Adhesive tape

Abstract

The purpose of this invention is to provide an adhesive tape that effectively adheres to wafer components when receiving them and exhibits excellent peeling performance during re-transfer of wafer components, suppressing adhesive residue on the wafer components. This invention is an adhesive tape having an adhesive layer with a ball tack of No. 12 or less, and the ratio of the thickness t (μm) of the adhesive layer to the shear storage modulus G' (kPa) of the adhesive layer at 23°C and 1Hz, t / G', is 1 or more.

Description

Technical Field

[0001] This invention relates to an adhesive tape. Prior Technology

[0002] In the manufacturing process of semiconductor devices, multiple wafer components disposed on an adhesive layer are sometimes transferred onto a drive circuit substrate. For example, a micro-LED display is a display device in which each pixel is a tiny light-emitting diode (LED) chip that emits light to display images. Micro-LED displays are attracting attention as a next-generation display device due to their high contrast, fast response time, and ability to be thinner because they do not require the color filters used in LCDs and OLEDs. In a micro-LED display, multiple micro-LED chips are densely packed into a planar shape.

[0003] In the manufacturing process of semiconductor devices such as micro LED displays, for example, a transfer laminate on which multiple chip components are disposed on an adhesive layer is aligned with a driving circuit substrate, and the chip components are peeled off from the transfer laminate and electrically connected to the driving circuit substrate (transfer step).

[0004] The transfer process may sometimes be performed multiple times. That is, the following operation is performed: before finally transferring the wafer component onto the drive circuit board, the wafer component is temporarily transferred onto a carrier material for transport or processing, and then the wafer component is transferred from the carrier material to another carrier material or drive circuit board. As a carrier material, for example, Patent Document 1 describes a transfer substrate having at least a substrate and an impact-absorbing layer. [Previous Technical Documents] [Patent Literature]

[0005] [Patent Document 1] International Publication No. 2019 / 065441 Summary of the Invention

[0006] As a carrier material, since it is also necessary to temporarily maintain the performance of the chip components, the use of adhesive tape with an adhesive layer is also being studied. However, when using conventional adhesive tape as a carrier material, sometimes the chip component does not adhere to the tape when receiving it, making proper transfer impossible. Furthermore, when transferring the chip component to other carrier materials or driver circuit boards after receiving it, the following problems also occur: poor chip component peeling, or even if the chip component can be peeled off, adhesive residue remains on the chip component.

[0007] The purpose of this invention is to provide an adhesive tape that can effectively adhere to wafer components when they are being received, and can also exhibit excellent peeling performance when wafer components are being re-transferred, thereby suppressing adhesive residue on the wafer components.

[0008] The present invention 1 is an adhesive tape having an adhesive layer having a ball tack of No. 12 or less, and the ratio of the thickness t (μm) of the adhesive layer to the shear storage modulus G' (kPa) of the adhesive layer at 23°C and 1Hz being t / G' or more. The present invention 2 is an adhesive tape as in the present invention 1, which satisfies the following formula (1) when the ball adhesion No of the adhesive layer is y. y≧-13.366(t / G')+28.94 (1) The present invention 3 is an adhesive tape as in the present invention 2, which satisfies the following formula (2) when the spherical tack No of the adhesive layer is y. y≧-11.981(t / G')+41.528 (2) The present invention 4 is an adhesive tape as in the present invention 1, wherein the spherical tack of the adhesive layer is No. 4 or below. This invention 5 is an adhesive tape as described in inventions 1, 2, 3, or 4, wherein the adhesive layer contains a (meth)acrylic polymer, the (meth)acrylic polymer containing 40% by weight or more of (meth)acrylic ester constituent units that have a glass transition temperature (Tg) below 0°C when formed as a homopolymer. Furthermore, in this specification, "(meth)acrylic acid" means "methacrylic acid and / or acrylic acid". The present invention 6 is an adhesive tape as described in the present invention 5, wherein the (meth)acrylate having a glass transition temperature (Tg) below 0°C when formed as a homopolymer contains: (meth)acrylate having an alkyl group having 12 or more carbon atoms and having a glass transition temperature (Tg) below 0°C when formed as a homopolymer. The present invention 7 is an adhesive tape as described in the present invention 5 or 6, wherein the weight average molecular weight of the (meth)acrylic polymer is less than 1 million. The present invention 8 is an adhesive tape as described in the present invention 6, wherein the (meth)acrylate having an alkyl group having 12 or more carbon atoms and having a glass transition temperature (Tg) below 0°C when formed as a homopolymer contains lauryl methacrylate. The present invention 9 is an adhesive tape as described in the present invention 5 or 6, wherein the (meth)acrylate having a glass transition temperature (Tg) below 0°C when formed as a homopolymer contains: an (meth)acrylate having an alkyl group having 7 or more but less than 12 carbon atoms and having a glass transition temperature (Tg) below 0°C when formed as a homopolymer. The present invention 10 is an adhesive tape as described in invention 5, 6, 7, 8 or 9, wherein the (meth)acrylic polymer contains 3% by weight or more of constituent units derived from monomers containing hydroxyl groups. The present invention 11 is an adhesive tape as described in invention 5, 6, 7, 8, 9 or 10, wherein the adhesive layer further contains an isocyanate-based crosslinking agent. The present invention 12 is an adhesive tape as described in present invention 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the gel content of the adhesive layer is 80% by weight or more and 95% by weight or less. The present invention 13 is an adhesive tape as described in present invention 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, having a substrate. The present invention 14 is an adhesive tape as described in present invention 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13, which is used in the step of transferring parts to support the parts. The present invention 15 is an adhesive tape as described in the present invention 14, wherein the component is a semiconductor device. The present invention will be described in detail below.

[0009] The inventors have discovered that by adjusting the spherical tack of the adhesive layer to a specific range and adjusting the ratio t / G' of the adhesive layer thickness t (μm) to the shear storage modulus G' (kPa) of the adhesive layer at 23°C and 1Hz to a specific range, an adhesive tape suitable as a carrier material can be obtained. That is, the inventors have discovered that with this type of adhesive tape, when receiving wafer components, it can adhere well to the wafer components, and when re-transferring wafer components, it can exhibit excellent peeling performance, suppressing adhesive residue on the wafer components, thus completing the present invention.

