JP2020088118A - Film adhesive, adhesive sheet, semiconductor device, and manufacturing method thereof - Google Patents

Abstract

To provide a film adhesive capable of sufficiently suppressing defects caused by movement of copper ions in an adhesive.SOLUTION: In a film adhesive for bonding a semiconductor element and a supporting member on which the semiconductor element is mounted, the film adhesive contains a thermosetting resin component and an inorganic filler, and the inorganic filler is surface-treated with a vinylsilane coupling agent and an alkylsilane coupling agent.SELECTED DRAWING: Figure 1

Description

The present invention relates to a film adhesive, an adhesive sheet, a semiconductor device and a method for manufacturing the same.

2. Description of the Related Art In recent years, a stacked MCP (Multi Chip Package) in which semiconductor elements (semiconductor chips) are stacked in multiple stages has become widespread, and is mounted as a memory semiconductor package or the like for mobile phones and mobile audio devices. In addition, with the multi-functionalization of mobile phones and the like, the speeding up, densification, and high integration of semiconductor packages are being promoted. Along with this, the speed has been increased by using copper as the wiring material of the semiconductor chip circuit. In addition, lead frames and the like made of copper are being used from the viewpoint of improving the reliability of connection to a complicated mounting board and accelerating the exhaust heat from the semiconductor package.

However, since the copper has a characteristic of being easily corroded and the coating material for ensuring the insulation property of the circuit surface tends to be simplified from the viewpoint of cost reduction, the semiconductor package has an electrical characteristic. Tends to be difficult to secure. In particular, in a semiconductor package in which semiconductor chips are stacked in multiple stages, copper ions generated by corrosion move inside the adhesive, and electrical signal loss tends to occur within the semiconductor chips or between semiconductor chips.

In addition, from the viewpoint of high functionality, semiconductor elements are often connected to complicated mounting boards, and lead frames made of copper tend to be preferred in order to improve connection reliability. Even in such a case, the loss of the electric signal due to the copper ions generated from the lead frame may be a problem.

Further, in a semiconductor package using a member made of copper as a material, copper ions are likely to be generated from the member, causing an electrical problem, and sufficient HAST resistance may not be obtained.

From the viewpoint of preventing loss of electric signals and the like, studies have been conducted on an adhesive agent that traps copper ions generated in a semiconductor package. For example, in Patent Document 1, a thermoplastic resin having an epoxy group and not having a carboxyl group and a heterocyclic compound containing a tertiary nitrogen atom as a ring atom are formed, and a complex is formed with a cation. And an organic-based complex-forming compound for producing an adhesive sheet for manufacturing a semiconductor device.

JP, 2013-026566, A

However, the conventional adhesives are not sufficient in terms of suppressing defects caused by the movement of copper ions in the adhesive, and there is still room for improvement.

Therefore, the main object of the present invention is to provide a film-like adhesive capable of sufficiently suppressing the problems associated with the movement of copper ions in the adhesive.

As a result of intensive studies by the present inventors, by using an inorganic filler which has been surface-treated with a specific silane coupling agent, it is possible to sufficiently suppress the problems associated with the movement of copper ions in the adhesive. This has led to the completion of the present invention.

One aspect of the present invention is a film adhesive for adhering a semiconductor element and a supporting member mounting a semiconductor element, wherein the film adhesive is a film adhesive, and a thermosetting resin component, An inorganic filler is included, and the inorganic filler is surface-treated with a vinylsilane coupling agent and an alkylsilane coupling agent.

By using an inorganic filler that has been surface-treated with a specific silane coupling agent, it is not always clear why the migration of copper ions in the adhesive can be sufficiently suppressed, but the present inventors have found that the adhesion of the inorganic filler It is because the compatibility with the agent (thermosetting resin component) is improved, and the interface between the inorganic filler and the adhesive (thermosetting resin component) is small or almost eliminated, which makes it difficult for copper ions to move. thinking.

The inorganic filler may be silica.

The thermosetting resin component may include a thermosetting resin, a curing agent, and an acrylic rubber.

The thickness of the film adhesive may be 50 μm or less.

In another aspect, the present invention provides an adhesive sheet, which comprises a base material and the above-mentioned film adhesive provided on one surface of the base material. The substrate may be a dicing tape.

In another aspect, the present invention includes a semiconductor element, a support member on which the semiconductor element is mounted, and an adhesive member that is provided between the semiconductor element and the support member and that adheres the semiconductor element and the support member. Which is a cured product of the above film adhesive. The support member may include a member made of copper.

In another aspect, the present invention provides a method for manufacturing a semiconductor device, which comprises a step of bonding a semiconductor element and a supporting member using the above film adhesive.

In another aspect, the present invention divides into a plurality of individual pieces by adhering the film adhesive of the above-mentioned adhesive sheet to a semiconductor wafer and cutting the semiconductor wafer to which the film adhesive is attached. There is provided a method of manufacturing a semiconductor device, comprising: a step of producing a semiconductor element with a film adhesive, and a step of adhering the semiconductor element with a film adhesive to a support member. The method for manufacturing a semiconductor device may further include a step of heating the semiconductor element with the film adhesive attached to the supporting member using a reflow furnace.

