TWI861382B - Adhesive tape - Google Patents

Abstract

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

Description

Adhesive tape

The present invention relates to an adhesive tape mainly used for manufacturing semiconductor devices.

Among the mounting technologies of large scale integrated circuits (LSI), chip size/scale package (CSP) technology has attracted attention. Among them, the package in which the lead terminals are installed inside the package, represented by the quad flat non-leaded package (QFN), is advantageous in terms of miniaturization and high integration. As a manufacturing method for such QFN, the following method can be adopted: multiple QFN semiconductor chips are arranged on the die pad in the package pattern area of the lead frame, and after being sealed in batches with a sealing resin in the mold cavity of the mold, they are cut into individual QFN structures, thereby improving the productivity per unit area of the lead frame.

In the manufacturing method of QFN for batch sealing of multiple semiconductor chips as described above, the area clamped by the mold during resin sealing is only the area outside the resin sealing area that expands outward from the packaging pattern area. Therefore, the sealing resin leaks to the back of the lead frame, which easily causes poor connection caused by burrs generated by the molding resin, or the problem of the terminals of the QFN being covered by the resin. Therefore, in the manufacturing method of QFN, it is considered effective to attach a heat-resistant adhesive tape to the back side of the lead frame, and prevent the resin from leaking to the back side of the lead frame during resin sealing by utilizing the sealing effect of the adhesive force (shielding) of the adhesive tape itself.

In this manufacturing method, the following methods can be adopted: a method of attaching an adhesive tape after mounting a semiconductor chip on a lead frame or after performing wire bonding; or a method of attaching an adhesive tape to the back side (external pad side) of a lead frame in the initial stage, and then performing a sealing step using a sealing resin after a semiconductor chip mounting step or a wire bonding step. For example, Patent Document 1 proposes the following manufacturing method: using a heat-resistant adhesive tape having an adhesive layer, a series of steps such as wire bonding can be performed while preventing resin leakage. In addition, Patent Document 2 discloses an adhesive tape for manufacturing electronic components containing a substrate and an adhesive layer, wherein the adhesive layer contains an adhesive composition containing a phenoxy resin, and reports that the adhesive residue of the adhesive tape or the sealing resin leakage in the resin sealing step can be improved.

[Prior art literature]

[Patent Literature]

Patent document 1: Japanese Patent Publication No. 2002-184801

Patent document 2: Japanese Patent Publication No. 2012-504698

In the manufacture of QFN, after a semiconductor chip is mounted on a lead frame, a wire bonding step 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 of poor connection between the bonding wire and the lead frame, and the wire connection reliability is reduced. The previous adhesive tape cannot be said to have sufficient wire connection reliability in this regard, especially when a pre-plated lead frame (PPF) is used as the lead frame and copper is used as the wire, the reduction in wire connection reliability becomes significant.

The present invention is made in view of the above situation, and its purpose is to provide an adhesive tape with excellent wire connection reliability after the wire bonding step.

The inventors of the present invention have conducted intensive research to solve the above-mentioned problem, and found that an adhesive tape having an adhesive layer containing phenoxy resin, acid anhydride and epoxy resin can solve the above-mentioned problem, thereby completing the present invention.

That is, the present invention is as follows.

[1]

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

[2]

The adhesive tape as described in [1], wherein the storage elastic modulus of the adhesive layer at a temperature above 150°C and below 200°C is below 50 MPa, and the storage elastic modulus at a temperature above 200°C and below 250°C is above 3 MPa.

[3]

The adhesive tape as described in [1] or [2], wherein the storage elastic modulus of the adhesive layer at less than 150°C is 3MPa~10000MPa.

[4]

The adhesive tape as described in any one of [1] to [3], 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 type 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 xanthane skeleton, phenoxy resin containing an adamantane skeleton, and phenoxy resin containing a dicyclopentadiene skeleton.

[5]

The adhesive tape as described in any one of [1] to [4], wherein the glass transition temperature (Tg) of the resin composition constituting the adhesive layer is above 80°C.

[6]

The adhesive tape as described in any one of [1] to [5], wherein the acid anhydride comprises one or more selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides.

[7]

The adhesive tape as described in any one of [1] to [6], wherein the epoxy resin is an epoxy resin having two or more epoxy groups in one molecule.

