JPWO2019189541A1 - Resin sheet, how to use the resin sheet, and how to manufacture a cured encapsulant with a cured resin layer - Google Patents

Abstract

A resin sheet used for producing a cured encapsulant, which can produce a cured encapsulant with a cured resin film having a flat surface while suppressing warpage with improved productivity, and is a polymer component. It has a thermosetting resin layer formed from a thermosetting resin composition containing (A) and a thermosetting component (B), and an object to be sealed is placed on the surface of the thermosetting resin layer. The object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are coated with a sealing material, the sealing material is heat-cured, and the object to be sealed is included. A resin sheet used for manufacturing a cured encapsulant, which is a cured encapsulant.

Description

The present invention relates to a resin sheet, a method of using the resin sheet, and a method of manufacturing a cured encapsulant with a cured resin layer using the resin sheet.

In recent years, with the miniaturization and high functionality of electronic devices, further miniaturization, high functionality, and improvement of reliability are required for semiconductor packages.
Wafer level packaging (WLP) technology, which is one of the technologies that can meet such demands, forms an external electrode or the like on the chip circuit forming surface before being separated by dicing, and finally the chip. It is a technology to realize a surface mountable chip scale package (CSP) that can be miniaturized to the same scale as a semiconductor chip by dicing a package containing the above.

WLP is divided into Fan-In type and Fan-Out type.
In the Fan-Out type WLP, the semiconductor chip to be sealed is covered with a sealing material so as to have a region larger than the size of the semiconductor chip to form a semiconductor chip encapsulant, and then re-applied. The wiring layer and the external electrode are formed not only on the circuit surface of the semiconductor chip but also on the surface region of the encapsulant.

For example, in Patent Document 1, a plurality of semiconductor chips separated from a semiconductor wafer are surrounded by a molding member which is a sealing resin to form an expansion wafer, leaving the circuit forming surface thereof, and the semiconductor is formed. A method for manufacturing a semiconductor package formed by extending a rewiring pattern in a region outside the chip is described.
In the manufacturing method described in Patent Document 1, the silicon wafer is attached to a wafer mount tape for dicing and used in the dicing step. After that, it is replaced with a wafer mount tape for expansion, and is subjected to a tape expanding step in which the wafer mount tape (supporting tape) is spread to increase the distance between a plurality of silicon chips.

International Publication No. 2010/058646

By the way, in the production of a Fan-Out type WLP as described in Patent Document 1, a semiconductor chip to be sealed is coated with a sealing material, and the sealing material is thermoset by heating. It is common to have a step of sealing to form a cured sealant.
However, when the cured encapsulant obtained by heat-curing the encapsulant is separated from an adhesive tape such as a wafer mount tape fixed to the support, the cured encapsulant after separation is thermally shrunk. Warpage may occur.
A cured encapsulant whose surface is not flat due to warpage tends to have adverse effects such as easy cracking when the cured encapsulant is ground in the next step, and the cured encapsulant is hardened and sealed. When the body is transported by the device, a problem is likely to occur when the cured sealed body is delivered by the arm.

Further, a resin film may be further provided on one surface of the cured encapsulant to form a cured encapsulant with a resin film.
In order to manufacture such a cured encapsulant with a resin film, usually, a separately prepared resin film forming sheet is attached to one surface of the formed cured encapsulant, and the resin film forming sheet is cured. It is necessary to go through the process of forming a resin film.
In addition, as described above, the cured encapsulant tends to warp during manufacturing, so that the warp of the cured encapsulant reduces workability when the resin film forming sheet is attached and cures. There is also concern about a decrease in the adhesion between the resin film and the cured sealant.
Further, in the obtained cured sealant with a resin film, the warp may be further increased, which may cause various harmful effects in the next step.

The present invention provides a resin sheet used for producing a cured encapsulant, which can produce a cured encapsulant with a cured resin film having a flat surface while suppressing warpage with improved productivity. The purpose is.

The present inventors put a resin sheet having a thermosetting resin layer formed from a thermosetting resin composition containing a polymerizable component and a thermosetting component on the surface of the thermosetting resin layer to be sealed. It has been found that the above-mentioned problems can be solved by placing it, coating it with a sealing material, and curing it to obtain a cured sealing body containing an object to be sealed.

That is, the present invention relates to the following [1] to [9].
[1] It has a thermosetting resin layer formed from a thermosetting resin composition containing a polymerizable component (A) and a thermosetting component (B), and has a thermosetting resin layer.
An object to be sealed is placed on the surface of the thermosetting resin layer, and the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are covered with a sealing material. A resin sheet used for producing a cured encapsulant, which is obtained by thermosetting the encapsulant to obtain a cured encapsulant containing the encapsulant.
[2] The resin sheet according to the above [1], wherein when the sealing material is cured, the thermosetting resin layer is also cured to form a cured resin layer.
[3] The resin sheet according to the above [1] or [2], wherein the content of the colorant in the thermosetting resin composition is less than 8% by mass.
[4] The storage elastic modulus E'at 23 ° C. of the cured resin layer obtained by thermosetting the thermosetting resin layer is 1.0 × 10 ^{7 to} 1.0 × 10 ¹³ Pa. The resin sheet according to any one of [3].
[5] The resin sheet according to any one of the above [1] to [4], wherein the thickness of the thermosetting resin layer is 1 to 500 μm.
[6] The method for using the resin sheet according to any one of the above [1] to [5].
An object to be sealed is placed on the surface of the thermosetting resin layer.
The object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are coated with a sealing material.
The encapsulant is thermoset to obtain a cured encapsulant containing the encapsulant.
How to use the resin sheet.
[7] When the encapsulant is thermally cured, the thermosetting resin layer is also thermosetting to form a cured resin layer to form a cured encapsulant with a thermosetting resin layer. [6] How to use the resin sheet described in.
[8] A method for producing a cured encapsulant with a cured resin layer using the resin sheet according to any one of the above [1] to [5], wherein the following steps (i) to (iii) are used. A method for producing a cured encapsulant with a cured resin layer.
Step (i): A step of placing an object to be sealed on a part of the surface of the thermosetting resin layer of the resin sheet.
Step (ii): A step of coating the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed with a sealing material.
Step (iii): The encapsulant is heat-cured to form a cured encapsulant containing the object to be sealed, and the thermosetting resin layer is also thermoset to form a cured resin layer. A step of obtaining a cured encapsulant with a cured resin layer.

By using the resin sheet of the present invention for producing a cured encapsulant, a cured encapsulant having a flat surface by suppressing warpage can be produced with improved productivity.

It is sectional drawing which shows the structure of the resin sheet of one aspect of this invention. It is sectional drawing which showed the process of manufacturing the cured encapsulation body with a cured resin layer using the resin sheet 1d shown in FIG. 1 (d).

As used herein, the term "active ingredient" refers to a component contained in a target composition excluding a diluting solvent.
In the present specification, the mass average molecular weight (Mw) is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method, and specifically, a value measured based on the method described in Examples. Is.
In the present specification, for example, "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are also used.
In the present specification, the lower limit value and the upper limit value described stepwise for a preferable numerical range (for example, a range such as content) can be independently combined. For example, from the description of "preferably 10 to 90, more preferably 30 to 60", the "preferable lower limit value (10)" and the "more preferable upper limit value (60)" are combined to obtain "10 to 60". You can also do it.

