JP5799180B1 - Adhesive film for semiconductor bonding - Google Patents

Abstract

In the present invention, when dicing along a scribe line (dicing line) while being bonded to the wafer surface, peeling is unlikely to occur at the interface with the wafer, particularly at the interface with the wafer having an aluminum wiring pattern on the scribe line. An object is to provide an adhesive film for semiconductor bonding. The present invention is an adhesive film for semiconductor bonding to be bonded to a wafer with an aluminum wiring pattern, and (1) the storage elastic modulus at a frequency corresponding to the rotational speed of a dicing blade is 7.5 GPa or less, and / or (2) Adhesion for semiconductor bonding in which the dispersion component (γsd) in the surface free energy γ of the surface to be bonded to the wafer with the aluminum wiring pattern is 30 mJ / m 2 or more, measured using two or more types of measuring reagents with known surface energy It is a film.

Description

In the present invention, when dicing along a scribe line (dicing line) while being bonded to the wafer surface, peeling is unlikely to occur at the interface with the wafer, particularly at the interface with the wafer having an aluminum wiring pattern on the scribe line. The present invention relates to an adhesive film for semiconductor bonding.

2. Description of the Related Art In recent years, flip-chip mounting using a semiconductor chip having bump electrodes made of solder or the like has been attracting attention in order to cope with the further miniaturization and higher integration of semiconductor devices.

In flip chip mounting, a method is generally used in which a protruding electrode of a semiconductor chip and an electrode of another semiconductor chip or a substrate are joined, and then an underfill is injected to perform resin sealing (for example, Patent Document 1).
However, in recent years, semiconductor chips have been miniaturized, and the pitch between electrodes has been narrowed. In addition, the gap between semiconductor chips or between a semiconductor chip and a substrate has been narrowed. Therefore, air is trapped when the underfill is injected, and voids are easily generated.
Therefore, instead of injecting underfill after electrode bonding, a method is used in which a thermosetting adhesive film is attached in advance to a substrate or a semiconductor chip, and electrode bonding and curing of the adhesive film are simultaneously performed by heating. (For example, Patent Document 2).

As a method of attaching an adhesive film to a semiconductor chip in advance, a semiconductor with an adhesive film attached by bonding the adhesive film to the surface of a silicon wafer and dicing along the scribe line (dicing line) from the surface of the adhesive film. A method of obtaining a chip is used. FIG. 1 is a top view schematically showing a region of the silicon wafer surface on which scribe lines are formed. As shown in FIG. 1, scribe lines 2 are formed in a lattice shape on the silicon wafer 1, and semiconductor chips 3 are obtained by dicing along the scribe lines 2. The semiconductor chip 3 is provided with a plurality of protruding electrodes 4.

However, when blade typing is performed from the surface of the adhesive film, peeling may occur at the interface between the adhesive film and the silicon wafer.
In particular, as shown in FIG. 1, when a metal wiring pattern 5 called an accessory and used as an alignment mark or the like is present on the scribe line 2, separation from the adhesive film interface is particularly likely to occur at this portion. There are problems such as a decrease in bonding reliability and mixing of dicing waste into the peeled portion.
Further, when aluminum is present on the outermost surface of the metal wiring pattern 5, aluminum easily forms an oxide film on the surface, and aluminum oxide has a weak adhesion. Therefore, peeling occurs at the interface between the aluminum wiring pattern and the adhesive film. The problem is that it tends to occur.

JP 2010-278334 A JP 2011-29392 A

In the present invention, when dicing along a scribe line (dicing line) while being bonded to the wafer surface, peeling is unlikely to occur at the interface with the wafer, particularly at the interface with the wafer having an aluminum wiring pattern on the scribe line. An object is to provide an adhesive film for semiconductor bonding.

