the sealing material of this invention. It is a figure which shows an example of the semiconductor package manufactured by using the sealing material of this invention. It is a figure which shows an example of the semiconductor package (semiconductor device) manufactured by using the sealing material of this invention, and individualized.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.
FIG. 1 is a cross-sectional view showing an example of the sealing material of the present invention. The encapsulant 10 of the present invention is a resin-impregnated fiber base material layer 1 in which a fiber base material is impregnated with a thermosetting resin composition (X) and the thermosetting resin composition (X) is semi-cured or cured. It is characterized by having an uncured resin layer 2 formed from the uncured thermosetting resin composition (Y) on one side of the resin-impregnated fiber base material layer.
Further, in the encapsulant of the present invention, the thermosetting resin composition (X) and the thermosetting resin composition (Y) have at least one dimer acid skeleton and at least one carbon number of 6 or more in the molecule. It is characterized by containing a linear alkylene group of the above and a cyclic imide compound containing at least two cyclic imide groups.
Further, as shown in FIG. 1, the encapsulant of the present invention preferably has an uncured resin layer having an area smaller than that of the resin-impregnated fiber base material layer on one side of the resin-impregnated fiber base material layer, more preferably. The area of the surface of the uncured resin layer in contact with the resin-impregnated fiber base material layer is 85 to 98% of the area of the surface of the resin-impregnated fiber base material layer in contact with the uncured resin layer.

<Resin impregnated fiber base material layer>
As described above, the sealing material of the present invention has a resin-impregnated fiber base material layer. The resin-impregnated fiber base material layer is obtained by impregnating a fiber base material with a thermosetting resin composition (X) containing a cyclic imide compound, and semi-curing or curing the thermosetting resin composition (X). is there. Since the sealing material of the present invention is provided with the resin-impregnated fiber base material layer, shrinkage stress when the uncured resin layer described later is cured can be suppressed, so that a large-diameter substrate such as a large-diameter wafer or a metal can be suppressed. Even when the semiconductor element is sealed, the warp of the substrate or wafer and the peeling of the semiconductor element from the substrate can be suppressed. In particular, even when a large-diameter thin-film wafer having a wafer diameter of 300 mm or more and a thickness of 200 μm or less is sealed, damage can be suppressed. Therefore, a large-diameter thin-film wafer having a diameter of 300 mm or more and a thickness of 200 μm or less can be sealed. The present invention is effective as a stop.

Thermosetting resin composition (X)
The resin-impregnated fiber base material layer constituting the sealing material of the present invention contains a thermosetting resin composition (X) containing a cyclic imide compound. The thermosetting resin composition (X) contains (A) a cyclic imide compound, and preferably further contains (B) an inorganic filler and (C) a curing accelerator.
(A) Cyclic imide compound The component (A) is a cyclic imide compound, which contains at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups in the molecule. Have. Since the cyclic imide compound of the component (A) has a linear alkylene group having 6 or more carbon atoms, the cured product of the composition containing this can be reduced in elasticity, and the stress caused by the cured product on the semiconductor device can be reduced. It is effective. Further, since the cyclic imide compound of the component (A) has a linear alkylene group having 6 or more carbon atoms, the cured product of the composition containing this has not only excellent dielectric properties but also relatively phenyl groups. The content ratio is reduced and the tracking resistance is also improved.

一般式（１）中、Ａは独立して芳香族環または脂肪族環を含む４価の有機基を示す。Ｂは２価のヘテロ原子を含んでもよい脂肪族環を有する炭素数６から１８のアルキレン鎖である。Ｑは独立して炭素数６以上の直鎖アルキレン基を示す。Ｒは夫々独立に炭素数６以上の直鎖又は分岐鎖のアルキル基を示す。ｎは１〜１０の整数を表す。ｍは０〜１０の整数を表す。 Further, among them, the cyclic imide compound of the component (A) is preferably a maleimide compound, and it is more preferable to use a maleimide compound represented by the following general formula (1).

In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B is an alkylene chain having 6 to 18 carbon atoms having an aliphatic ring which may contain a divalent heteroatom. Q independently represents a linear alkylene group having 6 or more carbon atoms. R independently represents a linear or branched alkyl group having 6 or more carbon atoms. n represents an integer of 1-10. m represents an integer from 0 to 10.

Q in the formula (1) is a linear alkylene group, and the number of carbon atoms thereof is 6 or more, preferably 6 or more and 20 or less, and more preferably 7 or more and 15 or less.
Further, R in the formula (1) is an alkyl group, which may be a linear alkyl group or a branched alkyl group, and the number of carbon atoms thereof is 6 or more, preferably 6 or more and 12 or less.

