JP6777834B1 - Method for manufacturing thermosetting protective film forming film, protective film forming composite sheet, and chip - Google Patents

Abstract

A film for forming a thermosetting protective film, which is thermosetting and has a storage elastic modulus E'of 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower.

Description

The present invention relates to a method for producing a thermosetting protective film forming film, a protective film forming composite sheet, and a chip.
The present application claims priority based on Japanese Patent Application No. 2018-219635 filed in Japan on November 22, 2018, the contents of which are incorporated herein by reference.

In recent years, semiconductor devices to which a mounting method called a so-called face down method has been applied have been manufactured. In the face-down method, a semiconductor chip having an electrode such as a bump on the circuit surface is used, and the electrode is bonded to the substrate. Therefore, the back surface of the semiconductor chip opposite to the circuit surface may be exposed.

A resin film containing an organic material is formed as a protective film on the back surface of the exposed semiconductor chip, and may be incorporated into a semiconductor device as a semiconductor chip with a protective film.
The protective film is used to prevent cracks from occurring in the semiconductor chip after the dicing process or packaging.

In order to form such a protective film, for example, a protective film forming composite sheet comprising a support sheet and a protective film forming film for forming the protective film on the support sheet is used. Will be done. The protective film-forming film can form a protective film by curing. Further, the support sheet can be used to fix the semiconductor wafer when the protective film forming film or the semiconductor wafer provided with the protective film on the back surface is divided into semiconductor chips. Further, the support sheet can also be used as a dicing sheet. The protective film-forming composite sheet including the support sheet and the protective film-forming film can also be used as an integrated protective film-forming film and dicing sheet (see Patent Document 1).

On the other hand, as a method for obtaining a semiconductor chip, a method of dicing a semiconductor wafer using a dicing blade is widely used. In this method, a semiconductor chip is usually obtained by dividing a semiconductor wafer having a protective film forming film or a protective film on the back surface by a dicing blade together with the protective film forming film or the protective film and separating them into individual pieces. ..

On the other hand, in recent years, various methods for dividing semiconductor wafers without using a dicing blade have been studied. For example, by irradiating a laser beam so as to focus on a focal point set inside the semiconductor wafer, a modified layer is formed inside the semiconductor wafer, and then this modified layer is formed and on the back surface. By expanding the semiconductor wafer to which the resin film is attached in the surface direction of the resin film together with the resin film, the resin film is cut, and the semiconductor wafer is divided and individualized at the site of the modified layer. A method for obtaining a semiconductor chip is known. If the resin film is expanded in the plane direction under normal temperature conditions, the resin film may be poorly divided. Therefore, in order to divide the resin film well together with the semiconductor wafer, for example, at -15 ° C. Cool expansion is being considered under low temperature conditions.

Unlike the method using a dicing blade, the division method using a cool expand does not involve the formation of a cutting portion by the dicing blade in the semiconductor wafer, more semiconductor chips can be obtained from the semiconductor wafer, and no cutting chips are generated. It has the advantage of.

Japanese Unexamined Patent Publication No. 2016-027655

However, after expanding the protective film-forming composite sheet provided with the heat-curable protective film-forming film (see "Division step" of the method for producing a chip with a protective film described later), the heat-curable protective film-forming film is formed. When the chip with a protective film is manufactured by heat curing (see "Protective film forming step" in the method for manufacturing a chip with a protective film described later), the surface in contact with the support sheet of the protective film is ring-shaped and has a height of several hundred nanometers. There was a problem that a degree of excitement (hereinafter referred to as "center mark") occurred. The center mark formed on the protective film is formed at the center of each chip.

The present invention provides a thermosetting protective film forming film in which the generation of center marks in the protective film is suppressed even when the protective film is formed through the protective film forming step after the dividing step. The purpose.
Another object of the present invention is to provide a protective film-forming composite sheet provided with the thermosetting protective film-forming film on the support sheet.
Another object of the present invention is to provide a method for manufacturing a chip with a protective film using the thermosetting protective film forming film.

As a result of diligent studies by the present inventors in order to solve the above problems, for protective film formation at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower, which can be the heat treatment temperature for heat treatment in the protective film forming step. It has been found that the generation of center marks can be suppressed by setting the storage elastic modulus of the film to 2 MPa or more.
That is, as one aspect of the present invention, the following methods for producing a thermosetting protective film forming film, a protective film forming composite sheet, and a chip with a protective film are provided.

(1) A film for forming a thermosetting protective film, which is used by being attached to the back surface of a wafer or a chip .
At all temperatures in the temperature range of 80 ° C. or higher 130 ° C. or less, measured at a tension mode, the storage modulus before thermal curing E 'is Ri der least 2 MPa,
At all temperatures in the temperature range of less than 80 ° C. 23 ° C. or higher were measured at a tensile mode, storage elastic modulus before thermal curing E 'is Ru der least 5 MPa, thermosetting protective film forming film.
(2) The thermosetting according to (1) above, wherein the storage elastic modulus E'before thermosetting measured in the tensile mode is 3000 MPa or less at all temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C. A film for forming a sex protective film.
(3) A film for forming a thermosetting protective film, which is used by being attached to the back surface of a wafer or a chip .
At all temperatures in the temperature range of 80 ° C. or higher 130 ° C. or less, measured at a tension mode, the storage modulus before thermal curing E 'is Ri der least 2 MPa,
At 0 all temperatures temperature range below ° C. or higher 23 ° C., was measured at a tension mode, the storage modulus before thermal curing E 'is Ru der less 3000 MPa, thermosetting protective film forming film.
( 4 ) The protective film forming film has a polymer component (A) having a structural unit containing a functional group (a1) and two or more functional groups (f1) that react with the functional group (a1). The film for forming a thermosetting protective film according to any one of (1) to (3) above, which contains a cross-linking agent (F).
( 5 ) The thermosetting protection according to ( 4 ) above, wherein the content of the structural unit containing the functional group (a1) is 3 parts by mass or more with respect to 100 parts by mass of the polymer component (A). Film for film formation.
( 6 ) The thermosetting protection according to (4) or (5) above, wherein the content of the functional group (f1) is 0.005 to 4 equivalents with respect to 1 equivalent of the functional group (a1). Film for film formation.
( 7 ) The thermosetting protective film forming film according to any one of (4) to (6 ) above, wherein the functional group (f1) is an isocyanate group and the functional group (a1) is a hydroxyl group. ..
(8) The storage elastic modulus E'(E'(80) of the protective film forming film before thermosetting was measured in a tensile mode at any temperature in the temperature range of 80.0 to 80.5 ° C. )) Is the ratio of the storage elastic modulus E'(E'(130)) before thermosetting measured in the tensile mode at any temperature in the temperature range of 129.5 to 130.0 ° C. , The thermosetting protective film forming film according to any one of (1) to (7) above, wherein the value of E'(80) / E'(130) is 0.3 to 3.
(9) The film for forming a thermosetting protective film according to any one of (1) to (8) above, which has a thickness of 1 to 100 μm.
(10) The protective film forming film contains a polymer component (A) and a thermosetting component (B).
The polymer component (A) is an acrylic resin.
The thermosetting according to any one of (1) to (9) above, wherein the thermosetting component (B) is an epoxy-based thermosetting resin composed of an epoxy resin (B1) and a thermosetting agent (B2). A film for forming a sex protective film.
(11) The support sheet and the thermosetting protective film forming film according to any one of (1) to (10) above are provided.
A composite sheet for forming a protective film, wherein the film for forming a thermosetting protective film is provided on the support sheet.
(12) Formation of a thermosetting protective film in the thermosetting protective film forming film according to any one of (1) to (10) above, or the protective film forming composite sheet according to (11) above. The process of forming a laminate by attaching a film for use to the back surface of a wafer or chip , and
By expanding the laminate at a temperature of less than 23 ° C., the wafer and the thermosetting protective film forming film are divided, or the thermosetting protective film forming film attached to the chip is divided. Process and
A method for producing a chip with a protective film, comprising a step of forming a protective film on the chip by heat-curing the divided film for forming a thermosetting protective film.
(13) The wafer is obtained by irradiating the inside of the wafer with laser light to form a modified layer inside the wafer.
The step of dividing the thermosetting protective film forming film expands the wafer on which the modified layer is formed together with the thermosetting protective film forming film toward the surface of the protective film forming film. The method for producing a chip with a protective film according to (12), wherein the step is a step of cutting the film for forming a thermosetting protective film and dividing the wafer at a portion of the modified layer.

According to the present invention, even when the protective film is formed through the protective film forming step after the dividing step, the heat-curable protective film forming film in which the generation of the center mark in the protective film is suppressed, the thermal curing thereof. Provided are a composite sheet for forming a protective film provided with a film for forming a sex protective film, and a method for producing a chip using the film for forming the protective film.

It is sectional drawing which shows typically an example of the film for forming a protective film which concerns on one Embodiment of this invention. It is sectional drawing which shows typically an example of the composite sheet for forming a protective film which concerns on one Embodiment of this invention. It is sectional drawing which shows another example schematically of the composite sheet for forming a protective film which concerns on one Embodiment of this invention. It is sectional drawing which shows typically an example of the manufacturing method of the chip with a protective film which concerns on one Embodiment of this invention. It is a schematic diagram of the observation image acquired by the optical interference type surface roughness meter of the center mark confirmed on the protective film obtained by curing the protective film forming film of the comparative example.

-Film for forming a thermosetting protective film The film for forming a thermosetting protective film according to an embodiment of the present invention is thermosetting and has a storage elastic modulus at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower. The rate E'is 2 MPa or more.
As will be described later, by providing the thermosetting protective film forming film on the support sheet, the protective film forming composite sheet can be formed.
Hereinafter, the film for forming a thermosetting protective film according to an embodiment of the present invention is also simply referred to as "a film for forming a thermosetting protective film" or "a film for forming a protective film".

The film for forming a protective film is thermosetting. As used herein, the term "thermosetting" means the property of being cured by applying heat.
The protective film-forming film is cured by heat treatment to become a protective film. This protective film can be used to protect the back surface of the wafer or chip (the surface opposite to the electrode forming surface).
The protective film-forming film tends to be soft and can be easily attached to the object to be attached.
Examples of the wafer or chip include a semiconductor wafer or a semiconductor chip, an insulator wafer or an insulator chip, a conductor wafer or a conductor chip, and the like. Examples of the insulator wafer include, but are not limited to, glass wafers and sapphire wafers. In the following embodiments, a case where a semiconductor wafer or a semiconductor chip is used as the wafer or chip may be described.

In the present specification, the "thermosetting protective film forming film" means a film before thermosetting, and the "protective film" means a cured product obtained by thermosetting the thermosetting protective film forming film. ..

In the present specification, "normal temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ° C.
As used herein, the term "cool expand" refers to applying a force that expands in a direction parallel to the surface of a wafer at a temperature lower than room temperature.
The temperature at which the cool expand is carried out may be less than 23 ° C. or less than 15 ° C.

When the protective film-forming film has a storage elastic modulus E'of 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower, so that the protective film is formed by heat curing after expansion. Even if there is, the generation of the central mark on the protective film can be suppressed. When the storage elastic modulus E'is less than 2 MPa, a center mark may be generated in the protective film. From the viewpoint of making it possible to more preferably suppress the generation of center marks, the protective film forming film has a storage elastic modulus E'of 3 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower. It is preferably 3.5 MPa or more, more preferably 4 MPa or more, further preferably 5 MPa or more, and particularly preferably 5.5 MPa or more.
The upper limit of the storage elastic modulus E'at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower of the protective film forming film is not particularly limited, but may be 100 MPa or lower, for example. , 80 MPa or less, or 20 MPa or less.
The storage elastic modulus E'of the protective film forming film at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower may be, for example, 3 MPa or more and 100 MPa or less, or 3.5 MPa or more and 100 MPa or less. It may be 4 MPa or more and 80 MPa or less, 5 MPa or more and 20 MPa or less, or 5.5 MPa or more and 20 MPa or less. The upper limit value and the lower limit value of the numerical range of the storage elastic modulus E'exemplified above can be freely combined.

Here, the above temperature range of 80 ° C. or higher and 130 ° C. or lower may correspond to the heat treatment temperature for thermosetting the protective film forming film in the protective film forming step described later. The protective film forming step will be described in detail in the method for manufacturing a chip with a protective film, which will be described later.

Considering that the protective film forming film tends to have a storage elastic modulus E'decreasing at a high temperature, all the temperatures in the above temperature range of 80 ° C. or higher and 130 ° C. or lower are in the temperature range of 100 ° C. or higher and 130 ° C. or lower. It is preferable that all temperatures are in the temperature range of 120 ° C. or higher and 130 ° C. or lower.

The storage elastic modulus E'of the protective film forming film can be measured as follows, as shown in Examples described later.
16 layers of a protective film forming film having a thickness of 15 μm are laminated to obtain a laminated body having a width of 4 mm, a length of 22 mm, and a thickness of 240 μm, which is used as a measurement sample of the protective film forming film. The storage elastic modulus E'is determined by using a dynamic viscoelastic automatic measuring device (for example, Leovibron DDV-01FP manufactured by A & D Co., Ltd.) with respect to the above-mentioned measurement sample by a tensile method (tensile mode) and between chucks. Distance: 20 mm, frequency: 11 Hz, heating rate: 3 ° C / min, storage elastic modulus E'(for example, from -10 ° C) in a temperature range including a desired temperature or temperature range under the measurement conditions of constant rate temperature rise. The storage elastic modulus E') up to 140 ° C. is measured.
The storage elastic modulus E'of the protective film forming film, whether completely or partially, is not heat-cured (that is, the protective film forming film is heated after being formed and, if necessary, dried). The value obtained for the protective film forming film (not exposed to the curing temperature) is used as the measurement target.

The protective film forming film has a storage elastic modulus E'(E'(80)) at any temperature in the temperature range of 80.0 to 80.5 ° C. and a temperature range of 129.5 to 130.0 ° C. The value of E'(80) / E'(130), which is the ratio to the storage elastic modulus E'(E'(130)) at any of the temperatures, is preferably 0.3 to 3. It is more preferably 0.5 to 2, and more preferably 1 to 1.2. The protective film forming film having such characteristics can be said to be a high quality protective film forming film having high stability of storage elastic modulus E'in a high temperature range of 80 ° C. or higher and 130 ° C. or lower. Further, the protective film forming film having such characteristics does not cause a rapid decrease in the storage elastic modulus E'in the process of raising the temperature, so that the generation of the central mark can be suppressed more effectively.

