JP2012015340A - Separator-less dicing tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator-less dicing tape in which environmental impact and cost can be reduced and in which unwinding strength from an original fabric is controlled properly.SOLUTION: The separator-less dicing tape comprises: a substrate; an adhesive layer which is formed on one surface of the substrate and is made of an adhesive layer forming material including an adhesive, an ionizing radiation curable compound, and a cross-linking agent; and a back layer which is formed on the other surface of the substrate and includes at least a release agent.

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 during use is increased, and the workability is poor.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to reduce the environmental load and the cost, and to appropriately control the unwinding strength from the original fabric. And providing a separatorless dicing tape.

  The present inventor conducted extensive research to solve the above-mentioned problems, and formed a back layer containing a release agent on the surface opposite to the side where the adhesive layer of the substrate is formed. Thus, the inventors have found that the above problems can be solved, and have completed the present invention.

  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 And a back layer containing at least a release agent. A separatorless dicing tape, comprising:

  (2) The separator is a separatorless dicing tape according to (1), which is made of a polyolefin-based resin.

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

  (4) The pressure-sensitive adhesive layer is made of a material for forming a pressure-sensitive adhesive layer containing at least an isocyanate-based crosslinking agent as a crosslinking agent, and the content of the isocyanate-based crosslinking agent is 0.000 relative to 100 parts by mass of the pressure-sensitive adhesive. The separatorless dicing tape according to any one of (1) to (3), which is in the range of 2 to 10 parts by mass.

  (5) The separator-less dicing tape according to any one of (1) to (4), wherein the release agent is a long-chain alkyl release agent.

  (6) 180 ° peeling adhesive strength (conforming to JIS Z0237) of the pressure-sensitive adhesive layer to the silicon wafer is within a range of 0.5 to 15 N / 25 mm before curing, and 0.4 N / 25 mm after curing. The separator-less dicing tape according to any one of (1) to (5) below.

  (7) A separatorless dicing tape raw material obtained by winding the separatorless dicing tape according to any one of (1) to (6) in a roll shape with an adhesive layer as an inner side.

  (8) The separatorless dicing tape original fabric according to (7), 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.

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. It has an adhesive layer 2 made of an agent layer forming material and a back layer 3 formed on the other surface of the substrate 1 and containing at least a release agent, and does not have a 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. From the viewpoint of mechanical strength, a uniaxially stretched or biaxially stretched film is preferable. In the present invention, among the synthetic resins, polyolefin resins such as polypropylene and polyethylene are preferable. This is because the polyolefin resin is excellent in expandability and transparency to ultraviolet rays. In addition, according to the polyolefin-based resin, no harmful gas is generated at the time of incineration, so there is no concern about environmental pollution, and the tape can be reduced in weight.

  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.

[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. Further, 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 is within the range of 100,000 to 1,500,000. Is preferable, and it is more preferable to be in the range of 200,000 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 too small, the crosslink density after irradiation with ionizing radiation is not sufficient, and proper peelability may not be realized. Also, if the amount of ionizing radiation curable compound is too large, tack before ionizing radiation irradiation will increase significantly or cohesive force will decrease, so that the adhesive will protrude and contaminate the guide roll during production. Or an adhesive residue may occur 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, 0.05 to 10 mass with respect to 100 parts by mass of the pressure-sensitive adhesive. Part is preferable, 0.2 to 10 parts by mass is more preferable, and 2 to 10 parts by mass is particularly 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 too small, the adhesiveness between the pressure-sensitive adhesive layer and the base material becomes insufficient, or it becomes difficult for the pressure-sensitive adhesive layer to have sufficient strength, and an adherend such as a wafer. When peeling from the adhesive layer, the pressure-sensitive adhesive layer may cause cohesive failure and adhesive residue may occur. If the amount of the isocyanate-based crosslinking agent is too large, it remains as an unreacted monomer in the pressure-sensitive adhesive layer, and thus the cohesive force may be reduced.

  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. If the amount of the epoxy-based crosslinking agent is too small, 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, resulting in adhesive residue. Sometimes. If the amount of the epoxy-based cross-linking agent is too large, the adhesive strength 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 0.05-10 mass parts with respect to 100 mass parts of adhesives, and is 0.1-10 mass parts. It is more preferable. If the amount of the photopolymerization initiator is too small, the polymerization initiation reaction is not sufficient, the adhesive strength after irradiation with ionizing radiation becomes excessively high, and proper peelability may not be realized. If the amount of the photopolymerization initiator is too large, 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 adhesive strength of the pressure-sensitive adhesive layer of the separatorless dicing tape of the present invention is peeled off from the silicon wafer by 180 ° (according to JIS Z0237) within the range of 0.5 to 15 N / 25 mm before curing by irradiation with ionizing radiation. In addition, it is preferably 0.4 N / 25 mm or less after curing, and is within a range of 0.5 to 10 N / 25 mm before curing by irradiation with ionizing radiation, and 0.3 N / 25 mm after curing. The following is more preferable. If the adhesive force before curing by irradiation with ionizing radiation is within the above range, a silicon wafer or the like can be appropriately protected or fixed. Moreover, if the adhesive force after hardening by irradiation of ionizing radiation is the said range, generation | occurrence | production of adhesive residue and cohesive failure can be suppressed. The adhesive strength was determined by pasting a separatorless dicing tape specimen cut to a width of 25 mm and a length of 150 mm on a mirror surface of a silicon wafer and leaving it to stand at room temperature and humidity for 20 minutes. It can measure by peeling off from the mirror surface in the length direction of a test piece (peeling speed: 300 mm / min, peeling distance: 50 mm, peeling angle: 180 °). A universal material testing machine (model 5565, manufactured by Instron Japan) can be used as the measuring apparatus.

