JP2023144840A - Support sheet and method for manufacturing workpiece processed product - Google Patents

Abstract

To provide a support sheet which includes a base material and an adhesive layer, which, even if the support sheet with a workpiece or workpiece processed product stuck thereon is heated, is capable of picking up the workpiece processed product normally from the support sheet, and, which, even if the support sheet fixed to a ring frame is heated, is capable of suppressing the peeling of the support sheet from the ring frame.SOLUTION: A support sheet 1 includes a base material 11 and an adhesive layer 12 formed on the base material 11. When the support sheet 1 is stuck on a SUS plate by the adhesive layer 12 and the adhesive layer 12 is heated at 130°C, an adhesive force (Y2) between the adhesive layer 12 and the SUS plate after heating is 13,000 mN/25 mm or more. When the support sheet 1 is stuck on a Si mirror wafer by the adhesive layer 12, and the adhesive layer is heated at 130°C to be energy ray-cured, an adhesive force (X1) between the cured product of the adhesive layer 12 and the Si mirror wafer is 400 mN/25 mm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a support sheet and a method for manufacturing a workpiece.

A support sheet is used when processing a workpiece such as a wafer and manufacturing a workpiece such as a chip. A typical support sheet includes a support sheet that includes a base material and an adhesive layer provided on one surface of the base material. The adhesive layer in the support sheet is attached, for example, to a workpiece to be processed, and the support sheet fixes the workpiece being processed. When the processing is dicing, the support sheet functions as a dicing sheet. The resulting workpiece is finally separated from the support sheet, picked up, and used in its intended application. At this time, if the adhesive layer is energy ray-curable, curing the adhesive layer with energy rays will reduce the adhesive force between the cured product and the workpiece. Easy to pick up.

A protective film-forming film for forming a protective film on the workpiece may be further provided on the surface of the adhesive layer opposite to the base material side, thereby forming a composite sheet for forming a protective film. . The protective film-forming film in the protective film-forming composite sheet is, for example, affixed to the workpiece to be processed, and the protective film-forming composite sheet fixes the workpiece being processed and also forms a protective film on the workpiece or workpiece. form. The resulting workpiece is finally picked up, separated from the support sheet with the protective film, and used in the intended application. Similarly to the above, when the adhesive layer is energy ray-curable, the work piece provided with the protective film can be easily picked up by curing the adhesive layer with energy rays.

On the other hand, the support sheet may be heated while the workpiece or workpiece is attached thereto. This heating may be performed, for example, to remove foreign matter such as a low molecular weight resin component adhering to the surface of the workpiece. In addition, it is sometimes performed to dry the workpiece after cleaning and removing fine foreign matter that is generated during processing such as dicing of the workpiece and adhering to the surface of the workpiece with water. These heatings are usually performed with the upper limit of the heating temperature being about 135°C. However, if the heat resistance of the support sheet is insufficient, heating the workpiece or the support sheet to which the workpiece is attached at such a temperature may ultimately make it impossible to pick up the workpiece from the support sheet. there were. Further, such heating of the support sheet may be performed while the support sheet is further fixed to the ring frame. In that case, at least a portion of the heated support sheet may peel off from the ring frame.

A support sheet that is heat resistant and suitable for heating includes a base material and an adhesive layer, and has a Young's modulus of the base material at 23 °C after heating at 120 °C for 4 hours, and a base material at 120 °C. A support sheet (workpiece processing sheet) in which the storage elastic modulus E' of the material is defined within a specific range is disclosed (see Patent Document 1).

JP 2021-119592 Publication

However, the support sheet disclosed in Patent Document 1 is not intended to be heated with an upper temperature limit of about 135°C. When the support sheet is heated under such conditions, it is not certain whether the workpiece can be normally picked up from the support sheet or whether the support sheet will be prevented from peeling off from the ring frame.

The present invention provides a support sheet comprising a base material and an adhesive layer, wherein the adhesive layer is energy ray curable, and when the support sheet to which a workpiece or workpiece is attached is heated. Even if the support sheet is fixed to the ring frame and is heated, the support sheet can be prevented from peeling off from the ring frame. The purpose is to provide sheets.

In order to solve the above problems, the present invention employs the following configuration.
[1]. A support sheet, the support sheet comprising a base material and an adhesive layer provided on one surface of the base material, the adhesive layer being energy ray curable, and the support sheet comprising: is pasted on the surface of a stainless steel plate using the adhesive layer, and the adhesive layer after pasting is heated at 130°C to increase the adhesive force (Y2) between the heated adhesive layer and the stainless steel plate. ), the adhesive force (Y2) is 13000 mN/25 mm or more, the support sheet is pasted on the mirror surface of a silicon mirror wafer with the adhesive layer, and the adhesive layer after pasting is heated at 130°C. to cure the adhesive layer after heating with energy rays, and measure the adhesive force (X1) between the energy ray-cured product of the adhesive layer and the silicon mirror wafer. A support sheet in which (X1) is 400 mN/25 mm or less.
[2]. The support sheet according to [1], wherein the adhesive layer contains an energy ray curable compound and an energy ray curable acrylic resin.
[3]. The support sheet is pasted on the surface of a stainless steel plate using the adhesive layer, the adhesive layer after pasting is heated at 130° C., the heated adhesive layer is cured with energy rays, and the adhesive layer is cured with energy rays. The support sheet according to [1] or [2], wherein the adhesive force (Y1) is 300 mN/25 mm or more when the adhesive force (Y1) between the energy ray cured product and the stainless steel plate is measured. .
[4]. The support sheet is pasted on the mirror surface of the silicon mirror wafer using the adhesive layer, and the adhesive layer after pasting is heated at 130° C., so that the adhesive layer after heating and the silicon mirror wafer are separated. The support sheet according to any one of [1] to [3], wherein the adhesive force (X2) is 13000 mN/25 mm or more when measured.

[5]. The support sheet was attached to the mirror surface of the silicon mirror wafer using the adhesive layer, and the silicon mirror wafer with the support sheet was stored for 30 minutes at a temperature of 23° C., and the adhesive layer was attached to the silicon mirror wafer. and the silicon mirror wafer, the adhesive force (X0) is 2000 mN/25 mm or more when measured, the adhesive force (X0) according to any one of [1] to [4]. support sheet.
[6]. A method for manufacturing a workpiece, the manufacturing method comprising: attaching the adhesive layer in the support sheet according to any one of [1] to [5] to a workpiece and a ring frame, a pasting step of fixing a workpiece with a support sheet, which includes the workpiece and the support sheet provided on the workpiece, to the ring frame; and after the pasting step, the support sheet is fixed to the ring frame. a heating step of heating the adhesive layer; and a processing step of producing the workpiece by processing the workpiece in the support sheet-attached workpiece fixed to the ring frame after the pasting step; After the heating step and the processing step, a curing step of curing the adhesive layer attached to the ring frame with energy rays, and after the curing step, separating the workpiece from the cured product of the adhesive layer and picking it up. A method for manufacturing a workpiece, comprising: a pick-up step.

According to the present invention, there is provided a support sheet comprising a base material and an adhesive layer, wherein the adhesive layer is energy ray curable, and the support sheet to which a workpiece or workpiece is attached is heated. Even when the support sheet is fixed to the ring frame and heated, it prevents the support sheet from peeling off from the ring frame. A support sheet that can be used is provided.

FIG. 1 is a cross-sectional view schematically showing an example of a support sheet according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating an example of a method for manufacturing a workpiece with a protective film according to an embodiment of the present invention.

◇Support Sheet A support sheet according to an embodiment of the present invention includes a base material and an adhesive layer provided on one surface of the base material, and the adhesive layer is energy ray curable. , the support sheet is pasted on the surface of the stainless steel plate by the adhesive layer, the adhesive layer after pasting is heated at 130°C, and the gap between the heated adhesive layer and the stainless steel plate is When the adhesive force (Y2) (herein sometimes simply referred to as "adhesive force (Y2)") is measured, the adhesive force (Y2) is 13000 mN/25 mm or more, and the support sheet is The adhesive layer is pasted onto the mirror surface of a silicon mirror wafer, the adhesive layer after pasting is heated at 130°C, the heated adhesive layer is cured with energy rays, and the adhesive layer is cured with energy rays. When the adhesive force (X1) (herein sometimes simply referred to as "adhesive force (X1)") between an object and the silicon mirror wafer is measured, the adhesive force (X1) is It is 400mN/25mm or less.

The support sheet of this embodiment can be used, for example, in manufacturing a workpiece, as described later.
The support sheet of this embodiment can constitute a protective film-forming composite sheet by laminating it with a protective film-forming film, for example, as described later.

The support sheet to which the work or workpiece is attached may be heated at a high temperature while being fixed to the ring frame. This heating may be performed, for example, to remove foreign matter such as a low molecular weight resin component adhering to the surface of the workpiece. In addition, it is sometimes performed to dry the workpiece after cleaning and removing fine foreign matter that is generated during processing such as dicing of the workpiece and adhering to the surface of the workpiece. These heatings are usually performed with the upper limit of the heating temperature being about 135°C.
The support sheet of this embodiment has an adhesive force (Y2) of 13,000 mN/25 mm or more, thereby suppressing peeling from the ring frame even when heated at high temperature while fixed to the ring frame. can.

In the support sheet of this embodiment, since the adhesive force (X1) is 400 mN/25 mm or less, even after the support sheet to which the work or workpiece is attached is heated at high temperature, the support sheet After a workpiece is produced from the workpiece and the adhesive layer in the support sheet is cured to form a cured support sheet, the workpiece can be normally picked up from the cured support sheet, and the pick-up property is high. The purpose of heating the support sheet at a high temperature at this time is the same as above.

In this specification, the support sheet after the adhesive layer has been cured may be referred to as a "cured support sheet" in order to distinguish it from the support sheet in which the adhesive layer has not yet been cured. .

As used herein, "normal temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature, and includes, for example, a temperature of 18 to 28°C.

In this embodiment, examples of the work include a wafer, a semiconductor device panel, and the like.

The wafers include semiconductor wafers made of elemental semiconductors such as silicon, germanium, and selenium, and compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; made of insulators such as sapphire and glass. Examples include insulator wafers.
A circuit is formed on one side of a workpiece, typically a wafer, and in this specification, the side of the workpiece on which the circuit is formed is referred to as a "circuit side." The surface of the workpiece opposite to the circuit surface is referred to as the "back surface."
The wafer is divided into chips by means such as dicing. In this specification, as in the case of a wafer, the surface of the chip on which a circuit is formed is referred to as the "circuit surface", and the surface of the chip opposite to the circuit surface is referred to as the "back surface".
It is preferable that protruding electrodes such as bumps and pillars are provided on the circuit surface of the workpiece. Preferably, the protruding electrode is made of solder.

The semiconductor device panel is handled in the manufacturing process of semiconductor devices, and a specific example thereof is a semiconductor device in which one or more electronic components are sealed with a sealing resin, and a plurality of electronic components are used. These semiconductor devices may be arranged two-dimensionally in a circular, rectangular, or other shaped region.

In this embodiment, the workpiece is obtained by processing a workpiece. For example, when the workpiece is a wafer, the workpiece can be a chip, and when the workpiece is a semiconductor wafer, the workpiece Examples of the workpiece include semiconductor chips.

As used herein, the term "energy ray" refers to electromagnetic waves or charged particle beams that have energy quanta. Examples of energy rays include ultraviolet rays, radiation, electron beams, and the like. The ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, fusion lamp, xenon lamp, black light, or LED lamp as an ultraviolet source. The electron beam can be generated by an electron beam accelerator or the like.
In this specification, "energy ray curable" means a property that hardens when irradiated with energy rays, and "non-energy ray curable" means a property that does not harden even when irradiated with energy rays. do.
As used herein, "non-curable" means a property that does not harden by any means such as heating or irradiation with energy rays.

FIG. 1 is a cross-sectional view schematically showing an example of a support sheet according to an embodiment of the present invention. Note that the figures used in the following explanation may show important parts enlarged for convenience in order to make it easier to understand the features of the present invention, and the dimensional ratio of each component may be the same as the actual one. Not necessarily.

The support sheet 1 shown here includes a base material 11 and an adhesive layer 12 provided on one surface 11a of the base material 11. The support sheet 1 further includes a release film 13 provided on the surface 12a of the adhesive layer 12 on the side opposite to the base material 11 side.
One surface 11a of the base material 11 may be, for example, a matte surface or may not be a matte surface (for example, it may be a glossy surface with a small degree of unevenness).
The adhesive layer 12 is energy ray curable.
The adhesive force (Y2) measured using the support sheet 1 is 13000 mN/25 mm or more, and the adhesive force (X1) is 400 mN/25 mm or less.

As used herein, the term "matte surface" refers to a surface that has relatively large unevenness, is rough, has relatively low gloss, and appears to have been matte-treated.

The support sheet of this embodiment is not limited to that shown in FIG. 1, and some of the configurations may be changed, deleted, or added to that shown in FIG. 1 without impairing the effects of the present invention. There may be.
For example, the support sheet 1 shown in FIG. 1 includes a release film 13, but in the support sheet of this embodiment, the release film has an arbitrary configuration, and the support sheet of this embodiment does not include a release film. You can.
For example, the support sheet 1 shown in FIG. 1 includes a base material 11, an adhesive layer 12, and a release film 13, but the support sheet of this embodiment includes a base material, an adhesive layer, It may also include a release film and other layers that do not fall under any of the above. The other layers can be arbitrarily selected depending on the purpose and are not particularly limited. However, in the support sheet of this embodiment, it is preferable that the base material and the adhesive layer are provided in direct contact with each other, and that the adhesive layer and the release film are provided in direct contact with each other.

Next, details of each layer constituting the support sheet of this embodiment will be explained.

<<Adhesive layer, adhesive composition (I)>>
The adhesive layer is in the form of a sheet or film, and is energy ray curable. The physical properties of the adhesive layer before and after curing can be adjusted.

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

In this specification, "the multiple layers may be the same or different from each other" means "all the layers may be the same or all the layers may be different", not only in the case of adhesive layers. ``Multiple layers may be the same, or only some of the layers may be the same,'' and ``the layers are different from each other'' means ``at least one of the constituent materials and thickness of each layer is different from each other.'' means.

The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 60 μm, even more preferably 5 to 30 μm, and particularly 8 to 25 μm. preferable. With the thickness of the adhesive layer within this range, when the adhesive layer is provided on the matte surface of the base material, the adhesive layer can better embed the matte surface of the base material, making it easier to process the workpiece. The above-mentioned pick-up of the material from the cured support sheet is increased.
Here, the "thickness of the adhesive layer" means the thickness of the entire adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers is the total thickness of all the layers that make up the adhesive layer. means the thickness of

In this specification, "thickness" refers to the average value of the thickness measured at five randomly selected locations on the object, unless otherwise specified, and is not limited to the case of adhesive layers. It can be obtained using a constant pressure thickness measuring device according to JIS K7130.