ADVANTAGE OF THE INVENTION According to this invention, the film-shaped adhesive agent which can fully suppress the malfunction accompanying the movement of the copper ion in an adhesive agent is provided. Further, according to the present invention, an adhesive sheet and a semiconductor device using such a film adhesive are provided. Further, according to the present invention, there is provided a method for manufacturing a semiconductor device using a film adhesive or an adhesive sheet.

It is a schematic cross section which shows one Embodiment of a film adhesive. It is a schematic cross section which shows one Embodiment of an adhesive sheet. It is a schematic cross section which shows other one Embodiment of an adhesive sheet. It is a schematic cross section which shows other one Embodiment of an adhesive sheet. It is a schematic cross section which shows other one Embodiment of an adhesive sheet. It is a schematic cross section which shows one Embodiment of a semiconductor device. It is a schematic cross section which shows other one Embodiment of a semiconductor device.

Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including steps and the like) are not essential unless otherwise specified. The sizes of the constituent elements in each figure are conceptual, and the relative size relationships between the constituent elements are not limited to those shown in each figure.

The same applies to the numerical values and ranges thereof in the present specification, and does not limit the present invention. In the present specification, the numerical range indicated by using "to" indicates the range including the numerical values before and after "to" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present specification, the upper limit or the lower limit described in one numerical range may be replaced with the upper limit or the lower limit of the numerical range described in other stages. Good. Further, in the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

In the present specification, (meth)acrylate means acrylate or corresponding methacrylate. The same applies to other similar expressions such as a (meth)acryloyl group and a (meth)acrylic copolymer.

The film adhesive according to one embodiment is a film adhesive for adhering a semiconductor element and a supporting member on which the semiconductor element is mounted, and the film adhesive is a thermosetting resin component and an inorganic filler. And contain. The inorganic filler is surface-treated with a vinylsilane coupling agent and an alkylsilane coupling agent.

The film adhesive can be obtained by forming an adhesive composition containing (A) a thermosetting resin component and (B) an inorganic filler into a film. The film adhesive and the adhesive composition may be capable of undergoing a semi-cured (B stage) state and then a fully cured (C stage) state after a curing treatment.

In one embodiment, the thermosetting resin component (A) may include (A1) thermosetting resin, (A2) curing agent, and (A3) elastomer.

Component (A1): Thermosetting Resin The component (A1) may be an epoxy resin from the viewpoint of adhesiveness. The epoxy resin can be used without particular limitation as long as it has an epoxy group in the molecule. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin. , Stilbene type epoxy resin, triazine skeleton containing epoxy resin, fluorene skeleton containing epoxy resin, triphenolphenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, polyfunctional phenol And diglycidyl ether compounds of polycyclic aromatic compounds such as anthracene and anthracene. These may be used alone or in combination of two or more. Among these, the component (A1) may be a cresol novolac type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol A type epoxy resin from the viewpoint of tackiness and flexibility of the film.

The epoxy equivalent of the epoxy resin is not particularly limited, but may be 90 to 300 g/eq, 110 to 290 g/eq, or 110 to 290 g/eq. When the epoxy equivalent of the epoxy resin is in such a range, the fluidity tends to be ensured while maintaining the bulk strength of the film adhesive.

Component (A2): Hardener The component (A2) may be a phenol resin that can serve as a hardener for an epoxy resin. The phenol resin can be used without particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of the phenol resin include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol and aminophenol, and/or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene, and formaldehyde. A novolak-type phenol resin obtained by condensation or co-condensation with a compound having an aldehyde group under an acidic catalyst, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenols such as phenol, and/or Alternatively, a phenol aralkyl resin synthesized from naphthols and dimethoxyparaxylene or bis(methoxymethyl)biphenyl, a naphthol aralkyl resin, and the like can be given. These may be used alone or in combination of two or more. Among these, the phenol resin may be a phenol aralkyl resin or a naphthol aralkyl resin.

The hydroxyl equivalent of the phenol resin may be 70 g/eq or more or 70 to 300 g/eq. When the hydroxyl equivalent of the phenolic resin is 70 g/eq or more, the storage elastic modulus of the film tends to be further improved, and when it is 300 g/eq or less, it is possible to prevent problems such as foaming and outgassing. ..

From the viewpoint of curability, the ratio of the epoxy equivalent of the epoxy resin to the hydroxyl equivalent of the phenol resin (epoxy equivalent of the epoxy resin/hydroxyl equivalent of the phenol resin) is 0.30/0.70 to 0.70/0.30. , 0.35/0.65-0.65/0.35, 0.40/0.60-0.60/0.40, or 0.45/0.55-0.55/0.45 You can When the equivalent ratio is 0.30/0.70 or more, more sufficient curability tends to be obtained. When the equivalent ratio is 0.70/0.30 or less, it is possible to prevent the viscosity from becoming too high, and it is possible to obtain more sufficient fluidity.

The total content of the component (A1) and the component (A2) is 5 to 50 parts by mass, 10 to 40 parts by mass, or 15 to 30 parts by mass with respect to 100 parts by mass of the total amount of the component (A). You may. When the total content of the component (A1) and the component (A2) is 5 parts by mass or more, the elastic modulus tends to be improved by crosslinking. When the total content of the component (A1) and the component (A2) is 50 parts by mass or less, the film handleability tends to be maintained.

Component (A3): Elastomer The component (A3) may be an acrylic rubber having a structural unit derived from a (meth)acrylic acid ester as a main component. The content of the structural unit derived from the (meth)acrylic acid ester in the component (A3) may be, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more based on the total amount of the structural unit. The acrylic rubber may contain a structural unit derived from a (meth)acrylic acid ester having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, and a carboxyl group.