[Construction of resin sheet]
The resin sheet of the present invention has a thermosetting resin layer formed from a thermosetting resin composition containing a polymerizable component (A) and a thermosetting component (B).
The resin sheet according to one aspect of the present invention may be a single-layered sheet composed of only a thermosetting resin layer, but has a multi-layer structure having a thermosetting resin layer and a layer other than the thermosetting resin layer. Sheet may be used.

FIG. 1 is a schematic cross-sectional view of the resin sheet showing the structure of the resin sheet according to one aspect of the present invention.
Examples of the resin sheet according to one aspect of the present invention include a resin sheet 1a having a base material 20 and a thermosetting resin layer 10 as shown in FIG. 1A. By using a resin sheet having a base material as in the resin sheet 1a, self-supporting property can be improved and handleability can be improved.

Further, in order to improve the adhesion between the base material 20 and the thermosetting resin layer 10, the base material 20, the pressure-sensitive adhesive layer 30, and the thermosetting resin are as shown in the resin sheet 1b shown in FIG. 1 (b). A resin sheet in which the layers 10 are laminated in this order may be used.
The resin sheet 1b may be configured by further laminating a release material on the adhesive surface of the pressure-sensitive adhesive layer 30.

Further, as a resin sheet of another aspect of the present invention, there is a resin sheet 1c having a thermosetting resin layer 10 and an adhesive layer 30 as shown in FIG. 1 (c).
By having the pressure-sensitive adhesive layer 30 like the resin sheet 1c, the resin sheet can be sufficiently fixed to the support or the like, and the workability in the sealing step can be improved.

As shown in the resin sheet 1d shown in FIG. 1D, the resin sheet is obtained by laminating the second pressure-sensitive adhesive layer 32, the base material 20, the first pressure-sensitive adhesive layer 31, and the thermosetting resin layer 10 in this order. May be good.
By configuring the resin sheet 1d or the like, the resin sheet can be sufficiently fixed to the support or the like, and the adhesion between the base material 20 and the thermosetting resin layer 10 can be improved. Workability in the sealing process can be improved.
The resin sheet 1d may be configured by further laminating a release material on the adhesive surface of the second pressure-sensitive adhesive layer 32.

From the viewpoint of protecting the surface of the thermosetting resin layer, the resin sheet according to one aspect of the present invention may be configured to further have a release material on the surface of the thermosetting resin layer.
For example, the resin sheet according to one aspect of the present invention may have a structure in which a thermosetting resin layer is sandwiched between two release materials, and the thermosetting resin sheets 1a, 1b, 1c, and 1d shown in FIG. A release material may be further laminated on the exposed surface of the sex resin layer 10.
The release material is provided to protect the surface of the thermosetting resin layer, and is removed when the resin sheet is used.

[Use of resin sheet]
In the resin sheet of the present invention, an object to be sealed is placed on the surface of the thermosetting resin layer, and the surface of the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed. Is used for producing a cured encapsulant, which is obtained by coating with a sealing material and thermosetting the encapsulant to obtain a cured encapsulant containing the object to be sealed.
A specific embodiment of the production of the cured encapsulant using the resin sheet of the present invention will be described later.

For example, after placing the object to be sealed on the adhesive surface of an adhesive sheet such as a general wafer mount tape as used in the manufacturing method described in Patent Document 1, the object to be sealed and its peripheral portion. Consider the case where the adhesive surface of the above is coated with a sealing material and the sealing material is thermoset to produce a cured sealing body.
When the encapsulant is thermoset, stress acts to shrink the encapsulant, but the stress of the encapsulant is suppressed because the adhesive sheet is fixed to the support.
However, the cured seal obtained by separating from the support and the pressure-sensitive adhesive sheet is difficult to suppress the stress to shrink. In the cured sealed body after separation, the amount of the sealing material abundant differs between the surface side on the side where the object to be sealed exists and the surface side opposite to the surface side, so that the shrinkage stress tends to be different. The difference in shrinkage stress causes warping of the cured encapsulant.
Further, from the viewpoint of productivity, the cured encapsulant after heating is generally separated from the support and the pressure-sensitive adhesive sheet in a state of being heated to some extent. Therefore, even after the separation, the encapsulant is cured and shrinks due to natural cooling, so that the cured encapsulant is more likely to warp.

On the other hand, when the resin sheet of the present invention is used, a cured sealed body in which warpage is effectively suppressed can be obtained for the following reasons.
That is, when the object to be sealed is placed on the surface of the thermosetting resin layer of the resin sheet of the present invention, coated with the sealing material, and the sealing material is heat-cured, the thermosetting resin layer is also formed at the same time. Thermosetting. At this time, since the abundance of the sealing material is small and the thermosetting resin layer is provided on the surface side on the side where the sealing object is considered to have a small shrinkage stress due to the curing of the sealing material. , Shrinkage stress due to thermosetting of the thermosetting resin layer works.
As a result, it is considered that the difference in shrinkage stress between the two surfaces of the cured encapsulant can be reduced, and the cured encapsulant with the warp effectively suppressed can be obtained.

In addition, the thermosetting resin layer that contributes to the suppression of warpage of the cured encapsulant can be made into a cured resin layer by thermosetting. This cured resin layer has a function as a protective film.
That is, by using the resin sheet of the present invention and undergoing the above-mentioned sealing step, a cured resin layer can be formed on one surface of the cured encapsulant at the same time, so that the cured resin layer is formed. This process can be omitted, which also contributes to the improvement of productivity.

Hereinafter, each layer of the resin sheet according to one aspect of the present invention will be described.

<Thermosetting resin layer>
The resin sheet of the present invention has a thermosetting resin layer formed from a thermosetting resin composition containing a polymerizable component (A) and a thermosetting component (B).
The thermosetting resin layer is thermally cured together with the encapsulant when the encapsulant is thermally cured to reduce the difference in shrinkage stress between the two surfaces of the cured encapsulant, and the obtained cured encapsulant is obtained. Contributes to the suppression of warpage that may occur in.
Further, the thermosetting resin layer is thermally cured to become a cured resin layer. The cured resin layer is formed on one surface of the obtained cured encapsulant and has a function as a protective film.

The storage elastic modulus E'at 23 ° C. of the cured resin layer obtained by thermosetting the thermosetting resin layer is determined from the viewpoint of forming a cured encapsulant having a flat surface by suppressing warpage as a resin sheet that can be produced. It is preferably 1.0 × 10 ⁷ Pa or more, more preferably 1.0 × 10 ⁸ Pa or more, further preferably 1.0 × 10 ⁹ Pa or more, and even more preferably 5.0 × 10 ⁹ Pa or more. Further, it is preferably 1.0 × 10 ¹³ Pa or less, more preferably 1.0 × 10 ¹² Pa or less, further preferably 5.0 × 10 ¹¹ Pa or less, still more preferably 1.0 × 10 ¹¹ Pa or less. is there.
In this specification, the storage elastic modulus E'means a value measured based on the method described in Examples.

Since the object to be sealed is placed on the surface of the thermosetting resin layer, the surface of the thermosetting resin layer may have adhesiveness from the viewpoint of improving the adhesion with the object to be sealed. preferable.
In addition, the surface of the thermosetting resin layer on the side opposite to the side on which the object to be sealed is placed is also adherent to the support and the like, and when the resin sheet is provided with the base material, the base is used. From the viewpoint of improving the adhesion with the material, it is preferable to have adhesiveness.