The adhesive layer can be formed using an adhesive composition containing components for forming the adhesive layer. For example, a pressure-sensitive adhesive layer can be formed on a target site by applying a pressure-sensitive adhesive composition to a surface on which a pressure-sensitive adhesive layer is to be formed, and drying the composition as necessary. The content ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the content ratio of the components in the adhesive layer.

In the adhesive layer, the ratio of the total content of one or more of the below-mentioned components of the adhesive layer to the total mass of the adhesive layer does not exceed 100% by mass.
Similarly, in the pressure-sensitive adhesive composition, the ratio of the total content of one or more of the below-mentioned components of the pressure-sensitive adhesive composition to the total weight of the pressure-sensitive adhesive composition does not exceed 100% by mass.

The adhesive composition may be applied by a known method, such as an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, or screen coater. , a method using various coaters such as a Meyer bar coater and a kiss coater.

Drying conditions for the adhesive composition are not particularly limited. However, when the adhesive composition contains a solvent described below, it is preferable to dry it by heating. The adhesive composition containing a solvent is preferably dried by heating at 70 to 130° C. for 10 seconds to 5 minutes, for example.

When providing a pressure-sensitive adhesive layer on a base material, for example, a pressure-sensitive adhesive composition may be coated on the base material and dried if necessary. Alternatively, for example, an adhesive layer may be formed on the release film by coating an adhesive composition on the release film and drying as necessary, and the exposed surface of this adhesive layer may be applied to the base material. The adhesive layer may be laminated on the base material by bonding it to one surface (for example, matte surface or glossy surface) of the base material. In this case, the release film may be removed either during the manufacturing process or during the use of the support sheet.

It is preferable that the adhesive layer contains an energy ray-curable compound (α). By using the adhesive layer containing the energy ray-curable compound (α), it becomes easy to adjust both the adhesive force (X1) and the adhesive force (Y2).
That is, as a preferable adhesive composition, for example, an adhesive composition (I) containing an energy ray-curable compound (α) can be mentioned.

<Energy ray curable compound (α)>
The energy ray curable compound (α) is not particularly limited as long as it has energy ray curability.
The viscosity of the energy beam curable compound (α) at 23° C. is preferably 350 mPa·s or less, for example, any of 320 mPa·s or less, 220 mPa·s or less, 120 mPa·s or less, and 60 mPa·s or less. It may be The lower the viscosity, the higher the embeddability of the adhesive layer on the matte surface of the base material.
The lower limit of the viscosity of the energy ray-curable compound (α) at 23° C. is not particularly limited. For example, the energy ray-curable compound (α) having a viscosity of 5 mPa·s or more is more easily available.
The viscosity of the energy ray curable compound (α) at 23°C is, for example, 5 to 350 mPa·s, 5 to 320 mPa·s, 5 to 220 mPa·s, 5 to 120 mPa·s, and 5 to 60 mPa·s or less. It may be either. However, these are examples of the above-mentioned viscosities.

The viscosity of the energy beam curable compound (α) at 23° C. can be measured using, for example, a single cylindrical type B (Brookfeed type) rotational viscometer.

Examples of the energy ray curable compound (α) include monomers or oligomers having an energy ray polymerizable unsaturated group and curable by irradiation with energy rays.
One molecule of the energy ray curable compound (α) has one or more of the energy ray polymerizable unsaturated groups, and may have 3 or more, but may have 1 or 2 of the energy ray polymerizable unsaturated groups. preferable.
An example of the energy beam polymerizable unsaturated group is a (meth)acryloyl group.

In this specification, "(meth)acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group." The same applies to terms similar to the (meth)acryloyl group. For example, "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid," and "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid." " is a concept that includes both "acrylate" and "methacrylate."

The energy ray-curable compound (α) is preferably a (meth)acrylic ester that may have a substituent. As the (meth)acrylic ester having a substituent, for example, a hydrocarbon group derived from alcohol (a carbonyl group in an oxycarbonyl group (-OC(=O)-) in a (meth)acrylic ester One or more carbon atoms in a hydrocarbon group bonded to an oxygen atom that does not constitute a hydrogen atom (for example, -CH ₂ -, Examples include compounds having a structure substituted with a substituent (=CH-). However, two adjacent carbon atoms shall not be substituted with a substituent.

The hydrocarbon group in the (meth)acrylic acid ester, which is the energy beam curable compound (α), may be linear, branched, or cyclic, and if cyclic, it may be monocyclic. It may be either cyclic or polycyclic. The hydrocarbon group may have both a chain structure (one or both of a linear structure and a branched structure) and a cyclic structure.

The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the aliphatic hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. There may be. In this specification, a hydrocarbon group having only an aliphatic group and no aromatic cyclic group is an aliphatic hydrocarbon group, having both an aliphatic group and an aromatic cyclic group, or A hydrocarbon group having only aromatic cyclic groups is an aromatic hydrocarbon group.

The hydrocarbon group preferably has a cyclic structure, that is, a cyclic hydrocarbon group, or a hydrocarbon group having both a chain structure and a cyclic structure.

The hydrocarbon group is preferably an alkyl group, an alkylene group, or an aralkyl group (arylalkyl group).

The substituent may be an atomic group having a structure in which a plurality of atoms are bonded together, or may be a single atom.
Preferred examples of the substituent include an oxygen atom (-O-) and the like.

When the hydrocarbon group has the substituent, the number of substituents is appropriately adjusted depending on the type of hydrocarbon group, but is usually preferably 1 to 4, and preferably 1 to 3. More preferred.

The number of carbon atoms in the hydrocarbon group is preferably 3 to 20, for example, 3 to 16, 3 to 12, and 3 to 8, or 4 to 20, 9 to 20, and 13 to 20, or 4 to 16, and 9 to 14. However, these are examples of the carbon numbers. Here, "the number of carbon atoms in the hydrocarbon group" means, when the hydrocarbon group has the above-mentioned substituent, the number of carbon atoms in the hydrocarbon group before being substituted with the substituent. For example, when a hydrocarbon group has only an oxygen atom (-O-) as a substituent, the number of carbon atoms in the hydrocarbon group refers to the number of carbon atoms in the hydrocarbon group when this oxygen atom is replaced by a group before substitution such as a methylene group (-CH ₂ -). means the number of carbon atoms in a hydrocarbon group when replaced with

The hydrocarbon group is preferably a hydrocarbon group that has a cyclic structure and may have an oxygen atom as a substituent; has both a chain structure and a cyclic structure and has an oxygen atom as a substituent. It is more preferably a hydrocarbon group which may have an atom; it is even more preferably an aliphatic hydrocarbon group or an aromatic hydrocarbon group which may have an oxygen atom as a substituent; is an aromatic hydrocarbon group having both an aliphatic group having an oxygen atom and an aromatic cyclic group having no substituent (in this specification, the energy ray-curable compound (α) in this case is referred to as is an aliphatic hydrocarbon group having both a cyclic structure without a substituent and a chain structure without a substituent (sometimes referred to as an "energy ray-curable compound (α1)"). In the specification, the energy ray curable compound (α) in this case may be referred to as the "energy ray curable compound (α2)"), or a cyclic structure having an oxygen atom as a substituent, and a substituent. (In this specification, the energy ray curable compound (α) in this case is referred to as the "energy ray curable compound (α3)"). It is even more preferable that there be By using such an energy ray-curable compound (α), when an adhesive layer is provided on the matte surface of the base material, the embeddability of the adhesive layer on the matte surface of the base material becomes higher.

An example of the energy ray curable compound (α1) is energy ray curable compound (α)-1, which will be described later in Examples.
An example of the energy ray curable compound (α2) is energy ray curable compound (α)-2 which will be described later in Examples.
An example of the energy ray curable compound (α3) is energy ray curable compound (α)-3, which will be described later in Examples.

The molecular weight of the energy ray-curable compound (α) is not particularly limited, but is preferably 500 or less. By using such an energy ray-curable compound (α), the properties of the adhesive layer become better. For example, when an adhesive layer is provided on the matte surface of the base material, the embeddability of the adhesive layer on the matte surface of the base material becomes high.

The molecular weight of the energy ray curable compound (α) is preferably 100 to 500, more preferably 200 to 400, for example, it may be any one of 200 to 310 and 200 to 280. , 250-400, and 310-400, or may be 250-310. When the molecular weight is less than or equal to the upper limit, the properties of the adhesive layer (for example, the embeddability of the matte surface of the base material by the adhesive layer) become better. When the molecular weight is at least the lower limit, the structure of the pressure-sensitive adhesive layer becomes more stable. However, these are examples of the molecular weight of the energy ray-curable compound (α).
Among the energy ray curable compounds (α1), energy ray curable compounds (α2) and energy ray curable compounds (α3), those having any of the molecular weights shown here are particularly preferred energy ray curable compounds (α) It is.

The energy ray-curable compound (α) is hydrogen bonded to one or more carbon atoms in the hydrocarbon group derived from alcohol in the (meth)acrylic ester. The (meth)acrylic acid ester may have a structure in which both atoms and substituents are substituted, the hydrocarbon group preferably has a cyclic structure, and the molecular weight is preferably 500 or less.
Such an energy ray-curable compound (α) is preferably one in which the hydrocarbon group is an alkyl group, an alkylene group, or an aralkyl group, and one in which the substituent is an oxygen atom; (α1), the energy ray curable compound (α2), or the energy ray curable compound (α3) is preferable, and those having a molecular weight within one of the more limited numerical ranges described above are preferable, and these 4 It is more preferable that one or more of the conditions be satisfied at the same time.

The adhesive layer and the adhesive composition (I) may contain only one type of energy ray-curable compound (α), or may contain two or more types, and in the case of two or more types, Their combination and ratio can be selected arbitrarily.

In the adhesive composition (I), the content ratio of the energy ray curable compound (α) to the total content of all components other than the solvent is preferably 5% by mass or more, and 10% by mass or more. , and 14% by mass or more. On the other hand, the ratio is 100% by mass or less.
The content of this content is that the content ratio of the energy ray curable compound (α) to the total mass of the adhesive layer is preferably 5% by mass or more, 10% by mass or more, and 14% by mass. % or more, and the ratio is synonymous with being 100% by mass or less.
This is based on the fact that in the process of removing the solvent from a resin composition containing a solvent to form a resin film, the amounts of components other than the solvent usually do not change. In this case, the content ratios of the components other than the solvent are the same. Therefore, hereinafter, in this specification, the content of components other than the solvent will be described only in the resin film obtained by removing the solvent from the resin composition, not only in the case of the adhesive layer.

<Energy ray curable acrylic resin (Ia)>
The adhesive layer and the adhesive composition (I) further contain an energy ray curable acrylic resin (herein also referred to as "energy ray curable acrylic resin (Ia)"), that is, It is more preferable to contain both an energy ray curable compound and an energy ray curable acrylic resin. By using the adhesive layer containing the energy ray curable compound (α) and the energy ray curable acrylic resin (Ia), it is easier to adjust both the adhesive force (X1) and the adhesive force (Y2). becomes.

Examples of the energy ray curable acrylic resin (Ia) include resins having a structure in which an unsaturated group is introduced into the side chain of a non-energy ray curable acrylic resin.

[Non-energy ray curable acrylic resin]
Examples of the non-energy ray-curable acrylic resin include an acrylic polymer having a structural unit derived from an alkyl (meth)acrylate ester and a structural unit derived from a functional group-containing monomer.

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. The alkyl group constituting the alkyl ester may be linear, branched, or cyclic, but is preferably linear or branched.

Among the (meth)acrylic acid alkyl esters, examples of those in which the alkyl group is linear or branched include methyl (meth)acrylate, ethyl (meth)acrylate, and n-(meth)acrylate. Propyl, isopropyl (meth)acrylate, n-butyl (meth)acrylate, 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, (meth) ) isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate ((meth)acrylate ) myristyl acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), Examples include nonadecyl (meth)acrylate and icosyl (meth)acrylate.

Among the (meth)acrylic acid alkyl esters, those in which the alkyl group is cyclic include, for example, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and the like.

Among the above, the (meth)acrylic acid alkyl esters are 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, dodecyl acrylate (lauryl acrylate), or methacrylic acid in that they can lower the adhesive force (X1). Dodecyl (lauryl methacrylate) is preferred.

The functional group-containing monomer may be, for example, a non-energy ray-curable acrylic monomer in which the functional group reacts with a crosslinking agent described later to become a crosslinking starting point, or a non-energy ray-curable acrylic monomer in which the functional group is in an unsaturated group-containing compound described later. Examples include those that make it possible to introduce an unsaturated group into the side chain of an acrylic polymer by reacting with a group that can be bonded (reacted) with a resin.

Examples of the functional group-containing monomer include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers.

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)acrylate. Hydroxyalkyl (meth)acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; non-(meth)acrylic unsaturated such as vinyl alcohol, allyl alcohol, etc. Examples include alcohol (unsaturated alcohol without a (meth)acryloyl skeleton).
Among these, the hydroxyl group-containing monomer is preferably hydroxyalkyl methacrylate, and 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, or 2-hydroxypropyl methacrylate is preferable from the viewpoint that the adhesive force (X1) can be lowered. More preferred is hydroxybutyl.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; fumaric acid, itaconic acid, maleic acid, and citraconic acid. Examples include ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as acids; anhydrides of the ethylenically unsaturated dicarboxylic acids; (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate; It will be done.

Examples of the epoxy group-containing monomer include glycidyl group-containing (meth)acrylic esters such as glycidyl (meth)acrylate.

The functional group-containing monomer is preferably a hydroxyl group-containing monomer.

The non-energy ray-curable acrylic resin has a structural unit derived from a (meth)acrylic acid alkyl ester and a structural unit derived from another monomer that does not fall under either of the structural units derived from the functional group-containing monomer. It's okay.

The other monomers are not particularly limited as long as they can be copolymerized with (meth)acrylic acid alkyl ester and the like.
Examples of the other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

The non-energy ray-curable acrylic resin has only one type of structural unit derived from the (meth)acrylic acid alkyl ester, the structural unit derived from the functional group-containing monomer, and the structural unit derived from the other monomer. There may be one or two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

In the non-energy beam-curable acrylic resin, the content of the structural units derived from the (meth)acrylic acid alkyl ester is preferably 65 to 99% by mass based on the total amount of the structural units.

In the non-energy ray-curable acrylic resin, the content of structural units derived from functional group-containing monomers is preferably 1 to 35% by mass based on the total amount of structural units.

In the non-energy ray-curable acrylic resin, the content of the structural units derived from the other monomers is preferably 0 to 10% by mass based on the total amount of the structural units.

The energy ray curable acrylic resin (Ia) can be obtained, for example, by reacting the functional group in the non-energy ray curable acrylic resin with an unsaturated group-containing compound having an energy ray polymerizable unsaturated group.

