Adhesive tape

Abstract

An adhesive tape having an adhesive layer comprising a phenoxy resin, an acid anhydride and an epoxy resin.

Description

Technical Field

[0001] The present invention relates to an adhesive tape mainly used in the manufacture of semiconductor devices. Background Art

[0002] In the LSI mounting technology, CSP (Chip Size / Scale Package) technology has attracted attention, among which, the package in the form of putting the lead terminal inside the package, represented by QFN (Quad Flat Non-leaded package), is advantageous in terms of miniaturization and high integration. As a manufacturing method of such QFN, the following method is adopted: a plurality of QFN semiconductor chips are arranged on the die pad of the package pattern area of ​​the lead frame, sealed together with a sealing resin in the mold cavity of the mold, and then cut into independent QFN structures, thereby improving the productivity of the lead frame per unit area.

[0003] In the above-mentioned QFN manufacturing method that seals multiple semiconductor chips together, the area clamped by the molding die during resin sealing is only the area outside the resin sealing area that has expanded to the outside of the package pattern area. Therefore, the following problems are likely to occur: the sealing resin leaks out to the back of the lead frame, the burrs generated by the molding resin cause poor connection, and the terminals of the QFN are covered with resin. Therefore, in the QFN manufacturing method, it is believed that it is effective to stick a heat-resistant adhesive tape on the back side of the lead frame and use the sealing effect of the self-adhesive force (masking) of the adhesive tape to prevent the resin from leaking to the back side of the lead frame during resin sealing.

[0004] In such a manufacturing method, the following methods are adopted: a method of laminating an adhesive tape after mounting a semiconductor chip on a lead frame or after performing wire bonding; a method of laminating an adhesive tape to the back side (outer pad surface) of a lead frame in the initial stage, and then performing a sealing process based on a sealing resin via a semiconductor chip mounting process and a wire bonding process. For example, Patent Document 1 proposes a manufacturing method in which a series of processes such as wire bonding can be performed while preventing resin leakage using a heat-resistant adhesive tape having an adhesive layer. In addition, Patent Document 2 discloses an adhesive tape for manufacturing electronic components comprising a substrate and an adhesive layer formed from an adhesive composition containing a phenoxy resin, and reports that the adhesive residue of the adhesive tape and the leakage of the sealing resin in the resin sealing process can be improved.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-184801

[0008] Patent Document 2: Japanese Patent Application No. 2012-504698 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In the manufacture of QFN, after the semiconductor chip is mounted on the lead frame, a wire bonding process is performed to electrically connect the front end of the terminal portion of the lead frame to the electrode pad on the semiconductor chip using a bonding wire. At this time, if the adhesive tape attached to the back of the lead frame is not highly elastic, there is a problem that the connection between the bonding lead and the lead frame is poor, and the reliability of the lead connection is reduced. In this respect, the conventional adhesive tape cannot be said to have sufficient lead connection reliability, especially when using PPF (pre-plated lead frame) as the lead frame and copper as the lead, the reduction in lead connection reliability becomes significant.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive tape having excellent wire connection reliability after a wire bonding step.

[0012] Means for solving problems

[0013] The inventors of the present application have conducted intensive studies to solve the above-mentioned problems and, as a result, have found that a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing a phenoxy resin, an acid anhydride, and an epoxy resin can solve the above-mentioned problems, thereby completing the present invention.

[0014] That is, the present invention is as follows.

[0015] [1] An adhesive tape having an adhesive layer comprising a phenoxy resin, an acid anhydride and an epoxy resin.

[0016] [2] The adhesive tape according to [1] above, wherein the adhesive layer has a storage modulus of 50 MPa or less at 150°C to 200°C, and a storage modulus of 3 MPa or more at a temperature exceeding 200°C and falling below 250°C.

[0017] [3] The pressure-sensitive adhesive tape according to [1] or [2], wherein the pressure-sensitive adhesive layer has a storage elastic modulus of 3 MPa to 10,000 MPa at a temperature lower than 150°C.

