JP2012015341A - Separator-less type dicing tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator-less type dicing tape which is properly controlled in wind-off strength of a tape from an original sheet roll with preventing adherend thereof from being polluted by exfoliating agent derived from a back surface layer, and further reduced in environmental load and cost.SOLUTION: A separator-less type dicing tape 10 has a base material 1, an adhesive layer 2 which is formed on one surface of the base material 1 and formed of adhesive layer forming material containing adhesive agent, an ionization radiation curable compound and bridging agent, and a back surface layer 3 which is formed on the other surface of the base material and contains long-chain alkyl polymer type exfoliation agent. The back surface layer 3 is formed by coating the other surface of the base material 1 with back surface layer forming coating liquid containing the long-chain alkyl polymer type exfoliation agent of 4 to 10 wt.% in solid content concentration and drying the back surface layer forming coating liquid. The film thickness of the back surface layer 3 after drying is within the range of Ra+(0.2-1.8) μm in the arithmetic average roughness of the base material 1.

Description

  The present invention relates to a dicing tape used in a dicing process for cutting and separating electrical / electronic components such as a semiconductor wafer and a semiconductor package into small pieces, and relates to a separatorless dicing tape having no separator for protecting an adhesive layer.

  In general, in a process from a dicing process of a semiconductor wafer to a pickup process, an adhesive tape called a dicing tape is used for protecting and fixing the wafer. As the dicing tape, an ionizing radiation curable dicing tape having an adhesive layer containing an adhesive and an ionizing radiation curable compound that is polymerized and cured by ionizing radiation such as ultraviolet rays and electron beams is known. This ionizing radiation curable dicing tape is usually composed of a base material that is permeable to ionizing radiation, the pressure-sensitive adhesive layer, and a separator for protecting the pressure-sensitive adhesive layer (Patent Document). 1, 2, 3).

  However, since the separator included in the ionizing radiation curable dicing tape is a material that is peeled off and discarded at the time of use, the use of the separator increases the amount of resources used and the amount of waste generated, resulting in an environmental load and high cost. This is not preferable.

JP-A-60-196956 JP-A-7-86212 JP-A-6-49420

  However, the ionizing radiation curable dicing tape that does not use a separator has the following problems. In ionizing radiation curable dicing tape that does not use a separator, in order to protect the adhesive layer, it is necessary to store it in the state of a roll wound up until use, but in a configuration that does not have a separator The pressure-sensitive adhesive layer and the substrate are in direct contact with each other, the unwinding strength at the time of use is increased, and the workability is poor.

  When the present inventors have repeatedly studied in order to solve the above problems, the back layer made of a coating solution containing a specific release agent is formed on the side on which the adhesive layer of the substrate is formed. It was found that by forming on the opposite surface, the unwinding strength from the original fabric can be appropriately controlled even in a form having no separator. However, although the problem with the unwinding strength from the original fabric has been resolved, if the dicing tape is applied to the wafer and then peeled off, a release agent derived from the back layer will adhere to the wafer surface and contaminate the wafer. was there.

  Thus, the inventors further investigated and found that the cause of the wafer contamination was uneven application of the coating liquid containing a release agent generated when the back layer was formed on the substrate surface. It was. That is, when uneven coating occurs, a part of the release agent contained in the back layer moves to the pressure-sensitive adhesive layer at the time of unwinding, and adheres to the wafer as an adherend through the pressure-sensitive adhesive layer. it was thought.

  The present invention has been made in view of the above circumstances, and the object of the present invention is that the unwinding strength from the original fabric is appropriately controlled, and the adherend by the release agent derived from the back layer It is an object of the present invention to provide a separatorless dicing tape that can reduce environmental burden and cost.

  Specifically, the present invention provides the following.

  (1) A base material, a pressure-sensitive adhesive layer formed on one surface of the base material and made of a pressure-sensitive adhesive layer-forming material containing a pressure-sensitive adhesive, an ionizing radiation curable compound, and a crosslinking agent, and the other base material A back layer containing a long-chain alkyl polymer release agent, and the back layer contains the liquid long-chain alkyl polymer release agent in a solid content concentration of 4 to 10% by mass. The back surface layer-forming coating solution is applied to the other surface of the base material and dried, and the thickness of the back surface layer after drying is the arithmetic average roughness Ra + (0.2 to 1.8) Separatorless dicing tape characterized by being in the range of μm.

  (2) The separator-less dicing tape according to (1), wherein the substrate is made of unstretched polyethylene.

  (3) The separatorless dicing tape according to (1) or (2), wherein the ionizing radiation curable compound is an ultraviolet curable resin.

  (4) A separatorless dicing tape raw material obtained by winding the separatorless dicing tape according to any one of (1) to (3) in a roll shape with an adhesive layer as an inner side.

  (5) The separator-less dicing tape original fabric according to (4), wherein the unwinding strength is in the range of 0.01 to 0.6 N / 25 mm.