The thermosetting protective film forming film according to one embodiment of the present invention preferably has a storage elastic modulus E'of 5 MPa or more and 5 MPa or more and 3000 MPa at all temperatures in the temperature range of 23 ° C. or higher and lower than 80 ° C. It is preferably 5.1 MPa or more and 3000 MPa or less, more preferably 5.1 MPa or more and 1000 MPa or less, further preferably 5.2 MPa or more and 400 MPa or less, and 5.3 MPa or more. It is particularly preferably 300 MPa or less. The upper limit value and the lower limit value of the numerical range of the storage elastic modulus E'exemplified above can be freely combined.

The temperature range of 23 ° C. or higher and lower than 80 ° C. may correspond to the temperature at which the protective film forming film is attached to the wafer or chip in the attachment step described later. The sticking step will be described in detail in the method for manufacturing a chip with a protective film, which will be described later. When the storage elastic modulus E'of the thermosetting protective film forming film is at least the above lower limit value, the fluidity of the protective film forming film after the wafer or the like is attached to the thermosetting protective film forming film. If it is too high, it can be further prevented from seeping out (bleeding out) from the end of the wafer or chip. Further, when the storage elastic modulus E'of the film for forming a thermosetting protective film is not more than the above upper limit value, the adhesion to a wafer or the like can be improved.

The thermosetting protective film forming film according to one embodiment of the present invention preferably has a storage elastic modulus E'of 3000 MPa or less, and 100 MPa or more and 3000 MPa at all temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C. It is preferably 100 MPa or more and 2800 MPa or less, more preferably 100 MPa or more. The upper limit value and the lower limit value of the numerical range of the storage elastic modulus E'exemplified above can be freely combined.

The temperature range of 0 ° C. or higher and lower than 23 ° C. may correspond to the temperature at which the protective film forming film is expanded in the division step described later. The dividing step will be described in detail in the method for manufacturing a chip with a protective film, which will be described later. When the storage elastic modulus E'of the thermosetting protective film forming film is not more than the above upper limit value, the breaking strength of the protective film forming film in the dividing step does not become excessive, and it is easily applied by the force applied at the time of expansion. Since it is split, the splittability can be improved. When the storage elastic modulus E'of the thermosetting protective film forming film is equal to or more than the above lower limit value, the protective film forming film does not stretch excessively in the dividing step and is easily stretched by the force applied by the expand. Since it is divided into two parts, the splittability can be improved.
Considering that the temperature range of 0 ° C. or higher and lower than 23 ° C. corresponds to the temperature condition of Cool Expand (CE) performed at a temperature lower than room temperature, all of the above temperature ranges of 0 ° C. or higher and lower than 23 ° C. The temperature of may be any temperature in the temperature range of 0 ° C. or higher and lower than 15 ° C.

The storage elastic modulus E'can be adjusted by, for example, adjusting the type of the component contained in the protective film forming film such as the cross-linking agent (F) and the content thereof.

FIG. 1 is a cross-sectional view schematically showing an example of a protective film forming film according to an embodiment 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 protective film forming film 13 shown here includes a first release film 151 on one surface (sometimes referred to as a “first surface” in the present specification) 13a, and the first surface 13a Provided a second release film 152 on the other side (sometimes referred to as the "second side" in the present specification) 13b on the opposite side.
Such a protective film forming film 13 is suitable for storage, for example, in the form of a roll.
In the protective film forming film according to the embodiment of the present invention, the first release film 151 and the second release film 152 are not essential configurations.

Both the first release film 151 and the second release film 152 may be known.
The first release film 151 and the second release film 152 may be the same as each other, or are different from each other, for example, the release forces required for peeling from the protective film forming film 13 are different from each other. You may.

In the protective film forming film 13 shown in FIG. 1, either one of the first release film 151 and the second release film 152 is removed, and the back surface of the semiconductor wafer (not shown) is attached to the generated exposed surface. Then, the other remaining of the first release film 151 and the second release film 152 is removed, and the generated exposed surface becomes a surface to be attached to the support sheet.

The thermosetting protective film forming film is thermosetting and undergoes thermosetting to finally become a protective film having high impact resistance. This protective film can prevent the occurrence of cracks in the semiconductor chip after the dividing step, for example.
The protective film forming film can be formed by using the thermosetting protective film forming composition described later.

The protective film forming film may have only one layer (single layer), may have two or more layers, and when there are a plurality of layers, the plurality of layers may be the same or different from each other, and the plurality of layers may be used. The combination is not particularly limited.
In the present specification, not only in the case of the protective film forming film, "a plurality of layers may be the same or different from each other" means "all layers may be the same or all layers". "The layers may be different, only some of the layers may be the same", and "plurality of layers is different from each other" means that "at least one of the constituent materials and thicknesses of each layer is different from each other". It means "different".

The thickness of the protective film forming film is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 75 μm, and particularly preferably 5 to 50 μm. When the thickness of the protective film forming film is at least the above lower limit value, the adhesive force to the wafer and the chip as the adherend becomes larger. Further, when the thickness of the protective film forming film is not more than the upper limit value, the protective film which is a cured product can be more easily cut by utilizing the shearing force at the time of cool expansion.
Here, the "thickness of the protective film forming film" means the thickness of the entire protective film forming film, and for example, the thickness of the protective film forming film composed of a plurality of layers means the protective film forming film. It means the total thickness of all the layers that make up.

In the present specification, the "thickness" can be obtained by using a constant pressure thickness measuring device according to JIS K7130 as a value represented by the average of the thickness measured at five randomly selected points.

The shape of the protective film forming film is not particularly limited, but the shape of the protective film forming film may be circular in consideration of being attached to a circular wafer. When the shape of the protective film forming film is circular, the diameter thereof may be, for example, 200 mm (for 8-inch wafer) or 300 mm (for 12-inch wafer).

Preferred films for forming a protective film include, for example, those containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be regarded as being formed by a polymerization reaction of a polymerizable compound. Further, the thermosetting component (B) is a component capable of undergoing a curing (polymerization) reaction by using heat as a trigger for the reaction. In the present specification, the polymerization reaction also includes a polycondensation reaction.

In the present specification, the adhesive force between the protective film obtained by curing the protective film forming film and the pressure-sensitive adhesive layer that the support sheet can have is preferably 30 to 2000 mN / 25 mm, preferably 40 to 40 to. It is more preferably 1700 mN / 25 mm, and particularly preferably 50 to 1500 mN / 25 mm. When the adhesive strength is at least the lower limit value, the pick-up of the chip with the protective film other than the intended one is suppressed at the time of picking up the chip with the protective film, and the target chip with the protective film can be picked up highly selectively. Further, when the adhesive strength is not more than the upper limit value, cracking and chipping of the chip are suppressed when the chip with the protective film is picked up. As described above, when the adhesive strength is within a specific range, the protective film forming composite sheet has good pick-up suitability.

The adhesive strength between the protective film and the pressure-sensitive adhesive layer can be measured by the following method.
That is, a protective film-forming composite sheet having a width of 25 mm and an arbitrary length is attached to the adherend by the protective film-forming film.
Next, the protective film-forming film is thermosetting to form the protective film, and then the support sheet is peeled off from the protective film attached to the adherend at a peeling speed of 300 mm / min. At this time, the support sheet is peeled off in the length direction (the length direction of the protective film forming composite sheet) so that the surfaces of the protective film and the adhesive layer that are in contact with each other form an angle of 180 °. It is peeled off, so-called 180 ° peeling. Then, the load (peeling force) at the time of this 180 ° peeling is measured, and the measured value is taken as the adhesive force (mN / 25 mm).

The length of the protective film-forming composite sheet to be used for measurement is not particularly limited as long as the adhesive force can be stably detected, but is preferably 100 to 300 mm. Further, at the time of measurement, it is preferable that the protective film-forming composite sheet is attached to the adherend to stabilize the attached state of the protective film-forming composite sheet.

In the present specification, the adhesive force between the protective film forming film and the pressure-sensitive adhesive layer is not particularly limited and may be, for example, 80 mN / 25 mm or more, but preferably 100 mN / 25 mm or more. , 150 mN / 25 mm or more is more preferable, and 200 mN / 25 mm or more is particularly preferable. When the adhesive force is 100 mN / 25 mm or more, peeling between the protective film forming film and the support sheet is suppressed during dicing, and for example, a chip having a protective film forming film on the back surface scatters from the support sheet. Is suppressed.

On the other hand, the upper limit of the adhesive force between the protective film forming film and the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, 4000 mN / 25 mm or less, 3000 mN / 25 mm or less, or 2000 mN. It may be / 25 mm or less. However, these are just examples.

The adhesive strength between the protective film forming film and the pressure-sensitive adhesive layer is the same as the adhesive strength between the protective film and the support sheet described above, except that the protective film forming film used for measurement is not thermoset. It can be measured in the same way.

The above-mentioned adhesive force between the protective film and the pressure-sensitive adhesive layer and the adhesive force between the protective film-forming film and the pressure-sensitive adhesive layer are, for example, the types and amounts of components contained in the protective film-forming film, and adhesion. It can be appropriately adjusted by adjusting the constituent material of the agent layer, the surface condition of the pressure-sensitive adhesive layer, and the like.

For example, the type and amount of the component contained in the protective film forming film can be adjusted by the type and amount of the component contained in the protective film forming composition described later. Then, among the components contained in the composition for forming a protective film, for example, by adjusting the type and content of the polymer having no energy ray-curable group, the content of the filler, or the content of the cross-linking agent. The adhesive force between the protective film or the protective film forming film and the support sheet can be adjusted more easily.

Further, for example, when the layer on which the protective film forming film is provided in the support sheet is an adhesive layer, the constituent material thereof can be appropriately adjusted by adjusting the type and amount of the components contained in the adhesive layer. .. The type and amount of the components contained in the pressure-sensitive adhesive layer can be adjusted by the type and amount of the components contained in the pressure-sensitive adhesive composition described above.
On the other hand, when the layer on which the protective film forming film is provided on the support sheet is a base material, the adhesive force between the protective film or the protective film forming film and the support sheet is not limited to the constituent materials of the base material. It can also be adjusted by the surface condition of the base material. Then, the surface condition of the base material is, for example, the surface treatment mentioned above as a substance for improving the adhesion with other layers of the base material, that is, a sandblasting treatment, an unevenness treatment by a solvent treatment or the like; It can be adjusted by performing any of electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment and other oxidation treatment; primer treatment and the like.

The film for forming a protective film is thermosetting and has energy ray curability, and may contain, for example, an energy ray curable component.
The protective film-forming film may be thermosetting and may not have energy ray curability.
The energy ray-curable component is preferably uncured, preferably sticky, and more preferably uncured and sticky.

The curing conditions when the protective film forming film is cured to form the protective film are appropriately determined according to the type of the protective film forming film, considering the degree of curing to the extent that the protective film fully exerts its function. You can select it.
The heating temperature for curing the protective film-forming film may be any temperature at which the protective film-forming film is thermosetting. The heating temperature can be exemplified by a temperature of 80 ° C. or higher and 130 ° C. or lower in the above-mentioned regulation of storage elastic modulus E', but is not limited to this, and may be a temperature equal to or higher than the thermosetting temperature of the protective film forming film, for example. It may be 80 ° C. or higher and 200 ° C. or lower, 100 ° C. or higher and 180 ° C. or lower, 110 ° C. or higher and 170 ° C. or lower, or 120 ° C. or higher and 130 ° C. or lower. The heating time for giving the heating temperature is preferably 0.5 hours or more and 5 hours or less, more preferably 0.5 hours or more and 3 hours or less, and 1 hour or more and 2 hours or less. Especially preferable.

<< Composition for forming a thermosetting protective film >>
The protective film-forming film can be formed by using a thermosetting protective film-forming composition containing the constituent material. For example, it can be formed by forming a film-like composition for forming a thermosetting protective film and drying it as necessary. For example, a composition for forming a thermosetting protective film is applied to a surface to be formed of a film for forming a thermosetting protective film, and the composition is dried as necessary to form a thermosetting protective film on a target portion. A film can be formed. The ratio of the contents of the components that do not vaporize at room temperature in the composition for forming a thermosetting protective film is usually the same as the ratio of the contents of the components of the film for forming a thermosetting protective film. Here, "normal temperature" is as described above.

The coating of the composition for forming a thermosetting protective film can be performed, for example, in the same manner as in the case of coating the pressure-sensitive adhesive composition described later.

The drying conditions of the composition for forming a thermosetting protective film are not particularly limited, but the composition for forming a thermosetting protective 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 protective film (III-1)>
As the thermosetting protective film forming composition, for example, the thermosetting protective film forming composition (III-1) containing the polymer component (A) and the thermosetting component (B) (in the present specification). May be abbreviated as "composition for forming a protective film (III-1)") and the like.

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting film-forming property, flexibility, etc. to a film for forming a thermosetting protective film. The polymer component (A) has thermoplasticity and does not have thermosetting property.
The polymer component (A) contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds. , Their combinations and ratios can be arbitrarily selected.

Examples of the polymer component (A) include a thermoplastic acrylic resin, a thermoplastic polyester resin (thermoplastic resin having an ester bond), a thermoplastic polyurethane resin (thermoplastic resin having a urethane bond), and a thermoplastic acrylic. Urethane resin, thermoplastic silicone resin (thermoplastic resin with siloxane bond), thermoplastic rubber resin (thermoplastic resin with rubber structure), thermoplastic phenoxy resin, thermoplastic polyimide (thermoplastic resin with imide bond) Etc., and a thermoplastic acrylic resin is preferable.
"In the present specification, the description of" thermoplastic "may be omitted in the names of these resins. For example, the "thermoplastic acrylic resin" may be simply referred to as the "acrylic resin".

The acrylic resin is a resin containing a structural unit derived from a (meth) acrylic acid ester which is a monomer. The term "derived" as used herein means that the monomer has undergone a structural change necessary for polymerization.
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.