[0010] Figure 1 shows a cross-sectional view schematically illustrating an example of the step of transferring a wafer component disposed on an adhesive layer onto an adhesive tape. In the steps shown in Figure 1, a wafer component 1 is disposed on an adhesive layer 4 laminated on a substrate 5. The wafer component 1 is peeled off from the adhesive layer 4, for example, by means of laser irradiation. An adhesive tape 8 is used to receive the wafer component 1 peeled off from the adhesive layer 4, and then the wafer component 1 is transferred to another carrier material or a carrier material on a driving circuit board. The adhesive tape 8 has at least an adhesive layer 2, and may also have a substrate 3 if necessary. Additionally, regarding the laminate 9 of substrate 5 and adhesive layer 4, for example, it can be a single-sided adhesive tape in which "substrate 5 is a substrate such as a resin film, and adhesive layer 4 is composed only of adhesive layer", or it can be a laminate of support and double-sided adhesive tape in which "substrate 5 is a support such as a glass substrate, and adhesive layer 4 is a double-sided adhesive tape (which may also have a substrate)".

[0011] The adhesive tape of the present invention is an adhesive tape having an adhesive layer. Regarding the adhesive tape of the present invention, the spherical tack of the adhesive layer is No. 12 or lower. If the spherical tack of the adhesive layer is No. 12 or lower, the adhesive force of the adhesive tape will not be too high, thus exhibiting excellent peel performance during re-transfer of wafer components and suppressing adhesive residue on the wafer components. Preferably, the spherical tack of the adhesive layer is No. 8 or lower, more preferably No. 4 or lower. If the spherical tack of the adhesive layer is No. 4 or lower, the peel performance during re-transfer of wafer components will be particularly high. There is no particular limitation on the lower limit of the spherical tack of the adhesive layer, but from the viewpoint of further improving the retention performance of the wafer components, it is preferably No. 2 or higher, more preferably No. 3 or higher. In addition, the ball tack of the adhesive layer can be measured and calculated, for example, using a ball tack tester (manufactured by Yasuda Seiki Co., Ltd.) in accordance with JIS Z0237, at an environment of 23°C and 50% relative humidity.

[0012] The ratio t (unit: μm) of the adhesive layer thickness t of the adhesive tape of the present invention to the shear storage modulus G' (unit: kPa) of the adhesive layer at 23°C and 1Hz is 1 or more. To ensure proper adhesion of the wafer component to the adhesive tape during wafer component reception, the cushioning properties of the adhesive layer were considered for adjustment. Properties related to the cushioning properties of the adhesive layer include, for example, thickness t and shear storage modulus G'. The inventors have found that adjusting the ratio t / G' is more important than adjusting the individual values ​​of thickness t and shear storage modulus G'. For example, when thickness t is relatively small, shear storage modulus G' must be relatively small, but when thickness t is relatively large, the wafer component can adhere well to the adhesive tape even with a relatively large shear storage modulus G'. In other words, the inventors have found that by adjusting the shear storage modulus G' value based on thickness t, the wafer component can adhere well to the adhesive tape during wafer component reception.

[0013] If the aforementioned t / G' is 1 or higher, the adhesive tape can effectively adhere to the wafer component when receiving it. Preferably, t / G' is 1.3 or higher, and more preferably 2 or higher. There is no particular upper limit to the aforementioned t / G', but from the viewpoint of easily maintaining the shape of the adhesive layer and suppressing the adhesive layer from seeping out from the end of the adhesive tape, a preferred upper limit is 10, and more preferably 5.

[0014] The thickness t (μm) of the adhesive layer is not particularly limited if the t / G' meets the above range, but the preferred lower limit is 30 μm and the preferred upper limit is 200 μm. If the thickness t is within the above range, the adhesive tape can adhere to the wafer component more effectively when receiving it. The preferred lower limit of the thickness t is 40 μm, the preferred upper limit is 150 μm, the even more preferred lower limit is 70 μm, and the even more preferred upper limit is 100 μm.

[0015] The shear storage modulus G' (kPa) of the adhesive layer at 23°C and 1Hz is not particularly limited if the t / G' meets the above range, but the preferred lower limit is 10 kPa and the preferred upper limit is 100 kPa. If the shear storage modulus G' is within the above range, the adhesive tape can adhere to the wafer component more effectively when receiving it. The preferred lower limit of the shear storage modulus G' is 15 kPa and the preferred upper limit is 40 kPa. Additionally, the shear storage modulus G' of the adhesive layer at 23°C and 1Hz can be obtained, for example, by measuring the dynamic viscoelastic spectrum from -40 to 140°C using a viscoelastic spectrometer (IT KEISOKU SEIGYO, DVA-200) at a heating rate of 5°C / min and 1Hz in a simple heating mode, in the form of the storage modulus at 23°C. Furthermore, when the thickness of the aforementioned adhesive layer is less than 100 μm, the adhesive layer for testing is formed by overlapping the aforementioned adhesive layer to achieve a thickness of 100 μm or more. The shear storage modulus G' of the obtained adhesive layer for testing is then measured as described above.

[0016] The adhesive tape of the present invention preferably satisfies the following formula (1) when the spherical tack No of the above-mentioned adhesive layer is set as y. Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≧-13.366(t / G')+28.94 (1)

[0017] The inventors plotted the adhesive tapes obtained in the embodiments and comparative examples described in this specification, setting the vertical axis as "y, which is the spherical tackiness No of the adhesive layer" and the horizontal axis as "t / G'". They then analyzed the relationship between "spherical tackiness No, a property related to the adhesive layer's adhesion" and "t / G', a property related to the adhesive layer's cushioning properties," and the impact of this relationship on the performance of the adhesive tapes (evaluation results of the adhesive tapes obtained in the embodiments and comparative examples). Equation (1) above is based on an approximate straight line [y=-13.366(t / G')+28.94] drawn from specific points among the plotted points. By having y and t / G' that satisfy Equation (1) above, the adhesive tape can adhere to the wafer component more effectively when receiving it. This is believed to be because the adhesive strength and cushioning properties of the adhesive layer have a good relationship. Furthermore, the specific points used to derive the above equation (1) are (t,G',y)=(75,52.9,10) and (t,G',y)=(50,31.9,8).

[0018] The adhesive tape of the present invention, when the spherical tack No of the above-mentioned adhesive layer is set as y, preferably satisfies the following formula (1)'. Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≦-13.366(t / G')+60.187 (1)'

[0019] By having y and t / G' that satisfy the above equation (1)', the adhesive tape can better adhere to the chip components when receiving them. The above equation (1)' is based on the embodiment where y+11.981(t / G') is the largest, which is used to derive the specific point of the above equation (1)' as (t,G',y)=(75,18.5,6).

[0020] When the spherical tack No of the adhesive layer is set as y, the adhesive tape of the present invention preferably satisfies the following formula (2). Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≧-11.981(t / G')+41.528 (2)

[0021] Equation (2) above is based on an approximate straight line [y=-11.981(t / G')+41.528] formed by other specific points among the drawn points. By having y and t / G' that satisfy Equation (2) above, the adhesive tape can better adhere to the wafer component when receiving it. This is thought to be because the relationship between the adhesive force and the cushioning of the adhesive layer is better. In addition, the specific points used to derive Equation (2) above are (t,G',y)=(75,28.5,10) and (t,G',y)=(75,26.8,8).