In addition to the energy beam polymerizable unsaturated group, the unsaturated group-containing compound reacts with a functional group in the non-energy beam curable acrylic resin to form a group capable of bonding with the non-energy beam curable acrylic resin. It is a compound that has
Examples of the energy ray polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), and a (meth)acryloyl group is preferred.
Groups capable of bonding with the functional groups in the non-energy ray-curable acrylic resin include, for example, isocyanate groups and glycidyl groups capable of bonding with hydroxyl groups or amino groups, and hydroxyl groups and amino groups capable of bonding with carboxy groups or epoxy groups. etc.

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

When obtaining the energy beam curable acrylic resin (Ia) by reacting the functional group in the non-energy beam curable acrylic resin with an unsaturated group-containing compound having an energy beam polymerizable unsaturated group, The total number of moles of the unsaturated groups in the unsaturated group-containing compound is either 0.6 times or more and 0.75 times or more relative to the total number of moles of the functional groups in the linearly curable acrylic resin. However, it is preferably 0.8 times or more, more preferably 0.85 times or more, and even more preferably 0.9 times or more. As the total number of moles of the unsaturated groups increases, the adhesive force (X1) can be lowered, and the pick-up property of the workpiece from the cured support sheet tends to be higher.
On the other hand, the total number of moles of the unsaturated groups in the unsaturated group-containing compound is preferably one or less times the total number of moles of the functional groups in the non-energy ray-curable acrylic resin.

The adhesive layer and the adhesive composition (I) may contain only one type of energy ray-curable acrylic resin (Ia), or may contain two or more types, and in the case of two or more types. , their combination and ratio can be selected arbitrarily.

When the adhesive layer and the adhesive composition (I) contain the energy ray curable acrylic resin (Ia), the content of the energy ray curable compound (α) in the adhesive layer relative to the total mass of the adhesive layer. It is preferable that the proportion of % or 10 to 35% by mass. When the ratio is equal to or higher than the lower limit, the properties of the adhesive layer (for example, the embeddability of the matte surface of the base material by the adhesive layer) become better. When the ratio is equal to or less than the upper limit value, the pick-up property of picking up the above-mentioned workpiece from the support sheet without any abnormality becomes higher.

When the pressure-sensitive adhesive layer and the pressure-sensitive adhesive composition (I) contain an energy-beam-curable acrylic resin (Ia), the content of the energy-beam-curable acrylic resin (Ia) in the pressure-sensitive adhesive layer relative to the total mass of the pressure-sensitive adhesive layer. The amount ratio is preferably 50 to 95% by mass, for example, it may be 65 to 95% by mass, and 75 to 95% by mass, or 50 to 90% by mass, and 50 to 86% by mass. It may be either % by mass or 65 to 90% by mass. When the ratio is equal to or higher than the lower limit value, the pick-up property that allows the workpiece to be picked up from the support sheet without any abnormality becomes higher. When the ratio is less than or equal to the upper limit, the properties of the adhesive layer (for example, the embeddability of the matte surface of the base material by the adhesive layer) become better.

<Other ingredients>
The adhesive layer and the adhesive composition (I) fall under both the energy ray curable compound (α) and the energy ray curable acrylic resin (Ia) within a range that does not impair the effects of the present invention. It may contain other ingredients.
Examples of the other components include a crosslinking agent (β), a photopolymerization initiator (γ), and additives.

The pressure-sensitive adhesive layer and the pressure-sensitive adhesive composition (I) may contain only one type of other components, or may contain two or more types, and when they are two or more types, a combination thereof and The ratio can be selected arbitrarily.

[Crosslinking agent (β)]
When preparing the energy beam curable acrylic resin (Ia), if any of the functional groups in the non-energy beam curable acrylic resin remain unreacted with the unsaturated group-containing compound, the energy beam curable acrylic resin (Ia) Ia) has this functional group. When such an energy ray-curable acrylic resin (Ia) is used, the adhesive layer and the adhesive composition (I) may further contain a crosslinking agent (β). In the adhesive layer and adhesive composition (I) containing the crosslinking agent (β), the energy ray-curable acrylic resins (Ia) can be crosslinked with each other.

Examples of the crosslinking agent (β) include isocyanate crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy type crosslinking agents such as ethylene glycol glycidyl ether; Crosslinking agent (crosslinking agent having a glycidyl group); Aziridine crosslinking agent (crosslinking agent having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine; Metal chelate crosslinking agent such as aluminum chelate agents (crosslinking agents having a metal chelate structure); isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton); and the like.
Among these, it is preferable that the crosslinking agent (β) is an adduct of hexamethylene diisocyanate, since it becomes easier to adjust the adhesive force (X1) to the range described below.

The adhesive layer and the adhesive composition (I) may contain only one type of crosslinking agent (β), or may contain two or more types, and in the case of two or more types, a combination thereof. and the ratio can be selected arbitrarily.

In the adhesive layer, the content of the crosslinking agent (β) is preferably 0.1 to 7 parts by mass, for example, 0.1 to 7 parts by mass, based on 100 parts by mass of the energy ray-curable acrylic resin (Ia). .1 to 5 parts by mass, and 0.1 to 3 parts by mass, or 0.5 to 7 parts by mass, 1 to 7 parts by mass, and 3 to 7 parts by mass. The amount may be either 0.5 to 5 parts by mass or 1 to 3 parts by mass. When the content of the crosslinking agent (β) is within such a range, it becomes easy to adjust both the adhesive force (X1) and the adhesive force (Y2).

[Photopolymerization initiator (γ)]
The adhesive layer and the adhesive composition (I) may further contain a photopolymerization initiator (γ). The adhesive layer and adhesive composition (I) containing the photopolymerization initiator (γ) undergo a sufficient curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator (γ) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone; 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-1-(4-(4-(2- Acetophenone compounds such as hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl Acyl phosphine oxide compounds such as phosphine oxide; Sulfide compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; Azo compounds such as azobisisobutyronitrile; Titanocene titanocene compounds such as; 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- Examples include quinone compounds such as [4-(1-methylvinyl)phenyl]propanone; 1-chloroanthraquinone and 2-chloroanthraquinone.
As the photopolymerization initiator (γ), for example, a photosensitizer such as an amine can also be used.
Among these, the photopolymerization initiator (γ) is 2-hydroxy-1-(4-(4-(2-hydroxy- Preference is given to 2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one.

The number of photopolymerization initiators (γ) contained in the adhesive layer and the adhesive composition (I) may be one, or two or more. The combination and ratio can be arbitrarily selected.

In the adhesive layer, the content of the photopolymerization initiator (γ) is determined by the content of the energy ray curable compound (α) and the energy ray curable compound (α), regardless of the presence or absence of the energy ray curable acrylic resin (Ia) in the adhesive layer. The amount is preferably 0.5 to 5 parts by weight, for example, 1 to 4 parts by weight, and 1.5 to 3.5 parts by weight, based on 100 parts by weight of the total content of the curable acrylic resin (Ia). It may be any one of the following sections.

[Additive]
Examples of the additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, colorants (pigments, dyes), sensitizers, tackifiers, and reactive agents. Known additives such as retarders and crosslinking promoters (catalysts) may be mentioned.
The reaction retarder is, for example, a substance that inhibits unintended crosslinking reactions from proceeding in the adhesive composition (I) during storage due to the action of a catalyst mixed in the adhesive composition (I). It is an ingredient that Examples of the reaction retarder include those that form a chelate complex by chelating the catalyst, and more specifically, those that form a chelate complex by chelating the catalyst. Can be mentioned.

The number of additives contained in the adhesive layer and the adhesive composition (I) may be only one, or two or more, and when there are two or more, the combination and ratio of the additives are as follows: Can be selected arbitrarily.

The content of the additive in the adhesive composition (I) is not particularly limited, and may be appropriately selected depending on the type thereof.

[solvent]
Adhesive composition (I) may contain a solvent. By containing the solvent, the adhesive composition (I) improves its suitability for coating onto the surface to be coated.

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

The pressure-sensitive adhesive composition (I) may contain only one kind of solvent, or may contain two or more kinds of solvents, and when there are two or more kinds of solvents, the combination and ratio thereof can be arbitrarily selected.

The content of the solvent in the adhesive composition (I) is not particularly limited, and may be adjusted as appropriate.

<One embodiment of adhesive layer>
As an example of a preferable adhesive layer and adhesive composition (I), an energy ray curable compound (α), an energy ray curable acrylic resin (Ia), a crosslinking agent (β) and a photopolymerization initiator (γ) are used. Examples include those containing

<Method for producing adhesive composition (I)>
The adhesive composition (I) contains each component for constituting the adhesive composition (I), such as an energy ray curable compound (α) and, if necessary, an energy ray curable acrylic resin (Ia). Obtained by blending.
The order in which each component is added when blending is not particularly limited, and two or more components may be added at the same time.
The method of mixing each component at the time of compounding is not particularly limited, and may be any known method, such as mixing by rotating a stirrer or stirring blade; mixing by using a mixer; or mixing by applying ultrasonic waves. You can select it as appropriate.
The temperature and time during addition and mixing of each component are not particularly limited as long as each component does not deteriorate, and may be adjusted as appropriate, but the temperature is preferably 15 to 30°C.

<<Base material>>
The base material is in the form of a sheet or a film, and its constituent materials include, for example, various resins.
Examples of the resin include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyethylene other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin. Polyolefin: Ethylene copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (ethylene as a monomer) polyvinyl chloride, vinyl chloride resins such as vinyl chloride copolymers (resins obtained using vinyl chloride as a monomer); polystyrene; polycycloolefin; polyethylene terephthalate, polyethylene Polyesters such as naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalene dicarboxylate, and fully aromatic polyesters in which all constituent units have aromatic cyclic groups; combinations of two or more of the above polyesters. Polymer; poly(meth)acrylic ester; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene oxide; polyphenylene sulfide; polysulfone; polyether ketone.
Examples of the resin include polymer alloys such as mixtures of the polyester and other resins. The polymer alloy of the polyester and other resin preferably has a relatively small amount of resin other than the polyester.
In addition, examples of the resin include, for example, a crosslinked resin obtained by crosslinking one or more of the resins exemplified above; modified ionomers using one or more of the resins exemplified above; Also mentioned are resins.

Among the above resins, polypropylene or polybutylene terephthalate is preferable as the resin constituting the base material, since the base material has higher heat resistance at high temperatures (approximately 135° C.) and flexibility.

The number of resins constituting the base material may be one, or two or more, and when there are two or more, the combination and ratio thereof can be arbitrarily selected.

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

In the support sheet, since the adhesive layer is energy ray-curable, the base material is preferably one that allows energy rays to pass through, and is preferably transparent.

In the base material, it is preferable that at least one surface is a matte surface, and both surfaces may be matte surfaces, one surface is a matte surface, and the other surface is a glossy surface with a small degree of unevenness. There may be.
In the support sheet, an adhesive layer may be provided on the matte surface of the base material. When both surfaces of the base material are matte surfaces, an adhesive layer may be provided on the matte surface with greater surface roughness (Ra).

The matte surface of the base material is a surface of the base material that has a roughness of a certain value or more, and has low gloss, so it can be clearly identified by its appearance. A base material having at least one matte surface is available as a commercial product, and can also be produced by a known method.

The surface roughness (Ra) of the matte surface of the base material is preferably 0.05 μm or more, and may be, for example, any of 0.1 μm or more, 0.4 μm or more, and 0.7 μm or more. When the composition of the adhesive layer is adjusted and the adhesive layer is provided on the matte surface of the base material by the surface roughness being equal to or greater than the lower limit value, the embeddability of the adhesive layer on the matte surface of the base material is high. This effect is more noticeable. Moreover, blocking of the base materials when the base materials are stacked and stored is further suppressed.
The upper limit of the surface roughness (Ra) of the matte surface of the base material is not particularly limited. For example, the surface roughness is preferably 2 μm or less in order to prevent the surface unevenness from becoming excessively large.
The surface roughness (Ra) of the matte surface of the base material may be, for example, any one of 0.05 to 2 μm, 0.1 to 2 μm, 0.4 to 2 μm, and 0.7 to 2 μm. However, these are examples of the surface roughness.

In this specification, "surface roughness (Ra)" is not limited to the matte surface of the base material, but refers to the so-called arithmetic mean roughness determined in accordance with JIS B0601:2001.

The surface roughness (Ra) of the glossy surface of the base material is preferably less than 0.05 μm, and may be, for example, 0.04 μm or less. When the surface roughness is within this range, the average light transmittance of the support sheet described below in the wavelength range of 400 to 800 nm becomes higher.
The lower limit of the surface roughness (Ra) of the glossy surface of the base material is not particularly limited. For example, the surface roughness is preferably 0.01 μm or more in terms of suppressing blocking of the base materials when the base materials are stacked and stored.
The surface roughness (Ra) of the glossy surface of the base material may be, for example, 0.01 μm or more and less than 0.05 μm, or 0.01 to 0.04 μm. However, these are examples of the surface roughness.

The surface roughness (Ra) of both sides of the base material can be adjusted by, for example, molding conditions of the base material, surface treatment conditions, etc. Examples of the surface treatment include roughening treatment such as sandblasting treatment and solvent treatment, and smoothing treatment such as polishing treatment.

The base material is subjected to corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc. in order to adjust the adhesiveness with the adhesive layer provided on it. The surface may be subjected to oxidation treatment; lipophilic treatment; hydrophilic treatment, etc. The surface of the base material may be treated with a primer.

The base material may be composed of one layer (single layer) or may be composed of two or more layers, and when composed of multiple layers, these multiple layers may be the same or different from each other. The combination of these multiple 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 heat resistance (for example, about 135° C.), flexibility, and suitability for attachment to a workpiece are further improved.
Here, the "thickness of the base material" means the thickness of the entire base material. For example, the thickness of a base material consisting of multiple layers refers to the total thickness of all the layers that make up the base material. means.

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

<<Release film>>
The release film may be a known release film.
More specifically, the release film includes, for example, one in which one or both surfaces of the base material for a release film is a release-treated surface. The release film base material is preferably a polyethylene terephthalate film.
The release-treated surface can be formed by subjecting the surface of the base material for a release film to a release treatment using a known release agent.
The thickness of the release film may be, for example, 2 to 300 μm, preferably 20 to 100 μm.

Next, the physical properties of the support sheet (adhesive layer) will be explained.

<Adhesive strength (X1)>
The adhesive force (X1) is 400 mN/25 mm or less, preferably 340 mN/25 mm or less, and may be any of 280 mN/25 mm or less, 220 mN/25 mm or less, and 180 mN/25 mm or less. . The smaller the adhesive force (X1) is, the higher the pick-up property is, allowing the workpiece to be picked up from the cured support sheet without any abnormality.
The lower limit of the adhesive force (X1) is not particularly limited. For example, an adhesive layer having an adhesive force (X1) of 30 mN/25 mm or more can be formed more easily.
The adhesive strength (X1) may be, for example, 30 to 400 mN/25 mm, 30 to 340 mN/25 mm, 30 to 280 mN/25 mm, 30 to 220 mN/25 mm, and 30 to 180 mN/25 mm or less. However, these are examples of adhesive strength (X1).

