JP2022136874A - Semiconductor processing sheet - Google Patents

Abstract

To provide a semiconductor processing sheet with excellent efficiency for suppressing an attachment of a cut piece to a chip.SOLUTION: A semiconductor processing sheet comprises: a base material; and a semiconductor adhesive layer laminated on one surface side in the base material. In a test piece obtained by cutting out the semiconductor processing sheet in a rectangle shape having 60 mm of a long side and 15 mm of a short size, and cutting the semiconductor processing sheet from a surface side of the semiconductor adhesive layer up to 40 μm of a remaining thickness of the base material in parallel to the short side at a position of a center of the long side, a breaking ductility measures under each environment of 23°C and 50°C satisfies the following equation (1): a breaking ductility under 50°C/a breaking ductility under 23°C≥3.0 ...(1) in the case where a tension test is performed in 30 mm of an inter-chuck distance and 1000 mm/min of a tension speed under each environment of 23°C and 50°C.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a semiconductor processing sheet used for processing semiconductor wafers and the like.

Semiconductor wafers such as silicon and gallium arsenide and various packages (hereinafter sometimes referred to as "workpieces") are manufactured in a large diameter state, cut (diced) into chips, and peeled off (picked up). Afterwards, it is transferred to the mounting process, which is the next process. At this time, the workpiece such as a semiconductor wafer is laminated on a sheet (hereinafter sometimes referred to as "semiconductor processing sheet") including a base material and a semiconductor adhesion layer such as an adhesive layer. , back grinding, dicing, washing, drying, expanding, picking up, mounting, etc.

In full-cut dicing, which is general as a specific method of dicing described above, a workpiece is cut by a rotating round blade (dicing blade). Usually, not only the workpiece but also the semiconductor bonding layer are cut so that the workpiece laminated on the semiconductor processing sheet is surely cut, and a part of the base material is also cut. At this time, cut pieces made of the materials constituting the semiconductor adhesion layer and the base material may be generated from the semiconductor processing sheet, and the cut pieces may contaminate the workpiece after cutting. One of the typical forms of the cut pieces is a thread-like cut piece attached on the dicing line or near the cross section of the chip separated by dicing.

If the chip is sealed while a large amount of the thread-like cutting pieces adheres to the chip, the thread-like cutting pieces adhering to the chip are decomposed by the heat of the sealing, and this thermal decomposition product may damage the package or cause damage. It may cause malfunction in the device that is used. Since it is more difficult to remove the thread-like cutting pieces by cleaning as the size thereof increases, the adhesion of the thread-like cutting pieces significantly reduces the yield of the dicing process. Therefore, when a semiconductor processing sheet is used for dicing, it is required to prevent the thread-like cutting pieces from adhering to the chips.

For the purpose of suppressing the adhesion of cut pieces, Patent Document 1 discloses the use of a polyolefin film obtained by irradiating electron beams under predetermined conditions as a base film for a dicing sheet.

JP 2014-187244 A

However, under the circumstances where the miniaturization of semiconductor devices is progressing more and more, there is a demand for a semiconductor processing sheet that can further suppress adhesion of cut pieces.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor processing sheet which is excellent in the effect of suppressing the adhesion of chips to chips.

To achieve the above object, firstly, the present invention provides a semiconductor processing sheet comprising a substrate and a semiconductor attachment layer laminated on one side of the substrate, wherein the semiconductor processing sheet is elongated. A rectangle with a side of 60 mm and a short side of 15 mm is cut out, and a notch parallel to the short side is made at the center of the long side from the surface side of the semiconductor adhesion layer until the remaining thickness of the base material reaches 40 μm. Tensile test was performed on the test piece under environments of 23°C and 50°C at a distance between chucks of 30 mm and a tensile speed of 1000 mm/min. The degree is the following formula (1)
Breaking elongation at 50°C/breaking elongation at 23°C ≥ 3.0 (1)
(Invention 1).

The semiconductor processing sheet according to the invention (Invention 1) satisfies the above-described conditions regarding the elongation at break, so that adhesion of cut pieces to the chip can be satisfactorily suppressed.

In the above invention (invention 1), when the tensile test is performed on the test piece, the breaking energy measured under each environment of 23 ° C. and 50 ° C. is expressed by the following formula (2)
Breaking energy at 50°C/breaking energy at 23°C ≥ 2.0 (2)
(Invention 2).

In the above inventions (inventions 1 and 2), the material of the base preferably contains at least one of polyolefin resin and polyvinyl chloride resin (invention 3).

In the above inventions (inventions 1 to 3), the semiconductor attachment layer preferably includes at least one of a pressure-sensitive adhesive layer, an adhesive layer and a protective film-forming layer (invention 4).

The above inventions (Inventions 1 to 4) are preferably used for dicing (Invention 5).

When dicing is performed using the semiconductor processing sheet according to the present invention, it is possible to satisfactorily suppress adhesion of cut pieces to chips.