The present invention is an adhesive film for semiconductor bonding to be bonded to a wafer with an aluminum wiring pattern, and (1) the storage elastic modulus at a frequency corresponding to the rotational speed of a dicing blade is 7.5 GPa or less, and / or (2) For semiconductor bonding, wherein the dispersion component (γsd) in the surface free energy γ of the surface to be bonded to the wafer with the aluminum wiring pattern, measured using two or more kinds of measuring reagents with known surface energy, is 30 mJ / m ² or more. It is an adhesive film.
The present invention is described in detail below.

The present inventors have (1) a storage elastic modulus at a frequency corresponding to the number of revolutions of a dicing blade and / or (2) a dispersion in surface free energy γ of an adhesive film for semiconductor bonding to be bonded to a wafer with an aluminum wiring pattern. By adjusting the component (γsd) to a specific range, it has been found that peeling of the adhesive film for semiconductor bonding at the interface with the wafer, particularly the interface with the wafer where the aluminum wiring pattern is present on the scribe line, can be suppressed. It came to complete.

The adhesive film for semiconductor bonding of the present invention is bonded to a wafer with an aluminum wiring pattern.
The wafer with the aluminum wiring pattern is not particularly limited, and examples thereof include a wafer made of a semiconductor such as silicon and gallium arsenide, in which scribe lines are formed in a lattice shape, and the aluminum wiring pattern exists on the scribe line. It is done. A semiconductor chip is obtained by dicing such a wafer along a scribe line. The obtained semiconductor chip is preferably provided with a plurality of protruding electrodes made of solder or the like.

The adhesive film for semiconductor bonding of the present invention comprises (1) a storage elastic modulus at a frequency corresponding to the number of revolutions of a dicing blade is 7.5 GPa or less, and / or (2) a measuring reagent having a known surface energy. The dispersion component (γsd) in the surface free energy γ of the surface to be bonded to the wafer with the aluminum wiring pattern, measured using two or more types, is 30 mJ / m ² or more.
By adjusting the storage elastic modulus at a frequency corresponding to the rotational speed of the dicing blade (1) and / or the dispersion component (γsd) in the surface free energy γ (2) to the above range, It is possible to suppress peeling of the adhesive film for semiconductor bonding at the interface, particularly at the interface with the wafer where the aluminum wiring pattern is present on the scribe line. The adhesive film for semiconductor bonding of the present invention may satisfy both of the above (1) and (2), or may satisfy only one of them.

When the storage elastic modulus at a frequency corresponding to the number of revolutions of the dicing blade in (1) exceeds 7.5 GPa, it is used for semiconductor bonding at the interface with the wafer, particularly at the interface with the wafer where the aluminum wiring pattern exists on the scribe line. The adhesive film is easily peeled off. The storage elastic modulus is preferably 7.4 GPa or less, and more preferably 7.3 GPa or less.
The lower limit of the storage elastic modulus is not particularly limited, but dicing in a state where the semiconductor bonding adhesive film is bonded to the wafer surface, and thereafter, the semiconductor chip having the semiconductor bonding adhesive film bonded thereto is thermocompression bonded to a substrate or the like. In view of this, the preferable lower limit is 3.5 GPa, and the more preferable lower limit is 4.0 GPa. If the storage elastic modulus is less than 3.5 GPa, the machinability during dicing may be reduced.

The storage elastic modulus at a frequency corresponding to the number of revolutions of the dicing blade in (1) above is measured by frequency dispersion using a dynamic viscoelasticity measuring device (for example, DVA-200 manufactured by IT Measurement Control Co., Ltd.) It can be estimated by creating a master curve at a water temperature during dicing (for example, about 5 to 50 ° C.) and reading the storage elastic modulus at a specific frequency on the master curve.
In general, in viscoelasticity measurement, there is a fixed relationship between frequency and temperature (temperature-time conversion rule). For example, a change in temperature is converted into a change in frequency, and the viscosity at a constant temperature is calculated. The frequency dependence of elastic properties can be examined. By this method, viscoelastic characteristics in a wide frequency range that cannot be measured can be predicted as characteristics at an arbitrary temperature.