（なお、上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。）
また、式（１）中のＢは２価のヘテロ原子を含んでもよい脂肪族環を有する炭素数６から１８のアルキレン鎖であり、該アルキレン基の炭素数は好ましくは炭素数８以上１５以下である。
式（１）中のｎは１〜１０の整数であり、好ましくは２〜７の整数である。式（１）中のｍは０〜１０の整数であり、好ましくは０〜７の整数である。 A in the formula (1) represents a tetravalent organic group containing an aromatic ring or an aliphatic ring, and is particularly preferably any of the tetravalent organic groups represented by the following structural formula.

(Note that the bond to which the substituent in the above structural formula is not bonded is the one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).)
Further, B in the formula (1) is an alkylene chain having 6 to 18 carbon atoms having an aliphatic ring which may contain a divalent heteroatom, and the carbon number of the alkylene group is preferably 8 or more and 15 or less. Is.
N in the formula (1) is an integer of 1 to 10, preferably an integer of 2 to 7. M in the formula (1) is an integer of 0 to 10, preferably an integer of 0 to 7.

The cyclic imide compound of the component (A) is not particularly limited including its properties at room temperature (25 ° C.), but is preferably solid at room temperature (25 ° C.). Further, the weight average molecular weight (Mw) converted by the polystyrene standard by gel permeation chromatography (GPC) measurement is preferably 2,000 to 50,000, more preferably 2,500 to 40,000. If the molecular weight is 2,000 or more, the obtained maleimide compound tends to solidify, and if it is less than 2,000, the composition before curing tends to have tack. When the molecular weight is 50,000 or less, the obtained composition does not have a possibility that the viscosity becomes too high and the fluidity decreases, and the moldability such as laminating molding becomes good.
The weight average molecular weight (Mw) referred to in the present invention refers to the weight average molecular weight of polystyrene obtained by GPC measured under the following conditions as a standard substance.
[Measurement condition]
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min
Detector: RI
Column: TSK-GEL H type (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample injection volume: 5 μL

As the cyclic imide compound of the component (A), commercially available products such as BMI-2500, BMI-2560, BMI-3000, and BMI-5000 (all manufactured by Desisigner Moleculars Inc.) can be used.
Further, the cyclic imide compound may be used alone or in combination of two or more.
In the thermosetting resin composition (X), the cyclic imide compound (A) is preferably contained in an amount of 5 to 50% by mass, more preferably 10 to 45% by mass.

(B) Inorganic Filler As the inorganic filler, those generally used for semiconductor encapsulants can be used in order to improve the coefficient of thermal expansion and rigidity of the substrate. For example, molten silica and crystalline silica can be used. Examples thereof include silicas such as, alumina, silicon nitride, aluminum nitride, aluminosilicate, boron nitride, glass fiber, and antimony trioxide.
The average particle size and shape of the inorganic filler of the component (B) are not particularly limited, but the average particle size is usually 0.1 to 40 μm. As the component (B), spherical silica having an average particle size of 0.5 to 40 μm is preferably used. The average particle size is a value obtained as the mass average value D ₅₀ (or median diameter) in the particle size distribution measurement by the laser light diffraction method.
The blending amount of the inorganic filler of the component (B) is preferably 100 to 700 parts by mass with respect to 100 parts by mass of the cyclic imide compound (A).

(C) Curing Accelerator As the curing accelerator, those generally used for enhancing the reactivity and curability of the cyclic imide compound of the component (A) can be used, for example, dicumyl peroxide, etc. t-hexyl hydroperoxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α'-bis (t-butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, Examples thereof include thermal radical polymerization initiators such as di-t-butyl peroxide. Further, the curing accelerator of the component (C) may be used alone or in combination of two or more, regardless of the type.
The amount of the curing accelerator of the component (C) is preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic imide compound (A).

Other Ingredients Other ingredients can be further added to the thermosetting resin composition (X), if necessary. As the other components, organopolysiloxane, silicone oil, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, light stabilizer, pigment, dye, etc. are used to improve the resin properties as long as the effects of the present invention are not impaired. It may be blended, a coupling agent for improving wettability and adhesion to the sealing resin layer, an ion trapping agent for improving electrical characteristics, a phosphorus compound or metal water for imparting flame retardancy. A non-halogen flame retardant typified by Japanese products may be blended.
If necessary, a thermosetting resin component having a functional group capable of reacting with a cyclic imide group in the component (A) such as an epoxy resin, a phenol resin, a cyanate resin, and an epoxy-silicone hybrid resin is used in combination as long as the curing is not impaired. It doesn't matter.
The thermosetting resin composition (X) preferably further contains the pigment (D).
Examples of the pigment (D) include carbon black and titanium black. The blending amount of the pigment of the component (D) is preferably 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the cyclic imide compound (A).

