JP6845178B2 - Manufacturing method of thermosetting resin sheet for semiconductor encapsulation and encapsulation method of semiconductor device - Google Patents

Description

The present invention relates to a method for producing a thermosetting resin sheet for semiconductor encapsulation and a method for encapsulating a semiconductor device.

In recent years, along with the miniaturization, weight reduction, and high performance of electronic devices, the integration and thinning of semiconductor devices have progressed, and when manufacturing these semiconductor devices, the area and thickness are large and thin from the viewpoint of productivity. There is a tendency to perform batch molding of substrates and wafers.

In the case of batch molding of such a large area / thin substrate or wafer, the amount of movement and flow of the resin during molding is increased by the conventional methods such as transfer molding using solid resin and compression molding using liquid resin. In many cases, there is a risk that problems such as misalignment of electronic components such as semiconductor elements mounted on a substrate or wafer, wire flow, and flow marks may occur. Further, when a large-area / thin substrate or wafer is sealed, the substrate or wafer is liable to warp, and control of warpage is also a big issue.

Sheet-shaped semiconductor encapsulation is a method for solving misalignment of electronic components mounted on the substrate or wafer and warpage of the substrate or wafer when collectively molding such a large-area / thin substrate or wafer. A method using a thermosetting resin composition for use, a resin-impregnated fiber base material obtained by impregnating a fiber base material with a thermosetting resin and semi-curing or curing the thermosetting resin, and a resin-impregnated fiber base material. A method using a sealing material with a base material for semiconductor encapsulation having an uncured resin layer made of an uncured thermosetting resin formed on one surface has been developed (Patent Documents 1 and 2).

However, since such a sheet-shaped thermosetting resin composition and a sealing material with a base material for semiconductor encapsulation itself have a large area and a thin shape, it is said that the resin amount adjustment is insufficient. , Unfilled or resin leakage from the molding mold is likely to occur during molding, and it is necessary to strictly control the amount of resin. However, at present, it is not possible to sufficiently control variations in the shape (thickness, width) and composition of the sheet, and it cannot be said that the amount of resin can be strictly controlled simply by cutting to a fixed size. Is.

Japanese Unexamined Patent Publication No. 2014-197670 Japanese Unexamined Patent Publication No. 2012-151451

The present invention has been made to solve the above problems, and when a semiconductor element is sealed using a large-area, thin thermosetting resin sheet for semiconductor encapsulation, it is possible to use an unfilled or molded mold. Provided are a method for producing a thermosetting resin sheet for semiconductor encapsulation capable of preventing resin leakage, and a method for encapsulating a semiconductor device using the thermosetting resin sheet for semiconductor encapsulation produced by the above manufacturing method. The purpose.

In order to achieve the above object, the present invention is a method for producing a thermosetting resin sheet for semiconductor encapsulation.
(A) A step of cutting a thermosetting resin sheet into a predetermined shape.
(B) A step of die-cutting a resin sheet cut to a fixed size in the step (a) into a predetermined shape with a mass of more than 100% and 200% or less of the target mass.
(C) From the resin sheet die-cut in the step (b), a large piece of 5% by mass or more and 20% by mass or less and a small piece of 0.01% by mass or more and less than 5% by mass with respect to the mass of the resin sheet are each. Pieces of 0 or more and 1 or more and 10 or less in total are cut into individual pieces so that the mass of the resin sheet is 50% to 99% of the target mass, and each piece is separated from the resin sheet. The process of separating each piece and weighing the resin sheet after die cutting of each piece,
(D) In the step (c), the mass of the resin sheet after the individual piece is die-cut and the mass of each piece are calculated, and the total mass of the resin sheet mass after the individual piece die-cut and the mass of each piece is the said. Provided is a method for producing a thermosetting resin sheet for semiconductor encapsulation, which comprises a step of adjusting so as to be 99% by mass or more and 101% by mass or less of a target mass.

According to the above-mentioned method for manufacturing a thermosetting resin sheet for semiconductor encapsulation, when a semiconductor element is sealed using a large-area / thin thermosetting resin sheet for semiconductor encapsulation, it is possible to use an unfilled or molded mold. Resin leakage can be prevented.