[8]

An adhesive tape as described in any one of [1] to [7], wherein the adhesive layer further contains a hardening catalyst.

[9]

The adhesive tape described in any one of [1] to [8] can be used to manufacture semiconductor devices.

[10]

The adhesive tape as described in [9], wherein the semiconductor device is a QFN package (Quad Flat Non-leaded Package).

[11]

The adhesive tape as described in [9] or [10] is a pre-adhesive tape that is adhered to the lead frame before the wire bonding step.

According to the present invention, an adhesive tape with excellent wire connection reliability after the wire bonding step can be provided.

1: Adhesive tape

2: Lead frame

3: Semiconductor chip

4:Joining line

5: Sealing resin

10: Semiconductor devices

Figure 1-1 (a) to Figure 1-1 (e) are step diagrams showing an example of a method for manufacturing a semiconductor device using the adhesive tape of the present invention.

Figure 1-2 (f) and Figure 1-2 (g) are step diagrams showing an example of a method for manufacturing a semiconductor device using the adhesive tape of the present invention.

The following is a detailed description of the form used to implement the present invention (hereinafter referred to as "this embodiment"). The following this embodiment is an example used to illustrate the present invention, and the main purpose is not to limit the present invention to the following content. The present invention can be implemented by appropriately deforming within the scope of its main purpose. Furthermore, in this specification, unless otherwise specified, "hardening" not only refers to full hardening but also includes semi-hardening. 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℃~30℃) and can be well adhered to the adherend in a high temperature range (above 100℃).

The adhesive tape of this embodiment has an adhesive layer containing a phenoxy resin, an acid anhydride, and an epoxy resin.

[Phenoxy resin]

From the viewpoint of improving the heat resistance of the cured product and improving the reliability of wire connection in a high temperature region, the resin contained in the adhesive layer of the adhesive tape of the present embodiment can be a phenoxy resin. The phenoxy resin is not particularly limited, and examples thereof include a resin obtained by reacting epihalogen alcohol with a divalent phenol compound, or a resin obtained by reacting a divalent epoxy compound with a divalent phenol compound. As the resin, for example, 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 type 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 xanthane skeleton, phenoxy resin containing an adamantane skeleton, and phenoxy resin containing a dicyclopentadiene skeleton can be cited. Among them, from the perspective of residual rubber, bisphenol A type, bisphenol F type, bisphenol A/F mixed type, bisphenol S type, biphenyl type, naphthalene type phenoxy resins are preferred, and bisphenol A type, bisphenol A/F mixed type, bisphenol S type, biphenyl type phenoxy resins are more preferred.

The weight average molecular weight of the phenoxy resin is not particularly limited, but is preferably 1000-200000, more preferably 5000-100000, and even more preferably 10000-50000. When the weight average molecular weight of the phenoxy resin is 1000-200000, an adhesive layer tends to be stably formed.

The glass transition temperature (Tg) of the phenoxy resin is not particularly limited, but is preferably above 80°C, more preferably above 100°C, and further preferably above 120°C. When the Tg of the phenoxy resin is above 80°C, the reliability of the wired connection tends to be improved.

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 residual adhesive tends to be good, and when it is 80 parts by mass or less, the wired connection reliability tends to be good.

[Anhydride]

The acid anhydride contained in the adhesive layer of the adhesive tape of the present embodiment is not particularly limited, and for example, one or more selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides can be listed.

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.

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-1,2,6,7 -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, 5-(2,5-dioxotetrahydro-3-furanyl)-3methyl-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.

The content of the acid anhydride contained in the adhesive layer is not particularly limited, but is preferably 10 to 25 parts by mass, and 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 phenoxy resin as the main agent tends to be sufficiently cured, and when it is 25 parts by mass or less, the residual adhesive tends to be good.

[Epoxy resin]

The epoxy resin contained in the adhesive layer of the adhesive tape of the present embodiment is not particularly limited if it is a resin having two or more epoxy groups in one molecule. For example, any one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolac type epoxy resin, amine type epoxy resin, biphenyl type epoxy resin, and aliphatic epoxy resin can be used. Among them, from the perspective of residual glue, novolac type epoxy resin and amine type epoxy resin are preferred, and novolac type epoxy resin is more preferred.