Fiber base material The fiber base material includes, for example, carbon fiber, glass fiber such as E-glass fiber and T-glass fiber, inorganic fiber such as quartz glass fiber and metal fiber; aromatic polyamide fiber, polyimide fiber, polyamideimide fiber. Organic fibers such as silicon carbide fiber, titanium carbide fiber, boron fiber, alumina fiber and the like are exemplified. Among them, glass fiber, quartz glass fiber, and carbon fiber are preferable, and E-glass fiber, T-glass fiber, and quartz glass fiber are more preferable from the viewpoint of insulation property and substrate rigidity.

Examples of the form of the fiber base material include rovings in which long fiber filaments are aligned in a certain direction, fiber cloths, sheet-like materials such as non-woven fabrics, and chop strand mats, which can form laminates. If it is a thing, there is no particular limitation.

<Method of manufacturing resin-impregnated fiber base material>
As a method of impregnating the fiber base material with the thermosetting resin composition (X), either a solvent method or a hot melt method may be used. The solvent method is a method of preparing a resin varnish in which the thermosetting resin composition (X) is dissolved in an organic solvent and impregnating the fiber base material with the resin varnish, and the hot melt method is the heat of a solid. This is a method in which the curable resin composition (X) is heated and melted to impregnate the fiber base material.

The method for semi-curing the thermosetting resin composition (X) impregnated in the fiber base material is not particularly limited, but the thermosetting resin composition (X) impregnated in the fiber base material is heated. An example is a method of semi-curing by removing the solvent. The method for curing the thermosetting resin composition (X) impregnated in the fiber base material is not particularly limited, but the thermosetting resin composition (X) impregnated in the fiber base material is heated. An example is a method of curing.
The resin-impregnated fiber base material is preferably impregnated with the thermosetting resin composition (X), cured or semi-cured, and then post-cured at a temperature of 150 to 200 ° C. for 2 to 8 hours.

The thickness of the resin-impregnated fiber base material obtained by impregnating the fiber base material with the thermosetting resin composition (X) and semi-curing or curing the thermosetting resin composition is the thickness of the fiber base material such as the fiber cloth used. When producing a thick resin-impregnated fiber base material, the number of fiber base materials used such as fiber cloth is increased, and the fibers are laminated.

In the present invention, semi-curing means B-stage (a curing intermediate of a thermosetting resin composition. The resin in this state softens when heated and swells when exposed to a certain solvent, but is completely melted and dissolved. It means a state (which does not happen).

The thickness of the resin-impregnated fiber base material is basically selected according to the thickness on the semiconductor element, but from the viewpoint of handling and the like, the thermosetting resin composition (X) impregnated in the fiber base material is used. In either case of semi-curing or curing, it is preferably 30 μm to 3,000 μm, and more preferably 40 μm to 2,500 μm. When the thickness of the resin-impregnated fiber base material is 30 μm or more, it is preferable because it is suppressed from being too thin and easily deformed, and when it is 3,000 μm or less, it is possible to suppress the thickness of the semiconductor device itself.

The resin-impregnated fiber base material layer constituting the sealing material of the present invention reduces warpage after the semiconductor element mounting surface is collectively sealed with the sealing material of the present invention, and two or more semiconductor elements are arranged and bonded. It is important to reinforce the finished substrate. Therefore, it is desirable that the resin-impregnated fiber base material is hard and rigid.

<Uncured resin layer>
The encapsulant of the present invention has an uncured resin layer. The uncured resin layer is formed from the uncured thermosetting resin composition (Y) on one side of the resin-impregnated fiber base material layer. The uncured resin layer is a resin layer for sealing a semiconductor element. The uncured resin layer of the present invention is characterized by containing a specific cyclic imide compound which is the component (A) described above.

The uncured resin layer is preferably formed on one side of the resin-impregnated fiber base material layer in an area smaller than that of the resin-impregnated fiber base material layer, and more preferably the resin-impregnated fiber base material layer of the uncured resin layer. The area of the contact surface is 85 to 98% of the area of the surface of the resin-impregnated fiber base material layer that contacts the uncured resin layer. In order to make the area of the uncured resin layer the above-mentioned desired size, the total amount of the required resin of the thermosetting resin composition (Y) may be converted into weight and the required amount may be used.