The frequency corresponding to the rotation speed of the dicing blade is a frequency corresponding to a general rotation speed (unit: rpm) of the dicing blade when performing blade typing with the semiconductor bonding adhesive film bonded to the wafer surface. (Unit Hz), generally 10,000 to 60000 rpm (167 to 1000 Hz in terms of frequency), preferably 20000 to 50000 rpm (333 to 833 Hz in terms of frequency).

When the dispersion component (γsd) in the surface free energy γ of (2) is less than 30 mJ / m ² , bonding for semiconductor bonding at the interface with the wafer, particularly at the interface with the wafer having an aluminum wiring pattern on the scribe line. The film becomes easy to peel. The dispersion component (? Sd) is preferably from 32 mJ / ^{m 2} or more, 35 mJ / ^{m 2} or more is more preferable.
The upper limit of the dispersion component (γsd) is not particularly limited, but dicing in the state where the adhesive film for semiconductor bonding is bonded to the wafer surface, or thereafter, the semiconductor chip having the adhesive film for semiconductor bonding is heated on the substrate or the like. In consideration of pressure bonding, the preferable upper limit is 55 mJ / m ² , and the more preferable upper limit is 50 mJ / m ² .

Although not surface polar component in the free energy γ (γsp) particularly limited, preferable lower limit is 0.01 mJ / ^{m 2,} a preferred upper limit is 5 mJ / ^{m 2.} When the polar component (γsp) exceeds 0.01 mJ / ^{m 2} or less than 5 mJ / ^{m 2,} the polarity difference between the adhesive film and aluminum for a semiconductor junction is increased, the interface with the wafer, particularly aluminum wiring on the scribe line The semiconductor bonding adhesive film may be easily peeled off at the interface with the wafer on which the pattern exists. A more preferable lower limit of the polar component (γsp) is 0.02 mJ / m ² , and a more preferable upper limit is 4 mJ / m ² .

Further, the surface free energy γ can be obtained by the sum of the dispersion component (γsd) and the polar component (γsp). The surface free energy γ is not particularly limited, but a preferred lower limit is 30 mJ / m ² and a preferred upper limit is 55 mJ / m ² . When the surface free energy γ is less than 30 mJ / m ² , the adhesive film for semiconductor bonding may be easily peeled off at the interface with the wafer, particularly at the interface with the wafer having an aluminum wiring pattern on the scribe line. A more preferred lower limit of the surface free energy γ is 35 mJ / ^{m 2,} and more preferable upper limit is 50 mJ / ^{m 2.}

The surface free energy γ, and the dispersion component (γsd) and polar component (γsp) in the surface free energy γ are surfaces to be bonded to the wafer with an aluminum wiring pattern of the adhesive film for semiconductor bonding using a contact angle meter ( The contact angles of two or more kinds of measurement reagents with respect to the solid surface) are measured, and calculated from the obtained contact angles using a geometric average method.
The two or more kinds of measurement reagents are not particularly limited as long as the surface energy is known, and examples thereof include water, diiodomethane, bromonaphthalene, and ethylene glycol. For example, when water and diiodoethane are used as measurement reagents, the surface free energy and the dispersion component (γsd) and polar component (γsp) in the surface free energy γ are based on the following formulas (1) to (3). Can be calculated.

γ = γsd + γsp Formula (1)

72.8 (1 + cos θ _H ) =
^{2 (21.8 × γsd) 1/2 +2} (51.0 × γsp) 1/2 Equation (2)

50.8 (1 + cos θ _I ) =
^{2 (48.5 × γsd) 1/2 +2} (2.3 × γsp) 1/2 Equation (3)

θ _H : contact angle of water with solid surface θ _I : contact angle of diiodomethane with solid surface