The content of the epoxy resin in the adhesive layer is not particularly limited, but is preferably 10 to 45 parts by mass, and 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 phenoxy resin as the main agent tends to be sufficiently cured, and when it is 45 parts by mass or less, the residual adhesive tends to be good.

As an epoxy resin, from the viewpoint of reactivity, the epoxy equivalent is preferably 90g/eq~300g/eq, and more preferably 90g/eq~200g/eq.

[Hardening Catalyst]

The adhesive layer of the adhesive tape of the present embodiment may further contain a hardening catalyst. As a hardening catalyst, it is preferred to use one with an active temperature of 120°C or less. Examples of hardening catalysts include organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl-2-ethylhexanoate peroxide, cumene hydroperoxide, cyclohexanone peroxide, and dicumyl peroxide; imidazole-based initiators such as 2-methylimidazole, N-benzyl-2-methylimidazole, and 2-undecylimidazole; azo-based initiators such as 2,2'-azobis-(2-methylbutyronitrile) and 2,2'-azobisisobutyronitrile; Lewis acid complexes such as boron trifluoride monoethylamine; polyamines; melamine resins, and the like. Among the above, from the perspective of pollution caused by catalyst residues, imidazole-based initiators such as 2-methylimidazole and 2-undecylimidazole are preferred.

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, the reaction tends to start sufficiently, and when it is 3 parts by mass or less, the risk of contamination (residual adhesive) by the adherend tends to be reduced.

[Other ingredients]

The adhesive layer contained in the adhesive tape of this embodiment may further contain other additives in addition to the above. Such other additives include: mold release agent, ultraviolet absorber, adhesion agent, softener, filler, anti-aging agent, pigment, dye, silane coupling agent and other additives.

[Adhesive layer]

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 more than 200°C to 250°C is preferably 3 MPa or more, more preferably 5 MPa or more, and further preferably 10 MPa or more. When the storage elastic coefficient is above 3MPa at a temperature above 200°C and below 250°C, the deformation of the adhesive tape can be suppressed in the above temperature range, and the reliability of wired connection tends to be improved.

Furthermore, from the perspective of handling properties, the storage elastic coefficient of the adhesive layer at a temperature below 150°C is preferably 3MPa~10000MPa, more preferably 5MPa~10000MPa, and further preferably 10MPa~10000MPa.

As a method for adjusting the storage elastic coefficient of the adhesive layer, for example, adjusting the addition ratio of phenoxy resin, epoxy resin and acid anhydride can be listed.

The Tg of the resin composition constituting the adhesive layer of the present embodiment is not particularly limited, but is preferably above 80°C, more preferably above 100°C, and further preferably above 120°C. When the Tg of the resin composition constituting the resin layer is above 80°C, the reliability of the wired connection tends to be improved.

[Adhesive tape]

The adhesive tape of this embodiment is an adhesive tape having an adhesive layer containing the specific component. Here, the adhesive tape may include an adhesive layer and a substrate layer.

For example, the resin composition constituting the adhesive layer of the present embodiment is applied to a substrate (sometimes also referred to as a base film, etc.) to form an adhesive layer, thereby making an adhesive tape.

The thickness of the adhesive layer of the adhesive tape of this embodiment is preferably 3μm~40μm, and more preferably 3μm~20μm. When the thickness of the adhesive layer is 3μm or more, there is a tendency to obtain sufficient sealing in the sealing step. On the other hand, when the thickness is 40μm or less, the adhesive layer will not be damaged by the tightening pressure of the mold, and there is a tendency to stably manufacture the adhesive tape.

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

The material constituting the substrate layer is not particularly limited, and examples thereof include polyethylene terephthalate (PET) substrates, polyimide (PI) substrates, polyamide (PA) substrates, polyethylene naphthalate (PEN) substrates, polyphenylene sulfide (PPS) substrates, etc. Among these, polyimide substrates are preferred from the perspective of heat resistance. In addition, the substrate may be subjected to surface modification treatments such as corona treatment or plasma treatment. This can prevent the physical property changes of the substrate over time or perform various surface modifications.