Embodiments of the present invention will be described below.
A semiconductor processing sheet according to the present embodiment includes a substrate and a semiconductor adhesion layer laminated on one side of the substrate.

Then, for the semiconductor processing sheet according to the present embodiment, the breaking elongation (%) at 23 ° C. and the breaking elongation (%) at 50 ° C. measured by performing a predetermined tensile test are expressed by the following formula (1)
Breaking elongation at 50°C/breaking elongation at 23°C ≥ 3.0 (1)
It satisfies

Here, in the tensile test, first, the sheet for semiconductor processing according to the present embodiment is cut into a rectangular shape with a long side of 60 mm and a short side of 15 mm. The cut piece obtained by this cutting is cut parallel to the short side at the center position of the long side from the side of the semiconductor adhesion layer until the remaining thickness of the base material reaches 40 μm. Here, when the semiconductor processing sheet has a release sheet, which will be described later, the release sheet is peeled off and removed. The test pieces thus obtained are subjected to a tensile test under two temperature environments of 23° C. and 50° C. at a distance between chucks of 30 mm and a tensile speed of 1000 mm/min. The elongation at break (%) thus measured is the elongation at break at 23°C and the elongation at break at 50°C according to the above formula (1).

The semiconductor processing sheet according to the present embodiment satisfies the condition of the above formula (1) regarding the elongation at break, so that the cut pieces (especially, thread-like cut pieces) generated when dicing using a dicing blade are attached to the chip. Adhesion can be suppressed satisfactorily. The reason for this is considered as follows. However, it is not limited to the following reasons, and the possibility of complex reasons combined with other events or completely different reasons is not denied.

In normal dicing, the temperature rises to 50° C. or more at the contact portion between the rotating dicing blade and the semiconductor wafer or semiconductor processing sheet due to friction therebetween. At the same time, the rotating dicing blade scrapes up the material to apply a stretching force to the material forming the semiconductor processing sheet at the contact portion. On the other hand, in normal dicing, in order to suppress excessive heating, running water (cutting water) is supplied to the contact portion to cool the dicing blade and the like. Here, since the semiconductor processing sheet according to the present embodiment satisfies the above formula (1), the semiconductor processing sheet can be cut at a low temperature of 23 ° C. compared to a high temperature of 50 ° C. (breakage) is likely to occur. In such a semiconductor processing sheet, the contact portion, that is, the portion to which the stretching force is applied, is easily elongated. On the other hand, at a position distant from the contact portion, the stretching force is weakened, and the cutting water becomes easier to cool away from the heat source, thereby facilitating cutting. As a result, in the case of the semiconductor processing sheet according to the present embodiment, elongated thread-like cut pieces are less likely to occur, and adhesion of the cut pieces to the chip is effectively suppressed.

From the viewpoint of more effectively suppressing adhesion of cut pieces, the above-mentioned ratio of elongation at break (elongation at break at 50°C/elongation at break at 23°C) is preferably 5.0 or more, particularly 6 It is preferably 0.0 or more. The upper limit of the ratio of elongation at break described above is not particularly limited, and may be, for example, 30 or less, particularly 20 or less, or even 10 or less.

Moreover, the elongation at break at 23° C. described above is preferably 10% or more, particularly preferably 20% or more, and further preferably 30% or more. Also, the breaking elongation at 23° C. is preferably 100% or less, particularly preferably 70% or less, further preferably 50% or less. When the elongation at break at 23°C is within these ranges, it becomes easy to achieve the ratio of elongation at break described above.

Furthermore, the elongation at break at 50° C. described above is preferably 100% or more, particularly preferably 200% or more, further preferably 250% or more. Further, the breaking elongation at 50°C is preferably 600% or less, particularly preferably 350% or less, further preferably 300% or less. When the elongation at break at 50°C is within these ranges, it becomes easy to achieve the ratio of elongation at break described above.

Further, in the semiconductor processing sheet according to the present embodiment, a test piece is prepared in the same manner as in the measurement of the elongation at break described above, and the tensile test described above is performed. The following equation (2) for the breaking energy at
Breaking energy at 50°C/breaking energy at 23°C ≥ 2.0 (2)
It is also preferable to satisfy

In particular, the above breaking energy ratio (breaking energy at 50° C./breaking energy at 23° C.) is preferably 2.4 or more, more preferably 5.0 or more. When the ratio of the breaking energies is within these ranges, it becomes easier to satisfy the above-mentioned ratio of breaking elongations, and it becomes easy to effectively suppress adhesion of cut pieces to the tip. The upper limit of the above-mentioned breaking energy ratio is not particularly limited, and may be, for example, 25 or less, particularly 21 or less, or further 10 or less.