Thermosetting resin composition (Y)
The uncured resin layer constituting the sealing material of the present invention is formed from the thermosetting resin composition (Y) containing the cyclic imide compound. The thermosetting resin composition (Y) contains a specific cyclic imide compound which is the component (A) described above, and preferably further contains the above-mentioned inorganic filler (B) and a curing accelerator (C). Specific examples and blending amounts of the components (A), (B) and (C) are the same as those of the thermosetting resin composition (X) described above.

Other Ingredients Other ingredients can be further added to the thermosetting resin composition (Y), if necessary. Organopolysiloxane, silicone oil, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, light stabilizer, pigment, dye, release to improve the resin properties as the other components without impairing the effects of the present invention. A mold or the like may be blended, a coupling agent for improving wetting and adhesion to the sealing resin layer, an ion trapping agent for improving electrical properties, and phosphorus for imparting flame retardancy. A non-halogen flame retardant typified by a compound or metal hydrate may be blended.
The thermosetting resin composition (Y) preferably further contains (D) a pigment and (E) a coupling agent.
Examples of the pigment (D) include carbon black and titanium black. The blending amount of the pigment of the component (D) is preferably 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the cyclic imide compound (A).
Examples of the coupling agent (E) include epoxy-functional alkoxysilanes (for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltri). Methoxysilane, etc.), mercapto-functional alkoxysilane (eg, γ-mercaptopropyltrimethoxysilane, etc.), amine-functional alkoxysilane (eg, γ-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-amino, etc.) (Propyltrimethoxysilane, etc.) and the like.
The blending amount of the coupling agent for the component (E) is preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic imide compound (A).

<Method of manufacturing encapsulant>
In the encapsulant of the present invention, by using the same cyclic imide compound for the resin-impregnated fiber base material layer and the uncured resin layer, warpage of the wafer after encapsulation can be suppressed, and the resin-impregnated fiber group can be suppressed. The adhesion between the material layer and the uncured resin layer is improved.
Examples of the method for producing the sealing material of the present invention include the following methods.
First, a thermosetting resin composition (X) and a thermosetting resin composition (Y) are prepared, respectively. The preparation method is not particularly limited, and examples thereof include a method in which each of the above-mentioned components is blended in a predetermined composition ratio and sufficiently uniformly mixed, stirred, dissolved, dispersed and / or melt-kneaded by a mixer or the like. Each component may be blended at the same time or separately, or may be mixed while heating if necessary. The device for mixing and the like is not particularly limited, and specific examples thereof include a Raikai machine equipped with a stirring and heating device, a two-roll mill, a three-roll mill, a ball mill, a planetary mixer, a mascoroider, and the like. The devices may be used in combination as appropriate.
Next, a resin-impregnated fiber base material is prepared from the thermosetting resin composition (X) and the fiber base material by the method described above, and used as a resin-impregnated fiber base material layer.
Next, an uncured resin layer is formed on one side of the resin-impregnated fiber base material layer using the thermosetting resin composition (Y). Here, when the thermosetting resin composition (Y) used for the uncured resin layer is liquid at room temperature (25 ° C.) in the uncured state, it is applied to one side of the resin-impregnated fiber base material layer under reduced pressure or vacuum. By applying the thermosetting resin composition (Y) by printing, dispensing, or the like and heating it, a solid uncured resin layer can be formed at 50 ° C. or lower. On the other hand, when the thermosetting resin composition (Y) used for the uncured resin layer is solid at room temperature (25 ° C.) in the uncured state, the thermosetting resin composition (Y) is applied to one side of the resin-impregnated fiber base material. A method of pressurizing while heating Y) or a method of adding an appropriate amount of a solvent to liquefy the thermosetting resin composition (Y) to form a thin film by printing or the like, and heating and removing the solvent under reduced pressure. Although the uncured resin layer can be uniformly formed on one side of the resin-impregnated fiber base material, it is preferable not to use a solvent in order not to generate voids in the uncured resin layer.

As the shape of the thermosetting resin composition (Y) for forming the uncured resin layer of the present invention, it is preferable to use a sheet-like shape of the composition. As a method for producing this sheet, each component of the thermosetting resin composition (Y) is blended in a predetermined composition ratio, mixed sufficiently uniformly with a mixer or the like, and then a T-die is placed at the tip of the biaxial. An example is a T-die extrusion method in which a sheet is formed using an extruder. Alternatively, a pulverized product of the composition obtained by performing melt mixing treatment with a heat roll, kneader, extruder or the like, then cooling and solidifying, and pulverizing to an appropriate size is heated at 70 to 120 ° C. between the pressurizing members. It may be melted and compressed to form a sheet.