The adhesive tape of this embodiment can protect the adhesive layer by a release film (separation film) before use. By pre-attaching such a release film, the adhesive force of the adhesive layer can be maintained. There is no particular limitation on the release film, and a known one can be used appropriately. Examples of the release film include polyethylene terephthalate film, polypropylene film, polyethylene film, and release paper that have been subjected to silicone release treatment or fluorine release treatment.

As a method for manufacturing the adhesive tape of the present embodiment, for example, there can be cited a method of forming an adhesive layer on a substrate by preparing a solution in which a resin composition constituting the adhesive layer is dissolved in an organic solvent, applying the solution on a substrate, and drying the solution.

Examples of organic solvents 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 acetylacetate, and ethyl acetylacetate; 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, etc.

The coating method is not particularly limited, and a known method may be used. For example, a die coater, a notched wheel coater, a gravure printing coater, etc. may be used.

[Method for manufacturing semiconductor device]

The adhesive tape of this embodiment is affixed and used to cover the terminal portion when performing resin sealing on electronic parts or semiconductor parts.

Figure 1-1 (a) to Figure 1-1 (e) are step diagrams of an example of a method for manufacturing a semiconductor device using the adhesive tape of the present embodiment. As shown in Figure 1, the method for manufacturing a semiconductor device of the present embodiment includes at least a step of mounting a semiconductor chip 3 and a step of sealing using a sealing resin 5. The method for manufacturing a semiconductor device of the present embodiment may further include a cutting step of cutting the sealed structure.

As shown in (a) to (d) of Figure 1-1, 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 of the lead frame (lower side of the figure).

The so-called lead frame 2 is made of metal such as copper and engraved with a QFN terminal pattern. The electrical contact part is sometimes coated (plated) with materials such as silver, nickel, palladium, and gold. When PPF (Pre-Plated Lead Frame) is used as the lead frame, the effect of the present invention tends to become more significant. The thickness of the lead frame 2 is generally 100μm~300μm. Furthermore, the part that is partially processed to be thinner by etching is not limited to this. The lead frame 2 is preferably arranged neatly with the configuration patterns of each QFN so that it is easy to cut in the subsequent cutting step.

The adhesive tape 1 is preferably at least adhered to the outer side of the packaging pattern area and to the entire circumference of the outer side of the resin sealing area sealed with resin. The lead frame 2 is usually preferably provided with a guide pin hole near the end for positioning during resin sealing, and is adhered to an area that does not block the guide pin hole. In addition, since multiple resin sealing areas are arranged in the long side direction of the lead frame 2, it is preferable to adhere the adhesive tape 1 continuously in a manner that spans these multiple areas.

A semiconductor chip 3, i.e., a silicon wafer/chip as a semiconductor integrated circuit part, is mounted on the lead frame 2 as described above. In order to fix the semiconductor chip 3, a fixing area called a die pad is provided on the lead frame 2, and the bonding (fixing) method to the die pad may use a conductive paste, or various methods such as an adhesive tape and an adhesive may be used. When die bonding is performed using a conductive paste or a thermosetting adhesive, it is generally cured by heating at a temperature of about 150°C to 200°C for about 30 minutes to 90 minutes. In order to remove dirt such as die attach materials and improve wire connectivity or the bonding between molds and frames, the lead frame carrying the semiconductor chip may be subjected to plasma treatment as shown in (c) of FIG. 1-1.

Generally, a wire bonding step is performed next to electrically connect the front end of the terminal portion of the lead frame and the electrode pad on the semiconductor chip using a bonding wire. As shown in (d) of FIG. 1-1 , the wire bonding step is a step of electrically connecting the front end of the terminal portion (inner lead) of the lead frame 2 and 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, among which, when a copper wire is used, the effect of the present invention tends to become more significant. Generally, the wire bonding is performed by combining the vibration energy caused by ultrasonic waves and the compression energy caused by applying pressure under heating to 150°C to 250°C. At this time, the adhesive tape 1 surface adhered to the lead frame 2 can be fixed to the heater block securely by vacuum suction. Furthermore, although the above text shows the case where the semiconductor chip is mounted upward to perform the wiring step, the reflow step is appropriately performed when the semiconductor chip is mounted downward.