[0018] [4] An adhesive tape as described in any one of [1] to [3] above, wherein the phenoxy resin comprises one or more selected from the group consisting of a bisphenol A type phenoxy resin, a bisphenol F type phenoxy resin, a phenoxy resin containing a bisphenol A / F mixed skeleton, a bisphenol S type phenoxy resin, a phenoxy resin containing a naphthalene skeleton, a phenoxy resin containing a fluorene skeleton, a phenoxy resin containing a biphenyl skeleton, a phenoxy resin containing an anthracene skeleton, a phenoxy resin containing a pyrene skeleton, a phenoxy resin containing a xanthene skeleton, a phenoxy resin containing an adamantane skeleton, and a phenoxy resin containing a dicyclopentadiene skeleton.

[0019] [5] The adhesive tape according to any one of [1] to [4] above, wherein the glass transition temperature (Tg) of the resin composition constituting the adhesive layer is 80° C. or higher.

[0020] [6] The pressure-sensitive adhesive tape according to any one of [1] to [5] above, wherein the acid anhydride includes at least one selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides.

[0021] [7] The pressure-sensitive adhesive tape according to any one of [1] to [6] above, wherein the epoxy resin is an epoxy resin having two or more epoxy groups in one molecule.

[0022] [8] The pressure-sensitive adhesive tape according to any one of [1] to [7] above, wherein the pressure-sensitive adhesive layer further contains a curing catalyst.

[0023] [9] The adhesive tape according to any one of [1] to [8] above, which is used for manufacturing a semiconductor device.

[0024]

[10] The adhesive tape according to [9] above, wherein the semiconductor device is a QFN package (quad flat no-lead package).

[0025]

[11] The adhesive tape according to [9] or

[10] above, which is a pre-bonding tape to be bonded to a lead frame before a wire bonding step.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide an adhesive tape having excellent wire connection reliability after a wire bonding step. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] [ Figure 1-1 ] is a process diagram showing an example of a method for manufacturing a semiconductor device using the adhesive tape of the present invention.

[0029] [ Figure 1-2 ] is a process diagram showing an example of a method for manufacturing a semiconductor device using the adhesive tape of the present invention. DETAILED DESCRIPTION

[0030] Hereinafter, the mode for implementing the present invention (hereinafter referred to as "this embodiment") is described in detail. The following this embodiment is an example for illustrating the present invention and is not intended to limit the present invention to the following contents. The present invention can be implemented by appropriately deforming it within the scope of its main purpose. It should be noted that, in this specification, unless otherwise specified, "curing" is not only complete curing, but also includes semi-curing. In addition, in this specification, the so-called "adhesive tape" refers to a tape that does not adhere to the adherend at room temperature (20 to 30°C) and can be well bonded to the adherend in a high temperature range (above 100°C).

[0031] The pressure-sensitive adhesive tape of the present embodiment includes a pressure-sensitive adhesive layer containing a phenoxy resin, an acid anhydride, and an epoxy resin.

[0032] [Phenoxy resin]

[0033] As the resin included in the adhesive layer of the adhesive tape of the present embodiment, from the viewpoint of improving the heat resistance of cured product, improving the reliability of lead connection in high temperature region, phenoxy resin can be used.As phenoxy resin, it is not particularly limited, for example, the resin obtained by the reaction of epihalohydrin and divalent phenol compound or the resin obtained by the reaction of divalent epoxy compound and divalent phenol compound can be enumerated.As above-mentioned resin, for example, the phenoxy resin selected from bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, the phenoxy resin containing bisphenol A / F mixed type skeleton, bisphenol S type phenoxy resin, the phenoxy resin containing naphthalene skeleton, the phenoxy resin containing fluorene skeleton, the phenoxy resin containing biphenyl skeleton, the phenoxy resin containing anthracene skeleton, the phenoxy resin containing pyrene skeleton, the phenoxy resin containing xanthene skeleton, the phenoxy resin containing adamantane skeleton and the phenoxy resin containing dicyclopentadiene skeleton can be enumerated.More than one in the group of composition. Among them, from the viewpoint of residual slurry, bisphenol A type, bisphenol F type, bisphenol A / F mixed type, bisphenol S type, biphenyl type, and naphthalene type phenoxy resins are preferred, and bisphenol A type, bisphenol A / F mixed type, bisphenol S type, and biphenyl type phenoxy resins are more preferred.