[0022] When the spherical tack No of the adhesive layer is set as y, the adhesive tape of the present invention preferably satisfies the following formula (2)'. Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≦-11.981(t / G')+54.572 (2)'

[0023] By having y and t / G' that satisfy the above equation (2)', the adhesive tape can better adhere to the chip components when receiving them. The above equation (2)' is based on the embodiment where y+11.981(t / G') is the largest, which is used to derive the specific point of the above equation (2)' as (t,G',y)=(75,18.5,6).

[0024] When the spherical tack No of the adhesive layer described above is set as y, the adhesive tape of the present invention preferably satisfies the following formula (3). Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≧5.411(t / G')-15.939 (3)

[0025] Equation (3) above is based on an approximate straight line [y=5.412(t / G')-15.939] drawn from other specific points among the plotted points. By having y and t / G' that satisfy equation (3) above, the adhesive tape can better adhere to the wafer components when receiving them. This is believed to be because the relationship between the adhesive force and the cushioning of the adhesive layer is better. In addition, the specific points used to derive equation (3) above are (t,G',y)=(75,18.5,6) and (t,G',y)=(180,54.3,2).

[0026] When the spherical tack No of the adhesive layer is set as y, the adhesive tape of the present invention preferably satisfies the following formula (4). Here, t represents the thickness of the adhesive layer (μm), and G' represents the shear storage modulus (kPa) of the adhesive layer at 23°C and 1Hz. y≦5.700(t / G')-5.000 (4)

[0027] Equation (4) above is based on an approximate straight line [y=5.700(t / G')-5.000] drawn from other specific points among the plotted points. By having y and t / G' that satisfy Equation (4) above, the adhesive tape can better adhere to the wafer components when receiving them. This is believed to be because the relationship between the adhesive force and the cushioning of the adhesive layer is better. In addition, the specific points used to derive Equation (4) above are (t,G',y)=(75,28.5,10) and (t,G',y)=(80,28.5,11).

[0028] Figure 2 shows the adhesive tape obtained from the embodiments and comparative examples in this specification, with the vertical axis set to "y of the spherical adhesion No of the adhesive layer" and the horizontal axis set to "t / G'" to plot the points. In Figure 2, the points represented by □ (white square), ● (black circle), and 〇 (white circle) are all adhesive bands where the spherical tack of the adhesive layer obtained in the embodiment is below No. 12 and t / G' is above 1. Among them, the points represented by □ (white square) are adhesive bands where the above formula (1) is not satisfied. The points represented by ● (black circle) are adhesive bands where the above formula (1) is satisfied, and the wafer components can be adhered to better. The points represented by 〇 (white circle) are adhesive bands where both the above formula (1) and the above formula (2) are satisfied, and the wafer components can be adhered to better. On the other hand, the points represented by × are adhesive bands obtained in the comparative example. Furthermore, the approximate straight line in Figure 2 represents the horizontal axis t / G' as x.

[0029] There are no particular limitations on the method for adjusting the spherical viscosity of the adhesive layer to the aforementioned range. For example, methods such as adjusting the composition, molecular weight (weight average molecular weight (Mw)), molecular weight distribution (weight average molecular weight / number average molecular weight (Mw / Mn)), and degree of crosslinking (gel fraction) of the base polymer contained in the adhesive layer can be used. Similarly, there are no particular limitations on the method for adjusting t / G' to the aforementioned range. Methods such as adjusting the thickness t of the adhesive layer, the shear storage modulus G', the composition, molecular weight (weight average molecular weight (Mw)), molecular weight distribution (weight average molecular weight / number average molecular weight (Mw / Mn)), and degree of crosslinking (gel fraction) of the base polymer contained in the adhesive layer can be used.

[0030] The adhesive layer is not particularly limited, and examples include acrylic adhesive layers, rubber-based adhesive layers, urethane adhesive layers, and polysiloxane adhesive layers. Among these, from the viewpoint of easy adjustment of molecular weight and degree of crosslinking, and excellent heat resistance, weather resistance, and cost, an acrylic adhesive layer containing a (meth)acrylic polymer is preferred.

[0031] The aforementioned (meth)acrylic polymers are polymers containing constituent units derived from (meth)acrylic monomers. The aforementioned (meth)acrylate monomers are not particularly limited, and examples include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, isononyl methacrylate, decyl methacrylate, lauryl methacrylate, isotetradecyl methacrylate, octadecyl methacrylate, isooctadecyl methacrylate, cyclohexyl methacrylate, and isocamphenyl methacrylate. These (meth)acrylate monomers can be used alone or in combination of two or more.

[0032] Preferably, the (meth)acrylate is a homopolymer with a glass transition temperature (Tg) below 0°C (hereinafter also referred to as "(meth)acrylate (a)"). That is, the above-mentioned (meth)acrylate polymer preferably contains constituent units derived from the above-mentioned (meth)acrylate (a). By incorporating such relatively soft constituent units into the aforementioned (meth)acrylic polymer, the ball adhesion of the adhesive layer and the aforementioned t / G' can be easily adjusted to the aforementioned range, thereby improving the peeling performance of the adhesive tape when re-transferring wafer parts and enabling better adhesion of wafer parts when receiving them.

[0033] The glass transfer temperature (Tg) of the aforementioned (meth)acrylate (a) is not particularly limited if it is below 0°C. However, for better peel performance when re-transferring wafer parts and for better adhesion of wafer parts when receiving them, the preferred lower limit is -80°C and the preferred upper limit is -5°C. The preferred lower limit of the aforementioned glass transfer temperature (Tg) is -70°C and the preferred upper limit is -10°C. Additionally, regarding the glass transition temperature (Tg) when forming a homopolymer, for homopolymers with a weight average molecular weight (Mw) of approximately 50 million to 1 million or a degree of polymerization of approximately 500,000 to 10,000, it can be measured using, for example, a differential scanning pyrolysis instrument (manufactured by TA Instruments).

[0034] The aforementioned (meth)acrylate (a) preferably contains an alkyl group having 12 or more carbon atoms and a glass transition temperature (Tg) below 0°C when formed into a homopolymer (hereinafter also referred to as "(meth)acrylate (a-1)"). Furthermore, the aforementioned (meth)acrylate (a) also preferably contains an alkyl group having 7 or more carbon atoms but less than 12 carbon atoms and a glass transition temperature (Tg) below 0°C when formed into a homopolymer (hereinafter also referred to as "(meth)acrylate (a-2)"). By incorporating alkyl groups with relatively long carbon chains into the aforementioned (meth)acrylic polymers, the ball adhesion of the adhesive layer and the aforementioned t / G' can be easily adjusted to a better range. The (meth)acrylate (a) preferably contains both the (meth)acrylate (a-1) and the (meth)acrylate (a-2).