The adhesive strength on the surface of the thermosetting resin layer at room temperature (23 ° C.) is preferably 0.01 to 5 N / 25 mm, more preferably 0.05 to 4 N / 25 mm, still more preferably 0.1 to 3 N /. It is 25 mm.
In this specification, the adhesive strength on the surface of the thermosetting resin layer means a value measured by the method described in Examples.

In the resin sheet of one aspect of the present invention, the thickness of the thermosetting resin layer is preferably 1 to 500 μm, more preferably 5 to 300 μm, still more preferably 10 to 200 μm, still more preferably 15 to 100 μm.

In the present invention, the thermosetting resin layer is a layer formed from a thermosetting resin composition containing a polymer component (A) and a thermosetting component (B).
However, the thermosetting resin composition may further contain one or more selected from the colorant (C), the coupling agent (D), and the inorganic filler (E), but suppresses warpage. It is preferable to contain at least an inorganic filler (E) from the viewpoint of making a curable encapsulant having a flat surface into a manufacturable resin sheet.

(Polymer component (A))
The polymer component (A) contained in the thermosetting resin composition means a compound having a mass average molecular weight of 20,000 or more and having at least one repeating unit.
By containing the polymerizable component (A), the thermosetting resin composition imparts flexibility and film-forming property to the formed thermosetting resin layer, and can improve the sheet property retention property. it can.
The mass average molecular weight (Mw) of the polymer component (A) is preferably 20,000 or more, more preferably 20,000 to 3 million, still more preferably 50,000 to 2 million, still more preferably 100,000 to 1.5 million, and more. More preferably, it is 200,000 to 1,000,000.

The content of the polymer component (A) is preferably 5 to 50% by mass, more preferably 8 to 40% by mass, still more preferably, based on the total amount (100% by mass) of the active ingredient of the thermosetting resin composition. Is 10 to 30% by mass.

Examples of the polymer component (A) include acrylic polymers, polyesters, phenoxy resins, polycarbonates, polyethers, polyurethanes, polysiloxanes, rubber-based polymers and the like.
These polymer components (A) may be used alone or in combination of two or more.
In the present specification, the acrylic polymer having an epoxy group and the phenoxy resin having an epoxy group have thermosetting properties, but their mass average molecular weight is 20,000 or more, and at least one of them is used. If it is a compound having the repeating unit of, it is included in the concept of the polymer component (A).

Among these, the polymer component (A) preferably contains an acrylic polymer (A1).
The content ratio of the acrylic polymer (A1) in the polymer component (A) is preferably 60 to 60 with respect to the total amount (100% by mass) of the polymer component (A) contained in the thermosetting resin composition. It is 100% by mass, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

(Acrylic polymer (A1))
The mass average molecular weight (Mw) of the acrylic polymer (A1) is preferably 20,000 to 3 million, more preferably 10 from the viewpoint of imparting flexibility and film-forming property to the thermosetting resin layer to be formed. It is 10,000 to 1.5 million, more preferably 150,000 to 1.2 million, and even more preferably 250,000 to 1 million.

The glass transition temperature (Tg) of the acrylic polymer (A1) is determined from the viewpoint of imparting good adhesiveness to the surface of the thermosetting resin layer to be formed, and the cured resin layer produced by using a resin sheet. From the viewpoint of improving the reliability of the cured encapsulant, the temperature is preferably -60 to 50 ° C, more preferably -50 to 30 ° C, further preferably -40 to 10 ° C, still more preferably -5 to 5 ° C. is there.

Examples of the acrylic polymer (A1) include polymers containing an alkyl (meth) acrylate as a main component, and specifically, an alkyl (meth) acrylate (a1') having an alkyl group having 1 to 18 carbon atoms. An acrylic polymer containing a structural unit (a1) derived from (hereinafter, also referred to as "monomer (a1')") is preferable, and a functional group-containing monomer (a2') (hereinafter, "monomer (a1')" is preferable together with the structural unit (a1). An acrylic copolymer containing a structural unit (a2) derived from "a2')" is more preferable.
The acrylic polymer (A1) may be used alone or in combination of two or more.
When the acrylic polymer (A1) is a copolymer, the form of the copolymer may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer. Good.

The number of carbon atoms of the alkyl group of the monomer (a1') is preferably 1 to 18, and more preferably 1 to 12 from the viewpoint of imparting flexibility and film-forming property to the thermosetting resin layer to be formed. , More preferably 1-8. The alkyl group may be a straight chain alkyl group or a branched chain alkyl group.
These monomers (a1') may be used alone or in combination of two or more.

From the viewpoint of improving the reliability of the cured encapsulant with a cured resin layer produced by using the resin sheet, the monomer (a1') contains an alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms. It is preferable, and it is more preferable to contain methyl (meth) acrylate.
From the above viewpoint, the content of the structural unit (a11) derived from the alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms is based on the total structural unit (100% by mass) of the acrylic polymer (A1). It is preferably 1 to 80% by mass, more preferably 5 to 80% by mass, and further preferably 10 to 80% by mass.

Further, from the viewpoint of increasing the gloss value of the cured resin layer formed by thermosetting the formed thermosetting resin layer and improving the suitability for laser marking, the monomer (a1') contains an alkyl group having 4 or more carbon atoms. It is preferable to contain an alkyl (meth) acrylate having an alkyl (meth) acrylate, more preferably to contain an alkyl (meth) acrylate having an alkyl group having 4 to 6 carbon atoms, and further preferably to contain a butyl (meth) acrylate.
From the above viewpoint, the content of the structural unit (a12) derived from the alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms (preferably 4 to 6, more preferably 4) is the acrylic polymer (A1). It is preferably 1 to 70% by mass, more preferably 5 to 65% by mass, and further preferably 10 to 60% by mass with respect to all the constituent units (100% by mass).

The content of the structural unit (a1) is preferably 50% by mass or more, more preferably 50 to 99% by mass, still more preferably 55, based on the total structural unit (100% by mass) of the acrylic polymer (A1). It is ~ 90% by mass, more preferably 60 to 90% by mass.

The monomer (a2') is preferably one or more selected from the hydroxy group-containing monomer and the epoxy group-containing monomer.
The monomer (a2') may be used alone or in combination of two or more.

Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl ( Hydroxyalkyl (meth) acrylates such as meta) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol can be mentioned.
Among these, the hydroxy group-containing monomer is preferably hydroxyalkyl (meth) acrylate, and more preferably 2-hydroxyethyl (meth) acrylate.

Examples of the epoxy-containing monomer include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth) acrylate. Epoxy group-containing (meth) acrylates such as glycidyl crotonate, allyl glycidyl ether and the like.
Among these, the epoxy-containing monomer is preferably an epoxy group-containing (meth) acrylate, and more preferably glycidyl (meth) acrylate.

The content of the structural unit (a2) is preferably 1 to 50% by mass, more preferably 5 to 45% by mass, still more preferably 5 to 45% by mass, based on the total structural unit (100% by mass) of the acrylic polymer (A1). It is 10 to 40% by mass, more preferably 10 to 30% by mass.

The acrylic polymer (A1) may have a structural unit derived from a monomer other than the above-mentioned structural units (a1) and (a2) as long as the effect of the present invention is not impaired.
Examples of other monomers include vinyl acetate, styrene, ethylene, α-olefin and the like.