Since the acrylic rubber can further suppress the movement of copper ions in the adhesive and is more excellent in embedding property, the acrylic rubber may not contain a constitutional unit derived from acrylonitrile.

In the infrared absorption spectrum of the acrylic rubber, when the height of the P _CO absorption peak derived from stretching vibration of the carbonyl _group, the height of the peak derived from stretching vibration of the nitrile group was P _CN, P _CO and P _CN May satisfy the condition of the following formula (1).
_{P CN / P CO <0.070 (} 1)

Here, the carbonyl group is mainly derived from the structural unit (meth)acrylic acid ester, and the nitrile group is mainly derived from the structural unit acrylonitrile. The height of the absorption peak derived from the stretching vibration of the carbonyl group (P _CO ) and the height of the peak derived from the stretching vibration of the nitrile group (P _CN ) mean those defined in the examples.

A small P _CN /P _CO means that the acrylic rubber has a small number of structural units derived from acrylonitrile. Therefore, an acrylic rubber that does not contain a structural unit derived from acrylonitrile can theoretically satisfy the condition of the formula (1).

P _CN / _{P CO} is less than 0.070, 0.065, 0.060 or less, 0.055 or less, 0.050 or less, 0.040 or less, 0.030 or less, 0.020 or less, or It may be 0.010 or less. When P _CN /P _CO is less than 0.070, it may be possible to sufficiently suppress the movement (permeation) of copper ions in the adhesive. Further, it is possible as the value of P _{CN /} P _CO decreases, more sufficiently suppressed migration of copper ions in the adhesive (transparent). Also, as the value of P _{CN /} P _CO is reduced, to lower the cohesive force of the acrylic rubber tends to be buried resistance more excellent.

The glass transition temperature (Tg) of the component (A3) may be -50 to 50°C or -30 to 30°C. When the Tg of the component (A3) is −50° C. or higher, the flexibility of the adhesive tends to be prevented from becoming too high. As a result, the film adhesive can be easily cut during wafer dicing, and burrs can be prevented from occurring. When the Tg of the component (A3) is 50° C. or lower, the flexibility of the adhesive tends to be suppressed from decreasing. This tends to make it easier to fill voids when the film adhesive is attached to the wafer. Further, it becomes possible to prevent chipping during dicing due to a decrease in the adhesiveness of the wafer. Here, the glass transition temperature (Tg) means a value measured by using a DSC (Thermal Differential Scanning Calorimeter) (for example, Rigaku Co., Ltd., Thermo Plus 2).

The weight average molecular weight (Mw) of the component (A3) may be 100,000 to 3,000,000 or 200,000 to 2,000,000. When the Mw of the component (A3) is in such a range, the film formability, strength in film form, flexibility, tackiness and the like can be appropriately controlled, and the reflowability is excellent and the embedding property is improved. can do. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

Examples of commercially available acrylic rubber as the component (A3) include SG-P3, SG-80H, and HTR-860P-3CSP (all manufactured by Nagase ChemteX Corporation). Examples of commercially available acrylic rubbers that do not contain a structural unit derived from acrylonitrile include KH-CT-865 (manufactured by Hitachi Chemical Co., Ltd.).

The content of the component (A3) may be 50 to 95 parts by mass, 60 to 90 parts by mass, or 70 to 85 parts by mass based on 100 parts by mass of the total amount of the component (A). When the content of the component (A3) is in such a range, the movement (permeation) of copper ions in the adhesive tends to be more sufficiently suppressed.

In another embodiment, the thermosetting resin component (A) is an elastomer having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, and a carboxyl group, and a curing agent capable of reacting with the crosslinkable functional group. , May be included. Examples of the combination of the elastomer having a crosslinkable functional group and the curing agent capable of reacting with the crosslinkable functional group include a combination of an acrylic rubber having an epoxy group and a phenol resin.

Component (B): Inorganic filler As the component (B), for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, Examples thereof include aluminum borate whiskers, boron nitride, and silica. These may be used alone or in combination of two or more. Among these, the component (B) may be silica from the viewpoint of adjusting the melt viscosity. The shape of the component (B) is not particularly limited, but may be spherical.

The component (B) is surface-treated with a vinylsilane coupling agent and an alkylsilane coupling agent. Examples of the vinylsilane coupling agent include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of the alkylsilane coupling agent include, for example, methyltrimethoxysilane, methyltriethoxysilane, methylmethoxysilane, dimethyldichlorosilane, n-propyltrimethoxysilane, n-propylmethyldimethoxysilane, n-propyltriethoxysilane, n. -Butyltriethoxysilane, pentyltrichlorosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane and the like. The surface treatment may be carried out by treating the component (B) with one of the vinylsilane coupling agent and the alkylsilane coupling agent, and then treating the other with the remaining component. It may be treated with a mixture of alkylsilane coupling agents.

From the viewpoint of fluidity, the average particle size of the component (B) may be 0.01 to 1 μm, 0.01 to 0.5 μm, and 0.03 to 0.1 μm. Here, the average particle diameter means a value obtained by converting from the BET specific surface area.

