Protective adhesive tape for processing semiconductor device

Abstract

The invention relates to the technical field of adhesive tapes, in particular to a semiconductor device processing protection adhesive tape. The protective adhesive tape for processing the semiconductor device sequentially comprises a base material layer and an adhesive layer, the adhesive layer is prepared from an adhesive, and the adhesive comprises the following components: an acrylic copolymer containing a functional monomer with a polar group; an oligomer, wherein the oligomer comprises a polyurethane type oligomer; a curing agent and a photoinitiator, wherein the curing agent is an isocyanate curing agent. The adhesive tape disclosed by the invention has good initial adhesive property and water resistance, the stripping force is obviously reduced after UV illumination, no adhesive residue exists in stripping, and the adhesive tape is suitable for cutting or grinding processing protection of semiconductor devices.

Description

Technical Field

[0001] This invention relates to the field of adhesive tape technology, and in particular to a protective adhesive tape for semiconductor device processing. Background Technology

[0002] In the dicing or grinding process of semiconductor devices (such as wafers), UV-resistant adhesive tape is commonly used to attach and fix the devices. After processing, UV light is used to reduce the adhesiveness of the tape so that it can be peeled off. To avoid damage to the devices caused by the heat generated during processing, cooling water is usually used for rinsing and cooling.

[0003] However, UV anti-adhesion tapes have poor water resistance. Their adhesive properties weaken under cooling water, affecting the fixation of devices and consequently impacting the cutting or grinding accuracy, potentially leading to defective devices. Therefore, while ensuring good initial adhesion and light-induced tack reduction, improving the water resistance of UV anti-adhesion tapes is crucial for guaranteeing the processing yield and reliability of semiconductor devices.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a protective tape for semiconductor device processing. The tape of this invention has good initial adhesion and water resistance, and the peel strength is significantly reduced after UV irradiation. It leaves no residue after peeling and is suitable for protecting semiconductor devices during cutting or grinding.

[0006] To achieve the above-mentioned objectives of the present invention, the present invention provides a protective tape for semiconductor device processing, comprising a substrate layer and an adhesive layer, wherein the adhesive layer is prepared from an adhesive, and the adhesive comprises the following components: An acrylic copolymer, wherein the acrylic copolymer contains a functional monomer having a polar group; Oligomers, including polyurethane oligomers; Curing agent and photoinitiator, wherein the curing agent is an isocyanate-based curing agent.

[0007] Furthermore, based on a total monomer content of 100 wt% for the acrylic copolymer, the content of the functional monomer is 2-20 wt%.

[0008] Furthermore, the glass transition temperature (Tg) of the acrylic copolymer is -30~0℃.

[0009] Furthermore, the amount of the polyurethane oligomer is 10 to 50 parts by weight relative to 100 parts by weight of the acrylic copolymer.

[0010] Furthermore, the oligomers also include bisphenol A oligomers.

[0011] Furthermore, the amount of the bisphenol A oligomer is 0 to 120 parts by weight relative to 100 parts by weight of the acrylic copolymer.

[0012] Furthermore, the hydroxyl value of the bisphenol A oligomer is 10~160 mgKOH / g.

[0013] Furthermore, the hydroxyl value of the polyurethane oligomer is 10~160 mgKOH / g.

[0014] Furthermore, the amount of curing agent used is 0.1 to 5 parts by weight relative to 100 parts by weight of the acrylic copolymer.

[0015] Furthermore, the adhesive also includes a catalyst.

[0016] Furthermore, the amount of catalyst used is 0.1 to 0.5 parts by weight relative to 100 parts by weight of the acrylic copolymer.