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. When the weight average molecular weight of the acrylic resin is at least the above lower limit value, the shape stability (stability with time during storage) of the film for forming a thermosetting protective film is improved. Further, when the weight average molecular weight of the acrylic resin is not more than the above upper limit value, the film for forming a thermosetting protective film easily follows the uneven surface of the adherend, and the adherend and the thermosetting protective film are formed. The generation of voids and the like with the film is further suppressed.

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 glass transition temperature (Tg) of the acrylic resin is preferably -60 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 protective film and the support sheet is suppressed, and the peelability of the support sheet is improved. Further, when the Tg of the acrylic resin is not more than the above upper limit value, the adhesive force between the thermosetting protective film forming film and the protective film to the adherend is improved.

The glass transition temperature (Tg) of the acrylic resin can be obtained from the calculation using the Fox formula shown below.
1 / Tg = (W1 / Tg1) + (W2 / Tg2) + ... + (Wm / Tgm) (In the formula, Tg is the glass transition temperature of the acrylic resin, and Tg1, Tg2, ... Tgm is the acrylic resin. It is the glass transition temperature of the homopolymer of each monomer as a raw material, and W1, W2, ... Wm is the mass fraction of each monomer. However, W1 + W2 + ... + Wm = 1).
For the glass transition temperature of the homopolymer of each monomer in the Fox formula, the values described in the Polymer Data Handbook or the Adhesive Handbook can be used. For example, the Tg of a methyl acrylate homopolymer is 10 ° C, and the Tg of a 2-hydroxyethyl acrylate homopolymer is −15 ° C.

The acrylic resin is selected from, for example, a polymer of one or more (meth) acrylic acid esters; (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylol acrylamide, and the like. Examples thereof include copolymers of two or more types of monomers.

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 ((meth) lauryl acrylate), (meth) tridecyl acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), (meth) acrylate The alkyl groups constituting the alkyl ester, such as pentadecyl, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), (Meta) acrylic acid alkyl ester having a chain structure with 1 to 18 carbon atoms;
(Meta) Acrylic acid cycloalkyl esters such as (meth) acrylate isobornyl, (meth) acrylate 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 acrylic resin is, for example, one or more monomers selected from (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide and the like, in addition to the (meth) acrylic acid ester. May be copolymerized with each other.

The monomer constituting the acrylic resin may be only one type, may be two or more types, and when there are two or more types, 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 composite sheet for forming a protective film tends to be improved.

In the present specification, as the polymer component (A), a thermoplastic resin other than the acrylic resin (hereinafter, may be simply abbreviated as “thermoplastic resin”) may be used in combination with the acrylic resin.
By using the thermoplastic resin, the peelability of the protective film from the support sheet is improved, and the film for forming the thermosetting protective film easily follows the uneven surface of the adherend, so that the adherend and the thermosetting The generation of voids and the like may be further suppressed with the film for forming the sex protective film.

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 resin, polyurethane resin, phenoxy resin, polybutene, polybutadiene, polystyrene and the like.

The thermoplastic resin contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, and when two or more kinds, they are used. The combination and ratio of are arbitrarily selectable.

In the protective film forming composition (III-1), the ratio of the content of the polymer component (A) to the total content of all the components other than the solvent (that is, heat curing in the thermosetting protective film forming film). The ratio of the content of the polymer component (A) to the total mass of the film for forming the sex protective film) is preferably 1% by mass or more and less than 85% by mass regardless of the type of the polymer component (A). It is preferably 2% by mass or more and less than 65% by mass, more preferably 3% by mass or more and less than 50% by mass, further preferably 4% by mass or more and less than 40% by mass, and 5% by mass or more and 35% by mass. It is particularly preferably less than%, and particularly preferably 10% by mass or more and less than 30% by mass.

The polymer component (A) may also correspond to the thermosetting component (B). In the present specification, when the protective film-forming composition (III-1) contains a component corresponding to both the polymer component (A) and the thermosetting component (B), a protective film is formed. The composition for use (III-1) is considered to contain a polymer component (A) and a thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) is a component that has thermosetting property and cures a thermosetting protective film forming film to form a hard protective film.
The thermosetting component (B) contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds. If so, their combinations and ratios can be arbitrarily selected.

Examples of the thermosetting component (B) include an epoxy-based thermosetting resin (thermosetting resin having an epoxy group), a thermosetting polyimide (thermosetting resin having an imide bond), and a thermosetting polyurethane-based resin. (Thermosetting resin having urethane bond), Thermosetting unsaturated polyester resin (thermosetting resin having ester bond and unsaturated bond between carbon atoms), thermosetting silicone resin (siloxane bond) Thermosetting resin) and the like, and an epoxy-based thermosetting resin is 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 protective film-forming composition (III-1) and the thermosetting film-forming film may be only one kind, two or more kinds, or two or more kinds. , Their combinations and ratios can be arbitrarily selected.

・ Epoxy resin (B1)
The epoxy resin (B1) may have an epoxy group in the molecule and may be known. For example, a polyfunctional epoxy resin, a biphenyl compound, a bisphenol A diglycidyl ether and a hydrogenated product thereof. Bifunctional or more having two or more epoxy groups in the molecule, such as orthocresol novolak epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, etc. 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 composite sheet for forming a protective film 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 (vinyl group), a 2-propenyl group (allyl group), a (meth) acryloyl group, and a (meth) group. Examples thereof include an acrylamide group, and an acryloyl group is preferable.
In addition, in this specification, a "derivative" means a compound in which one or more hydrogen atoms of the original compound are substituted with a group (substituent) other than the hydrogen atom.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but may be 300 to 30,000 from the viewpoint of the curability of the thermosetting protective film forming film and the strength and heat resistance of the protective film after curing. It is preferably 300 to 10000, more preferably 300 to 3000, and particularly preferably 300 to 3000.
The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1100 g / eq, more preferably 150 to 1000 g / eq.

As the epoxy resin (B1), one type may be used alone, two or more types may be used in combination, and when two or more types are used in combination, the combination and ratio thereof can be arbitrarily selected.

・ 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 phenolic resin, biphenol, novolak type phenolic resin, dicyclopentadien phenolic resin, and aralkylphenolic resin.
Among the thermosetting agents (B2), examples of the amine-based curing agent having an amino group include dicyandiamide (hereinafter, 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) preferably has a high softening point or glass transition temperature from the viewpoint of improving the peelability of the protective film from the support sheet. ..

The thermosetting agent (B2) is solid at room temperature and does not show curing activity with respect to the epoxy resin (B1), while it melts by heating and shows curing activity with respect to the epoxy resin (B1). It is preferably a curing agent (hereinafter, may be abbreviated as "thermosetting latent epoxy resin curing agent").
The thermosetting latent epoxy resin curing agent is stably dispersed in the epoxy resin (B1) in the film for forming a thermosetting protective film at room temperature, but is compatible with the epoxy resin (B1) by heating. , Reacts with epoxy resin (B1). By using the thermally active latent epoxy resin curing agent, the storage stability of the composite sheet for forming a protective film is remarkably improved. For example, the movement of this curing agent from the protective film-forming film to the adjacent support sheet is suppressed, and the decrease in thermosetting property of the thermosetting protective film-forming film is effectively suppressed. Then, since the thermosetting property of the film for forming the thermosetting protective film by heating becomes higher, the pick-up property of the chip with the protective film described later is further improved.

Examples of the thermally active latent epoxy resin curing agent include onium salts, dibasic acid hydrazides, dicyandiamides, amine adducts of curing agents, and the like.

Among the thermosetting agents (B2), the number average molecular weight of resin components such as polyfunctional phenol resin, novolak type phenol resin, dicyclopentadiene phenol resin, and aralkyl phenol resin is preferably 300 to 30,000. It is more preferably 400 to 10000, and particularly preferably 500 to 3000.
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.

As the thermosetting agent (B2), one type may be used alone, two or more types may be used in combination, and when two or more types are used in combination, the combination and ratio thereof can be arbitrarily selected.

In the protective film-forming composition (III-1) and the thermosetting protective film-forming film, the content of the thermosetting agent (B2) is 0, based on 100 parts by mass of the content of the epoxy resin (B1). It is preferably 1 to 500 parts by mass, and more preferably 1 to 200 parts by mass. When the content of the thermosetting agent (B2) is at least the lower limit value, the curing of the thermosetting protective film forming film becomes easier to proceed. Further, when the content of the thermosetting agent (B2) was not more than the upper limit value, the hygroscopicity of the thermosetting protective film forming film was reduced, and it was obtained by using the protective film forming composite sheet. The reliability of the package is improved.

In the protective film forming composition (III-1) and the thermosetting protective film forming film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)). The amount) is preferably 1 to 200 parts by mass, more preferably 5 to 150 parts by mass, and 10 to 100 parts by mass with respect to 100 parts by mass of the content of the polymer component (A). Is particularly preferable. When the content of the thermosetting component (B) is in such a range, the adhesive force between the protective film and the support sheet is suppressed, and the peelability of the support sheet is improved.

The thermosetting protective film forming film of the embodiment contains a polymer component (A) and a thermosetting component (B), and the polymer component (A) is an acrylic resin and is a thermosetting component. An example of (B) is an epoxy-based thermosetting resin composed of an epoxy resin (B1) and a thermosetting agent (B2).

[Curing accelerator (C)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the protective film forming composition (III-1).
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 protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds. , Their combinations and ratios can be arbitrarily selected.

When the curing accelerator (C) is used, the content of the curing accelerator (C) in the protective film forming composition (III-1) and the thermosetting protective film forming film is the thermosetting component (B). The content is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass with respect to 100 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 contained in the film for forming a thermosetting protective film under high temperature and high humidity conditions. The effect of suppressing segregation by moving to the adhesion interface side with the adherend is enhanced, and the reliability of the package obtained by using the composite sheet for forming a protective film is further improved.

[Filler (D)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a filler (D). Since the thermosetting protective film forming film contains the filler (D), the protective film obtained by curing the thermosetting protective film forming film can easily adjust the thermal expansion coefficient, and this heat By optimizing the expansion coefficient for the object to be formed of the protective film, the reliability of the package obtained by using the composite sheet for forming the protective film is further improved. Further, when the thermosetting protective film forming film contains the filler (D), the hygroscopicity of the 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 protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, may be two or more kinds, and when there are two or more kinds, The combination and ratio thereof can be arbitrarily selected.

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 protective film forming composition (III-1) (that is, thermosetting protection). The ratio of the content of the filler (D) to the total mass of the thermosetting protective film forming film in the film forming film) is preferably more than 5% by mass and less than 85% by mass, preferably 20% by mass. It is more than% and less than 85% by mass, more preferably more than 30% by mass and less than 80% by mass, still more preferably more than 45% by mass and less than 80% by mass, and 46% by mass. It is particularly preferable that it is larger than% and less than 75% by mass. When the content of the filler (D) is in such a range, the above-mentioned coefficient of thermal expansion can be more easily adjusted.

[Coupling agent (E)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming 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, it is possible to improve the adhesiveness and adhesion of the thermosetting protective film forming film to the adherend. it can. Further, by using the coupling agent (E), the protective film obtained by curing the film for forming a thermosetting protective 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 protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds. , Their combinations and ratios can be arbitrarily selected.

When the coupling agent (E) is used, the content of the coupling agent (E) in the protective film forming composition (III-1) and the thermosetting protective film forming film is the polymer component (A) and The total content of the thermosetting component (B) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and 0.1 to 5 parts by mass with respect to 100 parts by mass. It is particularly preferable that it is by mass. When the content of the coupling agent (E) is equal to or higher than the lower limit value, the dispersibility of the filler (D) in the resin is improved and the thermosetting protective film forming film is adhered to the adherend. The effect of using the coupling agent (E), such as improvement of the property, can be obtained more remarkably. 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), one having a functional group such as a vinyl group capable of binding to another compound such as the above-mentioned acrylic resin, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group and an isocyanate group. When used, the protective film-forming composition (III-1) and the thermosetting protective film-forming film contain a cross-linking agent (F) for binding the functional group to another compound and cross-linking. May be good. By cross-linking with the cross-linking agent (F), the storage elastic modulus E'of the above-mentioned thermosetting protective film forming film can be easily adjusted to a suitable range.

Such a structure includes a polymer component (A) having a structural unit containing a functional group (a1) and a cross-linking agent (F) having two or more functional groups (f1) that react with the functional group (a1). An example of a film for forming a thermosetting protective film can be exemplified.

The content of the structural unit containing the functional group (a1) is preferably 3 parts by mass or more, and is preferably 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the polymer component (A). Is more preferable, and it is more preferably 5 parts by mass or more and 30 parts by mass or less, and particularly preferably 7 parts by mass or more and 20 parts by mass or less. When the content of the structural unit containing the functional group (a1) is within the above range, the storage elastic modulus E'of the above-mentioned film for forming a thermosetting protective film can be easily adjusted to a suitable range. is there.

Further, the content of the functional group (f1) is preferably 0.005 to 4 equivalents, more preferably 0.05 to 2 equivalents, relative to 1 equivalent of the functional group (a1). It is more preferably 0.1 to 1 equivalent. When the content of the functional group (f1) is within the above range, the storage elastic modulus E'of the above-mentioned thermosetting protective film forming film can be easily adjusted to a suitable range.

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" is a low content of the aromatic polyhydric isocyanate compound, the aliphatic polyvalent isocyanate compound or the alicyclic polyvalent isocyanate compound, and ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil and the like. It means a reaction product with a molecularly active hydrogen-containing compound, and examples thereof include a xylylene diisocyanate adduct of trimethylol propane as described later. Further, the "terminal isocyanate urethane prepolymer" is as described above.

Examples of the organic polyisocyanate compound include toluene diisocyanate (TDI) -based, hexamethylene diisocyanate (HDI) -based, xylylene diisocyanate (XDI) -based, and isocyanate-based cross-linking agents such as adducts of these diisocyanates (that is, isocyanate groups). A cross-linking agent having two or more).