The content of the component (B) is 0.1 to 50 parts by mass, 0.1 to 30 parts by mass, or 0.1 to 20 parts by mass based on 100 parts by mass of the total amount of the component (A). Good. When the content of the component (B) is in such a range, the contact area between the inorganic filler and the adhesive (thermosetting resin component) decreases, and the movement of copper ions tends to be suppressed.

The film adhesive (adhesive composition) may further contain (C) a coupling agent, (D) a curing accelerator and the like.

Component (C): Coupling Agent The component (C) may be a silane coupling agent. Examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. Be done. These may be used alone or in combination of two or more.

Component (D): Curing Accelerator The component (D) is not particularly limited, and those generally used can be used. Examples of the component (D) include imidazoles and their derivatives, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. Among these, the component (D) may be an imidazole or a derivative thereof from the viewpoint of reactivity.

Examples of the imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole and the like. These may be used alone or in combination of two or more.

The film adhesive (adhesive composition) may further contain other components. Examples of other components include pigments, ion trapping agents, antioxidants, and the like.

Content of (C)component, (D)component, and another component may be 0-30 mass parts with respect to 100 mass parts of total mass of (A) component.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a film adhesive. The film adhesive 1 (adhesive film) shown in FIG. 1 is obtained by molding an adhesive composition into a film. The film adhesive 1 may be in a semi-cured (B stage) state. Such a film adhesive 1 can be formed by applying an adhesive composition to a support film. When the varnish of the adhesive composition (adhesive varnish) is used, the components (A) and (B) and other components that are added as necessary are mixed in a solvent, and the mixed liquid is mixed or kneaded. Thus, the adhesive varnish is prepared, the adhesive varnish is applied to the support film, and the solvent is heated and dried to remove the adhesive to form the film adhesive 1.

The support film is not particularly limited as long as it can withstand the above heat drying, for example, polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, polyether naphthalate film, polymethylpentene film, etc. May be The substrate 2 may be a multilayer film in which two or more kinds are combined, and the surface thereof may be treated with a release agent such as a silicone-based or silica-based release agent. The thickness of the support film may be, for example, 60 to 200 μm or 70 to 170 μm.

Mixing or kneading can be performed by using an ordinary stirrer, a raker, a three-roller, a ball mill, or other dispersing machine, and appropriately combining these.

The solvent used for preparing the adhesive varnish is not limited as long as it can uniformly dissolve, knead or disperse each component, and conventionally known solvents can be used. Examples of such a solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene and xylene. The solvent may be methyl ethyl ketone, cyclohexanone or the like because of its high drying rate and low price.

As a method of applying the adhesive varnish to the base film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. Can be mentioned. The heating and drying conditions are not particularly limited as long as the solvent used is sufficiently volatilized, but heating at 50 to 150° C. for 1 to 30 minutes can be performed.

The thickness of the film adhesive may be 50 μm or less. When the thickness of the film adhesive is 50 μm or less, the distance between the semiconductor element and the supporting member on which the semiconductor element is mounted becomes short, so that defects due to copper ions tend to occur easily. Since the film adhesive according to the present embodiment can sufficiently suppress the movement (permeation) of copper ions in the adhesive, the thickness thereof can be 50 μm or less. The thickness of the film adhesive 1 may be 40 μm or less, 30 μm or less, 20 μm or less, or 15 μm or less. The lower limit of the thickness of the film adhesive 1 is not particularly limited, but may be 1 μm or more, for example.

The copper ion permeation time of the film adhesive 1 in the semi-cured (B stage) state may be 200 minutes or longer, 210 minutes or longer, 220 minutes or longer, or 230 minutes or longer. When the copper ion permeation time is 200 minutes or more, it is expected that even if a defect such as insufficient curing occurs during manufacturing of the semiconductor device, a defect due to the copper ion is less likely to occur.

The copper ion permeation time of the film adhesive 1 in the completely cured (C stage) state may be 150 minutes or longer, 200 minutes or longer, 250 minutes or longer, 300 minutes or longer, 350 minutes or longer, 400 minutes or longer, or 450 minutes. It may be more than a minute. Problems due to copper ions tend to occur during high-temperature processing such as reflow process. Therefore, it is predicted that a defect due to copper ions will be less likely to occur when the completely cured (C stage) state is 150 minutes or more.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the adhesive sheet. The adhesive sheet 100 shown in FIG. 2 includes a base material 2 and a film adhesive 1 provided on the base material 2. FIG. 3 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. The adhesive sheet 110 shown in FIG. 3 includes a substrate 2, a film adhesive 1 provided on the substrate 2, and a cover film provided on the surface of the film adhesive 1 opposite to the substrate 2. 3 and.

The substrate 2 is not particularly limited, but may be a substrate film. The base film may be similar to the support film described above.

The cover film 3 is used to prevent damage or contamination of the film adhesive, and may be, for example, a polyethylene film, a polypropylene film, a surface release agent-treated film, or the like. The cover film 3 may have a thickness of, for example, 15 to 200 μm or 70 to 170 μm.

The adhesive sheets 100 and 110 can be formed by applying an adhesive composition to a base film, similarly to the method of forming a film adhesive described above. The method of applying the adhesive composition to the substrate 2 may be the same as the method of applying the adhesive composition described above to the support film.

The adhesive sheet 110 can be obtained by further laminating the cover film 3 on the film adhesive 1.

