JP7260017B1 - Adhesive tape for semiconductor processing - Google Patents

Abstract

A low-contamination adhesive tape for semiconductor processing is provided. Kind Code: A1 A semiconductor processing adhesive tape 10 having a substrate 1 and an energy ray-curable adhesive layer 2 disposed on one surface of the substrate, wherein L*a* is determined by the following test. The color difference ΔE*ab in the b* color system is 2.0 or less. Test: (1) The surface of the adhesive layer of the adhesive tape for semiconductor processing is laminated to a copper foil to prepare a laminate. (2) The laminate is stored for 6 days in an environment where the temperature is 25° C.±5° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked. (3) The adhesive tape for semiconductor processing of the laminate is irradiated with energy rays to cure the adhesive layer. (4) Peel off the adhesive tape for semiconductor processing from the laminate. (5) Color difference in the L*a*b* color system between the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adherend surface of the copper foil after peeling of the adhesive tape for semiconductor processing Determine ΔE*ab. [Selection drawing] Fig. 1

Description

The present disclosure relates to an adhesive tape for semiconductor processing.

In semiconductor manufacturing processes, adhesive tapes for semiconductor processing, such as dicing tapes and backgrind tapes, are used to fix and protect parts.

Adhesive tapes for semiconductor processing are required to be able to fix components with sufficient adhesive strength during the processing process and to be easily peelable after the processing process without damaging the components.

As such adhesive tapes for semiconductor processing, for example, energy ray-curable adhesive tapes have been actively developed (for example, Patent Documents 1 to 3). Energy ray-curable adhesive tapes can be reduced in adhesive force by curing the adhesive layer with energy ray irradiation. It is possible to achieve both

WO2015/133420 Japanese Unexamined Patent Application Publication No. 2005-23188 JP 2014-154796 A

Since the semiconductor processing pressure-sensitive adhesive tape is attached to the adherend during the processing step, the semiconductor processing pressure-sensitive adhesive tape and the adherend are in contact with each other for a long period of time. Therefore, the components contained in the pressure-sensitive adhesive tape for semiconductor processing may migrate to the surface of the adherend, thereby contaminating the adherend. If the surface of the adherend is contaminated, it may cause poor adhesion or peeling in the subsequent steps of the semiconductor manufacturing process, such as the wiring process and the encapsulation process, resulting in a decrease in semiconductor performance and reliability. There's a problem.

The present disclosure has been made in view of the above circumstances, and a main object thereof is to provide a low-contamination adhesive tape for semiconductor processing.

The inventors of the present disclosure made intensive studies to solve the above problems, and as a result, obtained the following findings. Contamination of the adherend by the adhesive tape for semiconductor processing is a change in the surface state of the adherend. The inventors of the present disclosure have extensively studied methods for evaluating the surface state of an adherend, and focused on the color of the surface of the adherend. Furthermore, in semiconductors, as copper wiring is widely used with miniaturization and speeding up, attention was paid to copper foil as an adherend. Then, the change in the surface state of the copper foil, which is the adherend, can be evaluated by the color difference ΔE ^* _ab of the adherend surface of the copper foil before lamination and after peeling of the adhesive tape for semiconductor processing, and furthermore, the color difference ΔE ^* _ab was found to be suitable for evaluation of contamination of an adherend by an adhesive tape for semiconductor processing. The present disclosure is based on such findings.

One embodiment of the present disclosure is a semiconductor processing adhesive tape having a substrate and an energy ray-curable adhesive layer disposed on one surface of the substrate, wherein L Provided is an adhesive tape for semiconductor processing having a color difference ΔE ^* _ab of 2.0 or less in a ^* a ^* b ^* color system. Test: It has the following steps (1) to (5) in order. (1) The surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to a copper foil to prepare a laminate. (2) The laminate is stored for 6 days in an environment where the temperature is 25° C.±5° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked. (3) The adhesive tape for semiconductor processing of the laminate is irradiated with energy rays to cure the adhesive layer. (4) Peel off the adhesive tape for semiconductor processing from the laminate. (5) L ^* a ^* b ^* table of the adhesion surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adhesion surface of the copper foil after peeling of the adhesive tape for semiconductor processing. Obtain the color difference ΔE ^* _ab in the color system.

The adhesive tape for semiconductor processing according to the present disclosure has the effect of being able to suppress contamination of adherends.

1 is a schematic cross-sectional view showing an example of an adhesive tape for semiconductor processing in the present disclosure; FIG. It is process drawing which illustrates the manufacturing method of a semiconductor. It is process drawing which illustrates the manufacturing method of a semiconductor.

Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be embodied in many different modes and should not be construed as limited to the description of the embodiments exemplified below. In addition, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual form, but this is only an example and limits the interpretation of the present disclosure. not something to do. In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate.

In this specification, when expressing a mode in which another member is arranged on top of a certain member, the term “above” or “below” simply means that it is in contact with a certain member unless otherwise specified. , arranging another member directly above or below, and arranging another member above or below a certain member via another member. In addition, in this specification, when expressing a mode in which another member is arranged on the surface of a certain member, unless otherwise specified, when simply described as “on the surface”, it means directly above or in contact with a certain member, unless otherwise specified. It includes both the case of arranging another member directly below and the case of arranging another member above or below a certain member via another member.

The adhesive tape for semiconductor processing of the present disclosure will be described below.

The adhesive tape for semiconductor processing of the present disclosure has a substrate and an energy ray-curable adhesive layer disposed on one surface of the substrate, and has L ^* a ^* b ^* determined by the following test. The color difference ΔE ^* _ab in the color system is 2.0 or less. Test: It has the following steps (1) to (5) in order. (1) The surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to a copper foil to prepare a laminate. (2) The laminate is stored for 6 days in an environment where the temperature is 25° C.±5° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked. (3) The adhesive tape for semiconductor processing of the laminate is irradiated with energy rays to cure the adhesive layer. (4) Peel off the adhesive tape for semiconductor processing from the laminate. (5) L ^* a ^* b ^* table of the adhesion surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adhesion surface of the copper foil after peeling of the adhesive tape for semiconductor processing. Obtain the color difference ΔE ^* _ab in the color system.

FIG. 1 is a schematic cross-sectional view illustrating the adhesive tape for semiconductor processing of the present disclosure. A semiconductor processing adhesive tape 10 shown in FIG. In the pressure-sensitive adhesive tape for semiconductor processing 10, the color difference ΔE ^* _ab determined by the test is equal to or less than a predetermined value.

In the present disclosure, the color difference ΔE ^* _ab between the adhesion surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adhesion surface of the copper foil after peeling of the adhesive tape for semiconductor processing, which is obtained by the above test. is less than or equal to a predetermined value. This indicates that there is little change in the surface condition of the adherend surface of the copper foil between before lamination and after peeling of the pressure-sensitive adhesive tape for semiconductor processing.

Here, for example, the following three factors can be cited as factors that change the surface state of the copper foil. The first is that adhesive residue is left when the adhesive tape for semiconductor processing is peeled off. The second is that the components contained in the adhesive tape for semiconductor processing, especially the low-molecular-weight components migrate to the surface of the copper foil. The third is that the components contained in the adhesive tape for semiconductor processing react with copper. When the surface condition of the copper foil changes due to the above factors, it is considered to appear as a color difference.