Adhesive force (X1) can be measured, for example, by the method shown below.
That is, first, a test piece with a width of 25 mm is cut out from a support sheet.
Next, this test piece (support sheet) is attached to the mirror surface of the silicon mirror wafer using the adhesive layer therein, thereby producing a silicon mirror wafer with a test piece. At this time, the pasting is preferably carried out at room temperature, at a speed of 290 to 310 mm/min, at a pressure of 0.3 MPa, using a laminating roller.
Next, the obtained silicon mirror wafer with a test piece is heated at 130° C. for 2 hours.
Next, the silicon mirror wafer with the test piece was cooled by cooling until the temperature reached 23°C, and then the silicon mirror wafer with the test piece after cooling was cooled under the conditions of an illuminance of 230 mW/cm ² and a light amount of 200 mJ/cm ² . The adhesive layer in the test piece is cured by irradiating the adhesive layer with energy rays through the base material.
Next, the test piece is peeled from the silicon mirror wafer at a peeling rate of 300 mm/min at room temperature. At this time, the test piece was peeled in its length direction so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted formed an angle of 180°. The so-called 180° peeling is performed. Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Exclude from valid values. Then, the average value of the measured values is adopted as the adhesive force (X1) (mN/25 mm).
In this embodiment, such peeling force measurements are performed on two or more test pieces (support sheets), and the average value of the obtained plurality of measured values is calculated as the adhesive force (X1). It may be adopted as

<Adhesive strength (X2)>
The supporting sheet is pasted on the mirror surface of the silicon mirror wafer using the adhesive layer, and the adhesive layer after pasting is heated at 130° C., so that the heated adhesive layer and the silicon mirror wafer are separated. When the adhesive force (X2) (herein sometimes simply referred to as "adhesive force (X2)") between the two is measured, it is preferable that the adhesive force (X2) is 13000 mN/25 mm or more. By using such a support sheet, even after heating the support sheet with the workpiece or workpiece attached to it at a high temperature, the workpiece can be easily removed by processing the workpiece or washing the workpiece with water. Peeling of the workpiece from the support sheet is suppressed even if a large force is applied to the workpiece.

The adhesive force (X2) is more preferably 14,000 mN/25 mm or more, and may be, for example, any one of 14,700 mN/25 mm or more, 15,400 mN/25 mm or more, and 16,100 mN/25 mm or more. The larger the adhesive force (X2) is, the higher the effect of suppressing the above-mentioned peeling of the workpiece from the support sheet becomes.
The upper limit of the adhesive force (X2) is not particularly limited. For example, an adhesive layer having an adhesive force (X2) of 19000 mN/25 mm or less can be formed more easily.
The adhesive force (X2) may be, for example, any one of 13000 to 19000 mN/25 mm, 14000 to 19000 mN/25 mm, 14700 to 19000 mN/25 mm, 15400 to 19000 mN/25 mm, and 16100 to 19000 mN/25 mm. However, these are examples of adhesive strength (X2).

Adhesive force (X2) can be measured, for example, by the method shown below.
That is, a silicon mirror wafer with a test piece is prepared in the same manner as when measuring the adhesive force (X1), heated at 130°C for 2 hours, and then allowed to cool until the temperature reaches 23°C.
Next, the test piece is peeled from the cooled silicon mirror wafer at a peeling rate of 300 mm/min in an environment of 23°C. At this time, the test piece was peeled in its length direction so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted formed an angle of 180°. The so-called 180° peeling is performed. Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Exclude from valid values. Then, the average value of the measured values is employed as the adhesive force (X2) (mN/25 mm).
In this embodiment, such peeling force measurements are performed on two or more test pieces (support sheets), and the average value of the obtained plurality of measured values is calculated as the adhesive force (X2). It may be adopted as

<Adhesive strength (Y1)>
The support sheet is pasted on the surface of a stainless steel (SUS) plate using the adhesive layer, the adhesive layer after pasting is heated at 130°C, the heated adhesive layer is cured with energy rays, and the adhesive layer is cured with energy rays. When measuring the adhesive force (Y1) (herein sometimes simply referred to as "adhesive force (Y1)") between the energy ray-cured material of the adhesive layer and the stainless steel plate, the It is preferable that the adhesive strength (Y1) is 300 mN/25 mm or more.
In a method for manufacturing a workpiece to be described later, a workpiece with a support sheet, which includes a workpiece and a support sheet provided on the workpiece, is fixed to a ring frame. Then, in this state, a workpiece is produced from the workpiece, and the adhesive layer in the support sheet is made into an energy ray-cured product to become a cured support sheet. That is, after the adhesive layer is cured with energy rays, the workpiece with a support sheet is transformed into a workpiece with a hardened support sheet comprising a workpiece and a hardened support sheet provided on the workpiece; a workpiece with a hardened support sheet provided on the workpiece; A workpiece with a cured support sheet, etc., which includes a cured support sheet provided on the workpiece, is obtained. In this manner, after the adhesive layer is cured with energy rays, the laminate of the workpiece or workpiece and the cured support sheet is fixed to the ring frame.
Then, by using a support sheet having an adhesive force (Y1) of 300 mN/25 mm or more, the workpiece with the support sheet is further heated while being fixed to the ring frame, and then the support sheet (adhesive layer Even if the contact portion with the ring frame is irradiated with energy rays, the laminate of the workpiece or workpiece and the cured support sheet is prevented from peeling off from the ring frame.

The adhesive force (Y1) is more preferably 400 mN/25 mm or more, and may be either 500 mN/25 mm or more, or 600 mN/25 mm or more, for example. The larger the adhesive force (Y1) is, the higher the effect of suppressing the peeling of the laminate of the above-mentioned workpiece or workpiece and the cured support sheet from the ring frame becomes.
The upper limit of the adhesive force (Y1) is not particularly limited. For example, an adhesive layer having an adhesive force (Y1) of 2000 mN/25 mm or less can be formed more easily.
The adhesive force (Y1) may be, for example, any one of 300 to 2000 mN/25 mm, 400 to 2000 mN/25 mm, 500 to 2000 mN/25 mm, and 600 to 2000 mN/25 mm. However, these are examples of adhesive strength (Y1).

Adhesive force (Y1) can be measured, for example, by the method shown below.
That is, first, a test piece with a width of 25 mm is cut out from a support sheet.
Next, this test piece (support sheet) is attached to one side of a 1000 μm thick SUS plate using the adhesive layer therein, thereby producing a SUS plate with a test piece. At this time, the pasting is preferably carried out at room temperature, at a speed of 290 to 310 mm/min, at a pressure of 0.3 MPa, using a laminating roller.
Next, the obtained SUS plate with the test piece is heated at 130° C. for 2 hours.
Next, the SUS plate with the test piece was allowed to cool until the temperature reached 23°C, and then the adhesive in the SUS plate with the test piece after cooling was cooled under the conditions of an illuminance of 230 mW/cm ² and a light amount of 200 mJ/cm ² . The adhesive layer in the test piece is cured by irradiating the layer with energy rays through the base material.
Next, the test piece is peeled from the SUS plate at a peeling speed of 300 mm/min at room temperature. At this time, the test piece is peeled off in its length direction so that the surface of the SUS plate to which the test piece was pasted and the surface of the test piece to which the SUS board was pasted form an angle of 180°. So-called 180° peeling is performed. Then, the load (peel force) during this 180° peeling was measured, and assuming that the measurement length was 50 mm, the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Exclude from valid values. Then, the average value of the measured values is employed as the adhesive force (Y1) (mN/25 mm).
In the present embodiment, such peeling force measurements are performed on two or more test pieces (support sheets), and the average value of the obtained plurality of measured values is calculated as the adhesive force (Y1). It may be adopted as

<Adhesive strength (Y2)>
The support sheet is attached to the surface of a stainless steel (SUS) plate by the adhesive layer, the adhesive layer after attachment is heated at 130 ° C., and the adhesive layer after heating and the stainless steel plate are bonded together. When the adhesive force (Y2) between the two is measured, the adhesive force (Y2) is 13000 mN/25 mm or more. By using such a support sheet, in the method for manufacturing a workpiece to be described later, a workpiece with a support sheet, or a workpiece with a support sheet provided with a workpiece and a support sheet provided on the workpiece. Even if the workpiece is further heated while being fixed to the ring frame, peeling of the workpiece with the support sheet or the workpiece with the support sheet from the ring frame is suppressed.

The adhesive force (Y2) is preferably 14,000 mN/25 mm or more, and may be, for example, any one of 15,000 mN/25 mm or more, 16,000 mN/25 mm or more, and 17,000 mN/25 mm or more. The larger the adhesive force (Y2) is, the higher the effect of suppressing the peeling of the above-mentioned workpiece with a support sheet or the processed workpiece with a support sheet from the ring frame becomes.
The upper limit of the adhesive force (Y2) is not particularly limited. For example, an adhesive layer having an adhesive force (Y2) of 20,000 mN/25 mm or less can be formed more easily.
The adhesive force (Y2) may be, for example, any one of 13000 to 20000 mN/25 mm, 14000 to 20000 mN/25 mm, 15000 to 20000 mN/25 mm, 16000 to 20000 mN/25 mm, and 17000 to 20000 mN/25 mm. However, these are examples of adhesive strength (Y2).

Adhesive force (Y2) can be measured, for example, by the method shown below.
That is, a SUS plate with a test piece is prepared in the same manner as when measuring the adhesive force (Y1), heated at 130°C for 2 hours, and then allowed to cool until the temperature reaches 23°C.
Next, the test piece is peeled from the cooled SUS plate at a peeling rate of 300 mm/min in an environment of 23°C. At this time, the test piece is peeled off in its length direction so that the surface of the SUS plate to which the test piece was pasted and the surface of the test piece to which the SUS board was pasted form an angle of 180°. So-called 180° peeling is performed. Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Exclude from valid values. Then, the average value of the measured values is adopted as the adhesive force (Y2) (mN/25 mm).
In the present embodiment, such peeling force measurements are performed on two or more test pieces (support sheets), and the average value of the obtained plurality of measured values is calculated as the adhesive force (Y2). It may be adopted as

<Adhesive strength (X0)>
The support sheet was attached to the mirror surface of the silicon mirror wafer using the adhesive layer, and the silicon mirror wafer with the support sheet was stored for 30 minutes at a temperature of 23° C., and the adhesive layer was attached to the silicon mirror wafer. When the adhesive force (X0) (herein sometimes simply referred to as "adhesive force (X0)") between and the silicon mirror wafer is measured, the adhesive force (X0) is 2000 mN. /25 mm or more is preferable. By using such a support sheet, with the workpiece or workpiece attached to the support sheet, processing that places a large load on the workpiece (for example, high-speed dicing of semiconductor wafers) or processing that reduces the load on the workpiece can be performed. Even if a larger force is applied to the workpiece, such as during large water washing (for example, washing semiconductor chips with high water pressure after dicing), separation of the workpiece from the support sheet is suppressed.

The adhesive force (X0) is more preferably 2500 mN/25 mm or more, and may be, for example, any of 3000 mN/25 mm or more, 3500 mN/25 mm or more, and 4000 mN/25 mm or more. The larger the adhesive force (X0) is, the higher the effect of suppressing the above-mentioned peeling of the workpiece from the support sheet becomes.
The upper limit of the adhesive force (X0) is not particularly limited. For example, in terms of coexistence between the adhesive force (X0) and other physical properties of the adhesive layer, the adhesive force (X0) is preferably 6000 mN/25 mm or less.
The adhesive force (X0) may be, for example, any one of 2000 to 6000 mN/25 mm, 2500 to 6000 mN/25 mm, 3000 to 6000 mN/25 mm, 3500 to 6000 mN/25 mm, and 4000 to 6000 mN/25 mm. However, these are examples of adhesive strength (X0).

Adhesive force (X0) can be measured, for example, by the method shown below.
That is, first, a test piece with a width of 25 mm is cut out from a support sheet.
Next, this test piece (support sheet) is attached to the mirror surface of the silicon mirror wafer using the adhesive layer therein, thereby producing a silicon mirror wafer with a test piece. At this time, the pasting is preferably carried out at room temperature, at a speed of 290 to 310 mm/min, at a pressure of 0.3 MPa, using a laminating roller.
Next, this silicon mirror wafer with a test piece is stored for 30 minutes at a temperature of 23°C.
Next, the test piece is peeled from the silicon mirror wafer at a peeling rate of 300 mm/min at room temperature. At this time, the test piece was peeled in its length direction so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted formed an angle of 180°. The so-called 180° peeling is performed. Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Exclude from valid values. Then, the average value of the measured values is employed as the adhesive force (X0) (mN/25 mm).
In this embodiment, such peeling force measurements are performed on two or more test pieces (support sheets), and the average value of the obtained plurality of measured values is calculated as the adhesive force (X0). It may be adopted as

<How to adjust the adhesive strength of the adhesive layer>
Various adhesive forces of the above-mentioned adhesive layer, that is, adhesive force (X1) between the energy ray cured product of the adhesive layer after heating and the silicon mirror wafer; the adhesive layer after heating and the silicon mirror wafer Adhesive force between (X2); Adhesive force between the energy ray-cured adhesive layer after heating and the SUS plate (Y1); Adhesive force between the adhesive layer after heating and the SUS plate Adhesive force (Y2) between the adhesive layer and the silicon mirror wafer (X0) can be adjusted by adjusting the type and content of the components contained in the adhesive layer.

For example, the adhesive force (X1) can be lowered by containing in the adhesive layer an energy ray-curable acrylic resin (Ia) having a structural unit derived from a functional group-containing monomer having a methacrylic group.
For example, the adhesive force (X1) can be lowered by including an energy ray-curable acrylic resin (Ia) having a relatively high glass transition temperature in the adhesive layer.
For example, a functional group (e.g., hydroxyl group) in the acrylic polymer is reacted with a group capable of bonding with the functional group in the unsaturated group-containing compound (e.g., an isocyanate group in (meth)acryloyloxyethyl isocyanate). When the total number of moles of groups capable of bonding with the functional groups in the unsaturated group-containing compound is increased by a relatively large amount (for example, 0.0000000000000 The adhesive strength (X1) can be lowered by preparing an energy ray curable acrylic resin (Ia) with an energy ray curable acrylic resin (Ia) having a temperature of 75 times or more) and including such an energy ray curable acrylic resin (Ia) in the adhesive layer.