The adhesive sheets 100 and 110 may be formed using a film-like adhesive agent prepared in advance. In this case, the adhesive sheet 100 can be formed by laminating under a predetermined condition (for example, room temperature (20° C.) or heated state) using a roll laminator, a vacuum laminator, or the like. Since the adhesive sheet 100 can be continuously manufactured and is excellent in efficiency, it may be formed using a roll laminator in a heated state.

Another embodiment of the adhesive sheet is a dicing/die bonding integrated adhesive sheet in which the substrate 2 is a dicing tape. When the dicing/die-bonding integrated adhesive sheet is used, the process of laminating on the semiconductor wafer is performed once, so that the work efficiency can be improved.

Examples of the dicing tape include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. The dicing tape may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment, if necessary. The dicing tape may have adhesiveness. Such a dicing tape may be one in which the above-mentioned plastic film is provided with adhesiveness, or one in which the above-mentioned plastic film is provided with an adhesive layer. The pressure-sensitive adhesive layer may be either a pressure-sensitive type or a radiation-curable type, has a sufficient adhesive force so that the semiconductor element does not scatter during dicing, and does not damage the semiconductor element in the subsequent semiconductor element pickup step. There is no particular limitation as long as it has a low adhesive force, and conventionally known ones can be used.

The thickness of the dicing tape may be 60 to 150 μm or 70 to 130 μm from the viewpoint of economy and handleability of the film.

Examples of such a dicing/die-bonding integrated adhesive sheet include those having the configuration shown in FIG. 4 and those having the configuration shown in FIG. FIG. 4 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. FIG. 5 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. The adhesive sheet 120 shown in FIG. 4 includes the dicing tape 7, the adhesive layer 6, and the film adhesive 1 in this order. The adhesive sheet 130 shown in FIG. 5 includes the dicing tape 7 and the film adhesive 1 provided on the dicing tape 7.

The adhesive sheet 120 can be obtained by, for example, providing the pressure-sensitive adhesive layer 6 on the dicing tape 7 and further laminating the film-shaped adhesive 1 on the pressure-sensitive adhesive layer 6. The adhesive sheet 130 can be obtained, for example, by bonding the dicing tape 7 and the film adhesive 1 together.

The film adhesive and the adhesive sheet may be used for manufacturing a semiconductor device, and the film adhesive and the dicing tape are applied to a semiconductor wafer or a semiconductor element (semiconductor chip) that has already been cut into small pieces at 0° C. After sticking at 90° C., a semiconductor element with a film adhesive is obtained by cutting with a rotary blade, laser or stretching, and then the semiconductor element with the film adhesive is applied to an organic substrate, a lead frame, or another semiconductor element. It may be one used for manufacturing a semiconductor device including a step of adhering on.

Examples of the semiconductor wafer include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

The film adhesive and the adhesive sheet include semiconductor elements such as IC and LSI, lead frames such as 42 alloy lead frame and copper lead frame; plastic films such as polyimide resin and epoxy resin; It can be used as a die bonding adhesive for bonding a resin impregnated and cured with an epoxy resin or the like; a semiconductor mounting support member such as ceramics such as alumina or the like.

The film adhesive and the adhesive sheet are also suitably used as an adhesive for adhering semiconductor elements to each other in a Stacked-PKG having a structure in which a plurality of semiconductor elements are stacked. In this case, one semiconductor element serves as a support member on which the semiconductor element is mounted.

The film adhesive and the adhesive sheet are, for example, a protective sheet for protecting the back surface of the semiconductor element of the flip-chip type semiconductor device, and a material for sealing between the surface of the semiconductor element of the flip-chip type semiconductor device and the adherend. It can also be used as a sealing sheet or the like.

A semiconductor device manufactured using a film adhesive will be specifically described with reference to the drawings. In recent years, semiconductor devices having various structures have been proposed, and the application of the film adhesive according to the present embodiment is not limited to the semiconductor device having the structure described below.

FIG. 6 is a schematic cross-sectional view showing an embodiment of a semiconductor device. A semiconductor device 200 shown in FIG. 6 is provided between the semiconductor element 9, a support member 10 on which the semiconductor element 9 is mounted, and the semiconductor element 9 and the support member 10, and an adhesive member that bonds the semiconductor element 9 and the support member 10 together. (Cured product 1c of film adhesive). A connection terminal (not shown) of the semiconductor element 9 is electrically connected to an external connection terminal (not shown) via a wire 11 and sealed by a sealing material 12.

FIG. 7 is a schematic cross-sectional view showing another embodiment of the semiconductor device. In the semiconductor device 210 shown in FIG. 7, the first-stage semiconductor element 9a is adhered to the support member 10 on which the terminals 13 are formed by an adhesive member (cured material 1c of film adhesive), and the first-stage semiconductor element 9a. The semiconductor element 9b in the second stage is further adhered to the top by an adhesive member (cured product 1c of film adhesive). The connection terminals (not shown) of the semiconductor element 9 a in the first stage and the semiconductor element 9 b in the second stage are electrically connected to the external connection terminals via the wires 11 and sealed by the sealing material 12. As described above, the film adhesive according to the present embodiment can be suitably used for a semiconductor device having a structure in which a plurality of semiconductor elements are stacked.

The semiconductor device (semiconductor package) shown in FIGS. 6 and 7 has, for example, a film-like adhesive interposed between a semiconductor element and a support member or between semiconductor elements, and they are heated and pressure-bonded to each other. Are bonded, and then, if necessary, a wire bonding process, a sealing process with a sealing material, a heating and melting process including reflow with solder, and the like. The heating temperature in the thermocompression bonding step is usually 20 to 250° C., the load is usually 0.1 to 200 N, and the heating time is usually 0.1 to 300 seconds.