<Thermosetting component (B)>
The thermosetting component (B) plays a role of thermosetting the formed thermosetting resin layer into a hard curable resin layer, and is a compound having a mass average molecular weight of less than 20,000.
The mass average molecular weight (Mw) of the curable component (B) is preferably 10,000 or less, more preferably 100 to 10,000.

The thermosetting component (B) is an epoxy compound (B1) which is a compound having an epoxy group and a thermosetting component (B1) from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface by suppressing warpage. It is preferable to contain the agent (B2), and it is more preferable to further contain the curing accelerator (B3) together with the epoxy compound (B1) and the thermosetting agent (B2).

Examples of the epoxy compound (B1) include polyfunctional epoxy resin, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolac epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, and bisphenol A type epoxy resin. , Bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, and the like, and examples thereof include epoxy compounds having two or more functions in the molecule and having a mass average molecular weight of less than 20,000.
The epoxy compound (B1) may be used alone or in combination of two or more.

The content of the epoxy compound (B1) is the polymer component (A) contained in the thermosetting resin composition from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface by suppressing warpage. ) 100 parts by mass, preferably 1 to 500 parts by mass, more preferably 3 to 300 parts by mass, still more preferably 10 to 150 parts by mass, still more preferably 20 to 120 parts by mass.

The thermosetting agent (B2) functions as a curing agent for the epoxy compound (B1).
The thermosetting agent (B2) is preferably a compound having two or more functional groups capable of reacting with an epoxy group in one molecule.
Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, an acid anhydride and the like. Among these, phenolic hydroxyl groups, amino groups, or acid anhydrides are preferable from the viewpoint of producing an adhesive laminate capable of producing a cured encapsulant having a cured resin film having a flat surface while suppressing warpage. A phenolic hydroxyl group or an amino group is more preferable, and an amino group is further preferable.

Examples of the phenol-based heat-curing agent having a phenol group include polyfunctional phenol resins, biphenols, novolak-type phenol resins, dicyclopentadiene-based phenol resins, zylock-type phenol resins, and aralkylphenol resins.
Examples of the amine-based thermosetting agent having an amino group include dicyandiamide (DICY) and the like.
These thermosetting agents (B2) may be used alone or in combination of two or more.

The content of the thermosetting agent (B2) is 100 mass by mass of the epoxy compound (B1) from the viewpoint of suppressing warpage and making a cured encapsulant with a cured resin film having a flat surface into an adhesive laminate capable of being produced. It is preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass with respect to parts.

The curing accelerator (B3) is a compound having a function of increasing the rate of thermosetting when the thermosetting resin layer to be formed is thermally cured.
Examples of the curing accelerator (B3) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole, and the like. Imidazoles such as 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole; tributylphosphine, diphenylphosphine, triphenylphosphine and the like. Organic phosphins; tetraphenylborone salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate can be mentioned.
These curing accelerators (B3) may be used alone or in combination of two or more.

The content of the curing accelerator (B3) is the same as that of the epoxy compound (B1) and the thermosetting agent (B2) from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface by suppressing warpage. It is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 6 parts by mass, and further preferably 0.3 to 4 parts by mass with respect to 100 parts by mass of the total amount.

<Colorant (C)>
The thermosetting resin composition used in one aspect of the present invention may further contain a colorant (C).
When the thermosetting resin layer formed from the thermosetting resin composition containing the colorant (C) is heat-cured to form a cured resin layer, the cured resin layer emits infrared rays and the like generated from surrounding devices. By shielding, it is possible to prevent malfunction of the object to be sealed (semiconductor chip, etc.).

Organic or inorganic pigments and dyes can be used as the colorant (C).
As the dye, for example, any dye such as an acid dye, a reactive dye, a direct dye, a disperse dye, and a cationic dye can be used.
The pigment is not particularly limited, and a known pigment can be appropriately selected and used.
Among these, black pigments are preferable from the viewpoint of having good shielding properties of electromagnetic waves and infrared rays and further improving the distinguishability by the laser marking method.
Examples of the black pigment include carbon black, iron oxide, manganese dioxide, aniline black, activated carbon and the like, but carbon black is preferable from the viewpoint of improving the reliability of the semiconductor chip.
These colorants (C) may be used alone or in combination of two or more.

However, in the thermosetting resin composition used in one aspect of the present invention, the content of the colorant (C) is 8% by mass with respect to the total amount (100% by mass) of the active ingredient of the thermosetting resin composition. It is preferably less than.
When the content of the colorant (C) is less than 8% by mass, the resin sheet can be obtained so that the presence or absence of cracks on the surface of the chip and the chipping can be visually confirmed.
From the above viewpoint, in the thermosetting resin composition used in one aspect of the present invention, the content of the colorant (C) is preferably based on the total amount (100% by mass) of the active components of the thermosetting resin composition. Is less than 5% by mass, more preferably less than 2% by mass, still more preferably less than 1% by mass, still more preferably less than 0.5% by mass.

Further, from the viewpoint of exhibiting a shielding effect such as infrared rays on the cured resin layer formed by thermosetting the formed thermosetting resin layer, the content of the colorant (C) is the active component of the thermosetting resin composition. With respect to the total amount (100% by mass) of, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more, still more preferably 0.15% by mass or more. Is.

<Coupling agent (D)>
The thermosetting resin composition used in one aspect of the present invention may further contain a coupling agent (D).
The thermosetting resin layer formed from the thermosetting resin composition containing the coupling agent (D) can improve the adhesiveness with the object to be sealed when the object to be sealed is placed. Further, the cured resin layer formed by thermosetting the thermosetting resin layer can improve the water resistance without impairing the heat resistance.

The coupling agent (D) is preferably a compound that reacts with the functional groups of the polymerizable component (A) and the thermosetting component (B), and specifically, a silane coupling agent is preferable.
Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2- (3,4-epoxycyclohexyl). Ethyltrimethoxysilane, 3- (methacryloxypropyl) trimethoxysilane, 3-aminopropyltrimethoxysilane, N-6- (aminoethyl) -3-aminopropyltrimethoxysilane, N-6- (aminoethyl)- 3-Aminopropylmethyldiethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis (3-tri) Ethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane and the like can be mentioned.
These coupling agents (D) may be used alone or in combination of two or more.

The molecular weight of the coupling agent (D) is preferably 100 to 15,000, more preferably 125 to 10,000, more preferably 150 to 5,000, still more preferably 175 to 3,000, still more preferably 200. ~ 2,000.

The content of the coupling agent (D) is preferably 0.01 to 10% by mass, more preferably 0.05 to 7% by mass, based on the total amount (100% by mass) of the active ingredient of the thermosetting resin composition. %, More preferably 0.10 to 4% by mass, still more preferably 0.15 to 2% by mass.

<Inorganic filler (E)>
The thermosetting resin composition used in one aspect of the present invention further contains an inorganic filler (E) from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface by suppressing warpage. It is preferable to do so.
By forming a thermosetting resin layer formed from a thermosetting resin composition containing an inorganic filler (E), when the encapsulant is thermally cured, the shrinkage stress between the two surfaces of the cured encapsulant is reduced. The degree of thermosetting of the thermosetting resin layer can be adjusted so that the difference becomes small. As a result, it becomes possible to produce a cured encapsulant having a flat surface while suppressing warpage.
Further, the coefficient of thermal expansion of the cured resin layer formed by heat-curing the formed thermosetting resin layer can be adjusted within an appropriate range, and the reliability of the object to be sealed can be improved. It is also possible to reduce the hygroscopicity of the cured resin layer.