[0034] The weight average molecular weight of the phenoxy resin is not particularly limited, but is preferably 1,000 to 200,000, more preferably 5,000 to 100,000, and even more preferably 10,000 to 50,000. When the weight average molecular weight of the phenoxy resin is 1,000 to 200,000, an adhesive layer tends to be stably formed.

[0035] The glass transition temperature (Tg) of the phenoxy resin is not particularly limited, but is preferably 80° C. or higher, more preferably 100° C. or higher, and further preferably 120° C. or higher. When the Tg of the phenoxy resin is 80° C. or higher, wire connection reliability tends to improve.

[0036] The content of the phenoxy resin contained in the adhesive layer is not particularly limited, but is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, and further preferably 50 to 60 parts by mass relative to 100 parts by mass of the adhesive layer. When the content of the phenoxy resin is 30 parts by mass or more, the slurry residue tends to be improved, and when it is 80 parts by mass or less, the lead connection reliability tends to be improved.

[0037] [Anhydride]

[0038] The acid anhydride contained in the adhesive layer of the adhesive tape of the present embodiment is not particularly limited, and examples thereof include one or more selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides.

[0039] As the monofunctional acid anhydride, for example, any one or more selected from the group consisting of trimellitic anhydride, phthalic anhydride, maleic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride can be used.

[0040] As the polyfunctional acid anhydride, for example, pyromellitic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,4,5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, naphthalene-1,2 ... Any one or more selected from the group consisting of 7-tetracarboxylic acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic acid dianhydride, 2,2',3,3'-diphenyltetracarboxylic acid dianhydride, 2,3,3',4'-diphenyltetracarboxylic acid dianhydride, and 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-carboxylic acid dianhydride. Among them, trimellitic anhydride, phthalic anhydride, and maleic anhydride are preferred from the viewpoint of being able to stably form an adhesive layer, and trimellitic anhydride is more preferred.

[0041] The content of the acid anhydride contained in the adhesive layer is not particularly limited, but is preferably 10 to 25 parts by mass, more preferably 15 to 20 parts by mass, relative to 100 parts by mass of the adhesive layer. When the content of the acid anhydride is 10 parts by mass or more, the curing of the phenoxy resin as the main agent tends to be sufficient, and when it is 25 parts by mass or less, the residual slurry tends to be good.

[0042] [Epoxy resin]

[0043] The epoxy resin contained in the adhesive layer of the adhesive tape of the present embodiment is not particularly limited as long as it has two or more epoxy groups in one molecule, and for example, any one or more selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, Novolac epoxy resin, amine epoxy resin, biphenyl epoxy resin, and alicyclic epoxy resin can be used. Among them, from the viewpoint of the residual slurry, Novolac epoxy resin and amine epoxy resin are preferred, and Novolac epoxy resin is more preferred.

[0044] The content of the epoxy resin contained in the adhesive layer is not particularly limited, but is preferably 10 to 45 parts by mass, more preferably 15 to 40 parts by mass, relative to 100 parts by mass of the adhesive layer. When the content of the epoxy resin is 10 parts by mass or more, the curing of the phenoxy resin as the main agent tends to be sufficient, and when it is 45 parts by mass or less, the residual slurry tends to be good.

[0045] As an epoxy resin, from a viewpoint of reactivity, an epoxy equivalent is preferably 90-300 g / eq, and more preferably 90-200 g / eq.