Further, it is preferable to have (e) a step of laminating the resin sheet with the support substrate. By having such a step, a sealing substrate with less warpage can be obtained.

As a preparation step of the thermosetting resin sheet used in the step (a), it is preferable to have a step of molding the thermosetting resin by extrusion molding. According to extrusion molding, a sheet having a stable width and thickness can be easily produced.

The resin sheet width of the thermosetting resin sheet used in the step (a) is preferably 190 mm or more. If it is 190 mm or more, a resin sheet suitable for sealing a large-diameter wafer can be obtained.

The resin sheet thickness of the thermosetting resin sheet used in the step (a) is preferably 0.2 mm or more and 5 mm or less. When the resin sheet thickness is within this range, it is preferable because the handleability at the time of die cutting in the next step is excellent and the die cutting property is also good. Further, since the space volume of the die-cut portion does not increase, molding voids are unlikely to be generated during molding, which is preferable.

Further, the present invention also provides a method for sealing a semiconductor device, in which a thermosetting resin sheet for semiconductor encapsulation manufactured by the above manufacturing method is superposed on a substrate on which a semiconductor element is placed and pressure-molded to seal the semiconductor device. To do. According to such a method for sealing a semiconductor device, the thermosetting resin sheet for sealing a semiconductor obtained in the present invention is used to prevent unfilling or resin leakage from a molding die to seal a semiconductor element. can do.

By adjusting the resin sheet mass of the thermosetting resin composition for semiconductor encapsulation of the present invention, the amount of resin used for encapsulation can be accurately controlled, so that a large area and thin thermosetting resin for encapsulating semiconductors can be accurately controlled. When the semiconductor element is sealed using the sheet, it is possible to prevent unfilling and resin leakage from the molding mold.

It is a figure which shows an example of the step of cutting the resin sheet of the thermosetting resin composition for semiconductor encapsulation of this invention to a fixed size. It is a figure which shows an example of the process of die-cutting a resin sheet cut to a predetermined size into a predetermined shape, and weighing the die-cut resin sheet. It is a figure which shows an example of the step of further die-cutting an excess mass or more from a die-cut resin sheet. Reweigh the total mass of the resin sheet that has been die-cut by the excess mass or more, calculate the excess or deficiency mass, and add or subtract the individual pieces so that the specified mass value is obtained. Is a diagram showing an example of a process of further die-cutting the required mass, reweighing whether the resin sheet to which the individual products are added or subtracted has a predetermined mass value, and adjusting the mass. It is a figure which shows an example of the process of sealing a semiconductor device using the resin sheet of the thermosetting resin composition for semiconductor encapsulation.

As described above, when a semiconductor element is sealed using a large-area, thin thermosetting resin sheet for semiconductor encapsulation, it is possible to prevent unfilled or resin leakage from the molding mold. Development of a method for producing a sex resin sheet has been required.

As a result of diligent studies on the above problems, the present inventors cut out a resin sheet made of a thermosetting resin composition for semiconductor encapsulation to a mass value larger than a target mass value, and large pieces and small pieces having a predetermined shape. After die-cutting the individual pieces to an excess mass or more to make the resin sheet after die-cutting the individual pieces less than the target mass value, the resin sheets of the large piece and the small piece are adjusted by calculation to have the target mass. We have found that by adjusting to the value, it is possible to prevent unfilled and resin leakage from the molding mold when sealing a large-area, thin thermosetting resin sheet for encapsulating a semiconductor, and completed the present invention.