[Back layer]
In the separatorless dicing tape of the present invention, the back layer is formed on the surface of the substrate opposite to the surface on which the pressure-sensitive adhesive layer is formed, and contains at least a release agent.

(paint remover)
The release agent is not particularly limited as long as a predetermined unwinding strength can be obtained, and examples thereof include a long-chain alkyl release agent, a fluorine release agent, and a silicone release agent. Considering the generation of harmful gas at the time of disposal and the contamination to electric / electronic parts, it is preferable to use a long-chain alkyl release agent. Here, the long-chain alkyl refers to those having 12 to 40 carbon atoms, preferably those having 12 to 30 carbon atoms. The release agent may be in the form of powder or liquid as long as it does not interfere with the formation of the back layer.

  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.

(Substrate formation method)
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 an olefin resin, 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.

(Method for forming pressure-sensitive adhesive layer)
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, although the application quantity of the coating liquid for adhesive layer formation changes with kinds of ionizing radiation hardening type compound, it is preferable to adjust so that the film thickness of the adhesive layer after drying may be 2-100 micrometers.

(Formation method of back layer)
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. And a method of forming the substrate by applying it to the substrate by coating or the like. 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 melt | dissolved or disperse | distributed, 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 not particularly limited, but is preferably adjusted so that the solid content concentration of the release agent is 3 to 20%. Moreover, the coating amount of the coating liquid for forming the back layer is not particularly limited as long as sufficient peeling performance is exhibited, but the thickness of the back layer after drying is 0.2-2. It is preferable to adjust so that it may become 0.0 micrometer.

  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>
100 parts by weight of a release agent (long-chain alkyl pendant polymer, trade name: Pyroyl 1050, mass average molecular weight: 100,000, liquid release agent, manufactured by Yushi Kogyo Co., Ltd.) is diluted with 100 parts by weight of toluene and sufficiently dispersed. Thus, a back layer forming coating solution was prepared. This back layer forming coating solution was applied to the entire surface of the substrate (polyethylene film, thickness: 100 μm) by a gravure coating method so that the film thickness after drying was 0.5 μm, A back layer was formed by drying with hot air.
Next, the entire surface of the base material is coated with a coating solution for forming an adhesive layer having the composition shown in Table 1 so as to have a film thickness after drying of 10 μm by a die coating method, and then dried with hot air. Thus, a pressure-sensitive adhesive layer was formed to obtain a separatorless dicing tape (back layer / base material / pressure-sensitive adhesive layer). 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>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 1 except that the coating liquid for forming the pressure-sensitive adhesive layer having the composition shown in Table 2 was used.

<Example 3>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 1 except that a substrate having a thickness of 150 μm was used.

<Example 4>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 2 except that a substrate having a thickness of 150 μm was used.

<Example 5>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 1 except that the coating solution for forming an adhesive layer having the composition shown in Table 3 was used.

<Example 6>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 1 except that the coating liquid for forming the pressure-sensitive adhesive layer having the composition shown in Table 4 was used.

<Example 7>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 1 except that a base material (polypropylene film, trade name: Dynasoft, thickness: 100 μm, manufactured by JSR Trading) was used.

<Example 8>
A separatorless dicing tape and its original fabric were obtained in the same manner as in Example 2 except that a base material (polypropylene film, trade name: Dynasoft, thickness: 100 μm, manufactured by JSR Trading) was used.

<Comparative Example 1>
On one surface of a base material (polyethylene film, thickness: 100 μm), a coating solution for forming an adhesive layer having the composition shown in Table 5 is applied over the entire surface by a die coating method so that the film thickness after drying is 10 μm. And dried with hot air to form an adhesive layer.
Next, a separator (single-sided silicone-treated PET film, trade name: SP-PET-01, thickness: 38 μm, manufactured by Tosero Co., Ltd.) is pasted on the surface of the pressure-sensitive adhesive layer opposite to the base material, and a dicing tape ( Substrate / adhesive layer / separator) was obtained. After slitting this dicing tape into a width of 300 mm, the dicing tape was wound up to 100 m and aged at 40 ° C. for 72 hours to prepare a dicing tape original. In addition, the said dicing tape original fabric was produced in one process in-line, using one coating apparatus.

<Comparative example 2>
A dicing tape and its original fabric were obtained in the same manner as in Comparative Example 1 except that the adhesive layer-forming coating solution having the formulation shown in Table 2 was used.