[0046] [Curing catalyst]

[0047] The adhesive layer of the adhesive tape of the present embodiment may further contain a curing catalyst. As a curing catalyst, it is preferred to use a curing catalyst having an active temperature of 120°C or less. As a curing catalyst, for example, organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl peroxy-2-ethylhexanoate, cumene hydroperoxide, cyclohexanone peroxide, diisopropylbenzene peroxide, etc.; imidazole initiators such as 2-methylimidazole, N-benzyl-2-methylimidazole, and 2-undecylimidazole; azo initiators such as 2,2'-azobis(2-methylbutyronitrile) and 2,2'-azobisisobutyronitrile, Lewis acid complexes such as monoethylamine trifluoride, polyamines, melamine resins, etc. Among the above, from the viewpoint of contamination caused by catalyst residues, imidazole initiators such as 2-methylimidazole and 2-undecylimidazole are preferred.

[0048] The content of the curing catalyst contained in the adhesive layer is not particularly limited, but is preferably 0.01 to 3 parts by mass, more preferably 0.05 to 2 parts by mass, and further preferably 0.05 to 1 part by mass relative to 100 parts by mass of the phenoxy resin. When the content of the curing catalyst is 0.01 parts by mass or more, there is a tendency to be able to fully initiate the reaction, and when it is 3 parts by mass or less, there is a tendency to reduce the risk of contamination of the adherend (slurry residue).

[0049] [Other ingredients]

[0050] The adhesive layer included in the adhesive tape of the present embodiment may contain other additives in addition to the above-mentioned components. Such other additives include various additives such as release agents, ultraviolet absorbers, tackifiers, softeners, fillers, antioxidants, pigments, dyes, and silane coupling agents.

[0051] [Adhesive layer]

[0052] The storage modulus of the adhesive layer of the present embodiment is not particularly limited, and the storage modulus at 150°C to 200°C is preferably 50 MPa or less, more preferably 30 MPa or less, and further preferably 20 MPa or less. When the storage modulus at 150°C to 200°C is 50 MPa or less, there is a tendency for the adhesion to the lead frame as the adherend to be improved. In addition, the storage modulus at a temperature exceeding 200°C and below 250°C is preferably 3 MPa or more, preferably 5 MPa or more, and further preferably 10 MPa or more. When the storage modulus at a temperature exceeding 200°C and below 250°C is 3 MPa or more, the deformation of the adhesive tape can be suppressed even in the above-mentioned temperature range, and there is a tendency for the reliability of the lead connection to be improved.

[0053] The storage elastic modulus of the adhesive layer at a temperature lower than 150° C. is preferably 3 to 10,000 MPa, more preferably 5 to 10,000 MPa, and even more preferably 10 to 10,000 MPa from the viewpoint of workability.

[0054] Examples of methods for adjusting the storage elastic modulus of the adhesive layer include adjusting the addition ratio of a phenoxy resin, an epoxy resin, and an acid anhydride.

[0055] The Tg of the resin composition constituting the adhesive layer of the present embodiment is not particularly limited, but is preferably 80° C. or higher, more preferably 100° C. or higher, and further preferably 120° C. or higher. When the Tg of the resin composition constituting the resin layer is 80° C. or higher, the reliability of lead connection tends to improve.

[0056] [Adhesive tape]

[0057] The pressure-sensitive adhesive tape of the present embodiment is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing the above-mentioned specific component. Here, the pressure-sensitive adhesive tape may be composed of a pressure-sensitive adhesive layer and a base material layer.

[0058] For example, the adhesive tape can be formed by applying the resin composition constituting the adhesive layer of the present embodiment onto a substrate (sometimes also referred to as a base film) or the like to form an adhesive layer.

[0059] The thickness of the adhesive layer of the adhesive tape of the present embodiment is preferably 3 to 40 μm, more preferably 3 to 20 μm. When the thickness of the adhesive layer is 3 μm or more, there is a tendency to obtain sufficient sealing in the sealing process. On the other hand, when the thickness is 40 μm or less, there is a tendency that the adhesive layer will not be destroyed by the clamping pressure of the mold, and the adhesive tape can be stably manufactured.