That is, the present invention is a method for producing a thermosetting resin sheet for semiconductor encapsulation.
(A) A step of cutting a thermosetting resin sheet into a predetermined shape.
(B) A step of die-cutting a resin sheet cut to a fixed size in the step (a) into a predetermined shape with a mass of more than 100% and 200% or less of the target mass.
(C) From the resin sheet die-cut in the step (b), a large piece of 5% by mass or more and 20% by mass or less and a small piece of 0.01% by mass or more and less than 5% by mass with respect to the mass of the resin sheet are each. Pieces of 0 or more and 1 or more and 10 or less in total are cut into individual pieces so that the mass of the resin sheet is 50% to 99% of the target mass, and each piece is separated from the resin sheet. The process of separating each piece and weighing the resin sheet after die cutting of each piece,
(D) In the step (c), the mass of the resin sheet after the individual piece is die-cut and the mass of each piece are calculated, and the total mass of the resin sheet mass after the individual piece die-cut and the mass of each piece is the said. Step to adjust so that it is 99% by mass or more and 101% by mass or less of the target mass,
It is a method for producing a thermosetting resin sheet for semiconductor encapsulation, which is characterized by having.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.
(1) Method for manufacturing thermosetting resin sheet for semiconductor encapsulation
(A) Fixed size cutting process

As a method for producing a thermosetting resin sheet for semiconductor encapsulation of the present invention, first, as shown in FIG. 1, the thermosetting resin sheet is cut into a predetermined shape. The shape can be selected from a circular shape, an elliptical shape, a polygonal shape having a quadrangle or more, or an indeterminate shape.

As the thermosetting resin sheet used in the present invention, it is preferable to use a thermosetting resin composition formed into a sheet by extrusion molding in advance, and in particular, the sheet is extruded through a T-die. It is preferable from the viewpoints of stability of width and thickness, ease of manufacture, and the like. The width of the resin sheet is preferably 190 mm or more, and particularly preferably 192 mm or more. If it is 190 mm or more, a resin sheet suitable for sealing a large-diameter wafer can be obtained. The thickness of the resin sheet is preferably 0.2 mm or more and 5 mm or less. Within this range, the handleability at the time of die cutting in the next step is excellent, and the die cutting property is also good, which is preferable. Further, since the space volume of the die-cut portion does not increase, molding voids are unlikely to be generated during molding, which is preferable.

Further, the resin sheet cut to a fixed size in this step has a mass exceeding 100% by mass of the target mass in consideration of being die-cut in the next step. Here, the "target mass" means a mass necessary and sufficient for sealing a substrate, a wafer, or the like to be sealed.

Further, the thermosetting resin sheet used in the present invention may be one in which at least one side is covered with a resin film in order to protect the surface and improve the handleability. Examples of the resin film include a polyethylene film, a polypropylene film, a polyethylene terephthalate film, a polytetrafluoroethylene film and the like.

As the thermosetting resin composition used in the present invention, a thermosetting resin mixed with an inorganic filler and other additives can be used. The composition will be described in detail below.

The thermosetting resin is not particularly limited as long as it is for encapsulating semiconductors and can be made into a sheet, but specifically, it is an epoxy resin, a silicone resin, an epoxy / silicone hybrid resin, a curable polyimide resin, or a maleimide resin. , Cyanate resin and the like. Of these, epoxy resins and silicone resins are preferably used. The thermosetting resin may be used alone or in combination of a plurality of resins.

<< Epoxy resin >>
The epoxy resin may contain two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy. Naphthalene skeleton-containing epoxy resin such as resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, bifunctional biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, dihydroanthracene Examples include type epoxy resins. Above all, from the viewpoint of dielectric properties and thermal expansion properties, it is preferable to use a naphthalene skeleton-containing epoxy resin or a biphenyl aralkyl type epoxy resin. One of these types may be used alone, or two or more types may be used in combination.

Further, a curing agent that reacts with the epoxy resin may be used, and the type thereof is not particularly limited. For example, a phenol-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, and a benzoxazine compound can be mentioned. These curing agents may be used alone or in combination of two or more, but a phenol resin is preferably used in order to ensure the reliability of the semiconductor device. As for the compounding ratio of the epoxy resin and the curing agent, the amount of the active group capable of reacting with the epoxy group of the curing agent is 1.0 equivalent, and the amount of the epoxy group in the epoxy resin is 0.5 to 2.0 equivalent. It is preferably 0.6 to 1.8, and more preferably 0.8 to 1.5. At this ratio, characteristics such as the glass transition temperature after curing are excellent.