Therefore, in the present disclosure, when the color difference ΔE ^* _ab is equal to or less than a predetermined value, it can be said that migration of components contained in the pressure-sensitive adhesive tape for semiconductor processing to the surface of the adherend can be suppressed. Moreover, it can be said that it can suppress that the component and copper which are contained in the adhesive tape for semiconductor processing react. Therefore, contamination of the adherend can be suppressed. Furthermore, it can be said that the adhesive residue on the adherend can be suppressed when the adhesive tape for semiconductor processing is peeled off. Therefore, it is possible to improve the performance and reliability of semiconductors.

For example, Patent Document 1 discloses evaluating contamination of adherends by organic substances contained in the adhesive tape for semiconductor processing based on the water contact angle on the surface of the silicon wafer after the adhesive tape for semiconductor processing has been peeled off. ing. However, as described above, the factors that change the surface condition of the adherend are not limited to the migration of the organic substances contained in the pressure-sensitive adhesive tape for semiconductor processing to the surface of the adherend.

On the other hand, as described above, even if the surface condition of the copper foil changes due to any of the above factors, it is considered to appear as a color difference. Therefore, in the present disclosure, by adopting the color difference ΔE ^* _ab , the surface state of the adherend can be accurately evaluated, and further, the contamination of the adherend by the adhesive tape for semiconductor processing can be suitably evaluated. It is possible.

Hereinafter, each configuration of the adhesive tape for semiconductor processing of the present disclosure will be described.

1. Characteristics of the adhesive tape for semiconductor processing In the adhesive tape for semiconductor processing of the present disclosure, the color difference ΔE ^* _ab in the L ^* a ^* b ^* color system obtained by the following test is 2.0 or less, preferably 1. 0.8 or less, more preferably 1.5 or less. The color difference ΔE ^* _ab is preferably small, and the lower limit is not particularly limited.

Test: It has the following steps (1) to (5) in order.
(1) The surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to a copper foil to prepare a laminate.
(2) The laminate is stored for 6 days in an environment where the temperature is 25° C.±5° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked.
(3) The adhesive tape for semiconductor processing of the laminate is irradiated with energy rays to cure the adhesive layer.
(4) Peel off the adhesive tape for semiconductor processing from the laminate.
(5) L ^* a ^* b ^* table of the adhesion surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adhesion surface of the copper foil after peeling of the adhesive tape for semiconductor processing. Obtain the color difference ΔE ^* _ab in the color system.

In the above step (1), first, the adhesive tape for semiconductor processing is cut into a size of 40 mm or more in width and 100 mm or more in length. As the copper foil, a 35 μm-thick rolled copper foil “RCF-T5B” manufactured by Fukuda Metal Foil & Powder Co., Ltd. is used. Then, the shiny surface of the rolled copper foil is wiped with isopropyl alcohol (IPA) and dried thoroughly. After that, the surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to the glossy surface of the rolled copper foil. At this time, in an environment where the temperature is 25 ° C. ± 5 ° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked, the surface of the adhesive layer of the adhesive tape for semiconductor processing is placed on the glossy surface of the rolled copper foil, 2 kg Lamination is performed by reciprocating the roller twice. Moreover, at this time, if the adhesive tape for semiconductor processing has a separator, the separator may be peeled off to expose the adhesive layer.

As described above, in the semiconductor manufacturing process, the adhesive tape for semiconductor processing and the adherend are in contact for a long time. Therefore, in the above step (1), the storage conditions are set to standard temperature and humidity, and the storage period is set to be slightly longer.

In the above step (2), the energy ray to be blocked is an energy ray capable of curing the energy ray-curable adhesive layer, and is appropriately selected according to the type of the adhesive layer. Energy rays will be described later.

In the step (3), the energy ray to be irradiated is an energy ray capable of curing the energy ray-curable adhesive layer, and is appropriately selected according to the type of the adhesive layer. In addition, the energy ray irradiation conditions (e.g., wavelength, integrated light intensity, etc.) may be conditions that allow the energy ray-curable adhesive layer to be cured, and may be appropriately determined according to the composition, thickness, etc. of the adhesive layer. selected. Specific energy ray irradiation conditions include conditions under which ultraviolet rays with a wavelength of 400 nm or less, particularly ultraviolet rays with a wavelength of 365 nm are irradiated with an accumulated light amount of 200 mJ/cm ^{2 or} more.

In the above step (4), when peeling the adhesive tape for semiconductor processing from the laminate, it is preferable to set the peeling speed to approximately 100 mm/min or more and 1000 mm/min or less, for example.

In the above step (5), the L ^* a ^* b ^* color system is a color system defined by the International Commission on Illumination (CIE) in 1976 and also defined in JIS Z8781-4. The color difference ΔE ^* _ab is calculated by the following formula.
ΔE ^* _ab = {(ΔL ^* ) ² +(Δa ^* ) ² +(Δb ^* ) ² } ^1/2
(In the above formula, ΔL ^* is the lightness L * of the surface to be adhered of the copper foil before lamination of the adhesive tape for semiconductor processing ^, and the lightness L ^* of the surface to be adhered of the copper foil after peeling the adhesive tape for semiconductor processing. In addition, Δa ^* is the chromaticity a ^* of the copper foil adherend surface before lamination of the semiconductor processing adhesive tape, and the copper foil adherend surface after peeling of the semiconductor processing adhesive tape. In addition, Δb ^* is the difference between the chromaticity b ^* of the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the chromaticity b ^* of the copper foil after peeling the adhesive tape for semiconductor processing. It is the difference from the chromaticity b ^* of the adherend surface of the foil.)

The lightness L ^* , chromaticity a ^* , and b ^* of the surface to be adhered of the copper foil before lamination of the adhesive tape for semiconductor processing and the surface to be adhered of the copper foil after peeling of the adhesive tape for semiconductor processing are in accordance with JIS Z8722. and can be measured using a spectrophotometer. The measurement conditions are D65 light source, 10° field of view, and reflection measurement. As the spectrophotometer, for example, a device capable of reflection measurement such as "Spectrophotometer SE6000" manufactured by Nippon Denshoku Industries Co., Ltd. can be used.

In the above step (5), when measuring the lightness L ^* , chromaticity a ^* , and b ^* of the adherend surface of the copper foil after bonding the adhesive tape for semiconductor processing, the adhesive tape for semiconductor processing was measured from the laminate. After peeling off the tape, the measurement is performed as it is. On the other hand, when measuring the lightness L ^* , chromaticity a ^* , and b ^* of the surface to be adhered of the copper foil before lamination of the adhesive tape for semiconductor processing, the surface to be adhered of the copper foil was wiped with isopropyl alcohol and thoroughly Measurements are taken after drying.

In addition, the adhesive force of the energy ray-curable adhesive layer is reduced by being cured by the irradiation of the energy ray. In the above step (1), the surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to the glossy surface of the rolled copper foil, not to the rough surface of the rolled copper foil. Therefore, the adhesive tape for semiconductor processing can be easily peeled off from the laminate. Therefore, it is considered that the peeling of the adhesive tape for semiconductor processing hardly deforms the copper foil. Therefore, the above-mentioned color difference ΔE ^* _ab captures changes in the surface state of the copper foil due to the adhesive tape for semiconductor processing, and is not due to deformation of the copper foil.