In order to adjust the storage elastic modulus at a frequency corresponding to the rotational speed of the dicing blade (1) and / or the dispersion component (γsd) of the surface free energy γ (2) to the above range, the present invention is used. The adhesive film for semiconductor bonding preferably contains a thermosetting resin, a thermosetting agent and a high molecular weight compound, and may contain an inorganic filler, an additive or the like as required. In particular, the content of the liquid component at room temperature (25 ° C.) and the high molecular weight compound having a glass transition temperature (Tg) of 0 ° C. or less is 5 to 15% by weight, or the surface is treated with a silane coupling agent. It is preferable to contain 20 to 60% by weight of the treated inorganic filler.
The liquid component at room temperature (25 ° C.) may be a thermosetting resin, a thermosetting agent, or a high molecular weight compound, and other components (for example, a diluent, a cup Ring agents, additives such as adhesion promoters, etc.) may be used.

The said thermosetting resin is not specifically limited, For example, the compound hardened | cured by reaction, such as addition polymerization, polycondensation, polyaddition, addition condensation, ring-opening polymerization, is mentioned. Specific examples of the thermosetting resin include urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, polybenzimidazole resin, diallyl phthalate resin, xylene resin, alkyl -A benzene resin, an epoxy acrylate resin, a silicon resin, a urethane resin, etc. are mentioned. Especially, an epoxy resin and an acrylic resin are preferable from a viewpoint of ensuring the intensity | strength and joining reliability of the hardened | cured material of the adhesive film for semiconductor joining.

The epoxy resin is not particularly limited. For example, bisphenol type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol AD type and bisphenol S type, novolac type epoxy resins such as phenol novolak type and cresol novolak type, resorcinol type epoxy Resin, aromatic epoxy resin such as trisphenolmethane triglycidyl ether, naphthalene type epoxy resin, fluorene type epoxy resin, dicyclopentadiene type epoxy resin, polyether modified epoxy resin, NBR modified epoxy resin, CTBN modified epoxy resin, and These hydrogenated products can be mentioned. These epoxy resins may be used independently and may use 2 or more types together.

The epoxy resin may be an epoxy resin that is liquid at room temperature, or may be an epoxy resin that is solid at room temperature, or may be used in appropriate combination.
Among the epoxy resins that are liquid at room temperature, commercially available products include, for example, bisphenol A type epoxy resins such as EPICLON 840, 840-S, 850, 850-S, EXA-850CRP (manufactured by DIC), EPICLON 830, Bisphenol F type epoxy resin such as 830-S, EXA-830CRP (above, manufactured by DIC), naphthalene type epoxy resin such as EPICLON HP-4032, HP-4032D (above, manufactured by DIC), EPICLON EXA-7015 (DIC) And hydrogenated bisphenol A type epoxy resin such as EX-252 (manufactured by Nagase ChemteX), resorcinol type epoxy resin such as EX-201 (manufactured by Nagase ChemteX), and the like.

Among the epoxy resins that are solid at room temperature, commercially available products include, for example, bisphenol A type epoxy resins such as EPICLON 860, 10550, and 1055 (manufactured by DIC), and bisphenol S such as EPICLON EXA-1514 (made by DIC). Type epoxy resin, naphthalene type epoxy resin such as EPICLON HP-4700, HP-4710, HP-4770 (manufactured by DIC), dicyclopentadiene type epoxy resin such as EPICLON HP-7200 series (made by DIC), EPICLON Examples thereof include cresol novolak type epoxy resins such as HP-5000 and EXA-9900 (manufactured by DIC).

The said thermosetting agent is not specifically limited, A conventionally well-known thermosetting agent can be suitably selected according to the said thermosetting resin. When an epoxy resin is used as the thermosetting resin, the thermosetting agent may be, for example, an acid anhydride curing agent, a phenol curing agent, an amine curing agent, a latent curing agent such as dicyandiamide, or a cationic catalytic curing. Agents and the like. These thermosetting agents may be used independently and may use 2 or more types together. Of these, an acid anhydride curing agent is preferable because of excellent curing speed, physical properties of the cured product, and the like.

