KR20230008393A - Double-sided adhesive film and the method for peeling double-sided adhesive film - Google Patents

Abstract

The present invention relates to a double-sided adhesive film and a method for removing a double-sided adhesive film, wherein the double-sided adhesive film comprises: a first adhesive layer formed with a first adhesive composition and disposed on a first surface of a double-sided adhesive sheet; and a second adhesive layer formed with a second adhesive composition and disposed on a second surface which is a back surface of the first surface, the first adhesive composition includes a polymer and a first photoinitiator, and the first photoinitiator has an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1 % and is included in an amount of 0.5-5 parts by weight with respect to 100 parts by weight of the polymer. The double-sided adhesive sheet is selectively removed from a wafer and a carrier glass so that the double-sided adhesive sheet can be removed cleanly without causing damage to the wafer and the carrier glass.

Description

Double-sided adhesive sheet and double-sided adhesive sheet peeling method {DOUBLE-SIDED ADHESIVE FILM AND THE METHOD FOR PEELING DOUBLE-SIDED ADHESIVE FILM}

The present invention relates to a double-sided adhesive sheet and a method for peeling the double-sided adhesive sheet.

For miniaturization of portable electronic devices, thinning of semiconductor chips is required. In order to thin the semiconductor chip, a backside thin film grinding and dicing process is required for the semiconductor wafer, and an adhesive film is used to protect and/or fix the wafer in the grinding and dicing process. do. In addition, the need for a double-sided pressure-sensitive adhesive sheet capable of being adhered to both the wafer and the carrier glass during the process of grinding the back side of the wafer is on the rise.

The double-sided adhesive sheet is adhered to the wafer and carrier glass to protect the wafer during semiconductor wafer processing, and must be removed from the wafer and carrier glass as necessary. Various methods may be used to remove, ie peel, the adhesive sheet from the wafer.

Conventional methods of peeling an adhesive sheet from a wafer include a method of applying heat, a method of irradiating high-pressure mercury ultraviolet (UltraViolet rays), and a method of irradiating LED ultraviolet rays of a specific wavelength. However, if heat or high-pressure mercury ultraviolet rays are irradiated, the wafer may be damaged when the adhesive sheet is peeled off, and in the case of irradiating LED ultraviolet rays of a specific wavelength, the wafer is bent or the residue of the adhesive sheet is formed when the adhesive sheet is peeled off. can exist in

Korean Patent Publication No. 10-2018-0086448 and the like discloses a process of peeling a support from a semiconductor wafer, but there is a disadvantage in that the wafer may be damaged by heat as a process of heating the semiconductor wafer and the support is used.

Republic of Korea Patent Publication No. 10-2018-0086448 (published on July 31, 2018)

An object of the present invention is to provide a double-sided pressure-sensitive adhesive sheet and a double-sided pressure-sensitive adhesive sheet peeling method for effectively separating the double-sided pressure-sensitive adhesive sheet from the wafer and the carrier glass to prevent damage to the wafer and to recycle the carrier glass.

In order to achieve the above purpose,

The present invention is formed by the first adhesive composition, the first adhesive layer on the first side of the double-sided adhesive sheet; and a second adhesive layer formed of the second adhesive composition and located on a second surface that is a back surface of the first surface, wherein the first adhesive composition includes a polymer and a first photoinitiator, The first photoinitiator has an absorption coefficient of 0.8 or more at 380 nm at a concentration of 0.1%, and is included in an amount of 0.5 to 5% by weight based on 100 parts by weight of the polymer.

Preferably, the double-sided pressure-sensitive adhesive sheet of the present invention may be a double-sided pressure-sensitive adhesive sheet for semiconductor wafer processing.

In addition, the present invention is a method of peeling a double-sided adhesive sheet adhered to a wafer and a carrier glass, in order to peel the double-sided adhesive sheet from the wafer, a 380 nm LED for lowering the adhesive strength of the first adhesive layer of the double-sided adhesive sheet irradiating ultraviolet rays; and irradiating high-pressure mercury ultraviolet rays to lower the adhesive strength of the second adhesive layer of the double-sided adhesive sheet in order to peel the second adhesive layer of the double-sided adhesive sheet from the carrier glass. A double-sided adhesive sheet peeling method comprising a first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1%, and a second photoinitiator having an extinction coefficient at 380 nm of less than 0.8 at a concentration of 0.1%. to provide.

When used in the double-sided adhesive sheet and the method for peeling the double-sided adhesive sheet according to the present invention, the adhesive sheet can be effectively separated from the wafer and the carrier glass can be recycled.

1A to 1B are diagrams illustrating a peeling method of a double-sided pressure-sensitive adhesive sheet according to an embodiment of the present invention.
2A to 2B are views illustrating a method of manufacturing an adhesive sheet according to an embodiment of the present invention.
3 is a diagram showing the extinction coefficient of the photoinitiator according to the present invention in 0.1% acetone.

The present invention relates to a double-sided pressure-sensitive adhesive sheet, a method for peeling the double-sided pressure-sensitive adhesive sheet, and a method for manufacturing the double-sided pressure-sensitive adhesive sheet. In addition, the present invention includes each of the first adhesive layer and/or the second adhesive layer included in the double-sided adhesive sheet, as well as a composition for preparing them, within the scope of the present invention. In addition, the present invention includes the double-sided adhesive sheet, a peeling method of the double-sided adhesive sheet, a method of manufacturing the double-sided adhesive sheet, and/or a semiconductor wafer manufactured using the first adhesive layer and/or the second adhesive layer, A device including the semiconductor wafer is included.

The semiconductor wafer of the present invention may be ground to a thickness of 100 μm or less, and preferably may be ground to a thickness of 30 μm or less.

Hereinafter, the present invention will be described in detail.

Throughout this specification, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

When it is said that a certain part "includes" a certain component throughout this specification, it means that it may further include other components, not excluding other components unless otherwise stated.

Hereinafter, examples will be described in detail to explain the present invention in detail. However, the embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

<Adhesive Sheet>

The double-sided adhesive sheet 100 according to the present invention includes a first adhesive layer 110 and a second adhesive layer 120. At this time, the first adhesive layer 110 and the second adhesive layer 120 may be previously adhered through a predetermined process.

First adhesive layer (110)

The first adhesive layer 110 according to the present invention is formed of the first adhesive composition and may be provided on the first side of the double-sided adhesive sheet 100 . For example, the first surface of the double-sided adhesive sheet 100 may be the upper surface of the double-sided adhesive sheet 100, but is not limited thereto.

The first adhesive layer 110 is formed by a first adhesive composition having adhesive strength, and the first adhesive layer 110 may be adhered to a semiconductor wafer for semiconductor wafer processing, but is not limited thereto, and the first adhesive layer 110 is not limited thereto. 110 may be attached to a carrier glass for fixing the semiconductor wafer during back grinding (back grinding) of the semiconductor wafer.

The first adhesive layer 110 according to an embodiment of the present invention may have characteristics of an ultraviolet curable adhesive. Since the UV-curable adhesive has a different curing reactivity depending on the wavelength of the irradiated UV light, by changing the configuration of the first adhesive composition forming the first adhesive layer 110, the high-pressure mercury UV light or LED UV light is selectively applied. The adhesive strength of the first adhesive layer 110 may be reduced by using the adhesive. Here, the high-pressure mercury ultraviolet is a mercury lamp in which the gas pressure in the lamp tube is increased to emit high ultraviolet rays, and has a characteristic having a wavelength range from 254 nm to 436 nm.

The first adhesive composition of the first adhesive layer 110 according to an embodiment of the present invention may be determined such that the adhesive strength of the first adhesive layer 110 can be reduced by irradiation of LED ultraviolet rays of a predetermined wavelength. The predetermined wavelength LED may have a wavelength of 360 nm to 400 nm.