[0035] The aforementioned (meth)acrylate (a-1) is not particularly limited, and among the aforementioned (meth)acrylate monomers, examples include lauryl acrylate (with a Tg of -23°C when formed as a homopolymer) and lauryl methacrylate (with a Tg of -65°C when formed as a homopolymer). Further examples include isotetradecyl acrylate (with a Tg of -56°C when formed as a homopolymer) and isooctadecyl acrylate (with a Tg of -18°C when formed as a homopolymer). Wherein, in terms of the ball adhesion of the aforementioned adhesive layer and the ease with which the aforementioned t / G' can be adjusted to a better range, it is preferable to select at least one from the group consisting of lauryl acrylate, lauryl methacrylate, and isooctadecyl acrylate. More preferably, it is lauryl acrylate, and even more preferably, it is lauryl acrylate.

[0036] The aforementioned (meth)acrylate (a-2) is not particularly limited, and examples include heptyl acrylate (with a Tg of -68°C when forming a homopolymer), 2-ethylhexyl acrylate (with a Tg of -70°C when forming a homopolymer), and octyl acrylate (with a Tg of -65°C when forming a homopolymer). Further examples include isononyl acrylate (with a Tg of -58°C when forming a homopolymer) and isodecanyl acrylate (with a Tg of -62°C when forming a homopolymer). Among these, 2-ethylhexyl acrylate is preferred in terms of the ball adhesion of the adhesive layer and the ease with which the t / G' can be adjusted to a better range.

[0037] In the aforementioned (meth)acrylic polymer, the content of the constituent unit derived from the aforementioned (meth)acrylate (a) is not particularly limited, but a preferred lower limit is 40% by weight. If the content of the aforementioned constituent unit is 40% by weight or more, the ball adhesion of the aforementioned adhesive layer and the aforementioned t / G' can be easily adjusted to a better range, the peel performance of the adhesive tape during re-transfer of wafer parts is further improved, and the wafer parts can be adhered to better when receiving wafer parts. A more preferred lower limit for the content of the aforementioned constituent unit is 42% by weight, and a more preferred lower limit is 45% by weight. There is no particular limit to the content of the above-mentioned constituent units, but the preferred upper limit is 98% by weight, and the more preferred upper limit is 95% by weight.

[0038] The aforementioned (meth)acrylic polymer preferably further contains "a structure derived from a monomer containing a crosslinking functional group". By incorporating the structure of the aforementioned (meth)acrylic polymer derived from monomers containing crosslinking functional groups, the cohesive force of the adhesive layer can be adjusted through the crosslinking of these functional groups. This allows for easy adjustment of the adhesive strength and shear storage modulus G' of the adhesive layer. Consequently, the spherical tack and t / G' of the adhesive layer can be easily adjusted to a better range, resulting in improved peel performance of the adhesive tape during re-transfer of wafer components and better adhesion to wafer components. The crosslinking functional groups may be crosslinked or uncrosslinked, but crosslinking is preferred. However, even in the uncrosslinked state, the cohesive force of the adhesive layer is enhanced due to the interaction between the functional groups.

[0039] Examples of monomers containing crosslinking functional groups include those containing carboxyl, hydroxyl, epoxy, double bond, triple bond, amino, amide, and nitrile groups. These monomers containing crosslinking functional groups can be used alone or in combination of two or more. Preferably, at least one monomer is selected from the group consisting of monomers containing carboxyl and monomers containing hydroxyl groups. Furthermore, monomers containing hydroxyl groups are preferred as they can easily adjust the shear storage modulus G' of the adhesive layer through crosslinking using isocyanate-based crosslinking agents. Furthermore, the monomers containing cross-linking functional groups mentioned above may also contain alkyl, ether, carbonyl, ester, carbonate, amide, urethane, etc.

[0040] Examples of monomers containing carboxyl groups include (meth)acrylic acid and other (meth)acrylic acid monomers. Examples of monomers containing hydroxyl groups include 4-hydroxybutyl (meth)acrylic acid and 2-hydroxyethyl (meth)acrylic acid. Examples of monomers containing epoxy groups include glycidyl (meth)acrylic acid. Examples of monomers containing double bonds include allyl (meth)acrylic acid and hexanediol di(meth)acrylic acid. Examples of monomers containing triacrylic bonds include propargyl (meth)acrylic acid. Examples of monomers containing amide groups include (meth)acrylamide.

[0041] In the aforementioned (meth)acrylic polymers, the content of the monomers with crosslinking functional groups is not particularly limited. From the viewpoint of adjusting the adhesive force and shear storage modulus G' of the adhesive layer, the preferred lower limit of the content of the aforementioned constituent units is 0.1 wt%, and the preferred upper limit is 30 wt%. The more preferred lower limit of the content of the aforementioned constituent units is 0.5 wt%, and the more preferred upper limit is 25 wt%. Furthermore, in the aforementioned (meth)acrylic polymers, the content of the structure derived from the aforementioned monomers containing hydroxyl groups is not particularly limited. From the viewpoint of adjusting the adhesive force and shear storage modulus G' of the aforementioned adhesive layer, the preferred lower limit of the content of the aforementioned constituent units is 1% by weight, and the preferred upper limit is 20% by weight. The more preferred lower limit of the content of the aforementioned constituent units is 3% by weight, and the more preferred upper limit is 10% by weight.

[0042] To obtain the aforementioned (meth)acrylic polymer, a monomer mixture containing the aforementioned (meth)acrylic monomer and the aforementioned monomer containing crosslinking functional groups can be subjected to a free radical reaction in the presence of a polymerization initiator to perform copolymerization. As a method for subjecting the aforementioned monomer mixture to a free radical reaction, i.e., a polymerization method, conventionally known methods can be used, such as solution polymerization (boiling point polymerization or isothermal polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, etc.

[0043] The weight-average molecular weight (Mw) of the aforementioned (meth)acrylic polymer is not particularly limited, but a preferred upper limit is 1 million. If the weight-average molecular weight (Mw) is below 1 million, the aforementioned ball adhesion and t / G' can be easily adjusted to a better range, further improving the peel performance of the adhesive tape when re-transferring wafer parts and allowing for better adhesion of wafer parts. A more preferred upper limit for the aforementioned weight-average molecular weight (Mw) is 950,000, and a further more preferred upper limit is 900,000. There is no particular limitation on the lower limit of the above weight average molecular weight (Mw). From the viewpoint of the adhesion and shape retention of the adhesive layer, the preferred lower limit is 400,000, and the more preferred lower limit is 500,000. Furthermore, the weight-average molecular weight of (meth)acrylic acid polymers can be determined, for example, by conversion to standard polystyrene using GPC (Gel Permeation Chromatography). More specifically, for example, a Waters 2690 Separations Module can be used as the measuring instrument, a Showa Denko G.K.K.K.K.K.K.K.L.G. column can be used, ethyl acetate can be used as the solvent, and the measurement can be performed at a sample flow rate of 1 mL / min and a column temperature of 40°C.