More specifically, as the organic polyvalent isocyanate compound, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane- 4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; tri Compounds in which any one or more of tolylene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate are added to all or some hydroxyl groups of a polyol such as methylolpropane; lysine diisocyanate and the like can be mentioned. The number of isocyanate groups per molecule of the organic multivalent isocyanate compound is preferably 2 to 3.

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) results in a film for forming a thermosetting protective film. The crosslinked structure can be easily introduced.

As such a configuration, a thermosetting protective film forming film in which the functional group (f1) is an isocyanate group and the functional group (a1) is a hydroxyl group can be exemplified. Examples of the cross-linking agent (F) having two or more isocyanate groups in the molecule include isocyanate-based cross-linking agents, and the above-mentioned organic polyvalent isocyanate compounds can be exemplified. Aromatic polyvalent isocyanate compounds such as XDI-based and TDI-based. Is preferable from the viewpoint of stability when used as a protective film-forming composition and reactivity when used as a protective film-forming film. The structural unit containing a hydroxyl group is derived from a hydroxyl group-containing monomer having a hydroxyl group in the molecule, and as the hydroxyl group-containing monomer, the hydroxyl group-containing (meth) acrylic acid ester in the above polymer component (A) can be exemplified (meth). ) Hydroxyalkyl acrylate is preferred.

The cross-linking agent (F) contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds, when there are two or more kinds. 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 protective film-forming composition (III-1) is 0, based on 100 parts by mass of the content of the polymer component (A). It is preferably 01 to 20 parts by mass, more 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, the adhesive force of the thermosetting protective film forming film with the support sheet and the wafer or chip of the thermosetting protective film forming film are obtained. It is suppressed that the adhesive force with and is excessively lowered.

[Energy ray curable resin (G)]
The protective film-forming composition (III-1) may contain an energy ray-curable resin (G). Since the thermosetting protective film forming film contains the energy ray curable resin (G), its characteristics can be changed by irradiation with energy rays.

The energy ray-curable resin (G) is obtained by polymerizing (curing) an energy ray-curable compound.
Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate-based compounds having a (meth) acryloyl group are preferable.

Examples of the acrylate-based compound include trimethyl propantri (meth) acrylate, tetramethylol methanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol monohydroxypenta ( Chain aliphatic skeleton-containing (meth) acrylates such as meta) acrylates, dipentaerythritol hexa (meth) acrylates, 1,4-butylene glycol di (meth) acrylates, and 1,6-hexanediol di (meth) acrylates; Cyclic aliphatic skeleton-containing (meth) acrylate such as cyclopentanyldi (meth) acrylate; Polyalkylene glycol (meth) acrylate such as polyethylene glycol di (meth) acrylate; Oligoester (meth) acrylate; Urethane (meth) acrylate oligomer ; Epoxy-modified (meth) acrylate; polyether (meth) acrylate other than the polyalkylene glycol (meth) acrylate; itaconic acid oligomer and the like.

The weight average molecular weight of the energy ray-curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

The energy ray-curable compound used for the polymerization may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

The energy ray-curable resin (G) contained in the protective film forming composition (III-1) may be only one type, two or more types, and when two or more types, the combination and ratio thereof are It can be selected arbitrarily.

In the protective film forming composition (III-1), the ratio of the content of the energy ray-curable resin (G) to the total mass of the protective film forming composition (III-1) is 1 to 95% by mass. It is preferably 2 to 90% by mass, and particularly preferably 3 to 85% by mass.

[Photopolymerization Initiator (H)]
When the protective film-forming composition (III-1) contains the energy ray-curable resin (G), the photopolymerization initiator (H) is used to efficiently proceed with the polymerization reaction of the energy ray-curable resin (G). ) May be contained.

Examples of the photopolymerization initiator (H) in the protective film forming composition (III-1) include the same photopolymerization initiator (H) as in the pressure-sensitive adhesive composition (I-1).

The photopolymerization initiator (H) contained in the protective film forming composition (III-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof are arbitrary. Can be selected.

In the protective film forming composition (III-1), the content of the photopolymerization initiator (H) is 0.1 to 20 parts by mass with respect to 100 parts by mass of the energy ray curable resin (G). It is preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass.

[Colorant (I)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a colorant (I).
Examples of the colorant (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

Examples of the organic pigments and organic dyes include aminium pigments, cyanine pigments, merocyanine pigments, croconium pigments, squalium pigments, azulenium pigments, polymethine pigments, naphthoquinone pigments, pyrylium pigments, and phthalocyanines. Colors, naphthalocyanine pigments, naphtholactam pigments, azo pigments, condensed azo pigments, indigo pigments, perinone pigments, perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, quinophthalone pigments , Pyrrole pigments, thioindigo pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indolphenol pigments, triallylmethane pigments, anthraquinone pigments, dioxazine pigments, naphthol pigments, azomethine pigments. Examples thereof include dyes, benzimidazolone dyes, pyranthron dyes and slene colors.

Examples of the inorganic pigment include carbon black, cobalt pigment, iron pigment, chromium pigment, titanium pigment, vanadium pigment, zirconium pigment, molybdenum pigment, ruthenium pigment, platinum pigment, and ITO ( Examples thereof include indium tin oxide) dyes and ATO (antimons tin oxide) dyes.

The colorant (I) contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds, when there are two or more kinds. The combination and ratio thereof can be arbitrarily selected.

When the colorant (I) is used, the content of the colorant (I) in the thermosetting protective film forming film may be appropriately adjusted according to the intended purpose. For example, the protective film may be printed by laser irradiation, and by adjusting the content of the colorant (I) of the thermosetting protective film forming film and adjusting the light transmittance of the protective film, the protective film may be printed. The print visibility can be adjusted. Further, by adjusting the content of the colorant (I) of the thermosetting protective film forming film, the design of the protective film can be improved and the grinding marks on the back surface of the wafer can be made difficult to see. In consideration of this point, in the protective film forming composition (III-1), the ratio of the content of the colorant (I) to the total content of all the components other than the solvent (that is, the formation of a thermocurable protective film). The ratio of the content of the colorant (I) to the total mass of the film for forming the heat-curable protective film in the film for use) is preferably 0.1 to 10% by mass, preferably 0.1 to 7.5% by mass. It is more preferably 0.1 to 5% by mass, and particularly preferably 0.1 to 5% by mass. When the content of the colorant (I) is at least the lower limit, the effect of using the colorant (I) is more remarkable. Further, when the content of the colorant (I) is not more than the upper limit value, an excessive decrease in the light transmittance of the thermosetting protective film forming film is suppressed.

[General-purpose additive (J)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a general-purpose additive (J) as long as the effects of the present invention are not impaired.
The general-purpose additive (J) may be a known one and may be arbitrarily selected depending on the intended purpose, and is not particularly limited, but preferred ones are, for example, plasticizers, antistatic agents, antioxidants, gettering agents and the like. Can be mentioned.

The general-purpose additive (I) contained in the protective film forming composition (III-1) and the thermosetting protective film forming film may be only one kind, two or more kinds, or two or more kinds. , Their combinations and ratios can be arbitrarily selected.
The contents of the protective film-forming composition (III-1) and the general-purpose additive (I) of the thermosetting protective film-forming film are not particularly limited and may be appropriately selected depending on the intended purpose.

[solvent]
The protective film-forming composition (III-1) preferably further contains a solvent. The protective film-forming composition (III-1) containing a solvent has good handleability.
The solvent is not particularly limited, but preferred ones are, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol) and 1-butanol. Examples include esters such as ethyl acetate and butyl 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).
The solvent contained in the protective film forming composition (III-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

The solvent contained in the protective film-forming composition (III-1) is preferably methyl ethyl ketone or the like from the viewpoint that the components contained in the protective film-forming composition (III-1) can be mixed more uniformly.

<< Method for producing a composition for forming a thermosetting protective film >>
A thermosetting protective film-forming composition such as the protective film-forming composition (III-1) 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 adding and mixing each component may be appropriately adjusted in consideration of the conditions under which each compounding component is unlikely to deteriorate, but the temperature is preferably 15 to 30 ° C.

<< Manufacturing method of film for forming thermosetting protective film >>
The thermosetting protective film forming film can be produced by applying a thermosetting protective film forming composition on a release film (preferably a peeling-treated surface thereof) and drying it if necessary. The manufacturing method at this time is as described above.
As shown in FIG. 1, for example, the thermosetting protective film forming film is usually stored in a state where release films are attached to both sides thereof. For that purpose, the exposed surface of the protective film forming film formed on the release film as described above (the surface opposite to the side on which the release film is provided) is further covered with the release film (preferably the release-treated surface thereof). Should be pasted together.

◇ How to use the protective film forming film By providing the protective film forming film on the support sheet as described above, the protective film forming composite sheet can be formed. The protective film-forming composite sheet can be attached to the back surface of the wafer or chip (the surface opposite to the electrode-forming surface) via the protective film-forming film. Hereinafter, from this state, the target chip with a protective film can be manufactured by the manufacturing method described later, and further, an apparatus (for example, a semiconductor apparatus) can be manufactured.

On the other hand, the protective film forming film may be provided first on the back surface of the wafer instead of the support sheet. For example, first, a protective film forming film is attached to the back surface of the wafer or chip, and then a support sheet is attached to the exposed surface (the surface opposite to the side attached to the wafer or chip) of the protective film forming film. Can be matched. When the protective film forming film has energy ray curability as well as thermosetting property, the protective film forming film in the attached state is irradiated with energy rays to be cured, and then the protective film forming film is formed. A support sheet may be attached to the exposed surface (the surface opposite to the side attached to the wafer) to form a composite sheet for forming a protective film. Hereinafter, from this state, a target chip with a protective film can be manufactured by a manufacturing method described later, and further, an apparatus (for example, a semiconductor apparatus) can be manufactured.

Protective Film Forming Composite Sheet The protective film forming composite sheet according to the embodiment of the present invention includes the support sheet of the embodiment and the thermosetting protective film forming film of the embodiment.
The film for forming a thermosetting protective film is provided on the support sheet.
The composite sheet for forming a protective film according to an embodiment of the present invention is also simply referred to as "composite sheet for forming a protective film".

In the present specification, the laminated structure of the support sheet and the cured product of the thermosetting protective film forming film (in other words, the support sheet and the protective film) even after the thermosetting protective film forming film is cured. This laminated structure is referred to as a "composite sheet for forming a protective film" as long as the above is maintained.

The thickness of the wafer or chip on which the composite sheet for forming the protective film may be used is not particularly limited, but is preferably 30 to 1000 μm in that it can be more easily divided into chips, which will be described later. More preferably, it is ~ 400 μm.

◎ Support sheet The support sheet may be composed of one layer (single layer) or may be composed of two or more layers. When the support sheet is composed of 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 as long as the effects of the present invention are not impaired.

As a preferable support sheet, for example, a base material is provided, and the pressure-sensitive adhesive layer is directly contacted and laminated on the base material (in other words, the base material and the pressure-sensitive adhesive layer are directly contacted and laminated in this order. (Things); The base material, the intermediate layer, and the pressure-sensitive adhesive layer are laminated in this order in direct contact with each other in the thickness direction thereof; the base material alone is used.

FIG. 2 is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film according to the present invention.
The protective film-forming composite sheet 1 shown here includes a base material 11, an adhesive layer 12, and a thermosetting protective film-forming film 13 in this order. Further, the protective film forming composite sheet 1 further includes a release film 15 on the thermosetting protective film forming film 13, and the release film 15 is removed when the protective film forming composite sheet 1 is used. The thermosetting protective film forming film 13 becomes a protective film by being thermosetting.

In the protective film forming composite sheet 1, the pressure-sensitive adhesive layer 12 is laminated on the surface 11a of the base material 11, and the thermosetting protective film forming film 13 is laminated on a part of the surface 12a of the pressure-sensitive adhesive layer 12. There is. Then, on the exposed surface of the surface 12a of the pressure-sensitive adhesive layer 12 on which the thermosetting protective film forming film 13 is not laminated, and on the surface 13a (upper surface and side surface) of the thermosetting protective film forming film 13. , The release film 15 is laminated.

The composite sheet for forming a protective film is subjected to laser light from the side of the support sheet with respect to the film for forming a heat-curable protective film or the protective film after the film for forming a heat-curable protective film is heat-cured. It is preferable that the support sheet has transparency to the laser beam for laser printing so that the laser beam can pass through the support sheet to perform laser printing.

Further, in the process of manufacturing a chip with a protective film, the wafer is irradiated with an infrared laser beam from the support sheet side (for example, stealth dicing (SD)), and the infrared laser beam is transmitted through the support sheet. It is preferable that the support sheet has transparency to the laser light in the infrared region so that the modified layer can be formed inside the wafer.

Further, by cool-expanding (CE) the composite sheet for forming a protective film with the wafer, the wafer can be divided and individualized starting from the formation site of the modified layer of the wafer. At this time, whether or not the thermosetting protective film forming film or the protective film was surely cut, whether or not the chip was chipped, and whether the laser beam used for infrared inspection passed through the support sheet to facilitate the state of the chip. Can be inspected. It is preferable that the support sheet has transparency to laser light during infrared inspection and the film for forming a thermosetting protective film is colored so as to suppress a decrease in manufacturing efficiency of the semiconductor device. .. As a result, it is possible to easily inspect whether or not the thermosetting protective film forming film has been reliably cut, and it is possible to suppress a decrease in the manufacturing efficiency of the chip with the protective film or the semiconductor device.

FIG. 3 is a cross-sectional view schematically showing another example of the composite sheet for forming a protective film. In FIG. 3, the same elements as those shown in FIG. 2 are designated by the same reference numerals as those in FIG. 2, and detailed description thereof will be omitted. This also applies to the figures after FIG.
The protective film-forming composite sheet 2 shown here is the protective film-forming composite sheet 1 shown in FIG. 2, except that the adhesive layer 16 for jigs is laminated on a part of the surface 12a of the pressure-sensitive adhesive layer 12. Is the same as. The jig adhesive layer 16 may be laminated on the surface of the protective film forming film 23, but both of them are provided by the jig adhesive layer 16 being laminated on the surface 12a of the adhesive layer 12. The sticky layers are bonded to each other, and the adhesion between the layers is improved. Further, when the table is pushed up by the expansion in the "dividing step" described later, since the protective film forming film does not exist in the extra portion directly above the table, the protective film forming film is unlikely to float or peel off.

