Work processing sheet and processed work manufacturing method

Abstract

To provide a work processing sheet excellent in expandability and a processed work manufacturing method using the work processing sheet.SOLUTION: In a work processing sheet including a substrate and an adhesive layer laminated on one side of the substrate, when the static friction force on the side of the substrate opposite to the adhesive layer is 10 N or less, the tensile modulus of elasticity when the substrate is stretched by 1% in a tensile test at 23°C is E1, and the tensile modulus of elasticity when the substrate is stretched by 20% in a tensile test at 23°C is E20, the tensile modulus ratio calculated by E20 / E1 is 0.25 or more when the static friction force is 1 to 10 N, and is 0.03 or more when the static friction force is less than 1 N.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a workpiece processing sheet that can be used for processing workpieces such as semiconductor elements, and a method for manufacturing a processed workpiece.

Background Art

[0002] A method for manufacturing a semiconductor device generally includes a dicing step of dicing a semiconductor wafer on a dicing sheet to obtain a plurality of semiconductor chips, and a pickup step of individually picking up the obtained semiconductor chips from the dicing sheet.

[0003] In the above pickup step, in order to facilitate the pickup of semiconductor chips, the semiconductor chips may be individually pushed up from the surface of the dicing sheet opposite to the surface on which the semiconductor chips are stacked. In particular, in the above pickup step, in order to suppress the collision between semiconductor chips during pickup and facilitate pickup, the dicing sheet is usually expanded to separate the semiconductor chips from each other. Therefore, the dicing sheet is required to have excellent flexibility that enables good expansion.

[0004] Patent Document 1 discloses a dicing / diebond film premised on an expansion step, wherein the tensile strength at 25°C at the contact portion with the pushing-up jig of the dicing film is 15 N or more and 80 N or less, and the yield point elongation is 80% or more; the tensile strength at 25°C at the wafer bonding portion of the dicing film is 10 N or more and 70 N or less, and the yield point elongation is 30% or more; [(the tensile strength of the contact portion) - (the tensile strength of the wafer bonding portion)] is 0 N or more and 60 N or less; and the elongation at break rate at 25°C of the diebond film is greater than 40% and 500% or less.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2012-79936 Summary of the Invention Problems to be Solved by the Invention

[0006] However, the dicing / die-bonding film described in Patent Document 1 is for use in stealth dicing, and is intended to break the die-bonding film together with the wafer in the expansion process.

[0007] Here, depending on the type of semiconductor device, etc., semiconductor chips (workpieces) singulated on a dicing sheet may be transferred to a transfer sheet, and the transfer sheet may be expanded. And in some cases, after performing desired processing, such as heating or inspection, on the semiconductor chips in a state where the transfer sheet is expanded, and releasing the expansion, the semiconductor chips may be picked up from the transfer sheet. The dicing / die-bonding film described in Patent Document 1 is completely unsuitable for such applications.

[0008] The present invention has been made in view of such a situation, and an object thereof is to provide a workpiece processing sheet excellent in extensibility, and a method for manufacturing a processed workpiece using the workpiece processing sheet. Means for Solving the Problems

[0009] To achieve the above object, first, the present invention is a workpiece processing sheet including a base material and an adhesive layer laminated on one side of the base material, wherein the static frictional force of the surface of the base material opposite to the adhesive layer is 10 N or less, and the tensile elastic modulus when the base material is pulled by 1% in a tensile test at 23°C is E1, and the tensile elastic modulus when the base material is pulled by 20% in a tensile test at 23°C is E 20 When taken as 20Provided is a sheet for workpiece processing (Invention 1), characterized in that the tensile elastic modulus ratio calculated by / E1 is 0.25 or more when the static frictional force is 1 to 10 N, and 0.03 or more when the static frictional force is less than 1 N.

[0010] Due to having the above physical properties, the sheet for workpiece processing according to the above invention (Invention 1) exhibits excellent extensibility in the expansion process (especially the expansion process using a pushing jig).

[0011] In the above invention (Invention 1), it is preferable that the coefficient of kinetic friction of the surface of the base material on the side opposite to the adhesive layer is 0.05 or more and 3.00 or less (Invention 2).

[0012] In the above invention (Inventions 1 and 2), it is preferable that the surface roughness (Ra) of the surface of the base material on the side opposite to the adhesive layer is 0.10 μm or more and 5.00 μm or less (Invention 3).

[0013] In the above invention (Inventions 1 to 3), it is preferable that the elongation at break of the base material by a tensile test at 23°C is 500% or more and 1500% or less (Invention 4).

[0014] In the above invention (Inventions 1 to 4), it is preferable that the base material contains a thermoplastic elastomer (Invention 5).

[0015] In the above invention (Inventions 1 to 5), the base material may be composed of a single layer containing a thermoplastic elastomer (Invention 6), or may be composed of a plurality of layers including a layer containing a thermoplastic elastomer (Invention 7).

[0016] In the above invention (Inventions 1 to 7), it is preferably used for applications where a plurality of workpieces are expanded while being held by the adhesive layer and, after being released from the expanded state, the workpieces are picked up from the adhesive layer. (Invention 8).

[0017] Second, the present invention provides a method for manufacturing a processed work using the work processing sheet (Inventions 1 to 8), the method comprising: an expanding step of expanding the work processing sheet while holding a plurality of works with the adhesive layer; a processing step of performing a desired process on the works while the work processing sheet is in an expanded state; a releasing step of releasing the work processing sheet from the expanded state; and a picking-up step of picking up the processed works from the adhesive layer of the work processing sheet in the released state (Invention 9).

[0018] In the above invention (Invention 9), it is preferable to include a transferring step of transferring a plurality of works to the adhesive layer of the work processing sheet (Invention 10).