[0060] On the other hand, the thickness of the substrate layer is not particularly limited, but is preferably 5 μm or more from the viewpoint of preventing breakage and cracking, and is more preferably 10 to 100 μm from the viewpoint of handleability.

[0061] As the material constituting the substrate layer, it is not particularly limited, for example, polyethylene terephthalate (PET) based substrate, polyimide (PI) based substrate, polyamide (PA) based substrate, polyethylene naphthalate (PEN) based substrate, polyphenylene sulfide (PPS) based substrate etc. can be cited. Among these, from the viewpoints such as heat resistance, preferably polyimide based substrate. In addition, it is also possible to implement such surface modification treatments as corona treatment, plasma treatment etc. to the substrate. Thus, the prevention of the physical property change of the substrate over time, various surface modifications etc. become possible.

[0062] The adhesive tape of the present embodiment can utilize release film (separation film) etc. to protect the adhesive layer before use.By pre-laminating such release film, the adhesive force of the adhesive layer etc. can be maintained.As release film, it is not particularly limited, and known release film can also be appropriately used.As release film, for example, polyethylene terephthalate film, polypropylene film, polyethylene film, release paper etc. implemented silicone-based release treatment, fluorine-based release treatment can be cited.

[0063] Examples of a method for producing the adhesive tape of the present embodiment include a method of preparing a solution prepared by dissolving a resin composition constituting the adhesive layer in an organic solvent, applying the solution on a substrate, and drying the solution to form an adhesive layer on the substrate.

[0064] Examples of the organic solvent include: alcohols such as methanol and ethanol; glycols such as ethylene glycol and propylene glycol; glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; glycol dialkyl ethers such as ethylene glycol dimethyl ether and ethylene glycol diethyl ether; alkyl esters such as methyl acetate, ethyl acetate, propyl acetate, methyl acetoacetate, and methyl acetoacetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane, cyclohexane, and octane; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; cyclic ethers such as tetrahydrofuran and dioxane; and the like.

[0065] The coating method is not particularly limited, and a known method may be used, for example, a die coater, a comma coater, a gravure coater, etc. may be used.

[0066] [Method for manufacturing semiconductor device]

[0067] The pressure-sensitive adhesive tape of the present embodiment is a pressure-sensitive adhesive tape used for masking a terminal portion when resin-sealing an electronic component or a semiconductor component.

[0068] FIG1 is a process diagram of an example of a method for manufacturing a semiconductor device using an adhesive tape according to the present embodiment. As shown in FIG1 , the method for manufacturing a semiconductor device according to the present embodiment at least includes: a step of mounting a semiconductor chip 3; and a step of sealing with a sealing resin 5. The method for manufacturing a semiconductor device according to the present embodiment may further include a dicing step of cutting the sealed structure.

[0069] As shown in FIGS. 1A to 1D , the mounting step is a step of bonding a semiconductor chip 3 to a die pad of a metal lead frame 2 to which an adhesive tape 1 is attached on the back side (lower side in the figure) of the lead frame.

[0070] The so-called lead frame 2 is a frame with a terminal pattern of QFN engraved on it using a metal such as copper as a raw material, and its electrical contact part is sometimes coated (plated) with raw materials such as silver, nickel, palladium, and gold. When PPF (pre-plated lead frame) is used as the lead frame, there is a tendency that the effect of the present invention becomes more significant. The thickness of the lead frame 2 is usually 100 to 300 μm. It should be noted that the portion that is locally processed to be thinner by etching, etc. is not limited thereto. The lead frame 2 is preferably arranged neatly with the configuration pattern of each QFN in a manner that is easy to cut through the subsequent cutting process.

[0071] The adhesive tape 1 is at least affixed to the outside of the package pattern area, preferably to the area including the entire circumference of the outside of the resin sealing area for resin sealing. The lead frame 2 usually has a guide pin hole near the end for positioning during resin sealing, and it is preferably affixed to an area that does not block the guide pin hole. In addition, since there are multiple resin sealing areas arranged in the longitudinal direction of the lead frame 2, it is preferable to affix the adhesive tape 1 continuously across these multiple areas.

