JPWO2019098329A1 - Thermosetting resin film and first protective film forming sheet - Google Patents

Abstract

A thermosetting resin film (12) for forming a first protective film on the surface of a semiconductor wafer by affixing it to a surface having bumps and heat-curing the film. A thermosetting resin film (12) in which the minimum value of shear viscosity at 90 ° C. to 130 ° C. is 500 Pa · s or more when the temperature of (12) is raised at 10 ° C./min. A first protective film forming sheet (1) provided with a first support sheet (101) and a thermosetting resin film (12) on one surface (101a) of the first support sheet (101).

Description

The present invention includes a thermosetting resin film for forming a first protective film on the surface of a semiconductor wafer by affixing it to a surface having bumps and thermosetting the surface, and the thermosetting resin film. 1 Regarding a protective film forming sheet.
The present application claims priority based on Japanese Patent Application No. 2017-221986 filed in Japan on November 17, 2017, the contents of which are incorporated herein by reference.

Conventionally, when a multi-pin LSI package used for MPU, gate array, etc. is mounted on a printed wiring board, as a semiconductor chip, a convex electrode made of eutectic solder, high temperature solder, gold, etc. is attached to the connection pad portion (hereinafter referred to as a convex electrode). , Referred to as "bumps" in the present specification), and by the so-called face-down method, these bumps are brought into face-to-face contact with the corresponding terminal portions on the chip mounting substrate to melt / diffuse. A flip-chip mounting method for joining has been adopted.

The semiconductor chip used in this mounting method is, for example, a semiconductor wafer having bumps formed on the circuit surface, and the surface opposite to the circuit surface (in other words, the bump forming surface) is ground or diced to be individualized. Obtained by In the process of obtaining such a semiconductor chip, usually, a curable resin film is attached to the bump forming surface and the bump forming surface is cured for the purpose of protecting the bump forming surface and the bump of the semiconductor wafer. A protective film (hereinafter, may be referred to as a "first protective film" in the present specification) is formed.

The curable resin film is usually attached to the bump forming surface of the semiconductor wafer in a state of being softened by heating. By doing so, the upper portion including the crown of the bump penetrates the curable resin film and protrudes from the curable resin film. On the other hand, the curable resin film spreads between the bumps so as to cover the bumps of the semiconductor wafer, adheres to the bump forming surface, and covers the surface of the bumps, particularly the surface in the vicinity of the bump forming surface, and the bumps. Embed. After that, the curable resin film is further cured to cover the bump-forming surface of the semiconductor wafer and the surface of the portion near the bump-forming surface of the bump to become a protective film that protects these regions. Further, the semiconductor wafer is solidified into a semiconductor chip and finally has a protective film on the bump forming surface (in the present specification, it may be referred to as a "semiconductor chip with a protective film"). It becomes.

Such a semiconductor chip with a protective film is mounted on a substrate to form a semiconductor package, and the semiconductor package is used to form a target semiconductor device. In order for the semiconductor package and the semiconductor device to function normally, it is necessary that the electric connection between the bump of the semiconductor chip with the protective film and the circuit on the substrate is not obstructed. However, if the curable resin film is not properly attached to the bump forming surface of the semiconductor wafer, the bumps may not protrude sufficiently from the curable resin film, or the curable resin film may be formed on the crown of the bump. Some will remain. The curable resin film remaining on the crown of the bump in this way is cured in the same manner as in the case of the curable resin film in other regions, and is a cured product having the same composition as the protective film (in the present specification, It may be referred to as "protective film residue"). Then, since the crown of the bump is an electrical connection region between the bump and the circuit on the substrate, when the amount of the protective film residue is large, the bump of the semiconductor chip with the protective film and the circuit on the substrate The electrical connection of, is obstructed.
That is, before mounting the semiconductor chip with the protective film on the substrate, there is no protective film residue or the amount of the protective film residue is small at the crown of the bump of the semiconductor chip with the protective film. Is required.

As described above, as the protective film forming sheet capable of forming the protective film without leaving the curable resin film on the bump upper part, the curable resin film is stored at the temperature at which the sheet is attached to the semiconductor wafer. The elastic modulus between the shear modulus and the storage shear modulus of the buffer layer is defined in a specific range (see Patent Document 1).

JP-A-2015-206006

All of the protective film forming sheets disclosed in Patent Document 1 define the physical properties of the curable resin film at the temperature at which the sheet is attached to the semiconductor wafer.

However, when a thermosetting resin film is thermosetting to form a protective film on the bumped surface of a semiconductor wafer, it is temporarily melted and liquefied to cause cissing, resulting in poor protective film formation. Sometimes.

Therefore, the present invention is a thermosetting resin film for forming a first protective film on the surface by attaching it to a surface of a semiconductor wafer having bumps and heat-curing the film. It is an object of the present invention to provide a thermosetting resin film capable of suppressing cissing on the surface of a semiconductor wafer when it is attached to a surface of a semiconductor wafer having bumps and heat-cured. Another object of the present invention is to provide a first protective film forming sheet provided with this thermosetting resin film.

In order to solve the above problems, the present invention is a thermosetting resin film for forming a first protective film on the surface of a semiconductor wafer by attaching it to a surface having bumps and heat-curing it. Provided is a thermosetting resin film having a minimum value of shear viscosity at 90 ° C. to 130 ° C. of 500 Pa · s or more when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min.

The thermosetting resin film of the present invention preferably contains a polymer component (A) and a thermosetting component (B).
The thermosetting resin film of the present invention preferably contains polyvinyl acetal.

The present invention also provides a first protective film forming sheet provided with the thermosetting resin film according to claim 1 on one surface of the first support sheet.

According to the present invention, the thermosetting resin film is a thermosetting resin film for forming a first protective film on the surface by sticking to a surface having bumps of a semiconductor wafer and thermosetting the semiconductor wafer. Provided is a thermosetting resin film capable of suppressing repelling on the surface of a semiconductor wafer when the film is affixed to a surface of a semiconductor wafer having bumps and heat-cured. Further, the present invention provides a first protective film forming sheet provided with this thermosetting resin film.

It is sectional drawing which shows typically one Embodiment of the thermosetting resin film and the 1st protective film formation sheet of this invention. FIG. 5 is a cross-sectional view schematically showing an example of how to use the thermosetting resin film and the first protective film forming sheet shown in FIG. 1. It is sectional drawing which shows typically an example of the use method of the thermosetting resin film of the comparative example and the sheet for forming a 1st protective film. It is a graph which shows the measurement result of the shear viscosity of the thermosetting resin film of an Example and a comparative example.

As used herein, the term "repellent on the surface of a semiconductor wafer" means that when a thermosetting resin film is thermally cured, it is temporarily melted and liquefied to expose the surface of the semiconductor wafer.
Further, in the present specification, the “surface of the semiconductor wafer” refers to a region excluding the bump surface from the surface of the semiconductor wafer having bumps.

FIG. 1 is a cross-sectional view schematically showing an embodiment of a thermosetting resin film and a first protective film forming sheet of the present invention. In addition, in the figure used in the following description, in order to make it easy to understand the features of the present invention, the main part may be enlarged for convenience, and the dimensional ratio of each component is the same as the actual one. Is not always the case.

The first protective film forming sheet 1 shown in FIG. 1 includes a first support sheet 101, and a thermosetting resin film 12 is provided on one surface 101a of the first support sheet 101. More specifically, the first protective film forming sheet 1 includes a buffer layer 13 on the first base material 11 and a thermosetting resin film 12 on the buffer layer 13, and the first base material 11 And the buffer layer 13 constitutes the first support sheet 101.

The first protective film forming sheet of the present invention is not limited to the one shown in FIG. 1, and a part of the structure shown in FIG. 1 is changed, deleted or added within the range not impairing the effect of the present invention. It may be the one that has been done.
For example, the first protective film forming sheet of the present invention includes a release film on the outermost layer (thermosetting resin film 12 in the first protective film forming sheet shown in FIG. 1) on the opposite side of the base material. You may.
Next, each layer constituting the first protective film forming sheet of the present invention will be described.

◎ Thermosetting resin film The thermosetting resin film is used to protect the bump forming surface (in other words, the circuit surface) of the semiconductor wafer and the bumps provided on the bump forming surface.

The thermosetting resin film of the present invention is softened by heating like a normal resin film, but is heat-cured by further heating, and is more heat than a thermosetting resin film at room temperature before heat curing. It has the property of becoming hard when returned to room temperature after curing. As a result, the first protective film formed on the surface having the bumps functions as a protective film. Then, when the thermosetting resin film before thermosetting is heated at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is 500 Pa · s or more, so that bumps on the semiconductor wafer can be formed. When it is attached to the surface of the wafer and thermoset, it does not melt or liquefy, and it is possible to prevent poor formation of the protective film due to cissing.
In addition, in this specification, "room temperature" means a temperature which is not particularly cooled or heated, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ° C.

“Shear viscosity” in the present specification is defined by using a shear viscosity measuring device to bring a measuring jig into contact with the top surface of a sample on a columnar shape having a diameter of 25 mm and a thickness of 500 μm, and having a frequency of 1 Hz and a heating rate of 10 ° C. It means a value measured every second from room temperature to 150 ° C. under the measurement conditions of.
The "room temperature" in the present specification means a normal temperature in a room, and examples thereof include a temperature of 5 ° C. to 30 ° C.