In addition, if there is concern about deformation of the copper foil due to peeling of the adhesive tape for semiconductor processing, the copper foil may be fixed in advance to a rigid substrate such as a SUS plate or a glass plate with double-sided tape or the like before use.

Means for controlling the color difference ΔE ^* _ab include, for example, a method of adjusting the composition of the substrate, a method of adjusting the method of forming the substrate, a method of adjusting the composition of the adhesive layer, and adjusting the degree of cross-linking of the adhesive. method, a method of arranging a primer layer between the substrate and the adhesive layer, and the like.

Methods for adjusting the composition of the substrate include, for example, methods for adjusting the content and molecular weight of additives. For example, by reducing the content of the additive, it is possible to suppress migration of components contained in the base material to the surface of the adherend via the adhesive layer, and as a result, the color difference ΔE ^* _ab can be reduced. can be made smaller. Further, for example, by increasing the molecular weight of the additive, it is possible to suppress migration of components contained in the base material to the surface of the adherend via the adhesive layer, and as a result, the color difference ΔE ^* _ab can be made smaller. Specifically, by using a polymer-type additive, it is possible to suppress migration of components contained in the base material to the surface of the adherend via the adhesive layer.

As a method of adjusting the method of forming the base material, for example, there is a method of sufficiently melting the resin composition when the resin composition is melted and molded. By sufficiently melting the resin composition, the dispersibility of the additive contained in the resin composition is improved, so that the additive is stably present in the base material. This makes it possible to suppress migration of components contained in the base material to the surface of the adherend via the adhesive layer, and as a result, it is possible to reduce the color difference ΔE ^* _ab .

Methods for adjusting the composition of the adhesive layer include, for example, a method of adjusting the molecular weight of the adhesive main agent and additives, a method of adjusting the glass transition temperature of the adhesive main agent and additives, and a method of adjusting the compatibility of the adhesive main agent and additives. method, a method of adding a cross-linking agent, and a method of adjusting the type and number of functional groups of the adhesive main agent and the energy ray-curable compound.

For example, in the method of adjusting the molecular weight of the adhesive main agent, by increasing the molecular weight of the adhesive main agent, it is possible to suppress the migration of the components contained in the adhesive layer to the surface of the adherend. The color difference ΔE ^* _ab can be reduced. Further, for example, in the method of adjusting the molecular weight of the additive, by increasing the molecular weight of the additive, it is possible to suppress the migration of the components contained in the adhesive layer to the surface of the adherend, resulting in , the color difference ΔE ^* _ab can be reduced. Specifically, by using a polymer type additive or by using an additive that can be crosslinked, it is possible to suppress the migration of the components contained in the adhesive layer to the surface of the adherend. can.

Further, for example, in the method of adjusting the glass transition temperature of the adhesive main agent, by increasing the glass transition temperature of the adhesive main agent, it is possible to suppress the migration of the components contained in the adhesive layer to the surface of the adherend. As a result, the color difference ΔE ^* _ab can be reduced. Further, for example, in the method of adjusting the glass transition temperature of the additive, by increasing the glass transition temperature of the additive, it is possible to suppress the migration of the components contained in the adhesive layer to the surface of the adherend. As a result, the color difference ΔE ^* _ab can be reduced.

Further, for example, in the method of adjusting the compatibility of the main adhesive agent and additives, by increasing the compatibility of the main adhesive agent and additives, the components contained in the adhesive layer are suppressed from migrating to the surface of the adherend. As a result, the color difference ΔE ^* _ab can be reduced. Specifically, the compatibility of the main adhesive and additives can be adjusted by adjusting the polarity, molecular weight, composition ratio, mixing method, and the like of the main adhesive and additives.

For example, in the method of adding a cross-linking agent, the reaction between the functional group of the main adhesive agent and the cross-linking agent can reduce the unreacted functional groups that have not reacted with the cross-linking agent. Reaction with groups can be suppressed. As a result, the color difference ΔE ^* _ab can be reduced. In addition, by cross-linking the adhesive main agent with a cross-linking agent, the cohesive force is increased, so that the components contained in the adhesive layer can be suppressed from migrating to the surface of the adherend, and as a result, the color difference ΔE ^* _ab can be made smaller.

Further, for example, in the method of adjusting the type of the functional group of the adhesive main agent, the functional group that can react with the cross-linking agent is a functional group that is difficult to react with copper, so that the unreacted non-reacted with the cross-linking agent Even if the functional group remains, the reaction between copper and the functional group can be suppressed, and as a result, the color difference ΔE ^* _ab can be reduced.

Further, for example, in the method of adjusting the type of the functional group of the energy ray-curable compound, the energy ray-curable functional group or the functional group that can react with the cross-linking agent is a functional group that does not readily react with copper. Reaction between copper and functional groups can be suppressed, and as a result, the color difference ΔE ^* _ab can be reduced. Further, for example, in the method of adjusting the number of functional groups in the energy ray-curable compound, the energy ray-curable functional group and the functional group capable of reacting with the cross-linking agent are reduced in the number of functional groups, so that copper and the functional group can suppress the reaction with As a result, the color difference ΔE ^* _ab can be reduced.

In the method of adjusting the degree of cross-linking of the pressure-sensitive adhesive, increasing the degree of cross-linking of the pressure-sensitive adhesive increases the cohesive force, thereby suppressing migration of components contained in the pressure-sensitive adhesive layer to the surface of the adherend. , and as a result, the color difference ΔE ^* _ab can be reduced.

In the method of arranging the primer layer between the substrate and the adhesive layer, the primer layer can suppress the migration of components contained in the substrate to the surface of the adherend via the adhesive layer, As a result, the color difference ΔE ^* _ab can be reduced.

In addition, in the adhesive tape for semiconductor processing of the present disclosure, the adhesive strength to the SUS plate before energy beam irradiation is, for example, preferably 1 N/25 mm or more, more preferably 3 N/25 mm or more, and 5 N/ More preferably, it is 25 mm or more. When the adhesive strength to the SUS plate is within the above range, the adherend can be sufficiently fixed to the adhesive tape for semiconductor processing until the energy beam is irradiated. On the other hand, the upper limit of the adhesive strength to the SUS plate is not particularly limited.

Here, the adhesive strength to the SUS plate is measured by JIS Z0237: 2009 (adhesive tape/adhesive sheet test method) test method method 1 (temperature 23 ° C humidity 50% RH, tape and sheet at 180 ° to the stainless steel test plate. peeling off test method), and peeled off in the longitudinal direction of the test piece under conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm/min. As the SUS plate, a SUS304, BA surface finish, 1.5 mm thick, 100 mm wide, and 150 mm long SUS plate can be used.

In addition, in the adhesive tape for semiconductor processing of the present disclosure, the adhesive strength to the SUS plate after irradiation with the energy beam is, for example, preferably 2 N/25 mm or less, more preferably 1 N/25 mm or less. When the adhesive strength to the SUS plate after irradiation with energy rays is within the above range, the adherend can be easily peeled off from the adhesive tape for semiconductor processing after irradiation with energy rays. On the other hand, the lower limit of the adhesive strength to the SUS plate after the energy beam irradiation is not particularly limited, but can be, for example, 0.01 N/25 mm or more.