At this time, the first adhesive composition of the first adhesive layer 110 should be determined so that no residue of the first adhesive layer 110 remains on the surface of the wafer when the double-sided adhesive sheet 100 is separated from the wafer.

For example, the first adhesive layer 110 is formed by a first adhesive composition, the first adhesive composition includes a polymer and a first photoinitiator, and the first photoinitiator has a 380 nm wavelength at a concentration of 0.1%. The absorption coefficient of is 0.8 or more, and may be included in 0.5 to 5% by weight compared to 100 parts by weight of the polymer.

An acrylic composition or a siloxane composition may be included as the polymer.

In this case, the first photoinitiator may include only one kind, but is not limited thereto, and at least two or more kinds of photoinitiators having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1% may be mixed and used.

Specifically, the first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1% may have an extinction coefficient of 0.8 or more when the absorption coefficient of 380 nm wavelength is measured in a solution containing 0.1% in solvent acetone. In this case, 380 nm It can accelerate the curing reaction by LED UV, and for the same reason, when applying the peeling process of the double-sided adhesive tape, it is possible to secure the characteristics of selective peeling by 380nm. Therefore, when securing the peeling process, there is an advantage of being able to select various options. On the other hand, since the curing process using the long wavelength among UV wavelengths is applied, the long wavelength can penetrate to the deepest part when UV irradiation on the carrier glass side. Therefore, there is also an advantage of preventing uncuring of the first adhesive layer. For this reason, it is preferable that the 380 nm extinction coefficient is 0.8 or more.

The first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at the concentration of 0.1% may be a phosphinoxide-based photoinitiator, and an acetophenone-based photoinitiator is preferable in that it satisfies an extinction coefficient of 0.8 or more at 380 nm.

For example, the first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1% of the present invention is a commercial product, and Irhacure TPO, Irgacure 369, Irgacure 819 (BASF), etc. may be used, but is not limited thereto.

When the first photoinitiator is included in an amount of less than 0.5 parts by weight based on 100 parts by weight of the polymer, an appropriate change in adhesive strength cannot be induced after curing, and a high level of adhesive strength can be maintained due to insufficient reduction in adhesive strength. In this case, there is a problem that can cause damage to the wafer during the tape removal process, and if it is included in excess of 5 parts by weight, it is added in excess compared to the polymer, resulting in cost loss of raw materials primarily, and unreacted due to the excessively added photoinitiator A photoinitiator may precipitate as a foreign substance. In addition, since a large amount of photoinitiator having a high absorbance of 380 nm is included, it is not preferable because it may cause performance change due to visible light during storage after commercialization.

For example, the first adhesive composition forming the first adhesive layer 110 will be described in more detail. The first adhesive composition includes a polymer and a first photoinitiator, and is selected from a crosslinking agent/curing agent and an additive. The above may further be included, and in this case, the content of the first photoinitiator may be 0.5 to 5 parts by weight based on 100 parts by weight of the polymer.

The thickness of the first adhesive layer 110 according to an embodiment of the present invention may be 60 to 120 μm, but is not limited thereto. When the thickness of the first adhesive layer is 60 μm or less, the ability to cover irregularities that can be bonded to the first adhesive layer may be insufficient. In addition, when the thickness of the first adhesive layer rises to 120 μm or more, the adhesive force becomes higher than the required level, obstructing the necessary peeling process. In addition, a certain level of thickness management is necessary because it is advantageous to the grinding process when the total thickness of the wafer and adhesive tape is constantly managed.

The first adhesive layer 110 according to the present embodiment is adhered to the wafer during the backside grinding process of the wafer, and after the backside grinding process of the wafer, the double-sided adhesive sheet 100 is irradiated with LED ultraviolet light having a predetermined wavelength, so that both sides of the wafer are removed from the wafer. The adhesive sheet 100 may be peeled off. At this time, the LED ultraviolet light of a predetermined wavelength may be 380 nm, but is not limited thereto, and may be 360 nm to 400 nm.

Accordingly, the double-sided adhesive sheet 100 according to the present embodiment can be used to protect and fix the wafer during the backside grinding process of the wafer, and after the backside grinding process is finished, the double-sided adhesive sheet 100 can be irradiated with LED ultraviolet rays. can be removed neatly from the wafer. For peeling of the double-sided adhesive sheet 100, since LED ultraviolet light is used instead of high-pressure mercury ultraviolet light, damage to the wafer due to heat and ozone generated when high-pressure mercury ultraviolet light is used can be prevented.

Second adhesive layer (120)

The second adhesive layer 120 according to the present invention is formed of the second adhesive composition and may be provided on the second side of the double-sided adhesive sheet 100 . For example, the second side of the double-sided adhesive sheet 100 is the back side of the first side of the double-sided adhesive sheet 100 on which the first adhesive layer 110 is formed. It may be the lower side of, but is not limited thereto.

The second adhesive layer 120 is formed by a second adhesive composition having adhesive strength, and the second adhesive layer 120 may be adhered to a carrier glass to fix the wafer during the process of grinding the back side of the wafer, but is not limited thereto. , the second adhesive layer 120 may be adhered to the wafer.

The second adhesive layer 120 according to an embodiment of the present invention may have UV curable adhesive characteristics as in the first adhesive layer 110, and overlapping descriptions are omitted, but in the first adhesive layer 110 The characteristics of the UV curable adhesive described above may also be applied to the second adhesive layer 120 .

The second adhesive composition of the second adhesive layer 120 according to an embodiment of the present invention may be determined such that the adhesive strength of the second adhesive layer 120 can be reduced by high-pressure mercury ultraviolet irradiation. In addition, the second adhesive composition of the second adhesive layer 120 should be determined so that no residue of the second adhesive layer 120 remains on the surface of the carrier glass when the double-sided adhesive sheet 100 is separated from the carrier glass. .

For example, the second adhesive layer 120 is formed by a second adhesive composition, and the second adhesive composition includes a polymer and a second photoinitiator, and the second photoinitiator has a 380 nm wavelength at a concentration of 0.1%. The extinction coefficient of is less than 0.8, and may be included in 0.5 to 5 parts by weight compared to 100 parts by weight of the polymer.

The polymer may be the same as or different from the polymer of the first adhesive composition.

At this time, only one type of second photoinitiator may be included, but is not limited thereto, and at least two or more types of photoinitiators having an extinction coefficient of less than 0.8 at 380 nm at a concentration of 0.1% may be used in combination.

The second photoinitiator having an extinction coefficient of less than 0.8 at 380 nm at a concentration of 0.1% is, in detail, measured in a solution containing 0.1 wt% of the photoinitiator in solvent acetone. In the present invention, when the UV curing adhesive layer having a low absorption coefficient of 380 nm comes to the second adhesive layer, curing by 380 nm LED UV curing the first adhesive layer does not occur. In this case, there is an advantage in that the first adhesive layer can be selectively peeled off. In addition, since the second adhesive layer can induce curing under UV curing conditions of 360 nm or less, it has the advantage of being free from peeling through an additional process. In addition, when UV radiation is applied to the surface of the carrier glass on which the second adhesive layer exists, insufficient curing of the adhesive layer does not occur because sufficient curing is possible with a short wavelength of UV 360 nm or less. Because of these structural characteristics, it is preferable that the 380 nm extinction coefficient is less than 0.8.

The second photoinitiator having an extinction coefficient of less than 0.8 at 380 nm at a concentration of 0.1% may be an acetophenone-based photoinitiator), and is preferable in that it may satisfy an extinction coefficient of less than 0.8 at 380 nm.

For example, the second photoinitiator having an extinction coefficient of less than 0.8 at 380 nm at a concentration of 0.1% of the present invention is a commercial product, such as Micure CP-4 (Miwon Special Chemical Co.), Irgacure 184, Irgacure 651, Irgacure 907, Irgacure 2959, and Darocur. BP, Darocur MBF (above BASF), etc. may be used, but is not limited thereto.