In the protective film forming composite sheet 2 shown in FIG. 3, the back surface of the semiconductor wafer (not shown) is attached to the front surface 23a of the thermosetting protective film forming film 23 in a state where the release film 15 is removed, and further. The upper surface of the surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame and used.

The composite sheet for forming a protective film is not limited to the one shown in FIGS. 2 to 3, and a part of the composite sheet shown in FIGS. 2 to 3 has been changed or deleted within a range not impairing the effect of the present invention. , Other configurations may be added to those described so far.

The composite sheet for forming a protective film is a laminate provided with a support sheet, a film for forming a thermosetting protective film, and a wafer or chip in this order, which is attached to the wafer or chip in the method for manufacturing a chip with a protective film described later. It can be used when preparing.
Hereinafter, each configuration of the protective film forming composite sheet will be described in detail.

○ Base material The base material is in the form of a sheet or a film, and examples of the constituent material thereof include various resins.
Examples of the resin include polyethylenes such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE); other than polyethylenes such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin. Polyethylene; ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-norbornene copolymer (ie, monomer) Polymers obtained using ethylene as a polymer); vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymers (ie, resins obtained using vinyl chloride as a monomer); polystyrene; polycycloolefins; Polypolymers such as polyethylene terephthalates, polyethylene naphthalates, polybutylene terephthalates, polyethylene isophthalates, polyethylene-2,6-naphthalenedicarboxylates, all aromatic polyesters in which all constituent units have aromatic cyclic groups; two or more Examples thereof include the polymer of the polyester; poly (meth) acrylic acid ester; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene oxide; polyphenylene sulfide; polysulfone; polyether ketone 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.
Further, as the resin, 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 base material may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

The base material may be composed of one layer (single layer), may be composed of two or more layers, and when composed of a plurality of layers, the plurality of layers may be the same or different from each other. The combination of layers is not particularly limited.

The thickness of the base material is preferably 50 to 300 μm, more preferably 60 to 100 μm. When the thickness of the base material is within such a range, the flexibility of the composite sheet for forming the protective film and the adhesiveness to the wafer or the chip are further improved.
Here, the "thickness of the base material" means the thickness of the entire base material, and for example, the thickness of the base material composed of a plurality of layers means the total thickness of all the layers constituting the base material. means.

The base material preferably contains polypropylene because it has excellent heat resistance and has appropriate flexibility, so that it has cool expandability and also has good pickup suitability.
The polypropylene-containing base material may be, for example, a single-layer or multi-layer base material made of only polypropylene, or a multi-layer base material in which a polypropylene layer and a resin layer other than polypropylene are laminated. You may.
Since the base material of the protective film-forming film has heat resistance, it is possible to effectively prevent the support sheet from bending even under the condition that the thermosetting protective film-forming film is heat-cured.

It is preferable that the base material has a high accuracy of thickness, that is, a base 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 base material having such a high accuracy of thickness, for example, polyethylene, polyolefin other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymer and the like are used. Can be mentioned.

In addition to the main constituent materials such as the resin, the base material contains various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers). You may.

It is preferable that the optical characteristics of the base material satisfy the optical characteristics of the support sheet described above. For example, the base material may be transparent, opaque, colored depending on the purpose, or another layer may be vapor-deposited.

In order to improve the adhesion of the base material to other layers such as the pressure-sensitive adhesive layer provided on the base material, the base material is subjected to unevenness treatment by sandblasting treatment, solvent treatment, etc., corona discharge treatment, electron beam irradiation treatment, plasma treatment. , Ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment and other oxidation treatments may be applied to the surface.
Further, the base material may have a surface surface treated with a primer.
In addition, the base material prevents the base material from adhering to other sheets and the base material from adhering to the adsorption table when the antistatic coat layer; the composite sheet for forming the protective film is laminated and stored. It may have a layer or the like.

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

○ Adhesive layer The adhesive layer is in the form of a sheet or a film and contains an adhesive.
Examples of the pressure-sensitive adhesive include adhesive resins such as acrylic resin, urethane-based resin, rubber-based resin, silicone-based resin, epoxy-based resin, polyvinyl ether, polycarbonate, and ester-based resin, and acrylic-based resin is preferable. ..

In the present specification, the "adhesive resin" is a concept including both a resin having adhesiveness and a resin having adhesiveness, and for example, not only the resin itself having adhesiveness but also the resin itself has adhesiveness. Also included are resins that exhibit adhesiveness when used in combination with other components such as additives, and resins that exhibit adhesiveness due to the presence of a trigger such as heat or water.

The pressure-sensitive adhesive layer may be composed of one layer (single layer), may be composed of two or more layers, and when composed of a plurality of layers, the plurality of layers may be the same or different from each other. The combination of multiple layers is not particularly limited.

The thickness of the pressure-sensitive adhesive layer is preferably 1 to 100 μm, more preferably 1 to 60 μm, and particularly preferably 1 to 30 μm.
Here, the "thickness of the pressure-sensitive adhesive layer" means the thickness of the entire pressure-sensitive adhesive layer, and for example, the thickness of the pressure-sensitive adhesive layer composed of a plurality of layers is the sum of all the layers constituting the pressure-sensitive adhesive layer. Means the thickness of.

The optical properties of the pressure-sensitive adhesive layer preferably satisfy the optical properties of the support sheet described above. That is, the pressure-sensitive adhesive layer may be transparent, opaque, or colored depending on the purpose.

The pressure-sensitive adhesive layer may be formed by using an energy ray-curable pressure-sensitive adhesive or may be formed by using a non-energy ray-curable pressure-sensitive adhesive. The pressure-sensitive adhesive layer formed by using the energy ray-curable pressure-sensitive adhesive can easily adjust the physical properties before and after curing.

In the present specification, the "energy beam" means an electromagnetic wave or a charged particle beam having an energy quantum, and examples thereof include ultraviolet rays, radiation, and electron beams.
Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, an LED lamp, or the like as an ultraviolet source. The electron beam can be irradiated with an electron beam generated by an electron beam accelerator or the like.
In the present specification, "energy ray curable" means the property of being cured by irradiating with energy rays, and "non-energy ray curable" means the property of not being cured by irradiating with energy rays. To do.

<< Adhesive composition >>
The pressure-sensitive adhesive layer can be formed by using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. For example, it can be formed by forming a film of the pressure-sensitive adhesive composition into a sheet or a film and drying it as needed. For example, the pressure-sensitive adhesive layer can be formed on a target portion by applying the pressure-sensitive adhesive composition to the surface to be formed of the pressure-sensitive adhesive layer and drying it if necessary. A more specific method for forming the pressure-sensitive adhesive layer will be described in detail later together with a method for forming the other layers. The ratio of the contents of the components that do not vaporize at room temperature in the pressure-sensitive adhesive composition is usually the same as the ratio of the contents of the components in the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive composition may be applied 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 coater. , A method using various coaters such as a Meyer bar coater and a kiss coater.

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

When the pressure-sensitive adhesive layer is energy ray-curable, the pressure-sensitive adhesive composition containing the energy ray-curable pressure-sensitive adhesive, that is, the energy ray-curable pressure-sensitive adhesive composition, for example, is a non-energy ray-curable pressure-sensitive adhesive. Adhesive composition (I-1) containing a resin (I-1a) (hereinafter, may be abbreviated as "adhesive resin (I-1a)") and an energy ray-curable compound; non-energy An energy ray-curable adhesive resin (I-2a) in which an unsaturated group is introduced into the side chain of the linear curable adhesive resin (I-1a) (hereinafter referred to as "adhesive resin (I-2a)"). A pressure-sensitive adhesive composition (I-2) containing (may be abbreviated); a pressure-sensitive adhesive composition (I-3) containing the pressure-sensitive resin (I-2a) and an energy ray-curable compound, etc. Can be mentioned.

<Adhesive composition (I-1)>
As described above, the pressure-sensitive adhesive composition (I-1) contains a non-energy ray-curable pressure-sensitive adhesive resin (I-1a) and an energy ray-curable compound.

[Adhesive resin (I-1a)]
The adhesive resin (I-1a) is preferably an acrylic resin.
Examples of the acrylic resin include acrylic polymers having at least a structural unit derived from (meth) acrylic acid alkyl ester.
The structural unit of the acrylic resin may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

Examples of the (meth) acrylic acid alkyl ester include those in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms, and the alkyl group is linear or branched. Is preferable.
More specifically, as the (meth) acrylic acid alkyl ester, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, (meth) acrylic acid. n-butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-Ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) ) Undecyl acrylate, dodecyl (meth) acrylate (lauryl acrylate (meth), tridecyl (meth) acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, ( Hexadecyl acrylate ((meth) palmityl acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), nonadecil (meth) acrylate, icosyl (meth) acrylate, etc. Can be mentioned.

From the viewpoint of improving the adhesive strength of the pressure-sensitive adhesive layer, the acrylic polymer preferably has a structural unit derived from a (meth) acrylic acid alkyl ester having 4 or more carbon atoms in the alkyl group. The alkyl group preferably has 4 to 12 carbon atoms, and more preferably 4 to 8 carbon atoms, from the viewpoint of further improving the adhesive strength of the pressure-sensitive adhesive layer. Further, the (meth) acrylic acid alkyl ester having 4 or more carbon atoms in the alkyl group is preferably a methacrylic acid alkyl ester.

The acrylic polymer preferably has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth) acrylic acid alkyl ester.
As the functional group-containing monomer, for example, the functional group may be a starting point of cross-linking by reacting with a cross-linking agent described later, or the functional group may react with an unsaturated group in an unsaturated group-containing compound described later. Then, there is one that enables the introduction of an unsaturated group into the side chain of the acrylic polymer.

Examples of the functional group in the functional group-containing monomer include a hydroxyl group, a carboxy group, an amino group, an epoxy group and the like.
That is, examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, and an epoxy group-containing monomer.

Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth). (Meta) hydroxyalkyl acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; non- (meth) acrylics such as vinyl alcohol and allyl alcohol. Saturated alcohol (that is, unsaturated alcohol having no (meth) acrylic skeleton) and the like can be mentioned.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid (that is, monocarboxylic acids having ethylenically unsaturated bonds); fumaric acid, itaconic acid, and maleic acid. , Citraconic acid and other ethylenically unsaturated dicarboxylic acids (ie, dicarboxylic acids with ethylenically unsaturated bonds); the anhydrides of the ethylenically unsaturated dicarboxylic acids; carboxyalkyl (meth) acrylates such as 2-carboxyethyl methacrylate. Examples include esters.

As the functional group-containing monomer, a hydroxyl group-containing monomer and a carboxy group-containing monomer are preferable, and a hydroxyl group-containing monomer is more preferable.

The functional group-containing monomer constituting the acrylic polymer may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

In the acrylic polymer, the content of the structural unit derived from the functional group-containing monomer is preferably 1 to 35% by mass, more preferably 2 to 32% by mass, based on the total amount of the structural units. It is particularly preferably 3 to 30% by mass.

The acrylic polymer may further have a structural unit derived from another monomer in addition to the structural unit derived from the (meth) acrylic acid alkyl ester and the structural unit derived from the functional group-containing monomer.
The other monomer is not particularly limited as long as it can be copolymerized with a (meth) acrylic acid alkyl ester or the like.
Examples of the other monomer include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide and the like.

The other monomer constituting the acrylic polymer may be only one kind, may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

The acrylic polymer can be used as the above-mentioned non-energy ray-curable adhesive resin (I-1a).
On the other hand, a product obtained by reacting a functional group in the acrylic polymer with an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group (energy ray-polymerizable group) has the above-mentioned energy ray-curable adhesiveness. It can be used as a resin (I-2a).

The pressure-sensitive adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. You can choose.

In the pressure-sensitive adhesive composition (I-1), the ratio of the content of the pressure-sensitive adhesive resin (I-1a) to the total mass of the pressure-sensitive adhesive composition (I-1) is preferably 5 to 99% by mass. , 10-95% by mass is more preferable, and 15-90% by mass is particularly preferable.

[Energy ray curable compound]
Examples of the energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-1) include monomers or oligomers having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays.
Among the energy ray-curable compounds, examples of the monomer include trimethylpropantri (meth) acrylate, pentaerythritol (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4. Polyvalent (meth) acrylates such as −butylene glycol di (meth) acrylate, 1,6-hexanediol (meth) acrylate; urethane (meth) acrylate; polyester (meth) acrylate; polyether (meth) acrylate; epoxy ( Meta) acrylate and the like can be mentioned.
Among the energy ray-curable compounds, examples of the oligomer include an oligomer obtained by polymerizing the monomers exemplified above.
The energy ray-curable compound has a relatively large molecular weight, and urethane (meth) acrylate and urethane (meth) acrylate oligomer are preferable in that the storage elastic modulus of the pressure-sensitive adhesive layer is not easily lowered.

The energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected. ..

In the pressure-sensitive adhesive composition (I-1), the ratio of the content of the energy ray-curable compound to the total mass of the pressure-sensitive adhesive composition (I-1) is preferably 1 to 95% by mass. It is more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass.

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth) acrylic acid alkyl ester is used as the adhesive resin (I-1a), the pressure-sensitive adhesive composition ( I-1) preferably further contains a cross-linking agent.

The cross-linking agent, for example, reacts with the functional group to cross-link the adhesive resins (I-1a) with each other.
Examples of the cross-linking agent include isocyanate-based cross-linking agents such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates (that is, cross-linking agents having an isocyanate group); epoxy-based cross-linking such as ethylene glycol glycidyl ether. Agent (ie, cross-linking agent having a glycidyl group); Isocyanate-based cross-linking agent such as hexa [1- (2-methyl) -aziridinyl] triphosphatriazine (ie, cross-linking agent having an aziridinyl group); Metal such as aluminum chelate Examples thereof include a chelate-based cross-linking agent (that is, a cross-linking agent having a metal chelate structure); an isocyanurate-based cross-linking agent (that is, a cross-linking agent having an isocyanurate skeleton).
The cross-linking agent is preferably an isocyanate-based cross-linking agent from the viewpoints of improving the cohesive force of the pressure-sensitive adhesive to improve the adhesive force of the pressure-sensitive adhesive layer and being easily available.