Here, the adhesive strength to the SUS plate after energy beam irradiation can be measured by the following method. First, the adhesive layer of the adhesive tape for semiconductor processing is irradiated with energy rays to be cured. At this time, for example, the energy beam can be irradiated from the substrate side surface of the pressure-sensitive adhesive tape for semiconductor processing. Next, according to JIS Z0237: 2009 (adhesive tape/adhesive sheet test method) test method method 1 (temperature 23 ° C humidity 50% RH, tape and sheet are peeled off at 180 ° against a stainless steel test plate). By peeling the test piece in the longitudinal direction under conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm/min, the adhesive force to the SUS plate after energy beam irradiation can be measured. As the SUS plate, a SUS304, BA surface finish, 1.5 mm thick, 100 mm wide, and 150 mm long SUS plate can be used.

2. Adhesive Layer The adhesive layer in the present disclosure is a member that is arranged on one surface of the substrate and has energy ray curability. The energy ray-curable adhesive layer is cured by irradiation with an energy ray, thereby reducing its adhesive force. The energy ray-curable adhesive layer can fix the adherend by its initial adhesive strength. In addition, in the energy ray-curable adhesive layer, when cured by irradiation with an energy ray, the adhesive strength is reduced and the releasability is improved, so that the adherend can be detached or transferred.

Examples of energy rays include light 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 beams and neutron beams. Among them, from the viewpoint of versatility, ultraviolet rays and electron beams are preferred, and ultraviolet rays are more preferred.

The adhesive layer is not particularly limited as long as it satisfies the above adhesive strength, and for example, it can contain at least a resin (adhesive main agent) and an energy ray-curable compound. When the adhesive layer contains an energy ray-curable compound, the energy ray-curable compound can be cured by irradiation with energy rays, thereby reducing the adhesive force, and at this time, the cohesive force increases, so the peeling becomes easier.

(1) Resin (base adhesive)
Examples of the resin (adhesive main agent) include resins generally used as main agents for adhesives, such as acrylic resins, polyester resins, polyimide resins, and silicone resins. Among them, acrylic resins are preferable. By using an acrylic resin, adhesive residue on the adherend can be reduced.

Therefore, the adhesive layer preferably contains at least an acrylic resin, an energy ray-curable compound, and a cross-linking agent. In the adhesive layer, the acrylic resin usually exists as a crosslinked product obtained by cross-linking the acrylic resins with a crosslinking agent, but the acrylic resin alone may be contained together with the crosslinked product.

(acrylic resin)
The acrylic resin is not particularly limited, and for example, a (meth)acrylic acid ester polymer obtained by homopolymerizing a (meth)acrylic acid ester, a (meth)acrylic acid ester as a main component, and a (meth)acrylic acid ester (Meth)acrylic acid ester copolymers obtained by copolymerizing with other monomers can be mentioned. Among them, (meth)acrylic acid ester copolymers are preferred. Specific examples of (meth)acrylic acid esters and other monomers include those disclosed in JP-A-2012-31316. Other monomers can be used alone or in combination of two or more.

Among them, the acrylic resin is a (meth)acrylic acid ester copolymer obtained by copolymerizing a (meth)acrylic acid ester as a main component and a copolymerizable hydroxyl group-containing monomer with the above (meth)acrylic acid ester. , or (meth) acrylic acid ester as a main component, the (meth) acrylic acid ester copolymer obtained by copolymerization with the hydroxyl group-containing monomer and carboxyl group-containing monomer copolymerizable with the (meth) acrylic acid ester It can be used preferably.

In this specification, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

The copolymerizable hydroxyl group-containing monomer and carboxyl group-containing monomer are not particularly limited, and for example, hydroxyl group-containing monomers and carboxyl group-containing monomers disclosed in JP-A-2012-31316 are used.

The ΔE ^* _ab can be controlled by adjusting the molecular weight of the acrylic resin. Specifically, as described above, ΔE ^* _ab can be reduced by increasing the molecular weight of the acrylic resin. The weight average molecular weight of the acrylic resin is, for example, preferably 100,000 or more and 2,000,000 or less, more preferably 200,000 or more and 1,000,000 or less. By setting the weight-average molecular weight of the acrylic resin within the above range, it is possible to reduce adhesive residue and contamination on the adherend.

Here, in this specification, the weight average molecular weight is a polystyrene conversion value when measured by gel permeation chromatography (GPC). The weight average molecular weight is, for example, HLC-8220GPC manufactured by Tosoh Corporation as a measuring device, TSKGEL-SUPERMULTIPORE-HZ-M manufactured by Tosoh Corporation as a column, THF as a solvent, and molecular weights of 1050 and 5970 as standards. It can be measured by using standard polystyrene of 18100, 37900, 96400, 706000.

In addition, ΔE ^* _ab can be controlled by adjusting the glass transition temperature of the acrylic resin. Specifically, as described above, ΔE ^* _ab can be reduced by increasing the glass transition temperature of the acrylic resin. The glass transition temperature of the acrylic resin is appropriately adjusted.

Moreover, the acrylic resin may have energy ray-curable properties, and may have, for example, an energy ray-curable functional group in its side chain. The energy ray-curable functional group preferably has, for example, an ethylenically unsaturated bond, and specific examples thereof include (meth)acryloyl groups, vinyl groups, and allyl groups.

(2) Energy ray-curable compound The energy ray-curable compound is not particularly limited as long as it polymerizes upon exposure to energy rays, and examples thereof include compounds having an energy ray-curable functional group.

Energy ray-curable compounds include, for example, energy ray-curable monomers, energy ray-curable oligomers, and energy ray-curable polymers. Note that the energy ray-curable polymer is a polymer different from the resin (main adhesive agent) described above. Among them, energy ray-curable oligomers are preferable from the viewpoint of the balance of adhesive strength before and after energy ray irradiation. Also, an energy ray-curable monomer, an energy ray-curable oligomer, and an energy ray-curable polymer may be used in combination. For example, when an energy ray-curable monomer is used in addition to an energy ray-curable oligomer, the adhesive layer is cured by three-dimensional cross-linking when irradiated with an energy ray to reduce the adhesive force and increase the cohesive force. can be prevented from being transferred to the adherend side.

Examples of energy ray-curable compounds include radically polymerizable compounds, cationically polymerizable compounds, and anionically polymerizable compounds. Among them, radically polymerizable compounds are preferred. It has a high curing speed, can be selected from a wide variety of compounds, and can easily control physical properties such as adhesive strength before and after energy ray irradiation.

In the energy ray-curable compound, the number of energy ray-curable functional groups is preferably 2 or more per molecule, more preferably 3 or more per molecule, and 4 per molecule. More preferably, it is more than 5, and it is particularly preferable that it is 5 or more in one molecule. When the number of energy ray-curable functional groups is within the above range, the crosslink density of the pressure-sensitive adhesive layer after energy ray irradiation is sufficient, and desired peelability can be achieved. In addition, it is possible to suppress the occurrence of contamination and adhesive residue due to a decrease in cohesive strength. Moreover, the upper limit of the number of energy ray-curable functional groups is not particularly limited.

Moreover, the energy ray-curable compound may further have a functional group capable of reacting with the cross-linking agent. Examples of such functional groups include hydroxyl groups and carboxyl groups. The energy ray-curable compound reacts with the cross-linking agent and cross-links with the resin (adhesive main agent), thereby further suppressing the occurrence of contamination and adhesive residue.