[0017] Furthermore, the catalyst is an organotin catalyst.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The semiconductor device processing protective tape of the present invention has an adhesive layer made by introducing polyurethane oligomers into an acrylic copolymer containing functional monomers. The Tg of the acrylic copolymer helps ensure the cohesive strength of the adhesive layer. The polyurethane oligomers introduced on this basis, due to their good wettability, can resist water molecules from entering between the substrate and the adhesive layer, thereby improving the tape's water resistance. Furthermore, the hydroxyl groups of the polyurethane oligomers and the polar groups of the acrylic copolymer can react with the isocyanate groups of the isocyanate curing agent, further enhancing the cohesive strength of the adhesive. This allows the adhesive layer to maintain good wettability and adhesion while possessing good water resistance. When tack reduction is required, double-bond cross-linking polymerization can occur between the oligomers, further enhancing the cohesive strength and causing the adhesive layer to shrink in volume, thus achieving tack reduction. Since no small molecules precipitate, the problem of peeling residue is effectively avoided. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0020] It should be noted that "(meth)acrylic acid" in this invention refers to one or both of methacrylic acid and acrylic acid.

[0021] It should be noted that the weight parts of each component in this invention refer to the solid weight parts of the component, excluding the content of volatile components (such as solvents).

[0022] This invention provides a protective tape for semiconductor device processing, comprising a substrate layer and an adhesive layer, wherein the adhesive layer is prepared from an adhesive comprising the following components: An acrylic copolymer, wherein the acrylic copolymer contains a functional monomer having a polar group; Oligomers, including polyurethane oligomers; Curing agent and photoinitiator, wherein the curing agent is an isocyanate-based curing agent.

[0023] In the adhesive layer of the semiconductor device processing protective tape of the present invention, polyurethane oligomers are introduced into the acrylic copolymer, which achieves a balance between the tape's water resistance and adhesion, and leaves no residue after peeling. The polyurethane oligomers have good wettability, preventing water molecules from entering between the substrate and the adhesive layer, thereby improving the tape's water resistance. The polar groups in the acrylic copolymer and the hydroxyl groups in the polyurethane oligomers can react with the isocyanate groups in the isocyanate curing agent to construct a multi-layer cross-linked network structure, improving the cohesive strength of the adhesive layer, thus achieving a balance between the adhesive's adhesion and water resistance.

[0024] Meanwhile, when viscosity reduction is required, UV light irradiation can induce cross-linking reactions between the double bonds of oligomers, further increasing the cohesive strength of the adhesive layer and causing the adhesive layer to shrink in volume, thereby achieving viscosity reduction. Since no small molecules are precipitated, the problem of peeling residue is effectively avoided.

[0025] In a specific embodiment of the present invention, the Tg of the acrylic copolymer is -30 to 0°C, specifically -30°C, -20°C, -10°C, -5°C, 0°C, or any value between the two extremes, preferably -25 to 0°C. A Tg within the above range is beneficial for ensuring good water resistance of the adhesive layer. If the Tg of the acrylic copolymer is lower than the above range, the cohesive strength of the adhesive layer is poor, and the water resistance decreases; if it is higher than the above range, the wettability of the adhesive layer is insufficient, and it cannot resist the penetration of water molecules, which is also detrimental to water resistance.

[0026] In this invention, the Tg of the acrylic copolymer can be obtained by differential scanning calorimetry (DSC), and the test method is based on the national standard GB / T 19466.2-2004 "Differential Scanning Calorimetry (DSC) for Plastics - Part 2: Determination of Glass Transition Temperature".

[0027] In a specific embodiment of the present invention, the weight-average molecular weight of the acrylic copolymer is 300,000 to 1,000,000 g / mol, specifically 300,000 g / mol, 400,000 g / mol, 500,000 g / mol, 600,000 g / mol, 700,000 g / mol, 800,000 g / mol, 900,000 g / mol, 1,000,000 g / mol, or any value between the two extremes. A weight-average molecular weight within the above range is more conducive to achieving a balance between initial adhesion and cohesive strength in the adhesive.

[0028] In a specific embodiment of the present invention, based on a total weight of 100 wt% of polymeric monomer components in the acrylic copolymer, the acrylic copolymer contains 50 to 75 wt% of hard monomers, specifically 50 wt%, 60 wt%, 70 wt%, 75 wt%, or any value between the two extremes.

[0029] In a specific embodiment of the present invention, the hard monomer includes at least one of isobornyl acrylate (IBOA), methyl methacrylate (MMA), and methyl acrylate (MA).

[0030] In a specific embodiment of the present invention, based on a total weight of 100 wt% of polymeric monomer components in the acrylic copolymer, the acrylic copolymer contains 20 to 40 wt% of soft monomers, specifically 20 wt%, 30 wt%, 40 wt%, or any value between the two extremes.