The cross-linking agent contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

When a cross-linking agent is used, the content of the cross-linking agent in the pressure-sensitive adhesive composition (I-1) is 0.01 to 50 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-1a). It is preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass.

[Photopolymerization initiator]
The pressure-sensitive adhesive composition (I-1) may further contain a photopolymerization initiator. The pressure-sensitive adhesive composition (I-1) containing a photopolymerization initiator sufficiently undergoes a curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, and benzoin dimethyl ketal; acetophenone, 2-hydroxy. Acetphenone compounds such as -2-methyl-1-phenyl-propane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one; bis (2,4,6-trimethylbenzoyl) phenylphosphine Acylphosphine oxide compounds such as oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-ketor compounds such as 1-hydroxycyclohexylphenylketone; azo Azo compounds such as bisisobutyronitrile; titanosen compounds such as titanosen; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane 2-Hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone; 2-chloroanthraquinone and the like.
Further, as the photopolymerization initiator, for example, a quinone compound such as 1-chloroanthraquinone; a photosensitizer such as amine can be used.

The photopolymerization initiator contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

When a photopolymerization initiator is used, the content of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-1) is 0.01 to 20 mass by mass with respect to 100 parts by mass of the content of the energy ray-curable compound. The amount is preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The pressure-sensitive adhesive composition (I-1) may contain other additives that do not fall under any of the above-mentioned components as long as the effects of the present invention are not impaired.
Examples of the other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers (fillers), rust preventives, colorants (pigments, dyes), sensitizers, and tackifiers. , Known additives such as reaction retarders and cross-linking accelerators (catalysts).
The reaction retarder means that, for example, due to the action of the catalyst mixed in the pressure-sensitive adhesive composition (I-1), an unintended cross-linking reaction occurs in the pressure-sensitive adhesive composition (I-1) during storage. It suppresses the progress. Examples of the reaction retarder include those that form a chelate complex by chelating to a catalyst, and more specifically, those having two or more carbonyl groups (-C (= O)-) in one molecule. Can be mentioned.

The other additives contained in the pressure-sensitive adhesive composition (I-1) may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

When other additives are used, the content of the other additives in the pressure-sensitive adhesive composition (I-1) is not particularly limited and may be appropriately selected depending on the type thereof.

[solvent]
The pressure-sensitive adhesive composition (I-1) may contain a solvent. Since the pressure-sensitive adhesive composition (I-1) contains a solvent, the suitability for coating on the surface to be coated is improved.

The solvent is preferably an organic solvent, and examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters such as ethyl acetate (for example, carboxylic acid esters); ethers such as tetrahydrofuran and dioxane; cyclohexane and n-. Examples thereof include aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as 1-propanol and 2-propanol.

As the solvent, for example, the solvent used in the production of the pressure-sensitive adhesive resin (I-1a) may be used as it is in the pressure-sensitive adhesive composition (I-1) without being removed from the pressure-sensitive adhesive resin (I-1a). However, the same or different type of solvent as that used in the production of the pressure-sensitive adhesive resin (I-1a) may be added separately during the production of the pressure-sensitive adhesive composition (I-1).

The solvent contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

When a solvent is used, the content of the solvent in the pressure-sensitive adhesive composition (I-1) is not particularly limited and may be appropriately adjusted.

<Adhesive composition (I-2)>
As described above, the pressure-sensitive adhesive composition (I-2) is an energy ray-curable pressure-sensitive adhesive resin in which an unsaturated group is introduced into the side chain of the non-energy ray-curable pressure-sensitive adhesive resin (I-1a). (I-2a) is contained.

[Adhesive resin (I-2a)]
The adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group.

In addition to the energy ray-polymerizable unsaturated group, the unsaturated group-containing compound can further bond with the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). It is a compound having a group.
Examples of the energy ray-polymerizable unsaturated group include a (meth) acryloyl group, a vinyl group (also known as an ethenyl group), an allyl group (also known as a 2-propenyl group), and the like, and a (meth) acryloyl group is preferable. ..
Examples of the group that can be bonded to the functional group in the adhesive resin (I-1a) include an isocyanate group and a glycidyl group that can be bonded to a hydroxyl group or an amino group, and a hydroxyl group and an amino group that can be bonded to a carboxy group or an epoxy group. And so on.

Examples of the unsaturated group-containing compound include (meth) acryloyloxyethyl isocyanate, (meth) acryloyl isocyanate, and glycidyl (meth) acrylate.

The pressure-sensitive adhesive resin (I-2a) contained in the pressure-sensitive adhesive composition (I-2) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. You can choose.

In the pressure-sensitive adhesive composition (I-2), the ratio of the content of the pressure-sensitive adhesive resin (I-2a) to the total mass of the pressure-sensitive adhesive composition (I-2) is preferably 5 to 99% by mass. , 10-95% by mass is more preferable, and 10-90% by mass is particularly preferable.

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer similar to that in the adhesive resin (I-1a) is used as the adhesive resin (I-2a), for example, the pressure-sensitive adhesive composition ( I-2) may further contain a cross-linking agent.

Examples of the cross-linking agent in the pressure-sensitive adhesive composition (I-2) include the same cross-linking agents as those in the pressure-sensitive adhesive composition (I-1).
The cross-linking agent contained in the pressure-sensitive adhesive composition (I-2) may be only one type, two or more types, and when two or more types, the combination and ratio thereof can be arbitrarily selected.

When a cross-linking agent is used, the content of the cross-linking agent in the pressure-sensitive adhesive composition (I-2) is 0.01 to 50 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-2a). It is preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass.

[Photopolymerization initiator]
The pressure-sensitive adhesive composition (I-2) may further contain a photopolymerization initiator. The pressure-sensitive adhesive composition (I-2) containing a photopolymerization initiator sufficiently undergoes a curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-2) include the same photopolymerization initiators in the pressure-sensitive adhesive composition (I-1).
The photopolymerization initiator contained in the pressure-sensitive adhesive composition (I-2) may be only one type, two or more types, and when two or more types, the combination and ratio thereof can be arbitrarily selected.

When a photopolymerization initiator is used, the content of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-2) is 0.01 to 100 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-2a). The amount is preferably 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The pressure-sensitive adhesive composition (I-2) may contain other additives that do not fall under any of the above-mentioned components as long as the effects of the present invention are not impaired.
Examples of the other additive in the pressure-sensitive adhesive composition (I-2) include the same as the other additives in the pressure-sensitive adhesive composition (I-1).
The other additives contained in the pressure-sensitive adhesive composition (I-2) may be only one type, may be two or more types, and when there are two or more types, their combinations and ratios can be arbitrarily selected.

When other additives are used, the content of the other additives in the pressure-sensitive adhesive composition (I-2) is not particularly limited and may be appropriately selected depending on the type thereof.

[solvent]
The pressure-sensitive adhesive composition (I-2) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).
Examples of the solvent in the pressure-sensitive adhesive composition (I-2) include the same solvents as those in the pressure-sensitive adhesive composition (I-1).
The solvent contained in the pressure-sensitive adhesive composition (I-2) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.
When a solvent is used, the content of the solvent in the pressure-sensitive adhesive composition (I-2) is not particularly limited and may be appropriately adjusted.

<Adhesive composition (I-3)>
As described above, the pressure-sensitive adhesive composition (I-3) contains the pressure-sensitive resin (I-2a) and an energy ray-curable compound.

In the pressure-sensitive adhesive composition (I-3), the ratio of the content of the pressure-sensitive adhesive resin (I-2a) to the total mass of the pressure-sensitive adhesive composition (I-3) is preferably 5 to 99% by mass. , 10-95% by mass is more preferable, and 15-90% by mass is particularly preferable.

[Energy ray curable compound]
Examples of the energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-3) include monomers and oligomers having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays, and the pressure-sensitive adhesive composition. Examples thereof include the same energy ray-curable compounds contained in the substance (I-1).
The energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected. ..

In the pressure-sensitive adhesive composition (I-3), the content of the energy ray-curable compound is 0.01 to 300 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-2a). It is preferably 0.03 to 200 parts by mass, and particularly preferably 0.05 to 100 parts by mass.

[Photopolymerization initiator]
The pressure-sensitive adhesive composition (I-3) may further contain a photopolymerization initiator. The pressure-sensitive adhesive composition (I-3) containing a photopolymerization initiator sufficiently undergoes a curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-3) include the same photopolymerization initiators in the pressure-sensitive adhesive composition (I-1).
The photopolymerization initiator contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

When a photopolymerization initiator is used, the content of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-3) is 100 parts by mass in total of the pressure-sensitive adhesive resin (I-2a) and the energy ray-curable compound. On the other hand, the amount is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The pressure-sensitive adhesive composition (I-3) may contain other additives that do not fall under any of the above-mentioned components as long as the effects of the present invention are not impaired.
Examples of the other additive include the same as the other additive in the pressure-sensitive adhesive composition (I-1).
The other additives contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and when there are two or more types, their combinations and ratios can be arbitrarily selected.

When other additives are used, the content of the other additives in the pressure-sensitive adhesive composition (I-3) is not particularly limited and may be appropriately selected depending on the type thereof.

[solvent]
The pressure-sensitive adhesive composition (I-3) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).
Examples of the solvent in the pressure-sensitive adhesive composition (I-3) include the same solvents as those in the pressure-sensitive adhesive composition (I-1).
The solvent contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.
When a solvent is used, the content of the solvent in the pressure-sensitive adhesive composition (I-3) is not particularly limited and may be appropriately adjusted.

<Adhesive compositions other than adhesive compositions (I-1) to (I-3)>
Up to this point, the pressure-sensitive adhesive composition (I-1), the pressure-sensitive adhesive composition (I-2), and the pressure-sensitive adhesive composition (I-3) have been mainly described, but those described as the components contained therein have been described. General pressure-sensitive adhesive compositions other than these three types of pressure-sensitive adhesive compositions (referred to in this specification as "pressure-sensitive adhesive compositions other than pressure-sensitive adhesive compositions (I-1) to (I-3)") However, it can be used in the same way.

Examples of the pressure-sensitive adhesive composition other than the pressure-sensitive adhesive compositions (I-1) to (I-3) include non-energy ray-curable pressure-sensitive adhesive compositions in addition to the energy-ray-curable pressure-sensitive adhesive composition.
Examples of the non-energy ray-curable pressure-sensitive adhesive composition include non-energy ray-curable resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins. Examples thereof include a pressure-sensitive adhesive composition (I-4) containing a sex-sensitive pressure-sensitive resin (I-1a), and those containing an acrylic resin are preferable.

The pressure-sensitive adhesive compositions other than the pressure-sensitive adhesive compositions (I-1) to (I-3) preferably contain one or more cross-linking agents, and the content thereof is the above-mentioned pressure-sensitive adhesive composition. The same can be applied to the case of (I-1) and the like.

<Adhesive composition (I-4)>
Preferred pressure-sensitive adhesive compositions (I-4) include, for example, those containing the pressure-sensitive adhesive resin (I-1a) and a cross-linking agent.

[Adhesive resin (I-1a)]
Examples of the adhesive resin (I-1a) in the pressure-sensitive adhesive composition (I-4) include the same adhesive resin (I-1a) as in the pressure-sensitive adhesive composition (I-1).
The pressure-sensitive adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-4) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. You can choose.

In the pressure-sensitive adhesive composition (I-4), the ratio of the content of the pressure-sensitive adhesive resin (I-1a) to the total mass of the pressure-sensitive adhesive composition (I-4) is preferably 5 to 99% by mass. , 10-95% by mass is more preferable, and 15-90% by mass is particularly preferable.

In the pressure-sensitive adhesive composition (I-4), the ratio of the content of the pressure-sensitive resin (I-1a) to the total content of all components other than the solvent (that is, with respect to the total mass of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive layer). , The content ratio of the adhesive resin (I-1a)) is preferably 50 to 98% by mass, and may be any of, for example, 65 to 98% by mass and 80 to 98% by mass. ..

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth) acrylic acid alkyl ester is used as the adhesive resin (I-1a), the pressure-sensitive adhesive composition ( I-4) preferably further contains a cross-linking agent.

Examples of the cross-linking agent in the pressure-sensitive adhesive composition (I-4) include the same cross-linking agents as those in the pressure-sensitive adhesive composition (I-1).
The cross-linking agent contained in the pressure-sensitive adhesive composition (I-4) may be only one type, may be two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-4), the content of the cross-linking agent is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-1a). It is more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass.

[Other additives]
The pressure-sensitive adhesive composition (I-4) may contain other additives that do not fall under any of the above-mentioned components as long as the effects of the present invention are not impaired.
Examples of the other additive include the same as the other additive in the pressure-sensitive adhesive composition (I-1).
The other additives contained in the pressure-sensitive adhesive composition (I-4) may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

When other additives are used, the content of the other additives in the pressure-sensitive adhesive composition (I-4) is not particularly limited and may be appropriately selected depending on the type thereof.

[solvent]
The pressure-sensitive adhesive composition (I-4) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).
Examples of the solvent in the pressure-sensitive adhesive composition (I-4) include the same solvents as those in the pressure-sensitive adhesive composition (I-1).
The solvent contained in the pressure-sensitive adhesive composition (I-4) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.
When a solvent is used, the content of the solvent in the pressure-sensitive adhesive composition (I-4) is not particularly limited and may be appropriately adjusted.

<< Manufacturing method of adhesive composition >>
The pressure-sensitive adhesive compositions other than the pressure-sensitive adhesive compositions (I-1) to (I-3) and the pressure-sensitive adhesive compositions (I-1) to (I-3) such as the pressure-sensitive adhesive composition (I-4) , The pressure-sensitive adhesive and, if necessary, components other than the pressure-sensitive adhesive, and the like, are obtained by blending each component for forming a pressure-sensitive adhesive composition.
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 adding and mixing each component may be appropriately adjusted in consideration of the conditions under which each compounding component is unlikely to deteriorate, but the temperature is preferably 15 to 30 ° C.

-Method of manufacturing a composite sheet for forming a protective film The composite sheet for forming a protective film can be manufactured by 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, when the pressure-sensitive adhesive layer is laminated on the base material when the support sheet is manufactured, the above-mentioned pressure-sensitive adhesive composition may be applied onto the base material and dried if necessary.