Examples of the inorganic filler (E) include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride and the like, spherical beads, single crystal fibers, glass fibers and the like. Examples include non-thermally expandable particles.
These inorganic fillers (E) may be used alone or in combination of two or more.
Among these, silica or alumina is preferable from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface while suppressing warpage.

The average particle size of the inorganic filler (E) is preferably 0.3 to 50 μm, more preferably 0, from the viewpoint of improving the gloss value of the cured resin film formed by heat-curing the formed thermosetting resin layer. .5 to 30 μm, more preferably 0.7 to 10 μm.

The content of the inorganic filler (E) is the total amount (100) of the active components of the thermosetting resin composition from the viewpoint of forming a resin sheet capable of producing a cured encapsulant having a flat surface by suppressing warpage. With respect to (% by mass), it is preferably 25 to 80% by mass, more preferably 30 to 70% by mass, still more preferably 40 to 65% by mass, and even more preferably 45 to 60% by mass.

<Other additives>
The thermosetting resin composition used in one aspect of the present invention further comprises the above-mentioned polymerizable component (A), thermosetting component (B), colorant (C), as long as the effects of the present invention are not impaired. Other additives other than the coupling agent (D) and the inorganic filler (E) (hereinafter referred to as components (A) to (E)) may be contained.
Examples of additives other than the components (A) to (E) include cross-linking agents, leveling agents, plasticizers, antistatic agents, antioxidants, ion scavengers, gettering agents, chain transfer agents and the like. Can be mentioned.
The total content of the other additives other than the components (A) to (E) is preferably 0 to 20% by mass, based on the total amount (100% by mass) of the active ingredient of the thermosetting resin composition. It is preferably 0 to 10% by mass, more preferably 0 to 5% by mass.

<Base material>
The resin sheet of one aspect of the present invention may have a base material together with a thermosetting resin layer.
The thickness of the base material used in one embodiment of the present invention is preferably 10 to 500 μm, more preferably 15 to 300 μm, and even more preferably 20 to 200 μm.

Examples of the base material used in one aspect of the present invention include a sheet-like material composed of one or more selected from paper materials, resins, metals and the like, and a resin base material containing a resin is preferable.
Examples of the paper material include thin-leaf paper, medium-quality paper, high-quality paper, impregnated paper, coated paper, art paper, parchment paper, and glassin paper.
Examples of the resin constituting the resin base material include polyolefin resins such as polyethylene and polypropylene; vinyl-based resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer. Resins: Polyester terephthalates, polybutylene terephthalates, polyethylene naphthalates and other polyester resins; polystyrene; acrylonitrile-butadiene-styrene copolymers; cellulose triacetate; polycarbonates; polyurethanes, acrylic-modified polyurethanes and other urethane resins; polymethylpentene; polysulfones Polyether ether ketone; polyether sulfone; polyphenylene sulfide; polyimide-based resin such as polyetherimide and polyimide; polyamide-based resin; acrylic resin; fluorine-based resin and the like.
Examples of the metal include aluminum, tin, chromium, titanium and the like.

In addition to the above-mentioned resin, the resin base material may contain additives for the base material such as an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an anti-blocking agent, and a colorant. ..

The base material used in the present invention may be one made of one kind of material or one made of two or more kinds of materials.
Examples of the base material formed from two or more kinds of materials include a paper material laminated with a thermoplastic resin such as polyethylene, a base material having a metal film formed on the surface of a resin base material containing the resin, and the like. ..
As a method for forming the metal layer, for example, a method of vapor-depositing the metal by a PVD method such as vacuum deposition, sputtering, or ion plating, or a method of attaching a metal foil made of the metal by a general adhesive is used. The method of doing this can be mentioned.

Further, when the thermosetting resin layer is laminated on the base material as in the resin sheet 1a shown in FIG. 1A, the viewpoint of improving the adhesion between the base material and the thermosetting resin layer is improved. Therefore, the surface of the base material may be subjected to surface treatment, easy adhesion treatment, or primer treatment by an oxidation method, an unevenness method, or the like.

<Adhesive layer>
The resin sheet of one aspect of the present invention may further have an adhesive layer.
In one aspect of the present invention, the adhesive strength of the pressure-sensitive adhesive layer is preferably 0.10 to 10.0 N / 25 mm, more preferably 0.15 to 8.0 N / 25 mm, still more preferably 0.25 to 6.0 N. / 25 mm, more preferably 0.25 to 4.0 N / 25 mm.
In this specification, the adhesive strength means a value measured by the method described in Examples.
Further, for example, when the resin sheet 1d shown in FIG. 1D has a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, the adhesive strength of each of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is high. It is preferably within the above range.

In one aspect of the present invention, the thickness of the pressure-sensitive adhesive layer is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 5 to 25 μm.

The pressure-sensitive adhesive layer can be formed from a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive resin.
The adhesive resin used in one embodiment of the present invention may be a polymer having adhesiveness by itself and having a mass average molecular weight (Mw) of 10,000 or more. Examples of the adhesive resin include rubber resins such as acrylic resins, urethane resins, and polyisobutylene resins, polyester resins, olefin resins, silicone resins, and polyvinyl ether resins.
These adhesive resins may be used alone or in combination of two or more.

The mass average molecular weight (Mw) of the adhesive resin used in one embodiment of the present invention is preferably 10,000 to 2 million, more preferably 20,000 to 1.5 million, and further preferably 30,000 to 30,000 from the viewpoint of improving the adhesive strength. It is one million.

Further, the pressure-sensitive adhesive composition may further contain an additive for a pressure-sensitive adhesive, depending on the type of the pressure-sensitive adhesive resin used.
Examples of such adhesive additives include cross-linking agents, tackifiers, polymerizable compounds, polymerization initiators, antioxidants, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, and the like. Examples thereof include a reaction accelerator (catalyst), an ultraviolet absorber, and an antioxidant.

The content of the adhesive resin is preferably 35% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, based on the total amount (100% by mass) of the active ingredient of the pressure-sensitive adhesive composition. More preferably, it is 70% by mass or more.

The pressure-sensitive adhesive layer contained in the resin sheets having the configurations of the resin sheets 1b, 1c, and 1d of FIG. 1 is an energy ray-curable pressure-sensitive adhesive composition containing an energy ray-curable pressure-sensitive adhesive resin and a photopolymerization initiator. It may be a layer formed from.
By forming the pressure-sensitive adhesive layer formed from such an energy ray-curable pressure-sensitive adhesive composition, a cured resin layer and a cured sealant are formed, and then the adhesive strength is reduced by irradiating with energy rays. , The pressure-sensitive adhesive layer and the cured resin layer can be easily separated.
Examples of the energy ray include ultraviolet rays and electron beams, but ultraviolet rays are preferable.

The energy ray-curable pressure-sensitive adhesive composition is a composition containing an energy-ray-curable pressure-sensitive adhesive resin in which a polymerizable functional group such as a (meth) acryloyl group or a vinyl group is introduced into the side chain of the above-mentioned pressure-sensitive adhesive resin. It may be a composition containing a monomer or an oligomer having a polymerizable functional group.
In addition, it is preferable that these compositions further contain a photopolymerization initiator.

Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzylphenyl sulfate, tetramethylthium monosulfide, and azobisisobutyrol. Examples thereof include nitrile, dibenzyl, diacetyl, 8-chloranthraquinone and the like.
These photopolymerization initiators may be used alone or in combination of two or more.
The content of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0, with respect to 100 parts by mass of the energy ray-curable adhesive resin or 100 parts by mass of the monomer or oligomer having a polymerizable functional group. It is .03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass.

[How to use the adhesive laminate]
By using the resin sheet of the present invention for producing a cured encapsulant, it is possible to produce a cured encapsulant having a flat surface while suppressing warpage with improved productivity.
Therefore, the present invention can also provide a method of using the resin sheet shown in the following [I].
[I] The method for using the resin sheet of the present invention described above.
An object to be sealed is placed on the surface of the thermosetting resin layer.
The object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are coated with a sealing material.
A method of using a resin sheet, wherein the sealing material is thermally cured to obtain a cured sealing body containing the sealing object.

In the method of use described in [I] above, when the encapsulant is heat-cured, the thermosetting resin layer is also heat-cured to form a cured resin layer, and the material is cured with a thermosetting resin layer. It is preferably a sealed body.
By using the above-mentioned resin sheet of the present invention, it is possible to produce a cured encapsulant having a flat surface by suppressing warpage (cured encapsulant with a cured resin film) with improved productivity.
In the usage method described in the above [I], the preferable configuration of the resin sheet is as described above, and the types of the sealing material, the coating method of the sealing material, various conditions of thermosetting, etc. are as follows. It is as described in the section of "Manufacturing method of hardened sealant with hardened resin layer" shown in.

[Manufacturing method of cured encapsulant with cured resin film]
Examples of the method for producing a cured encapsulant with a cured resin film using the resin sheet of the present invention include methods having the following steps (i) to (iii).
Step (i): A step of placing an object to be sealed on a part of the surface of the thermosetting resin layer of the resin sheet.
Step (ii): A step of coating the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed with a sealing material.
Step (iii): The encapsulant is heat-cured to form a cured encapsulant containing the object to be sealed, and the thermosetting resin layer is also thermoset to form a cured resin layer. A step of obtaining a cured encapsulant with a cured resin layer.
FIG. 2 is a schematic cross-sectional view showing a process of manufacturing a cured encapsulant with a cured resin layer using the resin sheet 1d shown in FIG. 1 (d). Hereinafter, each of the above steps will be described with reference to FIG. 2 as appropriate.

<Step (i)>
The step (i) is a step of placing the object to be sealed on a part of the surface of the thermosetting resin layer of the resin sheet.
In FIG. 2A, the adhesive surface of the second adhesive layer 32 of the resin sheet 1d is attached to the support 100, and the object to be sealed 60 is placed on a part of the surface of the thermosetting resin layer 10. Shows the state of
Although FIG. 2 (a) shows an example in which the resin sheet 1d shown in FIG. 1 (d) is used, FIG. 2 (a) also shows a case where the resin sheet of the present invention having another configuration is used. ), The support, the resin sheet, and the object to be sealed are laminated or placed in this order.

The step (i) is preferably performed at a temperature at which the thermosetting resin layer is not thermally cured, and the specific temperature condition of the step (i) is usually 10 to 80 ° C.

When a resin sheet having a second adhesive layer on the support side is used as in the resin sheet 1d of FIG. 1D, the entire surface of the adhesive surface of the second adhesive layer of the resin sheet and the support are formed. It is preferable that it is attached.
Therefore, the support is preferably plate-shaped.
Further, in this case, the area between the adhesive surface of the second pressure-sensitive adhesive layer and the surface of the support on the side to be attached is preferably equal to or larger than the area of the pressure-sensitive adhesive surface of the second pressure-sensitive adhesive layer, as shown in FIG. ..

The material constituting the support depends on the type of the object to be sealed, the type of the sealing material used in the step (ii), etc., and takes into consideration the required characteristics such as mechanical strength and heat resistance. It is selected as appropriate.
Specific materials constituting the support include metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; epoxy resins, ABS resins, acrylic resins, engineering plastics, super engineering plastics, and polyimide resins. Resin materials such as polyamideimide resin; composite materials such as glass epoxy resin are mentioned, and among these, SUS, glass, silicon wafer and the like are preferable.
Examples of engineering plastics include nylon, polycarbonate (PC), polyethylene terephthalate (PET), and the like.
Examples of super engineering plastics include polyphenylene sulfide (PPS), polyethersulfone (PES), and polyetheretherketone (PEEK).

The thickness of the support is appropriately selected depending on the type of the object to be sealed, the type of the sealing material used in the step (ii), and the like, but is preferably 20 μm or more and 50 mm or less, more preferably. It is 60 μm or more and 20 mm or less.

On the other hand, examples of objects to be sealed placed on a part of the surface of the thermosetting resin layer include semiconductor chips, semiconductor wafers, compound semiconductors, semiconductor packages, electronic components, sapphire substrates, displays, and panel substrates. And so on.

For example, when the object to be sealed is a semiconductor chip, the semiconductor chip with a cured resin layer can be manufactured by using the resin sheet of the present invention.
Conventionally known semiconductor chips can be used, and integrated circuits composed of circuit elements such as transistors, resistors, and capacitors are formed on the circuit surface thereof.
The semiconductor chip is preferably placed so that the back surface opposite to the circuit surface is covered with the surface of the thermosetting resin layer. In this case, the circuit surface of the semiconductor chip is exposed after mounting.
A known device such as a flip chip bonder or a die bonder can be used for mounting the semiconductor chip.
The layout of the arrangement of the semiconductor chips, the number of arrangements, and the like may be appropriately determined according to the form of the target package, the number of production, and the like.

Here, like FOWLP, FOPLP, etc., the semiconductor chip is covered with a sealing material in a region larger than the chip size to form a rewiring layer not only on the circuit surface of the semiconductor chip but also on the surface region of the sealing material. It is preferable that it is applied to the package to be used.
Therefore, the semiconductor chip is placed on a part of the surface of the thermosetting resin layer, and a plurality of semiconductor chips are placed on the surface in a state of being aligned at a certain interval. It is preferable, and it is more preferable that the plurality of semiconductor chips are placed on the surface in a state of being arranged in a matrix of a plurality of rows and a plurality of columns at regular intervals.
The distance between the semiconductor chips may be appropriately determined according to the form of the target package and the like.

<Process (ii)>
Step (ii) is a step of coating the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed with a sealing material.
The sealing material covers the entire exposed surface of the object to be sealed, and is also filled in the gaps between the plurality of semiconductor chips.
FIG. 2B shows a state in which the object to be sealed 60 and the surface of the thermosetting resin layer 10 are completely covered with the sealing material 70.
In this step, as shown in FIG. 2B, it may be coated with a sealing material 70 so as to cover the entire surface of the thermosetting resin layer 10, and it becomes a peripheral portion of the sealing object 60. A part of the surface of the thermosetting resin layer 10 may be coated with the sealing material 70.