As shown in (e) of FIG. 1-1 , the sealing step is a step of sealing the semiconductor chip side on one side by a sealing resin 5. The sealing step is performed to protect the semiconductor chip 3 or the bonding wire 4 mounted on the lead frame 2. A particularly representative method is to use a sealing resin represented by an epoxy resin and mold it in a mold. At this time, generally speaking, a mold including an upper mold and a lower mold having a plurality of mold cavities is used, and a plurality of sealing resins 5 are used to perform the sealing step simultaneously. Specifically, for example, the heating temperature during resin sealing is 170°C to 180°C, and after curing at this temperature for several minutes, a post-mold cure is performed for several hours. Following the sealing step, as shown in (f) of FIG. 1-2 , the adhesive tape attached to the lead frame 2 is peeled off. Furthermore, the adhesive tape 1 is preferably peeled off after molding and before curing.

As shown in (g) of FIG. 1-2 , the cutting step is a step of cutting the sealed structure into individual semiconductor devices 10. Generally speaking, the cutting step can be exemplified by using a rotary cutting blade such as a cutter to cut the cut portion of the sealing resin 5.

Furthermore, the adhesive tape of the present embodiment can be attached to the lead frame before the semiconductor chip mounting step as described above, or can be attached to the lead frame after the semiconductor chip mounting step (after wire bonding) and before the sealing step. From the perspective of making the effect of the present invention more significant, it is preferable to attach the adhesive tape to the lead frame before the semiconductor chip mounting step, especially before the wire bonding step.

[Implementation example]

The present invention is described in more detail by the following embodiments and comparative examples, but the present invention is not limited to the following embodiments in any way.

The evaluation methods and measurement methods are as follows.

<Weight average molecular weight>

Standard polystyrene with an average molecular weight of about 500 to 1 million is used for measurement by gel permeation chromatography (GPC).

<Glass transition temperature (Tg)>

The measurement was carried out by Differential Scanning Calorimeter (DSC).

<Store elastic coefficient>

A sheet sample with a thickness of 100um and the same composition as the adhesive layer of the adhesive tape was prepared, and the storage elastic coefficient E' was measured using a dynamic viscoelasticity measuring device (RSA-G2 manufactured by TA Instruments). The measurement conditions were a heating rate of 10.0℃/min, a temperature range of -50℃~300℃, and a frequency of 1Hz. The storage elastic coefficient E' at 25℃, 100℃, 140℃, 175℃, and 225℃ are shown in Tables 1 and 2. In addition, "cannot be measured" in the table means that the adhesive layer is fully stretched and cannot be measured.

<Line connection reliability>

After attaching the adhesive tape to the lead frame at 240°C×10sec×10MPa, the semiconductor chip was mounted on the die pad of the lead frame using a die adsorbent, and the die adsorbent was hardened by heating at 160°C for 30 minutes. Then, a Φ25μm copper wire (manufactured by Tanaka Kikinzoku Kogyo) was used to bond the electrode of the mounted semiconductor chip to the electrode of the lead frame. At this time, a wire bonder (manufactured by K&S) was used to bond the semiconductor chip at a stage temperature of 200°C, a current of 200mA, a time of 30ms, and a load of 100g.

After wire bonding, visually check whether the wire is connected correctly. In addition, the wire connection strength is measured in the wire pull test. If the wire is connected correctly and the wire pull strength is 5gf or more, the evaluation is "○". On the other hand, if the wire is connected correctly but the wire pull strength is less than 5gf, or if the wire is not connected correctly, the evaluation is "×".

<Residual glue>

After the wire bonding step, sealing is performed. The sealing material is CEL-9200HF9 manufactured by Hitachi Chemical Industries, Ltd., and the sealing is performed using a transfer molding device at a temperature of 175°C, a pressure of 3MPa, and a time of 90sec. Then, the sealing material is hardened 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 residual glue on the mold surface and the lead frame surface. In the case of no residual glue, the evaluation is "○", and in the case of residual glue, the evaluation is "×".

Specifically, the following components are used as the components contained in the resin composition of the embodiments and comparative examples.

[Phenoxy resin]

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

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

[Anhydride]

Trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.)