Advantages of the Invention

[0019] The work processing sheet according to the present invention is excellent in expandability. Further, according to the method for manufacturing a processed work of the present invention, a desired process can be performed on the work while the work processing sheet is well-expanded.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described. The work processing sheet according to an embodiment of the present invention includes a base material and an adhesive layer laminated on one side of the base material. In the work processing sheet according to this embodiment, the static frictional force of the surface of the base material on the side opposite to the adhesive layer is 10 N or less. Note that the "surface of the base material on the side opposite to the adhesive layer" is the surface that comes into contact with the pushing-up jig in the expanding step when the pushing-up jig is used. Further, in the work processing sheet according to this embodiment, when the tensile elastic modulus when the base material is stretched by 1% in a tensile test at 23°C is E1 and the tensile elastic modulus when the base material is stretched by 20% in a tensile test at 23°C is E 20 is set, E 20The tensile elastic modulus ratio calculated by / E1 is 0.25 or more when the static frictional force is 1 to 10 N, and 0.03 or more when the static frictional force is less than 1 N. The above tensile elastic modulus ratio (E 20 / E1) preferably satisfies for each of the MD direction (the flow direction during the production of the base material) and the CD direction (the direction perpendicular to the MD direction) of the base material. The static frictional force in this specification is measured in accordance with JIS K7125:1999, and specifically, it is measured by the method shown in the test example described later. Also, the tensile elastic modulus in this specification is measured by the tensile test shown in the test example described later.

[0021] Due to having the above physical properties, the sheet for workpiece processing according to this embodiment exhibits excellent expandability in the expansion process (especially the expansion process using a pushing jig). Therefore, in a state where the sheet for workpiece processing according to this embodiment is expanded, desired processing on the workpiece on the sheet for workpiece processing, such as heating and inspection, can be performed well. The reason for classifying according to the magnitude of the static frictional force as described above is that when the friction between the sheet for workpiece processing and the pushing jig is large, the sheet for workpiece processing is likely to be caught by the expanding device and the expansion rate tends to be inferior, and there is a different aspect from the case where the above friction is small. In addition, since the adhesive layer in the sheet for workpiece processing is very soft compared to the base material, the tensile physical properties of the sheet for workpiece processing are dominated by the tensile physical properties of the base material. Therefore, in the sheet for workpiece processing according to this embodiment, the tensile physical properties are defined by the tensile elastic modulus of the base material as described above, and this can be regarded as defining the sheet for workpiece processing.

[0022] In the work processing sheet according to this embodiment, the static friction force on the surface of the base material opposite to the adhesive layer is 10 N or less, preferably 8 N or less, and particularly preferably 4 N or less. Thereby, the expandability of the work processing sheet becomes more excellent. On the other hand, as a lower limit value, the static friction force is preferably 0.01 N or more, more preferably 0.1 N or more, and particularly preferably 0.4 N or more. Thereby, the occurrence of blocking and the like can be suppressed, and the handleability can be maintained well.

[0023] In the work processing sheet according to this embodiment, when the static friction force is 1 to 10 N, the tensile elastic modulus ratio (E 20 / E1) is 0.25 or more, preferably 0.255 or more. Thereby, the expandability of the work processing sheet becomes more excellent. On the other hand, as an upper limit value, the tensile elastic modulus ratio (E 20 / E1) is preferably 2 or less, and particularly preferably 0.5 or less. Thereby, the expandability of the work processing sheet becomes more excellent.

[0024] In the work processing sheet according to this embodiment, when the static friction force is less than 1 N, the tensile elastic modulus ratio (E 20 / E1) is 0.03 or more, preferably 0.035 or more. Thereby, the expandability of the work processing sheet becomes more excellent. On the other hand, as an upper limit value, the tensile elastic modulus ratio (E 20 / E1) is preferably 0.2 or less, and particularly preferably 0.18 or less. Thereby, the expandability of the work processing sheet becomes more excellent.

[0025] In the work processing sheet according to the present embodiment, the coefficient of kinetic friction of the surface of the base material on the side opposite to the adhesive layer is preferably 3.00 or less, more preferably 2.50 or less, and particularly preferably 2.00 or less. Thereby, the extensibility of the work processing sheet becomes more excellent. On the other hand, as the lower limit value, the coefficient of kinetic friction is preferably 0.05 or more, more preferably 0.10 or more, and particularly preferably 0.15 or more. Thereby, the occurrence of blocking or the like can be suppressed, and the handleability can be maintained favorably. The coefficient of kinetic friction in this specification is measured according to JIS K7125:1999, and specifically, it is measured by the method shown in the test example described later.

[0026] In the work processing sheet according to the present embodiment, the surface roughness (Ra) of the surface of the base material on the side opposite to the adhesive layer is preferably 0.10 μm or more, more preferably 0.30 μm or more, and particularly preferably 0.50 μm or more. Further, the surface roughness (Ra) is preferably 5.00 μm or less, more preferably 3.00 μm or less, and particularly preferably 2.00 μm or less. When the surface roughness (Ra) is within the above range, the static friction force and the coefficient of kinetic friction described above are likely to fall within the preferable ranges. The measurement method of the surface roughness (Ra) in this specification is as shown in the test example described later.

[0027] In the work processing sheet according to the present embodiment, the elongation at break of the base material by a tensile test at 23°C is preferably 500% or more, more preferably 550% or more, and particularly preferably 600% or more. Thereby, breakage of the sheet during the expansion process can be prevented. Further, the elongation at break is preferably 1500% or less, more preferably 1400% or less, and particularly preferably 1300% or less. Thereby, the work processing sheet can be expanded more favorably. The above elongation at break preferably satisfies for each of the MD direction and the CD direction of the base material.

[0028] 1. Configuration of the Sheet for Work Processing (1) Base Material The material constituting the base material of the sheet for work processing according to the present embodiment is not particularly limited as long as it satisfies the above-described physical properties (particularly physical properties by tensile test). From the viewpoint of easily achieving such physical properties, the base material in the present embodiment preferably contains a thermoplastic elastomer.