[0044] The adhesive layer mentioned above may also contain tackifying resin. Examples of the aforementioned tackifying resins include rosin resins, hydrogenated rosin resins, terpene resins, terpene phenol resins, lavender-indene resins, alicyclic saturated hydrocarbon resins, C5 petroleum resins, C9 petroleum resins, and C5-C9 copolymer petroleum resins. These tackifying resins can be used alone or in combination of two or more.

[0045] The content of the aforementioned tackifying resin is not particularly limited, but from the viewpoint of further improving the peel performance when re-transferring wafer parts, it is preferable that the aforementioned tackifying resin is not present. When the aforementioned tackifying resin is present, the preferred upper limit is 10 parts by weight relative to 100 parts by weight of the resin (e.g., (meth)acrylic polymer) that is the main component of the adhesive layer. If the content of the aforementioned tackifying resin is 10 parts by weight or less, the peel performance of the adhesive layer when re-transferring wafer parts will be further improved.

[0046] The adhesive layer is preferably cross-linked between the main chains of the resin (e.g., the (meth)acrylic polymer, the tackifying resin, etc.) constituting the adhesive layer by containing a cross-linking agent. The aforementioned crosslinking agents are not particularly limited; for example, isocyanate-based crosslinking agents, etc. Crosslinking agents include methacrylic acid polymers, epoxy crosslinking agents, and metal chelate crosslinking agents. Among these, when the (meth)acrylic acid polymer contains constituent units derived from the monomers containing hydroxyl groups, the shear storage modulus G' of the adhesive layer can be easily adjusted by crosslinking with hydroxyl groups. Therefore, isocyanate crosslinking agents are preferred. The content of the crosslinking agent is preferably 0.01 to 10 parts by weight, and more preferably 0.1 to 7 parts by weight, relative to 100 parts by weight of the resin (e.g., the above-mentioned (meth)acrylic polymer) that is the main component of the adhesive layer.

[0047] The adhesive layer may further contain inorganic fillers such as fuminated silica. By incorporating these inorganic fillers, the cohesiveness of the adhesive layer can be improved.

[0048] The aforementioned adhesive layer may further contain known additives such as plasticizers, resins, surfactants, waxes, and microparticle fillers. These additives may be used alone or in combination of two or more.

[0049] The gel content of the adhesive layer is not particularly limited, but the preferred lower limit is 80% by weight, and the preferred upper limit is 95% by weight. If the gel content is 80% by weight or higher, the adhesive force of the adhesive layer can be adjusted to a relatively low range, and the peel performance of the adhesive tape when re-transferring wafer parts will be further improved. If the gel content is 95% by weight or lower, the shear storage modulus G' of the adhesive layer can be easily adjusted. As a result, the adhesive tape can adhere to the wafer parts better when receiving them. The preferred lower limit of the gel content is 85% by weight, the preferred upper limit is 94% by weight, the even more preferred lower limit is 87% by weight, and the even more preferred upper limit is 93% by weight. In addition, the gel fraction of the adhesive layer can be determined by the following methods. Only 0.1 g of the adhesive layer (adhesive composition) was taken from the adhesive tape and immersed in 50 mL of ethyl acetate. The mixture was then vibrated at 23°C and 200 rpm for 24 hours. After vibration, the ethyl acetate was separated from the swelled adhesive composition by a metal mesh (200 mesh). The separated adhesive composition was dried at 110°C for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel fraction of the adhesive layer was calculated using the following formula. Gel fraction (weight %) = 100 × (W1 - W2) / W0 (W0: initial weight of adhesive composition, W1: weight of adhesive composition including metal mesh after drying, W2: initial weight of metal mesh) However, when the above adhesive composition is not completely dissolved in ethyl acetate, solvents such as toluene, hexane, or water are used instead of ethyl acetate. Specifically, when the adhesive composition contains styrene-based elastic materials, toluene or hexane is used, and when it contains polyvinyl alcohol, hot water at 90°C is used.

[0050] The adhesive tape of the present invention can be an unsupported type without a substrate, but from the viewpoint of easy peeling of the adhesive tape from the support and easy reuse of the support, it is preferable to be a supported type with a substrate. In the case of a supported type, the adhesive tape of the present invention can be a single-sided adhesive tape with an adhesive layer on only one side of the substrate, or it can be a double-sided adhesive tape with an adhesive layer on both sides of the substrate. Furthermore, by attaching the support to the adhesive tape of the present invention, usability is improved. Therefore, the adhesive tape of the present invention is preferably a double-sided adhesive tape, and more preferably a double-sided adhesive tape with adhesive layers on both sides of the substrate. The support is not particularly limited, and can be, for example, glass, quartz substrate, metal plate, etc. When the adhesive tape of the present invention is a double-sided adhesive tape with adhesive layers on both sides of a substrate, the adhesive layers on both sides can be the adhesive layers described above, or one side can be the adhesive layer described above, and the other side (the side in contact with the support, etc.) can be another adhesive layer. There are no particular limitations on the other adhesive layers mentioned above, and conventionally known adhesive layers can be used.

[0051] The aforementioned substrate is not particularly limited. Examples of materials that can be used as the substrate include polyethylene terephthalate (PET), polyethylene naphthalate (BND), polyacetal, polyamide, polycarbonate, polyphenylene ether (PPE), polybutylene terephthalate (PBTE), ultra-high molecular weight polyethylene (UHMWPE), syndiotactic polystyrene (SPS), polyarylate, polyurethane, polyether sulfone, polyphenylene sulfide, polyether ether ketone (PEEK), polyimide, polyetherimide, fluoropolymers, and liquid crystal polymers. Among these, polyethylene terephthalate (PET) and polyethylene naphthalate (BND) are preferred for their excellent heat resistance.

[0052] The thickness of the aforementioned substrate is not particularly limited, but a preferred lower limit is 4 μm and a preferred upper limit is 188 μm. By using a substrate thickness within the aforementioned range, an adhesive tape with moderate strength and excellent usability can be manufactured. A more preferred lower limit for the aforementioned substrate thickness is 50 μm, a more preferred upper limit is 125 μm, a further more preferred lower limit is 75 μm, and a further more preferred upper limit is 100 μm.