In either method, an uncured resin layer composed of an uncured thermosetting resin composition (Y) having a thickness of 30 μm to 3,000 μm and having no voids or volatile components on one surface of the resin-impregnated fiber base material layer. To form.

<Semiconductor package>
The present invention is characterized in that the semiconductor element mounting surface of a substrate or wafer on which two or more semiconductor elements are mounted is collectively sealed by the uncured resin layer of the above-mentioned sealing material. I will provide a.

A cross-sectional view of an example of the semiconductor package of the present invention is shown in FIG. In the semiconductor package 11 of FIG. 2, the semiconductor element mounting surface of the wafer 5 on which two or more semiconductor elements 3 are mounted by the adhesive 4 is a cured product of the uncured resin layer 2 of the sealing material 10 (that is, after curing). It is collectively sealed by the resin layer 2') of.

With such a semiconductor package collectively sealed by the sealing material of the present invention, warpage of the substrate or wafer is suppressed.
As described above, the encapsulant of the present invention is particularly specialized for chip-on-wafer (CoW) packages, and even when a large-diameter wafer is encapsulated, warpage of the wafer and peeling of semiconductor elements are suppressed. At the same time, the semiconductor element mounting surface of the wafer on which the semiconductor element is mounted can be collectively sealed at the wafer level. Therefore, the encapsulant of the present invention is useful for encapsulating chip-on-wafer packages.

<Semiconductor device>
Furthermore, the present invention provides a semiconductor package (semiconductor device) in which the above-mentioned semiconductor package is individualized.

A cross-sectional view of an example of the semiconductor device of the present invention is shown in FIG. The semiconductor device 12 of FIG. 3 is obtained by dicing the semiconductor package 11 of FIG. 2 into individual pieces. The semiconductor device 12 manufactured in this way is a high-quality semiconductor device that is sealed with a sealing material having excellent sealing performance such as heat resistance and moisture resistance, and that warpage of the wafer and peeling of the semiconductor element are suppressed. Become. The semiconductor device 12 is a semiconductor device in which a semiconductor element 3 is mounted on a wafer 5 via an adhesive 4, and is sealed from above by a cured resin layer 2'and a resin-impregnated fiber base material layer 1 (FIG. 6). 3).

<Manufacturing method of semiconductor package (semiconductor device)>
The present invention also provides a method for manufacturing a semiconductor package (semiconductor device). The method for manufacturing a semiconductor package includes a semiconductor element mounting step, a coating step, and a sealing step, and further includes an individualization step if necessary.

<Semiconductor device mounting process>
The semiconductor element mounting process is a step of mounting a semiconductor element on a semiconductor element mounting surface of a substrate or a wafer. It is preferable that the number of semiconductor elements mounted in this step is two or more. The method for mounting the semiconductor element is not particularly limited, and a known method can be used. For example, it is preferable to mount the semiconductor element via an adhesive, preferably an adhesive whose adhesive strength decreases at a high temperature.
<Coating process>
The coating step is a step of coating the semiconductor element mounting surface on which the semiconductor element 3 of the wafer 5 is mounted with the uncured resin layer 2 of the sealing material 10.

<Sealing process>
In the sealing step, the uncured resin layer 2 of the sealing material is heated and cured to form the cured resin layer 2', so that the semiconductor element mounting surface on which the semiconductor element 3 of the wafer 5 is mounted is collectively sealed. It is a process to do.
From the above, a wafer level semiconductor package can be obtained.

<Individualization process>
The individualization step is a step of dicing and individualizing the wafer-level semiconductor package obtained after the sealing step. As a result, an individualized semiconductor package (semiconductor device) 12 can be obtained.

Hereinafter, the method for manufacturing the semiconductor package of the present invention will be described in more detail. In the above-mentioned coating process and sealing process, by using a vacuum laminator device, a vacuum press device, etc. used for lamination of solder resist films, various insulating films, etc., coating and sealing without voids and warpage are performed. You can stop it. As the lamination method, any method such as roll lamination, diaphragm type vacuum lamination, and air pressurization type lamination can be used.

Here, as an example, a resin-impregnated fiber base material obtained by impregnating a glass cloth (fiber base material) having a thickness of 42 μm with a thermosetting resin composition (X) using a vacuum lamination device manufactured by Nichigo Morton Co., Ltd., and one side thereof. A sealing material having an uncured resin layer having a thickness of 150 μm formed from a thermosetting resin composition (Y), and a substrate on which a silicon chip of 10 × 10 mm is mounted on a silicon wafer having a thickness of 250 μm and a diameter of 300 mm is sealed. The case of stopping will be described.