[0031] In a specific embodiment of the present invention, the soft monomer includes at least one of butyl acrylate, isooctyl acrylate (EHA), and dodecyl acrylate.

[0032] In a specific embodiment of the present invention, based on a total weight of 100 wt% of polymeric monomer components in the acrylic copolymer, the acrylic copolymer contains 2-20 wt% of functional monomers, specifically 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, or any value between the two extremes. Controlling the content of functional monomers in the acrylic copolymer within the above range is more beneficial to improving the water resistance of the adhesive. If the content of functional monomers is too low, the content of polar groups is too low, reducing the sites that can react with the curing agent, resulting in a low degree of crosslinking, which is not conducive to improving water resistance; if the content of functional monomers is too high, the content of polar groups is too high, and the adhesive's excessive polarity is also not conducive to improving water resistance.

[0033] In specific embodiments of the present invention, the polar group includes at least one of carboxyl, hydroxyl, and amino groups, preferably at least one of carboxyl and hydroxyl groups. The functional monomer may specifically include at least one of (meth)acrylic acid, hydroxyethyl acrylate (HEA), hydroxyethyl methacrylate, and hydroxypropyl acrylate.

[0034] The acrylic copolymers of the present invention can be prepared by conventional polymerization methods, such as free radical polymerization.

[0035] In one specific embodiment, the preparation of the acrylic copolymer includes: mixing the monomer components, adding a certain amount of solvent and thermal initiator, heating to initiate polymerization under a protective atmosphere, and obtaining the acrylic copolymer after the reaction is completed.

[0036] In a specific embodiment of the present invention, the thermal initiator may be a conventional initiator, such as an azo initiator or a peroxide initiator; the azo initiator includes, but is not limited to, azobisisobutyronitrile (AIBN), azobisisoheptanenitrile, azobisisovalerate, etc., and the peroxide initiator includes, but is not limited to, benzoyl peroxide, methyl ethyl ketone peroxide, etc.

[0037] In a specific embodiment of the present invention, based on a total weight of 100 parts by weight of monomer components in the acrylic copolymer, the amount of the initiator is 0.1 to 1 part by weight, specifically 0.1, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9, 1 part by weight or any value between the two extremes.

[0038] In a specific embodiment of the present invention, the polymerization reaction temperature is 60-80°C and the polymerization reaction time is 2-10 hours.

[0039] In specific embodiments of the present invention, the solvent can be a conventional organic solvent, including but not limited to ethyl acetate, toluene, etc. The amount of solvent used is not specifically limited and can be adjusted according to the solid content of the acrylic copolymer, which can be 30-45%.

[0040] In a specific embodiment of the present invention, the hydroxyl value of the polyurethane oligomer is 10~160 mgKOH / g, specifically 10 mgKOH / g, 20 mgKOH / g, 30 mgKOH / g, 40 mgKOH / g, 50 mgKOH / g, 60 mgKOH / g, 80 mgKOH / g, 90 mgKOH / g, 100 mgKOH / g, 120 mgKOH / g, 140 mgKOH / g, 160 mgKOH / g, or any value between the two extremes, preferably 30~90 mgKOH / g. In this invention, the hydroxyl value refers to the number of milligrams of KOH consumed per gram of compound, reflecting the hydroxyl content in the compound. The higher the value, the higher the hydroxyl content in the compound; conversely, the lower the value, the lower the hydroxyl content. Controlling the hydroxyl value of the oligomer within the above range not only ensures it has a suitable number of hydroxyl groups to react with the curing agent but also avoids gelation caused by excessively rapid reaction.

[0041] In a specific embodiment of the present invention, the functionality of the polyurethane oligomer is 2 to 10, specifically 2, 4, 6, 8, 10, or any value between the two extremes, preferably 4 to 6. A functionality of the polyurethane oligomer within the above range is beneficial for ensuring that the adhesive layer of the tape has a suitable degree of curing after UV irradiation, facilitating peeling without residue.