[0053] The use of the adhesive tape of the present invention is not particularly limited, but it is preferred to be used to support the part in the step of transferring the part. The aforementioned components are not particularly limited, but are preferably semiconductor devices. Examples of such semiconductor devices include microLED chips and optical chips for image sensors. Among these, microLED chips are preferred. The adhesive tape of this invention is particularly suitable for use as a receiving adhesive tape in the step of transferring a wafer component disposed on an adhesive layer onto the adhesive tape, as shown in FIG. 1. The method for transferring the wafer component onto the adhesive tape of this invention is not particularly limited; for example, laser irradiation can be used. The method for further transferring the wafer component from the adhesive tape of this invention onto other carrier materials or driving circuit boards is not particularly limited; for example, a method of directly laminating other carrier materials with adhesive properties, peeling them off, and then transferring the component can be used, or laser irradiation can be used.

[0054] According to the present invention, an adhesive tape can be provided that can adhere well to the wafer component when receiving it, and can exhibit excellent peeling performance when re-transferring the wafer component, thereby suppressing adhesive residue on the wafer component. Simple Explanation of the Diagram

[0055] [Figure 1] is a cross-sectional view schematically showing an example of the step of transferring a wafer component disposed on an adhesive layer onto an adhesive tape. [Figure 2] is a graph of the adhesive tapes obtained by the embodiments and comparative examples in this specification, with the vertical axis as "y of the spherical adhesion No of the adhesive layer" and the horizontal axis as "t / G'". Implementation

[0056] The following examples further illustrate the nature of the present invention, but the present invention is not limited to these examples.

[0057] (Example 1) (1) Preparation of (meth)acrylic acid polymers 52 parts by weight of ethyl acetate were placed in a reactor equipped with a thermometer, stirrer, and cooling pipe. After nitrogen purging, the reactor was heated to initiate reflux. After the ethyl acetate boiled, 0.08 parts by weight of azobisisobutyronitrile (AIBN) was added as a polymerization initiator after 30 minutes. Over a period of 1 hour and 30 minutes, 89.7 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of 4-hydroxybutyl acrylate, and 0.3 parts by weight of acrylic acid were added dropwise in equal amounts to allow the reaction to proceed. 30 minutes after the addition was completed, 0.1 parts by weight of AIBN was added, and the polymerization reaction was further carried out for 5 hours. Ethyl acetate was then added to the reactor for dilution, and the reactor was simultaneously cooled to obtain a solution of (meth)acrylic acid polymer. The obtained (meth)acrylic polymers were analyzed using a Waters 2690 Separations Module as the instrument, a Showa Denko GPC KF-806L column as the column, and ethyl acetate as the solvent. The weight-average molecular weight was determined at a sample flow rate of 1 mL / min and a column temperature of 40 °C.

[0058] (2) Manufacturing of adhesive tape In the obtained solution of (meth)acrylic polymer, CORONATE L-45 (manufactured by Tosoh Corporation) was added as an isocyanate crosslinking agent at a solid content of 1.7 parts by weight relative to 100 parts by weight of (meth)acrylic polymer, and the mixture was stirred thoroughly to obtain an adhesive solution. The obtained adhesive solution was applied to a 100 μm thick polyethylene terephthalate (PET) film using an applicator to achieve a dry film thickness of 75 μm, and dried at 110°C for 3 minutes to obtain an adhesive tape.

[0059] (3) Determination of gel fraction Only 0.1 g of the adhesive layer (adhesive composition) was taken from the adhesive tape and immersed in 50 mL of ethyl acetate. The mixture was then vibrated at 23°C and 200 rpm for 24 hours. After vibration, the ethyl acetate was separated from the swelled adhesive composition by a metal mesh (#200 mesh). The separated adhesive composition was dried at 110°C for 1 hour. The weight of the dried adhesive composition including the metal mesh was measured, and the gel fraction of the adhesive layer was calculated using the following formula. Gel fraction (weight %) = 100 × (W1 - W2) / W0 (W0: initial weight of adhesive composition, W1: weight of adhesive composition including metal mesh after drying, W2: initial weight of metal mesh)

[0060] (4) Determination of shear storage modulus G' In addition, a 1 mm thick sheet consisting solely of an adhesive layer was prepared. The dynamic viscoelastic spectrum of this adhesive layer from -40 to 140 °C was measured using a viscoelastic spectrometer (IT KEISOKU SEIGYO, DVA-200) at a heating rate of 5 °C / min and 1 Hz in simple heating mode. The storage elastic modulus at 23 °C was taken as the shear storage elastic modulus G' of the adhesive layer at 23 °C and 1 Hz.

[0061] Calculate the ratio t / G' of the adhesive layer thickness t (μm) to the shear storage modulus G' (kPa) of the adhesive layer at 23℃ and 1Hz. Also, calculate the values ​​of -13.366(t / G')+28.94, -13.366(t / G')+60.186, -11.981(t / G')+41.528, -11.981(t / G')+54.572, -5.412(t / G')-15.939, and 5.700(t / G')-5.000.

[0062] (5) Determination of ball viscosity The adhesive layer was tested using a ball tack tester (manufactured by Yasuda Seiki Co., Ltd.) in accordance with JIS Z0237, at an environment of 23°C and 50% relative humidity.

[0063] (Examples 2-32, Comparative Examples 1-8) Except for changes to the composition and weight-average molecular weight of the (meth)acrylic acid polymer and the amount of crosslinking agent as shown in Tables 1-3, the adhesive tape was obtained in the same manner as in Example 1. As crosslinking agents, CORONATE HX (manufactured by Tosoh Corporation), an isocyanate-based crosslinking agent, and TETRAD-C (manufactured by Mitsubishi Gas Chemical Corporation), an epoxy-based crosslinking agent, were also used.

[0064] <Evaluation> The adhesive tapes obtained in the examples and comparative examples were evaluated as follows. The results are shown in Tables 1-3.

[0065] (1) Evaluation of the transfer performance (bonding of wafer components) of wafer components In addition to the obtained adhesive tape, prepare a single-sided adhesive tape for testing. The test single-sided adhesive tape was attached to the Si wafer side of a wafer on which 10 Si wafers (500μm × 500μm square, 50μm thick) were arranged. The wafer was then peeled off, thereby positioning the Si wafers onto the test single-sided adhesive tape. A test single-sided adhesive tape containing Si wafers was aligned with an adhesive tape obtained in the examples or comparative examples. A semiconductor solid-state laser was used to irradiate each Si wafer from the substrate side of the test single-sided adhesive tape with 4W, 4kHz 365nm laser light, peeling off the Si wafers and transferring them onto the adhesive tape. When the adhesive tape held the Si wafers, the case where all 10 Si wafers were attached to the adhesive tape was recorded as "〇〇〇", the case where 9 were attached was recorded as "〇〇", the case where 8 were attached was recorded as "〇", and the case where 7 or fewer Si wafers were attached was recorded as "×", in order to evaluate the transfer performance of the wafer components.