  According to the separator-less type dicing tape of the present invention, it is possible to reduce the amount of resources used and the amount of waste generated by omitting the separator to be peeled off and discarded in use. Since the diameter is reduced and the weight is reduced, it is possible to reduce the environmental load and the cost in each process of production and distribution. In addition, according to the separatorless dicing tape of the present invention, workability is good because the unwinding strength from the original fabric is appropriately controlled. Furthermore, according to the separatorless type dicing tape of the present invention, the adherend is not contaminated by the release agent derived from the back layer.

It is sectional drawing which shows one Embodiment of the separatorless type dicing tape of this invention. It is sectional drawing which shows one Embodiment of the separatorless type dicing tape original fabric of this invention.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. be able to.

  As shown in FIG. 1, a separatorless dicing tape 10 of the present invention is formed on a base material 1 and one surface of the base material 1 and contains a pressure sensitive adhesive, an ionizing radiation curable compound, and a crosslinking agent. The pressure-sensitive adhesive layer 2 made of a material for forming the agent layer, and the back layer 3 formed on the other surface of the substrate 1 and containing at least a long-chain alkyl polymer release agent, A back layer forming coating solution containing the liquid long-chain alkyl polymer release agent in a solid content concentration of 4 to 10% by mass is applied to the other surface of the substrate 1 and dried to form the back surface. The film thickness after drying of the layer 3 is in the range of the arithmetic average roughness Ra + (0.2 to 1.8) μm of the base material, and is a dicing tape having no separator. . According to the separator-less dicing tape of the present invention, it is possible to realize a reduction in resource usage and a reduction in dust by omitting a separator that is peeled off and discarded in use. Further, since the separator is omitted, the winding diameter when the dicing tape is made into a roll shape is reduced and the weight is reduced, so that it is possible to reduce the environmental load in each process of production and distribution. Hereinafter, it demonstrates in order of a base material, an adhesive layer, and a back layer.

[Base material]
In the separatorless type dicing tape of the present invention, the base material is not particularly limited as long as it has an elongation characteristic (expandability) necessary for the dicing tape and optical characteristics that do not hinder the transmission of ionizing radiation. Generally, a synthetic resin film is used. Examples of the material of the synthetic resin film include known resins such as polyolefin resins, polyester resins, polyvinyl chloride resins, polystyrene resins, polyurethane resins, (meth) acrylic resins, and fluorine resins. These can be used alone or in combination of two or more. When combining 2 or more types, it may be a copolymer resin mainly composed of these resins, a mixture, or a laminate composed of a plurality of layers. In the present invention, among the synthetic resins, polyolefin resins such as polypropylene and polyethylene having excellent permeability to ultraviolet rays are preferable, and unstretched polyethylene having a low density is particularly preferable. This is because unstretched polyethylene has the extensibility of 50% or more required as a dicing tape, and does not generate harmful gas during incineration, so there is no concern about environmental pollution. Furthermore, the unstretched polyethylene can reduce the weight of the tape.

  Although the thickness of a base material is not specifically limited, It is preferable that it is 20-300 micrometers, and it is more preferable that it is 50-200 micrometers. Within the above range, the mechanical strength is sufficient, warp and breakage are hardly caused, and an appropriate expandability is exhibited, so that workability is improved. In the dicing process, the surface of the silicon wafer can be well protected.

  In addition, in order to improve the wettability with an adhesive or a release agent, the substrate is subjected to corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, vapor deposition treatment, alkali treatment, etc. You may give a well-known easy-adhesion process or may form an easily-adhesive layer.

  The formation method of a base material is not specifically limited, For example, conventionally well-known film forming methods, such as a melt-extrusion method, a solution casting method, and a calendar method, can be used. In the case of a substrate made of unstretched polyethylene, a melt extrusion method such as an inflation method or a T-die method is preferably used. Moreover, you may use the commercially available base material previously formed into a film form by the said method.

[Adhesive layer]
In the separatorless dicing tape of the present invention, the pressure-sensitive adhesive layer is formed on one surface of the substrate and is made of a pressure-sensitive adhesive layer forming material containing a pressure-sensitive adhesive, an ionizing radiation curable compound, and a crosslinking agent.

(Adhesive)
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer forming material is not particularly limited as long as it has a desired pressure-sensitive adhesive force. For example, acrylic, urethane-based, rubber-based, silicone-based pressure-sensitive adhesives, etc. Among these, acrylic pressure-sensitive adhesives that are excellent in durability such as heat resistance and transparency and low in cost are preferable. Examples of the acrylic pressure-sensitive adhesive include an acrylic ester copolymer obtained by copolymerizing an acrylic ester and another monomer. Examples of the acrylate ester include ethyl acrylate, acrylate-n-butyl, acrylate-2-ethylhexyl, isooctyl acrylate, isononyl acrylate, hydroxylethyl acrylate, propylene glycol acrylate, acrylamide, glycidyl acrylate, and the like. These may be used alone or in combination of two or more.