When the second photoinitiator is included in less than 0.5 parts by weight relative to 100 parts by weight of the polymer, there is a problem in that a sufficient adhesiveness reduction effect is not shown after high-pressure mercury UV radiation for the peeling process. There is a problem that the photoinitiator may be precipitated as a foreign substance, and it is not preferable for the reason that performance degradation may occur during storage after commercialization due to the photoinitiator added in excess.

The second adhesive composition forming the second adhesive layer 120 will be described as an example in more detail. The above may further be included, and at this time, the content of the second photoinitiator may be 0.5 to 5 parts by weight based on 100 parts by weight of the polymer. For example, the second photoinitiator may be CP-4 (I-184), I-819, or a mixture of CP-4 (I-184) and I-819, but is not limited thereto. .

The thickness of the second adhesive layer 120 according to an embodiment of the present invention may be 10 to 50 μm, but is not limited thereto.

If the thickness of the second adhesive layer is less than 10 μm, sufficient adhesive performance cannot be obtained, and if the thickness is greater than 50 μm, the final thickness of the product must be less than 200 μm to be advantageous for equipment input, but the final thickness may be limited. In addition, the fixing force to the carrier glass may be weakened, resulting in wafer damage during the grinding process.

The second adhesive layer 120 according to the present embodiment is adhered to the carrier glass during wafer processing, and after the first adhesive layer 110 is peeled off from the wafer, the double-sided adhesive sheet 100 is irradiated with high-pressure mercury ultraviolet rays. By this, the double-sided adhesive sheet 100 can be peeled from the carrier glass.

Accordingly, by using the double-sided pressure-sensitive adhesive sheet 100 according to the present embodiment, after the wafer is separated from the double-sided pressure-sensitive adhesive sheet 100, high-pressure mercury ultraviolet rays are irradiated to prevent the wafer from being damaged by the high-pressure mercury ultraviolet rays. Also, as the second adhesive layer 120 is cleanly removed from the carrier glass, the carrier glass can be recycled.

Additionally, when the second adhesive layer 120 according to the present embodiment includes a siloxane composition (siloxane resin) rather than an acrylic composition, the second adhesive layer 120 can be physically peeled off by the tackiness of the siloxane composition. For example, the second adhesive layer 120 may not include the second photoinitiator. In this case, in the double-sided adhesive sheet 100, after the first adhesive layer 110 is peeled off from the wafer, the second adhesive layer 120 can be physically peeled off, and the second adhesive layer 120 is separated from the carrier glass. As it is cleanly removed, the carrier glass can be recycled.

Adhesive Sheet (100)

The adhesive sheet 100 according to the present invention is used for semiconductor wafer processing and may include a first adhesive layer 110 and a second adhesive layer 120 . During processing of the wafer 200, the double-sided adhesive sheet 100 may be used to protect and fix the wafer during the backside grinding process. At this time, the first adhesive layer 110 is attached to the wafer and the second adhesive layer 120 is a carrier glass can be adhered to. For example, using the double-sided adhesive sheet 100 according to the present embodiment, a wafer may be ground to a thickness of about 100 μm or less, preferably about 50 μm or less, and more preferably about 30 μm. , but not limited thereto.

The double-sided adhesive sheet 100 according to the present invention may or may not include the first adhesive layer 110, the second adhesive layer 120, and the intermediate layer 130, and in the case of including the intermediate layer 130, the above The intermediate layer 130 may be positioned between the first adhesive layer 110 and the second adhesive layer 120 .

For example, the intermediate layer 130 may include polyimide (PI), polyethylene (PE), polyethylene terephthalate (PET), triacetate cellulose (TAC), and polymethyl methacrylate (PMMA). A resin containing at least one of polymethyl methacrylate), acrylic, and siloxane may be used, but is not limited thereto. Preferably, the intermediate layer 130 of the present invention may include polyimide (PI).

In addition, the intermediate layer 130 according to the present embodiment does not have UV absorbing performance. That is, since the intermediate layer 130 can transmit ultraviolet rays as it is, even if the intermediate layer 130 is included in the double-sided adhesive sheet 110, the process of separating the double-sided adhesive sheet 110 from the wafer and the carrier glass as described above is performed as is. can be applied

Accordingly, the first adhesive composition is applied to the first surface (eg, the upper surface) of the intermediate layer 130 to form the first adhesive layer 110, and the second adhesive composition is applied to the intermediate layer 130. The second adhesive layer 120 may be formed by being applied to the second surface (eg, the lower surface) of the surface. When the intermediate layer 130 is made of PI, the thickness of the intermediate layer 130 may be about 20 to 50 μm, but is not limited thereto.

As described above, as the middle layer 130 is included in the double-sided adhesive sheet 100, the effect of increasing the average CTE of the adhesive sheet can be expected, and the impact resistance during grinding due to the improved physical properties, the first and second adhesive layers The effect of increasing the holding power can be expected. In addition, when an intermediate layer having high heat resistance is selected, the average heat resistance of the pressure-sensitive adhesive sheet has a synergistic effect, so heat resistance during processing and resistance to heat generated by grinding can be improved.

According to one embodiment of the present invention, the double-sided adhesive sheet 100 may be adhered to the wafer 200 and the carrier glass 300, and the double-sided adhesive sheet 100 may be attached to the wafer 200 and the carrier glass 300. may be adhered to.

<Wafer> and <Carrier Glass>

The double-sided adhesive sheet 100 according to the present embodiment may be used when a through-silicon via (TSV) technology is applied to thin the wafer 200 . In more detail, since the carrier glass 300 is required for processing the wafer 200 in order to apply the TSV technology, the double-sided adhesive sheet 100 used in the processing of the wafer 200 prevents vibration of the wafer 200. Suppression and bump protection performance should be secured, and strong fixing force should also be secured to the carrier glass 300 . In addition, after the process of grinding the back side of the wafer 200 is finished, the double-sided adhesive sheet 100 should be selectively separated from the wafer 200 and the carrier glass 300 . As described above, after peeling the double-sided adhesive sheet 100 from the wafer 200 by irradiating 380 nm LED ultraviolet rays, the double-sided adhesive sheet 100 is peeled from the carrier glass 300 by irradiating high-pressure mercury ultraviolet rays. can Accordingly, the carrier glass 300 can be recycled without damaging the wafer 200 by using the double-sided adhesive sheet 100 according to the present embodiment.

<Method of peeling off the adhesive sheet>

In addition, the present invention provides a double-sided adhesive sheet peeling method for peeling the double-sided adhesive sheet from a wafer and a carrier glass.

In the peeling method of the double-sided adhesive sheet, the contents described above may be applied as they are to the contents of the first adhesive layer, the second adhesive layer, the wafer, the carrier glass, and the like.

In the peeling method of the double-sided adhesive sheet of the present invention, the structure and components of the first adhesive layer, the second adhesive layer, the wafer, the carrier glass, etc., and the manufacturing method thereof do not interfere with the technical characteristics described above. , It is not particularly limited, and those known in the art can be employed without limitation.

The method of peeling the double-sided adhesive sheet adhered to the wafer and the carrier glass is to irradiate 380 nm LED ultraviolet light to lower the adhesive strength of the first adhesive layer of the double-sided adhesive sheet in order to peel the double-sided adhesive sheet from the wafer (410) and irradiating the second adhesive layer of the double-sided adhesive sheet with high-pressure mercury ultraviolet rays to lower the adhesive strength of the second adhesive layer of the double-sided adhesive sheet in order to peel the second adhesive layer of the double-sided adhesive sheet from the carrier glass (420). The layer may include a first photoinitiator having an extinction coefficient at 380 nm of 0.8 or greater at a concentration of 0.1%, and the second adhesive layer may include a second photoinitiator having an extinction coefficient at 380 nm of less than 0.8 at a concentration of 0.1%.