The vacuum lamination device has two plates with built-in heaters at the top and bottom. Of the two plates, the upper plate is in close contact with the heater with the diaphragm rubber depressurized.
The plate temperature of the two plates is set to 150 ° C., a wafer on which a silicon chip is mounted is set on the lower plate, and the uncured resin layer surface of the encapsulant is placed on the semiconductor element (silicon chip) mounting surface of the above-mentioned wafer. Set together. After that, the lower plate rises, and the upper and lower plates are brought into close contact with each other by the O-ring installed so as to surround the wafer set on the lower plate to form a vacuum chamber, and the inside of the vacuum chamber is depressurized. When the inside of the vacuum chamber is sufficiently decompressed, the valve of the pipe connected to the vacuum pump is closed from between the diaphragm rubber on the upper plate and the heater, and compressed air is sent. As a result, the upper diaphragm rubber expands and the wafer and the fiber-containing resin substrate are sandwiched between the upper diaphragm rubber and the lower plate, vacuum lamination is performed, and at the same time, the thermosetting resin is cured and the sealing is completed. .. A curing time of about 3 to 20 minutes is sufficient. When the vacuum lamination is completed, the inside of the vacuum chamber is returned to normal pressure, the lower plate is lowered, and the sealed wafer is taken out. By the above process, the substrate can be sealed without voids or warpage. The removed substrate is usually post-cured at a temperature of 150 to 200 ° C. for 1 to 8 hours to stabilize the electrical characteristics and mechanical characteristics.
The semiconductor element mounting and individualization steps may be performed according to a conventional method.

With such a method for manufacturing a semiconductor device, the semiconductor element mounting surface can be easily coated with the uncured resin layer of the sealing material in the coating process without filling defects. Further, by using the resin-impregnated fiber base material, the shrinkage stress at the time of curing of the uncured resin layer can be suppressed, so that the semiconductor element mounting surface can be collectively sealed in the sealing process, and the wafer warpage, It is possible to obtain a semiconductor package in which peeling of the semiconductor element is suppressed. Furthermore, in the individualization process, the semiconductor device is diced from a wafer-level semiconductor package that is sealed with a resin-impregnated fiber base material having excellent sealing performance such as heat resistance and moisture resistance and whose warpage is suppressed, and then individualized. Therefore, a high-quality semiconductor device can be easily manufactured.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<Preparation of resin-impregnated fiber base material containing cyclic imide compound>
100 parts by mass of a cyclic imide compound represented by the following formula (2) (trade name: BMI-3000J, manufactured by Designer Moleculars Inc.),
Silica with a particle size of 0.5 μm (trade name: SO-25R, manufactured by Admatex Co., Ltd.) 150 parts by mass,
As a black pigment, carbon black (trade name: 3230B, manufactured by Mitsubishi Chemical Corporation) in 3 parts by mass and peroxide (Park Mill D, manufactured by Nichiyu Co., Ltd.) in 2.0 parts by mass.
300 parts by mass of toluene was added and mixed by stirring to prepare a toluene dispersion of a thermosetting resin composition containing a cyclic imide compound.

A thermosetting resin containing a cyclic imide compound by immersing T glass cloth (manufactured by Nitto Boseki Co., Ltd., thickness: 42 μm) as a fiber base material in a toluene dispersion of a thermosetting resin composition containing the cyclic imide compound. The toluene dispersion of the composition was impregnated into the T glass cloth. Toluene was volatilized by leaving the glass cloth at 120 ° C. for 15 minutes. The glass cloth is heat-molded at 175 ° C. for 5 minutes to obtain a molded product, which is further heated at 180 ° C. for 2 hours (secondary curing) to obtain a thermosetting resin composition containing an impregnated cyclic imide compound. Was cured to prepare a resin-impregnated fiber base material X1 in which a thermosetting resin composition containing a cyclic imide compound was impregnated into a fiber base material in a cured state. The resin-impregnated fiber base material X1 has a cured product layer of a thermosetting resin composition containing a cyclic imide compound formed on both sides of the fiber base material, and has a size of 400 mm × 500 mm and a thickness of 0. It was 12 mm. Then, the resin-impregnated fiber base material X1 was cut into a disk shape having a diameter of 300 mm (12 inches). The coefficient of linear expansion of the resin-impregnated fiber base material X1 from 0 ° C. to 200 ° C. was 7 ppm / ° C.