[0042] In a specific embodiment of the present invention, the weight-average molecular weight of the polyurethane oligomer is 500~10,000 g / mol, specifically 500 g / mol, 1,000 g / mol, 2,000 g / mol, 4,000 g / mol, 6,000 g / mol, 8,000 g / mol, 10,000 g / mol, or any value between the two extremes. A weight-average molecular weight within the above range is beneficial for the dissolution and dispersion of the polyurethane oligomer in the system, reducing the risk of peeling residue.

[0043] In a specific embodiment of the present invention, the Tg of the polyurethane oligomer is -50 to 60°C, specifically -50°C, -30°C, -20°C, -10°C, 0°C, 20°C, 40°C, 60°C, or any value between these two extremes. With the Tg of the polyurethane oligomer within the above range, it can be combined with acrylic copolymers of different Tg to adapt to the surfaces of different materials to which it is applied.

[0044] In a specific embodiment of the present invention, the amount of polyurethane oligomer in the adhesive is 10-50 parts by weight relative to 100 parts by weight of the acrylic copolymer, specifically 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, or any value between the two extremes. When the Tg of the acrylic copolymer is -30 to 0°C, the adhesive has good structural strength, but its wettability is insufficient. Adding an appropriate amount of polyurethane oligomer with good wetting properties can improve the interfacial properties between the adhesive layer and the substrate, and enhance the water resistance of the adhesive layer.

[0045] In a specific embodiment of the present invention, the polyurethane oligomer includes polyurethane acrylic resin, which can be a commercially available product, such as LuCure produced by Guangzhou Runao Chemical Materials Co., Ltd. ® 5520, hydroxyl value 58 mgKOH / g, functionality 4.

[0046] In a specific embodiment of the present invention, the oligomers further include bisphenol A oligomers.

[0047] In a specific embodiment of the present invention, the amount of bisphenol A oligomer in the adhesive relative to 100 parts by weight of the acrylic copolymer is 0-120 parts by weight, specifically 0 parts by weight, 1 part by weight, 10 parts by weight, 20 parts by weight, 40 parts by weight, 60 parts by weight, 80 parts by weight, 100 parts by weight, 120 parts by weight, or any value between the two extremes. By further introducing bisphenol A oligomers into the adhesive, which already contains a certain amount of polyurethane oligomers, a synergistic improvement in water resistance can be achieved. Because bisphenol A oligomers have a benzene ring structure, they have high structural strength and can effectively improve the adhesive layer's resistance to water molecule penetration, thereby enhancing the tape's water resistance. The polar groups in the acrylic copolymer and the hydroxyl groups in the oligomers can react with the isocyanate groups in the isocyanate curing agent to construct a multi-linked network structure, improving the cohesive strength of the adhesive layer, thus achieving a balance between the adhesiveness and water resistance of the adhesive layer.

[0048] In a specific embodiment of the present invention, the hydroxyl value of the bisphenol A oligomer is 10~160 mgKOH / g, specifically 10 mgKOH / g, 20 mgKOH / g, 30 mgKOH / g, 40 mgKOH / g, 50 mgKOH / g, 60 mgKOH / g, 80 mgKOH / g, 90 mgKOH / g, 100 mgKOH / g, 120 mgKOH / g, 140 mgKOH / g, 160 mgKOH / g, or any value between the two extremes, preferably 30~90 mgKOH / g. Controlling the hydroxyl value of the bisphenol A oligomer within the above range not only ensures that the bisphenol A oligomer has a suitable number of hydroxyl groups to react with the curing agent, but also avoids gelation caused by excessively rapid reaction.

[0049] In a specific embodiment of the present invention, the functionality of the bisphenol A oligomer is 2 to 10, specifically 2, 4, 6, 8, 10, or any value between the two extremes, preferably 4 to 6. A functionality of the bisphenol A oligomer within the above range is beneficial for ensuring that the adhesive layer of the tape has a suitable degree of curing after UV irradiation, facilitating peeling without residue.

[0050] In a specific embodiment of the present invention, the weight-average molecular weight of the bisphenol A oligomer is 500~10,000 g / mol, specifically 500 g / mol, 1,000 g / mol, 2,000 g / mol, 4,000 g / mol, 6,000 g / mol, 8,000 g / mol, 10,000 g / mol, or any value between the two extremes. A weight-average molecular weight of the bisphenol A oligomer within the above range is beneficial for its dissolution and dispersion in the system, reducing the risk of residual adhesive after stripping.