In addition, the first adhesive layer is formed from a first adhesive composition, the first adhesive composition includes a polymer and a first photoinitiator, and the first photoinitiator is 0.5 to 5 parts by weight based on 100 parts by weight of the polymer. can be included

In one embodiment of the present invention, the adhesive strength of the first adhesive composition may be smaller than the adhesive strength of the second adhesive composition.

The second adhesive layer is formed from a second adhesive composition, the second adhesive composition includes a polymer and a second photoinitiator, and the second photoinitiator may be included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the polymer. there is.

1A to 1B are diagrams showing a method of peeling a double-sided pressure-sensitive adhesive sheet according to the present invention in more detail. 1A to 1B illustrate the double-sided adhesive sheet 100 of the present invention as an example, but the scope of the present invention is not limited thereto. In addition, FIGS. 1A to 1B illustrate a back surface grinding process of the wafer 200 as an example, but is not limited thereto.

In the present invention, for backside grinding of the wafer 200, the double-sided adhesive sheet 100 is adhered to the wafer 200 and the carrier glass 300. For example, the first adhesive layer 110 of the double-sided adhesive sheet 100 is adhered to the wafer 200, and the second adhesive layer 120 of the double-sided adhesive sheet 100 is adhered to the carrier glass 300. can be sticky. In addition, the double-sided adhesive sheet 100 according to the present invention includes a first adhesive layer 110, a second adhesive layer 120 and an intermediate layer 130, and the intermediate layer 130 comprises the first adhesive layer 110 And it may be located between the second adhesive layer 120.

After the backside grinding process of the wafer 200 is completed, in order to peel the double-sided adhesive sheet 100 from the wafer 200, the first light source 400 may irradiate LED ultraviolet rays of a predetermined wavelength, and thus, As shown in FIG. 1A , while the adhesive force of the first adhesive layer 110 of the double-sided adhesive sheet 100 decreases, the double-sided adhesive sheet 100 may be separated from the wafer 200 . The first light source 400 according to the present embodiment may be an LED lamp for irradiating 380 nm LED ultraviolet light, but is not limited thereto, and may have other wavelength LEDs capable of reducing the adhesive strength of the first adhesive layer 110. It can be a light source to investigate hypocrisy. Accordingly, the double-sided adhesive sheet 100 can be completely separated from the wafer 200, and at this time, the double-sided adhesive sheet 100 separated from the wafer 200 is still adhered to the carrier glass 300. That is, since the first adhesive composition and the second adhesive composition forming each of the first adhesive layer 110 and the second adhesive layer 120 of the double-sided adhesive sheet 100 contain photoinitiators having different characteristics, Irradiation of 380 nm LED ultraviolet light by the first light source 400 may decrease only the adhesive strength of the first adhesive layer 110 .

In order to peel the double-sided adhesive sheet 100 from the carrier glass 300, the second light source 500 may irradiate high-pressure mercury ultraviolet rays. In this case, the second light source 500 may be a high-pressure mercury lamp or a halogen lamp for irradiating high-pressure mercury ultraviolet rays, but is not limited thereto. Accordingly, while the adhesive strength of the second adhesive layer 120 of the double-sided adhesive sheet 100 decreases, the double-sided adhesive sheet 100 can be separated from the carrier glass 300, and the double-sided adhesive sheet can be separated from the carrier glass 300. (100) can be completely separated. As the double-sided adhesive sheet 100 is neatly separated from the carrier glass 300, the carrier glass 300 can be recycled.

<Adhesive composition>

The present invention provides an adhesive composition having adhesive strength to be adhered to and peeled from a wafer and a carrier glass. Hereinafter, a first adhesive composition having adhesive strength for attaching and peeling the double-sided adhesive sheet according to this embodiment to a wafer and a second adhesive composition having adhesive strength for attaching and peeling the double-sided adhesive sheet according to this embodiment to a carrier glass explain in more detail.

< First adhesive composition >

The first adhesive composition according to an embodiment of the present invention includes a polymer and a first photoinitiator, and may further include a crosslinking agent. For example, the first photoinitiator is characterized in that the 380nm extinction coefficient at a concentration of 0.1% is 0.8 or more.

The first photoinitiator may be included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the polymer.

The polymer may be an acrylic composition or an acrylic resin formed therefrom, or may be a siloxane composition or a siloxane resin formed therefrom.

In one embodiment of the present invention, the adhesive strength of the first adhesive composition may be smaller than the adhesive strength of the second adhesive composition, but is not limited thereto.

acrylic composition

Referring to the acrylic composition (acrylic polymer, acrylic resin) according to an embodiment of the present invention as an example, the acrylic composition includes 100 to 120 parts by weight of 2-ethylhexyl acrylate (2-EHAM) and / or an acrylic monomer containing 80 to 100 parts by weight of butyl acrylate (BAM); Contains 10 to 20 parts by weight of 2,3-epoxypropyl methacrylate (GMA), 10 to 20 parts by weight of acrylic acid (AAc) and/or methacrylic acid (mAAc) a cross-linking monomer; An initiator comprising 0.6 to 1.0 parts by weight of 2,2'-azobis (isobutyronitrile) (AIBN) and 0.6 to 1.0 parts by weight of benzoyl peroxide (BPO); Acrylic formed by polymerization of a solvent containing 130 to 180 parts by weight of ethyl acetate (EAC), 60 to 80 parts by weight of methanol (MeOH), and 15 to 20 parts by weight of isopropyl alcohol (IPA) copolymer; And ethyl acetate (ethyl acetate, EAC) 400 to 450 parts by weight; may be made of a mixed transparent mucus, including. At this time, the acrylic composition is characterized in that the solid content of the acrylic copolymer is 30 to 40% by weight (drying at 150 ° C. for 30 minutes) and the viscosity is 2,000 to 3,000 cps (25 ° C.), but is not limited thereto.

cross-linking agent

The crosslinking agent according to an embodiment of the present invention may be an isocyanate-based such as HDI or TDI, an aziridine-based, or the like, and may be included in an amount of 2 to 10 parts by weight compared to the polymer. In more detail, for example, the crosslinking agent may include alkylenediamines having two amino groups and an alkylene group such as ethylenediamine, triethylenediamine, and hexamethylenediamine; Tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropanetolylene diisocyanate adduct, triphenylmethane triisocyanate, methylene bis (4-phenylmethane triisocyanate, isophorone diisocyanate and their ketoxime block water or phenol block water Isocyanates such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, di Epoxies such as glycidylaniline and diglycidylamine; Monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde; Glyoxal, malondialdehyde, succindialdehyde, glutaldialdehyde, maledialdehyde dialdehydes such as phthaldialdehyde, amino-formaldehyde resins such as methylol urea, methylol melamine, alkylated methylol urea, alkylated methylolized melamine, acetguanamine, and condensates of benzoguanamine and formaldehyde. It can be.

The aziridine-based crosslinking agent includes tetramethylol-tri-β-aziridinylpropionate, trimethylol-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, and aziridine-based compounds having two or more aziridinyl groups in the molecule, such as trimethylolpropane-tri-β-(2-methylaziridine)propionate.

First photoinitiator

The first adhesive composition includes a first photoinitiator.

The first adhesive composition according to an embodiment of the present invention requires a photoinitiator having high light absorption performance in a wavelength range around 380nm in order to secure peeling properties in the 380nm LED ultraviolet light. Accordingly, the first adhesive composition according to the present embodiment includes a first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1%, and the first photoinitiator is 0.4 or more 5 parts by weight based on 100 parts by weight of the polymer included together. part, preferably 0.5 to 5 parts by weight.

For example, the first photoinitiator may be TPO or I-907, but is not limited thereto.

<Second adhesive composition>

The second adhesive composition according to an embodiment of the present invention includes an acrylic composition or a siloxane composition, a crosslinking agent, and a second photoinitiator. For example, the second photoinitiator may be CP-4 (I-184) or I-819, but is not limited thereto.

In addition, the second photoinitiator is characterized in that the 380 nm absorption coefficient at a concentration of 0.1% is less than 0.8, and the second photoinitiator may be included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the polymer included together.