The thermosetting resin film for forming the first protective film on the surface of the semiconductor wafer having the bumps is for suppressing the residual thermosetting resin film on the upper part of the bumps (the top of the bumps and the region in the vicinity thereof). In addition, it was common to set the shear viscosity during heating to a predetermined value or less to increase the fluidity. However, if the shear viscosity of the thermosetting resin film at the time of heat curing is small, it becomes liquid by heating and aggregates in the vicinity of the bumps, which tends to cause repelling defects of the first protective film. Since the temperature at which the thermosetting resin film has the lowest shear viscosity differs depending on the composition, the shear viscosity may be the lowest at the curing temperature (heating set temperature), or the lowest shear viscosity at a temperature lower than that. It may be. Since repellent is likely to occur when the shear viscosity is less than 500 Pa · s when the thermosetting resin film is heat-cured, the minimum value of the shear viscosity in the heat-curing temperature range (heating start temperature to heating target temperature) is 500 Pa. -It is required to be s or more.

Therefore, when the temperature of the thermosetting resin film before thermosetting is raised at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. needs to be 500 Pa · s or more, and 1000 Pa · s. it is preferably s or more, more preferably 2000 Pa · s or more, more preferably ¹⁰ 4 Pa · s or more, particularly preferably 2 × ¹⁰ 4 Pa · s or more.

When the temperature of the thermosetting resin film before thermosetting is raised at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is such that the thermosetting resin film is applied to the surface of the semiconductor wafer having bumps. when attached, in order to suppress the remaining of the thermosetting resin film in the upper part of the bump is preferably at 10 6 ^Pa · s or less, more preferably 10 5 ^Pa · s or less, 6 It is particularly preferable that it is × 10 ⁴ Pa · s or less.

When the thermosetting resin film before thermosetting is heated at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is preferably 500 to 10 ⁶ Pa · s, and is 1000. It is more preferably 10 to ⁵ Pa · s, further preferably 2000 to 10 ⁵ Pa · s or less, particularly preferably 10 ⁴ to 10 ⁵ Pa · s, and 2 × 10 ^{4 to} 6 ×. Most preferably, it is 10 ⁴ Pa · s.

The thermosetting resin film is in the form of a sheet or a film, and the constituent material thereof is not particularly limited as long as the above conditions are satisfied.

The thermosetting resin film preferably contains a resin component and a filler, and contains a resin component, and the content of the filler is 45% by mass or less with respect to the total mass of the thermosetting resin film. Is more preferable, and 5 to 45% by mass is further preferable.
Further, in the thermosetting resin film, the weight average molecular weight of the resin component is preferably 1,000,000 or less, for example, 800,000 or less, 500,000 or less, 300,000 or less, 200,000 or less, 100,000 or less, 50,000 or less, or the like. You may.
On the other hand, in the thermosetting resin film, the lower limit of the weight average molecular weight of the resin component is not particularly limited, and may be, for example, 1000 or more, 5000 or more, or 8000 or more.
Further, in the thermosetting resin film, the weight average molecular weight of the resin component is, for example, 1000 to 1000000, 5000 to 80000, 800 to 500000, 800 to 30000, 800 to 20000, 800 to 10000, 800 to 50000, 800 to 00 to 00. It is preferably any one such as 30,000.
When the resin component satisfies each of these conditions, the first protective film forming sheet has a higher effect of suppressing the residual thermosetting resin film on the upper part of the bump.
In the present specification, the weight average molecular weight means a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method unless otherwise specified.

The thermosetting resin film contains a resin component, the content of the filler is 45% by mass or less with respect to the total mass of the thermosetting resin film, and the weight average molecular weight of the resin component is 30,000 or less. The content of the filler is 5 to 45% by mass with respect to the total mass of the thermosetting resin film, and the weight average molecular weight of the resin component is 8000 to 30000. Most preferred. By satisfying such a condition, the first protective film forming sheet is more effective in suppressing the residual thermosetting resin film on the upper part of the bump.
The types of the resin component and the filler are not particularly limited.

The thermosetting resin film can be formed by using a composition for forming a thermosetting resin film containing the constituent material.

Preferred thermosetting resin films include, for example, those containing a polymer component (A) as the resin component and further containing a thermosetting component (B).

The thermosetting resin film may have only one layer (single layer) or may have two or more layers. When the thermosetting resin film has a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.

The thickness of the thermosetting resin film is preferably 1 to 100 μm, more preferably 5 to 75 μm, and particularly preferably 5 to 50 μm. When the thickness of the thermosetting resin film is at least the above lower limit value, a first protective film having a higher protective ability can be formed. Further, when the thickness of the thermosetting resin film is not more than the upper limit value, it is possible to prevent the thickness from becoming excessive.
Here, the "thickness of the thermosetting resin film" means the thickness of the entire thermosetting resin film, and for example, the thickness of the thermosetting resin film composed of a plurality of layers means the thermosetting resin film. It means the total thickness of all the layers that make up.
As a method for measuring the thickness of the thermosetting resin film, for example, the thickness of the thermosetting resin film is measured at any five points using a contact type thickness gauge, and the average of the measured values is calculated. The method and the like can be mentioned. Hereinafter, the same method can be mentioned as the method for measuring the "thickness" in the present specification.

<< Composition for forming a thermosetting resin film >>
The thermosetting resin film can be formed by using a composition for forming a thermosetting resin film containing the constituent material. For example, a thermosetting resin film can be formed on a target portion by applying a composition for forming a thermosetting resin film to a surface to be formed of a thermosetting resin film and drying it if necessary. A more specific method for forming the thermosetting resin film will be described in detail later together with a method for forming other layers. The ratio of the contents of the components (also referred to as solids) that do not vaporize at room temperature in the composition for forming a thermosetting resin film is usually the same as the ratio of the contents of the components of the thermosetting resin film. Become.

The composition for forming a thermosetting resin film may be coated by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, and the like. Examples thereof include a method using various coaters such as a knife coater, a screen coater, a Meyer bar coater, and a kiss coater.

The drying conditions of the composition for forming a thermosetting resin film are not particularly limited, but the composition for forming a thermosetting resin film is preferably heat-dried when it contains a solvent described later. In this case, For example, it is preferable to dry at 70 to 130 ° C. for 10 seconds to 5 minutes.

<Composition for forming a resin layer>
The thermosetting resin film forming composition includes, for example, a thermosetting resin film forming composition containing a polymer component (A) and a thermosetting component (B) (in the present specification, simply "resin". (Sometimes abbreviated as "layer-forming composition") and the like.

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting film-forming property, flexibility, etc. to a thermosetting resin film, and is a component that can be regarded as being formed by a polymerization reaction of the polymerizable compound. In the present specification, the polymerization reaction also includes a polycondensation reaction.
The polymer component (A) contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When the polymer component (A) is two or more, the combination and ratio thereof can be arbitrarily selected.

Examples of the polymer component (A) include polyvinyl acetal, acrylic resin, polyester, urethane resin, acrylic urethane resin, silicone resin, rubber resin, phenoxy resin, thermoplastic polyimide, and the like, and are thermoset. It is easy to adjust the shear viscosity in the temperature range of the process, 90 ° C to 130 ° C, and when a thermosetting resin film is attached to the surface of the semiconductor wafer with bumps and thermosetting, the polymer Polyvinyl acetal and acrylic resins are preferable because the effect of suppressing repelling on the surface of the wafer is enhanced.

Examples of the polyvinyl acetal in the polymer component (A) include known ones.
Among them, preferable polyvinyl acetals include, for example, polyvinyl formal, polyvinyl butyral, and the like, and polyvinyl butyral is more preferable.
Examples of the polyvinyl butyral include those having a structural unit represented by the following formulas (i) -1, (i) -2 and (i) -3. Since it is easy to adjust the shear viscosity at 90 ° C. to 130 ° C., which is the temperature range of the thermosetting process, the polyvinyl butyral has the following formulas (i) -1, (i) -2 and (i)-. Those having a structural unit represented by 3 are preferable. Further, when the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing repelling on the surface of the semiconductor wafer becomes higher. Therefore, the polyvinyl butyral has the following formula. Those having the structural units represented by (i) -1, (i) -2 and (i) -3 are preferable.

In the formula, l ₁ , m ₁ and n ₁ are the content ratios (mol%) of the respective constituent units.

The weight average molecular weight (Mw) of the polyvinyl acetal is preferably 5000 to 20000, more preferably 8000 to 100,000, further preferably 9000 to 80000, and particularly preferably 1000 to 50000. When the weight average molecular weight of polyvinyl acetal is in such a range, when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min, the minimum value of shear viscosity at 90 ° C. to 130 ° C. is 500 Pa. It becomes easier to adjust than s, and when the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing repelling on the surface of the semiconductor wafer becomes higher. In addition, the effect of suppressing the residual thermosetting resin film at the upper portion of the bump (the top of the bump and the region in the vicinity thereof) becomes higher.

The content ratio l ₁ (degree of butyralization) of the structural unit of the butyral group is preferably 40 to 90 mol%, more preferably 50 to 85 mol%, and particularly preferably 60 to 76 mol%.

The content ratio m ₁ of the structural unit having an acetyl group is preferably 0.1 to 9 mol%, more preferably 0.5 to 8 mol%, and particularly preferably 1 to 7 mol%.

The content ratio n ₁ of the structural unit having a hydroxyl group is preferably 10 to 60 mol%, more preferably 10 to 50 mol%, and particularly preferably 20 to 40 mol%.

The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80 ° C, more preferably 50 to 70 ° C. When the Tg of the polyvinyl acetal is in such a range, when the thermosetting resin film is attached to the surface of the semiconductor wafer having the bumps, the effect of suppressing the residual of the thermosetting resin film on the upper part of the bumps is suppressed. Will be higher. In addition, when Tg is in such a range, sufficient hardness of the first protective film after thermosetting can be obtained.
In the present specification, the "glass transition temperature (Tg)" is expressed by the temperature of the inflection point of the obtained DSC curve obtained by measuring the DSC curve of the sample using a differential scanning calorimeter.