The breaking energy at 23° C. described above is preferably 20 N·mm or more, particularly preferably 40 N·mm or more, further preferably 100 N·mm or more. Also, the breaking energy at 23° C. is preferably 300 N·mm or less, particularly preferably 200 N·mm or less, further preferably 150 N·mm or less. When the breaking energy at 23° C. is within these ranges, it becomes easy to achieve the above-mentioned breaking energy ratio.

Furthermore, the breaking energy at 50° C. described above is preferably 300 N·mm or more, particularly preferably 500 N·mm or more, further preferably 700 N·mm or more. Also, the breaking energy at 50° C. is preferably 2000 N·mm or less, particularly preferably 1500 N·mm or less, further preferably 1000 N·mm or less. When the breaking energy at 50° C. is within these ranges, it becomes easy to achieve the above-described breaking energy ratio.

The details of the methods for measuring the breaking elongation and breaking energy are as described in the test examples described later. As described above, in the tensile test for measuring the breaking elongation and breaking energy, cuts are made in the semiconductor processing sheet until the remaining thickness of the base material reaches 40 μm. This does not mean that the thickness of the substrate in the semiconductor processing sheet according to the present embodiment is always 40 μm or more. That is, the thickness of the substrate in this embodiment may be less than 40 μm. When the thickness of the substrate is less than 40 μm, the breaking elongation and breaking energy are measured using a semiconductor processing sheet having a test substrate made of the same material as the substrate and having a thickness of 40 μm or more. shall be measured at

1. Substrate The substrate in the present embodiment is not particularly limited as long as it satisfies the above ratio of elongation at break and can exhibit the desired functions when the semiconductor processing sheet is used.

The base material in the present embodiment is preferably a resin film mainly composed of a resin-based material from the viewpoint of easily satisfying the ratio of elongation at break described above. In particular, the substrate in the present embodiment preferably contains at least one of polyolefin resin and polyvinyl chloride resin. When the base material contains these resins, the semiconductor processing sheet easily satisfies the above-mentioned ratio of elongation at break.

Preferable examples of the polyolefin resin include polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, and norbornene resin. Preferred examples of polyolefin resins include copolymers of ethylene and α-olefins and copolymers of α-olefins and propylene.

Preferred examples of the polyethylene include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and the like. Among these, LDPE and HDPE are preferred.

Preferred examples of the copolymer of ethylene and α-olefin include ethylene-propylene copolymers. As for the ethylene-propylene copolymer, the mass ratio of the ethylene monomer and the propylene monomer constituting the copolymer is preferably 1:99 to 50:50, particularly 5:95 to 40:60. preferably 8:92 to 30:70. By using the ethylene-propylene copolymer having such a structure, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

Among the above resins, it is preferable to use at least one of LDPE, HDPE and ethylene-propylene copolymer from the viewpoint of easily satisfying the above-mentioned ratio of elongation at break. It is preferable to use a mixture of two or more.

When LDPE is used as the base material, the content of LDPE in the base is preferably 5% by mass or more, particularly preferably 10% by mass or more, and further preferably 15% by mass or more. is preferred. Also, the content of LDPE in the substrate is preferably 99% by mass or less, particularly preferably 97% by mass or less, and further preferably 95% by mass or less. When the content of LDPE is within the above range, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

When HDPE is used as the base material, the content of HDPE in the base is preferably 5% by mass or more, particularly preferably 10% by mass or more, and further preferably 15% by mass or more. is preferred. The content of HDPE in the substrate is preferably 90% by mass or less, particularly preferably 80% by mass or less, and further preferably 70% by mass or less. When the content of HDPE is within the above range, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

When an ethylene-propylene copolymer is used as the material for the base material, the content of the ethylene-propylene copolymer in the base material is preferably 5% by mass or more, particularly 10% by mass or more. Preferably, it is 15% by mass or more. The content of the ethylene-propylene copolymer in the substrate is preferably 90% by mass or less, particularly preferably 85% by mass or less, further preferably 80% by mass or less. When the content of the ethylene-propylene copolymer is within the above range, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

Preferable examples of the polyvinyl chloride resin include polyvinyl chloride, polyvinylidene chloride, vinyl chloride/ethylene copolymer, vinyl chloride/vinyl acetate copolymer, and the like. Among these, it is preferable to use polyvinyl chloride from the viewpoint of easily satisfying the ratio of elongation at break described above.

When polyvinyl chloride is used as the material for the substrate, the content of polyvinyl chloride in the substrate is preferably 40% by mass or more, particularly preferably 50% by mass or more, and further preferably 60% by mass. % or more. The content of polyvinyl chloride in the substrate is preferably 99% by mass or less, particularly preferably 97% by mass or less, and more preferably 95% by mass or less. When the content of polyvinyl chloride is within the above range, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

The base material in the present embodiment may contain other resins together with the above resins, or may be made of other resins instead of the above resins. Examples of the other resins include ethylene-vinyl acetate copolymer; ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer, other ethylene-(meth)acrylic acid esters. ethylene copolymers such as copolymers; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; (meth)acrylate copolymers; polyurethanes; polyimides; In addition, "(meth)acrylic acid" in this specification means both acrylic acid and methacrylic acid. The same is true for other similar terms.