[0066] (2) Re-transfer performance and adhesive residue during re-transfer The obtained adhesive tape is attached to the Si wafer side of a wafer on which 10 Si wafers (500μm × 500μm square, 50μm thick) are arranged. Then, the Si wafers are positioned onto the adhesive tape by peeling off the wafer. With the adhesive surfaces of the adhesive tape containing the Si wafers and the protective tape (6312C, manufactured by Sekisui Chemicals Co., Ltd.) facing each other, a 2kg roller is used to press them together at a speed of 300mm / min, thereby pressing the Si wafers onto the protective tape. Then, by peeling off the protective tape, the Si wafers are peeled off from the adhesive tape, transferring the Si wafers onto the protective tape. The re-transfer performance is evaluated by marking the number of Si wafers that can be transferred from the adhesive tape to the protective tape as "〇〇", the number of Si wafers that can be transferred as "〇", and the number of Si wafers that can be transferred as "×". Furthermore, the surface of the Si wafer peeled off from the adhesive tape was observed under a microscope. Cases where no adhesive residue was observed were marked as "〇", and cases where adhesive residue was observed were marked as "×", in order to evaluate adhesive residue.

[0067] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Adhesive layer (parts by weight) (meth)acrylic polymers BA - - - - - - - 47.5 47.5 42.5 42.5 37.5 37.5 37.5 32.5 2-EHA 89.7 95 95 95 95 47.5 47.5 - - 5 5 10 10 10 15 LA - - - - - 47.5 47.5 47.5 47.5 47.5 47.5 47.5 47.5 47.5 47.5 LMA - - - - - - - - - - - - - - - STAND UP - - - - - - - - - - - - - - - 4-HBA 10 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 AAC 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Crosslinking agent CORONATE L 1.7 1.3 1.9 2.5 1.6 0.9 0.9 0.7 1.9 0.9 1.6 1.2 1.9 0.9 1.6 CORONATE HX - - - - - - - - - - - - - - - TETRAD-C - - - - - - - - - - - - - - - (Meth)acrylic polymers Mw [ten thousand] 55 82 82 82 82 89 89 52 52 85 85 82 82 82 80 Adhesive layer Gel fraction [weight %] 86 89 93 94 89 89 89 80 93 83 90 86 92 82 90 Thickness t [µm] 75 50 50 50 75 50 75 50 50 50 50 50 50 75 50 Shear storage elastic modulus G' [kPa] 52.9 35.9 45.9 48.1 43.0 25.2 25.2 38.1 44.5 34.1 35.3 31.9 32.2 31.0 29.0 Ball viscosity No 10 7 6 5 7 7 8 12 10 10 8 8 6 10 6 t / G' 1.42 1.39 1.09 1.04 1.74 1.98 2.98 1.31 1.12 1.47 1.42 1.57 1.55 2.42 1.72 -13.366(t / G')+28.94 10 10.3 14.4 15.0 5.6 2.4 -10.8 11.4 13.92 9.3 10.0 8.0 8.2 -3.4 5.9 -13.366(t / G')+60.186 41.2 41.6 45.6 46.3 36.9 33.7 20.4 42.6 45.2 40.6 41.3 39.2 39.4 27.8 37.1 -11.981(t / G')+41.528 24.5 24.8 28.5 29.1 20.6 17.8 5.9 25.8 28.1 24.0 24.6 22.7 22.9 12.5 20.9 -11.981(t / G')+54.572 37.6 37.9 41.5 42.1 33.7 30.8 18.9 38.8 41.1 37.0 37.6 35.8 36.0 25.6 33.9 5.412(t / G')-15.939 -8.3 -8.4 -10.0 -10.3 -6.5 -5.2 0.2 -8.8 -9.9 -8.0 -8.3 -7.5 -7.5 -2.8 -6.6 5.700 (t / G') - 5.000 3.1 2.9 1.2 0.9 4.9 6.3 12.0 2.5 1.4 3.4 3.1 3.9 3.9 8.8 4.8 Evaluation Transfer performance of chip components 〇〇 〇 〇 〇 〇〇 〇〇 〇〇〇 〇〇 〇 〇〇 〇 〇〇 〇 〇〇 〇〇 Adhesive residue during re-transfer printing 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 Retransfer performance 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇

[0068] [Table 2] Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Example 24 Example 25 Example 26 Example 27 Example 28 Example 29 Example 30 Example 31 Example 32 Adhesive layer (parts by weight) (meth)acrylic polymers BA 32.5 - - - 50.5 - - - - - - - - - - - - 2-FOUR 15 57.5 57.5 52.5 - - 47.5 37.5 37.5 37.5 37.5 27.5 27.5 27.5 - 27.5 44 DAY 47.5 37.5 37.5 42.5 47.5 47.5 - 57.5 57.5 57.5 57.5 67.5 67.5 67.5 67.5 67.5 50 LMA - - - - - 47.5 - - - - - - - - - - - STAND UP - - - - - - 47.5 - - - - - - - 27.5 - - 4-HBA 4.7 4.7 4.7 4.7 1.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 AAC 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.3 Crosslinking agent CORONATE L 1.9 0.9 0.9 0.9 1.2 0.7 0.7 - - - - - - - - - - CORONATE HX - - - - - - - 1 1.2 1.3 1.7 1 1.2 1.3 1.3 1.3 - TETRAD-C - - - - - - - - - - - - - - - - 5 (Meth)acrylic polymers Mw [ten thousand] 82 54 54 52 75 78 42 80 80 80 80 83 83 83 45 83 86 Adhesive layer Gel fraction [weight %] 92 85 85 84 81 88 86 91 92 92 94 92 92 93 93 93 96 Thickness t [µm] 75 75 80 75 75 75 75 75 75 75 75 75 75 75 75 180 65 Shear storage elastic modulus G' [kPa] 29.8 28.5 28.5 26.8 38.9 23.3 18.5 35.5 44.7 45.8 73.1 37.8 41.7 54.3 35.4 54.3 20.0 Ball viscosity No 8 10 11 8 11 7 6 5 3 3 2 5 3 2 3 2 1 t / G' 2.52 2.63 2.81 2.80 1.93 3.22 4.05 2.11 1.68 1.64 1.03 1.98 1.80 1.38 2.12 3.31 3.25 -13.366(t / G')+28.94 -4.7 -6.2 -8.6 -8.5 3.2 -14.1 -25.2 0.7 6.5 7.1 15.2 2.4 4.9 10.5 0.6 -15.4 -14.5 -13.366(t / G')+60.187 26.5 25.0 22.7 22.8 34.4 17.2 6.0 31.9 37.8 38.3 46.5 33.7 36.1 41.7 31.9 15.9 16.7 -11.981(t / G')+41.528 11.4 10.0 7.9 8.0 18.4 3.0 -7.0 16.2 21.4 21.9 29.2 17.8 20.0 25.0 16.1 1.8 2.6 -11.981(t / G')+54.572 24.4 23.0 20.9 21.0 31.5 16.0 6.0 29.3 34.5 35.0 42.3 30.8 33.0 38.0 29.2 14.9 15.6 5.411(t / G')-15.939 -2.3 -1.7 -0.8 -0.8 -5.5 1.5 6.0 -4.5 -6.9 -7.1 -10.4 -5.2 -6.2 -8.5 -4.5 2.0 1.6 5.700(t / G')-5.000 9.3 10.0 11.0 11.0 6.0 13.3 18.1 7.0 4.6 4.3 0.8 6.3 5.3 2.9 7.1 13.9 13.5 evaluate Transfer performance of chip components 〇〇 〇〇〇 〇〇〇 〇〇〇 〇〇 〇〇〇 〇〇〇 〇〇 〇 〇 〇 〇〇 〇 〇 ○○ 〇〇〇 〇〇 Adhesive residue during re-transfer printing 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 Retransfer performance 〇 〇 〇 〇 〇 〇 〇 〇 ○○ ○○ ○○ 〇 ○○ ○○ ○○ ○○ ○○