The sealing material has a function of protecting the object to be sealed and the elements associated therewith from the external environment.
The encapsulant used in the production method of the present invention is a thermosetting encapsulant containing a thermosetting resin.
Further, the encapsulant may be a solid such as granules, pellets or a film at room temperature, or may be a liquid in the form of a composition, but from the viewpoint of workability, the encapsulant may be a film. A sealing resin film which is a sealing material of the above is preferable.

As the coating method, it can be appropriately selected and applied according to the type of sealing material from the methods applied in the conventional sealing process. For example, a roll laminating method, a vacuum pressing method, or a vacuum laminating method can be applied. , Spin coating method, die coating method, transfer molding method, compression molding method and the like can be applied.

<Process (iii)>
In step (iii), the encapsulant is thermally cured to form a cured encapsulant containing an object to be sealed, and the thermosetting resin layer is also thermoset to form a cured resin layer. This is a step of obtaining a hardened sealant.
The step (iii) may be carried out separately from the previous step (ii), or may be carried out at the same time.
For example, when the encapsulant is heated in the previous step (ii), the encapsulant may be thermoset as it is by performing the main step by the heating.

As shown in FIG. 2C, in this step, the encapsulant is heat-cured to form a cured encapsulant 71 containing the object to be encapsulated 60, and the thermosetting resin layer is also thermoset. The cured resin layer 11 is formed.
In this step, since the thermosetting resin layer is thermally cured together with the encapsulant, the difference in shrinkage stress between the two surfaces of the cured encapsulant can be reduced, and the warp generated in the cured encapsulant is effective. It is thought that it can be suppressed.

The temperature condition in step (iii) may be equal to or higher than the temperature at which the encapsulant and the thermosetting resin layer are thermally cured, depending on the type of encapsulant and the types of components constituting the thermosetting resin layer. , But it is usually 120 to 220 ° C.

After that, as shown in FIG. 2D, the cured resin layer 11 is separated from the cured resin layer formed by thermosetting the thermosetting resin layer at the interface between the first pressure-sensitive adhesive layer 31 and the cured resin layer 11. A cured encapsulant 80 with a cured resin layer can be obtained, which has a cured encapsulant 71 including an object 60 to be sealed.
Here, when the first pressure-sensitive adhesive layer 31 is a layer formed from an energy ray-curable pressure-sensitive adhesive composition, it can be easily separated by irradiating it with energy rays.

If a general pressure-sensitive adhesive sheet is used after separation from the support, the cured seal may warp. However, since the cured encapsulant with a cured resin layer obtained by using the resin sheet of the present invention has a cured resin layer, warpage that may occur in the cured encapsulant can be effectively suppressed.

The cured encapsulant with a cured resin layer thus obtained is then subjected to a step of grinding the cured encapsulant until the circuit surface of the semiconductor chip is exposed and rewiring the circuit surface. , The process of forming the external electrode pad and connecting the external electrode pad and the external terminal electrode may be performed.
Further, after the external terminal electrode is connected to the cured encapsulant, the cured encapsulant can be separated into individual pieces to manufacture a semiconductor device.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples. The physical property values in the following production examples and examples are values measured by the following methods.

<Mass average molecular weight (Mw)>
It was measured under the following conditions using a gel permeation chromatograph device (manufactured by Tosoh Corporation, product name "HLC-8020"), and the value measured in terms of standard polystyrene was used.
(Measurement condition)
-Column: "TSK guard volume HXL-L""TSK gel G2500HXL""TSK gel G2000HXL""TSK gel G1000HXL" (all manufactured by Tosoh Corporation) are connected in sequence.-Column temperature: 40 ° C.
-Development solvent: tetrahydrofuran-Flow velocity: 1.0 mL / min

<Measurement of thickness of each layer>
Constant pressure thickness measuring instrument manufactured by Teclock Co., Ltd. (Model number: "PG-02J", Standard: JIS
Measured using K6783, Z1702, Z1709).

<Storage modulus E'of the cured resin layer after thermosetting of the thermosetting resin layer>
After laminating the thermosetting resin layer to a thickness of 200 μm, the thermosetting resin layer is placed in an oven in an air atmosphere and heated at 130 ° C. for 2 hours to heat-cure the thermosetting resin layer having a thickness of 200 μm. It was a cured resin layer.
Using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, product name "DMAQ800"), the test start temperature is 0 ° C, the test end temperature is 300 ° C, the temperature rise rate is 3 ° C / min, the frequency is 11 Hz, and the amplitude is 20 μm. The storage elastic modulus E'of the formed cured resin layer at 23 ° C. was measured under the conditions of.

<Measurement of adhesive strength>
A PET film having a thickness of 50 μm (manufactured by Toyobo Co., Ltd., product name “Cosmo Shine A4100”) was laminated on the surface of the pressure-sensitive adhesive layer or the thermosetting resin layer formed on the release film.
Then, the release film is removed, and the surface of the exposed pressure-sensitive adhesive layer or thermosetting resin layer is attached to a stainless steel plate (SUS304 No. 360 polishing) as an adherend, and the temperature is 23 ° C. and 50% RH (relative humidity). ), After allowing to stand for 24 hours, the adhesive strength at 23 ° C. was measured at a tensile speed of 300 mm / min by a 180 ° peeling method based on JIS Z0237: 2000 under the same environment.

The release material used in the following production examples is as follows.
<Release material>
-Heavy release film: manufactured by Lintec Corporation, product name "SP-PET382150", polyethylene terephthalate (PET) film provided with a release agent layer formed from a silicone-based release agent on one side, thickness: 38 μm.
-Light release film: manufactured by Lintec Corporation, product name "SP-PET381031", PET film provided with a release agent layer formed from a silicone-based release agent on one side, thickness: 38 μm.

Manufacturing example 1
(1) Preparation of thermosetting resin composition Each component of the following types and blending amounts (both are "active ingredient ratios") is blended, further diluted with methyl ethyl ketone, uniformly stirred, and the solid content concentration (1). A solution of a thermosetting resin composition having an active ingredient concentration of 61% by mass was prepared.
Acrylic polymer: Acrylic obtained by copolymerizing 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate. A system polymer (mass average molecular weight: 400,000, glass transition temperature: -1 ° C.), corresponding to the above component (A1).
-Epoxy compound (1): compounding amount = 10.4 parts by mass Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER828", epoxy equivalent = 184 to 194 g / eq), corresponding to the above component (B1) ..
-Epoxy compound (2): compounding amount = 5.2 parts by mass Dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, product name "Epiclon HP-7200HH", epoxy equivalent = 255-260 g / eq), the above component (B1) ) Equivalent. -Epoxy compound (3): compounding amount = 1.7 parts by mass Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER1055", epoxy equivalent = 800 to 900 g / eq), equivalent to the above component (B1) ..
-Thermosetting agent: compounding amount = 0.42 parts by mass dicyandiamide (manufactured by ADEKA, product name "ADEKA Hardener EH-3636AS", amount of active hydrogen = 21 g / eq), corresponding to the above component (B2).
-Curing accelerator: compounding amount = 0.42 parts by mass 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., product name "Curesol 2PHZ"), equivalent to the above component (B3).
Colorant: Blending amount = 0.20 parts by mass Carbon black (manufactured by Mitsubishi Chemical Corporation, product name "# MA650", average particle size = 28 nm), equivalent to the above component (C).
-Silane coupling agent: compounding amount = 0.09 parts by mass 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM403"), molecular weight = 236.64, to the above component (D) Equivalent.
-Inorganic filler: compounding amount = 55.5 parts by mass Silica filler (manufactured by Admatex, product name "SC2050MA", average particle size = 0.5 μm), corresponding to the above component (E).