  Examples of the other monomer include, for example, methyl acrylate, methyl methacrylate, styrene, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, itaconic acid, hydroxylethyl acrylate, hydroxylethyl methacrylate, propylene glycol acrylate, Examples include acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, n-ethylhexyl methacrylate, and the like. These may be used alone or in combination of two or more. Also good.

  The unit ratio of the acrylate ester contained in the acrylate copolymer and the other monomer (acrylate ester / other monomer) is not particularly limited as long as it exhibits a desired initial adhesive force. It is not limited and can be set as appropriate according to the purpose. In addition, the mass average molecular weight (Mw) of the acrylate copolymer is not particularly limited as long as it exhibits a desired initial adhesive force, but may be within a range of 10 to 1,500,000. Preferably, it is in the range of 20 to 1,000,000. If it is the said range, sufficient initial adhesive force can be exhibited, and it can be set as the adhesive layer of sufficient intensity | strength. In addition, the said mass mean molecular weight is a value of polystyrene conversion at the time of measuring by gel permeation chromatography (GPC).

(Ionizing radiation curable compound)
The ionizing radiation curable compound is not particularly limited as long as it is a compound that is cured by irradiation with ionizing radiation. For example, a photo radical polymerizable compound, a photo cationic polymerizable compound, a photo anion polymerizable compound, and a photodimerization property. Compounds and the like. Among these, a photoradical polymerizable compound is preferable. This is because the curing speed is high, and a wide variety of compounds can be selected. Furthermore, physical properties such as adhesiveness before curing and peelability after curing can be easily controlled to desired ones. . Examples of the photoradical polymerizable compound include monomers such as polyfunctional acrylates, polyfunctional methacrylates, urethane acrylates, urethane methacrylates, polyester acrylates, polyester methacrylates, and epoxy acrylates, oligomers, and the like. Among these, polyfunctional acrylate and polyfunctional methacrylate are preferable, and trimethylol methane triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol penta Unsaturated compounds containing three or more acryloyl groups in one molecule such as acrylate, pentaerythritol triacrylate, ethylene oxide or propylene oxide adduct thereof are more preferable. These have the function of curing the pressure-sensitive adhesive composition by three-dimensional crosslinking and reducing the adhesive strength when irradiated with ionizing radiation, and increasing the cohesive force of the pressure-sensitive adhesive so that it does not transfer to the adherend surface. It is because it has.

  Examples of the ionizing radiation include rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and γ rays, electron beams, proton rays, and neutron rays. In view of the curing speed, the availability of the irradiation device, the price, etc., curing by ultraviolet irradiation is preferable.

  The amount of the ionizing radiation curable compound contained in the pressure-sensitive adhesive layer forming material is preferably 1 to 80 parts by mass and more preferably 1 to 60 parts by mass with respect to 100 parts by mass of the pressure-sensitive adhesive. By adjusting the amount of the ionizing radiation curable compound, the adhesive strength after irradiation with ionizing radiation can be controlled. If the amount of the ionizing radiation curable compound is less than the lower limit of the above range, the crosslink density after irradiation with ionizing radiation is not sufficient, and proper peelability may not be realized. In addition, if the amount of ionizing radiation curable compound is greater than the upper limit of the above range, not only the adhesive strength at the time of adhering the adherend decreases, but the tack before irradiation with ionizing radiation significantly increases or the cohesive force increases. In some cases, the pressure-sensitive adhesive protrudes and contaminates the guide roll during production, or adhesive residue may be generated on the adherend.

(Crosslinking agent)
Although a crosslinking agent will not be specifically limited if it can bridge | crosslink with the said adhesive, An epoxy type crosslinking agent and an isocyanate type crosslinking agent are preferable. Examples of the isocyanate-based crosslinking agent include polyisocyanate compounds, trimers of polyisocyanate compounds, urethane prepolymers having terminal isocyanate groups obtained by reacting polyisocyanate compounds and polyol compounds, and such urethane prepolymers. These trimers can be used. The polyisocyanate compound is not particularly limited, and 2,4-tolylene diisocyanate, 2,5-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'- Examples thereof include diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, and lysine isocyanate.

  As the epoxy-based crosslinking agent, for example, a polyfunctional epoxy-based compound can be used. As polyfunctional epoxy-based compounds, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, Examples include 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutadiene diglycidyl ether.