Phthalic anhydride (manufactured by JFE Chemicals)

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

[Epoxy resin]

Epoxy resin C: phenol novolac type epoxy resin (epoxy equivalent: 210g/eq)

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

[Imidazole]

2-Undecyl imidazole (produced by Shikoku Chemical Industries, Ltd., Curezol C11Z)

[Acrylic resin]

Acrylic resin E: Butyl acrylate-acrylic acid random copolymer (manufactured by Dacheng Fine Chemical Co., Ltd., 1HY-3006Y, Tg: -53℃)

[Isocyanate]

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

[Implementation Example 1]

75 parts by mass of trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.), 60 parts by mass of phenol novolac epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., jER152, epoxy equivalent 210 g/eq), and 0.2 parts by mass of 2-undecyl imidazole (manufactured by Shikoku Chemical Industries, Ltd., Curezol C11Z) were added to 100 parts by mass of phenoxy resin A, and stirred at room temperature to obtain a resin composition.

The obtained resin composition was applied to a polyimide film having a thickness of 25 μm using a die coater so that the thickness after drying was 6 μm, and then dried at 150°C for 5 minutes to obtain an adhesive tape.

Next, the release surface of the release film that has been subjected to release treatment is bonded 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.

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

[Example 2]~[Example 8]

Except that the types and contents of each component contained in the composition forming the adhesive layer were replaced with the types and contents shown in Table 1, the adhesive tape was manufactured by the same method as Example 1, and the various physical properties were evaluated.

[Comparison Example 1]~[Comparison Example 6]

Except that the types and contents of the components contained in the composition forming the adhesive layer were replaced with the types and contents shown in Table 2, the adhesive tape was manufactured by the same method as in Example 1, and the various physical properties were evaluated.

As shown in Table 1 and Table 2, the adhesive tapes of Examples 1 to 8 have excellent wire connection reliability after the wire bonding step. In addition, it can also suppress the residual glue in the tape stripping step.

This application is based on the Japanese patent application (Japanese Patent Application No. 2020-064847) filed with the Japan Patent Office on March 31, 2020, and the contents are incorporated into this application by reference.

[Industrial availability]

The adhesive tape of the present invention has industrial applicability as an adhesive tape that can be used in the manufacture of semiconductor devices.

1: Adhesive tape

2: Lead frame

3: Semiconductor chip

4:Joining line

5: Sealing resin

Claims (11)

An adhesive tape having an adhesive layer comprising a phenoxy resin, an acid anhydride and an epoxy resin, wherein, relative to 100 parts by mass of the adhesive layer, the content of the phenoxy resin is 30 parts by mass to 80 parts by mass, the content of the acid anhydride is 10 parts by mass to 40 parts by mass, and the content of the epoxy resin is 10 parts by mass to 45 parts by mass. The adhesive tape as claimed in claim 1, wherein the storage elastic modulus of the adhesive layer at a temperature above 150°C and below 200°C is below 50 MPa, and the storage elastic modulus at a temperature above 200°C and below 250°C is above 3 MPa. The adhesive tape as described in claim 1 or claim 2, wherein the storage elastic modulus of the adhesive layer at a temperature below 150°C is 3MPa to 10000MPa. The adhesive tape as described in claim 1 or claim 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 xanthane skeleton, phenoxy resin containing an adamantane skeleton, and phenoxy resin containing a dicyclopentadiene skeleton. The adhesive tape as described in claim 1 or claim 2, wherein the glass transition temperature (Tg) of the resin composition constituting the adhesive layer is above 80°C. The adhesive tape as described in claim 1 or claim 2, wherein the acid anhydride comprises one or more selected from the group consisting of monofunctional acid anhydrides and polyfunctional acid anhydrides. An adhesive tape as described in claim 1 or claim 2, wherein the epoxy resin is an epoxy resin having two or more epoxy groups in one molecule. An adhesive tape as described in claim 1 or claim 2, wherein the adhesive layer further contains a hardening catalyst. The adhesive tape as described in claim 1 or claim 2 can be used to manufacture semiconductor devices. An adhesive tape as described in claim 9, wherein the semiconductor device is a quad no-lead package (QFN package). The adhesive tape as described in claim 9 is a pre-adhesive tape that is adhered to the lead frame before the wire bonding step.