For example, by containing the energy ray curable compound (α) in the adhesive layer, the adhesive strength (X2) can be made higher than when the energy ray curable compound (α) is not contained. Adhesive force (X2) can be further increased by adjusting the type of (α).
For example, a functional group (e.g., hydroxyl group) in the acrylic polymer is reacted with a group capable of bonding with the functional group in the unsaturated group-containing compound (e.g., an isocyanate group in (meth)acryloyloxyethyl isocyanate). When using the energy ray-curable acrylic resin (Ia) obtained by The adhesive force (X2) can be increased by containing the energy ray-curable acrylic resin (Ia) in the adhesive layer.
For example, the adhesive strength (X2) can be increased by reducing the content of the crosslinking agent (β) in the adhesive layer.

For example, the adhesive force (Y1) can be increased by including an energy ray-curable acrylic resin (Ia) having a structural unit derived from a functional group-containing monomer having a methacrylic group in the adhesive layer.
For example, the adhesive force (Y1) can be increased by incorporating a (meth)acrylic acid ester having an oxygen atom (-O-) as the substituent in the adhesive layer as the energy ray-curable compound (α). .
For example, a functional group (e.g., hydroxyl group) in the acrylic polymer is reacted with a group capable of bonding with the functional group in the unsaturated group-containing compound (e.g., an isocyanate group in (meth)acryloyloxyethyl isocyanate). When using the energy ray-curable acrylic resin (Ia) obtained by The adhesive force (Y1) can be increased by containing the energy ray-curable acrylic resin (Ia) in the adhesive layer.
For example, the adhesive force (Y1) can be increased by reducing the content of the crosslinking agent (β) in the adhesive layer.

For example, by containing the energy ray curable compound (α) in the adhesive layer, the adhesive force (Y2) can be made higher than when the energy ray curable compound (α) is not contained. Adhesive force (Y2) can be further increased by adjusting the type of (α).
For example, a functional group (e.g., hydroxyl group) in the acrylic polymer is reacted with a group capable of bonding with the functional group in the unsaturated group-containing compound (e.g., an isocyanate group in (meth)acryloyloxyethyl isocyanate). When using the energy ray-curable acrylic resin (Ia) obtained by The adhesive strength (Y2) can be increased by containing the energy ray-curable acrylic resin (Ia) in the adhesive layer.
For example, the adhesive force (Y2) can be increased by reducing the content of the crosslinking agent (β) in the adhesive layer.

For example, a functional group (e.g., hydroxyl group) in the acrylic polymer is reacted with a group capable of bonding with the functional group in the unsaturated group-containing compound (e.g., an isocyanate group in (meth)acryloyloxyethyl isocyanate). When using the energy ray-curable acrylic resin (Ia) obtained by Adhesive strength (X0) can be increased by containing energy ray-curable acrylic resin (Ia) in the adhesive layer.
For example, the adhesive strength (X0) can be increased by reducing the content of the crosslinking agent (β) in the adhesive layer.

For example, in an adhesive layer containing an energy beam-curable compound (α), an energy beam-curable acrylic resin (Ia), and a crosslinking agent (β), the crosslinking agent (β) is a chain structure having no ring structure. By using a material having a ring structure, the adhesive force (Y2) tends to be higher and the adhesive force (X1) can be lower than when using a material having a ring structure.
For example, in an adhesive layer containing an energy beam-curable compound (α), an energy beam-curable acrylic resin (Ia), and a crosslinking agent (β), the crosslinking agent (β) may be a trimethylolpropane adduct of diisocyanate, etc. By using a material having a urethane bond, the adhesive force (Y2) tends to be higher and the adhesive force (X1) tends to be lower than when using a material having no urethane bond.
For example, in an adhesive layer containing an energy ray curable compound (α), an energy ray curable acrylic resin (Ia), and a crosslinking agent (β), the content of the energy ray curable compound (α) should be reduced. Therefore, the adhesive force (X1) can be lowered than when increasing the number.

<Average value of light transmittance (400 to 800 nm) of support sheet>
The average light transmittance (400 to 800 nm) of the support sheet is preferably 80% or more, and may be, for example, 82% or more or 84% or more. When the average value of the light transmittance (400 to 800 nm) is greater than or equal to the lower limit value, cracks and chips in the workpiece can be seen through the support sheet while the workpiece is being held on the support sheet. When inspecting for damage (for example, chipping), the inspection accuracy becomes higher.
The upper limit of the average value of the light transmittance (400 to 800 nm) is not particularly limited. For example, a support sheet in which the average value of the light transmittance (400 to 800 nm) is 95% or less can be manufactured more easily.
The average value of the light transmittance (400 to 800 nm) may be, for example, any one of 80 to 95%, 82 to 95%, and 84 to 95%. However, these are examples of average values of the light transmittance (400 to 800 nm).
However, in this specification, unless otherwise specified, the light transmittance of the support sheet is not limited to the light transmittance in the wavelength range of 400 to 800 nm, and refers to the light transmittance of the support sheet without a release film. Means light transmittance.

The average value of the light transmittance (400 to 800 nm) of the support sheet can be calculated, for example, by the method shown below.
That is, the light transmittance is measured by irradiating the support sheet with light from the outside on the base material side and receiving the light directly without using an integrating sphere, and the light transmittance is measured every 1 nm in the wavelength range of 400 to 800 nm. , the light transmittance value T _n (where n is an integer from 400 to 800) is measured when the wavelength is n (nm). Then, all T _{n values} where n is 400 to 800 are added up to calculate the total value T _400-800 . The average light transmittance (400-800 nm) of the support sheet is determined by dividing the obtained T _400-800 by the number of measurements of T _n (i.e., 800-400+1=401) (T _400-800 /401). Values can be calculated.

The average value of the light transmittance (400 to 800 nm) of the support sheet can be determined by adjusting, for example, the type and content of the components contained in the base material, the roughness of both sides of the base material (for example, surface roughness (Ra)), etc. You can adjust it by doing this. Further, the average value of the light transmittance (400 to 800 nm) of the support sheet can also be adjusted by adjusting the type and content of the components contained in the adhesive layer.

<Example of support sheet>
In addition to adhesive force (Y2) and adhesive force (X1), the support sheet further has one or two types selected from the group consisting of adhesive force (X2), adhesive force (Y1), and adhesive force (X0). It is preferred that the species or more be in any of the above numerical ranges.
That is, as an example of a preferable support sheet, for example, the following conditions (1-1):
(1-1) The adhesive force (Y2) between the adhesive layer and the SUS plate after heating is 13000 mN/25 mm or more.
And the following condition (1-2):
(1-2) The adhesive force (X1) between the energy ray-cured adhesive layer after heating and the silicon mirror wafer is 400 mN/25 mm or less.
, and the following conditions (1-3) to (1-5):
(1-3) The adhesive force (X2) between the adhesive layer after heating and the silicon mirror wafer is 13000 mN/25 mm or more.
(1-4) The adhesive force (Y1) between the energy ray-cured adhesive layer and the SUS plate after heating is 300 mN/25 mm or more.
(1-5) The adhesive force (X0) between the adhesive layer and the silicon mirror wafer is 2000 mN/25 mm or more.
A support sheet that satisfies one or more types selected from the group consisting of:
An example of a more preferable support sheet includes a support sheet that satisfies all of the conditions (1-1) to (1-5) above.
In the support sheet illustrated here, one or two selected from the group consisting of adhesive force (X1), adhesive force (X2), adhesive force (Y1), adhesive force (Y2), and adhesive force (X0). It is particularly preferred that the species or more are further limited to any of the numerical ranges set out above.

◇Method for manufacturing support sheet The support sheet is manufactured by laminating the above-mentioned layers constituting it so that they have a corresponding positional relationship, and adjusting the shape of some or all of the layers as necessary. can. The method for forming each layer is as described above.
For example, a support sheet can be manufactured by coating the above-mentioned adhesive composition (I) on one side (for example, a matte side or a glossy side) of a base material and drying it as necessary.

A pressure-sensitive adhesive layer is formed on the release film by coating the pressure-sensitive adhesive composition (I) on one side of the release film and drying it if necessary, and the exposed surface of the pressure-sensitive adhesive layer is A support sheet can also be produced by bonding the support sheet to one surface (for example, a matte surface or a glossy surface) of a base material. At this time, the adhesive composition (I) is preferably applied to the release-treated surface of the release film.

The pressure applied when bonding the adhesive layer to the base material in this way (sticking pressure) is preferably 0.2 to 0.6 MPa. When the pressure is equal to or higher than the lower limit value, the adhesion between the adhesive layer and the base material can be sufficiently increased, and the composition of the adhesive layer can be adjusted to form an adhesive layer on the matte surface of the base material. In the case of providing the matte surface of the base material, the embeddability of the adhesive layer on the matte surface of the base material can be further improved. Excessive pressurization can be avoided because the pressure is below the upper limit value.
Such bonding of the adhesive layer and the base material is preferably carried out at a temperature of, for example, 15° C. or higher, and may be carried out at room temperature.

The support sheet provided with the other layer can be prepared by, for example, applying a composition for forming the other layer to an appropriate location on the base material or the adhesive layer, and drying it as necessary. It can be manufactured by forming other layers and laminating further necessary layers as needed. In addition, by laminating other film-like layers at appropriate locations on the base material or adhesive layer, other layers can be provided, and if necessary, further layers can be laminated. can.

◇Composite sheet for forming a protective film The support sheet can constitute a composite sheet for forming a protective film by laminating it with a protective film forming film. That is, the protective film-forming composite sheet includes the support sheet and a protective film-forming film provided on the surface of the adhesive layer in the support sheet opposite to the base material side. There is. More specifically, the composite sheet for forming a protective film includes a base material, an adhesive layer provided on one side of the base material, and a side of the adhesive layer opposite to the base material side. A protective film forming film provided on the surface. The protective film-forming composite sheet may further include a release film provided on the surface of the protective film-forming film opposite to the pressure-sensitive adhesive layer side.

<<Protective film forming film>>
The protective film forming film is a film for forming a protective film on any part of the workpiece. By using the composite sheet for forming a protective film, it is possible to manufacture a workpiece with a protective film, which includes a workpiece and a protective film provided at any location on the workpiece. For example, when the workpiece is a wafer, by using the composite sheet for forming a protective film, a chip with a protective film including a chip and a protective film provided on the back surface of the chip can be manufactured.

The protective film forming film may be curable or non-curable. That is, the protective film forming film may function as a protective film when cured, or may function as a protective film in an uncured state.
The curable protective film-forming film may be either thermosetting or energy ray curable, or may have both thermosetting and energy ray curable properties.

The protective film forming film may be composed of one layer (single layer) or may be composed of two or more layers. When the protective film forming film consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

Examples of the thermosetting protective film-forming film include those containing a polymer component (A) and a thermosetting component (B).
Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins.
Examples of the thermosetting component (B) include epoxy thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins.
In this specification, the thermosetting polyimide resin is a general term for a polyimide precursor and a thermosetting polyimide that form a polyimide resin by thermosetting.
The epoxy thermosetting resin includes an epoxy resin (B1) and a thermosetting agent (B2).

In addition to these components, the thermosetting protective film forming film further contains a curing accelerator (C), a filler (D), a coupling agent (E), a crosslinking agent (F), and an energy ray curable resin (G). ), a photopolymerization initiator (H), a colorant (I), and a general-purpose additive (J).

Examples of the energy ray curable protective film forming film include those containing the energy ray curable component (a).
Examples of the energy ray curable component (a) include a polymer (a1) having an energy ray curable group and a weight average molecular weight of 80,000 to 2,000,000, and a compound having an energy ray curable group and a molecular weight of 100 to 80,000. (a2) etc. are mentioned.

It is preferable that the energy ray curable protective film forming film further contains a polymer (b) having no energy ray curable group in addition to the energy ray curable component (a).
Examples of the polymer (b) without energy ray-curable groups include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins.

In addition to the energy ray curable component (a) and the polymer having no energy ray curable group (b), the energy ray curable protective film forming film further contains a colorant, a thermosetting component, a thermosetting agent, and a filler. The composition may contain one or more selected from the group consisting of additives, coupling agents, crosslinking agents, photopolymerization initiators, and general-purpose additives.

Examples of the non-curable protective film-forming film include those containing a polymer component.
Examples of the polymer component include those similar to non-curable resins, such as the polymer component (A) listed as a component of the above-mentioned thermosetting protective film-forming film.

In addition to the polymer component, the non-curable protective film-forming film further contains one or more selected from the group consisting of a colorant, a filler, a coupling agent, a crosslinking agent, and a general-purpose additive. You can leave it there.

The thickness of the protective film-forming film is preferably 1 to 100 μm. When the thickness of the protective film-forming film is equal to or greater than the lower limit, a protective film with higher protective ability can be formed. By setting the thickness of the protective film-forming film to be less than or equal to the upper limit value, it is possible to avoid excessive thickness of the protective film.
Here, the "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film. For example, the thickness of a protective film-forming film consisting of multiple layers refers to all means the total thickness of the layers.

The protective film-forming film is made of a protective film-forming composition containing its constituent materials (thermosetting protective film-forming composition for forming a thermosetting protective film-forming film, energy ray-curable protective film-forming film). It can be formed using an energy ray-curable protective film-forming composition for forming a protective film and a non-curable protective film-forming composition for forming a non-curable protective film. For example, a protective film-forming film can be formed by applying a protective film-forming composition to the surface to be formed, and drying as necessary. The content ratio of components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the content ratio of the components in the protective film-forming film.

◇Method for manufacturing a composite sheet for forming a protective film The composite sheet for forming a protective film is produced by laminating the above-mentioned layers constituting it in a corresponding positional relationship, and, if necessary, removing some or all of the layers. It can be manufactured by adjusting the shape. The method for forming each layer is as described above.
For example, a protective film-forming film is formed on the release film by coating a protective film-forming composition on one side of the release film and drying it as necessary. A composite sheet for forming a protective film is manufactured by bonding the exposed surface (the surface opposite to the release film side) with the exposed surface (the surface opposite to the base material side) of the adhesive layer in the support sheet. can. The composition for forming a protective film is preferably applied to the release-treated surface of the release film.

◇Manufacturing method of workpiece (how to use support sheet)
The support sheet can be used for manufacturing workpieces.
That is, in the method for manufacturing a workpiece according to an embodiment of the present invention, the pressure-sensitive adhesive layer in the support sheet is attached to the workpiece and the ring frame. a support sheet; and a heating step of heating the adhesive layer in the support sheet fixed to the ring frame after the pasting step. , after the attaching step, a processing step of producing the workpiece by processing the workpiece in the workpiece with the support sheet fixed to the ring frame; and after the heating step and the processing step, the ring The method includes a curing step of curing the adhesive layer attached to the frame with energy rays, and a pickup step of separating and picking up the workpiece from the cured product of the adhesive layer after the curing step.