<Preparation of resin-impregnated fiber base material containing thermosetting epoxy resin composition, for comparative example>
Cresol novolac type epoxy resin (trade name: EPICLON-N695, manufactured by DIC) 60 parts by mass,
Phenolic novolak resin (trade name: TD2090, manufactured by DIC) 30 parts by mass,
Silica with a particle size of 0.5 μm (trade name: SO-25R, manufactured by Admatex Co., Ltd.) 150 parts by mass,
As a black pigment, carbon black (trade name: 3230B, manufactured by Mitsubishi Chemical Corporation) in 3 parts by mass and triphenylphosphine (TPP, manufactured by Hokuko Kagaku Kogyo Co., Ltd.) in 0.6 parts by mass.
300 parts by mass of toluene was added and mixed by stirring to prepare a toluene dispersion of an epoxy resin composition.

The toluene dispersion of the epoxy resin composition was impregnated with the toluene dispersion of the epoxy resin composition by immersing the T glass cloth (manufactured by Nitto Boseki, thickness: 88 μm) as a fiber base material in the toluene dispersion of the epoxy resin composition. .. Toluene was volatilized by leaving the glass cloth at 120 ° C. for 15 minutes. The glass cloth is heat-molded at 175 ° C. for 5 minutes to obtain a molded product, which is further heated at 180 ° C. for 4 hours (secondary curing) to cure the impregnated epoxy resin composition, and the epoxy resin composition is cured. A resin-impregnated fiber base material X2 was prepared in which the material was impregnated into the fiber base material in a cured state. The resin-impregnated fiber base material X2 had cured product layers of an epoxy resin composition formed on both sides of the fiber base material, and had a size of 400 mm × 500 mm and a thickness of 0.12 mm. Then, the resin-impregnated fiber base material X2 was cut into a disk shape having a diameter of 300 mm (12 inches). The coefficient of linear expansion of the thermosetting epoxy resin impregnated fiber base material X2 from 0 ° C. to 200 ° C. was 7 ppm / ° C.

<Preparation of uncured thermosetting cyclic imide resin>
100 parts by mass of the cyclic imide compound represented by the formula (2) (trade name: BMI-3000J, manufactured by Designer Moleculars Inc.),
Silica with a particle size of 4 μm (trade name: MUF-4H, manufactured by Ryumori Co., Ltd.) 250 parts by mass,
Carbon black (trade name: 3230B, manufactured by Mitsubishi Chemical Corporation) as a black pigment, 3 parts by mass,
Sufficiently mix 2.0 parts by mass of peroxide (Park Mill D, manufactured by Nichiyu Co., Ltd.) and 1.0 part by mass of silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) with a high-speed mixer. Then, the thermosetting resin composition Y1 containing a cyclic imide compound in the form of a sheet was obtained by heating, melting and kneading in a continuous kneading apparatus equipped with a T-die.

<Making uncured thermosetting epoxy resin for comparative examples>
Cresol novolac type epoxy resin (trade name: EPICLON-N655, manufactured by DIC) 60 parts by mass,
Phenol novolak resin (trade name: TD2131, manufactured by DIC) 40 parts by mass,
Silica with a particle size of 4 μm (trade name: MUF-4H, manufactured by Ryumori Co., Ltd.) 250 parts by mass,
Carbon black (trade name: 3230B, manufactured by Mitsubishi Chemical Corporation) as a black pigment, 3 parts by mass,
Thoroughly mix 0.6 parts by mass of triphenylphosphine (TPP, manufactured by Hokuko Kagaku Kogyo Co., Ltd.) and 1.0 part by mass of silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) with a high-speed mixer. Then, the thermosetting epoxy resin composition Y2 in the form of a sheet was obtained by heating, melting and kneading in a continuous kneading apparatus equipped with a T-die.

<Preparation of encapsulant>
A resin-impregnated fiber base material X1 or X2, which has been cut into a circular shape having a diameter of 300 mm in advance, is set on a lower mold of a compression molding device capable of heating and compressing under reduced pressure, and a sheet-shaped thermocurable resin composition is placed on the lower mold. Y1 or the thermosetting epoxy resin composition Y2 was placed in the required weight. The upper and lower mold temperatures are set to 80 ° C., a fluororesin-coated PET film (release film) is set in the upper mold, the inside of the mold is depressurized to the vacuum level, and compression molding is performed for 30 seconds to make a resin-impregnated fiber base material. A sealing material having an uncured resin layer on one side of the layer was produced.
In each of the sealing materials of each example, the area of the surface of the uncured resin layer in contact with the resin-impregnated fiber base material layer is 95% of the area of the resin-impregnated fiber base material layer in contact with the uncured resin layer. Met.