[0029] The base material in the present embodiment may be composed of a single layer or a plurality of layers. When the base material in the present embodiment is composed of a single layer, it is preferable that the single-layer base material contains a thermoplastic elastomer, and particularly preferably, the thermoplastic elastomer is the main component (a component occupying more than 50% of the whole). Further, when the base material in the present embodiment is composed of a plurality of layers, it is preferable that at least one layer, preferably more than half of the layers or a layer with more than half of the thickness, contains a thermoplastic elastomer, and particularly preferably, the thermoplastic elastomer is the main component. Thereby, it becomes easy for the base material to satisfy the above-described physical properties.

[0030] Examples of the thermoplastic elastomer include urethane-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, acrylic-based elastomers, amide-based elastomers, and the like. Among these, from the viewpoint of more easily achieving the above-described physical properties, it is preferable to use a urethane-based elastomer or a styrene-based elastomer.

[0031] Generally, a urethane-based elastomer is obtained by reacting a long-chain polyol, a diisocyanate, and a chain extender, and it consists of a soft segment having a structural unit derived from the long-chain polyol and a hard segment having a polyurethane structure obtained from the reaction of the diisocyanate and the chain extender.

[0032] When classifying urethane-based elastomers according to the type of long-chain polyol used as their soft segment component, they can be divided into polyester-based polyurethane elastomers, polyether-based polyurethane elastomers, polycarbonate-based polyurethane elastomers, and the like. In the sheet for workpiece processing according to this embodiment, among these, from the viewpoint of easily achieving the above-described physical properties, it is preferable to use a polyester-based polyurethane elastomer.

[0033] Examples of the above long-chain polyol include polyester polyols such as lactone-based polyester polyol and adipate-based polyester polyol; polyether polyols such as polypropylene (ethylene) polyol and polytetramethylene ether glycol; and polycarbonate polyol. Among these, from the viewpoint of easily achieving the above-described physical properties, it is preferable to use a polyester polyol.

[0034] Examples of the above diisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and hexamethylene diisocyanate. Among these, from the viewpoint of easily achieving the above-described physical properties, it is preferable to use hexamethylene diisocyanate.

[0035] Examples of the above chain extender include low molecular weight polyhydric alcohols such as 1,4-butanediol and 1,6-hexanediol, and aromatic diamines. Among these, from the viewpoint of easily achieving the above-described physical properties, it is preferable to use 1,6-hexanediol.

[0036] Examples of styrenic elastomers include styrene-conjugated diene copolymers and styrene-olefin copolymers, among which styrene-conjugated diene copolymers are preferred. Specific examples of styrene-conjugated diene copolymers include unhydrogenated styrene-conjugated diene copolymers such as styrene-butadiene copolymers, styrene-butadiene-styrene copolymers (SBS), styrene-butadiene-butylene-styrene copolymers, styrene-isoprene copolymers, styrene-isoprene-styrene copolymers (SIS), and styrene-ethylene-isoprene-styrene copolymers; hydrogenated styrene-conjugated diene copolymers such as styrene-ethylene / propylene-styrene copolymers (SEPS: hydrogenated product of styrene-isoprene-styrene copolymers) and styrene-ethylene-butylene-styrene copolymers (SEBS: hydrogenated product of styrene-butadiene copolymers). The styrenic elastomer may be a hydrogenated product (hydrogenated material) or an unhydrogenated material, but a hydrogenated product is preferred. Among the above, from the viewpoint of easily achieving the above-described physical properties, hydrogenated styrene-conjugated diene copolymers are preferred, and particularly styrene-ethylene-butylene-styrene copolymers (SEBS) are preferred.

[0037] When the base material in this embodiment is composed of a plurality of layers, the material constituting the layers other than the layer containing the thermoplastic elastomer is not particularly limited. As an example, a material that easily satisfies the above-described static frictional force (and coefficient of kinetic friction) and does not inhibit the tensile physical properties of the layer containing the thermoplastic elastomer is preferred. And it is preferable to dispose a layer made of such a material on the surface of the base material opposite to the adhesive layer (the surface in contact with the pushing jig).

[0038] Examples of the above materials include polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, norbornene resin and other polyolefin resins; polyester resins such as polyethylene terephthalate; ethylene copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer; polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; polystyrene; polyetherimide; polyetheretherketone; fluororesins and the like. Among the above, from the viewpoint of facilitating the base material to satisfy the above-described physical properties, polyolefin resins are preferred, and polyethylene is particularly preferred.

[0039] When the base material in this embodiment is composed of a plurality of layers, it is preferably composed of 2 to 5 layers, particularly preferably composed of 3 to 4 layers, and more preferably composed of 3 layers. When the base material is composed of 2 layers, both layers are preferably layers containing a thermoplastic elastomer, or one layer is a layer containing a thermoplastic elastomer, and the other layer, particularly the layer located on the surface opposite to the adhesive layer in the base material, is preferably a layer made of a polyolefin resin or the like. When the base material is composed of 3 layers, all 3 layers are preferably layers containing a thermoplastic elastomer, or the layer located on the surface opposite to the adhesive layer in the base material is a layer made of a polyolefin resin or the like, and the remaining 2 layers are preferably layers containing a thermoplastic elastomer. When there are a plurality of layers containing a thermoplastic elastomer in the base material, the thermoplastic elastomers may be of the same type or different types. In the case of the same type, the compositions may be the same or different. By having the above configuration, the base material is likely to satisfy the physical properties related to the above-described tensile properties and frictional force.

[0040] For the purpose of improving the adhesion to the adhesive layer, the surface of the substrate on which the adhesive layer is laminated may be subjected to surface treatment such as oxidation method or roughening method, or primer treatment. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, etc. Examples of the roughening method include sandblasting method, thermal spraying treatment method, etc.