  The amount of the crosslinking agent contained in the pressure-sensitive adhesive layer-forming material varies depending on the type of the crosslinking agent. For example, in the case of an isocyanate-based crosslinking agent, 0.01 to 10 mass with respect to 100 parts by mass of the pressure-sensitive adhesive. Part is preferable, and 0.2 to 10 parts by mass is more preferable. If it is the said range, the adhesiveness of an adhesive layer and a base material can be improved. If the amount of the isocyanate-based crosslinking agent is less than the lower limit of the above range, the adhesion between the pressure-sensitive adhesive layer and the substrate becomes insufficient, or it becomes difficult for the pressure-sensitive adhesive layer to have sufficient strength, and the wafer When peeling from an adherend such as the above, the pressure-sensitive adhesive layer may cause cohesive failure to cause adhesive residue. If the amount of the isocyanate-based crosslinking agent is larger than the upper limit of the above range, the adhesive strength is lowered and does not sufficiently adhere to the adherend, or remains as an unreacted monomer in the adhesive layer, and the cohesive strength is increased. It may decrease.

  Moreover, in the case of an epoxy type crosslinking agent, it is preferable that it is 0.05-10 mass parts with respect to 100 mass parts of adhesives, and it is more preferable that it is 0.1-10 mass parts. If it is the said range, the desired adhesive force and cohesion force before ionizing-radiation irradiation can be controlled. When the amount of the epoxy crosslinking agent is less than the lower limit of the above range, it becomes difficult for the pressure-sensitive adhesive layer to have sufficient strength, and the pressure-sensitive adhesive layer causes cohesive failure when peeled off from an adherend such as a wafer. , Glue residue may occur. If the amount of the epoxy-based crosslinking agent is larger than the upper limit of the above range, the adhesive force before irradiation with ionizing radiation is reduced, so that chip skipping may occur during dicing.

(Other ingredients)
When the ionizing radiation is a light beam, it is preferable that the pressure-sensitive adhesive layer forming material contains a photopolymerization initiator. According to the photopolymerization initiator, the sensitivity of the ionizing radiation curable compound is enhanced, so that the polymerization curing time by ionizing radiation and the ionizing radiation irradiation amount can be reduced. When the ionizing radiation curable compound is a photoradical polymerizable compound, the type of photopolymerization initiator is not particularly limited, and examples thereof include acetophenones, benzophenones, hydroxycyclohexyl phenyl ketone, Michler benzoyl benzoate. , Α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones and the like. These photopolymerization initiators may be used by mixing with a photosensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine. In addition, it is preferable that the quantity of the photoinitiator contained in the adhesive layer formation material is 1-3 mass parts with respect to 100 mass parts of adhesives. If the amount of the photopolymerization initiator is less than the lower limit of the above range, the polymerization initiation reaction is not sufficient, the adhesive strength after irradiation with ionizing radiation becomes excessively high, and there is a case where proper peelability cannot be realized. . When the amount of the photopolymerization initiator is larger than the upper limit of the above range, the ionizing radiation reaches only in the vicinity of the surface irradiated with ionizing radiation, and curing may be insufficient. In addition, the cohesive force is reduced, which may cause adhesive residue on the adherend.

  The pressure-sensitive adhesive layer-forming material may contain various additives such as an antistatic agent, an anti-aging agent, and a tackifier as needed, as long as the object of the present invention is not impaired.

The method for forming the pressure-sensitive adhesive layer is not particularly limited. For example, the pressure-sensitive adhesive layer forming material for the pressure-sensitive adhesive layer such as the pressure-sensitive adhesive, ionizing radiation curable compound, or crosslinking agent is diluted with a suitable solvent, and the pressure-sensitive adhesive layer Examples thereof include a method in which after forming a forming coating solution, the pressure-sensitive adhesive layer forming coating solution is applied to a substrate by printing or coating, and dried. Examples of the forming method by printing include a gravure printing method, a flexographic printing method, and an offset printing method. Examples of the coating method include roll coating, reverse coating, comma coating, knife coating, die coating, and gravure coating. The solvent to be diluted is not particularly limited as long as it can dissolve or disperse the pressure-sensitive adhesive layer forming material. For example, toluene, methyl ethyl ketone and the like are preferable. Moreover, it is preferable that the application quantity of the coating liquid for adhesive layer formation is 10-300 g / m < ² >. If the coating amount is less than the lower limit of the above range, sufficient adhesive strength may not be obtained. If the coating amount is larger than the upper limit of the above range, excessive performance may be caused and the cost may be increased. In addition, it is preferable to adjust so that the film thickness of the adhesive layer after drying may be set to 5-50 micrometers, and it is more preferable to adjust so that it may be set to 5-20 micrometers.

[Back layer]
In the separatorless dicing tape of the present invention, the back layer is formed on the surface opposite to the surface on which the pressure-sensitive adhesive layer of the substrate is formed, and contains a long-chain alkyl polymer release agent. The back layer is coated with a back layer forming coating solution containing 4 to 10% by mass of the solid long-chain alkyl polymer release agent on the other surface of the substrate and dried. The film thickness of the back layer formed and dried is in the range of arithmetic average roughness Ra + (0.2 to 1.8) μm of the substrate. According to the dicing tape of this invention which has such a back layer, even if it is a form which does not have a separator, the unwinding intensity | strength from an original fabric shows an appropriate value. Moreover, the application | coating nonuniformity of the coating liquid for back layer formation does not arise. When uneven coating occurs, a part of the release agent contained in the release layer moves to the adhesive layer when unrolling from the original fabric, and adheres to the adherend through the adhesive layer. According to the dicing tape of the present invention on which the back layer is formed, coating unevenness does not occur, so that the adherend is not contaminated.