[0051] In a specific embodiment of the present invention, the Tg of the bisphenol A oligomer is -30 to 120°C, specifically -30°C, -20°C, -10°C, 0°C, 20°C, 40°C, 60°C, 80°C, 100°C, 120°C, or any value between these two extremes. With the Tg of the bisphenol A oligomer within the above range, it can be combined with acrylic copolymers of different Tg values ​​to adapt to the surfaces of different materials. For example, when the Tg of the acrylic copolymer is low, an oligomer with a higher Tg can be selected within the above range; when the Tg of the acrylic copolymer is high, an oligomer with a lower Tg can be selected within the above range, thereby ensuring suitable structural strength of the adhesive layer.

[0052] In a specific embodiment of the present invention, the bisphenol A oligomer includes bisphenol A diglycidyl ether acrylate adduct, which can be a commercially available product, such as EPOXYESTER 3000A manufactured by Kyoei Chemical Co., Ltd. of Japan, with a hydroxyl value of 50 mg KOH / g.

[0053] In a specific embodiment of the present invention, the amount of photoinitiator in the adhesive is 1 to 12 parts by weight relative to 100 parts by weight of the acrylic copolymer. Specifically, it can be 1 part by weight, 3 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, or any value between the two extremes, preferably 4 to 8 parts by weight. The appropriate introduction of the photoinitiator can initiate a double-bond cross-linking reaction in the oligomer under UV irradiation, further enhancing the cohesive strength of the adhesive and causing the adhesive layer to cure and shrink, thereby achieving tack reduction. If the amount of photoinitiator is too low, the tack reduction effect after UV irradiation will be insignificant, making peeling difficult; if the amount of photoinitiator is too high, the adhesive will become overly sensitive to light, easily leading to tack reduction failure.

[0054] In specific embodiments of the present invention, the photoinitiator may be a conventional free radical photoinitiator, including but not limited to at least one of 1-hydroxycyclohexylphenyl ketone (photoinitiator 184), trimethylbenzoyl-diphenylphosphine oxide (photoinitiator TPO), and benzoin diethyl ether (photoinitiator 651).

[0055] In a specific embodiment of the present invention, the amount of curing agent in the adhesive is 0.1 to 5 parts by weight relative to 100 parts by weight of the acrylic copolymer, specifically 0.1 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, or any value between the two extremes. The appropriate introduction of an isocyanate-based curing agent allows its isocyanate groups to react with the hydroxyl groups in the acrylic copolymer and oligomers of the adhesive, constructing a multi-layer cross-linked network structure. This improves the cohesive strength of the adhesive, thereby enhancing the structural strength and water resistance of the adhesive layer. If the amount of curing agent is too low, the degree of cross-linking in the system is low, resulting in poor structural strength of the adhesive layer, which is detrimental to improving water resistance. If the amount of curing agent is too high, the structural strength of the adhesive layer is improved, but the wettability is poor, and the interfacial adhesion deteriorates, which is also detrimental to improving water resistance.

[0056] In specific embodiments of the present invention, the curing agent may be a conventional isocyanate curing agent, including but not limited to at least one of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), TDI trimer, HDI trimer and IPDI trimer.

[0057] In a specific embodiment of the present invention, the adhesive further includes a catalyst. The introduction of the catalyst can appropriately increase the rate of cross-linking and curing.

[0058] In a specific embodiment of the present invention, the amount of catalyst in the adhesive relative to 100 parts by weight of the acrylic copolymer is 0.1 to 0.5 parts by weight, specifically 0.1, 0.2, 0.3, 0.4, 0.5 parts by weight, or any value between these two extremes. If the amount of catalyst is too low, the catalytic effect will be insignificant; if the amount of catalyst is too high, it may easily induce side reactions or cause the reaction to be too fast, resulting in gelation.

[0059] In specific embodiments of the present invention, the type of catalyst is not particularly limited, and conventional organotin catalysts can be selected, such as including but not limited to dibutyltin dilaurate (DBTDL).