Among the acid anhydride curing agents, commercially available products include, for example, YH-306, YH-307 (above, manufactured by Mitsubishi Chemical Corporation, liquid at normal temperature (25 ° C.)), YH-309 (manufactured by Mitsubishi Chemical Corporation, normal temperature). (Solid at 25 ° C.)).

The content of the thermosetting agent is not particularly limited. When an epoxy resin is used as the thermosetting resin and a thermosetting agent that reacts with an epoxy group in an equal amount is used, the content of the thermosetting agent is for semiconductor bonding. The preferable lower limit with respect to the total amount of epoxy groups contained in the adhesive film is 60 equivalents, and the preferable upper limit is 110 equivalents. When the content is less than 60 equivalents, the adhesive film for semiconductor bonding may not be sufficiently cured. Even if the content exceeds 110 equivalents, it does not contribute particularly to the curability of the adhesive film for semiconductor bonding, and may cause voids due to volatilization of an excessive thermosetting agent. The more preferable lower limit of the content is 70 equivalents, and the more preferable upper limit is 100 equivalents.

The adhesive film for semiconductor bonding of the present invention may further contain a curing accelerator for the purpose of adjusting the curing speed, the physical properties of the cured product, and the like.
The said hardening accelerator is not specifically limited, For example, an imidazole series hardening accelerator, a tertiary amine type hardening accelerator, etc. are mentioned. Of these, an imidazole curing accelerator is preferred because it is easy to control the reaction system for adjusting the curing speed and the physical properties of the cured product.

The imidazole curing accelerator is not particularly limited. For example, Fujicure 7000 (manufactured by T & K TOKA, liquid at room temperature (25 ° C.)), 1-cyanoethyl-2-phenylimidazole in which 1-position of imidazole is protected with a cyanoethyl group, Imidazole-based curing accelerator with basicity protected with isocyanuric acid (trade name “2MA-OK”, manufactured by Shikoku Kasei Kogyo Co., Ltd., solid at room temperature (25 ° C.)), 2MZ, 2MZ-P, 2PZ, 2PZ-PW, 2P4MZ , C11Z-CNS, 2PZ-CNS, 2PZCNS-PW, 2MZ-A, 2MZA-PW, C11Z-A, 2E4MZ-A, 2MAOK-PW, 2PZ-OK, 2MZ-OK, 2PHZ, 2PHZ-PW, 2P4MHZ, 2P4MHZ -PW, 2E4MZ · BIS, VT, VT-OK, MAVT, MAVT-O (Or more, Shikoku Chemicals Co., Ltd.), and the like. These imidazole type hardening accelerators may be used independently and may use 2 or more types together.

Content of the said hardening accelerator is not specifically limited, The preferable minimum with respect to 100 weight part of thermosetting agents is 2 weight part, and a preferable upper limit is 50 weight part. When the content is less than 2 parts by weight, heating for a long time at a high temperature may be required for thermosetting the adhesive film for semiconductor bonding. When the content exceeds 50 parts by weight, the storage stability of the adhesive film for semiconductor bonding may be insufficient, or voids may be caused by excessive volatilization of the curing accelerator. A more preferred lower limit of the content is 3 parts by weight, and a more preferred upper limit is 30 parts by weight.

The high molecular weight compound is not particularly limited. For example, urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, polybenzimidazole resin, diallyl phthalate resin, xylene resin, alkyl -Well-known high molecular weight compounds, such as a benzene resin, an epoxy acrylate resin, a silicon resin, and a urethane resin, are mentioned. Among these, a high molecular weight compound having an epoxy group is preferable.

By adding the high molecular weight compound having an epoxy group, the cured product of the adhesive film for semiconductor bonding exhibits excellent flexibility. That is, the cured product of the adhesive film for semiconductor bonding is excellent in mechanical strength, heat resistance and moisture resistance derived from the epoxy resin as the thermosetting resin, and excellent in the high molecular weight compound having the epoxy group. Since it combines flexibility, it will be excellent in cold-heat cycle resistance, solder reflow resistance, dimensional stability, etc., and will exhibit high joint reliability and high conduction reliability.