When the second adhesive composition is composed of a siloxane composition rather than an acrylic composition, the second adhesive composition can be physically peeled off by the tackiness of the siloxane composition. In this case, the second adhesive composition includes a second photoinitiator. may not be included.

acrylic composition

Since the same acrylic composition as the first adhesive composition can be used, overlapping descriptions will be omitted.

Siloxane-based composition

Referring to the siloxane composition (siloxane resin layer) according to an embodiment of the present invention as an example, a resin layer is prepared by mixing polyorganosiloxane, polyorganohydrogensiloxane, a platinum-based catalyst, and an inhibitor. The polyorganosiloxane may be one or more, and the polyorganosiloxane may also be one or more.

The alkenyl group bonded to the silicon atom of the polyorganosiloxane may be selected from the group consisting of a vinyl group, a propynyl group, a butynyl group, a pentynyl group, a hexynyl group, an octynyl group, a decynyl group, a hexadecynyl group, and an octadecinyl group. . Such an alkenyl group may be bonded to a silicon atom present at the end of the molecule rather than a silicon atom present in the side chain of the molecule of the polyorganosiloxane, thereby increasing the curing speed of the adhesive composition.

Polyorganohydrogensiloxane has at least two or more hydrogen atoms (Si-H bonds) bonded to silicon atoms in one molecule, and serves as a crosslinking agent. In the silicon atom present at the terminal or side chain of the molecule of polyorganohydrogensiloxane, the silicon atom to which no hydrogen atom is bonded is a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms (eg, an alkyl group having 1 to 10 carbon atoms). , an aryl group having 6 to 10 carbon atoms) may be bonded.

Specifically, polyorganohydrogensiloxane is a dimethylsiloxane-methylhydrogensiloxane copolymer capped with trimethylsiloxy groups at both ends of the molecule, polydimethylsiloxane capped with dimethylhydrogensiloxy groups at both ends, and dimethylsiloxane at both ends of the molecule. It may be a dimethylsiloxane/methylhydrogensiloxane copolymer capped with hydrogensiloxy groups, or a copolymer of methylhydrogensiloxane and cyclic dimethylsiloxane.

The content of the polyorganohydrogensiloxane may be 2 to 20 parts by weight based on 100 parts by weight of the adhesive composition. When the content of the polyorganohydrogensiloxane is less than 2 parts by weight, the hardness of the cured product may decrease, and when it exceeds 20 parts by weight, the crosslinking density of the cured product may be excessively increased.

The platinum-based catalyst serves to accelerate the curing reaction of the adhesive composition. The platinum-based catalyst may be a platinum-containing complex compound (eg, a platinum-vinylsiloxane complex compound). The content of the platinum-based catalyst may be 0.1 to 0.5 parts by weight based on 100 parts by weight of the adhesive composition. If the content of the platinum-based catalyst is less than 0.1 parts by weight, the curing rate of the adhesive composition may be slowed down, and if it exceeds 0.5 parts by weight, the curing rate may be excessively fast and workability may be deteriorated due to lack of pot life.

ECH (Ethynyl cyclohexanol 50% in toluene) can be used as an inhibitor, and can be expressed as an inhibitor for catalysts. Examples of catalyst inhibitors include ethylenically unsaturated amides, aromatically unsaturated amides, acetylenic compounds, ethylenically unsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbon diesters, unsaturated hydrocarbon mono-esters of unsaturated acids, conjugates Gated n-phosphorus, hydroperoxides, ketones—sulfoxides, amines, phosphines, phosphites, nitrites, and diaziridines.

The siloxane resin layer is prepared by adding 100 parts by weight of polyorganosiloxane, 5 to 20 parts by weight of polyorganosiloxane, 0.1 to 5 parts by weight of a platinum catalyst, and 1/500 to 1/200 parts by weight of an inhibitor based on the weight of polyorganosiloxane. can be produced

cross-linking agent

Since the same crosslinking agent as that of the first adhesive composition can be used, overlapping descriptions will be omitted.

Second photoinitiator

The second adhesive composition includes a second photoinitiator.

The second adhesive composition according to an embodiment of the present invention includes a second photoinitiator having a 380nm extinction coefficient of less than 0.8 at a concentration of 0.1%, and the second photoinitiator is included together in order to prevent the adhesive strength from being lowered in the 380nm LED ultraviolet light. It may be included in 0.4 or more and less than 5 parts by weight, preferably 0.5 to 5 parts by weight, based on the polymer to be.

For example, the second photoinitiator may be CP-4 (I-184) or I-819, but is not limited thereto.

<Method for producing double-sided adhesive sheet>

2a to 2b are diagrams illustrating a method for manufacturing a double-sided pressure-sensitive adhesive sheet according to the present invention. The first adhesive layer 110 according to the present embodiment is formed of the first adhesive composition, and the second adhesive layer 120 is formed of the second adhesive composition.

Preparation of adhesive composition

The first adhesive composition according to this embodiment may be prepared by mixing 2 to 6 parts by weight of a crosslinking agent/curing agent, 0.5 to 2 parts by weight of a first photoinitiator, and 2 to 6 parts by weight of an adhesion control agent M130G with respect to 100 parts by weight of the acrylic composition. .

The second adhesive composition according to this embodiment may be prepared by mixing 2 to 6 parts by weight of a crosslinking agent/curing agent, 0.5 to 2 parts by weight of a second photoinitiator, and 2 to 6 parts by weight of an adhesion control agent M130G with respect to 100 parts by weight of the acrylic composition. .

At this time, HDI, TDI, Aziridine, or Epoxy-type may be used as the crosslinking agent, but is not limited thereto, and CP-4, TPO, I-184, etc. may be used as the photoinitiator, but is not limited thereto.

Additionally, the first and second adhesive compositions may be prepared by further mixing additives, solvents, and the like. In this case, the additive may include an AS additive, an adhesiveness adjusting additive, a dye, a pigment, and the like, and a solvent may be included for viscosity control, but is not limited thereto.

Preparation of the first adhesive layer

In order to manufacture the first adhesive layer 110 according to the present embodiment, the first adhesive composition is prepared so that the thickness of the first adhesive layer 110 after drying is 60 to 120 μm (one embodiment: about 100 μm). It is coated on the release surface of the first release film 140 . The coated first release film 140 is dried, for example, at 100° C. for 5 minutes to volatilize the solvent. At this time, the first release film 140, for example, 38㎛, may be a silicon release treatment film.

When the thickness of the first adhesive layer 110 exceeds 120 μm, internal curing by LED ultraviolet rays of a predetermined wavelength is insufficient due to an increase in adhesive strength, even after the first adhesive layer 110 is separated from the wafer. Remnants of layer 110 may remain on the wafer.

In addition, when the thickness of the first adhesive layer 110 is less than 60 μm, it may not be suitable for wafer processing due to lack of concavo-convex covering performance.

The double-sided adhesive sheet 100 according to the present embodiment may be adhered to the wafer after removing the first release film 140, and after wafer processing, the double-sided adhesive sheet 100 may be peeled from the wafer if necessary.

Preparation of the second adhesive layer

In order to manufacture the second adhesive layer 120 according to this embodiment using an acrylic composition, the thickness of the second adhesive layer 120 after drying is 10 to 50 μm (in one embodiment: about 30 μm) , The second adhesive composition is coated on the release surface of the second release film 150 . The coated second release film 150 is dried, for example, at 100° C. for 5 minutes to volatilize the solvent. At this time, the second release film 150 (one embodiment: 38 μm) may be a silicone release treatment film.

As shown in FIG. 2A, when the middle layer 130 does not exist on the double-sided adhesive sheet 100, the thickness of the second adhesive layer 120 may be 30 to 50 μm, and as shown in FIG. 2B, Likewise, when the middle layer 130 is present in the double-sided adhesive sheet 100, the thickness of the second adhesive layer 120 may be 10 to 50 μm.