<Comparative Example 3>
On one surface of a base material (polyethylene film, thickness: 100 μm), a coating solution for forming an adhesive layer having the composition shown in Table 2 is applied over the entire surface by a die coating method so that the film thickness after drying is 10 μm. And dried with hot air to form a pressure-sensitive adhesive layer to obtain a dicing tape (base material / pressure-sensitive adhesive layer). Next, after slitting this dicing tape to a width of 300 mm, the dicing tape was wound up to 100 m and aged at 40 ° C. for 72 hours to prepare a dicing tape original. In addition, the said dicing tape original fabric was produced in one process in-line, using one coating apparatus.

  About the dicing tape obtained in the said Examples 1-8 and Comparative Examples 1-3 or its original fabric, adhesive force evaluation, unwinding strength evaluation, and the weight measurement of the original fabric were performed. The results are shown in Table 6.

[Adhesive strength evaluation]
The dicing tapes obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were cut into a width of 25 mm and a length of 150 mm to prepare test pieces. This test piece was affixed to the mirror surface of a silicon wafer and left at room temperature and humidity for 20 minutes. Thereafter, using a universal material testing machine (model 5565, manufactured by Instron Japan), the adhesive strength was measured (according to JIS Z0237, peeling speed: 300 mm / min, peeling distance: 50 mm, peeling angle: 180 °, temperature condition) : 24 ° C., humidity condition: 50% RH).
Moreover, the said test piece was laminated on the mirror surface of the silicon wafer, and it was left to stand under normal temperature normal humidity for 20 minutes. Then, after irradiating ultraviolet light (integrated light amount: 200 mj / cm ² ) using a fusion H / bulb lamp as a light source from the base material side, a universal material testing machine (model 5565, manufactured by Instron Japan) was used. Then, the adhesive strength was measured (according to JIS Z0237, peeling speed: 300 mm / min, peeling distance: 50 mm, peeling angle: 180 °).
The evaluation criteria are as follows. ○: Adhesive strength before crosslinking and curing by ultraviolet irradiation is in the range of 0.5 to 15 N / 25 mm, and adhesive strength after crosslinking and curing is 0.4 N / 25 mm or less, ×: Before crosslinking and curing by ultraviolet irradiation Adhesive strength is less than 0.5 N / 25 mm or more than 15 N / 25 mm, or the adhesive strength after cross-linking curing is more than 0.4 N / 25 mm.

[Evaluation of unwinding strength]
From the dicing tape original fabrics obtained in Examples 1 to 8 and Comparative Examples 1 to 3, the dicing tape in a state where two layers of 25 mm width × 150 mm length overlap each other (Examples 1 to 8: back layer / Base material / pressure-sensitive adhesive layer / back layer / base material / pressure-sensitive adhesive layer, comparative examples 1 and 2: base material / pressure-sensitive adhesive layer / separator / base material / pressure-sensitive adhesive layer / separator, comparative example 3: base material / pressure-sensitive adhesive 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.

[Material weight measurement]
The dicing tape original fabric obtained in Examples 1 to 8 and Comparative Examples 1 to 3 was weighed.

As shown in Table 6, in Examples 1 to 8, it was possible to confirm that a separatorless dicing tape in which the adhesive strength before and after UV irradiation and the unwinding strength during use were well controlled and the original fabric were obtained. It was.
Since the dicing tape original fabric having the separator (Comparative Examples 1 and 2) is heavier than the separatorless dicing tape original fabric having no separator (Examples 1 to 8), the work during transportation and disposal The load is thought to increase.
In Comparative Example 3 having neither a separator nor a back layer containing a release agent, the adhesive force between the substrate and the pressure-sensitive adhesive layer was strong, and smooth peeling could not be performed.

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 (8)

  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 separatorless dicing tape, comprising a back layer formed and containing at least a release agent.   The separator-less dicing tape according to claim 1, wherein the base material is made of a polyolefin-based resin.   The separatorless dicing tape according to claim 1, wherein the ionizing radiation curable compound is an ultraviolet curable resin.   The pressure-sensitive adhesive layer is made of a material for forming a pressure-sensitive adhesive layer containing at least an isocyanate-based crosslinking agent as a crosslinking agent, and the content of the isocyanate-based crosslinking agent is 0.2 to 10 parts by mass with respect to 100 parts by mass of the pressure-sensitive adhesive. The separator-less dicing tape according to any one of claims 1 to 3, which is in a range of mass parts.   The separator-less dicing tape according to claim 1, wherein the release agent is a long-chain alkyl release agent.   180 degree peeling adhesion (based on JIS Z0237) of the pressure-sensitive adhesive layer to the silicon wafer is within a range of 0.5 to 15 N / 25 mm before curing, and is 0.4 N / 25 mm or less after curing. The separator-less type dicing tape according to claim 1.   A separatorless dicing tape raw material obtained by winding the separatorless dicing tape according to any one of claims 1 to 6 in a roll shape with an adhesive layer as an inner side.   The separator-less dicing tape original fabric according to claim 7, wherein the unwinding strength is in a range of 0.01 to 0.6 N / 25 mm.

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