The high molecular weight compound having an epoxy group is not particularly limited as long as it is a high molecular weight compound having an epoxy group at the terminal and / or side chain (pendant position). For example, an epoxy group-containing acrylic rubber, an epoxy group-containing butadiene rubber, Examples thereof include bisphenol type high molecular weight epoxy resin, epoxy group-containing phenoxy resin, epoxy group-containing acrylic resin, epoxy group-containing urethane resin, and epoxy group-containing polyester resin. Especially, since the high molecular weight compound containing many epoxy groups can be obtained and the mechanical strength and heat resistance of hardened | cured material will become more excellent, an epoxy group containing acrylic resin is preferable. These high molecular weight compounds having an epoxy group may be used alone or in combination of two or more.

When the high molecular weight compound having an epoxy group, particularly an epoxy group-containing acrylic resin is used as the high molecular weight compound, the preferred lower limit of the weight average molecular weight of the high molecular weight compound having the epoxy group is 10,000, and the preferred upper limit is 1,000,000. It is. When the weight average molecular weight is less than 10,000, the film forming property of the adhesive film for semiconductor bonding may be insufficient, or the flexibility of the cured product of the adhesive film for semiconductor bonding may not be sufficiently improved. . When the weight average molecular weight exceeds 1,000,000, the high molecular weight compound may have a reduced solubility in a solvent and a handleability.

When the high molecular weight compound having an epoxy group, particularly an epoxy group-containing acrylic resin is used as the high molecular weight compound, the preferable lower limit of the epoxy equivalent of the high molecular weight compound having the epoxy group is 200, and the preferable upper limit is 1000. If the epoxy equivalent is less than 200, the flexibility of the cured product of the adhesive film for semiconductor bonding may not be sufficiently improved. If the epoxy equivalent exceeds 1000, the mechanical strength or heat resistance of the cured product of the adhesive film for semiconductor bonding may be insufficient.

Content of the said high molecular weight compound in the adhesive film for semiconductor joining of this invention is not specifically limited, The preferable minimum in the adhesive film for semiconductor joining of this invention is 3 weight%, and a preferable upper limit is 30 weight%. If the content is less than 3% by weight, sufficient reliability against thermal strain may not be obtained. When content exceeds 30 weight%, the heat resistance of the adhesive film for semiconductor joining may fall.

The adhesive film for semiconductor bonding of the present invention may further contain an inorganic filler. When it contains an inorganic filler, it is preferable to contain 20 to 60% by weight of an inorganic filler surface-treated with a silane coupling agent. When the content exceeds 60% by weight, the film-forming property of the adhesive film for semiconductor bonding becomes insufficient, the storage elastic modulus at a frequency corresponding to the number of rotations of the dicing blade increases, and it becomes easy to peel off during dicing. There are things to do. Although the minimum of content of the said inorganic filler in the adhesive film for semiconductor joining of this invention is not specifically limited, From a viewpoint of ensuring the intensity | strength and joining reliability of the hardened | cured material of the adhesive film for semiconductor joining, a preferable minimum is 20 weight%. is there.

The inorganic filler is not particularly limited, and examples thereof include silica, alumina, aluminum nitride, boron nitride, silicon nitride, silicon carbide, magnesium oxide, and zinc oxide. Among them, spherical silica is preferable because of excellent fluidity, and spherical silica surface-treated with a methylsilane coupling agent, a phenylsilane coupling agent, a vinylsilane coupling agent, a methacrylic silane coupling agent, or the like is more preferable. Especially, spherical silica surface-treated with a phenylsilane coupling agent is preferable from the viewpoint of controlling the dispersion component (γsd) in the surface free energy γ. By using the surface-treated spherical silica, the film forming property of the adhesive film for semiconductor bonding can be improved, and the storage elastic modulus and the surface free energy can be adjusted to a predetermined range.