(2) Formation of Thermosetting Resin Layer A coating film is formed by applying the solution of the thermosetting resin composition prepared in (1) above on the peeling surface of the light release film, and the coating film is formed. It was dried at 120 ° C. for 2 minutes to form a thermosetting resin layer having a thickness of 25 μm.
The adhesive strength of the formed thermosetting resin layer was 0.5 N / 25 mm.
Also, the storage modulus E thermosetting resin layer at 23 ° C. of the cured resin layer formed by thermally curing 'was 6.5 × 10 9 ^Pa.

Manufacturing example 2
(1) Preparation of Adhesive Composition The following isocyanate-based cross-linking agent (i) 5.0 parts by mass (solid content ratio) is added to 100 parts by mass of the solid content of the following acrylic copolymer (i), which is an adhesive resin. Was mixed, diluted with toluene, and stirred uniformly to prepare a pressure-sensitive adhesive composition having a solid content concentration (active ingredient concentration) of 25% by mass.
Acrylic copolymer (i): It has a structural unit derived from a raw material monomer composed of 2-ethylhexyl acrylate (2EHA) / 2-hydroxyethyl acrylate (HEA) = 80.0 / 20.0 (mass ratio). An acrylic copolymer having a mass average molecular weight of 600,000.
-Isocyanate cross-linking agent (i): manufactured by Tosoh Corporation, product name "Coronate L", solid content concentration: 75% by mass.

(2) Formation of Adhesive Layer The pressure-sensitive adhesive composition prepared in (1) above is applied to the surface of the release agent layer of the light release film to form a coating film, and the coating film is applied at 100 ° C. for 60 seconds. It was dried to form a first pressure-sensitive adhesive layer having a thickness of 5 μm.
Further, a second pressure-sensitive adhesive layer having a thickness of 5 μm was formed on the surface of the release agent layer of the heavy-release film in the same manner.
The adhesive strength of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer measured based on the above method was 0.3 N / 25 mm.

Example 1
A first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer formed in Production Example 2 on both sides of a 50 μm-thick polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name “Cosmo Shine A4100”) as a base material. Were pasted respectively.
Then, the light release film laminated on the first pressure-sensitive adhesive layer is removed, and the exposed pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer and the surface of the thermosetting resin layer formed in Production Example 1 are bonded together. , A resin sheet in which a heavy-release film / second pressure-sensitive adhesive layer / base material / first pressure-sensitive adhesive layer / thermosetting resin layer / light-release film was laminated in this order was obtained.

Example 2
A cured encapsulant with a cured resin layer was produced by the following procedure.
(1) Placement of Semiconductor Chip The heavy-release film of the resin sheet produced in Example 1 was removed, and the exposed adhesive surface of the second adhesive layer was attached to a support (glass).
Then, the light release film of the resin sheet was also removed, and nine semiconductor chips (each chip size was 6.4 mm × 6.4 mm, and the chip thickness was 200 μm) were placed on the surface of the exposed thermosetting resin layer. (# 2000)) was placed at a necessary interval so that the back surface of each semiconductor chip opposite to the circuit surface was in contact with the front surface.

(2) Formation of Cured Encapsulant and Cured Resin Layer The nine semiconductor chips and the surface of the thermosetting resin layer at least in the peripheral portion of the semiconductor chip are thermosetting seals which are encapsulants. It was coated with a waterproof resin film, and the sealing resin film was thermosetting using a vacuum heating and pressurizing laminator (“7024HP5” manufactured by ROHM and HAAS) to prepare a cured sealing body.
The sealing conditions are as follows.
・ Preheating temperature: 100 ° C for both table and diaphragm
・ Evacuation: 60 seconds ・ Dynamic press mode: 30 seconds ・ Static press mode: 10 seconds ・ Sealing temperature: 180 ° C
Sealing time: 60 minutes Along with the thermosetting of the sealing resin film, the thermosetting resin layer was also cured in the above environment to obtain a cured resin layer.

(3) Separation of the cured resin layer and the first pressure-sensitive adhesive layer After the above (2), the cured resin layer obtained by heat-curing the thermosetting resin layer and the first pressure-sensitive adhesive layer are separated at the interface. A cured sealant with a cured resin layer was obtained.
The obtained cured encapsulant with a cured resin layer was cooled to room temperature (25 ° C.), but no warpage was observed.

The resin sheet of the present invention is a cured encapsulant containing an object to be sealed, such as a semiconductor chip, placed on the surface of a thermosetting resin layer, covered with a sealing material, and cured. It can be used for the production of. Then, a cured encapsulant with a cured resin film, which suppresses warpage and has a flat surface, can be produced with improved productivity.

1a, 1b, 1c, 1d Resin sheet 10 Thermosetting resin layer 11 Curing resin layer 20 Base material 30, 31, 32 Adhesive layer 60 Encapsulating object 70 Encapsulant 71 Curing encapsulant 80 Curing with curable resin layer Encapsulant 100 Support

Claims (8)

It has a thermosetting resin layer formed from a thermosetting resin composition containing a polymerizable component (A) and a thermosetting component (B), and has a thermosetting resin layer.
An object to be sealed is placed on the surface of the thermosetting resin layer, and the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are covered with a sealing material. A resin sheet used for producing a cured encapsulant, which is obtained by thermosetting the encapsulant to obtain a cured encapsulant containing the encapsulant. The resin sheet according to claim 1, wherein when the sealing material is cured, the thermosetting resin layer is also cured to form a cured resin layer. The resin sheet according to claim 1 or 2, wherein the content of the colorant in the thermosetting resin composition is less than 8% by mass. Any of claims 1 to 3, wherein the cured resin layer obtained by thermosetting the thermosetting resin layer has a storage elastic modulus ^{E'at 23 ° C. of 1.0 × 10 7 to} 1.0 × 10 ^{13 Pa.} The resin sheet described in item 1. The resin sheet according to any one of claims 1 to 4, wherein the thermosetting resin layer has a thickness of 1 to 500 μm. The method for using the resin sheet according to any one of claims 1 to 5.
An object to be sealed is placed on the surface of the thermosetting resin layer.
The object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed are coated with a sealing material.
A method of using a resin sheet, wherein the sealing material is thermally cured to obtain a cured sealing body containing the sealing object. The resin according to claim 6, wherein when the encapsulant is thermally cured, the thermosetting resin layer is also thermosetting to form a cured resin layer to form a cured encapsulant with a thermosetting resin layer. How to use the sheet. A method for producing a cured encapsulant with a cured resin layer using the resin sheet according to any one of claims 1 to 5, wherein the cured resin layer has the following steps (i) to (iii). Manufacturing method of hardened sealant with resin.
Step (i): A step of placing an object to be sealed on a part of the surface of the thermosetting resin layer of the resin sheet.
Step (ii): A step of coating the object to be sealed and the surface of the thermosetting resin layer at least in the peripheral portion of the object to be sealed with a sealing material.
Step (iii): The encapsulant is heat-cured to form a cured encapsulant containing the object to be sealed, and the thermosetting resin layer is also thermoset to form a cured resin layer. A step of obtaining a cured encapsulant with a cured resin layer.

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