Further, a curing accelerator may be added in order to enhance the reactivity between the epoxy resin and the curing agent. The curing accelerator is not particularly limited, and examples thereof include nitrogen-based curing accelerators such as amines and imidazoles, phosphorus-based curing accelerators such as quaternary phosphonium salts, organometallic salts, and derivatives thereof. ..

<< Silicone resin >>
Examples of the silicone resin include addition-curing silicone resin and condensation silicone resin. Examples of the addition-curable silicone resin include the following components (a) to (c).
(A) Organopolysiloxane represented by the following average composition formula (1) and having at least two or more alkenyl groups bonded to silicon atoms in one molecule.

（式中、Ｒ^１は独立に水酸基、炭素数１〜１０の脂肪族炭化水素基、炭素数５〜１０の脂環式炭化水素基、炭素数６〜１０の芳香族炭化水素基、及び炭素数２〜１０のアルケニル基から選ばれる基であり、ａ、ｂ、ｃ、ｄは、ａ≧０、ｂ≧０、ｃ≧０、ｄ≧０、ａ＋ｂ＋ｃ＋ｄ＝１を満足する数である。）
（ｂ）下記平均組成式（２）で示され、ケイ素原子に結合した水素原子を１分子中に少なくとも２個以上有するオルガノハイドロジェンポリシロキサン

(In the formula, R ¹ is independently a hydroxyl group, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, and carbon. It is a group selected from the alkenyl groups of the numbers 2 to 10, and a, b, c, and d are numbers satisfying a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, and a + b + c + d = 1.)
(B) Organohydrogenpolysiloxane represented by the following average composition formula (2) and having at least two or more hydrogen atoms bonded to silicon atoms in one molecule.

（式中、Ｒ^２は独立に水素原子、または水酸基、炭素数１〜１０の脂肪族炭化水素基、炭素数５〜１０の脂環式炭化水素基、炭素数６〜１０の芳香族炭化水素基から選ばれる基であり、ｅ、ｆ、ｇ、ｈは、ｅ≧０、ｆ≧０、ｇ≧０、ｈ≧０、ｅ＋ｆ＋ｇ＋ｈ＝１を満足する数である。）
（（ａ）成分と（ｂ）成分との配合比率は、（ａ）成分中のケイ素原子に結合したアルケニル基１モル当たり、（ｂ）成分中のケイ素原子に結合した水素原子の量が０．１〜５．０モルとなる量である）、及び
（ｃ）付加反応触媒
を含有したシリコーン樹脂が挙げられる。

(In the formula, R ² is an independently hydrogen atom or hydroxyl group, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, and an aromatic hydrocarbon having 6 to 10 carbon atoms. The groups are selected from the groups, and e, f, g, and h are numbers that satisfy e ≧ 0, f ≧ 0, g ≧ 0, h ≧ 0, and e + f + g + h = 1.)
The blending ratio of the component (a) and the component (b) is such that the amount of hydrogen atoms bonded to the silicon atom in the component (b) is 0 per mole of the alkenyl group bonded to the silicon atom in the component (a). The amount is 1 to 5.0 mol), and (c) a silicone resin containing an addition reaction catalyst.

Further, as the condensation type silicone resin, the following component (d),
(D) Organopolysiloxane represented by the following average composition formula (3) and having at least two or more condensation reactive groups in one molecule.

（式中、Ｒ^３は独立して水酸基、炭素数１〜６のアルコキシ基、炭素数１〜１０の脂肪族炭化水素基、炭素数５〜１０の脂環式炭化水素基、炭素数６〜１０の芳香族炭化水素基から選ばれる基であり、１分子中Ｒ^３の少なくとも２個以上は水酸基、または炭素数１〜６のアルコキシ基から選ばれる基であり、ｉ、ｊ、ｋ、ｌは、ｉ≧０、ｊ≧０、ｋ≧０、ｌ≧０、ｉ＋ｊ＋ｋ＋ｌ＝１を満足する数である。）
を含有したシリコーン樹脂が挙げられる。

(In the formula, R ³ is independently a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, and 6 to 10 carbon atoms. a group selected from 10 aromatic hydrocarbon group, at least two per molecule R ³ is a group selected hydroxyl group or an alkoxy group having 1 to 6 carbon atoms,, i, j, k, l Is a number that satisfies i ≧ 0, j ≧ 0, k ≧ 0, l ≧ 0, i + j + k + l = 1).
Examples thereof include silicone resins containing.