[0060] In this invention, there are no restrictions on the preparation method of the adhesive, and commonly used preparation methods can be used. This invention provides an optional method for preparing an adhesive, comprising the following steps: mixing an acrylic copolymer, an oligomer, a photoinitiator, a curing agent, and an optional catalyst evenly, allowing it to stand to defoam, thereby obtaining the adhesive to be coated.

[0061] In a specific embodiment of the present invention, a certain amount of solvent may be added during the preparation of the adhesive to promote the uniformity of mixing of the components and facilitate coating. Optionally, the solid content of the adhesive may be 20-30% to ensure that the adhesive has suitable leveling properties. In a specific embodiment of the present invention, the solvent may be a conventional organic solvent, such as those listed above.

[0062] It is understood that, for the convenience of production, transportation, and sales, the adhesive of the present invention only limits the composition of the components and not the form in which the components exist; that is, the components can be mixed together or stored separately. The mixed or separate storage method can be selected according to the actual use.

[0063] In a specific embodiment of the present invention, the thickness of the adhesive layer is 10~40 μm, specifically it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or any value between the two extremes.

[0064] In a specific embodiment of the present invention, the thickness of the substrate layer is 80~150 μm, specifically 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 150 μm or any value between the two extremes.

[0065] In a specific embodiment of the present invention, the modulus of the substrate layer is 50 MPa to 200 MPa, specifically 50 MPa, 80 MPa, 100 MPa, 120 MPa, 150 MPa, 180 MPa, 200 MPa, or any value between these two extremes. The present invention limits the modulus of the substrate layer to this range. If the modulus is too low, the material is too soft and prone to forming film fibers during cutting; if the modulus is too high, the material is too hard, reducing its adhesion to semiconductor devices and affecting the water resistance of the tape.

[0066] In a specific embodiment of the present invention, the substrate layer includes at least one of a polyolefin (PO) film, a polyvinyl chloride (PVC) film, and an ethylene-vinyl acetate copolymer (EVA) film.

[0067] The present invention also provides a method for preparing the above-mentioned tape, comprising the following steps: coating an adhesive onto the surface of a release film and drying it to obtain an adhesive layer; bonding a substrate onto the surface of the adhesive layer and curing it to obtain the tape.

[0068] The coating method is not limited and can be conventional methods such as roller coating, blade coating, or dip coating. The thickness of the release film can be freely selected according to actual needs and is not particularly limited. For example, it can be set to 25-100 μm, specifically 25 μm, 30 μm, 40 μm, 50 μm, 80 μm, 100 μm, or any value between the two extremes.

[0069] In a specific embodiment of the present invention, the drying temperature is 80~120℃ and the time is 2~5 min; the aging temperature is 35~45℃ and the time is 4~6 days.

[0070] The following specific embodiments further illustrate the purpose and advantages of the present invention, but these embodiments should not be regarded as limitations of the present invention. In the following embodiments, 1 g represents 1 part by weight.

[0071] In the following embodiments of the present invention, the Tg test method for the acrylic copolymer is differential scanning calorimetry (DSC).

[0072] Example 1 Preparation of acrylic copolymer: 30 g EHA, 5 g HEA, 60 g MA, 5 g MMA, 0.3 g AIBN and 100 g ethyl acetate were added to a reaction vessel, nitrogen gas was introduced, and then the mixture was heated to 70℃ and reacted for 7 h; then an appropriate amount of ethyl acetate was added to obtain an acrylic copolymer with a Tg of -20℃ and a solid content of 40%.

[0073] 100 g (solid weight) of the acrylic copolymer prepared above, 60 g of bisphenol A oligomer (EPOXYESTER 3000A manufactured by Kyoei Chemical Co., Ltd., hydroxyl value 50 mgKOH / g), and 100 g of polyurethane oligomer (LuCure manufactured by Guangzhou Runao Chemical Materials Co., Ltd.) were added. ® 5520 (hydroxyl value 58 mgKOH / g) 30 g, photoinitiator 184 5 g, isocyanate curing agent (Desmodur manufactured by Covestro) ® 2 g of L 75 and 0.3 g of catalyst DBTDL were added to the reactor and stirred for 30 min under yellow light. A certain amount of ethyl acetate was added and mixed evenly. The mixture was allowed to stand to defoam, and an adhesive with a solid content of 25% was obtained. The adhesive was coated on the surface of a 50 μm thick PET release film and dried in a 90℃ oven for 3 min to form a 20 μm thick adhesive layer. A 150 μm thick PO film treated with corona was laminated on the surface of the adhesive layer and cured in a 40℃ oven for 5 days to obtain the tape.