When the workpiece is a semiconductor wafer, a method for manufacturing a workpiece, that is, a method for manufacturing a semiconductor chip, includes attaching the adhesive layer in the support sheet to the semiconductor wafer and a ring frame. , the support sheet provided on the semiconductor wafer, and a pasting step of fixing the semiconductor wafer with the support sheet to the ring frame, and after the pasting step, the support sheet provided on the semiconductor wafer is After the heating step of heating the adhesive layer and the pasting step, a processing step of manufacturing the semiconductor chip by dividing the semiconductor wafer in the semiconductor wafer with the support sheet fixed to the ring frame; After the heating step and the processing step, there is a curing step of curing the adhesive layer attached to the ring frame with energy rays, and after the curing step, the semiconductor chip is separated from the cured product of the adhesive layer and picked up. A manufacturing method including a pick-up step is mentioned.

After the pasting step, the order in which the heating step and the processing step are performed can be arbitrarily selected depending on the purpose. For example, the heating step may be performed before the processing step, or the processing step may be performed before the heating step. You may perform the process. For example, in the manufacturing method described above, a heating step can be performed in order to remove foreign substances such as low molecular weight resin components adhering to the surface of the workpiece by volatilization. The heating step in this case can be performed either before or after the processing step. In addition, in the above manufacturing method, fine foreign matter generated during processing such as dicing of the workpiece and attached to the surface of the workpiece is washed with water and removed, and then the workpiece is dried. , a heating step can be performed. The heating step in this case is performed after the processing step. In the manufacturing method, the heating step for removing these foreign substances and the heating step for drying may be performed together, or these heating steps may be performed at once.

<<An example of a method for manufacturing a workpiece>>
FIG. 2 is a cross-sectional view schematically illustrating an example of the manufacturing method when the workpiece is a semiconductor wafer. Here, a manufacturing method using the support sheet 1 shown in FIG. 1 will be described.

<Application process>
In the pasting step, the adhesive layer 12 in the support sheet 1 is pasted on the semiconductor wafer 9 (more specifically, the back surface 9b of the semiconductor wafer 9) that is the workpiece and the ring frame 8. As shown in FIG. 2A, a semiconductor wafer 109 with a support sheet, which includes a semiconductor wafer 9 and a support sheet 1 provided on the back surface 9b of the semiconductor wafer 9, is fixed to the ring frame 8. The semiconductor wafer 109 with a support sheet is the workpiece with a support sheet.
The support sheet 1 is used after the release film 13 is removed. A surface 12a of the adhesive layer 12 opposite to the base material 11 side is the same as one surface 1a of the support sheet 1 (the surface on the adhesive layer 12 side).
In FIG. 2, illustrations of bumps and the like on the circuit surface 9a of the semiconductor wafer 9 are omitted.

In the pasting process, a region of the adhesive layer 12 near the center in the width direction is pasted to the semiconductor wafer 9, and a region surrounding the pasted region to the semiconductor wafer 9 is pasted to the ring frame 8.

The support sheet 1 (adhesive layer 12) can be attached to the semiconductor wafer 9 and the ring frame 8 at room temperature.
The speed at which the support sheet 1 (adhesive layer 12) is applied to the semiconductor wafer 9 and the ring frame 8 is not particularly limited, but is preferably 200 to 400 mm/min.

<Heating process>
After the pasting process, in the heating process, the adhesive layer 12 in the support sheet 1 fixed to the ring frame 8 is heated, as shown in FIG. 2(b). In this case, the heating of the adhesive layer 12 is accompanied by the heating of the entire semiconductor wafer 109 with a support sheet, and this heating causes, for example, the adhesive layer 12 attached to the surface of the semiconductor wafer 9 (for example, the circuit surface 9a) to be heated. Foreign substances such as molecular weight resin components can be removed by volatilization.

The temperature at which the adhesive layer 12 (ie, the adhesive layer 12 in the semiconductor wafer 109 with a support sheet) is heated (heating temperature) is preferably 100 to 135°C. When the heating temperature is equal to or higher than the lower limit value, the effect of heating can be sufficiently obtained. By keeping the heating temperature at or below the upper limit value, excessive heating can be avoided, and, for example, deterioration of the semiconductor wafer 109 with a support sheet can be suppressed.

In the support sheet 1, the adhesive force (Y2) is 13000 mN/25 mm or more, so that even if the semiconductor wafer 109 with the support sheet is heated while being fixed to the ring frame 8 in the heating step, the adhesive force (Y2) is not less than 13000 mN/25 mm. Separation of the semiconductor wafer 109 from the ring frame 8 is suppressed.

<Processing process>
After the pasting step and heating step, in the processing step, as shown in FIG. 2(c), the semiconductor wafer 9 in the heated support sheet-attached semiconductor wafer 109 fixed to the ring frame 8 is divided. In this way, a semiconductor chip 90 as a workpiece is manufactured. Through the processing process, a semiconductor chip group 901 with a support sheet is obtained, in which a plurality of semiconductor chips 90 are aligned and held on one support sheet 1.

Reference numeral 90a indicates a circuit surface of the semiconductor chip 90 corresponding to the circuit surface 9a of the semiconductor wafer 9.
Reference numeral 90b indicates the back surface of the semiconductor chip 90, which corresponds to the back surface 9b of the semiconductor wafer 9.

The semiconductor wafer 9 can be divided by a known method. For example, the semiconductor wafer 9 can be divided by dicing such as blade dicing using a blade, laser dicing using laser irradiation, or water dicing using spraying water containing an abrasive.
Further, as the semiconductor wafer 9, a modified layer is formed by stealth dicing (registered trademark) and is not divided, and the semiconductor wafer 9 is placed in a direction parallel to the circuit surface 9a or the back surface 9b. The semiconductor wafer 9 can also be divided by expanding.

Stealth dicing (registered trademark) is a method as follows. That is, first, a location to be divided is set inside the semiconductor wafer, and a modified layer is formed inside the semiconductor wafer by irradiating laser light with this location as a focal point. . Unlike other parts of the semiconductor wafer, the modified layer of the semiconductor wafer is altered by the laser light irradiation, and its strength is weakened. Therefore, when force is applied to the semiconductor wafer, cracks extending in the direction of both surfaces of the semiconductor wafer are generated in the modified layer inside the semiconductor wafer, which becomes a starting point for division (cutting) of the semiconductor wafer. Next, force is applied to the semiconductor wafer to divide the semiconductor wafer at the modified layer portions, thereby producing semiconductor chips.

In the support sheet 1, when the adhesive force (X2) is 13000 mN/25 mm or more, the support sheet 1 with the semiconductor wafer 9 attached in the heating step (in other words, the semiconductor wafer 109 with the support sheet) Even after heating at a high temperature with an upper limit of about 135°C, even if a large force is applied to the semiconductor chip 90 during the processing process, such as by dividing the semiconductor wafer 9 or washing the semiconductor chip 90 with water. , peeling of the semiconductor chip 90 from the support sheet 1 (adhesive layer 12) is suppressed.

In the support sheet 1, when the adhesive force (X0) is 2000 mN/25 mm or more, the semiconductor wafer 9 may be divided into small-sized semiconductor chips 90 at high speed in the processing process, or the In addition, by washing a small-sized semiconductor chip 90 with a lot of cutting debris attached with water with high water pressure, even if a larger force is applied to the semiconductor chip 90, the support sheet 1 (adhesive layer 12 ) is suppressed from peeling off.

<Curing process>
After the heating step and processing step, in the curing step, the adhesive layer 12 attached to the ring frame 8 is cured with energy rays, as shown in FIG. 2(d). Through the curing process, a semiconductor chip group 901' with a cured support sheet is obtained, in which a plurality of semiconductor chips 90 are aligned and held on one cured support sheet 1'.
The support sheet 1 becomes a cured support sheet 1' when the adhesive layer 12 is cured with energy rays to become an energy ray cured product 12'.
The semiconductor chip group 901' with a cured support sheet is a laminate of a workpiece and a cured support sheet (in other words, a workpiece with a cured support sheet) as described above, and has an adhesive layer. It is the same as the semiconductor chip group 901 with support sheet except that 12 is the energy ray cured product 12'.

When curing the adhesive layer 12 with energy rays (when irradiating the adhesive layer 12 with energy rays), the illuminance of the energy rays is preferably 60 to 320 mW/cm ² , and the amount of energy rays is 100 mW/cm 2 . It is preferably 1000 mJ/cm ² .
The energy rays are preferably applied to the adhesive layer 12 from outside the support sheet 1 through the base material 11 (via the base material 11).

In the support sheet 1, when the adhesive force (Y1) is 300 mN/25 mm or more, the semiconductor wafer 109 with the support sheet is heated while being fixed to the ring frame 8 in the heating step, and then the curing step is performed. In this case, even if the contact portion of the support sheet 1 (adhesive layer 12) with the ring frame 8 is irradiated with energy rays, peeling of the semiconductor chip group 901' with a cured support sheet from the ring frame 8 is suppressed. Ru.

<Pickup process>
After the curing step, in the pick-up step, as shown in FIG. 2(e), the semiconductor chip 90 is separated from the energy ray cured product 12' of the adhesive layer in the cured support sheet 1' and picked up. Thereby, the target semiconductor chip 90 can be taken out from the group of semiconductor chips 901' with a cured support sheet. Here, the direction of the pickup is indicated by an arrow P.

When picking up the semiconductor chip 90, peeling occurs between the back surface 90b of the semiconductor chip 90 and the surface 12a' of the energy ray cured product 12' of the adhesive layer on the opposite side to the base material 11 side. At this time, since the adhesive force between the energy ray cured product 12' of the adhesive layer and the semiconductor chip 90 is smaller than the adhesive force between the adhesive layer 12 and the semiconductor chip 90, the semiconductor chip 90 is It is easily peeled off from the energy ray cured material 12' of the layer and can be easily picked up.
A surface 12a' of the energy ray cured material 12' of the adhesive layer on the side opposite to the base material 11 corresponds to a surface 12a of the adhesive layer 12 on the opposite side to the base material 11, and the hardened support This is the same as one surface 1a' of the sheet 1' (the surface of the adhesive layer on the energy ray cured product 12' side).

The semiconductor chip 90 can be picked up by a known method. For example, as the separating means 7 for separating the semiconductor chip 90 from the cured support sheet 1' (the adhesive layer cured with energy rays 12'), a vacuum collet or the like may be used.

In the support sheet 1, the adhesive force (X1) is 400 mN/25 mm or less, so that the support sheet 1 with the semiconductor wafer 9 attached thereto (in other words, the semiconductor wafer 109 with the support sheet) can be used in the heating step. Even after heating at a high temperature with an upper limit of about 135° C., the semiconductor chip 90 is normally picked up from the cured support sheet 1' after the semiconductor chip 90 is fabricated from the semiconductor wafer 9 on the support sheet 1. It has a high pick-up performance.

<Other processes>
The manufacturing method may include other steps that do not correspond to any of the pasting step, heating step, processing step, curing step, and pickup step.
The type of the other steps, the number of the other steps, and the timing of performing the other steps can all be arbitrarily selected depending on the purpose, and are not particularly limited.

<<Other examples of methods for manufacturing workpieces>>
Up to this point, the method for manufacturing a workpiece has been described in which the pasting process, heating process, processing process, curing process, and pick-up process are performed in this order (hereinafter sometimes referred to as "manufacturing method (1)"). ) has been described, but the method for manufacturing a workpiece according to the present embodiment is not limited to this (manufacturing method (1)). For example, in the manufacturing method, as described above, the order of performing the heating step and the processing step may be reversed.

<Application process>
In such a method for manufacturing a workpiece (hereinafter sometimes referred to as "manufacturing method (2)"), a pasting step is first performed. The pasting step of manufacturing method (2) is the same as the pasting step of manufacturing method (1).

<Processing process>
After the pasting step of manufacturing method (2), in the processing step, a semiconductor chip, which is a workpiece, is produced by dividing the semiconductor wafer in an unheated semiconductor wafer with a support sheet fixed to a ring frame. do. Through the processing process, the same group of semiconductor chips with support sheets as in the case of manufacturing method (1) is obtained, except that heating is not performed.

When the adhesive force (X0) of the support sheet is 2000 mN/25 mm or more, the semiconductor wafer may be divided into small-sized semiconductor chips at high speed in the processing process, or the cutting obtained by such division may be By washing small-sized semiconductor chips that have a lot of debris attached to them with water under high water pressure, peeling of the semiconductor chip from the support sheet (adhesive layer) is suppressed even if a large force is applied to the semiconductor chip. .

<Heating process>
After the pasting step and processing step of manufacturing method (2), in the heating step, the adhesive layer in the support sheet fixed to the ring frame is heated. The heating of the adhesive layer in this case is accompanied by the heating of the entire semiconductor chip group with the support sheet. By this heating, for example, foreign matter such as a low molecular weight resin component adhering to the surface of the semiconductor chip (for example, the circuit surface) can be removed by volatilization. Moreover, after cleaning and removing fine foreign matter generated during dicing of a semiconductor wafer and attached to the surface of a semiconductor chip with water, the semiconductor chip, etc. can be dried by this heating. Through the heating step, a semiconductor chip group with a support sheet similar to that in manufacturing method (1) is obtained.

In the support sheet, the adhesive force (Y2) is 13000 mN/25 mm or more, so that even if the group of semiconductor chips with the support sheet is heated while being fixed to the ring frame in the heating step, the semiconductor chips with the support sheet are Peeling of the group from the ring frame is suppressed.

In the support sheet, when the adhesive force (X2) is 13000 mN/25 mm or more, the support sheet with the semiconductor chips attached (in other words, the group of semiconductor chips with the support sheet) is heated to 135 mm in the heating step. Even if a large force is applied to the semiconductor chip after heating it at a high temperature with an upper limit of about 0.degree. C., peeling of the semiconductor chip from the support sheet (adhesive layer) is suppressed.

<Curing process>
After the heating step and the processing step of manufacturing method (2), the curing step can be performed in the same manner as in manufacturing method (1), and the curing step results in the same results as in manufacturing method (1). A group of semiconductor chips with a cured support sheet is obtained.

In the support sheet, when the adhesive force (Y1) is 300 mN/25 mm or more, the support sheet with the semiconductor chips attached (in other words, the group of semiconductor chips with the support sheet) is attached to the ring frame in the heating step. Even if the ring of the semiconductor chip group with the cured support sheet is heated while being fixed to the ring frame, and even if the contact part of the support sheet (adhesive layer) with the ring frame is irradiated with energy rays during the curing process, the ring of the semiconductor chip group with the cured support sheet Peeling from the frame is suppressed.

<Pickup process>
After the curing step of manufacturing method (2), the pickup step can be performed in the same manner as in manufacturing method (1), and the pickup step achieves the same objective as in manufacturing method (1). The semiconductor chip can be taken out.

In the support sheet, the adhesive force (X1) is 400 mN/25 mm or less, so that in the heating step, even after the semiconductor chip group with the support sheet is heated at a high temperature with an upper limit of about 135 ° C. , the semiconductor chip can be normally picked up from the cured support sheet, and the pick-up property is high.

<Other processes>
Manufacturing method (2) may include other steps similar to those in manufacturing method (1).
In the manufacturing method (2) as well, the type of the other steps, the number of the other steps, and the timing of performing the other steps can all be arbitrarily selected depending on the purpose and are not particularly limited.