[0041] The substrate in this embodiment may contain various additives such as fillers, lubricants, colorants, flame retardants, plasticizers, antistatic agents, fillers, etc. In particular, by containing a filler or a lubricant, it may be possible to easily satisfy the above-described static frictional force (and coefficient of dynamic friction). Also, for the same reason, the substrate in this embodiment may be provided with a lubricant coating layer on one side.

[0042] The filler may be an inorganic filler or an organic filler. The inorganic filler may be spherical or the like, or may be amorphous. Among them, a silica filler, particularly an amorphous silica filler, can be preferably used.

[0043] Examples of the lubricant include fatty acid-based lubricants, fatty acid amide-based lubricants, ester-based lubricants, polyethylene wax, liquid paraffin, etc. One kind may be used alone, or two or more kinds may be used in combination.

[0044] In addition, when the adhesive layer in this embodiment contains a material that is cured by active energy rays, the substrate preferably has permeability to active energy rays.

[0045] The method for manufacturing the base material in this embodiment is not particularly limited as long as a base material capable of achieving the above-described physical properties can be manufactured. For example, the base material can be manufactured by forming the above-described material into a sheet shape by a melt extrusion method such as a T-die method or a round-die method; a calendar method; a solution method such as a dry method or a wet method. In each manufacturing method, by controlling the surface shape (roughness) of a member with which the formed sheet comes into contact, such as a cooling roll, the surface roughness (Ra) of the obtained base material, and thus the static friction force and the coefficient of kinetic friction can be adjusted.

[0046] The thickness of the base material in this embodiment is preferably 10 μm or more, more preferably 20 μm or more, and particularly preferably 25 μm or more. Also, the thickness of the base material in this embodiment is preferably 300 μm or less, more preferably 200 μm or less, and particularly preferably 150 μm or less. When the thickness of the base material is within the above range, the above-described physical properties are likely to be satisfied, and excellent handleability can also be obtained.

[0047] (2) Adhesive layer The adhesive constituting the adhesive layer in this embodiment is not particularly limited as long as it can exhibit a desired adhesive force to an adherend (workpiece). Examples of the adhesive constituting the adhesive layer include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, and the like. Among these, from the viewpoint of easily exhibiting a desired adhesive force, it is preferable to use an acrylic adhesive.

[0048] The pressure-sensitive adhesive that constitutes the pressure-sensitive adhesive layer in this embodiment may be an active energy ray curable pressure-sensitive adhesive or an active energy ray non-curable pressure-sensitive adhesive, and may be appropriately selected according to the application. For example, when it is desired to greatly change the adhesive force depending on the application, it is preferable to use an active energy ray curable pressure-sensitive adhesive. In this case, the pressure-sensitive adhesive layer can be cured by irradiation with active energy rays, and the adhesive force of the work processing sheet to the adherend can be easily reduced. In particular, the processed work can be easily separated from the work processing sheet by irradiation with active energy rays. If the above requirements are not necessary, an active energy ray non-curable pressure-sensitive adhesive may be used.

[0049] The active energy ray non-curable acrylic pressure-sensitive adhesive is preferably a pressure-sensitive adhesive obtained by crosslinking a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer and a crosslinking agent. In this specification, (meth)acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. Also, the concept of "copolymer" is included in "polymer".

[0050] The (meth)acrylic acid ester polymer preferably contains a (meth)acrylic acid alkyl ester and a monomer containing a reactive functional group as monomer units constituting the polymer. Examples of the (meth)acrylic acid alkyl ester include (meth)acrylic acid methyl, (meth)acrylic acid ethyl, (meth)acrylic acid propyl, (meth)acrylic acid n-butyl, (meth)acrylic acid n-pentyl, (meth)acrylic acid n-hexyl, (meth)acrylic acid 2-ethylhexyl, etc., and (meth)acrylic acid alkyl esters having an alkyl group with 1 to 20 carbon atoms are preferably mentioned. Examples of the monomer containing a reactive functional group include a monomer containing a hydroxyl group, a monomer containing a carboxy group, a monomer containing an amino group, etc. These monomers may be used alone or in combination of two or more.

[0051] The crosslinking agent may be any one that reacts with the reactive functional groups of the (meth)acrylate polymer. Examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, and the like.

[0052] The thickness of the pressure-sensitive adhesive layer in the present embodiment may be appropriately set according to the application, but is usually preferably 1 to 100 μm, particularly preferably 5 to 50 μm, and more preferably 8 to 20 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, the sheet for workpiece processing according to the present embodiment is likely to exhibit a desired adhesiveness.

[0053] (3) Release sheet In the sheet for workpiece processing according to the present embodiment, a release sheet may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the base material (hereinafter sometimes referred to as the "adhesive surface") for the purpose of protecting the surface until it is attached to the workpiece.

[0054] The structure of the release sheet is arbitrary, and examples thereof include those obtained by subjecting a plastic film to a release treatment with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, etc. can be used, and among these, silicone-based which can obtain inexpensive and stable performance is preferable.

[0055] There is no particular limitation on the thickness of the release sheet, and for example, it may be 20 μm or more and 250 μm or less.

[0056] (4) Others In the work processing sheet according to this embodiment, an adhesive layer may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the base material. In this case, the work processing sheet according to this embodiment can be used, for example, as a dicing die bonding sheet. In this sheet, a work is attached to the surface of the adhesive layer opposite to the pressure-sensitive adhesive layer, and the adhesive layer is diced together with the work, whereby a chip with the fragmented adhesive layer laminated thereon can be obtained. This chip can be easily fixed to the object on which the chip is mounted by this fragmented adhesive layer. As the material constituting the above-described adhesive layer, it is preferable to use those containing a thermoplastic resin and a low molecular weight thermosetting adhesive component, those containing a B-stage (semi-cured state) thermosetting adhesive component, and the like.