Although the average particle diameter of the said inorganic filler is not specifically limited, About 0.01-1 micrometer is preferable from viewpoints, such as transparency of the adhesive film for semiconductor joining, fluidity | liquidity, joining reliability.
The said inorganic filler may be used independently, and may mix and use a multiple types of inorganic filler.

The adhesive film for semiconductor bonding of the present invention is further provided with an adhesive imparting agent such as a diluent, a thixotropy imparting agent, a solvent, an inorganic ion exchanger, a bleed inhibitor, and an imidazole silane coupling agent, as necessary. Other additives such as an agent and a stress relaxation agent such as rubber particles may be contained.

Although the thickness of the adhesive film for semiconductor bonding of the present invention is not particularly limited, the preferable lower limit is 5 μm, the preferable upper limit is 60 μm, the more preferable lower limit is 10 μm, and the more preferable upper limit is 50 μm.

The method for producing the adhesive film for semiconductor bonding of the present invention is not particularly limited. For example, a predetermined amount of other additives are blended in a thermosetting resin, a thermosetting agent, and a high molecular weight compound as necessary. Examples thereof include a method of coating the obtained resin composition on a release film and drying it to produce a film. The mixing method is not particularly limited, and examples thereof include a method using a homodisper, a universal mixer, a Banbury mixer, a kneader and the like.

The adhesive film for semiconductor bonding of the present invention is bonded to a wafer with an aluminum wiring pattern, and is diced along a scribe line (dicing line) while being bonded to the wafer surface. Thereby, the semiconductor chip which affixed the adhesive film for semiconductor joining of this invention is obtained. The obtained semiconductor chip is thermocompression bonded to a substrate or the like with the adhesive film for semiconductor bonding of the present invention.
The method for bonding the adhesive film for semiconductor bonding of the present invention to the wafer with an aluminum wiring pattern is not particularly limited, and examples thereof include laminating under normal pressure and vacuum laminating. In the case of lamination under normal pressure, air may be involved, but after bonding, heat in a pressurized atmosphere using a pressure curing oven (for example, PCO-083TA (manufactured by NTT Atvans Technology)). The void may be removed.
The dicing method is not particularly limited, and examples thereof include conventionally known blade dicing.

According to the present invention, when dicing along a scribe line (dicing line) while being bonded to the wafer surface, peeling occurs at the interface with the wafer, particularly with the wafer having an aluminum wiring pattern on the scribe line. It is possible to provide an adhesive film for semiconductor bonding that hardly occurs.

It is a top view which shows typically one area | region of the silicon wafer surface in which the scribe line was formed. It is a top view which illustrates typically the evaluation method of the dicing evaluation using the wafer with an aluminum film.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
The materials listed in Table 1 were used. According to the composition shown in Table 2, each material was added to methyl ethyl ketone (MEK) as a solvent, and an adhesive solution was produced by stirring and mixing using a homodisper. The obtained adhesive solution was applied onto a release PET film using an applicator so that the thickness after drying was 20 μm, and dried to produce an adhesive film. Until use, the surface of the obtained adhesive layer was protected with a release PET film (protective film).
Using a dynamic viscoelasticity measuring device (DVA-200 manufactured by IT Measurement & Control Co., Ltd.), step temperature increase was performed in a temperature range of −50 to 130 ° C., and storage elastic modulus was measured in a frequency dispersion mode. A master curve at 23 ° C. was created assuming the water temperature during dicing, and 40000 rpm / 60 = 667 Hz was adopted as the frequency corresponding to the number of revolutions of the dicing blade, and the storage elastic modulus at this frequency was read.
Using a contact angle meter (KSV CAM200 manufactured by KSV Instruments), the contact angle of water and diiodomethane to the surface (solid surface) to be bonded to the wafer with the aluminum wiring pattern of the adhesive film was measured, and from the obtained contact angle, The surface free energy γ, and the dispersion component (γsd) and the polar component (γsp) at the surface free energy γ were calculated using the geometric average method according to the above formulas (1) to (3). 2 μL of water and 3 μL of diiodomethane were dropped, and the contact angle after 30 seconds of dropping was measured.