(paint remover)
The back layer contains a long-chain alkyl polymer release agent. The long-chain alkyl polymer release agent does not generate harmful gas at the time of disposal, has little impact on the environment, and does not easily cause contamination to electric / electronic parts. In the present invention, long-chain alkyl refers to those having 12 to 40 carbon atoms, preferably those having 12 to 30 carbon atoms. In addition, in this invention, it is preferable to contain the alkyl pendant polymer in which the C12-C30 long-chain alkyl introduced into the main chain polymer exists as a side chain in a pendant form.

  The mass average molecular weight (Mw) of the long-chain alkyl polymer used in the present invention is not particularly limited, but is preferably 10,000 to 500,000, and more preferably 100,000 to 300,000. If it is in the said range, appropriate peeling performance can be maintained. When the mass average molecular weight exceeds 500,000, the solubility in a solvent may decrease. On the other hand, if the mass average molecular weight is less than 10,000, it may move to the pressure-sensitive adhesive layer and inhibit the properties of the pressure-sensitive adhesive. In addition, the said mass mean molecular weight is a value of polystyrene conversion at the time of measuring by gel permeation chromatography (GPC).

  The back layer is formed by applying a coating solution for forming a back layer containing the liquid long-chain alkyl polymer release agent to the other surface of the substrate and drying it. Here, the liquid state means a state showing fluidity at room temperature (25 ° C.). If the property of the long-chain alkyl polymer release agent is powder, the release agent is likely to precipitate in the back layer forming step, and coating unevenness is likely to occur. However, according to the liquid release agent having a high affinity for the solvent, the release agent is unlikely to precipitate in the back layer forming step, and coating unevenness is less likely to occur.

  The method for forming the back layer is not particularly limited. For example, after the release agent is diluted with an appropriate solvent to prepare a back layer forming coating solution, the back layer forming coating solution is printed. For example, a method of forming the film by applying it to a base material by coating or coating, and drying it. The back layer is preferably formed on the untreated corona surface of the substrate. Examples of the forming method by printing include a gravure printing method, a flexographic printing method, and an offset printing method. Examples of the coating method include roll coating, reverse coating, comma coating, knife coating, die coating, and gravure coating. Although the solvent to dilute will not be specifically limited if the said release agent can be disperse | distributed or dissolved, For example, toluene, methyl ethyl ketone, etc. are preferable. The blending ratio of the release agent and the solvent in the coating solution for forming the back layer is adjusted so that the solid content concentration of the release agent is 4 to 10%, more preferably the solid content concentration of the release agent is 5 to 10%. Adjust so that When the solid content concentration of the release agent is within the above range, coating unevenness and stickiness at the time of winding are less likely to occur, so that good release performance is exhibited and the unwinding strength becomes appropriate. In addition, if the solid content concentration of the release agent is less than the lower limit of the above range, the viscosity of the back surface layer forming coating solution becomes low, the thickness of the back surface layer becomes uneven, and good release performance may not be exhibited. is there. Moreover, since the release agent concentration in the back layer is low, sufficient release performance may not be exhibited. Furthermore, since the relative proportion of the solvent increases, it takes time to dry after coating, and stickiness tends to occur during winding. If the solid content concentration of the release agent is higher than the upper limit of the above range, the viscosity of the back layer forming coating liquid will increase, making it difficult to form a back layer with a uniform thickness and exhibiting good release performance. May not be.

  The back layer has a thickness after drying in the range of the arithmetic average roughness Ra + (0.2 to 1.8) μm of the base material, and the arithmetic average roughness Ra + (0.3 to 1 of the base material). .5) It is preferably within the range of μm. If it is in the said range, appropriate peeling performance will be exhibited. In addition, since coating unevenness does not occur, contamination of the adherend as described above does not occur. In addition, when the film thickness after drying is thicker than the upper limit of the said range, it will become excess performance and may become high cost. The arithmetic average roughness (Ra) of the surface of the substrate was measured by a method according to JIS B0601-2001 using a surface roughness measuring instrument (measurement range: 1.0 mm × 1.0 mm, measurement speed: 0.6 mm / s). As the surface roughness measuring instrument, for example, Surfcom 1400D-3DF manufactured by Tokyo Seimitsu Co., Ltd. can be used.

  In the back layer, various additives such as an antistatic agent and an anti-aging agent may be blended as necessary within the range not impairing the object of the present invention.

[Method for manufacturing separatorless dicing tape]
The separatorless dicing tape of the present invention can be produced by forming a pressure-sensitive adhesive layer on one side of a substrate and forming a back layer on the other side of the substrate. The manufacturing method of a base material, the formation method of an adhesive layer, and the formation method of a back layer are as having mentioned above. In addition, the order which forms an adhesive layer and a back surface layer in a base material surface is not specifically limited, It can select arbitrarily.