The ratio of three or more kinds of monomers constituting the polyvinyl acetal can be arbitrarily selected.

Examples of the acrylic resin in the polymer component (A) include known acrylic polymers.
The weight average molecular weight (Mw) of the acrylic resin is preferably 1000 to 2000000, and more preferably 100,000 to 1500,000. Since the weight average molecular weight of the acrylic resin is in this range, when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min, the minimum value of shear viscosity at 90 ° C. to 130 ° C. is 500 Pa · s. As described above, the adjustment becomes easier, and when the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing cissing on the surface of the semiconductor wafer becomes higher. In addition, the shape stability is excellent, the thermosetting resin film easily follows the uneven surface of the adherend, and the generation of voids and the like between the adherend and the thermosetting resin film is further suppressed.

The glass transition temperature (Tg) of the acrylic resin is preferably −50 to 70 ° C., more preferably -30 to 50 ° C. When the Tg of the acrylic resin is at least the above lower limit value, the adhesive force between the first protective film and the first support sheet is suppressed, and the peelability of the first support sheet is improved. Further, when the Tg of the acrylic resin is not more than the above upper limit value, the adhesive force of the thermosetting resin film and the first protective film to the adherend is improved.

Examples of the acrylic resin include polymers of one or more (meth) acrylic acid esters; in addition to (meth) acrylic acid esters, (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and the like. Examples thereof include a copolymer obtained by copolymerizing one or more monomers selected from N-methylolacrylamide and the like.
In addition, in this specification, "(meth) acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth) acrylic acid, for example, "(meth) acrylate" is a concept that includes both "acrylate" and "methacrylate", and is a "(meth) acryloyl group". Is a concept that includes both an "acryloyl group" and a "methacryloyl group".

Examples of the (meth) acrylic acid ester constituting the acrylic resin include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and (meth). ) N-butyl acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic Heptyl acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate , (Meta) undecyl acrylate, (meth) dodecyl acrylate (also called (meth) lauryl acrylate), (meth) tridecyl acrylate, tetradecyl (meth) acrylate (also called myristyl (meth) acrylate), ( Alkyl such as pentadecyl acrylate, hexadecyl (meth) acrylate (also called palmityl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (also called stearyl (meth) acrylate) The (meth) acrylic acid alkyl ester in which the alkyl group constituting the ester has a chain structure having 1 to 18 carbon atoms;
(Meta) Acrylic acid cycloalkyl esters such as (meth) acrylic acid isobornyl, (meth) acrylic acid dicyclopentanyl;
(Meta) Acrylic acid aralkyl esters such as benzyl (meth) acrylic acid;
(Meta) Acrylic acid cycloalkenyl ester such as (meth) acrylic acid dicyclopentenyl ester;
(Meta) Acrylic acid cycloalkenyloxyalkyl ester such as (meth) acrylic acid dicyclopentenyloxyethyl ester;
(Meta) acrylate imide;
A glycidyl group-containing (meth) acrylic acid ester such as glycidyl (meth) acrylate;
Hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth) ) Hydroxyl-containing (meth) acrylic acid esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate;
Examples thereof include substituted amino group-containing (meth) acrylic acid esters such as N-methylaminoethyl (meth) acrylic acid. Here, the "substituted amino group" means a group in which one or two hydrogen atoms of the amino group are substituted with a group other than the hydrogen atom.

The monomer constituting the acrylic resin may be only one kind or two or more kinds. When the number of monomers constituting the acrylic resin is two or more, the combination and ratio thereof can be arbitrarily selected.

The acrylic resin may have a functional group capable of binding to other compounds such as a vinyl group, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group and an isocyanate group. The functional group of the acrylic resin may be bonded to another compound via a cross-linking agent (F) described later, or may be directly bonded to another compound without a cross-linking agent (F). .. When the acrylic resin is bonded to another compound by the functional group, the reliability of the package obtained by using the first protective film forming sheet tends to be improved.

In the present invention, for example, as the polymer component (A), a thermoplastic resin other than polyvinyl acetal and acrylic resin (hereinafter, may be simply abbreviated as “thermoplastic resin”) is used as polyvinyl acetal and acrylic resin. May be used alone without using, or may be used in combination with polyvinyl acetal or an acrylic resin. By using the thermoplastic resin, the peelability of the first protective film from the first support sheet is improved, the thermosetting resin film easily follows the uneven surface of the adherend, and the adherend and the thermosetting are thermally cured. The generation of voids and the like with the sex resin film may be further suppressed.

The weight average molecular weight of the thermoplastic resin is preferably 1000 to 100,000, more preferably 3000 to 80,000.

The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150 ° C, more preferably -20 to 120 ° C.

Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene and the like.

The thermoplastic resin contained in the resin layer forming composition and the thermosetting resin film may be of only one type or of two or more types. When there are two or more types of the thermoplastic resin, the combination and ratio thereof can be arbitrarily selected.

In the resin layer forming composition, the ratio of the content of the polymer component (A) to the total content of all the components other than the solvent (total mass of the solid content of the resin layer forming composition) (that is, thermosetting property). The content of the polymer component (A) of the resin film) is preferably 5 to 85% by mass, more preferably 5 to 80% by mass, regardless of the type of the polymer component (A). For example, it may be any of 5 to 70% by mass, 5 to 60% by mass, 5 to 50% by mass, 5 to 40% by mass, and 5 to 30% by mass. However, these contents in the composition for forming a resin layer are examples.

The polymer component (A) may also correspond to the thermosetting component (B). In the present specification, when the composition for forming a resin layer contains a component corresponding to both the polymer component (A) and the thermosetting component (B), the composition for forming a resin layer is described. It is considered to contain the polymer component (A) and the thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) is a component for curing a thermosetting resin film to form a hard first protective film.
The thermosetting component (B) contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When there are two or more thermosetting components (B), their combinations and ratios can be arbitrarily selected.

Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, silicone resins, and the like, and epoxy-based thermosetting resins are preferable.

(Epoxy thermosetting resin)
The epoxy-based thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2).
The epoxy-based thermosetting resin contained in the resin layer forming composition and the thermosetting resin film may be only one type or two or more types. When there are two or more types of epoxy thermosetting resins, their combinations and ratios can be arbitrarily selected.

・ Epoxy resin (B1)
Examples of the epoxy resin (B1) include known ones, such as polyfunctional epoxy resin, biphenyl compound, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolac epoxy resin, and dicyclopentadiene type epoxy resin. Biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, and other bifunctional or higher functional epoxy compounds can be mentioned.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used. An epoxy resin having an unsaturated hydrocarbon group has higher compatibility with an acrylic resin than an epoxy resin having no unsaturated hydrocarbon group. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of the package obtained by using the first protective film forming sheet is improved.

Examples of the epoxy resin having an unsaturated hydrocarbon group include a compound obtained by converting a part of the epoxy group of the polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such a compound can be obtained, for example, by subjecting an epoxy group to an addition reaction of (meth) acrylic acid or a derivative thereof.
Examples of the epoxy resin having an unsaturated hydrocarbon group include a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin.
The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (also referred to as a vinyl group), a 2-propenyl group (also referred to as an allyl group), and a (meth) acryloyl group. , (Meta) acrylamide group and the like, and an acryloyl group is preferable.

The weight average molecular weight of the epoxy resin (B1) is preferably 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. When the weight average molecular weight of the epoxy resin (B1) is not more than the above upper limit value, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. when the thermosetting resin film before curing is heated at 10 ° C./min. Can be easily adjusted to 500 Pa · s or more, and when a thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing cissing on the surface of the semiconductor wafer becomes higher. .. Further, at the top of the bump, the effect of suppressing the residual of the first protective film residue becomes higher.

The lower limit of the weight average molecular weight of the epoxy resin (B1) is not particularly limited. However, the weight average molecular weight of the epoxy resin (B1) is preferably 300 or more, preferably 500 or more, in terms of further improving the curability of the thermosetting resin film and the strength and heat resistance of the first protective film. More preferably.

The weight average molecular weight of the epoxy resin (B1) can be appropriately adjusted so as to be within a range set by arbitrarily combining the above-mentioned preferable lower limit value and upper limit value.
For example, in one embodiment, the weight average molecular weight of the epoxy resin (B1) is preferably 300 to 15,000, more preferably 300 to 10000, and particularly preferably 300 to 3000. Further, in one embodiment, the weight average molecular weight of the epoxy resin (B1) is preferably 500 to 15,000, more preferably 500 to 10000, and particularly preferably 500 to 3000. However, these are examples of preferable weight average molecular weights of the epoxy resin (B1).

The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g / eq, more preferably 130 to 800 g / eq.
As used herein, "epoxy equivalent" means the number of grams (g / eq) of an epoxy compound containing 1 gram equivalent of an epoxy group, and can be measured according to the method of JIS K 7236: 2001.

The epoxy resin (B1) is preferably liquid at room temperature (in the present specification, it may be simply referred to as "liquid epoxy resin (B1)"). It is preferable to use an epoxy resin that is liquid at room temperature because it is easy to adjust the shear viscosity.

One type of epoxy resin (B1) may be used alone, or two or more types may be used in combination. When two or more types of epoxy resins (B1) are used in combination, their combinations and ratios can be arbitrarily selected.