[0057] Also, in the work processing sheet according to this embodiment, a protective film forming layer may be laminated on the adhesive surface of the pressure-sensitive adhesive layer. In this case, the work processing sheet according to this embodiment can be used, for example, as a protective film forming and dicing sheet. In such a sheet, a work is attached to the surface of the protective film forming layer opposite to the pressure-sensitive adhesive layer, and the protective film forming layer is diced together with the work, whereby a chip with the fragmented protective film forming layer laminated thereon can be obtained. As the work, it is preferable to use one having a circuit formed on one side. In this case, usually, the protective film forming layer is laminated on the surface opposite to the surface on which the circuit is formed. The fragmented protective film forming layer can be cured at a predetermined timing to form a protective film having sufficient durability on the chip. The protective film forming layer is preferably made of an uncured curable adhesive.

[0058] 2. Manufacturing method of work processing sheet The manufacturing method of the work processing sheet according to this embodiment is not particularly limited. For example, after forming a pressure-sensitive adhesive layer on a release sheet, it is preferable to obtain a work processing sheet by laminating one side of a base material on the surface of the pressure-sensitive adhesive layer opposite to the release sheet.

[0059] The formation of the above-described adhesive layer can be carried out by a known method. For example, an adhesive composition for forming the adhesive layer and, if desired, a coating solution further containing a solvent or a dispersion medium are prepared. Then, the coating solution is applied to the surface having peelability of the release sheet (hereinafter sometimes referred to as the "release surface"). Subsequently, the obtained coating film is dried to form an adhesive layer.

[0060] The application of the above-described coating solution can be carried out by a known method, for example, by a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc. The properties of the coating solution are not particularly limited as long as it can be applied, and it may contain components for forming the adhesive layer as a solute or as a dispersed substance. Further, the release sheet may be peeled as a process material, or may protect the adhesive layer until it is attached to the adherend.

[0061] When the adhesive composition for forming the adhesive layer contains the above-described crosslinking agent, by changing the above drying conditions (temperature, time, etc.) or by providing a separate heat treatment, the crosslinking reaction between the polymer component and the crosslinking agent in the coating film is advanced, and it is preferable to form a crosslinked structure with a desired density of existence in the adhesive layer. Further, in order to sufficiently advance the above-described crosslinking reaction, after bonding the adhesive layer and the base material, curing may be performed, for example, by leaving it standing in an environment of 23°C and a relative humidity of 50% for several days.

[0062] 3. Physical properties of the sheet for workpiece processing The sheet for workpiece processing according to the present embodiment preferably has an expansion ratio of 120% or more, particularly preferably 121% or more, and even more preferably 122% or more, obtained in the test example of the extensibility evaluation described later. By having the above-described physical properties, the sheet for workpiece processing according to the present embodiment can achieve a large expansion ratio as described above.

[0063] 4. Method of using the sheet for workpiece processing The work processing sheet according to this embodiment can be suitably used to perform desired processing on a plurality of works on the work processing sheet in a state where the work processing sheet is expanded. The processed work can be picked up from the work processing sheet in the expanded state or the work processing sheet after releasing the expanded state.

[0064] The work is preferably in a fragmented state, and may be fragmented by dicing or the like on the work processing sheet, or may be a work fragmented in another process transferred to the work processing sheet. Examples of the types of fragmented works include semiconductor elements, semiconductor chips, semiconductor packages, semiconductor members, glass members, etc., and also include LED elements, chip LEDs, etc. Examples of the work before fragmentation include semiconductor wafers, glass plates, etc.

[0065] The expansion of the work processing sheet is preferably performed using a known expander having a pushing jig, but is not limited thereto. This pushing jig contacts the surface of the base material of the work processing sheet opposite to the adhesive layer, and can expand (expand) the work processing sheet by pushing up the work processing sheet.

[0066] Examples of the desired processing include heat treatment, inspection, inspection under heating, and also include processes such as vapor deposition, sputtering, baking, etc. For example, in the case of inspection under heating, since the work processing sheet according to this embodiment can be sufficiently expanded, the distance between the works can be made relatively large, whereby the inspection of each work can be performed at a desired temperature.

[0067] The work processing sheet according to this embodiment can be used, for example, as a transfer sheet that also serves as an expand sheet and a pickup sheet, and can also be used as a dicing sheet, a dicing / die bonding sheet, a sheet for forming a protective film, etc.

[0068] 5. Method for manufacturing processed workpieces By using the workpiece processing sheet according to this embodiment, processed workpieces can be manufactured. The method for manufacturing processed workpieces according to an embodiment of the present invention includes an expanding step of expanding the workpiece processing sheet while holding a plurality of workpieces with an adhesive layer, a processing step of performing a desired process on the workpieces with the workpiece processing sheet in an expanded state, a releasing step of releasing the workpiece processing sheet from the expanded state, and a picking-up step of picking up the processed workpieces from the adhesive layer of the workpiece processing sheet in the released state. When holding a plurality of workpieces in the adhesive layer of the workpiece processing sheet, a transferring step of transferring the plurality of workpieces to the adhesive layer may be provided. Further, when holding a plurality of workpieces in the adhesive layer of the workpiece processing sheet, a dicing step of dicing the workpiece before singulation with the workpiece processing sheet may be provided.

[0069] The above-described transferring step, dicing step, expanding step, releasing step, and picking-up step can each be performed by a known method. The specific process in the processing step is not particularly limited, and for example, the above-described processes can be performed.

[0070] The embodiments described above are described for ease of understanding of the present invention and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[0071] For example, other layers may be provided on the side of the base material opposite to the adhesive layer or between the base material and the adhesive layer.

Example

[0072] Hereinafter, the present invention will be described more specifically by way of examples and the like, but the scope of the present invention is not limited to these examples and the like.