[0072] On the lead frame 2 as described above, a semiconductor chip 3, i.e., a silicon wafer chip as part of a semiconductor integrated circuit, is mounted. In order to fix the semiconductor chip 3 on the lead frame 2, a fixing area called a die pad is provided, and the method of bonding (fixing) to the die pad uses a conductive paste, or various methods such as adhesive tape and adhesive can be used. When a conductive paste, a thermosetting adhesive, etc. are used for die bonding, heat curing is usually performed at a temperature of about 150 to 200°C for about 30 minutes to 90 minutes. In order to remove dirt on chip mounting materials, etc., improve lead connectivity, and adhesion between molds and frames, the lead frame carrying the semiconductor chip can be subjected to a plasma treatment as shown in FIG. 1 (c).

[0073] Usually, a wire bonding process is performed thereafter, that is, the front end of the terminal portion of the lead frame is electrically connected to the electrode pad on the semiconductor chip using a bonding wire. As shown in (d) of Figure 1, the wire bonding process is a process of electrically connecting the front end of the terminal portion (internal wire) of the lead frame 2 to the electrode pad on the semiconductor chip 3 using a bonding wire 4. As the bonding wire 4, for example, a gold wire or an aluminum wire can be used, and when a copper wire is used, there is a tendency that the effect of the present invention becomes more significant. Usually, the wiring is performed by using a combination of ultrasonic vibration energy and pressure-based crimping energy under heating to 150 to 250°C. At this time, the surface of the adhesive tape 1 attached to the lead frame 2 is vacuum-sucked so that it can be firmly fixed to the heating module. It should be noted that the above shows the case where the wiring process is performed by face-up installation of the semiconductor chip. In the case where the semiconductor chip is face-down installation, the reflow process can be appropriately implemented.

[0074] As shown in (e) of FIG. 1 , the sealing process is a process of sealing the semiconductor chip side on one side with a sealing resin 5. The sealing process is implemented to protect the semiconductor chip 3 and the bonding wire 4 mounted on the lead frame 2. In particular, it is representative to use a sealing resin mainly composed of an epoxy resin to form a molding in a mold. At this time, a mold formed by an upper mold and a lower mold having multiple cavities is usually used, and the sealing process is simultaneously implemented using multiple sealing resins 5. Specifically, for example, the heating temperature during resin sealing is 170 to 180°C, and after curing at this temperature for several minutes, post-mold cure is further performed for several hours. Following the sealing process, as shown in (f) of FIG. 1 , the adhesive tape attached to the lead frame 2 is peeled off. It should be noted that the adhesive tape 1 is preferably peeled off before post-mold cure.

[0075] As shown in Fig. 1(g) , the dicing step is a step of cutting the sealed structure into individual semiconductor devices 10. A typical dicing step is to cut the cut portion of the sealing resin 5 using a rotary cutter such as a dicing machine.

[0076] It should be noted that, as described above, the adhesive tape of the present embodiment can be bonded to the lead frame before the semiconductor chip mounting process, or can be bonded to the lead frame after the semiconductor chip mounting process (after wire bonding) and before the sealing process. However, from the perspective that the effect of the present invention becomes more significant, it is preferably a pre-bonded tape that is bonded to the lead frame before the semiconductor chip mounting process, especially before the wire bonding process.

[0077] Example

[0078] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples at all.

[0079] Each evaluation method and measurement method are as follows.

[0080] <Weight average molecular weight>

[0081] The molecular weight was measured by gel permeation chromatography (GPC) using standard polystyrene having an average molecular weight of about 500 to 1,000,000.

[0082] <Glass transition temperature (Tg)>

[0083] The measurement was performed using a differential scanning calorimeter (DSC).