The ratio of the liquid epoxy resin (B1) to the epoxy resin (B1) contained in the resin layer forming composition and the thermosetting resin film is 40% by mass with respect to the total mass of the epoxy resin (B1). The above is preferable, 50% by mass or more is more preferable, 55% by mass or more is particularly preferable, and for example, 60% by mass or more, 70% by mass or more, 80% by mass or more, and 90% by mass or more. It may be any of. When the ratio is equal to or higher than the lower limit, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. can be easily set to 500 Pa · s or more when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min. When the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing cissing on the surface of the semiconductor wafer becomes higher. Further, at the top of the bump, the effect of suppressing the residual of the first protective film residue becomes higher.
The upper limit of the ratio is not particularly limited, and the ratio may be 100% by mass or less.
The ratio of the liquid epoxy resin (B1) to the epoxy resin (B1) contained in the resin layer forming composition and the thermosetting resin film is 40% by mass with respect to the total mass of the epoxy resin (B1). More than 100% by mass is preferable, 50% by mass or more and 100% by mass or less is more preferable, and 55% by mass or more and 100% by mass or less is particularly preferable.
The ratio of the liquid epoxy resin (B1) to the epoxy resin (B1) contained in the resin layer forming composition and the thermosetting resin film is 60% by mass with respect to the total mass of the epoxy resin (B1). It may be any one of 100% by mass or less, 70% by mass or more and 100% by mass or less, 80% by mass or more and 100% by mass or less, and 90% by mass or more and 100% by mass or less.

・ Thermosetting agent (B2)
The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1).
Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxy group, a group in which an acid group is anhydrous, and the phenolic hydroxyl group, an amino group, or an acid group is anhydrous. It is preferably a group, more preferably a phenolic hydroxyl group or an amino group.

Among the thermosetting agents (B2), examples of the phenolic curing agent having a phenolic hydroxyl group include polyfunctional phenol resin, biphenol, novolak type phenol resin, dicyclopentadiene type phenol resin, and aralkyl type phenol resin. ..
Among the thermosetting agents (B2), examples of the amine-based curing agent having an amino group include dicyandiamide (in this specification, it may be abbreviated as "DICY") and the like.

The thermosetting agent (B2) may have an unsaturated hydrocarbon group.
The thermosetting agent (B2) having an unsaturated hydrocarbon group is, for example, a compound in which a part of the hydroxyl group of the phenol resin is replaced with a group having an unsaturated hydrocarbon group, which is not suitable for the aromatic ring of the phenol resin. Examples thereof include compounds in which a group having a saturated hydrocarbon group is directly bonded.
The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having the unsaturated hydrocarbon group described above.

When a phenolic curing agent is used as the thermosetting agent (B2), the thermosetting agent (B2) has a softening point or a glass transition temperature because the peelability of the first protective film from the first support sheet is improved. Higher ones are preferable.

Among the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resin, novolak type phenol resin, dicyclopentadiene type phenol resin, and aralkyl type phenol resin is preferably 300 to 30,000. , 400 to 10000, and particularly preferably 500 to 3000.
As used herein, "number average molecular weight" means a number average molecular weight represented by a standard polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method, unless otherwise specified.
The molecular weight of the non-resin component such as biphenol and dicyandiamide in the thermosetting agent (B2) is not particularly limited, but is preferably 60 to 500, for example.

One type of thermosetting agent (B2) may be used alone, or two or more types may be used in combination. When two or more types of thermosetting agents (B2) are used in combination, their combinations and ratios can be arbitrarily selected.

In the composition for forming a resin layer and the thermosetting resin film, the content of the thermosetting agent (B2) is 0.1 to 500 parts by mass with respect to 100 parts by mass of the content of the epoxy resin (B1). Is preferable, and it is more preferably 1 to 200 parts by mass, for example, any one of 1 to 150 parts by mass, 1 to 100 parts by mass, 1 to 75 parts by mass, 1 to 50 parts by mass, and 1 to 30 parts by mass. It may be. When the content of the thermosetting agent (B2) is at least the lower limit value, the curing of the thermosetting resin film becomes easier to proceed. Further, when the content of the thermosetting agent (B2) is not more than the upper limit value, the hygroscopicity of the thermosetting resin film is reduced, and the reliability of the package obtained by using the first protective film is improved. Improve more.

In the resin layer forming composition and the thermosetting resin film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is the polymer component (for example). The content of A) is preferably 50 to 1000 parts by mass, more preferably 60 to 950 parts by mass, and particularly preferably 70 to 900 parts by mass with respect to 100 parts by mass. When the content of the thermosetting component (B) is in such a range, the adhesive force between the first protective film and the first support sheet is suppressed, and the peelability of the first support sheet is improved.

[Curing accelerator (C)]
The resin layer forming composition and the thermosetting resin film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the composition for forming a resin layer.
Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol and tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole. , 2-Phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole and other imidazoles (one or more hydrogen atoms other than hydrogen atoms) (Imidazole substituted with an organic group); organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine (phosphine in which one or more hydrogen atoms are substituted with an organic group); tetraphenylphosphonium tetraphenylborate, triphenylphosphine Examples thereof include tetraphenylborone salts such as tetraphenylborate.

The curing accelerator (C) contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When there are two or more types of curing accelerators (C), their combinations and ratios can be arbitrarily selected.

When the curing accelerator (C) is used, the content of the curing accelerator (C) in the resin layer forming composition and the thermosetting resin film is based on 100 parts by mass of the content of the thermosetting component (B). The amount is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass. When the content of the curing accelerator (C) is at least the lower limit value, the effect of using the curing accelerator (C) is more remarkable. Further, when the content of the curing accelerator (C) is not more than the above upper limit value, for example, the highly polar curing accelerator (C) is adhered to the thermosetting resin film under high temperature and high humidity conditions. The effect of suppressing segregation by moving to the adhesion interface side with the body is enhanced, and the reliability of the package obtained by using the first protective film forming sheet is further improved.

[Filler (D)]
The resin layer forming composition and the thermosetting resin film may contain a filler (D). Since the thermosetting resin film contains the filler (D), the coefficient of thermal expansion of the first protective film obtained by curing the thermosetting resin film can be easily adjusted. Then, by optimizing this coefficient of thermal expansion with respect to the object to be formed of the first protective film, the reliability of the package obtained by using the first protective film forming sheet is further improved. Further, when the thermosetting resin film contains the filler (D), the hygroscopicity of the first protective film can be reduced and the heat dissipation can be improved.

The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.
Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride and the like; spherical beads of these inorganic fillers; surface modification of these inorganic fillers. Goods; Single crystal fibers of these inorganic fillers; Glass fibers and the like.
Among these, the inorganic filler is preferably silica or alumina.

The filler (D) contained in the resin layer forming composition and the thermosetting resin film may be of only one type or of two or more types. When there are two or more types of filler (D), their combinations and ratios can be arbitrarily selected.

The average particle size of the filler (D) is preferably 1 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.1 μm or less. When the average particle size of the filler (D) is not more than the above upper limit value, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min. Can be easily adjusted to 500 Pa · s or more, and when a thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the effect of suppressing repelling on the surface of the semiconductor wafer becomes higher. ..
Further, at the top of the bump, the effect of suppressing the residual of the first protective film residue becomes higher.
In the present specification, the "average particle size" means the value of the particle size (D ₅₀ ) at an integrated value of 50% in the particle size distribution curve obtained by the laser diffraction / scattering method unless otherwise specified. ..

The lower limit of the average particle size of the filler (D) is not particularly limited. For example, the average particle size of the filler (D) is preferably 0.01 μm or more in that the filler (D) is more easily available.
The average particle size of the filler (D) is preferably 0.01 μm or more and 1 μm or less, more preferably 0.01 μm or more and 0.5 μm or less, and preferably 0.01 μm or more and 0.1 μm or less. Especially preferable.

When the filler (D) is used, the ratio of the content of the filler (D) to the total content of all the components other than the solvent in the resin layer forming composition (that is, the filler of the thermosetting resin film (that is,) The content of D)) is preferably 3 to 60% by mass, more preferably 3 to 55% by mass. When the content of the filler (D) is in such a range, when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is set. It can be easily adjusted to 500 Pa · s or more, and when the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the repelling of the surface of the semiconductor wafer can be suppressed. Further, at the top of the bump, the effect of suppressing the residual of the first protective film residue becomes higher, and the above-mentioned coefficient of thermal expansion becomes easier to adjust.

[Coupling agent (E)]
The resin layer forming composition and the thermosetting resin film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the thermosetting resin film to the adherend can be improved. Further, by using the coupling agent (E), the first protective film obtained by curing the thermosetting resin film has improved water resistance without impairing heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups of the polymer component (A), the thermosetting component (B) and the like, and is preferably a silane coupling agent. More preferred.
Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-. (3,4-Epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-amino) Ethylamino) propylmethyldiethoxysilane, 3- (phenylamino) propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyl Examples thereof include dimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.

The coupling agent (E) contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When the number of coupling agents (E) is two or more, the combination and ratio thereof can be arbitrarily selected.

When the coupling agent (E) is used, the content of the coupling agent (E) in the resin layer forming composition and the thermosetting resin film is the content of the polymer component (A) and the thermosetting component (B). The total content is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass with respect to 100 parts by mass. ..
When the content of the coupling agent (E) is equal to or higher than the lower limit, the dispersibility of the filler (D) in the resin is improved and the adhesiveness of the thermosetting resin film to the adherend is improved. The effect of using the coupling agent (E) is more remarkable. Further, when the content of the coupling agent (E) is not more than the upper limit value, the generation of outgas is further suppressed.