When the intermediate layer 130 is present as shown in FIG. 2B, if the final thickness of the double-sided adhesive sheet 100 exceeds 200 μm, problems may occur when inputting the process equipment, and the thickness of the second adhesive layer 120 If it is 10 μm or less, the adhesive strength may be insufficient.

In addition, when the intermediate layer 130 does not exist as shown in FIG. 2A, when the thickness of the second adhesive layer 120 is 30 μm or less, the adhesive strength may be insufficient, and the thickness of the second adhesive layer 120 is 50 μm. In this case, a phenomenon in which the second adhesive layer 120 is pushed during the wafer grinding process may occur.

In addition, when the second adhesive layer 120 is manufactured using a siloxane composition, the siloxane composition is applied to one surface of the intermediate layer 130 made of PI so that the thickness of the second adhesive layer 120 after drying becomes about 30 μm. Do pottery. The coated intermediate layer 130 is dried at 150° C. for 5 minutes to produce an intermediate product composed of a PI/Si adhesive layer. When the siloxane composition is used for the second adhesive layer 120, it is preferable that the middle layer 130 is present on the double-sided adhesive sheet 100 in order to satisfy the drying condition of 150°C.

The double-sided adhesive sheet 100 according to the present embodiment may be adhered to the carrier glass after removing the second release film 150, and after wafer processing, the double-sided adhesive sheet 100 may be peeled from the carrier glass as necessary. there is.

Manufacture of the middle layer

The double-sided adhesive sheet 100 according to the present invention may or may not include the first adhesive layer 110, the second adhesive layer 120, and the intermediate layer 130, and in the case of including the intermediate layer 130, the above The intermediate layer 130 may be positioned between the first adhesive layer 110 and the second adhesive layer 120 .

In order to manufacture the intermediate layer 130 according to the present embodiment, a 40 μm transparent PI film that transmits ultraviolet rays is prepared. By corona-treating both sides of the PI film, adhesion to the adhesive composition can be increased.

The intermediate layer 130 may be implemented using a PI film, but is not limited thereto, and various films having heat resistance and UV transmittance, such as silicone and epoxy compositions, may be applied.

Production of double-sided adhesive sheet

As shown in FIG. 2B, when the intermediate layer 130 exists, the second adhesive layer 120 is roll-laminated on one surface of the intermediate layer 130 to bond the second adhesive layer 120 to the intermediate layer 130, The first adhesive layer 110 is roll-laminated on the surface opposite to the surface on which the second adhesive layer 120 is formed, and the first adhesive layer 110 is bonded to the intermediate layer 130 . Accordingly, the double-sided adhesive sheet 130 in which the first adhesive layer 110 and the second adhesive layer 120 are laminated on both sides of the middle layer 130 may be manufactured.

As shown in FIG. 2A , when the intermediate layer 130 does not exist, the first adhesive layer 110 is laminated on the second adhesive layer 120 to form the first adhesive layer 110 and the second adhesive layer 120. This laminated double-sided adhesive sheet 100 can be manufactured.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples. The following examples may be appropriately modified or changed by those skilled in the art within the scope of the present invention.

According to the method described above, the double-sided adhesive sheet 100 of Examples and Comparative Examples was produced.

Preparation Example 1: Preparation of acrylic composition

110 parts by weight of 2-ethylhexyl acrylate (2-EHAM) and 90 parts by weight of butyl acrylate (BAM) in a 1L reactor equipped with a cooling device so that nitrogen gas is refluxed and the temperature is easily controlled A monomer mixture consisting of 15 parts by weight of 2,3-epoxypropyl methacrylate (GMA) and 15 parts by weight of acrylic acid (AAc) was mixed with 150 parts by weight of ethyl acetate (EAC). After putting it in, nitrogen gas was purged for 1 hour to remove oxygen, and then maintained at 80°C. After uniformly mixing the monomer mixture, 2,2'-azobis (isobutyronitrile) (2,2'-azobis (isobutyronitrile), AIBN) 0.8 parts by weight and benzoyl peroxide (benzoyl peroxide, BPO) 0.8 Part by weight was added. After stirring, an acrylic polymer was prepared by irradiation with a UV lamp (10 mW).

The prepared acrylic polymer was mixed with ethyl acetate (EAC) to adjust the solid content to 35%, and the viscosity was 2,500 cps (25 ° C)

Preparation Example 2: Preparation of siloxane composition

Based on 100 parts by weight of a siloxane polymer having a polyvinyl functional group (VPR0600N, Biogen Korea), 18 parts by weight of siloxane-H polymer (XL-02, Biogen Korea) was added as a crosslinking agent, and ECH (1-Ethynylcyclohexanol, Merck Co., Ltd.) was added as an inhibitor. ) 0.4 parts by weight, and additionally, 1 part by weight of platinum catalyst CPT-037 (Platinum Catalyst, Biogen Korea) was mixed to prepare a siloxane composition. 30 parts by weight of toluene as a solvent is added to the composition to improve coating performance.

Preparation Example 3: Production of Siloxane Adhesive Sheet

When the intermediate layer is present, the siloxane composition of Preparation Example 2 prepared as described above is coated on one surface of the second intermediate layer according to the thickness after drying. The coated laminated film was dried at 150° C. for 5 minutes to volatilize the solvent and heat-cured, and roll-laminated 38PET treated with silicon on the surface of the siloxane sheet to prepare a siloxane adhesive sheet.

Example 1

In manufacturing the double-sided adhesive sheet 100, the first adhesive composition includes the acrylic composition of Preparation Example 1, the crosslinking agent, and the first photoinitiator (A) in the following weight ratio as polymers, and the thickness of the first adhesive layer is It was made to be 100 μm.

Acrylic composition: crosslinking agent: first photoinitiator (A) = 100: 6: 1

The second adhesive composition may include the acrylic composition of Preparation Example 1, the crosslinking agent, and the second photoinitiator (B) as polymers in the following proportions, and may be prepared such that the thickness of the second adhesive layer is 30 μm.

Acrylic composition: crosslinking agent: second photoinitiator (B) = 100: 6: 1

The middle layer was made of PI and had a thickness of 55 μm.

Example 2

In manufacturing the double-sided adhesive sheet 100, the adhesive sheet was manufactured in the same manner as in Example 1, except that the thickness of the second adhesive layer was 50 μm and the intermediate layer was not included.

Example 3

In manufacturing the double-sided adhesive sheet 100, the ratio of the first photoinitiator (A) in the first adhesive composition is reduced to 0.5, and the ratio of the second photoinitiator (D) in the second adhesive composition is reduced to 0.5. Except for the above, a pressure-sensitive adhesive sheet was prepared in the same manner as in Example 2.

Example 4

In preparing the double-sided adhesive sheet 100, the first adhesive composition includes the acrylic composition of Preparation Example 1, the crosslinking agent, and the first photoinitiator (A) in the following weight ratios, and the thickness of the first adhesive layer is 100 μm It can be manufactured to become

Acrylic composition: crosslinking agent: first photoinitiator (A) = 100: 6: 0.5

The second adhesive composition may include the siloxane composition of Preparation Example 2, the crosslinking agent, and the second photoinitiator (B) in the following proportions, and the second adhesive layer may have a thickness of 30 μm.

Siloxane composition: crosslinking agent: second photoinitiator (B) = 100: 2: 1

The intermediate layer is composed of PI and can be manufactured to have a thickness of 55 μm.

Example 5

In preparing the double-sided adhesive sheet 100, the first adhesive composition includes the acrylic composition of Preparation Example 1, the crosslinking agent, the first photoinitiator (A), and the first photoinitiator (C) in the following proportions, 1 It can be manufactured so that the thickness of an adhesive layer may become 100 micrometers.