The substrate in the present embodiment may be a modified film such as a crosslinked film of a film made of the above resins or an ionomer film. Further, the substrate in the present embodiment may be a laminated film formed by laminating a plurality of films made of the above resins. In this laminated film, the materials constituting each layer may be of the same type or of different types.

The substrate in the present embodiment preferably contains core-shell rubber together with the above resins. In particular, when the substrate in the present embodiment contains a polyvinyl chloride resin (especially polyvinyl chloride), it preferably contains a core-shell rubber.

Examples of the core-shell rubber include methacrylate/styrene/butadiene rubber graft copolymer, methacrylate/styrene/styrene/butadiene rubber graft copolymer, acrylonitrile/styrene/butadiene rubber graft copolymer, and acrylonitrile/styrene. /styrene-butadiene rubber graft copolymer, acrylonitrile-styrene/ethylene-propylene rubber graft copolymer, acrylonitrile-styrene/acrylate rubber graft copolymer, methacrylate/acrylate rubber graft copolymer, methacrylic Acid ester/styrene/acrylic acid ester rubber graft copolymer, methacrylic acid ester/acrylonitrile/acrylic acid ester rubber graft copolymer, and the like. Among these, a methacrylate/styrene/acrylate rubber graft copolymer is preferable, and a methyl methacrylate/styrene/ethyl acrylate rubber graft copolymer is particularly preferable.

When core-shell rubber is used as the base material, the content of the core-shell rubber in the base is preferably 1% by mass or more, particularly preferably 3% by mass or more, and further preferably 5% by mass or more. is preferably Also, the content of the core-shell rubber in the substrate is preferably 50% by mass or less, particularly preferably 40% by mass or less, and further preferably 30% by mass or less. When the content of the core-shell rubber is within the above range, the semiconductor processing sheet easily satisfies the aforementioned ratio of elongation at break.

The substrate in this embodiment may contain various additives such as flame retardants, plasticizers, antistatic agents, lubricants, antioxidants, colorants, infrared absorbers, ultraviolet absorbers, and ion scavengers. Although the content of these additives is not particularly limited, it is preferably within a range in which the base material exhibits the desired functions.

The surface of the base material on which the semiconductor adhesion layer is to be laminated may be subjected to surface treatment such as primer treatment, corona treatment, plasma treatment, etc., in order to enhance adhesion with the semiconductor adhesion layer.

The thickness of the substrate in the present embodiment is preferably 40 μm or more, particularly preferably 50 μm or more, further preferably 60 μm or more. When the thickness of the base material is 40 μm or more, the strength of the base material becomes sufficient, and the work piece can be easily held on the sheet. Also, the thickness is preferably 300 μm or less, particularly preferably 200 μm or less, further preferably 150 μm or less. When the thickness of the base material is 300 μm or less, the base material can be stretched satisfactorily and easily during an expanding step or the like.

2. Semiconductor Attaching Layer The type of the semiconductor attaching layer in the present embodiment is not particularly limited as long as it can hold the workpiece when the semiconductor processing sheet according to the present embodiment is used to process the workpiece. . Preferred examples of the semiconductor sticking layer include an adhesive layer, a pressure-sensitive adhesive layer, a protective film-forming layer, and a laminate of two or more layers thereof.

When the semiconductor attachment layer is an adhesive layer, the semiconductor processing sheet according to the present embodiment can be used, for example, as a die bonding sheet. The material constituting the adhesive layer is not particularly limited as long as it can fix the wafer during dicing and form an adhesive layer on the individualized chips. can. As a material for forming such an adhesive layer, a material comprising a thermoplastic resin and a low-molecular-weight thermosetting adhesive component, a B-stage (semi-cured) thermosetting adhesive component, or the like is used. be done. Among these, it is preferable that the material constituting the adhesive layer contains a thermoplastic resin and a thermosetting adhesive component. Thermoplastic resins include (meth)acrylic copolymers, polyester resins, urethane resins, phenoxy resins, polybutene, polybutadiene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, and ethylene (meth)acrylic acid copolymers. Polymers, ethylene (meth)acrylic acid ester copolymers, polystyrene, polycarbonate, polyimide, etc. Among them, (meth)acrylic copolymers are preferred in terms of adhesiveness and film-forming properties (sheet processability). is preferred. Thermosetting adhesive components include epoxy-based resins, polyimide-based resins, phenol-based resins, silicone-based resins, cyanate-based resins, bismaleimide triazine-based resins, allylated polyphenylene ether-based resins (thermosetting PPE), and formaldehyde-based resins. , unsaturated polyesters, and copolymers thereof, among others, epoxy resins are preferred from the viewpoint of adhesiveness.