The energy ray-curable compound is preferably a radically polymerizable oligomer, more preferably a radically polymerizable polyfunctional oligomer. Radically polymerizable oligomers include, for example, those disclosed in JP-A-2012-31316.

Radically polymerizable oligomers and radically polymerizable monomers may be used as the energy ray-curable compound, and among others, radically polymerizable polyfunctional oligomers and radically polymerizable polyfunctional monomers may be used. Examples of the radically polymerizable monomer include those disclosed in JP-A-2010-173091.

Examples of energy ray-curable compounds include (meth)acrylate-based monomers, (meth)acrylate-based oligomers, and (meth)acrylate-based polymers. As the energy ray-curable compound, for example, urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, etc. can also be used.

Moreover, a commercial item may be used for the energy ray-curable compound. For example, Mitsubishi Chemical Corp. urethane acrylate "Shikou UV7620EA (molecular weight: 4100)"; 26000)”, “Artresin UN-951SC (molecular weight: 12500)”, “Artresin UN-952 (molecular weight: 6500-9500)”, “Artresin UN-953 (molecular weight: 14000-40000)”, “Artresin UN-954 (molecular weight: 4200)", "Artresin H-219 (molecular weight: 25000-50000)", "Artresin H-315M (molecular weight: 6600)", "Artresin H-417M (molecular weight: 4000)" ; Acrylic urethane polymer "8BR-600 (molecular weight: 100000)" manufactured by Taisei Fine Chemical Co., Ltd.; Polymer acrylate "Unidic V-6850" manufactured by DIC; Acrylic polymer "SMP-250AP (molecular weight: 20000- 30000)”, “SMP-360A (molecular weight: 20000 to 30000)”; and acrylic resin acrylate “HA7975” manufactured by Showa Denko Materials.

The energy ray-curable compounds may be used alone or in combination of two or more.

Although the weight average molecular weight of the energy ray-curable compound is not particularly limited, it is preferably 30,000 or less, more preferably 10,000, and even more preferably 8,000 or less. If the weight-average molecular weight of the energy ray-curable compound is within the above range, it exhibits sufficient compatibility with the acrylic resin (adhesive main agent), and the adhesive layer exhibits the desired adhesive strength before irradiation with the energy ray. After irradiation, the generation of adhesive residue is suppressed, and the film can be easily peeled off. On the other hand, the weight average molecular weight of the energy ray-curable resin composition can be, for example, 100 or more.

The content of the energy ray-curable compound is, for example, preferably 5 parts by mass or more and 150 parts by mass or less, and preferably 20 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the resin (adhesive main agent). More preferably, it is 30 parts by mass or more and 100 parts by mass or less. When the content of the energy ray-curable compound is within the above range, the crosslink density of the adhesive layer after energy ray irradiation is sufficient, and desired peelability can be achieved. In addition, it is possible to suppress the occurrence of contamination and adhesive residue due to a decrease in cohesive strength.

(3) Polymerization Initiator The adhesive layer can contain a polymerization initiator in addition to the resin (main adhesive) and the energy ray-curable compound.

A general photopolymerization initiator can be used as the polymerization initiator. Specific examples include acetophenones, benzophenones, α-hydroxyketones, benzyl methyl ketals, α-aminoketones, and bisacylphosphine oxides. When urethane acrylate is used as the energy ray-curable compound, the polymerization initiator is preferably a bisacylphosphine-based polymerization initiator. Since this polymerization initiator has heat resistance, when the adhesive composition is applied to the substrate and the energy beam is irradiated, even if the energy beam is irradiated through the substrate, the energy beam can be reliably Curable compounds can be cured.

The polymerization initiator preferably has absorption at a wavelength of 230 nm or more, and preferably has absorption at a wavelength of 300 nm or more and 400 nm or less. Such a polymerization initiator can absorb wide energy rays with a wavelength of 300 nm or more and efficiently generate active species that induce a polymerization reaction of the energy ray-curable compound. Therefore, the energy ray-curable compound can be efficiently cured even with a small amount of energy ray irradiation, and can be easily peeled off. As will be described later, a resin or the like can be used as the base material, and many resins absorb energy rays with a wavelength of up to about 300 nm, but transmit energy rays with a wavelength of about 300 nm or more. Furthermore, in recent years, LED lamps with a wavelength of 300 nm or more are often used in energy beam irradiation devices. Therefore, by using a polymerization initiator having absorption at a wavelength of 230 nm or more, the energy ray-curable compound can be cured using the energy ray that has passed through the substrate.

The content of the polymerization initiator is, for example, preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to a total of 100 parts by mass of the resin (main adhesive) and the energy ray-curable compound, and 0.3 parts by mass. Part or more and 6 parts by mass or less is more preferable. If the content of the polymerization initiator is less than the above range, the polymerization reaction of the energy ray-curable compound will not occur sufficiently, and the adhesive strength of the adhesive layer after energy ray irradiation will become excessively high, making it difficult to achieve peelability. Sometimes you can't. On the other hand, if the content of the polymerization initiator exceeds the above range, the cohesive force is lowered, which may cause contamination and adhesive residue.

(4) Cross-linking agent The adhesive layer can contain a cross-linking agent in addition to the resin (main adhesive agent) and the energy ray-curable compound.

The cross-linking agent is not particularly limited as long as it cross-links at least between the resins (adhesive main agent), and can be appropriately selected according to the type of the resin (adhesive main agent). , epoxy-based cross-linking agents, metal chelate-based cross-linking agents, and the like. Specific examples of isocyanate-based cross-linking agents and epoxy-based cross-linking agents include those disclosed in JP-A-2012-31316. A crosslinking agent can be used individually or in combination of 2 or more types.

The content of the cross-linking agent can be appropriately set according to the type of the cross-linking agent. and more preferably 0.01 parts by mass or more and 10 parts by mass or less. If the content of the cross-linking agent is less than the above range, the adhesion may be poor, or cohesive failure may occur in the adhesive layer when the adherend is peeled off or transferred, resulting in adhesive residue. On the other hand, if the content of the cross-linking agent exceeds the above range, the cross-linking agent remains as an unreacted monomer in the adhesive layer after irradiation with the energy beam, causing contamination and adhesive residue due to a decrease in cohesive force. Sometimes.

(5) Additives The adhesive layer may contain various additives as necessary. Additives include, for example, tackifiers, antistatic agents, plasticizers, silane coupling agents, metal chelating agents, surfactants, antioxidants, ultraviolet absorbers, colorants, preservatives, antifoaming agents, wetting agents, property modifiers, adhesion modifiers, and the like.

The ΔE ^* _ab can be controlled by adjusting the glass transition temperature of the additive. Specifically, as described above, ΔE ^* _ab can be reduced by increasing the glass transition temperature of the additive. The glass transition temperature of the additive is not particularly limited. When the glass transition temperature of the additive is within the above range, the ΔE ^* _ab can be easily adjusted to fall within the predetermined range. When the adhesive layer contains additives, the glass transition temperature of at least one additive is preferably within the above range.