Acrylic composition: crosslinking agent: first photoinitiator (A): first photoinitiator (C) = 100: 6: 0.5: 0.5

The second adhesive composition may include an acrylic composition, a crosslinking agent, a second photoinitiator (B), and a second photoinitiator (D) in the following weight ratios, and may be manufactured such that the thickness of the second adhesive layer is 30 μm.

Acrylic composition: Crosslinking agent: Second photoinitiator (B): Second photoinitiator (D) = 100: 6: 0.5: 0.5

The intermediate layer is composed of PI and can be manufactured to have a thickness of 30 μm.

Example 6

In manufacturing the double-sided adhesive sheet 100, the first photoinitiator (C) is used in the same ratio instead of the first photoinitiator (A) in the first adhesive composition, and the second photoinitiator (B) is used in the second adhesive composition. A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that the second photoinitiator (D) was used in the same ratio.

Comparative Example 1

In manufacturing the double-sided adhesive sheet 100, the same method as in Example 1 was used except that the second photoinitiator (B) was used in the same ratio instead of the first photoinitiator (A) in the first adhesive composition. An adhesive sheet was prepared.

Comparative Example 2

In preparing the double-sided adhesive sheet 100, the adhesive sheet was prepared in the same manner as in Example 1, except that the ratio of the first photoinitiator (A) in the first adhesive composition was reduced to 0.4. The first adhesive composition of Comparative Example 2 may include the acrylic composition of Preparation Example 1, the crosslinking agent, and the first photoinitiator (A) in the following weight ratio.

Acrylic composition: crosslinking agent: first photoinitiator (A) = 100: 6: 0.4

Comparative Example 3

In preparing the double-sided adhesive sheet 100, the siloxane composition of Preparation Example 2 was used in the same ratio instead of the acrylic composition in the first adhesive composition, and the ratio of the crosslinking agent was reduced to 2, the same as in Comparative Example 1. An adhesive sheet was prepared using the method.

Comparative Example 4

In manufacturing the double-sided adhesive sheet 100, the adhesive sheet was manufactured in the same manner as in Example 2, except that the thickness of the first adhesive layer was increased to 130 μm.

Comparative Example 5

In manufacturing the double-sided adhesive sheet 100, the adhesive sheet was manufactured in the same manner as in Example 1, except that the thickness of the first adhesive layer was reduced to 50 μm.

The composition and contents of the adhesive compositions according to Examples 1 to 6 and Comparative Examples 1 to 5 are shown in Table 1 below. Units are parts by weight.

adhesive layer
Kinds polymer
(acryl
composition) polymer
(siloxane
composition) cross-linking agent light 1
initiator
(A) 2nd light
initiator
(B) light 1
initiator
(C) 2nd light
initiator
(D) coating
thickness
(μm) middle layer
thickness
(μm) Example 1 No. 1 100 - 6 One 0 - - 100 55 2nd 100 - 6 0 One - - 30 Example 2 No. 1 100 - 6 One 0 - - 100 - 2nd 100 - 6 0 One - - 50 Example 3 No. 1 100 - 6 0.5 0 - - 100 - 2nd 100 - 6 0 0.5 - - 50 Example 4 No. 1 100 - 6 0.5 0 - - 100 55 2nd - 100 2 0 One - - 30 Example 5 No. 1 100 - 6 0.5 0 0.5 0 100 55 2nd 100 - 6 0 0.5 0 0.5 30 Example 6 No. 1 100 - 6 - - One 0 100 55 2nd 100 - 6 - - 0 One 30 Comparative Example 1 No. 1 100 - 6 0 One - - 100 55 2nd 100 - 6 0 One - - 30 Comparative Example 2 No. 1 100 - 6 0.4 0 - - 100 55 2nd 100 - 6 0 One - - 30 Comparative Example 3 No. 1 - 100 2 0 One - - 100 55 2nd 100 - 6 0 One - - 30 Comparative Example 4 No. 1 100 - 6 One 0 - - 130 - 2nd 100 - 6 0 One - - 50 Comparative Example 5 No. 1 100 - 6 One 0 - - 50 55 2nd 100 - 6 0 One - - 30

In Table 1, the acrylic composition means an acrylic resin as a polymer, the siloxane composition is a siloxane resin as a polymer, the first photoinitiator (A) is TPO, and the second photoinitiator (B) is CP-4 (I-184) , The first photoinitiator (C) was I-907 and the second photoinitiator (D) was I-819, and PI was used as the intermediate layer.

<Experimental example>

For the adhesive layers formed by the adhesive compositions according to Examples and Comparative Examples, peel force and uneven cover performance were evaluated, and the results are shown in Table 2 below. The measurement method and evaluation method used in the present invention are as follows.

1. Measurement of peel force

After the adhesive sheet was adhered to the mirror wafer or Corning glass, 500 mJ of high-pressure mercury ultraviolet light and 250 mJ of 380 nm LED ultraviolet light were irradiated, respectively, to measure the peel force according to each light source.

The peel force was measured by cutting the adhesive sheet containing the adhesive composition according to Examples 1 to 6 and Comparative Examples 1 to 5 into a width of 25 mm and a length of 150 mm, preparing a sample, and then peeling at 180 ° using a universal tester (Shimadzu). Adhesion was evaluated. More specifically, after the adhesive layer of the prepared adhesive sheet sample was adhered and fixed to the mirror wafer and Corning glass, one side was fixed to the clamp on the load cell side of the universal testing machine, and the adhesive sheet was peeled off at a speed of 300 mm/min. Adhesion was measured. The values listed in Table 2 are average values for a total of three measurements, and the unit is N/25 mm.

2. Measurement of uneven cover performance

Convex-convex cover performance was measured using a wafer with bumps having a height of 50 μm. The adhesive sheet containing the adhesive composition according to Examples 1 to 6 and Comparative Examples 1 to 5 was liraminated on the wafer, and the first adhesive surface of the adhesive sheet was attached while heating at 90 ° C. After attachment, a static pressure thickness meter (Techlock Co., PG-02) Measure the total thickness Wa (distance from the back side of the wafer to the surface of the second adhesive surface of the adhesive sheet) and the total thickness Wb of the portion without bumps, Wa -Wb was calculated as a height difference. The smaller the difference in height, the more unevenness caused by the height of the bump is embedded in the adhesive sheet and alleviated. Accordingly, when the height difference (Wa-Wb) was less than 10 μm, the uneven cover performance was evaluated as “Yes”, and when the height difference was greater than 10 μm, the uneven cover performance was evaluated as “No”.

3. Measurement of extinction coefficient

0.1 wt% of the photoinitiator to be measured is dissolved in an acetone solvent. The extinction coefficient is measured using SHIMADZU's UV-2600 UV-VIS Spectrophotometer. A baseline was measured with acetone, and a 0.1 wt% solution was set to measure an area of 300 to 500 nm, and the data of 330 to 450 nm were confirmed and shown in FIG. 3 . Referring to FIG. 3 , the second photoinitiator, CP-4, has an extinction coefficient of less than 0.8 at 380 nm to 380 nm, and the first photoinitiator, TPO, has an extinction coefficient of 0.8 or more at 380 nm to 380 nm.

adhesive layer
Kinds Adhesion (Mirror Wafer) Adhesion (Glass) Convex and convex cover performance LED UV High Pressure Mercury UV LED UV High Pressure Mercury UV Example 1 No. 1 0.18 0.18 0.25 0.27 Yes 2nd 1.30 0.05 1.4 0.1 Example 2 No. 1 0.20 0.20 0.25 0.28 Yes 2nd 1.32 0.05 1.4 0.1 Example 3 No. 1 0.25 0.20 0.28 0.21 Yes 2nd 1.30 0.08 1.4 0.085 Example 4 No. 1 0.25 0.20 0.27 0.23 Yes 2nd 0.70 0.40 0.8 0.06 Example 5 No. 1 0.19 0.18 0.26 0.27 Yes 2nd 1.31 0.05 1.4 0.05 Example 6 No. 1 0.19 0.19 0.25 0.25 Yes 2nd 1.33 0.05 1.42 0.05 Comparative Example 1 No. 1 1.50 0.07 1.6 0.1 Yes 2nd 1.30 0.05 1.4 0.08 Comparative Example 2 No. 1 0.55 0.67 0.61 0.69 Yes 2nd 1.30 0.05 1.4 0.1 Comparative Example 3 No. 1 0.70 0.50 0.88 0.6 No 2nd 1.30 0.05 1.4 0.1 Comparative Example 4 No. 1 0.45 0.44 0.5 0.6 Yes 2nd 1.35 0.08 1.46 0.2 Comparative Example 5 No. 1 0.20 0.20 0.25 0.25 No 2nd 1.30 0.05 1.4 0.1

After the first adhesive layer is irradiated with 380 nm LED ultraviolet rays (first process), the adhesive strength must be 0.25 N/25 mm or less so that the adhesive sheet can be peeled off without damaging the wafer. If the adhesive strength of the first adhesive layer is maintained beyond 0.25 N/25 mm even after irradiation with 380 nm LED ultraviolet light, problems such as wafer cracks or adhesive transfer may occur.