( Examples 2, 4, and 5, Comparative Examples 1 to 5 )
An adhesive film was obtained in the same manner as in Example 1 except that the composition shown in Table 2 was used.

<Evaluation>
The following evaluation was performed about the adhesive film obtained by the Example and the comparative example. The results are shown in Table 2.

(1) Dicing evaluation using a wafer with an aluminum film A wafer with an aluminum film (8-inch size, thickness 725 μm) was prepared. The aluminum film was formed on the entire surface of the wafer, and an Al—Cu film (5000 ± 10%) was formed on the thermal oxide film (1000 ± 10%). Next, an adhesive film (thickness 20 μm) cut to a size of 50 mm × 50 mm was bonded to the wafer surface at 80 ° C. and a vacuum degree of 100 Pa using a vacuum laminator (ATM-812 manufactured by Takatori).
FIG. 2 is a top view schematically illustrating an evaluation method of dicing evaluation using a wafer with an aluminum film. Using a dicing blade (ZH05-SD4800N1-70 manufactured by DISCO) at a water temperature of 23 ° C., a blade rotation speed of 40000 rpm, and a feed rate of 20 mm / sec, as shown in FIG. The wafer 1 was diced. At this time, the wafer cutting depth was set to 100 μm. The intersection 6 of the wafer incision line is observed with a microscope at 25 locations, and the adhesive film in contact with the incision line is peeled off 4 points (substantially zero), 2 points (several locations), 0 points (occurrence of many) 3 A score was assigned at the level, and the total score was set to points (0 to 100 pt). A determination was made as follows.
X: 0 to 30 pt
Δ: 31-60 pt
○: 61-90 pt
A: 91-100 pt

(2) Dicing evaluation using a wafer with an aluminum wiring pattern Dicing evaluation was performed using a wafer (12 inch size, thickness 100 μm) on which an aluminum wiring pattern was formed on a scribe line. After bonding an adhesive film to the whole wafer surface at 80 ° C. and a vacuum degree of 100 Pa using a vacuum laminator (ATM-812 manufactured by Takatori), using a dicing blade (ZH05-SD4800N1-70 manufactured by DISCO) Dicing was performed by fully cutting the wafer along the scribe line at a water temperature of 23 ° C., a blade rotation speed of 40000 rpm, and a feed rate of 20 mm / sec.
The presence or absence of peeling of the adhesive film was visually observed, and the case where there was a peeled portion was judged as x, and the case where there was no peeled portion was judged as ○.

According to the present invention, when dicing along a scribe line (dicing line) while being bonded to the wafer surface, peeling occurs at the interface with the wafer, particularly with the wafer having an aluminum wiring pattern on the scribe line. It is possible to provide an adhesive film for semiconductor bonding that hardly occurs.

1 Silicon wafer 2 Scribe line 3 Semiconductor chip 4 Protruding electrode 5 Metal wiring pattern 6 Intersection of cut line

Claims (1)

An adhesive film for semiconductor bonding to be bonded to a wafer with an aluminum wiring pattern having an aluminum wiring pattern in which aluminum is present on the outermost surface,
(1) The storage elastic modulus at a frequency corresponding to the number of revolutions of the dicing blade at 23 ° C. is 3.5 GPa or more and 7.5 GPa or less, and
(2) the surface free energy was measured using a known measurement reagent 2 or more, the dispersive component of the surface free energy γ of be bonded face to an aluminum wiring pattern wafer (? Sd) is 35 mJ / m ² or more A characteristic adhesive film for semiconductor bonding.

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