[Crosslinking agent (F)]
As the polymer component (A), a polymer component (A) having a vinyl group capable of binding to another compound, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group, an isocyanate group, or the like, such as the above-mentioned acrylic resin, is used. When used, the resin layer forming composition and the thermosetting resin film may contain a cross-linking agent (F). The cross-linking agent (F) is a component for bonding the functional group in the polymer component (A) with another compound to cross-link, and by cross-linking in this way, initial adhesion of the thermosetting resin film is performed. The force and cohesive force can be adjusted.

Examples of the cross-linking agent (F) include an organic polyvalent isocyanate compound, an organic polyvalent imine compound, a metal chelate-based cross-linking agent (cross-linking agent having a metal chelate structure), an aziridine-based cross-linking agent (cross-linking agent having an aziridinyl group), and the like. Can be mentioned.

Examples of the organic polyvalent isocyanate compound include an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound, and an alicyclic polyvalent isocyanate compound (hereinafter, these compounds are collectively referred to as “aromatic polyvalent isocyanate compound and the like”. (May be abbreviated); trimerics such as the aromatic polyvalent isocyanate compound, isocyanurates and adducts; terminal isocyanate urethane prepolymer obtained by reacting the aromatic polyvalent isocyanate compound and the like with a polyol compound. And so on. The "adduct" includes the aromatic polyhydric isocyanate compound, the aliphatic polyhydric isocyanate compound, or the alicyclic polyvalent isocyanate compound, and low ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, and the like. It means a reaction product with a molecularly active hydrogen-containing compound. Examples of the adduct body include a xylylene diisocyanate adduct of trimethylolpropane, which will be described later. Further, the "terminal isocyanate urethane prepolymer" is as described above.

More specifically, as the organic polyvalent isocyanate compound, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; diphenylmethane-4. , 4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; trimethylol Compounds in which one or more of tolylene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate are added to all or part of the hydroxyl groups of a polyol such as propane; lysine diisocyanate and the like can be mentioned.

Examples of the organic polyvalent imine compound include N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxyamide), trimethylpropan-tri-β-aziridinyl propionate, and tetramethylolmethane. Examples thereof include -tri-β-aziridinyl propionate, N, N'-toluene-2,4-bis (1-aziridinecarboxyamide) triethylene melamine and the like.

When an organic multivalent isocyanate compound is used as the cross-linking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the cross-linking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, the reaction between the cross-linking agent (F) and the polymer component (A) gives the thermosetting resin film a cross-linked structure. Can be easily introduced.

The cross-linking agent (F) contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When the number of the cross-linking agent (F) is two or more, the combination and ratio thereof can be arbitrarily selected.

When the cross-linking agent (F) is used, the content of the cross-linking agent (F) in the resin layer forming composition is 0.01 to 20 parts by mass with respect to 100 parts by mass of the content of the polymer component (A). It is preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass. When the content of the cross-linking agent (F) is at least the lower limit value, the effect of using the cross-linking agent (F) is more remarkable. Further, when the content of the cross-linking agent (F) is not more than the upper limit value, excessive use of the cross-linking agent (F) is suppressed.

[Other ingredients]
The composition for forming a resin layer and the thermosetting resin film are filled with the above-mentioned polymer component (A), thermosetting component (B), curing accelerator (C), and filling as long as the effects of the present invention are not impaired. It may contain other components other than the material (D), the coupling agent (E) and the cross-linking agent (F).
Examples of the other components include energy ray-curable resins, photopolymerization initiators, colorants, general-purpose additives and the like. The general-purpose additive is known and can be arbitrarily selected depending on the intended purpose, and is not particularly limited, but preferred ones are, for example, plasticizers, antistatic agents, antioxidants, and colorants (dye, pigment). ), Gettering agent and the like.

The other components contained in the resin layer forming composition and the thermosetting resin film may be only one kind or two or more kinds. When the other components are two or more, their combinations and ratios can be arbitrarily selected.
The contents of the other components of the resin layer forming composition and the thermosetting resin film are not particularly limited and may be appropriately selected depending on the intended purpose.

The resin layer forming composition and the thermosetting resin film contain a polymer component (A) and a thermosetting component (B), contain polyvinyl acetal as the polymer component (A), and an epoxy resin (B1). ), It is preferable to contain a liquid one, and more preferably one containing a curing accelerator (C) and a filler (D) in addition to these components. The filler (D) in this case preferably has the above-mentioned average particle size. By using such a composition for forming a resin layer and a thermosetting resin film, when the temperature of the thermosetting resin film before curing is raised at 10 ° C./min, the minimum shear viscosity at 90 ° C. to 130 ° C. The value can be easily adjusted to 500 Pa · s or more, and when the thermosetting resin film is attached to the surface of the semiconductor wafer having bumps and heat-cured, the repelling of the surface of the semiconductor wafer can be suppressed. Further, at the top of the bump, the effect of suppressing the residual of the first protective film residue becomes higher.

The resin layer forming composition and the thermosetting resin film contain at least one selected from polyvinyl formal, polyvinyl butyral, and acrylic resin as the polymer component (A), and are liquid as the epoxy resin (B1). It is preferable to contain at least one selected from a cyclopentadiene type epoxy resin and a liquid bisphenol A type epoxy resin, and in addition to these components, 2-phenyl-4-methylimidazole and 2 as a curing accelerator (C) are further contained. More preferably, it contains at least one selected from −phenyl-4,5-dihydroxymethylimidazole and at least one selected from silica and alumina as the filler (D).

[solvent]
The composition for forming a resin layer preferably further contains a solvent. The composition for forming a resin layer containing a solvent has good handleability.
The solvent is not particularly limited, but preferred ones include, for example, hydrocarbons such as toluene and xylene; methanol, ethanol, 2-propanol, isobutyl alcohol (also referred to as 2-methylpropan-1-ol), 1-butanol and the like. Alcohols; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides such as dimethylformamide and N-methylpyrrolidone (compounds having an amide bond) and the like.
The solvent contained in the resin layer forming composition may be only one kind or two or more kinds. When the solvent is two or more kinds, the combination and the ratio thereof can be arbitrarily selected.

The solvent contained in the resin layer forming composition is preferably methyl ethyl ketone or the like from the viewpoint that the components contained in the resin layer forming composition can be mixed more uniformly.

The content of the solvent in the resin layer forming composition is not particularly limited, and may be appropriately selected depending on the type of the component other than the solvent, for example.

<< Manufacturing method of composition for forming thermosetting resin film >>
A composition for forming a thermosetting resin film such as a composition for forming a resin layer can be obtained by blending each component for forming the same.
The order of addition of each component at the time of blending is not particularly limited, and two or more kinds of components may be added at the same time.
When a solvent is used, the solvent may be mixed with any compounding component other than the solvent and diluted in advance, or any compounding component other than the solvent may be diluted in advance. You may use it by mixing the solvent with these compounding components without leaving.
The method of mixing each component at the time of blending is not particularly limited, and from known methods such as a method of rotating a stirrer or a stirring blade to mix; a method of mixing using a mixer; a method of adding ultrasonic waves to mix. It may be selected as appropriate.
The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

(1) First Support Sheet In the first protective film forming sheet 1, a known one can be used as the first support sheet 101. For example, the first support sheet 101 is configured to include a first base material 11 and a buffer layer 13 formed on the first base material 11. That is, the first protective film forming sheet 1 is formed by laminating the first base material 11, the cushioning layer 13, and the thermosetting resin film 12 in this order in the thickness direction.

(1) First base material The first base material is in the form of a sheet or a film, and examples of the constituent materials thereof include various resins.
Examples of the resin include polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE); other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin. Polyethylene; polyethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-norbornene copolymer (ethylene as monomer) (Copolymer obtained using); Vinyl chloride resin such as polyvinyl chloride, vinyl chloride copolymer (resin obtained using vinyl chloride as a monomer); Polystyrene; Polycycloolefin; Polyethylene terephthalate, polyethylene Polyethylenes such as naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, all aromatic polyesters in which all constituent units have an aromatic cyclic group; co-operation of two or more of the above polyesters. Polymers; poly (meth) acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; polyether ketones and the like.
Further, examples of the resin include polymer alloys such as a mixture of the polyester and other resins. The polymer alloy of the polyester and the resin other than the polyester preferably has a relatively small amount of the resin other than the polyester.
The resin may be, for example, a crosslinked resin obtained by cross-linking one or more of the resins exemplified above; modification of an ionomer or the like using one or more of the resins exemplified so far. Resin is also mentioned.

The resin constituting the first base material may be only one type or two or more types. When the resin constituting the first base material is two or more kinds, the combination and ratio thereof can be arbitrarily selected.

The first base material may be only one layer (single layer) or may have two or more layers. When the first base material is a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.
In the present specification, not only in the case of the first base material, "a plurality of layers may be the same or different from each other" means "all layers may be the same or all layers". May be different, and only some layers may be the same. " Further, "a plurality of layers are different from each other" means that "at least one of the constituent materials and the thickness of each layer is different from each other".

The thickness of the first base material is preferably 5 to 1000 μm, more preferably 10 to 500 μm, further preferably 15 to 300 μm, and particularly preferably 20 to 150 μm.
Here, the "thickness of the first base material" means the thickness of the entire first base material, and for example, the thickness of the first base material composed of a plurality of layers is all that constitute the first base material. Means the total thickness of the layers of.

The first base material preferably has a high thickness accuracy, that is, a material in which variation in thickness is suppressed regardless of the site. Among the above-mentioned constituent materials, as a material that can be used to construct a first base material having such a high accuracy of thickness, for example, polyethylene, polyolefin other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate co-weight. Coalescence and the like can be mentioned.