In addition, ΔE ^* _ab can be controlled by adjusting the molecular weight of the additive. Specifically, as described above, ΔE ^* _ab can be reduced by increasing the molecular weight of the additive. Although the weight average molecular weight of the additive is not particularly limited, it may be, for example, 100 or more and 200,000 or less, or 500 or more and 300,000 or less.

In addition, the adhesive layer may contain an adhesive force modifier as described above. Examples of adhesive strength modifiers include acrylic block copolymers and polyester resins. Examples of acrylic block copolymers include Clarity series manufactured by Kuraray Co., Ltd. "LA3320 (Mw: about 115000)", etc.). As the polyester resin, for example, Toyobo's Vylon series (e.g., "Vylon 200 (Mn: about 17000)", "Vylon 600 (Mn: about 16000)", etc.), Unitika's Elitel series ( "Elitel UE3210 (Mw: about 20000)", "Elitel UE9200 (Mw: about 15000)", etc.).

In addition, ΔE ^* _ab can be controlled by adjusting the content of the additive. Specifically, when the additive has a large molecular weight, the ΔE ^* _ab can be reduced by reducing the content of the additive. The content of the additive is appropriately adjusted.

(6) Thickness of Adhesive Layer and Method of Forming The thickness of the adhesive layer may be any thickness that provides sufficient adhesive strength and allows energy rays to penetrate to the inside, for example, 3 μm. 50 μm or more, preferably 5 μm or more and 40 μm or less.

As a method for forming the adhesive layer, for example, a method of applying an adhesive composition on a substrate, a method of applying an adhesive composition on a separator to form an adhesive layer, and a method of bonding the adhesive layer and the substrate together. is mentioned.

3. Substrate The substrate in the present disclosure is a member that supports the adhesive layer.

The substrate is not particularly limited, but it is preferable to reduce the adhesive strength of the adhesive layer by irradiating the adhesive layer from the substrate side of the adhesive tape for semiconductor processing to cure the adhesive layer. is preferably permeable to energy rays.

The Young's modulus of the substrate may be, for example, 2000 MPa or less, 1000 MPa or less, or 700 MPa or less. The Young's modulus of the base material is, for example, preferably 20 MPa or higher, more preferably 30 MPa or higher, and even more preferably 40 MPa or higher. Among others, the substrate is preferably expandable. If the Young's modulus of the base material is too low, the base material becomes extremely soft, which may make it difficult to spread the pressure-sensitive adhesive tape for semiconductor processing uniformly.

Here, the Young's modulus of the substrate can be measured according to JIS K7127. Specific measurement conditions are shown below.
・ Specimen: Specimen type 5
・Distance between chucks: 60 mm
・ Tensile speed: 100mm/min
As a tensile tester, for example, "Tensilon RTF1150" manufactured by A&D Co., Ltd. can be used.

The material of the substrate preferably satisfies the above properties, and examples thereof include low-density polyethylene, high-density polyethylene, polypropylene, polybutene, polymethylpentene, polybutadiene, ethylene-vinyl acetate copolymer, ionomer resin, and ethylene. Olefin resins such as (meth)acrylic acid copolymers and ethylene (meth)acrylic acid ester copolymers; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; polyester resins such as polyethylene terephthalate and polybutylene terephthalate ; urethane resin; polystyrene resin; polycarbonate resin; Examples of materials for the substrate include thermoplastic elastomers such as olefin elastomers, vinyl chloride elastomers, polyester elastomers, styrene elastomers, urethane elastomers, acrylic elastomers, and amide elastomers; isoprene rubber, butadiene rubber. , styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, urethane rubber, and polysulfide rubber. These may be used singly or in combination of two or more.

Among them, olefin resins, polyester resins, and vinyl chloride resins are preferred. That is, the substrate preferably contains an olefinic resin, a polyester resin, or a vinyl chloride resin. Since the vinyl chloride resin is softened by adding a plasticizer, the use of a so-called soft vinyl chloride resin enables the substrate to have no yield point as will be described later. On the other hand, unlike vinyl chloride resins, olefin resins and polyester resins do not contain a large amount of plasticizer, so the content of additives can be reduced, and the ΔE ^* _ab tends to be small. .

Examples of vinyl chloride resins include polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, and vinyl chloride-propylene copolymer. , vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile terpolymer Copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-maleic acid ester copolymer Chlorine-containing resins such as coalescence, vinyl chloride-methacrylate copolymers, vinyl chloride-acrylonitrile copolymers, vinyl chloride-various vinyl ether copolymers; mixtures of these chlorine-containing resins; Mixtures with chlorine-free resins, block copolymers, graft copolymers, and the like can be mentioned. Other chlorine-free resins include, for example, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene terpolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl (meth)acrylate copolymer, polyester etc.

The substrate optionally contains various additives such as plasticizers, fillers, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, flame retardants, colorants, and the like. good too.

In addition, ΔE ^* _ab can be controlled by adjusting the molecular weight of the additive. Specifically, ΔE ^* _ab can be reduced by increasing the molecular weight of the additive. The molecular weight of the additive is appropriately adjusted.

In addition, ΔE ^* _ab can be controlled by adjusting the content of the additive. Specifically, when the additive has a small molecular weight, the ΔE ^* _ab can be reduced by reducing the content of the additive. The content of the additive is appropriately adjusted. For example, when the substrate contains a vinyl chloride resin, the ΔE ^* _ab can be reduced by reducing the content of the plasticizer.

The substrate may be, for example, a single layer or multiple layers.

The adhesive layer side surface of the base material may be surface-treated in order to improve the adhesiveness with the adhesive layer. The surface treatment is not particularly limited, and examples thereof include corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, alkali treatment and the like.

The thickness of the substrate is not particularly limited, and may be, for example, 20 μm or more and 500 μm or less, may be 40 μm or more and 350 μm or less, or may be 50 μm or more and 200 μm or less. If the thickness of the substrate is within the above range, the substrate can be easily expanded and has sufficient strength to prevent breakage.

4. Other Configurations The adhesive tape for semiconductor processing of the present disclosure can have other configurations, if necessary, in addition to the substrate and adhesive layer described above.

The adhesive tape for semiconductor processing of the present disclosure may have a separator on the surface of the adhesive layer opposite to the substrate. The separator can protect the adhesive layer.

Further, the adhesive tape for semiconductor processing of the present disclosure may have a primer layer between the substrate and the adhesive layer. The primer layer can enhance the adhesion between the substrate and the adhesive layer. In addition, the primer layer can prevent the components contained in the base material from migrating to the adherend via the adhesive layer, and as a result, the above ΔE ^* _ab can be reduced. Above all, when the base material contains a vinyl chloride resin, it is preferable that a primer layer is arranged between the base material and the adhesive layer.

5. Application The adhesive tape for semiconductor processing of the present disclosure can be suitably used as an adhesive tape that temporarily fixes or protects components, such as a dicing tape or a back grind tape.