On the other hand, for example, when a protective film-forming film is further laminated on the pressure-sensitive adhesive layer already laminated on the base material, the protective film-forming composition is applied on the pressure-sensitive adhesive layer to form a protective film. It is possible to directly form a forming film. Layers other than the protective film-forming film can also be laminated on the pressure-sensitive adhesive layer in the same manner by using the composition for forming this layer. As described above, when a continuous two-layer laminated structure is formed by using any of the compositions, the composition is further applied on the layer formed from the composition to form a new layer. It is possible to form.
However, of these two layers, the layer to be laminated afterwards is formed in advance on another release film using the composition, and the side of the formed layer in contact with the release film is It is preferable to form a laminated structure of two continuous layers by laminating the exposed surface on the opposite side with the exposed surface of the remaining layers that have already been formed. At this time, it is preferable that the composition is applied to the peeled surface of the release film. The release film may be removed if necessary after the laminated structure is formed.

For example, a protective film-forming composite sheet in which an adhesive layer is laminated on a base material and a protective film-forming film is laminated on the pressure-sensitive adhesive layer (in other words, a support sheet is a laminate of a base material and an adhesive layer). In the case of producing a protective film-forming composite sheet), the pressure-sensitive adhesive composition is applied onto the base material and dried as necessary to laminate the pressure-sensitive adhesive layer on the base material. Separately, the protective film-forming composition is applied onto the release film and dried if necessary to form the protective film-forming film on the release film. Then, the exposed surface of the protective film forming film is bonded to the exposed surface of the pressure-sensitive adhesive layer already laminated on the base material, and the protective film-forming film is laminated on the pressure-sensitive adhesive layer to form the protective film. Composite sheet for use is obtained.

When laminating the pressure-sensitive adhesive layer on the base material, the pressure-sensitive adhesive composition is coated on the release film instead of the method of coating the pressure-sensitive adhesive composition on the base material as described above. An adhesive layer is formed on the release film by drying as necessary, and the exposed surface of this layer is bonded to one surface of the base material to form an adhesive layer on the base material. It may be laminated.
In either method, the release film may be removed at an arbitrary timing after the desired laminated structure is formed.

As described above, all the layers (adhesive layer, protective film forming film, adhesive layer for jig) other than the base material constituting the protective film forming composite sheet are formed in advance on the release film. Since it can be laminated by a method of adhering it to the surface of a target layer, a layer that employs such a step may be appropriately selected as necessary to produce a composite sheet for forming a protective film.
Further, each layer constituting the protective film forming composite sheet and the protective film forming composite sheet may be punched into a desired shape, if necessary.

The protective film-forming composite sheet is usually stored in a state where a release film is attached to the surface of the outermost layer (for example, the protective film-forming film) on the opposite side of the support sheet. Therefore, a composition for forming a layer constituting the outermost layer, such as a composition for forming a protective film, is applied onto the release film (preferably the release-treated surface thereof), and the composition is dried if necessary. Then, a layer constituting the outermost layer is formed on the release film, and the remaining layers are laminated on the exposed surface on the side opposite to the side in contact with the release film of this layer by any of the above methods. However, a composite sheet for forming a protective film can also be obtained by leaving the release film in a bonded state without removing it.

-Method for manufacturing a chip with a protective film The method for manufacturing a chip with a protective film according to an embodiment of the present invention is the heat-curable protective film in the heat-curable protective film-forming film or the protective film-forming composite sheet. A step of forming a laminate by sticking a forming film to a wafer or a chip (hereinafter, may be abbreviated as "sticking step").
By expanding the laminate at a temperature of less than 23 ° C. (preferably less than 15 ° C.), the wafer and the film for forming the thermosetting protective film are divided, or the thermosetting protection attached to the chip is attached. The process of dividing the film-forming film (hereinafter sometimes abbreviated as "division process") and
A step of forming a protective film on the chip by heat-curing the divided thermosetting protective film forming film (hereinafter, may be abbreviated as "protective film forming step") is provided.
Hereinafter, the method for manufacturing a chip with a protective film according to an embodiment of the present invention is also simply referred to as a "method for manufacturing a chip with a protective film".

The wafer may be one in which a modified layer is formed inside the wafer by irradiating the inside of the wafer with laser light.
In such a case, the method for manufacturing a chip with a protective film is a step of irradiating the inside of the wafer with a laser beam to form a modified layer inside the wafer (hereinafter, abbreviated as "modified layer forming step"). A wafer having a modified layer formed therein may be obtained. Further, in the dividing step, the wafer on which the modified layer is formed is expanded together with the thermosetting protective film forming film toward the surface of the protective film forming film to protect the thermosetting film. It may be a step of cutting the film-forming film and dividing the wafer at the site of the modified layer.

The method for producing a chip with a protective film may include a modified layer forming step, a dividing step, and a protective film forming step in this order after the sticking step. An example of a method for manufacturing the chip with a protective film will be described with reference to FIG.
In the following embodiments, a case where a semiconductor wafer or a semiconductor chip is used as the wafer or chip will be described, and a method for manufacturing a chip with a protective film may be referred to as a "method for manufacturing a semiconductor chip with a protective film".

FIG. 4 is a cross-sectional view schematically showing an example of a method for manufacturing a chip with a protective film.
First, the back surface of the semiconductor wafer 18 is ground to a desired thickness, and then the back surface of the semiconductor wafer 18 after back surface grinding is attached to the heat-curable protective film forming film 23 of the protective film forming composite sheet 2. The composite sheet 2 for forming a protective film is fixed to the ring frame 17 (FIG. 4A). When the back grind tape 20 is attached to the surface (electrode forming surface) of the semiconductor wafer 18, the back grind tape 20 is removed from the semiconductor wafer 18.

In the protective film forming film of the embodiment, the wafer is attached to the heat-curable protective film forming film because the storage elasticity E'is 5 MPa or more at all temperatures in the temperature range of 23 ° C. or higher and lower than 80 ° C. It is possible to further prevent the protective film-forming film from seeping out due to excessive flow of the protective film-forming film (exuding from the edge of the wafer or chip).

Next, a laser beam is irradiated from the side of the protective film forming composite sheet 2 so as to focus on the focal point set inside the semiconductor wafer 18 (SD) (FIG. 4 (b)), and the inside of the semiconductor wafer 18 is subjected to. The modified layer 18c is formed. Further, if necessary, laser light is irradiated from the side of the support sheet 10 to perform laser printing.

Next, the semiconductor wafer 18 is moved to a low temperature environment together with the protective film-forming composite sheet 2 attached to the back surface, and is cool-expanded (CE) in the plane direction of the protective film-forming composite sheet 2 to obtain a thermosetting protective film. The forming film is cut, and the semiconductor wafer 18 is divided and individualized at the site of the modified layer 18c (FIG. 4 (c)). The temperature condition of Cool Expand (CE) may be lower than room temperature, but may be lower than 23 ° C, lower than 15 ° C, may be -20 to 10 ° C, and -15 to 15 ° C. It may be 5 ° C. If necessary, an infrared camera is used to perform an infrared inspection from the side of the support sheet 10.

Here, in view of the fact that the thermosetting protective film forming film according to the embodiment has a storage elastic modulus E'of 3000 MPa or less at all temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C., cool expand (CE). ) May be less than 23 ° C. or less than 15 ° C.

The protective film forming film of the embodiment has a storage elastic modulus E'of 3000 MPa or less at all temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C., so that the protective film forming film in the dividing step has breakability. It will be better.

Further, if necessary, a fixing jig may be attached to the expanded support sheet 10 (that is, the base material 11 and the pressure-sensitive adhesive layer 12) to fix the support sheet 10 in the expanded state. Alternatively, the support sheet 10 is cool-expanded by imparting heat shrinkage (heat shrinkability) to the base material 11, and then supported by utilizing the heat shrinkage (heat shrinkage) of the base material 11. It is also possible to fix the support sheet 10 in an expanded state without attaching a fixing jig except for the slack of the sheet 10. When the pressure-sensitive adhesive layer 12 is energy ray-curable, the pressure-sensitive adhesive layer 12 is cured by irradiating the energy ray after fixing the expanded support sheet 10 by attaching a fixing jig or the like. After the pressure-sensitive adhesive layer 12 is cured, it is preferable to move to the next step of curing the thermosetting protective film forming film 23.

Further, the laminate of the support sheet 10, the individualized film 23 for forming a thermosetting protective film, and the individualized semiconductor chip 19 is heated (FIG. 4 (d)) to provide thermosetting protection. The film-forming film 23 is cured to form a protective film 23'.

The protective film forming film of the embodiment has a storage elastic modulus E'of 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower, and thus undergoes a protective film forming step after the dividing step. Is formed, the generation of central marks on the protective film can be suppressed.

Finally, the semiconductor chip 19 is peeled off from the support sheet 10 together with the protective film 23'attached to the back surface thereof and picked up to obtain the semiconductor chip 19 with the protective film 23'(FIG. 4 (e)). When the pressure-sensitive adhesive layer 12 is energy ray-curable, if necessary, the pressure-sensitive adhesive layer 12 is cured by irradiation with energy rays, and the semiconductor chip 19 is placed on the back surface of the cured pressure-sensitive adhesive layer 12. By picking up together with the attached protective film 23', the semiconductor chip 19 with the protective film 23' can be obtained more easily.

The mechanism by which the central mark is generated is not clear, but it is inferred as follows. In the method for manufacturing a chip with a protective film, when the support sheet 10 is expanded in the "splitting process", the support sheet 10 is supported by applying a force in the direction from the center to the outside in the surface direction thereof. It is considered that residual stress is generated in the sheet 10. When the entire protective film forming composite sheet 2 is heated in the subsequent "protective film forming step", the pressure-sensitive adhesive layer 12 and the thermosetting protective film forming film 23 become high in temperature to increase the fluidity, and the support sheet 10 Of these, the residual stress remaining in the pressure-sensitive adhesive layer 12 causes the portion of the protective film forming film 23 in contact with the pressure-sensitive adhesive layer 12 to be pulled outward from the center of the chip and deformed, and the protective film is formed in the deformed state. It is considered that the film 23 is cured and a mark (center mark) is formed in the central portion of the protective film 23'after curing. Here, the protective film forming film of the embodiment is preferably deformed because the storage elastic modulus E'is 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower. It is considered that the occurrence of the central mark is suppressed.
It is effective that the protective film-forming composition contains a cross-linking agent as an example of a configuration for setting the storage elastic modulus E'to 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower. The details of the mechanism are not clear, but it is considered that the storage elastic modulus E'in the high temperature region is suitable, probably due to the higher-order structure formed by the cross-linking agent.

FIG. 4 illustrates an example of a method for manufacturing a semiconductor chip with a protective film using a protective film forming composite sheet 2 having a jig adhesive layer 16, but the jig adhesive layer 16 is provided. The same applies to an example of a method for manufacturing a semiconductor chip with a protective film using the composite sheet 1 for forming a protective film.

Further, in FIG. 4, a modified layer is irradiated inside the semiconductor wafer 18 by irradiating a laser beam (SD) from the side of the composite sheet 2 for forming the protective film so as to focus on the focal point set inside the semiconductor wafer 18. However, the present invention is not limited to this, and the modified layer forming step, the laminating step, the dividing step, and the protective film forming step may be provided in this order, specifically. For example, a modified layer may be formed inside the semiconductor wafer 18 to which the back grind tape 20 is attached, and the protective film forming composite sheet 2 may be attached to the semiconductor wafer 18 on which the modified layer is formed. After that, the semiconductor chip 19 with the protective film 23'is obtained by irradiating the support sheet 10 with laser light, performing laser printing, performing cool expanding (CE), thermosetting, infrared inspection, and picking up.

Further, FIG. 4 illustrates a method of dividing both the semiconductor wafer 18 on which the modified layer is formed and the protective film forming film 23 in the dividing step, but a plurality of pre-divided semiconductor chips And the thermosetting protective film forming film are bonded together, and in the subsequent dividing step, only the protective film forming film may be divided. As a method of obtaining a plurality of divided semiconductor chips, for example, a method of grinding the back surface of a semiconductor wafer on which a modified layer is formed and dividing the semiconductor wafer at a site where the modified layer is formed by a force at the time of grinding is used. Can be mentioned.

◎ After the device manufacturing method, the obtained chip with a protective film (for example, a semiconductor chip) is flip-chip connected to the circuit surface of the board with the protective film attached by the same method as the conventional method. After that, it can be made into a package (for example, a semiconductor package). Then, the target device (for example, a semiconductor device) may be manufactured using this package.

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.

<Manufacturing of composite sheet for forming protective film>
(Manufacturing raw material for the protective film forming composition (III-1))
The components used in the production of the protective film forming composition are shown below.
Polymer component (A): Acrylic polymer obtained by copolymerizing 90 parts by mass of methyl acrylate and 10 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 400,000. Tg: 7 ° C.)
-Epoxy resin (B1) -1: Bisphenol A type epoxy resin (jER828 manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 184 to 194 g / eq)
(B1) -2: Bisphenol A type epoxy resin (jER1055 manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 800 to 900 g / eq)
(B1) -3: Dicyclopentadiene type epoxy resin (Epoxy HP-7200HH manufactured by DIC Corporation, epoxy equivalent 255-260 g / eq)
-Curing agent (B2): dicyandiamide (DICY7 manufactured by Mitsubishi Chemical Corporation, active hydrogen amount 21 g / eq)
-Curing accelerator (C): 2-phenyl-4,5-dihydroxymethylimidazole (Curesol 2PHZ manufactured by Shikoku Chemicals Corporation)
-Filler (D): Silica filler (SC205G-MMQ manufactured by Admatex, average particle size 0.3 μm)
-Coupling agent (E): Silane coupling agent (X-41-1056 manufactured by Shin-Etsu Chemical Co., Ltd.)
Cross-linking agent (F) -1: Trimethylolpropane adduct of xylylene diisocyanate (Takenate (registered trademark) D-110N manufactured by Mitsui Chemicals, Inc.)
(F) -2: Trimethylolpropane adduct of tolylene diisocyanate (manufactured by Tosoh Corporation, Coronate L)
-Colorant (I): Three-color mixed pigment (D1201M manufactured by Sanyo Pigment, solid content concentration 30% by mass)

[Examples 1 to 5 and Comparative Examples 1 to 2]
(Production of composition for forming a protective film (III-1))
Polymer component (A), epoxy resin (B1) -1, epoxy resin (B1) -2, epoxy resin (B1) -3, curing agent (B2), curing accelerator (C), filler (D), The contents (solid content, parts by mass) of the coupling agent (E), the cross-linking agent (F) -1, the cross-linking agent (F) -2, and the colorant (I) are shown in Table 1 (solid). The composition (III-1) for forming a protective film having a solid content concentration of 50% by mass was prepared by dissolving or dispersing in methyl ethyl ketone so as to have a mass ratio) and stirring at 23 ° C. In addition, the description of "-" in the column of the contained component in Table 1 means that the protective film forming composition (III-1) does not contain the component.