[0084] <Storage modulus>

[0085] A sheet sample with a thickness of 100 μm and the same composition as the adhesive layer of the adhesive tape was prepared, and the storage modulus E' was measured using a dynamic viscoelasticity measuring device (RSA-G2 manufactured by TA Instruments). The measurement conditions were a temperature increase rate of 10.0°C / min in a temperature range of -50 to 300°C, and a frequency of 1 Hz. The storage modulus E' at 25°C, 100°C, 140°C, 175°C, and 225°C are shown in Tables 1 and 2. It should be noted that "cannot be measured" in the table means that the adhesive layer is completely stretched and cannot be measured.

[0086] <Lead connection reliability>

[0087] After the adhesive tape was attached to the lead frame at 240°C × 10 seconds × 10 MPa, the semiconductor chip was mounted on the die pad of the lead frame using a die attach material, and the die attach material was cured by heating at 160°C for 30 minutes. The electrode portion of the mounted semiconductor chip and the electrode portion of the lead frame were wire-bonded using a copper wire (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.). At this time, wire bonding was performed using a wire bonder (manufactured by K&S Co., Ltd.) at a table temperature of 200° C., a current value of 200 mA, a time of 30 ms, and a load of 100 g.

[0088] After wire bonding, visually check whether the wires are properly connected. In addition, the wire connection strength is measured by wire tensile test. The case where the wires are properly connected and the wire tensile strength is 5 gf or more is evaluated as "○". On the other hand, the case where the wires are properly connected but the wire tensile strength is less than 5 gf, or the case where the wires are not properly connected is evaluated as "×".

[0089] <Powder residue>

[0090] After the above-mentioned wire bonding process, sealing is performed. The sealing material is CEL-9200HF9 manufactured by Hitachi Chemical Industries, Ltd., and sealing is performed using a transfer molding device at a temperature of 175°C, a pressure of 3MPa, and a time of 90 seconds. Then, the sealing material is cured at a temperature of 175°C and a time of 6h. Then, the tape is peeled off and a microscope is used to observe whether there is any slurry residue on the molding surface and the lead frame surface. The case where there is no slurry residue is evaluated as "○", and the case where there is slurry residue is evaluated as "×".

[0091] Specifically, the following components were used as the components contained in the resin compositions in Examples and Comparative Examples.

[0092] [Phenoxy resin]

[0093] Phenoxy resin A: Bisphenol A / F mixed phenoxy resin (manufactured by Mitsubishi Chemical Corporation, 1256B40)

[0094] Phenoxy resin B: Bisphenol S type phenoxy resin (manufactured by Mitsubishi Chemical Corporation, YX8100BH30)

[0095] [Anhydride]

[0096] Trimellitic anhydride (Mitsubishi Gas Chemical Company, Inc.)

[0097] Phthalic anhydride (manufactured by JFE Chemical Co., Ltd.)

[0098] Polyfunctional acid anhydride: 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-3-cyclohexene-1,2-carboxylic dianhydride (manufactured by DIC Corporation, B-4400)

[0099] [Epoxy resin]

[0100] Epoxy resin C: Phenol Novolac type epoxy resin (epoxy equivalent: 210g / eq)

[0101] Epoxy resin D: Glycidylamine type tetrafunctional epoxy resin (epoxy equivalent: 100 g / eq)

[0102] [Imidazole]

[0103] 2-Undecyl imidazole (produced by Taisei Fine Chemical Co., Ltd., Curezol C11Z)

[0104] [Acrylic resin]

[0105] Acrylic resin E: Butyl acrylate-acrylic acid random copolymer (manufactured by Dacheng Fine Chemicals Co., Ltd., 1HY-3006Y, Tg: -53°C)

[0106] [Isocyanate]

[0107] Isocyanate F: Hexamethylene diisocyanate (manufactured by Asahi Chemical Industry Co., Ltd., Duranate D201)

[0108] [Example 1]

[0109] To 100 parts by mass of phenoxy resin A, 75 parts by mass of trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Company, Inc.), 60 parts by mass of phenol Novolac type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER152, epoxy equivalent 210 g / eq), and 0.2 parts by mass of 2-undecyl imidazole (manufactured by Taisei Fine Chemical Co., Ltd., Curezol C11Z) were added, and the mixture was stirred at room temperature to obtain a resin composition.