The component (d) is condensed and cured by heating alone, but a condensation catalyst may be added separately in order to accelerate the curing.

<< Curable polyimide resin, maleimide resin >>
Curable polyimide resins are classified according to the chemical properties of their reaction end groups. Among these, the use of maleimide resin is preferable from the viewpoint of curability, reliability and the like. The maleimide resin will be described below.

The maleimide resin is a compound containing two or more maleimide groups in one molecule, and may be any resin as long as it is a resin in which the maleimide groups react with each other and are cured by heating. Examples of the maleimide resin include N, N'-(4,4'-diphenylmethane) bismaleimide, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane and the like.

In addition, a reaction initiator may be contained in order to further accelerate curing. The reaction initiator is not limited, and examples thereof include peroxides. Further, a compound having a functional group capable of reacting a maleimide group may be contained as a curing agent. Examples of the curing agent include alicyclic maleimides, aromatic maleimides, unsaturated hydrocarbons, aromatic amines, aliphatic amines, alicyclic amines, acid anhydrides, isocyanates and the like. ..

<< Cyanate resin >>
The cyanate resin is not particularly limited as long as it has two or more cyanate groups in one molecule, but for example, a method such as reacting a cyanide cyanide compound with phenols or naphthols and heating if necessary. Can be used as obtained by prepolymerizing in.

Examples of the cyanate resin include novolak type cyanate resin, bisphenol type cyanate resin, naphthol aralkyl type cyanate resin, dicyclopentadiene type cyanate resin, biphenylalkyl type cyanate resin and the like. Of these, those having a small cyanate group equivalent have a small curing shrinkage, and a cured product having a low coefficient of thermal expansion and a high glass transition temperature can be obtained. One of these types may be used alone, or two or more types may be used in combination.

Further, a curing agent or a curing catalyst may be contained. The types of the curing agent and the curing catalyst are not particularly limited, and examples of the curing agent include phenolic curing agents and dihydroxynaphthalene compounds, and examples of the curing accelerator include primary amines and metal complexes.

<Inorganic filler>
The thermosetting resin composition for encapsulating a sheet-shaped semiconductor may further contain an inorganic filler. By optionally containing an appropriate inorganic filler, the low thermal expansion characteristics, high elastic modulus, heat resistance, flame retardancy and the like of the thermosetting resin composition for encapsulating a sheet-shaped semiconductor can be improved.

As the inorganic filler, one usually blended in a thermocurable resin composition such as an epoxy resin composition can be used, and is not particularly limited, but for example, silica, cristovaliteized silica, alumina, titanium oxide, mica, and the like. , Berilia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride , Calcined clay, talc, aluminum borate, silicon carbide and the like. Above all, the compounding of silica is preferable in order to obtain a low coefficient of thermal expansion, and the compounding of spherical silica is particularly preferable in order to obtain a high filling rate. These may be used alone or in combination of two or more.

There are no particular restrictions on the shape and particle size of the inorganic filler. The shape of the inorganic filler may be, for example, spherical or crushed, but as described above, it is preferable that the inorganic filler is spherical for high filling. The particle size of the inorganic filler can be, for example, 0.01 to 50 μm, preferably 0.01 to 20 μm, more preferably 0.1 to 15 μm, and even more preferably 0.1 to 10 μm. Here, the particle size refers to the average particle size, and can be 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 mixing ratio of the inorganic filler to the above-mentioned thermosetting resin is not particularly limited, but the fluidity, moldability, adhesiveness, toughness, heat resistance, and chemical resistance of the thermosetting resin composition for encapsulating sheet-shaped semiconductors are not particularly limited. From the viewpoint of the above, the total amount of the thermosetting resin components is preferably in the range of 1 to 1,000 parts by mass with respect to 100 parts by mass, and after curing while suppressing the thermal expansion of the thermosetting resin. From the viewpoint of maintaining toughness, it is more preferably 100 to 800 parts by mass.