<Coating and sealing of wafers on which semiconductor elements are mounted>
Next, the wafer was coated and sealed with the sealing material produced above using a vacuum lamination device manufactured by Nichigo Morton Co., Ltd. in which the plate temperature was set to 150 ° C.
First, 400 silicon chips (shapes), which are semiconductor elements that are individualized, are placed on a silicon wafer having a diameter of 300 mm (12 inches) and a thickness of 200 μm, 400 μm, or 725 μm via an adhesive whose adhesive strength decreases at high temperatures. : 10 mm × 10 mm, thickness 250 μm) were aligned and mounted to produce a silicon wafer. The silicon wafer is set on the lower plate of the vacuum lamination device, the uncured resin layer surface of the encapsulant produced above is aligned with the semiconductor element mounting surface of the silicon wafer, and the semiconductor element mounting surface is formed by the uncured resin layer. Covered. Then, the plate of the vacuum lamination device was closed and vacuum compression molded for 10 minutes to cure and seal. After curing and sealing, it was post-cured at 180 ° C. for 4 hours to obtain a semiconductor package. The combinations of the resin-impregnated fiber base material layer and the uncured resin layer used for the sealing material are as shown in Table 1, and the resin-impregnated fiber base material layer in the column of "None" is the resin-impregnated fiber. It means that the molding was performed without using either the base materials X1 and X2.

The warp and appearance of the obtained semiconductor package were confirmed. Regarding the warpage, the semiconductor package was placed on a flat desk with the wafers facing down, and the warpage of the wafers at any four locations was measured with a caliper, and the average value was calculated. Regarding the appearance, the appearance was observed for each semiconductor package using three types of wafers having different thicknesses in each example or comparative example, and it was confirmed whether there was any abnormality. The results are shown in Table 1.

From the above, the encapsulant of the present invention containing a specific cyclic imide compound in the resin-impregnated fiber base material layer and the uncured resin layer has a large-diameter wafer, particularly a wafer having a diameter of 300 mm or more and a thickness. Even when a large-diameter thin-film wafer having a diameter of 200 μm or less is collectively sealed, warpage of the substrate or wafer can be suppressed. It was also confirmed that the appearance of the semiconductor package was good and the handleability of the encapsulant was improved.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same action and effect is the present invention. Is included in the technical scope of.

1 Resin impregnated fiber base material layer 2 Uncured resin layer 2'Cured resin layer 3 Semiconductor element 4 Adhesive 5 Wafer 10 Encapsulant 11 Semiconductor package 12 Semiconductor package (semiconductor device)

Claims (7)

A sealing material having an uncured resin layer on one side of a resin-impregnated fiber base material layer.
The resin-impregnated fiber base material layer is a fiber base material impregnated with a thermosetting resin composition (X) containing a cyclic imide compound and semi-cured or cured.
The uncured resin layer is formed from a thermosetting resin composition (Y) containing a cyclic imide compound.
The cyclic imide compound contained in the thermosetting resin composition (X) and the thermosetting resin composition (Y) has at least one dimer acid skeleton and at least one linear chain having 6 or more carbon atoms in the molecule. A sealing material which is a cyclic imide compound containing an alkylene group and at least two cyclic imide groups. The encapsulant according to claim 1, wherein the cyclic imide compound is represented by the following general formula (1).

(In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B is from 6 carbon atoms having an aliphatic ring which may contain a divalent hetero atom. It is an alkylene group of 18. Q independently represents a linear alkylene group having 6 or more carbon atoms. R independently represents a linear or branched alkyl group having 6 or more carbon atoms. N is 1 to 10 Represents an integer of. M represents an integer of 0 to 10.) The encapsulant according to claim 2, wherein A of the formula (1) is represented by any of the following structures.

(The bond to which the substituent in the above structural formula is not bonded is the one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).) The invention according to any one of claims 1 to 3, wherein the thermosetting resin composition (X) and / or the thermosetting resin composition (Y) contains the following components (A) to (C). Encapsulant.
(A) Cyclic imide compound containing at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms and at least two cyclic imide groups in the molecule (B) Inorganic filler (C) Acceleration of curing Agent A semiconductor device sealed by the sealing material according to any one of claims 1 to 4. The process of mounting a semiconductor element on the semiconductor element mounting surface of a substrate or wafer,
The step of covering the semiconductor element mounting surface with the uncured resin layer of the sealing material according to any one of claims 1 to 4, and the step of heating and curing the uncured resin layer to mount the semiconductor element. A method for manufacturing a semiconductor package, which comprises a step of collectively sealing the surfaces. A method for manufacturing a semiconductor package, which comprises a step of batch-sealing according to claim 6 and then a step of individualizing.

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