As a method of interposing the film adhesive between the semiconductor element and the supporting member or between the semiconductor element and the semiconductor element, as described above, after the film-shaped adhesive-attached semiconductor element is prepared in advance, the supporting member or It may be a method of attaching to a semiconductor element.

The support member may include a member made of copper. In the semiconductor device according to the present embodiment, since the semiconductor element and the supporting member are bonded by the cured product 1c of the film adhesive, a member made of copper is used as a constituent member of the semiconductor device. However, it is possible to reduce the influence of copper ions generated from the member, and it is possible to sufficiently suppress the occurrence of electrical defects due to copper ions.

Here, as the member made of copper, for example, a lead frame, a wiring, a wire, a heat dissipating material, etc. can be cited, but it is possible to reduce the influence of copper ions even when copper is used for any member. Is.

Next, an embodiment of a method for manufacturing a semiconductor device using the dicing/die-bonding integrated adhesive sheet shown in FIG. 4 will be described. The method of manufacturing a semiconductor device using the dicing/die-bonding integrated adhesive sheet is not limited to the method of manufacturing a semiconductor device described below.

First, a semiconductor wafer is pressure-bonded to the film-like adhesive 1 in the adhesive sheet 120 (adhesive sheet with integrated dicing and die bonding), and this is adhesively held and fixed (mounting step). This step may be performed while pressing with a pressing means such as a pressure roll.

Next, the semiconductor wafer is diced. As a result, the semiconductor wafer is cut into a predetermined size to manufacture a plurality of individual semiconductor elements (semiconductor chips) with a film-like adhesive. The dicing can be performed, for example, from the circuit surface side of the semiconductor wafer according to a conventional method. Further, in this step, for example, a cutting method called full-cut in which even dicing tape is cut, a method of making a half-cut in a semiconductor wafer and cutting by cooling and pulling, a cutting method by a laser, and the like can be adopted. The dicing device used in this step is not particularly limited, and a conventionally known device can be used.

A semiconductor element is picked up in order to peel off the semiconductor element that is adhesively fixed to the dicing/die-bonding integrated adhesive sheet. The pickup method is not particularly limited, and various conventionally known methods can be adopted. For example, a method may be mentioned in which individual semiconductor elements are pushed up from the side of the dicing/die-bonding integrated adhesive sheet with a needle, and the pushed up semiconductor elements are picked up by a pickup device.

Here, when the pressure-sensitive adhesive layer is a radiation (for example, ultraviolet ray) curable type, the pickup is performed after irradiating the pressure-sensitive adhesive layer with radiation. As a result, the adhesive strength of the pressure-sensitive adhesive layer to the film adhesive is reduced, and the semiconductor element can be easily peeled off. As a result, the pickup can be performed without damaging the semiconductor element.

Next, the semiconductor element with a film adhesive formed by dicing is adhered to a support member for mounting the semiconductor element via the film adhesive. Bonding may be done by crimping. The conditions for die bonding are not particularly limited, and can be set appropriately as needed. Specifically, for example, the die bonding temperature may be 80 to 160° C., the bonding load may be 5 to 15 N, and the bonding time may be 1 to 10 seconds.

You may provide the process of thermosetting a film adhesive as needed. By thermosetting the film-like adhesive that adheres the support member and the semiconductor element in the adhering step, it becomes possible to more firmly adhere and fix. When heat curing is performed, pressure may be applied simultaneously to cure. The heating temperature in this step can be appropriately changed depending on the constituents of the film adhesive. The heating temperature may be, for example, 60 to 200°C. The temperature or pressure may be changed stepwise.

Next, a wire bonding step of electrically connecting the tip of the terminal portion (inner lead) of the support member and the electrode pad on the semiconductor element with a bonding wire is performed. As the bonding wire, for example, a gold wire, an aluminum wire, a copper wire or the like is used. The temperature for wire bonding may be in the range of 80 to 250°C or 80 to 220°C. The heating time may be several seconds to several minutes. The wire connection may be performed by using the vibration energy of ultrasonic waves and the pressure bonding energy of applied pressure in a state of being heated within the above temperature range.

Next, a sealing step of sealing the semiconductor element with a sealing resin is performed. This step is performed to protect the semiconductor element or the bonding wire mounted on the support member. This step is performed by molding the resin for sealing with a mold. The sealing resin may be, for example, an epoxy resin. The substrate and the residue are embedded by the heat and pressure at the time of sealing, and it is possible to prevent peeling due to bubbles at the adhesive interface.

Next, in the post-curing step, the sealing resin that is insufficiently cured in the sealing step is completely cured. Even if the film adhesive is not heat-cured in the sealing step, the film adhesive is heat-cured together with the curing of the sealing resin in this step so that the adhesive fixation can be achieved. The heating temperature in this step can be appropriately set depending on the type of sealing resin, and may be, for example, in the range of 165 to 185° C., and the heating time may be about 0.5 to 8 hours.