<Other additives>
If necessary, not only the above-mentioned curing agents and curing accelerators, but also adhesive aids, silane coupling agents, titanate coupling agents, thermoplastic resins, pigments, mold release agents, resin particles, ion trap materials and flame retardants. Various additives such as can be blended. As the additive, a known additive can be used.

<< Adhesive aid >>
An adhesive aid (adhesive-imparting agent) can be added to impart adhesiveness to the thermosetting resin composition. Examples of the adhesion aid include a hydrogen atom (Si—H group) bonded to a silicon atom, an alkenyl group bonded to a silicon atom (for example, Si—CH = CH ₂ groups), and an alkoxysilyl group (for example, a tri) in one molecule. A silane containing a methoxysilyl group), an epoxy group (for example, a glycidoxypropyl group, a 3,4-epoxycyclohexylethyl group), an isocyanate group (for example, an organooxysilyl modified isocyanurate compound and a hydrolyzate condensate thereof) as a functional group. , Siloxane. The adhesive aid can be used alone or in combination of two or more.

<< Coupling agent >>
Silane coupling agent, titanate coupling agent, etc. in order to strengthen the bonding strength between the thermosetting resin composition and the inorganic filler and to improve the wettability of the thermosetting resin composition to the inorganic filler. Coupling agent can be added. Further, an inorganic filler in which the surface of the inorganic filler is previously treated with a coupling agent may be used.

Examples of the coupling agent include epoxy-functional alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Amino-functional alkoxysilanes such as N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; γ-mercaptopropyltri Used with silane coupling agents such as mercaptofunctional alkoxysilane such as methoxysilane, titanate coupling agents such as isopropyltriisostearoyl titanate, tetraoctylbis (ditridecylphosphite) titanate, and bis (dioctylpyrophosphate) oxyacetate titanate. Will be done. The amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

<< Thermoplastic resin >>
Thermoplastic resin may be added to improve the properties. Examples of the thermoplastic resin include fluororesin, polyphenylene ether resin, styrene-ethylene-butylene copolymer, cycloolefin polymer, acrylic block copolymer and the like, and any amount of these can be added.

<< Colorant >>
A colorant may be added for the purpose of coloring. The colorant is not particularly limited, and known pigments or dyes can be used alone or in combination of two or more. In particular, a black colorant is preferable from the viewpoint of improving the appearance and laser marking property.

Examples of black colorants include carbon black (furness black, channel black, acetylene black, thermal black, lamp black, etc.), graphite (graphite), copper oxide, manganese dioxide, and azo pigments (azomethine black, etc.). Aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, composite oxide black dye, anthraquinone organic Examples thereof include black pigments, and among them, carbon black is preferably used.

The colorant is preferably contained in an amount of 0.1 to 30 parts by mass, and particularly preferably 1 to 15 parts by mass, in 100 parts by mass of the thermosetting resin composition.

<< Release agent >>
A mold release agent can be blended not only to improve the mold release property during molding but also to prevent overload during resin production. The release agent is not particularly limited, but in the case of a thermosetting epoxy resin composition, natural wax such as carnauba wax and rice wax, acid wax, polyethylene wax, and synthetic wax such as fatty acid ester are used. Is preferable.

(B) Die-cutting step Then, as shown in FIG. 2, it is necessary and sufficient to seal the resin sheet cut to a fixed size in the step (a) with a target mass (a substrate, a wafer, etc. to be sealed). The die is cut into a predetermined shape with a mass of more than 100% and 200% or less, preferably 105 to 180% of the mass). Examples of the predetermined shape include a shape selected from a circular shape, an elliptical shape, a polygonal shape of a quadrangle or more, or an indefinite shape, as in the case of the sizing step. A circular shape is preferable, and a square shape is preferable when sealing a square panel. Further, the die cutting method is not particularly limited, and a general die cutting machine can be used.