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

<Resin manufacturing raw materials>
The official names of the raw materials for resin production, which are abbreviated in the examples and comparative examples, are shown below.
2EHA: 2-ethylhexyl acrylate 2EHMA: 2-ethylhexyl methacrylate HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate MOI: 2-methacryloyloxyethyl isocyanate

<Raw materials for producing adhesive composition (I)>
In the present Examples and Comparative Examples, the manufacturing raw materials used in manufacturing the adhesive composition (I) are shown below.
The viscosity at 23° C. of the four types of crosslinking agents (β) was measured using a digital rotational viscometer “Viscoread Advance” manufactured by Viscotec.
[Energy ray curable compound (α)]
(α)-1:2-(2-phenoxyethoxy)ethyl acrylate, “AMP-20GY” manufactured by Shin Nakamura Chemical Co., Ltd., viscosity at 23°C 18 mPa・s, molecular weight 236.1
(α)-2: “R-684” manufactured by Nippon Kayaku Co., Ltd., viscosity 180 mPa・s at 23°C, molecular weight 304.4)
(α)-3: (2-(1-(acryloyloxy)-2-methylpropan-2-yl)-5-ethyl-1,3-dioxan-5-yl)methyl acrylate, manufactured by Shin Nakamura Chemical Co., Ltd. "A-DOG", viscosity at 23°C 310 mPa・s, molecular weight 326.4)
[Crosslinking agent (β)]
Trimethylolpropane adduct of (β)-1:1,6-hexamethylene diisocyanate (“Coronate HL” manufactured by Tosoh Corporation)
(β)-2: Isocyanurate modified product of hexamethylene diisocyanate (“Coronate HX” manufactured by Tosoh Corporation)
[Photopolymerization initiator (γ)]
(γ)-1:2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one (manufactured by IGM Resins, “Omnirad (registered) Trademark) 127'')

Note that the energy ray-curable compounds (α)-1 and (α)-3 are both acrylic esters having a substituent. In energy ray-curable compound (α)-1, the number of substituents in the hydrocarbon group derived from alcohol is 2, and the number of carbon atoms in the hydrocarbon group is 12. In energy ray-curable compound (α)-3, the number of substituents in the hydrocarbon group derived from alcohol is 2, and the number of carbon atoms in the hydrocarbon group is 13.
On the other hand, energy ray curable compound (α)-2 is an acrylic ester having no substituents. In energy ray curable compound (α)-2, the hydrocarbon group derived from alcohol has 12 carbon atoms.

[Example 1]
<<Manufacture of support sheet>>
<Production of energy ray curable acrylic resin (Ia)>
Energy ray-curable acrylic resin (Ia)-1 was obtained by adding MOI to acrylic polymer (1) and carrying out an addition reaction at 50° C. for 48 hours in an air stream. The acrylic polymer (1) is a copolymer of 2EHA (35 parts by mass), 2EHMA (45 parts by mass), and HEMA (20 parts by mass). The amount of MOI used was such that the total number of moles of isocyanate groups in MOI was 0.95 times the total number of moles of hydroxyl groups derived from HEMA in the acrylic polymer (1). The weight average molecular weight of the obtained energy beam curable acrylic resin (Ia)-1 is 440,000, and the glass transition temperature is -26°C.

<Production of adhesive composition (I)>
Energy ray curable acrylic resin (Ia)-1 (100 parts by mass), energy ray curable compound (α)-1 (15 parts by mass), crosslinking agent (β)-1 (1.17 parts by mass), and light An energy ray-curable adhesive that contains polymerization initiator (γ)-1 (3 parts by mass), further contains methyl ethyl ketone as a solvent, and has a total concentration of 25% by mass of all components other than the solvent. Composition (I)-1 was prepared. Note that all the contents of components other than methyl ethyl ketone shown here are the contents of the target product without solvent.

<Formation of adhesive layer>
Using a release film (second release film) in which one side of a polyethylene terephthalate film has been subjected to release treatment by silicone treatment, the adhesive composition (I)-1 obtained above is applied to the release treatment surface. By heating and drying at 100° C. for 2 minutes, an energy ray-curable adhesive layer having a thickness of 15 μm was formed.

<Manufacture of support sheet>
Next, at room temperature, a polypropylene film (manufactured by Dia Plus Film Co., Ltd., thickness 80 μm) was applied as a base material to the exposed surface of the adhesive layer at a sticking speed of 5 m/min and a pressure of 0.4 MPa was applied. Pasted together. One surface of this polypropylene film is a matte surface with a surface roughness (Ra) of 0.90 μm, and the other surface is a slightly matte surface with a surface roughness (Ra) of 0.12 μm. The adhesive layer was attached to the matte surface of this polypropylene film.
Through the above steps, the desired support sheet was obtained.

<<Evaluation of support sheet>>
<Measurement of the adhesive force (X1) between the energy ray-cured adhesive layer and the silicon mirror wafer after heating>
A test piece with a width of 25 mm was cut out from the support sheet obtained above.
This test piece was bonded to the adhesive layer in the bonding temperature condition of 23℃ (laminate roller temperature 23℃, silicon mirror wafer temperature 23℃), the bonding speed was 300 mm/min, and the bonding pressure was 0.3 MPa. The sample was attached to the mirror surface of a silicon mirror wafer (thickness: 650 nm) to obtain a silicon mirror wafer with a test piece. This silicon mirror wafer with a test piece was placed inside an oven whose temperature was adjusted to 130°C, and heated at this temperature (130°C) for 2 hours.
Next, the silicon mirror wafer with the test piece was taken out of the oven and allowed to cool until the temperature reached 23°C. Then, using an ultraviolet irradiation device (RAD-2000UV manufactured by Lintec Corporation), the adhesive layer in the silicon mirror wafer with the test piece taken out was exposed to the conditions of illumination intensity of 230 mW/cm ² and light intensity of 200 mJ/cm ² . By irradiating ultraviolet light through the base material, the adhesive layer in the test piece was cured with ultraviolet light.

Next, the test piece was peeled from the silicon mirror wafer at a peeling rate of 300 mm/min in an environment of 23°C. At this time, the test piece is stretched along its length so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted form an angle of 180°. (180° peeling was performed). Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Excluded from valid values. Then, the average value of the measured values was adopted as the adhesive force (mN/25 mm).
The adhesive force was measured twice, and the average value was adopted as the adhesive force (X1) (mN/25 mm) between the energy ray cured material of the adhesive layer after heating and the silicon mirror wafer. did. The results are shown in Table 1.

<Measurement of adhesive force (X2) between adhesive layer and silicon mirror wafer after heating>
A silicon mirror wafer with a test piece was prepared in the same manner as when measuring the adhesive strength (X1) above, heated at 130°C for 2 hours, and allowed to cool until the temperature reached 23°C.
Next, the test piece was peeled from the cooled silicon mirror wafer at a peeling rate of 300 mm/min in an environment of 23°C. At this time, the test piece is stretched along its length so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted form an angle of 180°. (180° peeling was performed). Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Excluded from valid values. Then, the average value of the measured values was adopted as the adhesive force (mN/25 mm).
The adhesive force was measured twice, and the average value was taken as the adhesive force (X2) (mN/25 mm) between the heated adhesive layer and the silicon mirror wafer. The results are shown in Table 1.

<Measurement of adhesive force (Y1) between the energy ray cured product of the adhesive layer and the SUS plate after heating>
The test piece was attached to the #1200 polished surface of a SUS plate ("SUS304 #1200HL, manufactured by Paltech, thickness 1000 μm, size 70 mm x 150 mm") instead of the mirror surface of the silicon mirror wafer. A SUS plate with a test piece was obtained in the same manner as in the measurement of the adhesive force (X1) described above except for this point.
Next, this SUS plate with a test piece was heated at 130°C for 2 hours in the same manner as in the case of the silicon mirror wafer with a test piece when measuring the adhesive strength (X1) above, and then allowed to cool until the temperature reached 23°C. The adhesive layer in the test piece was cured by ultraviolet rays by irradiating the adhesive layer in the SUS plate with the test piece through the base material.

Next, the test piece was peeled from the SUS plate at a peeling rate of 300 mm/min in an environment of 23°C. At this time, move the test piece in its length direction so that the surface of the SUS plate to which the test piece was pasted and the surface of the test piece to which the SUS board was pasted form an angle of 180°. It was peeled off (180° peeling was performed). Then, the load (peel force) during this 180° peeling was measured, and assuming that the measurement length was 50 mm, the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Excluded from valid values. Then, the average value of the measured values was adopted as the adhesive force (mN/25 mm).
The adhesive force was measured twice, and the average value was adopted as the adhesive force (Y1) (mN/25 mm) between the energy ray-cured adhesive layer and the SUS plate after heating. . The results are shown in Table 1.

<Measurement of adhesive force (Y2) between adhesive layer and SUS board after heating>
A SUS plate with a test piece was prepared in the same manner as when measuring the adhesive force (Y1) above, heated at 130°C for 2 hours, and allowed to cool until the temperature reached 23°C.
Next, the test piece was peeled from the cooled SUS plate at a peeling rate of 300 mm/min in an environment of 23°C. At this time, move the test piece in its length direction so that the surface of the SUS plate to which the test piece was pasted and the surface of the test piece to which the SUS board was pasted form an angle of 180°. It was peeled off (180° peeling was performed). Then, the load (peel force) during this 180° peeling was measured, and the measurement length was set to 50 mm, and the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Excluded from valid values. Then, the average value of the measured values was adopted as the adhesive force (mN/25 mm).
The adhesive force was measured twice, and the average value at that time was adopted as the adhesive force (Y2) (mN/25 mm) between the adhesive layer and the SUS plate after heating. The results are shown in Table 1.

<Measurement of adhesive force (X0) between adhesive layer and silicon mirror wafer>
A silicon mirror wafer with a test piece was prepared in the same manner as in the measurement of the adhesive force (X1) described above.
Next, this silicon mirror wafer with a test piece was stored for 30 minutes at a temperature of 23°C.
Next, the test piece was peeled off from the silicon mirror wafer that had been stored stationary in an environment of 23° C. at a peeling speed of 300 mm/min. At this time, the test piece is stretched along its length so that the surface of the silicon mirror wafer to which the test piece was pasted and the surface of the test piece to which the silicon mirror wafer was pasted form an angle of 180°. (180° peeling was performed). Then, the load (peel force) during this 180° peeling was measured, and assuming that the measurement length was 50 mm, the measured value at the first length of 5 mm and the measured value at the final length of 5 mm were as follows. Excluded from valid values. Then, the average value of the measured values was adopted as the adhesive force (mN/25 mm).
The adhesive force was measured twice, and the average value was taken as the adhesive force (X0) (mN/25 mm) between the adhesive layer and the silicon mirror wafer. The results are shown in Table 1.

<Calculation of average value of light transmittance (400 to 800 nm) of support sheet>
Using a UV-vis measurement device ("UV-vis-NIR3600" manufactured by Shimadzu Corporation), the support sheet obtained above was irradiated with light from the outside on the base material side, and an integrating sphere was used. The light transmittance was measured by direct light reception. The wavelength range of the measurement at this time was 190 to 2000 nm. Then, add up the light transmittance values for each 1 nm in the wavelength range of 400 to 800 nm in the visible light region, and calculate the total value by the number of combined light transmittance values (i.e., 800-400+1=401). By dividing, the average value (%) of the light transmittance (400 to 800 nm) of the support sheet was calculated. The results are shown in Table 1.

<Evaluation of the effect of suppressing peeling of the support sheet from the ring frame after heating>
A 12-inch silicon wafer (thickness: 500 μm) was prepared. Of the adhesive layer in the support sheet obtained above, a region closer to the center in the width direction was attached to the silicon wafer, and a region surrounding the region attached to the silicon wafer was attached to a ring frame. At this time, the adhesive layer was attached to the silicon wafer and the ring frame at a bonding temperature of 23°C (laminate roller temperature 23°C, silicon wafer temperature 23°C), and a bonding speed of 300 mm/min. The pressure was set to 0.3 MPa. As a result, a silicon wafer with a support sheet, which included a silicon wafer and a support sheet provided on one surface of the silicon wafer, was fixed to the ring frame.
Next, the silicon wafer with the support sheet fixed to the ring frame was placed inside the oven. At this time, the silicon wafer with the support sheet fixed to the ring frame was placed so that the exposed surface of the silicon wafer (the surface opposite to the side with the support sheet) was horizontal, and in this state, the silicon wafer was heated to 130°C. It was heated for 2 hours.

Next, the silicon wafer with the support sheet fixed to the ring frame is taken out of the oven, and from the outside of the base material side of the support sheet, the presence or absence of peeling of the support sheet from the ring frame, and if there is peeling, is checked. The degree of damage was visually confirmed. When the silicon wafer with a support sheet fixed to the ring frame is arranged as described above, when the support sheet peels off from the ring frame, it peels off from the inner peripheral side of the ring frame. Therefore, if there is separation of the support sheet from the ring frame, identify the separation site where the distance from the inner periphery of the ring frame to the end of the separation area of the support sheet is the maximum, that is, the separation site with the maximum separation distance. In addition to the presence or absence of peeling, the effect of suppressing peeling of the support sheet from the ring frame after heating was evaluated based on the maximum peeling distance and according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: There is no peeling of the support sheet from the ring frame, or even if there is peeling, the maximum peeling distance is 2 mm or less, and the effect of suppressing peeling is high.
B: There was peeling of the support sheet from the ring frame, and the maximum peeling distance was more than 2 mm and 5 mm or less, and the effect of suppressing peeling was low.
C: There was peeling of the support sheet from the ring frame, the maximum peeling distance was more than 5 mm, and the effect of suppressing peeling was particularly low.

<Evaluation of silicon chip pick-up performance of support sheet>
(Manufacture of silicon chip group with support sheet)
An 8-inch silicon wafer (thickness: 350 μm) with one side polished to #2000 was prepared. Of the adhesive layer in the support sheet obtained above, a region closer to the center in the width direction was attached to the silicon wafer, and a region surrounding the region attached to the silicon wafer was attached to a ring frame. At this time, the adhesive layer was attached to the silicon wafer and the ring frame at a bonding temperature of 23°C (laminate roller temperature 23°C, silicon wafer temperature 23°C), and a bonding speed of 300 mm/min. The pressure was set to 0.3 MPa. As a result, a silicon wafer with a support sheet, which included a silicon wafer and a support sheet provided on one surface of the silicon wafer, was fixed to the ring frame (attaching step).
Next, the silicon wafer with the support sheet fixed to the ring frame was placed inside an oven and heated at 130° C. for 2 hours (heating step). At this time, the silicon wafer with the support sheet fixed to the ring frame was placed inside the oven so that the exposed surface of the silicon wafer (the surface opposite to the side provided with the support sheet) was horizontal.