In addition to the main constituent materials such as the resin, the first base material contains various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (also referred to as plasticizers). May be contained.

The first base material may be transparent, opaque, colored depending on the purpose, or another layer may be vapor-deposited.
When the thermosetting resin film is energy ray curable, it is preferable that the first base material transmits energy rays.

The first substrate can be produced by a known method. For example, the first base material containing a resin can be produced by molding a resin composition containing the resin.

◎ Release film The release film may be one known in the art.
The preferred release film is, for example, one in which at least one surface of a resin film such as polyethylene terephthalate is peeled by a silicone treatment or the like; at least one surface of the film is a release surface made of polyolefin. And so on.
The thickness of the release film is preferably the same as the thickness of the first base material.

◎ Buffer layer The buffer layer 13 has a buffering action against the force applied to the buffer layer 13 and the layer adjacent thereto. In the present embodiment, the thermosetting resin film 12 is shown as the "layer adjacent to the cushioning layer".

The cushioning layer 13 is preferably in the form of a sheet or a film and is energy ray-curable. By curing the energy ray-curable cushioning layer 13 with energy rays, it becomes easier to peel off from the thermosetting resin film 12 described later.

Examples of the constituent material of the buffer layer 13 include various adhesive resins. Examples of the adhesive resin include adhesive resins such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, and polycarbonate, and acrylic resin is preferable. When the buffer layer 13 is energy ray-curable, various components necessary for energy ray curing can be mentioned as constituent materials thereof.

In the present invention, the "adhesive resin" is a concept including both a resin having adhesiveness and a resin having adhesiveness. For example, not only the resin itself has adhesiveness but also the resin itself has adhesiveness. It also includes a resin that exhibits adhesiveness when used in combination with other components such as additives, and a resin that exhibits adhesiveness due to the presence of a trigger such as heat or water.

The buffer layer 13 may be only one layer (single layer), or may have two or more layers. When the buffer layer 13 is a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.

The thickness of the buffer layer 13 is preferably 30 to 500 μm.
Here, the "thickness of the buffer layer 13" means the thickness of the entire buffer layer 13, and for example, the thickness of the buffer layer 13 composed of a plurality of layers is the total of all the layers constituting the buffer layer 13. Means the thickness of.

<< Adhesive resin composition >>
The buffer layer 13 can be formed by using an adhesive resin composition containing an adhesive resin. For example, the buffer layer 13 can be formed at a target portion by applying the adhesive resin composition to the surface to be formed of the buffer layer 13 and drying it if necessary.

The coating of the adhesive resin composition may be carried out by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, and a screen. Examples thereof include a method using various coaters such as a coater, a Meyer bar coater, and a knife coater.

The drying conditions of the adhesive resin composition are not particularly limited, but it is preferable that the adhesive resin composition containing a solvent described later is heat-dried. The adhesive resin composition containing the solvent is preferably dried at 70 to 130 ° C. for 10 seconds to 5 minutes, for example.

When the buffer layer 13 is energy ray curable, the adhesive resin composition containing the energy ray curable pressure-sensitive adhesive, that is, the energy ray curable adhesive resin composition is, for example, non-energy ray curable. An adhesive resin composition (I-1) containing an adhesive resin (I-1a) (hereinafter, may be abbreviated as "adhesive resin (I-1a)") and an energy ray-curable compound. An energy ray-curable adhesive resin (I-2a) in which an unsaturated group is introduced into the side chain of a non-energy ray-curable adhesive resin (I-1a) (hereinafter, "adhesive resin (I-2a)". ) ”) Is contained in the adhesive resin composition (I-2); the adhesive resin composition containing the adhesive resin (I-2a) and an energy ray-curable low molecular weight compound. The thing (I-3) and the like can be mentioned.

Examples of the adhesive resin composition include non-energy ray-curable adhesive resin compositions as well as energy ray-curable adhesive resin compositions.
Examples of the non-energy ray-curable adhesive resin composition include non-energy rays such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, and ester resin. Examples thereof include an adhesive resin composition (I-4) containing a curable adhesive resin (I-1a), and those containing an acrylic resin are preferable.

<< Manufacturing method of adhesive resin composition >>
The adhesive resin compositions such as the adhesive resin compositions (I-1) to (I-4) are composed of the adhesive resin and, if necessary, components other than the adhesive resin. It is obtained by blending each component for composing a product.
The order of addition of each component at the time of blending is not particularly limited, and two or more kinds of components may be added at the same time.
When a solvent is used, the solvent may be mixed with any compounding component other than the solvent and diluted in advance, or any compounding component other than the solvent may be diluted in advance. You may use it by mixing the solvent with these compounding components without leaving.
The method of mixing each component at the time of blending is not particularly limited, and from known methods such as a method of rotating a stirrer or a stirring blade to mix; a method of mixing using a mixer; a method of adding ultrasonic waves to mix. It may be selected as appropriate.
The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

-Method of manufacturing the first protective film forming sheet The first protective film forming sheet can be manufactured by sequentially laminating the above-mentioned layers so as to have a corresponding positional relationship. The method of forming each layer is as described above.

For example, the first protective film forming sheet in which the cushioning layer and the thermosetting resin film are laminated in this order on the first base material in the thickness direction thereof can be produced by the method shown below. That is, the buffer layer is laminated on the first base material by extrusion-molding the adhesive resin composition for forming the buffer layer on the first base material. Further, the thermosetting resin film is laminated by applying the above-mentioned composition for forming a thermosetting resin film on the peeling surface of the release film and drying it if necessary. Then, by laminating the thermosetting resin film on the release film with the cushioning layer on the first base material, the cushioning layer, the thermosetting resin film and the release film are laminated in this order on the first base material. A sheet for forming a first protective film is obtained. The release film may be removed when the first protective film forming sheet is used.

In the above-mentioned manufacturing method, the first protective film forming sheet provided with the other layers other than the above-mentioned layers is formed in the step of forming the other layers and so as to have an appropriate stacking position of the other layers. It can be manufactured by appropriately adding either one or both of the laminating steps.

For example, the first protective film forming sheet in which the adhesion layer, the cushioning layer, and the thermosetting resin film are laminated in this order on the first base material in the thickness direction thereof can be produced by the method shown below. .. That is, by co-extrusion molding the composition for forming the adhesion layer and the adhesive resin composition for forming the buffer layer on the first base material, the adhesion layer and the buffer layer are laminated on the first base material in this order. To do. Then, a thermosetting resin film is separately laminated on the release film by the same method as described above. Next, by laminating the thermosetting resin film on the release film with the first base material and the buffer layer on the adhesion layer, the adhesion layer, the buffer layer, the thermosetting resin film and the heat-curable resin film are formed on the first base material. A first protective film forming sheet obtained by laminating the release films in this order is obtained. The release film on the thermosetting resin film may be removed when the first protective film forming sheet is used.

-Method of using the first protective film forming sheet The first protective film forming sheet of the present invention can be used, for example, as follows.
That is, first, the first protective film forming sheet is attached to the bump forming surface of the semiconductor wafer by the thermosetting resin film. At this time, by laminating the thermosetting resin film while heating, the thermosetting resin film is softened and the thermosetting resin film is brought into close contact with the bump forming surface.
Then, if necessary, the surface of the semiconductor wafer opposite to the bump forming surface (that is, the back surface) is ground, and then a protective film forming sheet for protecting the back surface (in the present specification) is used on the back surface. , Referred to as "second protective film forming sheet"). Examples of the second protective film forming sheet include those provided with a second protective film forming film for forming a second protective film for protecting the back surface of the semiconductor wafer and the semiconductor chip by curing, and further dicing. It may be configured to include a sheet.

Next, of the first protective film forming sheet bonded to the bump forming surface of the semiconductor wafer, only the thermosetting resin film is left on the bump forming surface, and the other layers are peeled off from the thermosetting resin film. Here, the "other layer to be peeled off" is, for example, the first base material 11 and the buffer layer 13 in the case of the first protective film forming sheet 1 shown in FIG.
Next, the thermosetting resin film is cured to form a first protective film on the bump forming surface of the semiconductor wafer.

After that, the semiconductor device can be manufactured by the same method as the conventional method. That is, the semiconductor wafer provided with the first protective film is diced to form a semiconductor chip, and the semiconductor chip provided with the first protective film is picked up. The second protective film-forming film may be cured at an appropriate timing according to the type of the second protective film-forming film to form the second protective film. The picked-up semiconductor chip is flip-chip mounted on a wiring board, and finally constitutes a semiconductor device.

By using the first protective film forming sheet of the present invention, at the stage where this sheet is attached to the bump forming surface of the semiconductor wafer, at least the upper part of the bump penetrates the thermosetting resin film and protrudes, and at the upper part of the bump. The residual thermosetting resin film is suppressed. As a result, at least the upper part of the bump penetrates the first protective film and protrudes. When a semiconductor chip provided with such a first protective film and bumps is flip-chip mounted on a wiring board, the electrical connection between the semiconductor chip and the wiring board becomes good.
Hereinafter, the process from the bonding of the first protective film forming sheet of the present invention to the bump forming surface of the semiconductor wafer to the formation of the first protective film will be described in more detail with reference to the drawings.

FIG. 2 is a cross-sectional view schematically showing an example of how to use the first protective film forming sheet 1 shown in FIG.
When the first protective film forming sheet 1 is used, first, as shown in FIG. 2A, the first protective film forming sheet 1 is provided with the thermosetting resin film 12 on the bump forming surface 9a of the semiconductor wafer 9. Arrange so as to face each other.