2A to 2E are process diagrams showing an example of a semiconductor manufacturing method using a semiconductor processing adhesive tape, in which the semiconductor processing adhesive tape is used as a dicing tape. First, as shown in FIG. 2(a), a wafer 11 having a circuit formed thereon is attached to an adhesive tape 10 for semiconductor processing, and then, as shown in FIG. 2(b), the wafer 11 having a circuit formed thereon is attached. A dicing process for cutting (dicing) into chips 12 is performed. Next, as shown in FIG. 2(c), an expanding step is performed in which the semiconductor processing adhesive tape 10 is stretched to widen the gap between the chips 12. Next, as shown in FIG. Next, although not shown, the energy ray-curable adhesive layer 2 of the adhesive tape 10 for semiconductor processing is irradiated with an energy ray to be cured to reduce the adhesive strength, and as shown in FIG. 12 is separated from the adhesive tape 10 for semiconductor processing, and a pick-up step of picking up the chip 12 is performed. Next, as shown in FIG. 2(e), a mounting (die bonding) step is performed to bond the picked-up chip 12 to the substrate 30. Next, as shown in FIG.

FIGS. 3A to 3D are process diagrams showing another example of a semiconductor manufacturing method using the adhesive tape for semiconductor processing, in which the adhesive tape for semiconductor processing is used as a dicing tape. First, as shown in FIG. 3(a), a wafer 11 having a circuit formed thereon is attached to an adhesive tape 10 for semiconductor processing, and then, as shown in FIG. A dicing process for cutting (dicing) into chips 12 is performed. Next, as shown in FIG. 3C, a transfer tape 40 is attached to the surface of the chip 12 opposite to the adhesive tape 10 for semiconductor processing. Energy rays are applied to the radiation-curing adhesive layer 2 to cure it, thereby reducing the adhesive force. As shown in FIG. is transferred to the transfer tape 40 .

Note that the present disclosure is not limited to the above embodiments. The above embodiment is an example, and any device that has substantially the same configuration as the technical idea described in the claims of the present disclosure and produces the same effect is the present invention. It is included in the technical scope of the disclosure.

Examples and comparative examples are given below to further illustrate the present disclosure.

[material]
Materials used for the pressure-sensitive adhesive composition are shown below.
・ Adhesive main agent A (acrylic acid ester copolymer, weight average molecular weight about 500,000, solid content 23%)
・ Adhesive main agent B (acrylic acid ester copolymer, weight average molecular weight of about 800,000, solid content of 20%)
・Urethane acrylate A (ultraviolet curable compound, 10-functional, molecular weight 500-1300)
・Urethane acrylate B (ultraviolet curable compound, 9-functional, molecular weight 4100, effective content 65%)
・Urethane acrylate C (ultraviolet curable compound, hexafunctional, molecular weight 4200, effective content 60%)
・Polymerization initiator ("Omnirad 819" manufactured by IGM Resins)
· Cross-linking agent A (isocyanate-based curing agent (tolylene diisocyanate (TDI)-based adduct type (trimethylolpropane adduct)), solid content 75%)
・Crosslinking agent B (epoxy curing agent)
・Crosslinking agent C (metal chelate curing agent)
・ Adhesion adjuster A (acrylic block copolymer (methyl methacrylate-butyl acrylate-methyl methacrylate triblock copolymer), weight average molecular weight of about 65000)
・ Adhesion adjuster B (acrylic copolymer)

[Example 1]
In solid content ratio, 100 parts by mass of the adhesive main agent A, 50 parts by mass of the urethane acrylate A, 3 parts by mass of the cross-linking agent A, and 1.5 parts by mass of the polymerization initiator, a mixed solvent of methyl ethyl ketone and toluene (mixing ratio 1 : 1) was diluted to a solid content of 25% and sufficiently dispersed to prepare an adhesive composition.

On a polyethylene terephthalate (PET) separator that has been subjected to release treatment, the adhesive composition is applied so that the thickness after drying is 10 μm, and dried in an oven at 110 ° C. for 3 minutes to form an adhesive layer. formed.

Next, after laminating a base material (polyethylene terephthalate (PET) film, "TA051" manufactured by Toyobo Co., Ltd., thickness 50 μm) on the adhesive layer, aging is performed at 50 ° C. for 3 days to form an adhesive tape for semiconductor processing. made.

[Example 2]
In the same manner as in Example 1, except that the adhesive composition was prepared as follows, the thickness of the adhesive layer was 20 μm, and the following substrate was used. A tape was made.

In solid content ratio, 100 parts by mass of adhesive main agent B, 40 parts by mass of urethane acrylate B, 30 parts by mass of urethane acrylate C, 0.35 parts by mass of cross-linking agent B, 0.2 parts by mass of cross-linking agent C, and polymerization 6 parts by mass of the initiator and 0.5 parts by mass of the adhesive strength modifier A are diluted with a mixed solvent of methyl ethyl ketone and toluene (mixing ratio 1:1) so that the solid content is 25%, and sufficiently dispersed. , to prepare an adhesive composition.

In addition, a resin composition containing 70 parts by mass of vinyl chloride resin, 25 parts by mass of a plasticizer, and 0.3 parts by mass of nonylphenol was used as the base material, and a film was formed by a calendering method to obtain a polyimide film having a thickness of 90 μm. A vinyl chloride (PVC) film was made.

[Example 3]
In the same manner as in Example 1, except that the adhesive composition was prepared as follows, the thickness of the adhesive layer was 20 μm, and the following substrate was used. A tape was made.

The solid content ratio is 100 parts by mass of the adhesive main agent B, 75 parts by mass of the urethane acrylate A, 0.35 parts by mass of the cross-linking agent B, 7.5 parts by mass of the polymerization initiator, and 40 parts by mass of the adhesive force adjuster A. , and 40 parts by mass of the adhesive strength adjusting agent B were diluted with a mixed solvent of methyl ethyl ketone and toluene (mixing ratio 1:1) so that the solid content was 25%, and sufficiently dispersed to prepare an adhesive composition. .

In addition, a resin composition containing 70 parts by mass of vinyl chloride resin, 25 parts by mass of a plasticizer, and 0.3 parts by mass of nonylphenol was used as the base material, and a film was formed by a calendering method to obtain a polyimide film having a thickness of 70 μm. A vinyl chloride (PVC) film was made.

[Example 4]
Same as Example 1 except that the thickness of the adhesive layer was set to 30 μm and a polyethylene (PE) film ("Esmer VPM-S" manufactured by Nihon Matai Co., Ltd., thickness 100 μm) was used as the base material. Then, an adhesive tape for semiconductor processing was produced.

[Comparative Example 1]
In the same manner as in Example 1, except that the adhesive composition was prepared as follows, the thickness of the adhesive layer was 20 μm, and the following substrate was used. A tape was made.

The solid content ratio is 100 parts by mass of the adhesive main agent B, 75 parts by mass of the urethane acrylate A, 0.35 parts by mass of the cross-linking agent B, 7.5 parts by mass of the polymerization initiator, and 40 parts by mass of the adhesive force adjuster A. , and 40 parts by mass of the adhesive strength adjusting agent B were diluted with a mixed solvent of methyl ethyl ketone and toluene (mixing ratio 1:1) so that the solid content was 25%, and sufficiently dispersed to prepare an adhesive composition. .

A resin composition containing 70 parts by mass of a vinyl chloride resin, 40 parts by mass of a plasticizer, and 0.5 parts by mass of a stabilizer was used as a base material, and a film was formed by a casting method to a thickness of 70 μm. A polyvinyl chloride (PVC) film was made.

[Comparative Example 2]
A pressure-sensitive adhesive tape for semiconductor processing was produced in the same manner as in Example 1, except that the thickness of the pressure-sensitive adhesive layer was 20 μm and the following base material was used.