Next, the silicon wafer with the support sheet fixed to the ring frame was taken out of the oven and allowed to cool until the temperature reached 23°C. Then, a plurality of silicon chips each having a size of 3 mm x 3 mm were produced by dicing the silicon wafer in the silicon wafer with a support sheet fixed to a ring frame using a dicing device ("DFD6362" manufactured by Disco Corporation). processing process). At this time, a dicing blade "ZH05-SD2000-N1-90 CC" manufactured by DISCO was used, and the blade rotation speed was 35000 rpm, the blade feed speed was 30 mm/s, and the blade height was 0.06 mm. A blade was inserted into the wafer from the surface on the silicon wafer side, and a cut was made to a depth of 20 μm from the surface of the base material on the adhesive layer side.
As described above, a silicon chip group with a support sheet was produced in which a plurality of silicon chips were aligned and held on one support sheet.

(Evaluation of silicon chip pick-up performance of support sheet)
Next, using an ultraviolet irradiation device ("RAD-2000UV" manufactured by Lintec Corporation), the adhesive layer in the group of silicon chips with support sheets was irradiated with an illumination intensity of 230 mW/230 mW from outside the base material side. cm ² and a light intensity of 200 mJ/cm ² , the adhesive layer attached to the ring frame was cured with ultraviolet light (curing step).
Next, using a pick-up die bonding device ("BESTEM D-510" manufactured by Canon Machinery), the silicon chips of the silicon chip group with the cured support sheet were separated from the cured adhesive layer under the following pick-up conditions. and picked it up (pickup process). This pickup picks up a total of 100 silicon chips in 10 rows in two orthogonal directions, which are divided from the center and the vicinity of the center of the silicon wafer before dicing, among the silicon chips in the group of silicon chips with cured support sheets. The test was performed on individual silicon chips using a method in which one silicon chip was pushed up from the support sheet side using one pin. Then, the pick-up properties of the support sheet were evaluated according to the following criteria. The results are shown in Table 1.
(Pickup conditions)
Thrusting speed: 5mm/s
Expand amount: 4mm
Curvature radius of pin tip: 0.75mm
(Evaluation criteria)
A: All (100) silicon chips were successfully picked up.
B: 1 to 4 silicon chips could not be picked up normally, but all other silicon chips (96 to 99 pieces) could be picked up normally.
C: Five or more silicon chips could not be picked up normally.

[Example 2]
<<Manufacture and evaluation of support sheet>>
Energy ray curable compound (α)-3 (10 parts by mass) is contained instead of energy ray curable compound (α)-1 (15 parts by mass), and the content of crosslinking agent (β)-1 is 1 Energy ray-curable adhesive composition (I)-2 was prepared having the same composition as in Example 1, except that the amount was 1.33 parts by mass instead of 0.17 parts by mass. A support sheet was produced and evaluated in the same manner as in Example 1, except that this adhesive composition (I)-2 was used instead of adhesive composition (I)-1. The results are shown in Table 1.

[Example 3]
<<Manufacture and evaluation of support sheet>>
Energy ray curable compound (α)-2 (10 parts by mass) is contained instead of energy ray curable compound (α)-1 (15 parts by mass), and the content of crosslinking agent (β)-1 is 1 Energy ray-curable adhesive composition (I)-3 was prepared having the same composition as in Example 1, except that the amount was 1.33 parts by mass instead of 0.17 parts by mass. A support sheet was produced and evaluated in the same manner as in Example 1, except that this adhesive composition (I)-3 was used instead of adhesive composition (I)-1. The results are shown in Table 1.

[Reference example 1]
<<Manufacture of support sheet>>
<Production of energy ray curable acrylic resin (Ia)>
Energy ray-curable acrylic resin (Ia)-2 was obtained by adding MOI to the acrylic polymer (1) and carrying out an addition reaction at 50° C. for 48 hours in an air stream. The amount of MOI used was such that the total number of moles of isocyanate groups in MOI was 0.785 times the total number of moles of hydroxyl groups derived from HEMA in the acrylic polymer (1). The weight average molecular weight of the obtained energy beam curable acrylic resin (Ia)-2 was 500,000, and the glass transition temperature was -26°C.

<Production of adhesive composition (I)>
Energy ray curable acrylic resin (Ia)-2 (100 parts by mass), energy ray curable compound (α)-1 (25 parts by mass), crosslinking agent (β)-2 (4.12 parts by mass), and light An energy ray-curable adhesive that contains polymerization initiator (γ)-1 (3 parts by mass), further contains methyl ethyl ketone as a solvent, and has a total concentration of 25% by mass of all components other than the solvent. Composition (R)-1 was prepared. Note that all the contents of components other than methyl ethyl ketone shown here are the contents of the target product without solvent.

<Manufacture of support sheet>
A support sheet was produced in the same manner as in Example 1, except that this adhesive composition (R)-1 was used in place of adhesive composition (I)-1.

<<Evaluation of support sheet>>
The support sheet obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative example 1]
<<Manufacture of support sheet>>
<Manufacture of adhesive composition>
Contains energy ray curable acrylic resin (Ia)-1 (100 parts by mass), crosslinking agent (β)-1 (0.53 parts by mass), and photoinitiator (γ)-1 (3 parts by mass). An energy ray-curable pressure-sensitive adhesive composition (R)-2 was prepared which further contained methyl ethyl ketone as a solvent and had a total concentration of 25% by mass of all components other than the solvent. Note that all the contents of components other than methyl ethyl ketone shown here are the contents of the target product without solvent.

<Manufacture of support sheet>
A support sheet was produced in the same manner as in Example 1, except that this adhesive composition (R)-2 was used in place of adhesive composition (I)-1.

<<Evaluation of support sheet>>
The support sheet obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative example 2]
<<Manufacture of support sheet>>
<Production of energy ray curable acrylic resin (Ia)>
Energy ray-curable acrylic resin (Ia)-3 was obtained by adding MOI to acrylic polymer (2) and carrying out an addition reaction at 50° C. for 48 hours in an air stream. The acrylic polymer (2) is a copolymer of 2EHA (35 parts by mass), 2EHMA (45 parts by mass), and HEA (20 parts by mass). The amount of MOI used was such that the total number of moles of isocyanate groups in MOI was 0.7 times the total number of moles of hydroxyl groups derived from HEA in the acrylic polymer (2). The weight average molecular weight of the obtained energy ray curable acrylic resin (Ia)-3 was 880,000, and the glass transition temperature was -35°C.

<Manufacture of adhesive composition>
Contains energy ray curable acrylic resin (Ia)-3 (100 parts by mass), crosslinking agent (β)-1 (9.26 parts by mass), and photoinitiator (γ)-1 (3 parts by mass). An energy ray-curable adhesive composition (R)-3 was prepared which further contained methyl ethyl ketone as a solvent and had a total concentration of 25% by mass of all components other than the solvent. Note that all the contents of components other than methyl ethyl ketone shown here are the contents of the target product without solvent.

<Manufacture of support sheet>
A support sheet was produced in the same manner as in Example 1, except that this adhesive composition (R)-3 was used in place of adhesive composition (I)-1.

<<Evaluation of support sheet>>
The support sheet obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from the above results, in Examples 1 to 3, the adhesive force (Y2) is 15,600 mN/25 mm or more, which is sufficiently large, and reflecting this, the silicon wafer with the support sheet fixed to the ring frame is heated at high temperature. Even when heated, peeling of the support sheet from the ring frame could be highly suppressed, and the effect of suppressing peeling was high.
Furthermore, in Examples 1 to 3, the adhesive strength (X1) was 200 mN/25 mm or less, and even after heating the support sheet to which the silicon mirror wafer was attached at 130°C for 2 hours, the silicon chip In general, all of them were picked up normally, and the pickup performance was high.
Thus, the support sheets of Examples 1 to 3 had the desired properties.

In Examples 1 to 3, the adhesive composition (I) contained an energy ray curable acrylic resin (Ia) and an energy ray curable compound (α), and the above characteristics could be easily achieved. Guessed. In particular, it was speculated that the above properties could be achieved more easily because the energy ray curable compound (α) had a structure within a specific range. Furthermore, in Examples 1 to 3, it was assumed that the crosslinking agent (β) also had a structure within a specific range, making it easier to achieve the above characteristics.

Furthermore, in Examples 1 to 3, the adhesive force (X2) is 15000 mN/25 mm or more, and is sufficiently large, and after heating the silicon wafer with a support sheet at high temperature, dicing of silicon mirror wafers and silicon chips after dicing. Even when a large force was applied to the silicon chip by washing with water, peeling of the silicon chip from the support sheet was suppressed.
Furthermore, in Examples 1 to 3, the adhesive force (X0) is 2900 mN/25 mm or more, which is sufficiently large, and it is difficult to use, for example, when dicing silicon mirror wafers at high speed or washing silicon chips after dicing with water under high pressure. It was speculated that even if a significantly large force is applied to the silicon chip, peeling of the silicon chip from the support sheet can be suppressed.

In particular, in Examples 1 and 2, the adhesive strength (Y1) was 470 mN/25 mm or more, which was significantly large. The support sheets of Examples 1 and 2 were fixed to a ring frame in the form of a silicon wafer with a support sheet, heated, and then an energy beam was irradiated on the contact portion of the support sheet (adhesive layer) with the ring frame. It was presumed that even if the silicon chips with the cured support sheet were removed from the ring frame, it would be possible to prevent them from peeling off.

Furthermore, in Examples 1 to 3, the average value of the light transmittance (400 to 800 nm) of the support sheet was 81.4% or more, which was sufficiently high and had desirable characteristics.

As described above, the support sheets of Examples 1 to 3 were more preferable because they also had excellent properties other than the intended ones.

On the other hand, in Reference Example 1, the adhesive strength (Y2) is small, and reflecting this, after heating the silicon wafer with the support sheet fixed to the ring frame at high temperature, the peeling of the support sheet from the ring frame is difficult. The suppression effect was particularly low.
In addition, in Reference Example 1, the adhesive force (X1) was 350 mN/25 mm, and the pick-up property of the silicon chip after heating the support sheet with the silicon mirror wafer attached at 130°C for 2 hours was as follows. It was worse than 1-3.

Furthermore, in Reference Example 1, the adhesive force (X2) is small, and after heating the silicon wafer with a support sheet at high temperature, a large force is applied to the silicon chip by dicing the silicon mirror wafer, washing the silicon chip with water after dicing, etc. It was surmised that when added, peeling of the silicon chips from the support sheet could not be suppressed.
Furthermore, in Reference Example 1, the adhesive force (X0) is small, and a significantly large force is applied to the silicon chip, for example, by dicing a silicon mirror wafer at high speed or washing the silicon chip with water at high pressure after dicing. It was presumed that peeling of the silicon chip from the support sheet could not be suppressed even when the silicon chip was removed.

In Comparative Examples 1 and 2, the adhesive strength (Y2) was 12000 mN/25 mm or less, which was small. The effect of suppressing peeling from the surface was low.
In Comparative Examples 1 and 2, the energy ray curable compound (α) was not used.

In addition, in Comparative Example 2, the adhesive strength (X1) was large, and after heating the support sheet to which the silicon mirror wafer was attached at 130°C for 2 hours, the silicon chips could not be picked up normally, and the pick-up performance was low. Ta.

Furthermore, in Comparative Example 1, the adhesive force (Y1) is also insufficient, and this support sheet is insufficiently effective in suppressing peeling from the ring frame even in the state of the silicon chip group with the cured support sheet. It was speculated that.
Furthermore, in Comparative Example 2, the adhesive force (X2) is small, and after heating the silicon wafer with a support sheet at high temperature, a large force is applied to the silicon chip by dicing the silicon mirror wafer, washing the silicon chip with water after dicing, etc. It was presumed that the effect of suppressing the peeling of silicon chips from the support sheet when added was low.

The present invention can be used for manufacturing workpieces such as semiconductor chips.

DESCRIPTION OF SYMBOLS 1... Support sheet, 11... Base material, 11a... One side of the base material, 12... Adhesive layer, 12'... Energy ray cured product, 8... Ring frame, 9... Semiconductor wafer, 90... Semiconductor chip, 109... Semiconductor wafer with support sheet

Claims (6)

A support sheet,
The support sheet includes a base material and an adhesive layer provided on one surface of the base material,
the adhesive layer is energy ray curable,
The support sheet is pasted on the surface of the stainless steel plate using the adhesive layer, and the adhesive layer after pasting is heated at 130° C. to reduce the adhesion between the heated adhesive layer and the stainless steel plate. When the force (Y2) is measured, the adhesive force (Y2) is 13000 mN/25 mm or more,
The supporting sheet is pasted on the mirror surface of the silicon mirror wafer using the adhesive layer, the adhesive layer after pasting is heated at 130° C., the heated adhesive layer is cured with energy rays, and the adhesive layer is cured with energy rays. A support sheet having an adhesive force (X1) of 400 mN/25 mm or less when the adhesive force (X1) between the energy ray cured layer and the silicon mirror wafer is measured. The support sheet according to claim 1, wherein the adhesive layer contains an energy ray curable compound and an energy ray curable acrylic resin. The support sheet is pasted on the surface of a stainless steel plate using the adhesive layer, the adhesive layer after pasting is heated at 130° C., the heated adhesive layer is cured with energy rays, and the adhesive layer is cured with energy rays. The support sheet according to claim 1 or 2, wherein when the adhesive force (Y1) between the energy ray cured product and the stainless steel plate is measured, the adhesive force (Y1) is 300 mN/25 mm or more. The support sheet is pasted on the mirror surface of the silicon mirror wafer using the adhesive layer, and the adhesive layer after pasting is heated at 130° C., so that the adhesive layer after heating and the silicon mirror wafer are separated. The support sheet according to any one of claims 1 to 3, wherein the adhesive force (X2) is 13000 mN/25 mm or more when measured. The support sheet was attached to the mirror surface of the silicon mirror wafer using the adhesive layer, and the silicon mirror wafer with the support sheet was stored for 30 minutes at a temperature of 23° C., and the adhesive layer was attached to the silicon mirror wafer. and the silicon mirror wafer, the support sheet according to any one of claims 1 to 4, wherein the adhesive force (X0) is 2000 mN/25 mm or more when measured. . A method for manufacturing a workpiece, the method comprising:
The manufacturing method includes: attaching the adhesive layer in the support sheet according to any one of claims 1 to 5 to a workpiece and a ring frame; a pasting step of fixing a support sheet-attached workpiece comprising a sheet to the ring frame;
After the pasting step, a heating step of heating the adhesive layer in the support sheet fixed to the ring frame;
After the pasting step, a processing step of producing the workpiece by processing the workpiece in the workpiece with the support sheet fixed to the ring frame;
After the heating step and the processing step, a curing step of curing the adhesive layer attached to the ring frame with energy rays;
A method for manufacturing a workpiece, comprising, after the curing step, a pickup step of separating and picking up the workpiece from the cured product of the adhesive layer.

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