The adhesive strength of the second adhesive layer should be 0.1 N/25 mm or less after being irradiated with high-pressure mercury ultraviolet rays (secondary process) so that the adhesive sheet can be peeled off without damaging the carrier glass.

In the case of using the siloxane composition for the second adhesive layer, the siloxane composition has very strong adhesion against lateral vibration, but can be easily peeled off at 90 ° or 180 ° peeling, so it can be used for the second adhesive layer. For example, if the siloxane composition has an adhesive force of 0.7 N/25 mm or less, it can be applied to a secondary process of irradiating high-pressure mercury ultraviolet rays.

In the case of the siloxane composition, performance such as vibration resistance is advantageous, but the performance of absorbing wafer bumps is comparable, so it cannot be applied to the first adhesive layer.

The results of peeling the adhesive sheet according to the adhesive sheet and the peeling method of the adhesive sheet according to the present invention will be described with reference to Table 2 above.

After irradiation with 380 nm LED ultraviolet light, the adhesive force of the first adhesive layer adhered to the mirror wafer in Examples 1 to 6 was measured to be 0.25 N/25 mm or less, and it was evaluated that the uneven cover was also possible. In addition, even when irradiated with 380 nm LED ultraviolet light, the adhesive strength of the second adhesive layer adhered to the glass was maintained at 0.8 to 1.42 N/25 mm.

In addition, after irradiation with high-pressure mercury ultraviolet rays, the adhesive force of the second adhesive layer adhered to the glass in Examples 1 to 6 was measured to be 0.1 N/25 mm or less.

On the other hand, in the case of Comparative Example 1 including the second photoinitiator instead of the first photoinitiator in the first adhesive layer, the adhesive force of the first adhesive layer to the mirror wafer was measured as 1.5 N/25mm after irradiating with 380 nm LED ultraviolet light. , it can be confirmed that it is difficult to smoothly peel the adhesive sheet from the wafer.

In the case of Comparative Example 2 including 0.38 wt% of the first photoinitiator, which is out of 0.5 to 5 wt% based on the total weight of the first adhesive composition, the adhesive strength of the first adhesive layer to the mirror wafer after irradiation with 380 nm LED ultraviolet light was 0.55% by weight. As measured by N/25 mm, it can be confirmed that it is difficult to smoothly peel the adhesive sheet from the wafer.

In the case of Comparative Example 3 in which the siloxane composition was included in the first adhesive composition instead of the acrylic composition, it could be confirmed that the uneven cover was not formed.

In the case of Comparative Example 4, in which the thickness of the first adhesive layer was 130 μm and the thickness of the second adhesive layer was 50 μm, and there was no intermediate layer, the adhesive strength of the first adhesive layer to the mirror wafer was 0.45 N/25 mm after irradiation with 380 nm LED ultraviolet light. As measured by , it can be confirmed that it is difficult to smoothly peel the adhesive sheet from the wafer.

In the case of Comparative Example 5 in which the thickness of the first adhesive layer is 50 μm and the thickness of the second adhesive layer is 30 μm, it can be confirmed that the uneven cover is not formed.

Double-sided adhesive sheet (100)
Wafer(200)
Carrier Glass (300)
First light source 400
Second light source 500
First adhesive layer 110
Second adhesive layer 120
Intermediate layer (130)
The first release film (140)
Second release film (150)

Claims (13)

a first adhesive layer formed of a first adhesive composition and located on the first side of the double-sided adhesive sheet; and
A second adhesive layer formed of a second adhesive composition and located on a second surface that is a back surface of the first surface;
The first adhesive composition includes a polymer and a first photoinitiator,
The first photoinitiator has an absorption coefficient of 0.8 or more at 380 nm at a concentration of 0.1%, and is included in 0.5 to 5 parts by weight based on 100 parts by weight of the polymer.
According to claim 1,
The second adhesive composition includes a polymer and a second photoinitiator,
The second photoinitiator has an extinction coefficient of less than 0.8 at 380 nm at a concentration of 0.1%, and is included in 0.5 to 5 parts by weight based on 100 parts by weight of the polymer.
According to claim 1,
The thickness of the first adhesive layer is characterized in that 20 to 130 ㎛,
The double-sided adhesive sheet, characterized in that the thickness of the second adhesive layer is 10 to 50 ㎛.
According to claim 1,
The double-sided adhesive sheet further comprising an intermediate layer between the first adhesive layer and the second adhesive layer.
According to claim 4,
The double-sided pressure-sensitive adhesive sheet, characterized in that the middle layer comprises polyimide.
According to claim 1,
The first adhesive layer is adhered to the wafer during wafer processing,
The double-sided adhesive sheet is characterized in that the double-sided adhesive sheet is peeled from the wafer by LED ultraviolet rays of a predetermined wavelength irradiated to the double-sided adhesive sheet.
According to claim 6,
The second adhesive layer is adhered to a carrier glass for wafer processing during wafer processing,
After the double-sided adhesive sheet is separated from the wafer, the double-sided adhesive sheet is peeled from the carrier glass by high-pressure mercury ultraviolet rays irradiated to the double-sided adhesive sheet.
According to claim 1,
Double-sided adhesive sheet for semiconductor wafer processing.
According to claim 1,
A double-sided adhesive sheet, characterized in that the adhesive strength of the first adhesive composition is smaller than the adhesive strength of the second adhesive composition.
In the method of peeling the double-sided adhesive sheet adhered to the wafer and the carrier glass,
irradiating 380nm LED ultraviolet light to lower the adhesive strength of the first adhesive layer of the double-sided adhesive sheet to peel the double-sided adhesive sheet from the wafer; and
In order to peel the second adhesive layer of the double-sided adhesive sheet from the carrier glass, irradiating high-pressure mercury ultraviolet rays to lower the adhesive strength of the second adhesive layer of the double-sided adhesive sheet; Including,
The first adhesive layer includes a first photoinitiator having an extinction coefficient of 0.8 or more at 380 nm at a concentration of 0.1%,
The second adhesive layer includes a second photoinitiator having an extinction coefficient of 380 nm of less than 0.8 at a concentration of 0.1%.
According to claim 10,
The first adhesive layer is formed from a first adhesive composition, the first adhesive composition includes a polymer and a first photoinitiator,
The first photoinitiator is included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the polymer;
The second adhesive layer is formed from a second adhesive composition, the second adhesive composition includes a polymer and a second photoinitiator,
The second photoinitiator is a double-sided adhesive sheet peeling method, characterized in that included in 0.5 to 5 parts by weight relative to 100 parts by weight of the polymer.
According to claim 10,
The double-sided adhesive sheet peeling method characterized in that it further comprises an intermediate layer between the first adhesive layer and the second adhesive layer.
According to claim 12,
The double-sided adhesive sheet peeling method, characterized in that the middle layer comprises polyimide.

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