[Separator-less dicing tape stock]
As shown in FIG. 2, the separator-less dicing tape original fabric 20 of the present invention is obtained by winding the separator-less dicing tape manufactured by the above method into a roll shape with the pressure-sensitive adhesive layer 2 inside. By winding in this way, the pressure-sensitive adhesive layer 2 can be protected from the outside air. The unwinding strength when unwinding the separatorless dicing tape from the separatorless dicing tape original fabric is preferably within a range of 0.01 to 0.6 N / 25 mm, and 0.01 to 0.4 N / More preferably within the range of 25 mm. This is because unwinding defects are less likely to occur within the above range.

  The unwinding strength is determined by dicing tape (back layer / base material / adhesive layer / back layer / base material / double layer of 25 mm width × 150 mm length) from the separatorless dicing tape original fabric. A test piece is prepared by cutting out the pressure-sensitive adhesive layer, and one dicing tape of the test piece is peeled from the other dicing tape in the length direction of the test piece (peeling speed: 300 mm / min, peel angle: 180 °). Can be measured. A universal material testing machine (model 5565, manufactured by Instron Japan) can be used as the measuring apparatus.

  The method of winding the separatorless dicing tape can be the same as that of a conventionally known adhesive tape except that there is no separator, but taking into account the feature that there is no separator, the air at the time of winding It is preferable to use a touch roll that is highly flexible and capable of applying a high load. Moreover, it is preferable to carry out by Roll to Roll from supply of a base material to manufacture of a separatorless type dicing tape original fabric. Here, “Roll to Roll” means that the base material is unwound from the base material roll in a roll shape, processed and processed without cutting the base material, and a separatorless dicing tape is manufactured. The separatorless type dicing tape is wound into a roll to form a raw material. Furthermore, it is preferable to carry out under a clean environment from the application of the coating solution for forming the adhesive layer and the coating solution for forming the back layer to the substrate to winding up the separatorless dicing tape. In addition, it is preferable that the separatorless type dicing tape wound up is subjected to aging in order to improve the adhesion between the base material and the pressure-sensitive adhesive layer. Although the aging conditions differ depending on the pressure-sensitive adhesive layer forming material, for example, it may be performed at 15 to 80 ° C. for 15 to 168 hours.

[How to use separatorless dicing tape]
The separatorless dicing tape of the present invention is used for fixing a workpiece in a dicing process in the manufacture of semiconductor parts, optical parts, electronic parts, etc., and as a pasting object, silicon wafer, glass, ceramic, etc. Is mentioned. The separatorless dicing tape unwound from the original fabric is affixed to a silicon wafer or the like. However, the separatorless dicing tape of the present invention does not have a separator to be separated and discarded, and therefore no dust is generated. Further, since there is no separator, the roll diameter of the original fabric is smaller than that of the conventional product and the weight becomes light. Therefore, the efficiency of transportation and work is increased, and the environmental load in the manufacturing process can be reduced.

  The separatorless type dicing tape of the present invention affixed to a silicon wafer or the like is irradiated with ionizing radiation from the back layer side after the dicing step to cure the ionizing radiation curable compound contained in the adhesive layer, The adhesive strength of the portion attached to a silicon wafer or the like is reduced to enable pickup. Therefore, it is preferable that the base material and the back layer have excellent transparency to ionizing radiation. For example, when the ionizing radiation is light, the light transmittance of 400 nm or less of the base material and the back layer is 80% or more. Is preferred. The light transmittance can be measured using a commercially available spectrophotometer, for example, MPC2200 manufactured by Shimadzu Corporation.

When ultraviolet rays are used as the ionizing radiation, for example, a high-pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, etc. Irradiation may be performed so as to be 10 mJ / cm ² or more, preferably 50 mJ / cm ² or more.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention does not receive a restriction | limiting at all by these description.

<Example 1>
Using an inflation extruder, 100 parts by mass of low density polyethylene film (trade name: Sumikasen F200, density: 0.924 g / cm ³ , MFR: 2 g / min (measured at 190 ° C., load 2160 g) manufactured by Sumitomo Chemical Co., Ltd.) And extruded to form a single layer film having a thickness of 100 μm. One side of this monolayer film was corona treated to obtain a substrate. In addition, the arithmetic mean roughness (Ra) of the corona-untreated surface of this base material was measured according to JIS B0601-2001 (measuring device: Surfcom 1400D-3DF manufactured by Tokyo Seimitsu Co., Ltd., measuring range: 1.0 mm × 1. 0 mm, measuring speed: 0.6 mm / s), it was 0.13 μm.