(C) Individual piece die-cutting step Next, as shown in FIG. 3, a large piece of 5% by mass or more and 20% by mass or less from the resin sheet die-cut in the step (b) with respect to the mass of the resin sheet. And 0 or more small pieces of 0.01% by mass or more and less than 5% by mass, and 1 or more and 10 or less pieces in total so that the mass of the resin sheet is 50% to 99% of the target mass. A step is performed in which each piece is separated from the resin sheet, and each piece and the resin sheet after the piece is die-cut are weighed.

(D) Mass Adjustment Step In the step (c), after weighing each piece and the resin sheet after die cutting, as shown in FIG. 4, a large piece and / Alternatively, a step of adjusting to the target mass is performed by adding small pieces.
The amount of individual pieces for mass adjustment is adjusted by the following formula.
X: target mass W of the resin sheet: resin sheet weight after singulation die-cut W _L: large pieces total mass W _S: Sum mass 0.99X ≦ pieces _{(W + W L + W S} ) ≦ 1.01X

By going through the steps (a) to (d) above, when the semiconductor element mounting substrate is sealed with a large-area, thin thermosetting resin sheet for semiconductor encapsulation, the resin of the unfilled molding mold. It is possible to prevent leakage.

(E) Support Substrate Laminating Step The thermosetting resin sheet for semiconductor encapsulation obtained in the present invention may be further laminated with the supporting substrate. By laminating the thermosetting resin sheet for semiconductor encapsulation with the support substrate, a encapsulation substrate with less warpage can be obtained. Examples of support substrates include inorganic substrates such as ceramic substrates and silicon wafers, metal substrates such as copper and aluminum substrates whose surface has been insulated, epoxy resin substrates, BT resin substrates, polyimide resin substrates, and even FRP substrates. An organic resin substrate such as the above can be mentioned.

Examples of the method for laminating the support substrate include vacuum laminating with a laminator and vacuum pressure crimping on a press machine.

(2) How to use the thermosetting resin sheet for semiconductor encapsulation The thermosetting resin sheet for semiconductor encapsulation manufactured by the manufacturing method shown in the present invention is the amount of resin required to encapsulate the target substrate ( Since the error is within 1% with respect to the target mass), when the semiconductor element is sealed using a large-area, thin thermosetting resin sheet for semiconductor encapsulation, the resin from unfilled or molded mold is used. Leakage can be prevented. As a specific sealing method, as shown in FIG. 5, the thermosetting resin sheet for semiconductor sealing of the present invention is laminated on a substrate on which a semiconductor element is placed, and compression molding using a compression molding machine is performed. A method of pressure molding using a vacuum press machine and further laminating molding using a laminator is preferably used. At this time, the pressure may be reduced for the purpose of removing voids. In addition, the semiconductor element can be sealed by placing a resin sheet on the substrate on which the semiconductor element is mounted and allowing the sheet to follow the substrate while melting the sheet. At this time, pressurization and / or depressurization is performed. It doesn't matter. According to such a method for sealing a semiconductor device, the thermosetting resin sheet for sealing a semiconductor obtained in the present invention is used to prevent unfilling or resin leakage from a molding die to seal a semiconductor element. can do.

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

<Preparation of sealing resin composition>
Cresol Novolac type epoxy resin (trade name: EPICLON-N655, manufactured by DIC Co., Ltd.) 40 parts by mass, crystalline bisphenol A type epoxy resin (trade name: YL-6810, manufactured by Mitsubishi Chemical Co., Ltd.) 12 parts by mass, phenol Novolac type curing agent (trade name: BRG-555, manufactured by Aika Kogyo Co., Ltd.) 30 parts by mass, spherical silica with an average particle size of 13 μm (trade name: RS-8225H / 53C, manufactured by Ryumori Co., Ltd.) 770 parts by mass , Imidazole-based curing accelerator (trade name: 1B2PZ, manufactured by Shikoku Kasei Co., Ltd.) 0.2 parts by mass, epoxy-based silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 1.0 Mass parts, carnauba wax (trade name: TOWAX-131, Toa Kasei Co., Ltd.) 1.0 part, black pigment (trade name: Mitsubishi Carbon Black 3230MJ, Mitsubishi Chemical Co., Ltd. 2.0 parts by mass) with a high-speed mixer After sufficiently dry-blending, a sheet-shaped thermosetting resin was prepared by heating, melt-kneading, and extruding using a twin-screw extruder equipped with a T-die at the tip, and the sheet was cut to a fixed size. The obtained sheet had a width of 300 mm. The thickness was 0.3 mm, and the length was cut every 500 mm.