When the semiconductor attachment layer is an adhesive layer, the semiconductor processing sheet according to this embodiment can be used as, for example, a dicing sheet. The adhesive layer may be composed of a non-active energy ray-curable adhesive, or may be composed of an active energy ray-curable adhesive. As the non-active energy ray-curable adhesive, those having desired adhesive strength and removability are preferable, and examples include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives agents, polyvinyl ether-based adhesives, and the like can be used. Among these, an acrylic pressure-sensitive adhesive is preferable because it can effectively prevent a work piece, a chip, or the like from coming off in a dicing step or the like.

It is also preferable that the semiconductor sticking layer is a laminate comprising a pressure-sensitive adhesive layer and an adhesive layer. In this case, the adhesive layer is preferably located on the side proximal to the substrate and the adhesive layer is located on the side distal to the substrate. Such a semiconductor processing sheet according to this embodiment can be used, for example, as a dicing/die bonding sheet. As the adhesive constituting the adhesive layer, for example, those described above can be used. Further, as the adhesive constituting the adhesive layer, for example, those described above can be used.

It is also preferable that the semiconductor sticking layer is a laminate comprising an adhesive layer and a protective film-forming layer. In this case, the pressure-sensitive adhesive layer is preferably located on the proximal side of the substrate, and the protective film-forming layer is preferably located on the distal side of the substrate. Such a semiconductor processing sheet according to the present embodiment can be used for dicing a workpiece, and after dicing, a protective film can be formed on the obtained chip by heating the protective film forming layer. can be done. The protective film-forming layer is preferably made of an uncured curable adhesive. Moreover, it is preferable that the protective film-forming layer has adhesiveness at room temperature or exhibits adhesiveness upon heating. Examples of the curable adhesive that constitutes the protective film-forming layer having these properties include those containing a curable component and a binder polymer component.

The thickness of the semiconductor adhesion layer is preferably 3 μm or more, particularly preferably 5 μm or more, and further preferably 10 μm or more. Also, the thickness is preferably 40 μm or less, particularly preferably 30 μm or less, further preferably 20 μm or less. When the thickness of the semiconductor adhering layer is within these ranges, the semiconductor processing sheet easily exhibits desired performance in semiconductor processing.

3. Release Sheet In the semiconductor processing sheet according to the present embodiment, a release sheet is attached to the surface of the semiconductor attachment layer to which the workpiece is attached for the purpose of protecting the surface until the surface is attached to the workpiece. It may be laminated.

The configuration of the release sheet is arbitrary, and examples thereof include those obtained by releasing a resin film with a release agent or the like. Specific examples of resin films include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene.

As the release agent, a silicone-based release agent, a fluorine-based release agent, a long-chain alkyl-based release agent, or the like can be used.

Although the thickness of the release sheet is not particularly limited, it is usually 20 μm or more and 250 μm or less.

4. Method for Manufacturing Sheet for Semiconductor Processing The method for manufacturing the sheet for semiconductor processing according to the present embodiment is not particularly limited, and a general method can be used.

Examples of the method for producing the substrate include a melt extrusion method such as a T-die method and a round die method; a calender method; and a solution method such as a dry method and a wet method. Among these, in the case of producing by melt extrusion method, the material of the base material is kneaded, directly from the obtained kneaded product, or once pellets are produced, and then a known extruder may be used to form a film. .

When the semiconductor sticking layer consists of a pressure-sensitive adhesive layer or an adhesive layer, for example, by forming a semiconductor sticking layer on the release surface of a release sheet and pressing and laminating a substrate on the semiconductor sticking layer, A sheet for semiconductor processing can be produced.

In this case, the formation of the semiconductor adhesion layer on the release surface of the release sheet can be performed by a general method. First, a coating liquid is prepared which contains a composition containing a material for the pressure-sensitive adhesive layer or adhesive layer and, if desired, a solvent or dispersion medium. Subsequently, the coating solution is applied onto the release surface of the release sheet using a coating machine such as a roll coater, knife coater, roll knife coater, air knife coater, die coater, bar coater, gravure coater, curtain coater, or the like. , drying, etc., to form a semiconductor attachment layer.

When the semiconductor attachment layer is a laminate consisting of an adhesive layer and an adhesive layer, or a laminate consisting of an adhesive layer and a protective film-forming layer, first, the release sheet and the adhesive layer are separated by the method described above. A first laminate is obtained in which the substrates are laminated in order. In parallel with this, a coating liquid containing a composition containing a material for an adhesive layer or a protective film-forming layer and, optionally, a solvent or a dispersion medium is applied using the coating machine described above to peel off a release sheet. It is coated on the surface and dried to obtain a second laminate comprising a release sheet and an adhesive layer or a protective film forming layer. Next, the release sheet is peeled off from the first laminate, and the exposed adhesive layer side surface and the adhesive layer or protective film forming layer side surface of the second laminate are bonded together to form a semiconductor. A working sheet can be obtained.