Next, 100 parts by mass of a release agent (long-chain alkyl pendant polymer, trade name: Pyroyl 1050, property: liquid, mass average molecular weight: 100,000, manufactured by Yushi Kogyo Co., Ltd.) is diluted with 100 parts by mass of toluene, and fully Dispersed to prepare a coating solution for forming a back layer (solid content concentration of release agent: 5%). This back layer forming coating solution was applied on the entire surface of the base material on the corona-untreated surface by a gravure coating method so that the film thickness after drying was 0.5 μm, dried with hot air, A layer was formed.
Next, on the corona-treated surface of the base material, an adhesive layer forming coating solution having the composition shown in Table 1 is applied over the entire surface by a die coating method so that the film thickness after drying is 10 μm, followed by hot air drying. Thus, a pressure-sensitive adhesive layer was formed to obtain a separatorless dicing tape (back layer (0.5 μm) / base material (100 μm) / pressure-sensitive adhesive layer (10 μm)). After slitting the separatorless dicing tape to a width of 300 mm, the separator layer was wound into 100 m in a roll shape with the adhesive layer inside, and aged at 40 ° C. for 72 hours to prepare a separatorless dicing tape original. The separator-less dicing tape original fabric was produced in one step in-line using a single coating apparatus.

<Example 2>
Separatorless dicing tape (back surface layer (0.5 μm) / base material (150 μm) / adhesive layer (10 μm)) and its method in the same manner as in Example 1 except that the thickness of the base material was 150 μm I got the original fabric.

<Example 3>
Example except that 100 parts by mass of the release agent was diluted with 42.9 parts by mass of toluene and sufficiently dispersed to prepare a coating solution for forming the back layer (solid content concentration of the release agent: 7%). 1 was used to obtain a separatorless dicing tape (back layer (0.5 μm) / base material (100 μm) / adhesive layer (10 μm)) and its original fabric.

<Example 4>
Example except that 100 parts by mass of the release agent was diluted with 42.9 parts by mass of toluene and sufficiently dispersed to prepare a coating solution for forming the back layer (solid content concentration of the release agent: 7%). 2 was used to obtain a separatorless dicing tape (back layer (0.5 μm) / base material (150 μm) / adhesive layer (10 μm)) and its original fabric.

<Example 5>
Separatorless dicing tape (back layer (0.5 μm) / base material (100 μm) / adhesive) in the same manner as in Example 1 except that the coating solution for forming the adhesive layer shown in Table 2 was used. Agent layer (10 μm)) and its original fabric.

<Example 6>
Separatorless dicing tape (back surface layer (0.5 μm) / base material (150 μm) / adhesive layer (10 μm)) and its method in the same manner as in Example 5 except that the thickness of the base material was 150 μm I got the original fabric.

<Example 7>
Example except that 100 parts by mass of the release agent was diluted with 42.9 parts by mass of toluene and sufficiently dispersed to prepare a coating solution for forming the back layer (solid content concentration of the release agent: 7%). 5 was used to obtain a separatorless dicing tape (back layer (0.5 μm) / base material (100 μm) / adhesive layer (10 μm)) and its original fabric.

<Example 8>
Example except that 100 parts by mass of the release agent was diluted with 42.9 parts by mass of toluene and sufficiently dispersed to prepare a coating solution for forming the back layer (solid content concentration of the release agent: 7%). 6 was used to obtain a separatorless dicing tape (back layer (0.5 μm) / base material (150 μm) / adhesive layer (10 μm)) and its original fabric.

<Example 9>
Separatorless dicing tape (back layer (1.7 μm)) in the same manner as in Example 1 except that the coating solution for forming the back layer was adjusted so that the film thickness after drying was 1.7 μm. / Substrate (150 μm) / Adhesive layer (10 μm)) and its original fabric.

<Comparative Example 1>
Separatorless dicing tape (back layer (0.1 μm)) in the same manner as in Example 1 except that the coating solution for forming the back layer was adjusted so that the film thickness after drying was 0.1 μm. / Substrate (100 μm) / Adhesive layer (10 μm)) and the original fabric.

<Comparative example 2>
Separatorless dicing tape (back layer (0.3 μm)) in the same manner as in Example 1 except that the coating solution for forming the back layer was adjusted so that the film thickness after drying was 0.3 μm. / Substrate (100 μm) / Adhesive layer (10 μm)) and the original fabric.

<Comparative Example 3>
3 parts by weight of release agent (long-chain alkyl pendant polymer, trade name: Pyroyl 1010, property: powder, manufactured by Yushi Kogyo Co., Ltd.) is diluted with 97 parts by mass of toluene and dispersed sufficiently to form a back layer. A separatorless dicing tape (back layer (0.3 μm) / base material (100 μm) / in the same manner as in Example 1 except that the coating liquid (solid content concentration of release agent: 3%) was prepared) A pressure-sensitive adhesive layer (10 μm)) and its original fabric were obtained.