The height of the bump 91 is not particularly limited, but is preferably 120 to 300 μm, more preferably 150 to 270 μm, and particularly preferably 180 to 240 μm. When the height of the bump 91 is equal to or higher than the lower limit value, the function of the bump 91 can be further improved. Further, when the height of the bump 91 is not more than the upper limit value, the effect of suppressing the remaining of the thermosetting resin film 12 on the upper portion of the bump 91 becomes higher.
In the present specification, the "bump height" means the height of the bump at the highest position from the bump forming surface.

The width of the bump 91 is not particularly limited, but is preferably 170 to 350 μm, more preferably 200 to 320 μm, and particularly preferably 230 to 290 μm. When the width of the bump 91 is equal to or larger than the lower limit value, the function of the bump 91 can be further improved. Further, when the height of the bump 91 is not more than the upper limit value, the effect of suppressing the remaining of the thermosetting resin film 12 on the upper portion of the bump 91 becomes higher.
In the present specification, the "bump width" is obtained by connecting two different points on the bump surface with a straight line when the bump is viewed in a plan view from a direction perpendicular to the bump forming surface. It means the maximum value of the line segment.

The distance between the adjacent bumps 91 is not particularly limited, but is preferably 250 to 800 μm, more preferably 300 to 600 μm, and particularly preferably 350 to 500 μm. When the distance is equal to or greater than the lower limit value, the function of the bump 91 can be further improved. Further, when the distance is not more than the upper limit value, the effect of suppressing the remaining of the thermosetting resin film 12 on the upper part of the bump 91 becomes higher.
In the present specification, the "distance between adjacent bumps" means the minimum value of the distance between the surfaces of adjacent bumps.

Next, the thermosetting resin film 12 is brought into contact with the bump 91 on the semiconductor wafer 9 and the first protective film forming sheet 1 is pressed against the semiconductor wafer 9. As a result, the first surface 12a of the thermosetting resin film 12 is sequentially crimped to the surface 91a of the bump 91 and the bump forming surface 9a of the semiconductor wafer 9. At this time, by heating the thermosetting resin film 12, the thermosetting resin film 12 softens, spreads between the bumps 91 so as to cover the bumps 91, adheres to the bump forming surface 9a, and forms the bumps 91. The bump 91 is embedded by covering the surface 91a, particularly the surface 91a in the vicinity of the bump forming surface 9a.
As described above, as shown in FIG. 2B, the thermosetting resin film 12 of the first protective film forming sheet 1 is attached to the bump forming surface 9a of the semiconductor wafer 9.

As described above, as a method of crimping the first protective film forming sheet 1 to the semiconductor wafer 9, a known method of crimping and attaching various sheets to an object can be applied, for example, a method using a laminate roller or the like. Can be mentioned.

The heating temperature of the first protective film forming sheet 1 when crimped to the semiconductor wafer 9 may be 80 to 100 ° C. as long as the curing of the thermosetting resin film 12 does not proceed at all or excessively. It is preferably 85 to 95 ° C., and more preferably 85 to 95 ° C.

The pressure at which the first protective film forming sheet 1 is pressed against the semiconductor wafer 9 is not particularly limited, but is preferably 0.1 to 1.5 MPa, more preferably 0.3 to 1 MPa.

As described above, when the first protective film forming sheet 1 is pressed against the semiconductor wafer 9, the thermosetting resin film 12 and the buffer layer 13 in the first protective film forming sheet 1 apply pressure from the bumps 91. Initially, the first surface 12a of the thermosetting resin film 12 and the first surface 13a of the buffer layer 13 are deformed in a concave shape. Then, the thermosetting resin film 12 to which the pressure is applied from the bump 91 as it is is torn. Finally, when the first surface 12a of the thermosetting resin film 12 is pressed against the bump forming surface 9a of the semiconductor wafer 9, the upper portion 910 of the bump 91 penetrates the thermosetting resin film 12 and protrudes. It becomes. In this final stage, the upper portion 910 of the bump 91 usually does not penetrate the buffer layer 13. This is because the buffer layer 13 has a buffering action against the pressure applied from the bump 91.

As shown in FIG. 2B, when the first protective film forming sheet 1 is attached to the bump forming surface 9a of the semiconductor wafer 9, the thermosetting resin film 12 is completely or almost on the upper portion 910 of the bump 91. Does not remain. In the present specification, "almost no thermosetting resin film remains on the upper part of the bump" means that a small amount of the thermosetting resin film remains on the upper part of the bump unless otherwise specified. It means that the amount does not interfere with the electrical connection between the semiconductor chip and the wiring board when the semiconductor chip provided with the bump is flip-chip mounted on the wiring board.

As described above, in the upper part 910 of the bump 91, the residual thermosetting resin film 12 can be suppressed when the thermosetting resin film 12 is deformed by applying pressure from the bump 91 as described above. This is because the curable resin film 12 is designed to be particularly easily torn.

After the first protective film forming sheet 1 was attached to the bump forming surface 9a of the semiconductor wafer 9, the surface (back surface) 9b of the semiconductor wafer 9 opposite to the bump forming surface 9a was further ground, if necessary. After that, a second protective film forming sheet (not shown) is attached to the back surface 9b.
Next, as shown in FIG. 2C, the first base material 11 and the cushioning layer 13 are peeled off from the thermosetting resin film 12.
Next, by curing the thermosetting resin film 12, as shown in FIG. 2D, the first protective film 12'is formed on the bump forming surface 9a.

When the first protective film 12'is formed on the bump forming surface 9a by using the thermosetting resin film 12 of the present invention and the first protective film forming sheet 1 provided with the same, the thermosetting before the thermosetting is performed. When the temperature of the sex resin film 12 is raised at 10 ° C./min, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is 500 Pa · s or more, which is shown in FIGS. 3 (c) and 3 (d). As described above, there is no possibility that cissing occurs and a defect that the exposed surface 9ao of the semiconductor wafer appears appears.

One aspect of the present invention is that the composition for forming a resin layer is represented by polyvinyl butyral (formulas (i) -1, (i) -2 and (i) -3 described above as the polymer component (A)). Content: 5 to 85% by mass, more preferably 5 to 50% by mass, still more preferably 5 to 20% by mass, based on the total solid content of the resin layer forming composition. As the thermosetting component (B), the epoxy resin (B1) (liquid bisphenol A type epoxy resin, epoxy equivalent 404 to 412 g / eq, content: 20 with respect to the total solid content of the resin layer forming composition). ~ 40% by mass, more preferably 25 to 35% by mass) of the thermosetting agent (B2) (novolac type phenol resin, content: 10 to 20% by mass with respect to the total solid content of the resin layer forming composition. %, More preferably 13 to 17% by mass); as the curing accelerator (C), 2-phenyl-4,5-dihydroxymethylimidazole (content: relative to the total solid content of the resin layer forming composition). 0.05 to 2% by mass, more preferably 0.1 to 1% by mass); as a filler (D), spherical silica modified with an epoxy group (average particle size 0.05 μm, content: resin layer) It contains 3 to 60% by mass, more preferably 3 to 55% by mass, still more preferably 5 to 10% by mass based on the total solid content of the forming composition (however, the total content of each component is , 100% by mass based on the total solid content of the resin layer forming composition).
Another aspect of the present invention is that the composition for forming a resin layer is represented by polyvinyl butyral (formulas (i) -1, (i) -2 and (i) -3 described above as the polymer component (A)). Content: 5 to 85% by mass, more preferably 5 to 50% by mass, still more preferably 5 to 20% by mass, based on the total solid content of the resin layer forming composition. As the thermosetting component (B), the epoxy resin (B1) (dicyclopentadiene type epoxy resin, epoxy equivalent 254 to 264 g / eq, content: 10 with respect to the total solid content of the resin layer forming composition). ~ 30% by mass, more preferably 15 to 25% by mass) of the thermosetting agent (B2) (novolac type phenol resin, content: 10 to 20% by mass with respect to the total solid content of the resin layer forming composition. %, More preferably 13 to 17% by mass); as the curing accelerator (C), 2-phenyl-4,5-dihydroxymethylimidazole (content: relative to the total mass of the solid content of the resin layer forming composition). 0.05 to 2% by mass, more preferably 0.1 to 1% by mass); as a filler (D), spherical silica modified with an epoxy group (average particle size 0.05 μm, content: resin layer) It contains 3 to 60% by mass, more preferably 3 to 55% by mass, still more preferably 5 to 10% by mass based on the total solid content of the forming composition (however, the total content of each component is , 100% by mass with respect to the total solid content of the resin layer forming composition).
In yet another aspect of the present invention, the composition for forming a resin layer is represented by polyvinyl butyral (described in the above formulas (i) -1, (i) -2 and (i) -3) as the polymer component (A). Content: 5 to 85% by mass, more preferably 5 to 50% by mass, still more preferably 5 to 20% by mass, based on the total solid content of the resin layer forming composition. As the thermosetting component (B), the epoxy resin (B1) (liquid bisphenol A type epoxy resin (epoxy equivalent 404 to 412 g / eq, content: relative to the total solid content of the resin layer forming composition) 20 to 40% by mass, more preferably 25 to 35% by mass) and a dicyclopentadiene type epoxy resin (epoxy equivalent 254 to 264 g / eq, content: 10 with respect to the total solid content of the resin layer forming composition. ~ 30% by mass, more preferably 15 to 25% by mass)) with a thermosetting agent (B2) (novolac type phenol resin, content: 10 to 10% based on the total solid content of the resin layer forming composition. 20% by mass, more preferably 13 to 17% by mass); as the curing accelerator (C), 2-phenyl-4,5-dihydroxymethylimidazole (content: total mass of solid content of the resin layer forming composition) 0.05 to 2% by mass, more preferably 0.1 to 1% by mass); as a filler (D), an epoxy group-modified spherical silica (average particle size 0.05 μm, content: It contains 3 to 60% by mass, more preferably 3 to 55% by mass, still more preferably 5 to 10% by mass based on the total solid content of the resin layer forming composition (however, the content of each component). The total does not exceed 100% by mass with respect to the total solid content of the resin layer forming composition).