5. Method of Using Semiconductor Processing Sheet The semiconductor processing sheet according to the present embodiment can be used for processing semiconductor materials. That is, after the surface of the semiconductor processing sheet according to the present embodiment on the side of the semiconductor bonding layer is attached to a workpiece (semiconductor material), the workpiece can be processed on the semiconductor processing sheet. Examples of workpieces (semiconductor materials) include semiconductor chips, semiconductor wafers, semiconductor packages, and the like. Examples of processing include back grinding, dicing, expanding, and picking up.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, another layer may be provided between the substrate and the semiconductor adhesion layer, or on the surface of the substrate opposite to the semiconductor adhesion layer.

EXAMPLES The present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Preparation Example 1] (Preparation of adhesive composition)
After obtaining an adhesive composition by mixing the following acrylic polymer, epoxy resin, curing agent / curing accelerator, filler, thermoplastic resin, photopolymerization initiator and silane coupling agent, the solid content concentration is 40 A coating liquid of the adhesive composition was prepared by mixing in methyl ethyl ketone so as to make the weight %.
<Acrylic polymer>
Obtained by copolymerizing 55 parts by mass of n-butyl acrylate (converted to solid content, hereinafter the same), 10 parts by mass of methyl acrylate, 18 parts by mass of glycidyl methacrylate and 17 parts by mass of 2-hydroxyethyl acrylate by a solution polymerization method. 100 parts by mass of an acrylic polymer (weight average molecular weight: 700,000) <epoxy resin>
150 parts by mass of triphenylene type epoxy resin (manufactured by Nippon Kayaku, product name “EPPN-502H”, epoxy equivalent: 167, softening point: 54 ° C., weight average molecular weight: 1200) Acrylic rubber fine particle dispersed epoxy resin (Nippon Shokubai Co., Ltd. Company, product name “Acryset BPA328”, epoxy equivalent: 235, liquid) 150 parts by mass <curing agent / curing accelerator>
140 parts by mass of novolac phenolic resin (manufactured by Showa Polymer Co., Ltd., product name “BRG-556”, hydroxyl equivalent: 104, softening point: 80 ° C.) 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Co., Ltd. , product name “Cure Sol 2PHZ-PW”) 2 parts by mass <filler>
Silica filler (manufactured by Admatechs, product name “Admafine SC2050MA”, surface modification: epoxy group modification, average particle size: 500 nm) 90 parts by mass <thermoplastic resin>
135 parts by mass of polyester resin (produced by Toyobo Co., Ltd., product name "Vylon 220", number average molecular weight: 3000, glass transition temperature: 53 ° C.) <UV-curable component>
35 parts by mass of tricyclodecanedimethylol diacrylate (manufactured by Nippon Kayaku, product name “KAYARAD R-684”, molecular weight: 304) <photopolymerization initiator>
1 part by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name “IRGACURE 184”) <Silane coupling agent>
4 parts by mass of a silicate compound to which 3-glycidoxypropyltrimethoxysilane was added (manufactured by Mitsubishi Chemical Corporation, product name “MSEP2”) Phenylaminopropyltrimethoxysilane (manufactured by Toray Industries, product name “DOWSIL Z-6883 Silane ”) to 1.5 parts by mass

[Preparation Example 2] (Preparation of adhesive composition)
95 parts by mass of n-butyl acrylate and 5 parts by mass of 2-hydroxyethyl acrylate were copolymerized by a solution polymerization method to obtain an acrylic polymer (weight average molecular weight: 800,000). 100 parts by mass of the acrylic polymer and 5 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Toyochem Co., Ltd., product name "BHS8515") as a cross-linking agent were mixed with acetic acid so that the solid content concentration was 30% by mass. By mixing in ethyl, a coating liquid of the adhesive composition was prepared.

[Example 1]
(1) Production of base material 52.5 parts by mass of low-density polyethylene, 22.5 parts by mass of high-density polyethylene, and 25 parts by mass of ethylene-propylene copolymer (mass ratio of ethylene monomer and propylene monomer is 10:90) was extruded using a small T-die extruder (manufactured by Toyo Seiki Seisakusho, product name: Laboplastomill) to obtain a substrate having a thickness of 80 µm.

(2) Formation of Adhesive Layer A first release sheet (manufactured by Lintec Corporation, product name "SP-PET381031", thickness: 38 μm) and a second release sheet (manufactured by Lintec Corporation, product name “SP-PET381130”, thickness: 38 μm), which is formed by forming a silicone-based release agent layer on one side of a 38 μm-thick PET film. and prepared.