<Comparative example 4>
100 parts by mass of the release agent is diluted with 900 parts by mass of toluene and sufficiently dispersed to prepare a back layer forming coating solution (solid content concentration of the release agent: 1%), and the back layer forming coating Separatorless dicing tape (back layer (0.1 μm) / base material (100 μm)) in the same manner as in Example 1 except that the film thickness after drying was adjusted to 0.1 μm. / Adhesive layer (10 μm)) and its original fabric.

<Comparative Example 5>
100 parts by mass of the release agent is diluted with 233 parts by mass of toluene and sufficiently dispersed to prepare a back layer forming coating solution (solid content concentration of the release agent: 3%), and the back layer forming coating Separatorless dicing tape (back layer (0.3 μm) / base material (100 μm)) in the same manner as in Example 1 except that the film thickness after drying was adjusted to 0.3 μm. / Adhesive layer (10 μm)) and its original fabric.

[Confirmation of coating unevenness of coating liquid for back layer formation]
The presence or absence of coating unevenness of the coating solution for forming the back layer in the back layer of the dicing tape obtained in Examples 1 to 9 and Comparative Examples 1 to 5 was visually confirmed. The case where coating unevenness was not recognized was evaluated as ◯, the case where it was slightly recognized was evaluated as Δ, and the case where it was clearly recognized was evaluated as ×. The results are shown in Table 3.

[Confirmation of remaining release agent]
From the dicing tape original fabrics obtained in Examples 1 to 9 and Comparative Examples 1 to 5, a dicing tape having a width of 25 mm and a length of 100 mm was cut out to prepare a test piece.
The pressure-sensitive adhesive layer surface of the test piece was bonded to a silicon wafer using a 2 kg roller, and left for 20 minutes at room temperature and humidity. Next, after irradiating the substrate with ultraviolet rays using H / bulb lamp manufactured by Fusion as a light source (integrated light quantity: 200 mj / cm ² ), the test piece was peeled off (peeling speed: 300 mm / min, peeling distance: 50 mm, Peeling angle: 180 °) and the remaining release agent on the silicon wafer was confirmed with an optical microscope (VHX-600, manufactured by Keyence Corporation, magnification: 200). The results are shown in Table 3.

[Evaluation of unwinding strength]
Dicing tape (back layer / base material / adhesive layer) in a state where two layers of width 25 mm × length 150 mm are overlapped from the original dicing tape obtained in Examples 1 to 9 and Comparative Examples 1 to 5 / Back layer / Substrate / Adhesive layer) was cut out to prepare a test piece. The unwinding strength was measured (peeling speed: 300 mm / min, peel angle: 180 °) by peeling one dicing tape of this test piece from the other dicing tape in the length direction of the test piece. A universal material testing machine (model 5565, manufactured by Instron Japan) was used as the measuring device. The evaluation criteria are as follows. ○: Within a range of 0.01 to 0.6 N / 25 mm, ×: less than 0.01 N / 25 mm, or more than 0.6 N / 25 mm.

In Examples 1 to 9, no coating unevenness of the back layer forming coating solution was observed, and no release agent residue was generated. Moreover, in Examples 1-9, the unwinding strength at the time of tape use was controlled to the desired value as a dicing tape.
In contrast, Comparative Examples 1 and 2 in which the film thickness of the back layer is thin, Comparative Example 5 in which the solid content concentration of the release agent in the back layer forming coating liquid is low, and peeling in the back layer forming coating liquid In Comparative Example 4 in which the solid content concentration of the agent was low and the film thickness of the back layer was thin, coating unevenness occurred, and the remaining release agent was confirmed. Further, in Comparative Example 3 in which a powdered long-chain alkyl pendant polymer was used as a release agent, not only coating unevenness but also release agent precipitation occurred, and the remaining release agent was also confirmed.

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive layer 3 Back layer 10 Separator-less type dicing tape 20 Separator-less type dicing tape original fabric

Claims (5)

A base material, a pressure-sensitive adhesive layer formed on one surface of the base material and comprising a pressure-sensitive adhesive, an ionizing radiation curable compound and a crosslinking agent-containing material, and the other surface of the base material A back layer formed and containing a long chain alkyl polymer release agent,
The back layer is formed by applying a coating solution for forming a back layer containing the liquid long-chain alkyl polymer-based release agent in a solid content concentration of 4 to 10% by mass to the other surface of the substrate and drying it. And
A separatorless dicing tape, wherein the thickness of the back layer after drying is in the range of arithmetic average roughness Ra + (0.2 to 1.8) μm of the base material.   The separator-less dicing tape according to claim 1, wherein the substrate is made of unstretched polyethylene.   The separatorless dicing tape according to claim 1, wherein the ionizing radiation curable compound is an ultraviolet curable resin.   A separatorless dicing tape raw material obtained by winding the separatorless dicing tape according to any one of claims 1 to 3 in a roll shape with an adhesive layer as an inner side.   The separator-less dicing tape original fabric according to claim 4, wherein the unwinding strength is in a range of 0.01 to 0.6 N / 25 mm.

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