[0069] [Table 3] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Adhesive layer (parts by weight) (meth)acrylic polymers BA - - - 47.5 89.7 - - - 2-EHA 89.7 89.7 89.7 47.5 - 95 95 47.5 LA - - - - - - - 47.5 LMA - - - - - - - - ISTA - - - - - - - - 4-HBA 10 10 10 4.7 10 4.7 4.7 4.7 AAc 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Crosslinking agent CORONATE L 1.7 1.7 2.5 0.5 1.5 0.3 0.3 0.3 CORONATE HX - - - - - - - - TETRAD-C - - - - - - - - (Meth)acrylic polymers Mw [ten thousand] 80 80 80 52 155 82 80 89 Adhesive layer Gel fraction [weight %] 86 86 90 88 98 65 65 61 Thickness t [µm] 30 50 50 30 75 75 100 75 Shear storage elastic modulus G' [kPa] 52.9 52.9 58.9 33.5 90.2 43.3 43.3 23.5 Ball viscosity No 6 9 6 10 2 13 14 13 t / G' 0.57 0.95 0.85 0.90 0.83 1.73 2.31 3.19 -13.366(t / G')+28.94 21.4 16.3 17.6 17.0 17.8 5.8 -1.9 -13.7 -13.366(t / G')+60.186 52.6 47.6 48.8 48.2 49.1 37.0 29.3 17.5 -11.981(t / G')+41.528 34.7 30.2 31.4 30.8 31.6 20.8 13.9 3.3 -11.981(t / G')+54.572 47.8 43.2 44.4 43.8 44.6 33.8 26.9 16.3 5.412(t / G')-15.939 -12.9 -10.8 -11.3 -11.1 -11.4 -6.6 -3.4 1.3 5.700(t / G')-5.000 -1.8 0.4 -0.2 0.1 -0.3 4.9 8.2 13.2 evaluate Transfer performance of chip components × × × × × ○○ ○○○ ○○○ Adhesive residue during re-transfer printing 〇 〇 〇 〇 〇 × × × Retransfer performance 〇 〇 〇 〇 ○○ × × ×

[0070] BA: Butyl acrylate 2-EHA: 2-Ethylhexyl acrylate LA: Lauryl acrylate LMA: Lauryl methacrylate ISTA: Isooctadecyl acrylate 4-HBA: 4-Hydroxybutyl acrylate AAc: Acrylic acid [Industrial Applicability]

[0071] According to the present invention, an adhesive tape can be provided that can adhere well to the wafer component when receiving it, and can exhibit excellent peeling performance when re-transferring the wafer component, thereby suppressing adhesive residue on the wafer component.

[0072] 1: Chip components 2: Adhesive layer 3: Substrate 4: Adhesive layer 5: Substrate 8: Adhesive tape 9: Laminate of substrate and adhesive layer

Claims

1. An adhesive tape having an adhesive layer, characterized in that: the adhesive layer contains a (meth)acrylic polymer, the (meth)acrylic polymer contains 40% by weight or more of (meth)acrylic ester constituent units that are formed as homopolymers with a glass transition temperature of 0°C or less, the gel fraction of the adhesive layer is 80% by weight or more and 95% by weight or less, the ball tack of the adhesive layer is No. 12 or less, the ratio of the thickness t (μm) of the adhesive layer to the shear storage modulus G' (kPa) of the adhesive layer at 23°C and 1Hz is t / G' or more, and when the ball tack No of the adhesive layer is y, it satisfies the following formula (2): y ≧-11.981(t / G')+41.528 (2).

2. As in request item 1, the adhesive tape, wherein, The spherical viscosity of the adhesive layer is below No.

4.

3. As in request item 1, the adhesive tape, wherein, The (meth)acrylate that forms a homopolymer with a glass transition temperature below 0°C contains: an alkyl group having 12 or more carbon atoms and a glass transition temperature below 0°C when formed as a homopolymer.

4. As in request item 1, the adhesive tape, wherein, The weight-average molecular weight of this (meth)acrylic polymer is less than 1 million.

5. As in request item 3, the adhesive tape, wherein, The (meth)acrylate having alkyl groups with 12 or more carbon atoms and a glass transition temperature below 0°C when formed as a homopolymer contains lauryl (meth)acrylate.

6. As in request item 1, the adhesive tape, wherein, The (meth)acrylate that forms a homopolymer with a glass transition temperature below 0°C contains: an (meth)acrylate having an alkyl group having 7 or more but less than 12 carbon atoms and having a glass transition temperature (Tg) below 0°C when forming a homopolymer.

7. As in request item 1, the adhesive tape, wherein, The (meth)acrylic polymer contains more than 3% by weight of constituent units derived from monomers containing hydroxyl groups.

8. As in request item 1, the adhesive tape, wherein, The adhesive layer further contains an isocyanate-based crosslinking agent.

9. The adhesive tape as claimed in claim 1 or 2 has a substrate.

10. The adhesive tape, as requested in item 1 or 2, is used in the process of transferring parts to receive the parts.

11. As in request item 10, the adhesive tape, wherein, This part is a semiconductor device.

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