[0073] 〔Example 1〕 (1) Preparation of the Adhesive Composition 80 parts by mass of 2-ethylhexyl acrylate (2EHA) and 20 parts by mass of 2-hydroxyethyl acrylate (HEA) were polymerized by solution polymerization to obtain a (meth)acrylate polymer. When the weight average molecular weight (Mw) of this (meth)acrylate polymer was measured by the method described below, it was 800,000.

[0074] 100 parts by mass of the obtained (meth)acrylate polymer (in terms of solid content; the same applies hereinafter) and 5 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, product name "Coronate L") as a crosslinking agent were mixed in a solvent to obtain a coating solution of the adhesive composition.

[0075] (2) Formation of the Adhesive Layer The coating solution of the adhesive composition obtained in the above step (1) was applied to the release-treated surface of a release sheet (manufactured by Lintec Corporation, product name "SP-PET381031", thickness: 38 μm) whose one side of the polyethylene terephthalate film was release-treated with a silicone-based release agent, and the obtained coating film was dried at 100 °C for 1 minute. Thereby, a laminate was obtained in which an adhesive layer having a thickness of 10 μm was formed on the release surface of the release sheet.

[0076] (3) Production of the Substrate As the raw material resin, a polyester-based polyurethane elastomer (hardness (JIS-A): 90, density: 1.12 g / cm 3 ) which is a thermoplastic elastomer was prepared. The above thermoplastic elastomer (pellets) was supplied to an extruder with a diameter of 50 mm of a single-layer inflation film forming apparatus (manufactured by Tomii Kikai Kogyo Co., Ltd., product name "IF1000-55S-TWRJ") and melt-kneaded. Then, it was led to a single-layer die at a temperature of 205 °C and extruded to obtain a substrate made of a polyester-based polyurethane elastomer with a thickness of 30 μm.

[0077] (4) Production of the Sheet for Work Processing By bonding one side of the base material obtained in the above step (3) to the surface on the adhesive layer side of the laminate obtained in the above step (2), a sheet for workpiece processing was obtained. In the sheet for workpiece processing of Example 1, the tensile test described later was performed in the MD direction of the base material.

[0078] Here, the weight average molecular weight (Mw) described above is the weight average molecular weight in terms of standard polystyrene measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC). <Measurement conditions> · Measuring device: HLC-8320 manufactured by Tosoh Corporation · GPC column (passing in the following order): manufactured by Tosoh Corporation TSK gel superH-H TSK gel superHM-H TSK gel superH2000 · Measuring solvent: Tetrahydrofuran · Measuring temperature: 40 °C

[0079] [Example 2] (1) Production of base material In this example, a base material having a three-layer structure was produced. For this purpose, the following three types were prepared as raw resins. (a) Layer on the side in contact with the adhesive layer (first layer) Styrene-ethylene-butylene-styrene copolymer (SEBS) as a thermoplastic elastomer (b) Intermediate layer (second layer) Styrene-ethylene-butylene-styrene copolymer (SEBS) as a thermoplastic elastomer (c) Layer on the side opposite to the adhesive layer side (third layer) Polyethylene resin

[0080] Each of the above resins (pellets) was put into the hopper of a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., product name "TEM-50", 50φmm, L / D = 32), and the extruder temperatures were set as C1: 210°C, C2: 230°C, C3: 230°C, C4: 230°C, C5: 230°C, and co-extruded from a 550 mm wide T-die (temperature setting: 230°C, lip opening 0.3 mm). The extruded molten resin was cooled and solidified by a winder equipped with cooling rolls (cooling rolls: 700 mm wide × φ350 mm, roll temperature 30°C), and then a lubricant was applied to the surface of the third layer to obtain a substrate with a thickness of 100 μm. In this substrate, the thickness of the first layer was 2 μm, the thickness of the second layer was 90 μm, and the thickness of the third layer was 8 μm.

[0081] (2) Preparation of the sheet for workpiece treatment A sheet for workpiece treatment was obtained by bonding the surface on the first layer side of the substrate obtained in the above step (1) and the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the sheet for workpiece treatment of Example 2, the tensile test described below was performed in the CD direction of the substrate.

[0082] [Example 3] The sheet for workpiece treatment of Example 3 is the same as that of Example 2. However, in the sheet for workpiece treatment of Example 3, the tensile test described below was performed in the MD direction of the substrate.

[0083] [Example 4] The thickness of the second layer was changed to 92 μm and the thickness of the third layer was changed to 6 μm, and a substrate and a sheet for workpiece treatment were produced in the same manner as in Example 2 except that no lubricant was applied. In the sheet for workpiece treatment of Example 4, the tensile test described below was performed in the MD direction of the substrate.

[0084] [Example 5] A substrate and a sheet for workpiece treatment were produced in the same manner as in Example 2 except that no lubricant was applied. In the sheet for workpiece treatment of Example 5, the tensile test described below was performed in the MD direction of the substrate.

[0085] [Example 6] (1) Preparation of the base material As the raw material resin, a polyester-based polyurethane elastomer (hardness (JIS-A): 92, density: 1.24 g / cm 3 ) was used as a thermoplastic elastomer, and amorphous silica was prepared as a filler.

[0086] The above-mentioned thermoplastic elastomer (pellets) and filler were supplied to an extruder with a diameter of 100 mm of a single-layer inflation film-forming apparatus (manufactured by Tomii Kikai Kogyo Co., Ltd., product name "IF1000-55S-TWRJ") and melt-kneaded. Then, it was led to a single-layer die at a temperature of 205°C and extruded to obtain a base material made of a polyester-based polyurethane elastomer (containing amorphous silica) with a thickness of 100 μm.

[0087] (2) Preparation of the workpiece treatment sheet A workpiece treatment sheet was obtained by bonding one side of the base material obtained in the above step (1) to the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the workpiece treatment sheet of Example 6, the tensile test described below was performed in the MD direction of the base material.