<Die-cutting, weight adjustment process, molding using sheet>
(Example 1)
The sheet-shaped thermosetting resin composition cut to a fixed size was punched out using a punching device to obtain a circular die-cut resin sheet having a diameter of 290 mm. Its weight was 39.8 g. On the other hand, the required molding volume was 300 mm in diameter and 0.25 mm in thickness, and the amount of resin (target mass) required when using this resin sheet was calculated to be 35.5 g. Next, one large circular piece sheet having a diameter of 90 mm and one small circular piece sheet having a diameter of 33 mm are further punched from the circular die-cut resin sheet, and the die-cut pieces and the resin sheet after the piece-cutting are performed. The mass was calculated, and the total mass was adjusted to 35.5 g. When this sheet was molded on a Si wafer having a diameter of 300 mm with a compression molding machine as shown in FIG. 5, it could be molded without resin leakage or unfilling.

(Comparative Example 1)
The mass was adjusted to 36.0 g by punching out only one circular sheet having a diameter of 90 mm from the circular die-cut resin sheet. When this sheet was molded on a Si wafer having a diameter of 300 mm with a compression molding machine, a resin leak occurred.

(Comparative Example 2)
The mass was adjusted to 31.7 g by punching two circular large piece sheets having a diameter of 90 mm and one circular small piece sheet having a diameter of 33 mm from the circular die-cut resin sheet. When this sheet was molded on a Si wafer having a diameter of 300 mm with a compression molding machine, unfilling occurred.

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 effect and effect is the present invention. Is included in the technical scope of.

Claims (6)

A method for manufacturing a thermosetting resin sheet for semiconductor encapsulation.
(A) A step of cutting a thermosetting resin sheet into a predetermined shape.
(B) A step of die-cutting a resin sheet cut to a fixed size in the step (a) into a predetermined shape with a mass of more than 100% and 200% or less of the target mass.
(C) From the resin sheet die-cut in the step (b), a large piece of 5% by mass or more and 20% by mass or less and a small piece of 0.01% by mass or more and less than 5% by mass with respect to the mass of the resin sheet are each. Pieces of 0 or more and 1 or more and 10 or less in total are cut into individual pieces so that the mass of the resin sheet is 50% to 99% of the target mass, and each piece is separated from the resin sheet. The process of separating each piece and weighing the resin sheet after die cutting of each piece,
(D) In the step (c), the mass of the resin sheet after the individual piece is die-cut and the mass of each piece are calculated, and the total mass of the resin sheet mass after the individual piece die-cut and the mass of each piece is the said. Step to adjust so that it is 99% by mass or more and 101% by mass or less of the target mass,
A method for producing a thermosetting resin sheet for semiconductor encapsulation. (E) The method for producing a thermosetting resin sheet for semiconductor encapsulation according to claim 1, further comprising (e) a step of laminating the resin sheet with a support substrate. The semiconductor encapsulation according to claim 1 or 2, wherein the thermosetting resin sheet used in the step (a) is prepared by having a step of molding the thermosetting resin by extrusion molding. A method for manufacturing a thermosetting resin sheet for use. The thermosetting resin for semiconductor encapsulation according to any one of claims 1 to 3, wherein the width of the thermosetting resin sheet used in the step (a) is 190 mm or more. Sheet manufacturing method. The semiconductor encapsulation according to any one of claims 1 to 4, wherein the thickness of the thermosetting resin sheet used in the step (a) is 0.2 mm or more and 5 mm or less. A method for manufacturing a thermosetting resin sheet. By superimposing a thermosetting resin sheet for semiconductor encapsulation manufactured by the manufacturing method according to any one of claims 1 to 5 on a substrate on which a semiconductor element is placed and pressure molding the semiconductor element. A method for sealing a semiconductor device, which comprises sealing.

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