[0074] Example 2 This embodiment is based on Example 1, with the only difference being the amount of oligomer in the adhesive. The preparation method and solid content are the same as in Example 1, as detailed below: Free of bisphenol A oligomer EPOXYESTER 3000A and polyurethane oligomer LuCure ® 5520 50 g.

[0075] Example 3 This embodiment is based on Example 1, with the only difference being the amount of oligomer in the adhesive. The preparation method and solid content are the same as in Example 1, specifically as follows: 120 g of bisphenol A oligomer EPOXYESTER 3000A and 120 g of polyurethane oligomer LuCure. ® 5520 10 g.

[0076] Example 4 group This example group is based on Example 1, with the only difference being the different amounts of acrylic copolymer monomers used in the adhesive, leading to different Tg values. The preparation method and solid content are the same as in Example 1, with the specific differences as follows: Example 4a: 40 g EHA, 5 g HEA, 50 g MA, 5 g MMA, the Tg of the acrylic copolymer is -30℃; Example 4b: 20 g EHA, 5 g HEA, 60 g MA, 15 g MMA, the Tg of the acrylic copolymer is 0°C; Example 4c: 55 g EHA, 5 g HEA, 35 g MA, 5 g MMA, the Tg of the acrylic copolymer is -40°C; Example 4d: 20 g EHA, 5 g HEA, 40 g MA, 35 g MMA, Tg of acrylic copolymer is 10°C.

[0077] Example 5 group This example group is based on Example 1, with the only difference being the amount of acrylic copolymer monomer in the adhesive. However, the Tg of the acrylic copolymer is -20°C in all examples, and the preparation method and solid content are the same as in Example 1. The specific differences are as follows: Example 5a: 33 g EHA, 2 g HEA, 60 g MA, 5 g MMA; Example 5b: 30 g EHA, 20 g HEA, 45 g MA, 5 g MMA; Example 5c: 34 g EHA, 1 g HEA, 60 g MA, 5 g MMA; Example 5d: 30 g EHA, 25 g HEA, 40 g MA, 5 g MMA.

[0078] Comparative Example 1 This comparative example group was conducted in accordance with Example 1, with the only difference being the amount of polyurethane oligomer in the adhesive. The preparation method and solid content were the same as in Example 1, with the specific differences as follows: Comparative Example 1a: LuCure without polyurethane oligomers ® 5520; Comparative Example 1b: LuCure, a polyurethane oligomer ® 5520, 5 g; Comparative Example 1c: LuCure polyurethane oligomer ® 5520, 60 g.

[0079] Comparative Example 2 This comparative example is based on Example 1, with the only difference being the amount of bisphenol A oligomer in the adhesive. The preparation method and solid content are the same as in Example 1. The specific differences are as follows: 30g of bisphenol A oligomer EPOXYESTER 3000A1.

[0080] Performance testing The tapes prepared in the above embodiments and comparative examples were tested for their initial peel strength, peel strength after UV irradiation to reduce tack, and peel strength after soaking in water for 1 h. The test results are shown in Table 1.