[0110] The obtained resin composition was applied to a polyimide film having a thickness of 25 μm using a die coater so as to have a thickness of 6 μm after drying, and then dried at 150° C. for 5 minutes to obtain a pressure-sensitive adhesive tape.

[0111] Next, the release surface of the release film subjected to the release treatment was attached to the adhesive layer of the adhesive tape by lamination, and heated at 100° C. for 100 hours to obtain an adhesive tape with a release film.

[0112] The obtained pressure-sensitive adhesive tape was used to evaluate various physical properties. The evaluation results are shown in Table 1 (unless otherwise specified, the unit of content in the table represents "parts by mass").

[0113] [Example 2] to [Example 8]

[0114] A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the type and content of each component contained in the pressure-sensitive adhesive layer-forming composition were changed to the type and content shown in Table 1, and various physical properties were evaluated.

[0115] [Comparative Example 1] to [Comparative Example 6]

[0116] An adhesive tape was produced in the same manner as in Example 1 except that the kind and content of each component contained in the adhesive layer-forming composition were changed to the kind and content shown in Table 2, and various physical properties were evaluated.

[0117] [Table 1]

[0118]

[0119] [Table 2]

[0120]

[0121] As shown in Tables 1 and 2, the adhesive tapes of Examples 1 to 8 were excellent in wire connection reliability after the wire bonding step. In addition, it was possible to simultaneously suppress the residual slurry in the tape peeling step.

[0122] This application is based on Japanese Patent Application No. 2020-064847 filed with the Japan Patent Office on March 31, 2020, the contents of which are incorporated herein by reference.

[0123] Industrial Applicability

[0124] The adhesive tape of the present invention has industrial applicability as an adhesive tape used for manufacturing semiconductor devices.

Claims

1. An adhesive tape having an adhesive layer comprising a phenoxy resin, an acid anhydride and an epoxy resin, With respect to 100 parts by mass of the adhesive layer, the content of the phenoxy resin is 30 to 80 parts by mass, the content of the acid anhydride is 10 to 25 parts by mass, and the content of the epoxy resin is 10 to 45 parts by mass.

2. The adhesive tape according to claim 1, wherein The adhesive layer has a storage modulus of 50 MPa or less at a temperature of 150° C. to 200° C., and a storage modulus of 3 MPa or more at a temperature of more than 200° C. to 250° C.

3. The adhesive tape according to claim 1 or 2, wherein: The storage modulus of the adhesive layer at a temperature lower than 150° C. is 3 MPa to 10000 MPa.

4. The adhesive tape according to claim 1 or 2, wherein The phenoxy resin comprises one or more selected from the group consisting of bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, phenoxy resin containing a bisphenol A / F mixed skeleton, bisphenol S type phenoxy resin, phenoxy resin containing a naphthalene skeleton, phenoxy resin containing a fluorene skeleton, phenoxy resin containing a biphenyl skeleton, phenoxy resin containing an anthracene skeleton, phenoxy resin containing a pyrene skeleton, phenoxy resin containing a xanthene skeleton, phenoxy resin containing an adamantane skeleton and phenoxy resin containing a dicyclopentadiene skeleton.

5. The adhesive tape according to claim 1 or 2, wherein The glass transition temperature (Tg) of the resin composition constituting the adhesive layer is 80° C. or higher.

6. The adhesive tape according to claim 1 or 2, wherein: The acid anhydride includes at least one selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides.

7. The adhesive tape according to claim 1 or 2, wherein: The epoxy resin is an epoxy resin having two or more epoxy groups in one molecule.

8. The adhesive tape according to claim 1 or 2, wherein The adhesive layer also contains a curing catalyst.

9. The adhesive tape according to claim 1 or 2, which is used for manufacturing a semiconductor device.

10. The adhesive tape according to claim 9, wherein The semiconductor device is a QFN package, ie, a quad flat no-lead package.

11. The adhesive tape according to claim 9, which is a pre-bonding tape to be bonded to a lead frame before a wire bonding step.

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