One aspect of the present invention includes a thermosetting resin film (thickness: 1 to 100 μm, more preferably 5 to 75 μm, particularly preferably 5 to 50 μm) formed by forming the above resin layer forming composition.
Another aspect of the present invention includes a first protective film forming sheet provided with the thermosetting resin film on one surface of the first support sheet.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

The components used in the production of the composition for forming a thermosetting resin film are shown below.
-Polymer component (A)
Polymer component (A) -1: Polyvinyl butyral having a structural unit represented by the following formulas (i) -1, (i) -2 and (i) -3 (Sekisui Chemical Co., Ltd. "Eslek (registered trademark)" B BL-10 ”, weight average molecular weight 25,000, glass transition temperature 59 ° C. In the formula, l ₁ is 68 to 74 mol%, m ₁ is ₁ to 3 mol%, and n ₁ is about 28 mol%. .)

Polymer component (A) -2: Polyvinyl butyral having a structural unit represented by the following formulas (i) -1, (i) -2 and (i) -3 (Sekisui Chemical Co., Ltd. "Eslek (registered trademark)) B BL-1 ”, weight average molecular weight 30,000, glass transition temperature 66 ° C. In the formula, l ₁ is 60 to 66 mol%, m ₁ is ₁ to 3 mol%, and n ₁ is about 36 mol%. .)

Polymer component (A) -3: Polyvinyl butyral having a structural unit represented by the following formulas (i) -1, (i) -2 and (i) -3 (Sekisui Chemical Co., Ltd. "Eslek (registered trademark)" SV-02 ”, weight average molecular weight 50,000, glass transition temperature 59 ° C., n ₁ is about 22 mol% in the formula.)

Polymer component (A) -4: Polyvinyl butyral having a structural unit represented by the following formulas (i) -1, (i) -2 and (i) -3 (Sekisui Chemical Co., Ltd. "Eslek (registered trademark)" B BM-S ”, weight average molecular weight 66,000, glass transition temperature 60 ° C. In the formula, l ₁ is 70 to 76 mol%, m ₁ is 4 to 6 mol%, and n ₁ is about 22 mol%. .)

In the formula, l ₁ , m ₁ and n ₁ are the content ratios (mol%) of the respective constituent units.

-Thermosetting component (B)
Epoxy resin (B1) -1: Liquid bisphenol A type epoxy resin ("EPICLON (registered trademark) EXA-4850-1000" manufactured by DIC Corporation, epoxy equivalent 404 to 412 g / eq)
Epoxy resin (B1) -2: Dicyclopentadiene type epoxy resin ("EPICLON (registered trademark) HP-7200" manufactured by DIC Corporation, epoxy equivalent 254 to 264 g / eq)
Thermosetting agent (B2) -1: Novolac type phenolic resin (Showa Denko "Shonol (registered trademark) BRG-556")

・ Curing accelerator (C)
Curing accelerator (C) -1: 2-phenyl-4,5-dihydroxymethylimidazole ("Curesol (registered trademark) 2PHZ" manufactured by Shikoku Chemicals Corporation)
・ Filler (D)
Filler (D) -1: Spherical silica modified with an epoxy group ("Admanano (registered trademark) YA050C-MKK" manufactured by Admatex, average particle size 0.05 μm)

[Example 1]
<Manufacturing of thermosetting resin film>
(Manufacture of composition for forming thermosetting resin film)
Polymer component (A) -1, epoxy resin (B1) -1, epoxy resin (B1) -2, thermosetting agent (B2) -1, curing accelerator (C) -1, and filler (D)- 1 is dissolved or dispersed in methyl ethyl ketone so that the ratio of these contents becomes the value shown in Table 1, and the mixture is stirred at 23 ° C. to obtain a solid content concentration as a composition for forming a thermosetting resin film. A composition for forming a resin layer having a weight of 55% by mass was obtained. In addition, the description of "-" in the column of the contained component in Table 1 means that the composition for forming a thermosetting resin film does not contain the component.

(Manufacturing of thermosetting resin film)
The composition for forming a thermosetting resin film obtained above on the peeled surface of a peeled film (“SP-PET38131” manufactured by Lintec, 38 μm thick) in which one side of a polyethylene terephthalate film was peeled by a silicone treatment. The material was coated and dried by heating at 120 ° C. for 2 minutes to obtain a thermosetting resin film having a thickness of 30 μm.
The thickness of the thermosetting resin film was measured using a contact-type thickness gauge (manufactured by Teclock Co., Ltd., product name "PG-02").

<Evaluation of minimum shear viscosity of thermosetting resin film>
Next, a plurality of the thermosetting resin films were laminated to form a thermosetting resin film having a thickness of 500 μm. From this, a cylindrical evaluation sample having a diameter of 25 mm and a thickness of 500 μm was prepared, and this sample was placed in a shear viscosity measuring device. At this time, the sample was placed on the installation location of the measuring device, and the sample was fixed and installed at the installation location by pressing the measuring jig from the upper surface of the sample.
The shear viscosity from room temperature to 150 ° C. was measured every second under the measurement conditions of frequency: 1 Hz, heating rate and 10 ° C./min. The measurement results are shown in FIG. Then, the minimum value of the shear viscosity at 90 ° C. to 130 ° C. was determined.

<Manufacturing of first protective film forming sheet>
Next, a sticking tape (“E-8510HR” manufactured by Lintec Corporation) is used as the first support sheet, and the thermosetting resin film on the above-mentioned release film is stuck to the sticking target layer of the sticking tape. A first protective film forming sheet having the structure shown in FIG. 1 was obtained in which a support sheet, a thermosetting resin film, and a release film were laminated in this order in the thickness direction thereof.

<Hajiki evaluation>
In the first protective film forming sheet obtained above, the release film is removed, and the surface (exposed surface) of the thermosetting resin film exposed thereby is pressed against the bump forming surface of the 8-inch φ bump wafer. A first protective film forming sheet was attached to the bump forming surface of the semiconductor wafer. At this time, the first protective film forming sheet is attached using a pasting device (roller type laminator, Lintec Corporation "RAD-3510 F / 12") at a table temperature of 90 ° C., a sticking speed of 2 mm / sec, and a sticking pressure. This was performed while heating the thermosetting resin film under the condition of 0.5 MPa. As the 8-inch φ bump wafer, a 0.4 mm phi BGA semiconductor wafer (Walts WLPTEGM2) having a bump height of 210 μm, a bump width of 250 μm, and a distance between adjacent bumps of 400 μm is used. There was.
As described above, a laminated structure (1) was obtained in which a first protective film forming sheet was attached to a bump forming surface of a semiconductor wafer.

Then, after irradiating with ultraviolet rays and peeling off the sticking tape part (lintec, RAD-2700), the wafer to which the thermosetting resin film is stuck is heated in a pressure oven (lintec RAD-9100). The thermosetting resin film was heat-cured by heat treatment under heating conditions of 130 ° C., time: 2 hours, and oven pressure: 0.5 MPa.
After thermosetting, the bump surface is scanned with a digital microscope, and a sample having a visible point on the surface of the semiconductor wafer is evaluated as "yes", and a sample without a visible point on the surface of the semiconductor wafer is evaluated as "absent". And said.

[Examples 2 to 8, Comparative Example 1]
<Manufacturing and evaluation of thermosetting resin film>
Same as Example 1 except that one or both of the types and content ratios of each component were set as shown in Tables 1 and 2 during the production of the composition for forming a thermosetting resin film. A thermosetting resin film and a sheet for forming a first protective film were produced by the method, and the minimum shear viscosity and cissing of the thermosetting resin film were evaluated. The results are shown in Table 1, Table 2 and FIG.

From the results shown in Tables 1 and 2, the exposed surface 9ao appears on the semiconductor wafer in the thermosetting resin films of Examples 1 to 8 in which the minimum value of the shear viscosity at 90 ° C. to 130 ° C. is 500 Pa · s or more. No defects occurred and no shears occurred.

INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing a semiconductor chip or the like having a bump on a connection pad portion used in a flip chip mounting method.

1 ... 1st protective film forming sheet, 11 ... 1st base material, 11a ... 1st surface of 1st base material, 12 ... Thermosetting resin film, 12a ... Thermosetting First surface of the sex resin film, 12'... first protective film, 13 ... buffer layer, 13a ... first surface of the buffer layer, 101 ... first support sheet, 9 ... semiconductor Wafer, 9a ... semiconductor wafer bump forming surface, 9ao ... semiconductor wafer exposed surface, 91 ... bump, 91a ... bump surface, 910 ... upper part of bump

Claims (4)

A thermosetting resin film for forming a first protective film on the surface by sticking to a surface having bumps of a semiconductor wafer and thermosetting the surface, and the thermosetting resin film before thermosetting is 10 A thermosetting resin film having a minimum shear viscosity of 500 Pa · s or more at 90 ° C. to 130 ° C. when the temperature is raised at ° C./min. The thermosetting resin film according to claim 1, which contains a polymer component (A) and a thermosetting component (B). The thermosetting resin film according to claim 1 or 2, which contains polyvinyl acetal. A sheet for forming a first protective film, wherein the thermosetting resin film according to any one of claims 1 to 3 is provided on one surface of the first support sheet.

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