(Manufacturing of Adhesive Composition (I-4))
Polymer component (meth) Acrylate ester copolymer (2-ethylhexyl acrylate (2EHA) 80 parts by mass, 2-hydroxyl ethyl acrylate (HEA) 20 parts by mass copolymer obtained by copolymerizing. Weight average molecular weight. : 800,000)
-Crosslinking agent component Trimethylolpropane adduct of xylylene diisocyanate (manufactured by Mitsui Chemicals, Inc., Takenate (registered trademark) D-110N)

Non-energy ray-curable with a solid content concentration of 25% by mass, containing a polymer component (100 parts by mass, solid content) and a cross-linking agent component (18 parts by mass, solid content), and further containing methyl ethyl ketone as a solvent. A pressure-sensitive adhesive composition (I-4) was prepared.

(Manufacturing of support sheet)
A release film (“SP-PET38131” manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film was peeled by a silicone treatment was used, and the pressure-sensitive adhesive composition obtained above was used on the peeled surface. I-4) was applied and dried by heating at 120 ° C. for 2 minutes to form a non-energy ray-curable pressure-sensitive adhesive layer having a thickness of 10 μm.
Next, by laminating a polypropylene film (thickness 80 μm) as a base material on the exposed surface of the pressure-sensitive adhesive layer, the base material, the pressure-sensitive adhesive layer and the release film are laminated in this order in these thickness directions. I got a support sheet.

(Manufacturing of composite sheet for forming protective film)
A release film (second release film, "SP-PET382150" manufactured by Lintec Corporation, thickness 38 μm) obtained by peeling one side of a polyethylene terephthalate film by a silicone treatment was used, and the peeled surface was obtained as described above. The protective film-forming composition (III-1) was applied and dried at 100 ° C. for 2 minutes to produce a thermosetting protective film-forming film having a thickness of 15 μm.
Further, the exposed surface of the obtained protective film forming film on the side not provided with the second release film is subjected to a release treatment of the release film (first release film, Lintec's "SP-PET38131", thickness 38 μm). By laminating the surfaces, a laminated film having a first release film on one surface of the protective film forming film and a second release film on the other surface was obtained, and then the laminated film was formed into a circular shape.

Then, the release film was removed from the pressure-sensitive adhesive layer of the support sheet obtained above. Moreover, the first release film was removed from the laminated film obtained above. Then, by adhering the exposed surface of the pressure-sensitive adhesive layer formed by removing the release film and the exposed surface of the protective film forming film formed by removing the first release film, the base material and the adhesive are adhered. A protective film-forming composite sheet was prepared in which the agent layer, the protective film-forming film, and the second release film were laminated in this order in these thickness directions. The diameter of the protective film forming film was 310 mm.

(Measurement of thickness)
The measurement was performed using a constant pressure thickness measuring device (manufactured by Teclock Co., Ltd., product name "PG-02").

<Evaluation>
(Dynamic viscoelasticity evaluation of protective film forming film (storage elastic modulus E'))
The protective film-forming composition (III-1) is applied to a release film and dried (drying conditions: 100 ° C. for 2 minutes) to form a protective film-forming film having a thickness of 15 μm. Got 16 layers of this protective film forming film were laminated to obtain a laminated body having a width of 4 mm, a length of 22 mm, and a thickness of 240 μm, which was used as a measurement sample of the protective film forming film.
The storage elastic modulus E'of the protective film forming film is a tensile method (tensile mode) using a dynamic viscoelastic automatic measuring device (Leovibron DDV-01FP manufactured by A & D Co., Ltd.), and a distance between chucks: 20 mm. The storage elastic modulus E'from −10 ° C. to 140 ° C. was measured under the measurement conditions of frequency: 11 Hz, temperature rise rate: 3 ° C./min, and constant rate temperature rise. Among them, the values of the storage elastic modulus E'at around 0 ° C., around 23 ° C., around 80 ° C., and around 130 ° C. were obtained.

(Confirmation of splittability, exudation, and central marks)
On the ground surface of a silicon wafer (diameter: 12 inches, thickness: 150 μm, ground surface: # 2000) with a back grind tape that has been ground on the back side, the protective film forming film surface of the protective film forming composite sheet is attached to the tape mounter. It was attached while heating at 70 ° C. using (ADWILL RAD-2700 manufactured by Lintec Corporation). After peeling off the back grind tape, the silicon wafer is irradiated with a laser beam having a wavelength of 1342 nm from the opposite side of the grinding surface using a laser saw (DFL7361 manufactured by Disco Corporation), and the chip size is inside the silicon wafer. The modified layer was formed so that the size was 5 mm × 5 mm. Next, using an expander (Disco, DDS2300), cool expand the silicon wafer at a push-up height of 16 mm, a push-up speed of 100 mm / s, and a temperature of 0 ° C., and piece the silicon wafer into a 5 mm × 5 mm chip. The film for forming a protective film was cut off. Then, while rotating the heater at a heater rotation speed of 1 ° / sec, the composite sheet for forming the protective film is heat-shrinked to remove the slack of the support sheet and maintain the expanded state at 130 ° C., 2 Heat curing was performed under the condition of time, and the protective film-forming film was used as a protective film. Then, the adhesive sheet was attached to the side opposite to the support sheet (that is, the chip side).

The chip was peeled off from the support sheet and the protective film was observed. By the work of attaching the adhesive sheet, it was possible to observe the protective film without the individualized chips falling apart even if the support sheet was peeled off. The protective film was observed (magnification 100 times) using a digital microscope (Digital Microscope VHX-1000 manufactured by Keyence Co., Ltd.), and the "breakability" of the protective film forming film and the "bleeding out" of the protective film forming film were observed. , And the presence or absence of a "center mark" on the protective film was evaluated.

・ Dividability:
〇 ... Of the 10 chips tested, no uncut portion of the protective film forming film was confirmed.
Δ: Of the 10 chips tested, at least one chip had an uncut portion of the protective film forming film.
X ... Of the 10 chips tested, unbroken portions of the protective film forming film were generated in all the chips.

・ Exudation:
〇 ... Of the 10 chips tested, no exudation of the protective film forming film was confirmed.
Δ: Of the 10 chips tested, at least one chip had exudation of the protective film forming film.
X ... Of the 10 chips tested, exudation of the protective film forming film occurred in all the chips.

・ Center mark:
〇 ... Of the 10 chips tested, no center mark was found on the protective film.
Δ: Of the 10 chips tested, at least one chip had a central mark on the protective film.
X ... Of the 10 chips tested, center marks were generated on the protective film in all the chips.

The results are shown in Table 2.

No center marks were confirmed in the protective film forming films of Examples 1 to 5 in which the storage elastic modulus E'satisfied with the regulation of 2 MPa or more at all temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower. ..
On the other hand, in the protective film forming films of Comparative Examples 1 and 2, in which the storage elastic modulus E'does not satisfy the regulation of 2 MPa or more at all the temperatures in the temperature range of 80 ° C. or higher and 130 ° C. or lower, the center mark is generated. confirmed. FIG. 5 shows a schematic view of an observation image of the confirmed center mark acquired by an optical interference type surface roughness meter (manufactured by Veeco, product name: Wyko NT1100). 5 (b) is a cross-sectional view of FIG. 5 (a). As shown in FIG. 5, a center mark 25 was formed on the protective film 23'of the semiconductor chip 19 with the protective film 23'.

Further, in the protective film-forming composite sheets of Examples 1 to 5 in which the storage elastic modulus E'satisfies the regulation of 5 MPa or more at all temperatures in the temperature range of 23 ° C. or higher and lower than 80 ° C., the protective film-forming film is used. No exudation was confirmed.

Further, in the protective film forming composite sheet of Examples 1 to 4, which satisfies the regulation that the storage elastic modulus E'is 3000 MPa or less at all the temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C., the protective film forming film is used. The splittability was better.

The value of the storage elastic modulus E'was correlated with the content of the cross-linking agent. In this embodiment, since the protective film forming film contains a cross-linking agent, the value of the storage elastic modulus E'of the protective film forming film can be easily adjusted to a value capable of suppressing the generation of center marks. there were.

Each configuration and a combination thereof in each embodiment is an example, and the configuration can be added, omitted, replaced, and other changes are possible without departing from the spirit of the present invention. Moreover, the present invention is not limited to each embodiment, but is limited only to the scope of claims.

The present invention can be used in the manufacture of semiconductor devices.

1, 2, ... Composite sheet for forming a protective film, 10 ... Support sheet, 10a ... Surface of support sheet, 11 ... Base material, 11a ... Surface of base material, 12 ... Adhesive Agent layer, 12a ... Surface of adhesive layer, 13, 23 ... Film for forming a heat-curable protective film, 13a, 23a ... Surface of film for forming a heat-curable protective film, 13b ... Protection Surface of film forming film (second surface), 23'... protective film, 25 ... center mark, 15 ... release film, 15a ... surface of release film, 151 ... first release Film, 152 ... 2nd release film, 16 ... Adhesive layer for jig, 16a ... Surface of adhesive layer for jig, 17 ... Ring frame, 18 ... Semiconductor wafer (silicon) Wafer), 18a ... Back surface of semiconductor wafer, 18c ... Modified layer, 19 ... Semiconductor chip, 20 ... Back grind tape, SD ... Laser light irradiation, CE ... Cool expand

Claims (13)

A film for forming a thermosetting protective film, which is used by being attached to the back surface of a wafer or a chip .
At all temperatures in the temperature range of 80 ° C. or higher 130 ° C. or less, measured at a tension mode, the storage modulus before thermal curing E 'is Ri der least 2 MPa,
At all temperatures in the temperature range of less than 80 ° C. 23 ° C. or higher were measured at a tensile mode, storage elastic modulus before thermal curing E 'is Ru der least 5 MPa, thermosetting protective film forming film. The thermosetting protective film formation according to claim 1, wherein the storage elastic modulus E'before thermosetting measured in the tensile mode is 3000 MPa or less at all temperatures in the temperature range of 0 ° C. or higher and lower than 23 ° C. Film for. A film for forming a thermosetting protective film, which is used by being attached to the back surface of a wafer or a chip .
At all temperatures in the temperature range of 80 ° C. or higher 130 ° C. or less, measured at a tension mode, the storage modulus before thermal curing E 'is Ri der least 2 MPa,
At 0 all temperatures temperature range below ° C. or higher 23 ° C., was measured at a tension mode, the storage modulus before thermal curing E 'is Ru der less 3000 MPa, thermosetting protective film forming film. A cross-linking agent (a) in which the protective film forming film has a polymer component (A) having a structural unit containing a functional group (a1) and two or more functional groups (f1) that react with the functional group (a1). The thermosetting protective film forming film according to any one of claims 1 to 3 , which contains F). The thermosetting protective film forming film according to claim 4 , wherein the content of the structural unit containing the functional group (a1) is 3 parts by mass or more with respect to 100 parts by mass of the polymer component (A). .. The thermosetting protective film forming film according to claim 4 or 5 , wherein the content of the functional group (f1) is 0.005 to 4 equivalents with respect to 1 equivalent of the functional group (a1). The thermosetting protective film forming film according to any one of claims 4 to 6 , wherein the functional group (f1) is an isocyanate group and the functional group (a1) is a hydroxyl group. The protective film forming film has a storage elastic modulus E'(E'(80)) before heat curing measured in a tensile mode at any temperature in the temperature range of 80.0 to 80.5 ° C. E'(E'(130)), which is the ratio to the storage elastic modulus E'(E'(130)) before heat curing, measured in the tensile mode at any temperature in the temperature range of 129.5 to 130.0 ° C. The film for forming a thermosetting protective film according to any one of claims 1 to 7, wherein the value of (80) / E'(130) is 0.3 to 3. The film for forming a thermosetting protective film according to any one of claims 1 to 8, which has a thickness of 1 to 100 μm. The protective film forming film contains a polymer component (A) and a thermosetting component (B).
The polymer component (A) is an acrylic resin.
The thermosetting protective film according to any one of claims 1 to 9, wherein the thermosetting component (B) is an epoxy-based thermosetting resin composed of an epoxy resin (B1) and a thermosetting agent (B2). Forming film. A support sheet and a film for forming a thermosetting protective film according to any one of claims 1 to 10 are provided.
A composite sheet for forming a protective film, wherein the film for forming a thermosetting protective film is provided on the support sheet. A wafer or a chip obtained by using the thermosetting protective film forming film according to any one of claims 1 to 10 or the thermosetting protective film forming film in the protective film forming composite sheet according to claim 11. The process of forming a laminate by pasting it on the back surface of
By expanding the laminate at a temperature of less than 23 ° C., the wafer and the thermosetting protective film forming film are divided, or the thermosetting protective film forming film attached to the chip is divided. Process and
A method for producing a chip with a protective film, comprising a step of forming a protective film on the chip by heat-curing the divided film for forming a thermosetting protective film. The wafer is obtained by irradiating the inside of the wafer with laser light to form a modified layer inside the wafer.
The step of dividing the thermosetting protective film forming film expands the wafer on which the modified layer is formed together with the thermosetting protective film forming film toward the surface of the protective film forming film. The method for producing a chip with a protective film according to claim 12, wherein the step is a step of cutting the thermosetting protective film forming film and dividing the wafer at the site of the modified layer.

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