Next, on the release surface of the first release sheet, the coating liquid of the adhesive composition prepared in Preparation Example 1 is applied using a knife coater, dried, and coated onto the release surface of the first release sheet. , to form an adhesive layer with a thickness of 5 μm. After that, the release surface of the second release sheet is superimposed on the adhesive layer and the two are laminated to form a laminate consisting of the first release sheet, the adhesive layer (thickness: 5 μm), and the second release sheet. got a body After that, the laminate was aged for 7 days in an environment with a temperature of 23° C. and a relative humidity of 50%.

(3) Fabrication of semiconductor processing sheet The second release sheet was peeled off from the laminate formed in step (2) to expose the adhesive layer. The exposed surface of this adhesive layer was attached to one surface of the substrate prepared in step (1) above. The laminate obtained by this lamination was stored for one week under an environment of 23° C. and 50%. As a result, a semiconductor processing sheet was obtained in which the release sheet, the adhesive layer as the semiconductor attachment layer, and the substrate were laminated in this order.

[Examples 2 to 4]
A semiconductor processing sheet was obtained in the same manner as in Example 1, except that the types and compounding ratios of the materials for the base material were changed as shown in Table 1.

[Example 5]
Preparation example using a comma coater on the release surface of a release sheet (manufactured by Lintec, product name "SP-PET3801") in which a silicone-based release agent layer is formed on one side of a PET film having a thickness of 38 μm. The coating liquid of the adhesive composition prepared in 2 was applied and dried at 90° C. for 1 minute to form an adhesive layer having a thickness of 10 μm on the release sheet. As a result, a laminate composed of an adhesive layer as a semiconductor adhesion layer and a release sheet was obtained.

On the other hand, 50 parts by mass of low-density polyethylene and 50 parts by mass of ethylene-propylene copolymer (mass ratio of ethylene and propylene is 10:90) were added to a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Lab Plastomill”) to obtain a substrate having a thickness of 80 μm.

After laminating the pressure-sensitive adhesive layer side surface of the laminate consisting of the pressure-sensitive adhesive layer and the release sheet obtained above to one side of the base material obtained as described above, the pressure-sensitive adhesive layer was placed under an environment of 23°C and 50%. was stored for 1 week. As a result, a semiconductor processing sheet was obtained in which the release sheet, the adhesive layer as the semiconductor attachment layer, and the substrate were laminated in this order.

[Example 6]
A laminate comprising the first release sheet, the adhesive layer and the second release sheet was obtained in the same manner as in step (2) of Example 1. The second release sheet was peeled off from the laminate to expose the adhesive layer.

On the other hand, in the same manner as in Example 5, a semiconductor processing sheet was obtained in which a release sheet, an adhesive layer, and a substrate were laminated in this order. The release sheet was peeled off from the semiconductor processing sheet to expose the adhesive layer.

Then, after the exposed surface of the adhesive layer described above and the exposed surface of the pressure-sensitive adhesive layer described above were bonded together, they were stored under an environment of 23° C. and 50% for one week. As a result, a semiconductor processing sheet as Example 6 was obtained in which the release sheet, the adhesive layer as the semiconductor attachment layer, the pressure-sensitive adhesive layer as the semiconductor attachment layer, and the substrate were laminated in this order.

[Comparative Examples 1 to 4]
A semiconductor processing sheet was obtained in the same manner as in Example 1, except that the types and compounding ratios of the materials for the base material were changed as shown in Table 1.

[Comparative Example 5]
Ethylene-methacrylic acid copolymer (EMAA) (manufactured by Mitsui DuPont Polychemicals, product name “Nucrel N0903HC”) is extruded using a small T-die extruder (manufactured by Toyo Seiki Seisakusho, product name “Laboplastomill”). to obtain an EMAA film with a thickness of 80 μm.

The resulting film is passed through an electron beam irradiation device (manufactured by ESI, product name “TYPE300/165/800”) at a speed of 45 m/min, and an electron beam is emitted from one main surface of the film. irradiated. The irradiation conditions were as follows.
Irradiation dose: 110 kGy
Irradiation time: 2.2 seconds Since the number of times of irradiation was one, the above-described irradiation dose and irradiation time correspond to the cumulative irradiation dose and cumulative irradiation time, respectively.

A semiconductor processing sheet was obtained in the same manner as in Example 1, except that the electron beam (EB)-irradiated EMAA film obtained as described above was used as a base material.

[Test Example 1] (Measurement of breaking elongation and breaking energy)
The semiconductor processing sheets produced in Examples and Comparative Examples were cut into a rectangular shape with a long side of 60 mm and a short side of 15 mm to obtain cut pieces. At this time, the long side of the cut piece was cut so as to be parallel to the MD direction of the base material (flow direction during manufacture of the base material).

Subsequently, in the cut piece, a notch was made at a position where it was divided into two in the long side direction (a position where two rectangles with a long side of 30 mm and a short side of 15 mm were formed). That is, an incision parallel to the short side was made at the center position of the long side of the cut piece. The incision was made from the surface on the release sheet side, and the depth of the incision was such that the remaining thickness of the base material was 40 μm. Then, a test piece was obtained by peeling and removing the release sheet.