Next, the semiconductor element with the film adhesive attached to the support member is heated using a reflow oven. In this step, a resin-sealed semiconductor device may be surface-mounted on the support member. Examples of the surface mounting method include reflow soldering in which solder is supplied in advance on a printed wiring board and then heated and melted by hot air or the like for soldering. Examples of the heating method include hot air reflow and infrared reflow. Further, the heating method may be a method of heating the entire body or a method of heating a local portion. The heating temperature may be, for example, in the range of 240 to 280°C.

When the semiconductor elements are laminated in multiple layers, heat history in the wire bonding step and the like increases, and the influence of air bubbles existing at the interface between the film adhesive and the semiconductor element on peeling can be significant. However, the film adhesive according to the present embodiment tends to have lower cohesive force and improved embedding property by using a specific acrylic rubber. Therefore, it is difficult for air bubbles to be included in the semiconductor device, the air bubbles can be easily diffused in the sealing step, and peeling due to the air bubbles at the adhesive interface can be prevented.

The present invention will be specifically described below based on examples, but the present invention is not limited thereto.

[Preparation of film adhesive]
(Example 1 and Comparative Examples 1 and 2)
<Preparation of adhesive varnish>
With the product names and composition ratios (unit: parts by mass) shown in Table 1, (A1) an epoxy resin as a thermosetting resin, (A2) a phenol resin as a curing agent, and (B) a composition containing an inorganic filler, and cyclohexanone Was added and mixed with stirring. To this, acrylic rubber (A3) shown in Table 1 as an elastomer was added and stirred, and then (C) a coupling agent and (D) a curing accelerator shown in Table 1 were added until each component became uniform. Stir to prepare an adhesive varnish. In addition, the numerical value of the (A3) component and the (B) component shown in Table 1 means the mass part of solid content.

(A) Thermosetting resin component (A1) Thermosetting resin (A1-1) YDCN-700-10 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., o-cresol novolac type epoxy resin, epoxy equivalent: 209 g/eq. )
(A2) Curing agent (A2-1) HE-100C-30 (trade name, manufactured by Air Water Co., phenylaralkyl type phenol resin, hydroxyl group equivalent: 174 g/eq, softening point 77° C.)
(A3) Elastomer (A3-1) SG-P3 improved product (SG-P3 (trade name, manufactured by Nagase Chemtex Co., Ltd.) in acrylic rubber, excluding constituent units derived from acrylonitrile, weight of acrylic rubber Average molecular weight: 600,000, theoretical Tg of acrylic rubber: 12°C, _PCN / _PCO = 0.001)

(Measurement of IR spectrum)
_P CN _{/ P CO} of (A3-1) was calculated by the following method. First, a solvent was removed from (A3-1), and a transmission IR spectrum was measured by the KBr tablet method, and the vertical axis was the absorbance and the horizontal axis was the wave number (cm ⁻¹ ). FT-IR6300 (manufactured by JASCO Corporation, light source: high-brightness ceramic light source, detector: DLATGS) was used for measuring the IR spectrum.

(Height of absorption peak P _CO due to stretching vibration of carbonyl group)
The highest absorbance peak was a peak point between the two points between 1670 cm ^-1 and 1860 cm ^-1. 1670cm and ^-1 and a linear baseline between the two points between 1860 cm ^-1, and a baseline point that it is the same wave number and the peak point on the base line, the difference in absorbance of the baseline point and the peak point The height (P _CO ) of the absorption peak derived from stretching vibration of the carbonyl group was used.

(Peak height _PCN derived from stretching vibration of nitrile group)
In the same IR spectrum as those seeking P _CO, and the peak point a high peak most absorbance between two points between 2270 cm ^-1 and 2220cm ^-1. 2270cm and ^-1 and a linear baseline between the two points of the 2220Cm ^-1, and a baseline point that it is the same wave number and the peak point on the base line, the difference in absorbance of the baseline point and the peak point The height of the peak derived from stretching vibration of the nitrile group ( _PCN ) was used.

(B) Inorganic filler (B1) YA050C (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion), the silica filler surface-treated with a vinyl silane coupling agent and an alkyl silane coupling agent (average) (Particle size 0.050 μm)
(B2) R972 (trade name, manufactured by Nippon Aerosil Co., Ltd., hydrophobic fumed silica surface-treated with dimethyldichlorosilane (alkylsilane coupling agent), average particle size 0.016 μm)
(B3) Silica filler dispersion liquid (average particle diameter: 0.050 μm) in which the silica filler in YA050C (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion liquid) is surface-treated with an epoxysilane coupling agent.

(C) Coupling agent (C1) A-189 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-mercaptopropyltrimethoxysilane)
(C2) A-1160 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-ureidopropyltriethoxysilane)

(D) Curing accelerator (D1) 2PZ-CN (trade name, 1-cyanoethyl-2-phenylimidazole manufactured by Shikoku Chemicals Co., Ltd.)

<Production of film adhesive>
The produced adhesive varnish was filtered through a 100-mesh filter and vacuum degassed. As a base film, a polyethylene terephthalate (PET) film having a thickness of 38 μm and subjected to a release treatment was prepared, and the adhesive varnish after vacuum defoaming was applied onto the PET film. The applied adhesive varnish was heated and dried in two stages of 90° C. for 5 minutes and 130° C. for 5 minutes to obtain the film adhesives of Example 1 and Comparative Examples 1 and 2 in the B stage state. .. The film adhesive was adjusted to have a thickness of 10 μm depending on the coating amount of the adhesive varnish.