[0081] 180° Peel Strength: The 180° peel strength test was conducted according to the national standard GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tapes". A 25 mm × 300 mm tape was taken, the release film was removed, and the tape was adhered to a clean SUS steel plate surface. It was rolled back and forth twice with a 1 kg stainless steel roller and placed at room temperature (RT, 23±2℃, 50±5%RH) for 20 min to obtain the test sample. Then, the initial peel strength was tested at a peel speed of 300 mm / min and expressed as gf / 25 mm. The test samples were irradiated with an LED UV lamp (wavelength 365 nm) with a radiation energy of 600 MJ, and then the peel force after UV irradiation and detack reduction was tested in the same manner as above. The test samples were placed horizontally in water at room temperature (23±2℃) and soaked for 1 hour. After being removed, the surface moisture was wiped off, and the peel strength after soaking in water for 1 hour was tested in the same manner as above. The peel force attenuation rate is calculated as follows: Peel force attenuation rate = (Initial peel force - Peel force after immersion in water for 1 hour) / Initial peel force × 100% Table 1 Performance test results of different embodiments and comparative examples

[0082] The test results show that the tape of the present invention has good initial adhesion performance, and the peel force decay rate after immersion in water for 1 hour is low (not exceeding 13%), exhibiting good water resistance. After UV de-adhesion, the peel force is significantly reduced, making it suitable for the processing and protection of semiconductor devices.

[0083] The test results of Example 4 show that when the Tg of the acrylic copolymer is below the specified range, the cohesive strength of the adhesive layer is poor and the water resistance decreases; if it is above the specified range, the wettability of the adhesive layer is insufficient and it cannot resist the penetration of water molecules, which is also detrimental to water resistance.

[0084] The test results of Example 5 show that when the amount of functional monomer in the acrylic copolymer is lower than the limit range, the number of groups participating in crosslinking decreases, the degree of crosslinking of the system decreases, and the water resistance decreases. When the amount of functional monomer in the acrylic copolymer is higher than the limit range, the number of groups participating in crosslinking increases, the system is over-crosslinked, the tape surface hardens, the wettability decreases, and too many hydroxyl groups will reduce the water resistance of the tape, resulting in a decrease in the overall water resistance of the tape.

[0085] The test results of Comparative Example 1 show that when the adhesive does not contain polyurethane oligomers or its content is low, the improvement of the wettability of the tape is poor, the tape is harder, and the water resistance is reduced; when its content is high, it affects the adhesion of the tape and leads to a decrease in peel strength.

[0086] The test results of Comparative Example 2 show that when the amount of bisphenol A oligomers in the adhesive is too high, the overall water resistance of the tape decreases due to the presence of excessive polar substances in the system.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective tape for semiconductor device processing, characterized in that, It comprises a substrate layer and an adhesive layer, wherein the adhesive layer is prepared from an adhesive, and the adhesive comprises the following components: An acrylic copolymer, wherein the acrylic copolymer contains a functional monomer having a polar group; Oligomers, including polyurethane oligomers; Curing agent and photoinitiator, wherein the curing agent is an isocyanate-based curing agent.

2. The semiconductor device processing protective tape according to claim 1, characterized in that, Based on a total monomer content of 100 wt% for the acrylic copolymer, the content of the functional monomer is 2-20 wt%.

3. The semiconductor device processing protective tape according to claim 1 or 2, characterized in that, The glass transition temperature of the acrylic copolymer is -30~0℃.

4. The semiconductor device processing protective tape according to claim 3, characterized in that, The amount of the polyurethane oligomer is 10 to 50 parts by weight relative to 100 parts by weight of the acrylic copolymer.

5. The semiconductor device processing protective tape according to claim 4, characterized in that, The oligomer also includes bisphenol A oligomers, and the amount of bisphenol A oligomers used is 0 to 120 parts by weight relative to 100 parts by weight of the acrylic copolymer.

6. The semiconductor device processing protective tape according to claim 1, characterized in that, The hydroxyl value of the polyurethane oligomer is 10~160 mgKOH / g.

7. The semiconductor device processing protective tape according to claim 5, characterized in that, The hydroxyl value of the bisphenol A oligomer is 10~160 mgKOH / g.

8. The semiconductor device processing protective tape according to claim 1, characterized in that, The amount of curing agent used is 0.1 to 5 parts by weight relative to 100 parts by weight of the acrylic copolymer.

9. The semiconductor device processing protective tape according to claim 1, characterized in that, The adhesive also includes a catalyst; The amount of catalyst used is 0.1 to 0.5 parts by weight relative to 100 parts by weight of the acrylic copolymer.

10. The semiconductor device processing protective tape according to claim 9, characterized in that, The catalyst is an organotin catalyst.

Images