For the obtained test piece, a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS 500N") was used in an environment of 23 ° C., the distance between chucks was set to 30 mm, and 1000 mm / A tensile test was performed by pulling the test piece in the long side direction at a speed of min, and the elongation at break (%) and the energy at break (N·mm) were measured. The results are shown in Table 1 as breaking elongation and breaking energy at 23°C.

Further, the test piece obtained in the same manner as described above was subjected to a tensile test in the same manner as described above in an environment of 50° C., and the breaking elongation (%) and breaking energy (N·mm) were measured. The results are also shown in Table 1 as breaking elongation and breaking energy at 50°C.

Furthermore, based on the breaking elongation and breaking energy measured as described above, the ratio of the breaking elongation at 50 ° C. and the breaking elongation at 23 ° C. (breaking elongation at 50 ° C./breaking elongation at 23 ° C.), And the ratio of the breaking energy at 50°C and the breaking energy at 23°C (breaking energy at 50°C/breaking energy at 23°C) was calculated. These results are also shown in Table 1.

[Test Example 2] (Measurement of the number of cut pieces)
The exposed surface of the semiconductor attachment layer (adhesive layer or pressure-sensitive adhesive layer) exposed by peeling the release sheet from the semiconductor processing sheets produced in Examples and Comparative Examples was peeled off from the semiconductor wafer (8 inches with a thickness of 40 μm is 1 /4) was pasted on one side. Then, the semiconductor wafer was diced under the following dicing conditions to separate into chips of 8 mm×8 mm.
<Dicing conditions>
・Dicing device: manufactured by Disco, product name “DFD-651”
・Blade: Disco, product name “27HEEE”
・Blade thickness: 0.020 to 0.025 mm
・Blade length: 0.510 to 0.640mm
・Blade speed: 30000rpm
・Cutting speed: 50 mm/sec ・Cutting depth: 20 μm to the base material
・Cutting water volume: 1.0 L/min ・Cutting water temperature: 20°C

The obtained semiconductor chip was removed from the semiconductor processing sheet, and the number of cut pieces adhering to the vicinity of the dicing line on the surface of the semiconductor chip attached to the semiconductor processing sheet was counted. At this time, the cut piece attached along the dicing line parallel to the MD direction of the base material, and the cut piece attached along the dicing line parallel to the direction perpendicular to the MD direction (CD direction) was measured separately. Moreover, the measurement was performed using a plurality of conductor chips until the total measured distance of the dicing lines in the MD and CD directions reached 40 cm. Table 1 shows the number of cut pieces in the MD direction, the number of cut pieces in the CD direction, and the total number of these pieces.

Details of abbreviations and the like in Table 1 are as follows.
LDPE: low density polyethylene HDPE: high density polyethylene PP-PE copolymer: ethylene-propylene copolymer (mass ratio of ethylene and propylene is 10:90)
PVC: Polyvinyl chloride Core-shell rubber: Methyl methacrylate/styrene/ethyl acrylate rubber graft copolymer (manufactured by Mitsubishi Chemical Corporation, product name “Metabrene W-300A”)
TPO: Olefin-based thermoplastic elastomer EMAA: Ethylene-methacrylic acid copolymer (manufactured by Mitsui DuPont Polychemicals, product name “Nucrel N0903HC”)

As can be seen from Table 1, the semiconductor processing sheets manufactured in Examples had a significantly smaller number of cut pieces than in Comparative Examples.

The semiconductor processing sheet of the present invention can be suitably used for processing semiconductor wafers and the like.

Claims (5)

A semiconductor processing sheet comprising a base material and a semiconductor attachment layer laminated on one side of the base material,
The semiconductor processing sheet was cut into a rectangle with a long side of 60 mm and a short side of 15 mm. A test piece with parallel cuts was subjected to a tensile test at 23 ° C. and 50 ° C. at a chuck distance of 30 mm and a tensile speed of 1000 mm / min. The breaking elongation measured under the following formula (1)
Breaking elongation at 50°C/breaking elongation at 23°C ≥ 3.0 (1)
A semiconductor processing sheet characterized by satisfying When the tensile test is performed on the test piece, the breaking energy measured under each environment of 23 ° C. and 50 ° C. is expressed by the following formula (2)
Breaking energy at 50°C/breaking energy at 23°C ≥ 2.0 (2)
2. The semiconductor processing sheet according to claim 1, wherein: 3. The semiconductor processing sheet according to claim 1, wherein the material of said base material contains at least one of polyolefin resin and polyvinyl chloride resin. The semiconductor processing sheet according to any one of claims 1 to 3, wherein the semiconductor attachment layer includes at least one layer of an adhesive layer, an adhesive layer and a protective film forming layer. 5. The semiconductor processing sheet according to claim 1, which is used for dicing.