[0088] 〔Example 7〕 (1) Preparation of the base material In this example, a base material with a three-layer structure was prepared. For this purpose, the following three types were prepared as raw material resins. In this example, the composition was the same for all three types. (a) Layer in contact with the adhesive layer (first layer) Styrene-ethylene-butylene-styrene copolymer (SEBS) as a thermoplastic elastomer (b) Intermediate layer (second layer) Styrene-ethylene-butylene-styrene copolymer (SEBS) as a thermoplastic elastomer (c) Layer on the side opposite to the adhesive layer side (third layer) Styrene-ethylene-butylene-styrene copolymer (SEBS) as a thermoplastic elastomer

[0089] Each of the above resins (pellets) was put into the hopper of a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., product name "TEM-50", 50φmm, L / D = 32), and the extruder temperatures were set as follows: C1: 210°C, C2: 230°C, C3: 230°C, C4: 230°C, C5: 230°C. Co-extrusion was carried out from a 550 mm wide T-die (temperature setting: 230°C, lip opening 0.3 mm). The extruded molten resin was cooled and solidified by a winder equipped with cooling rolls (cooling rolls: 700 mm wide × φ350 mm, roll temperature 30°C). Then, a lubricant was applied to the surface of the third layer to obtain a base material with a thickness of 145 μm. In this base material, the thickness of the first layer was 1 μm, the thickness of the second layer was 138 μm, and the thickness of the third layer was 6 μm.

[0090] (2) Preparation of the sheet for workpiece treatment A sheet for workpiece treatment was obtained by bonding the surface on the first layer side of the base material obtained in the above step (1) and the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the sheet for workpiece treatment of Example 7, the tensile test described below was carried out in the CD direction of the base material.

[0091] [Comparative Example 1] (1) Preparation of the base material As the raw material resin, a polyester-based polyurethane elastomer as a thermoplastic elastomer (hardness (JIS-A): 88, density: 1.12 g / cm 3 ) was prepared. The above thermoplastic elastomer (pellets) was supplied to an extruder with a diameter of 100 mm of a single-layer inflation film forming apparatus (manufactured by Tomii Kikai Kogyo Co., Ltd., product name "IF1000-55S-TWRJ") and melt-kneaded. Then, it was led to a single-layer die at a temperature of 205°C and extruded to obtain a base material made of a polyester-based polyurethane elastomer with a thickness of 100 μm.

[0092] (2) Preparation of the sheet for workpiece treatment A sheet for workpiece treatment was obtained by bonding one side of the base material obtained in the above step (1) and the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the sheet for workpiece treatment of Comparative Example 1, the tensile test described below was carried out in the MD direction of the base material.

[0093] [Comparative Example 2] A base material and a work processing sheet were produced in the same manner as in Example 7, except that the type of the cooling roll in the winder was changed. In the work processing sheet of Comparative Example 2, the tensile test described below was performed in the CD direction of the base material.

[0094] [Comparative Example 3] A base material and a work processing sheet were produced in the same manner as in Example 6, except that no filler was compounded. In the work processing sheet of Comparative Example 2, the tensile test described below was performed in the MD direction of the base material.

[0095] [Comparative Example 4] The work processing sheet of Comparative Example 4 is the same as the work processing sheet of Comparative Example 2. However, in the work processing sheet of Comparative Example 4, the tensile test described below was performed in the MD direction of the base material.

[0096] [Comparative Example 5] (1) Production of base material As a raw material resin, ethylene-methacrylic acid copolymer (EMAA) (manufactured by Mitsui DuPont Polychemicals Co., Ltd., product name "Nuclel N0903HC") was prepared. This EMAA was extrusion-molded by a small T-die extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Laboplast Mill") to obtain a base material made of EMAA with a thickness of 100 μm.

[0097] (2) Production of work processing sheet A work processing sheet was obtained by bonding one side of the base material obtained in the above step (1) and the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the work processing sheet of Comparative Example 5, the tensile test described below was performed in the MD direction of the base material.

[0098] [Comparative Example 6] (1) Production of base material As raw materials, polypropylene (PP; manufactured by Prime Polymer Co., Ltd., product name "Prime Polypro E100-GPL" (homo-PP)), polypropylene (PP; manufactured by Prime Polymer Co., Ltd., product name "Prime Polypro E222" (random-PP)), olefin thermoplastic elastomer (TPO; manufactured by Mitsui Chemicals, Inc., product name "Tafmer PN2070", PP:PE:Bu = 70:15:15), and an antistatic agent (AS agent; manufactured by Sanyo Chemical Industries, Ltd., product name "Pelestat") were prepared.

[0099] These were dry-blended so that the mass ratio was PP:TPO:AS agent = 80:15:5, and this was put into the apparatus used in Example 2, and extrusion molding was carried out in the same manner as in Example 2 to obtain a substrate (single layer) made of a polyolefin resin with a thickness of 100 μm.

[0100] (2) Preparation of a sheet for workpiece treatment A sheet for workpiece treatment was obtained by bonding one side of the substrate obtained in the above step (1) and the surface on the adhesive layer side of the laminate obtained in step (2) of Example 1. In the sheet for workpiece treatment of Comparative Example 6, the tensile test described later was carried out in the MD direction of the substrate.

[0101] [Test Example 1] (Measurement of surface roughness) The surface roughness (Ra) of the surface on the side where the adhesive layer was not laminated in the substrates prepared in the examples and comparative examples was measured in accordance with JIS B601:2001 using an optical interference microscope (manufactured by Veeco Instruments Inc., product name "Surface Profiler WYKO NT110"). At this time, the measurement conditions were PSI and a magnification of 50 times, and the average value of 5 measurement points was taken as the value of the surface roughness. The results are shown in Table 1.