[Measurement of copper ion transmission time]
<Preparation of solution A>
2.0 g of anhydrous copper(II) sulfate was dissolved in 1020 g of distilled water and stirred until copper sulfate was completely dissolved to prepare a copper sulfate aqueous solution having a copper ion concentration of 500 mg/kg in terms of Cu element. The obtained copper sulfate aqueous solution was designated as solution A.

<Preparation of solution B>
1.0 g of anhydrous sodium sulfate was dissolved in 1000 g of distilled water and stirred until the sodium sulfate was completely dissolved. To this, 1000 g of N-methyl-2-pyrrolidone (NMP) was further added and stirred. Then, the mixture was air-cooled to room temperature to obtain a sodium sulfate aqueous solution. The resulting solution was designated as solution B.

<Measurement of copper ion permeation time>
The film adhesives (thickness: 10 μm) of Example 1 and Comparative Examples 1 and 2 produced above were cut out into circles each having a diameter of about 3 cm. Next, two silicon packing sheets having a thickness of 1.5 mm, an outer diameter of about 3 cm and an inner diameter of 1.8 cm were prepared. The film adhesive cut out in a circular shape was sandwiched between two silicon packing sheets, sandwiched between the flange portions of two glass cells having a volume of 50 mL, and fixed with a rubber band.

Next, after injecting 50 g of the liquid A into one glass cell, 50 g of the liquid B was injected into the other glass cell. Mars Carbon (manufactured by Steedler Co., Ltd., φ2 mm/130 mm) was inserted into each cell as a carbon electrode. The liquid A side was used as an anode and the liquid B side was used as a cathode, and the anode was connected to a DC power supply (manufactured by A&D Corporation, DC power supply device AD-9723D). Further, the cathode and the DC power source were connected in series via an ammeter (manufactured by Sanwa Denki Keiki Co., Ltd., Digital multimeter PC-720M). A voltage was applied at an applied voltage of 24.0 V at room temperature, and measurement of the current value was started after the voltage was applied. The measurement was performed until the current value exceeded 15 μA, and the time when the current value reached 10 μA was defined as the copper ion permeation time. The results are shown in Table 1. In this evaluation, it can be said that the longer the permeation time is, the more the copper ion permeation is suppressed.

The film adhesives of Example 1 and Comparative Examples 1 and 2 in the B stage state are further dried by heating at 170° C. for 1 hour, and the film adhesives of Example 1 and Comparative Examples 1 and 2 in the C stage state. Was produced.

Except for changing the film adhesive in the B stage state to the film adhesive in the C stage state, in the same manner as the measurement of the copper ion permeation time when using the film adhesive in the B stage state, The permeation time of copper ions was measured. When the film adhesive in the C stage state was used, the measurement was performed until the current value exceeded 5 μA, and the time when the current value reached 1 μA was defined as the copper ion permeation time. The results are shown in Table 1. In this evaluation, it can be said that the longer the permeation time is, the more the copper ion permeation is suppressed.

As shown in Table 1, the film adhesive of Example 1 was less likely to allow copper ions to permeate than the film adhesives of Comparative Examples 1 and 2.

From the above, it was confirmed that the film-like adhesive of the present invention can sufficiently suppress the problems associated with the movement of copper ions in the adhesive.

DESCRIPTION OF SYMBOLS 1... Film adhesive, 2... Base material, 3... Cover film, 6... Adhesive layer, 7... Dicing tape, 9, 9a, 9b... Semiconductor element, 10... Support member, 11... Wire, 12... Sealing Material, 13... Terminal, 100, 110, 120, 130... Adhesive sheet, 200, 210... Semiconductor device.

Claims (11)

A film-like adhesive for bonding a semiconductor element and a supporting member on which the semiconductor element is mounted,
The film adhesive contains a thermosetting resin component and an inorganic filler,
A film adhesive in which the inorganic filler is surface-treated with a vinylsilane coupling agent and an alkylsilane coupling agent. The film adhesive according to claim 1, wherein the inorganic filler is silica. The film adhesive according to claim 1, wherein the thermosetting resin component contains a thermosetting resin, a curing agent, and an elastomer. The film adhesive according to claim 1, wherein the film adhesive has a thickness of 50 μm or less. Base material,
The film adhesive according to any one of claims 1 to 4, which is provided on one surface of the base material.
An adhesive sheet comprising: The adhesive sheet according to claim 5, wherein the base material is a dicing tape. Semiconductor element,
A supporting member on which the semiconductor element is mounted,
An adhesive member that is provided between the semiconductor element and the support member, and that bonds the semiconductor element and the support member,
Equipped with
A semiconductor device, wherein the adhesive member is a cured product of the film adhesive according to any one of claims 1 to 4. The semiconductor device according to claim 7, wherein the support member includes a member made of copper. A method of manufacturing a semiconductor device, comprising the step of bonding a semiconductor element and a supporting member using the film adhesive according to claim 1. Adhering the film adhesive of the adhesive sheet according to claim 5 or 6 to a semiconductor wafer;
A step of producing a plurality of individual semiconductor elements with a film adhesive by cutting the semiconductor wafer to which the film adhesive is attached,
A step of adhering the semiconductor element with the film adhesive to a support member,
A method for manufacturing a semiconductor device, comprising: The method for manufacturing a semiconductor device according to claim 10, further comprising a step of heating the film-shaped adhesive agent-attached semiconductor element adhered to the support member using a reflow oven.

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