A resin composition containing 70 parts by mass of a vinyl chloride resin, 40 parts by mass of a plasticizer, and 0.5 parts by mass of a stabilizer is used as a base material, and a film is formed by a casting method to form a polychlorinated film having a thickness of 70 μm. A vinyl (PVC) film was made.

[evaluation]
(1) Color difference ΔE ^* _ab
First, the adhesive tape for semiconductor processing was cut into a size of 40 mm or more in width and 100 mm or more in length. In addition, the glossy surface of a copper foil (“RCF-T5B” manufactured by Fukuda Metal Foil & Powder Co., Ltd., thickness 35 μm) was wiped with isopropyl alcohol (IPA) and dried sufficiently. Next, in an environment where the temperature is 25 ° C. ± 5 ° C., the humidity is 40% RH to 60% RH, and the ultraviolet rays are blocked, the separator of the adhesive tape for semiconductor processing is peeled off to expose the adhesive layer. The surface of the adhesive layer of No. 2 was laminated to the glossy surface of the copper foil by reciprocating it twice with a 2 kg roller to obtain a laminate. Next, the laminate was stored for 6 days in an environment with a temperature of 25° C.±5° C., a humidity of 40% RH or more and 50% RH or less, and shielded from ultraviolet rays. Next, from the side of the adhesive tape for semiconductor processing of the laminate, ultraviolet rays were irradiated so that the integrated light amount was 500 mJ/cm ² to cure the adhesive layer. Next, the adhesive tape for semiconductor processing was peeled off from the laminate at a peel speed of 300 mm/min.

In accordance with JIS Z8722, using a spectrophotometer ("Spectrophotometer SE6000" manufactured by Nippon Denshoku Industries Co., Ltd.), the surface of the copper foil before lamination of the adhesive tape for semiconductor processing and after peeling the adhesive tape for semiconductor processing The lightness L ^* , chromaticities a ^* and b ^* of the adherend surface of the copper foil were measured to obtain ΔE ^* _ab . The measurement conditions were D65 light source, 10° field of view, and reflection measurement. At this time, when measuring the color of the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing, the adherend surface of the copper foil was wiped with isopropyl alcohol, dried sufficiently, and then measured.

(2) Wettability The wettability was confirmed for the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adherend surface of the copper foil after peeling of the adhesive tape for semiconductor processing. Specifically, using a dyne pen (“EnerDyne dyne pen Variety” manufactured by enercon), a line was drawn on the surface of the copper foil to be adhered, and left to stand for 5 seconds. When the ink was retained, it was determined that there was wettability, and when the ink was repelled, it was determined that there was no wettability. The dyne numbers of the dyne pens were 30, 38, and 48.

Regarding the adherend surface of the copper foil before lamination of the pressure-sensitive adhesive tape for semiconductor processing, all of the three types of Dyne pens were judged to have wettability.

The wettability of the adherend surface of the copper foil after the peeling of the pressure-sensitive adhesive tape for semiconductor processing was evaluated according to the following criteria.
A: All three types of dyne pens were judged to have wettability.
B: Of the 3 types of dyne pens, 2 types of dyne pens were judged to have wettability, and 1 type of dyne pen was judged to have no wettability.
C: Of the three types of dyne pens, two or more types of dyne pens were determined to have no wettability.

(3) Adhesive strength to SUS plate Adhesive strength to SUS plate is determined by test method 1 of JIS Z0237: 2009 (adhesive tape/adhesive sheet test method) (temperature 23 ° C humidity 50% RH, tape and sheet on stainless steel test plate Measured by peeling the test piece in the length direction under the conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm/min. The SUS plate used was SUS304, surface finish BA, thickness 1.5 mm, width 100 mm, length 150 mm.

(4) Adhesion to SUS Plate after Energy Beam Irradiation First, the surface of the adhesive tape for semiconductor processing on the substrate side was irradiated with ultraviolet rays so that the cumulative amount of light was 500 mJ/cm ² to cure the adhesive layer. The adhesive strength of the adhesive tape for semiconductor processing after UV irradiation to the SUS plate is determined according to JIS Z0237:2009 (adhesive tape/adhesive sheet test method) test method method 1 (temperature 23 ° C humidity 50% RH, tape and sheet stainless steel Test method of peeling off at 180° to a test plate), the test piece was peeled off in the longitudinal direction under the conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm/min. The SUS plate used was SUS304, surface finish BA, thickness 1.5 mm, width 100 mm, length 150 mm.

In the adhesive tapes for semiconductor processing of Examples 1 to 4, the color difference ΔE ^* _ab is within a predetermined range, and the wettability of the adherend surface of the copper foil after peeling the adhesive tape for semiconductor processing is higher than the wettability of the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing. It was confirmed that there was almost no change. On the other hand, in the adhesive tapes for semiconductor processing of Comparative Examples 1 and 2, the color difference between the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adherend surface of the copper foil after peeling of the adhesive tape for semiconductor processing. ΔE ^* _ab does not satisfy the predetermined range, and the wettability of the adherend surface of the copper foil before lamination of the adhesive tape for semiconductor processing is compared with the adhesion of the copper foil after peeling the adhesive tape for semiconductor processing. The wettability of the surface changed.

Moreover, according to Examples 2 and 3, the above ΔE ^* _ab does not necessarily correlate with the wettability. This suggests that the ΔE ^* _ab can capture changes in the surface state of the copper foil that could not be captured by wettability.

DESCRIPTION OF SYMBOLS 1... Base material 2... Adhesive layer 10... Adhesive tape for semiconductor processing

Claims (3)

An adhesive tape for semiconductor processing, comprising a substrate and an energy ray-curable adhesive layer disposed on one surface of the substrate,
The adhesive layer contains a (meth)acrylic acid ester copolymer as an adhesive base agent and urethane (meth)acrylate as an energy ray-curable compound,
An adhesive tape for semiconductor processing, having a color difference ΔE ^* _ab of 2.0 or less in the L ^* a ^* b ^* color system, determined by the following test.
Test: It has the following steps (1) to (5) in order.
(1) The surface of the adhesive layer of the adhesive tape for semiconductor processing is attached to a copper foil to prepare a laminate.
(2) The laminate is stored for 6 days in an environment where the temperature is 25° C.±5° C., the humidity is 40% RH or more and 60% RH or less, and the energy rays are blocked.
(3) The adhesive tape for semiconductor processing of the laminate is irradiated with energy rays to cure the adhesive layer.
(4) Peel off the adhesive tape for semiconductor processing from the laminate.
(5) L ^* a ^* b ^* table of the adhesion surface of the copper foil before lamination of the adhesive tape for semiconductor processing and the adhesion surface of the copper foil after peeling of the adhesive tape for semiconductor processing. Obtain the color difference ΔE ^* _ab in the color system. 2. The pressure-sensitive adhesive tape for semiconductor processing according to claim 1, wherein the pressure-sensitive adhesive tape for semiconductor processing has an adhesive strength of 1 N/25 mm or more to a SUS plate before irradiation with energy rays. 3. The pressure-sensitive adhesive tape for semiconductor processing according to claim 1, wherein the adhesive strength to a SUS plate after energy beam irradiation is 2 N/25 mm or less.

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