[0102] [Test Example 2] (Friction measurement) The substrates prepared in the examples and comparative examples were placed on an aluminum plate with a surface roughness (Ra) of 0.11 μm. At this time, they were placed so that the surface of the substrate on the side where the adhesive layer was not laminated was in contact with the aluminum plate. A 200 g weight was fixed on the substrate, and the sheet for work treatment was moved at a tensile speed of 100 mm / min. Using a static and dynamic friction measuring machine (manufactured by Trinity Lab., product name "TriboMaster TL201Ts"), the static friction force (N) and the coefficient of dynamic friction were measured and calculated in accordance with JIS K7125:1999. The results are shown in Table 1.

[0103] 〔Test Example 3〕(Tensile Test) The substrates prepared in the examples and comparative examples were cut into a width of 15 mm × a length of 150 mm and used as test pieces. They were installed in a tensile and compression testing machine (manufactured by A&D Company, product name "Tensilon") so that the stretchable part of the test piece was 100 mm. Then, a tensile test was conducted at a temperature of 23°C and a tensile speed of 200 mm / min. The tensile elastic modulus E1 (MPa) when the substrate was stretched by 1% (1 mm) and the tensile elastic modulus E 20 (MPa) when the substrate was stretched by 20% (20 mm) were calculated respectively. Also, based on those results, the tensile elastic modulus E 20 was divided by the tensile elastic modulus E1 to calculate the tensile elastic modulus ratio (E 20 / E1). The respective results are shown in Table 1.

[0104] Also, in the above tensile test, the elongation at break (%) when the substrate broke was measured. The results are shown in Table 1.

[0105] 〔Test Example 4〕(Expandability Evaluation) The work processing sheets produced in the examples and comparative examples were pasted onto a 6-inch ring frame of an expander (manufactured by JCM Co., Ltd., product name "SE-100"), and a 2 cm square grid was drawn in the center of the work processing sheet. Then, a 6-inch stage, which is a pushing jig, was pushed up at a pushing height of 34 mm and a pushing speed of 5 mm / s to expand the work processing sheet. The length of each side (side length) of the grid after expansion was measured, and the expansion rate (%) was calculated from the following formula. The measurement was performed for each of the MD direction and CD direction of the base material of the work processing sheet, and the average value thereof was taken as the expansion rate (%). The results are shown in Table 1. Expansion rate (%) = {1 + (side length after expansion - side length before expansion) / side length before expansion} × 100

[0106] Also, based on the above expansion rate (%), the expandability was evaluated according to the following criteria. The results are shown in Table 1. 〇: The expansion rate was 120% or more. ×: The expansion rate was less than 120%.

[0107]

Table 1

[0108] As can be seen from Table 1, the work processing sheets produced in the examples were excellent in expandability.

Industrial Applicability

[0109] The work processing sheet according to the present invention is suitable for use in applications where, in a state where the work processing sheet is expanded, processes such as heating and inspection are performed on a plurality of works on the work processing sheet, and then the works are picked up.

Claims

A workpiece processing sheet comprising a base material composed of a single layer and an adhesive layer laminated on one side of the base material, wherein the static friction force of the surface of the base material on the side opposite to the adhesive layer is 10 N or less, Let E be the tensile elastic modulus when the base material is stretched by 1% in the tensile test at 23°C １ and let E be the tensile elastic modulus when the base material is stretched by 20% in the tensile test at 23°C ２０ When we have ２０ / E １ the calculated ratio of tensile elastic moduli is when the static friction force is 1 to 10 N, it is 0.25 or more, when the static friction force is less than 1 N, it is 0.03 or more A workpiece processing sheet characterized by the above. A workpiece processing sheet comprising a base material composed of multiple layers and an adhesive layer laminated on one side of the base material, wherein at least one layer of the multiple layers contains a urethane-based elastomer or a styrene-based elastomer, wherein the static friction force of the surface of the base material on the side opposite to the adhesive layer is 10 N or less, The tensile elastic modulus when the base material is stretched by 1% in the tensile test at 23°C is E １ The tensile elastic modulus when the base material is stretched by 20% in the tensile test at 23°C is E ２０ When it is set as ２０ / E １ The tensile elastic modulus ratio calculated by when the static friction force is 1 to 10 N, it is 0.25 or more, when the static friction force is less than 1 N, it is 0.03 or more A workpiece processing sheet characterized by the above.

3. The workpiece processing sheet according to claim 1 or 2, characterized in that the coefficient of kinetic friction of the surface of the base material on the side opposite to the adhesive layer is 0.05 or more and 3.00 or less.

4. The workpiece processing sheet according to any one of claims 1 to 3, characterized in that the surface roughness (Ra) of the surface of the base material on the side opposite to the adhesive layer is 0.10 μm or more and 5.00 μm or less.

5. The workpiece processing sheet according to any one of claims 1 to 4, characterized in that the elongation at break of the base material by a tensile test at 23 °C is 500% or more and 1500% or less.

6. The workpiece processing sheet according to claim 1, characterized in that the base material contains a thermoplastic elastomer.

7. The workpiece processing sheet according to any one of claims 1 to 6, characterized in that it is used for the purpose of expanding a plurality of workpieces while holding them with the adhesive layer and then picking up the workpieces from the adhesive layer after being released from the expanded state.

8. A method for manufacturing a processed workpiece using the workpiece processing sheet according to any one of claims 1 to 7, an expanding step of expanding the workpiece processing sheet while holding a plurality of workpieces with the adhesive layer, a processing step of performing a desired process on the workpiece while the workpiece processing sheet is in the expanded state, a releasing step of releasing the workpiece processing sheet from the expanded state A pickup step of picking up the processed work from the pressure-sensitive adhesive layer of the work processing sheet in the released state A method for manufacturing a processed work, characterized by comprising the above steps.

9. The method for manufacturing a processed work according to claim 8, further comprising a transfer step of transferring a plurality of works to the pressure-sensitive adhesive layer of the work processing sheet.

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