JP2022044992A - Film-like adhesive, adhesive sheet, semiconductor device and production method for the same - Google Patents

Abstract

To provide a film-like adhesive, an adhesive sheet excellent in fragmentation due to cooling expansion, and to provide a semiconductor device and a production method therefor.SOLUTION: There is provided a film-like adhesive for bonding a semiconductor element to a support member on which the element is mounted. The film-like adhesive includes a thermosetting resin, a hardening agent and an elastomer. The elastomer satisfies the following conditions (i) and (ii): (i) a glass transition temperature is 12°C or higher; and (ii) a weight average molecular weight is 800,000 or less.SELECTED DRAWING: Figure 1

Description

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

In recent years, stacked MCPs (Multi Chip Packages) in which semiconductor elements (semiconductor chips) are stacked in multiple stages have become widespread, and are mounted as memory semiconductor packages for mobile phones and portable audio devices. In addition, with the increasing number of functions of mobile phones and the like, the speed, density, and integration of semiconductor packages are being promoted.

Currently, as a method for manufacturing a semiconductor device, a film-like adhesive and a dicing tape are attached to the back surface of a semiconductor wafer, and then a part of the semiconductor wafer, the film-like adhesive, and the dicing tape is cut in a dicing step on the back surface of the semiconductor wafer. The pasting method is generally used. In such a method, it is necessary to cut the film-like adhesive at the same time when dicing the semiconductor wafer, but in a general dicing method using a diamond blade, the semiconductor wafer and the film-like adhesive are cut at the same time. Therefore, it is necessary to slow down the cutting speed, which may lead to an increase in cost.

On the other hand, as a method for classifying a semiconductor wafer, a step of easily classifying the semiconductor wafer, such as a method of irradiating the inside of the semiconductor wafer on the planned cutting line with a laser beam to form a modified region, is performed, and then the outer peripheral portion is expanded. In recent years, a method for cutting a semiconductor wafer has been proposed (for example, Patent Document 1). This method is called stealth dicing. Stealth dicing has the effect of reducing defects such as chipping, especially when the thickness of the semiconductor wafer is thin, and can be expected to have an effect of improving the yield.

JP-A-2002-192370

However, since the film-like adhesive is flexible and easily stretchable, it tends to be difficult to be separated by the expansion of the dicing tape. In order to improve the splittability of the film-like adhesive by expanding (particularly, cooling expanding at a low temperature (for example, in the range of -15 ° C to 0 ° C)), it is necessary to increase the expanding amount of the dicing tape. By increasing the amount of expansion, the amount of deflection of the dicing tape also increases, which may adversely affect the subsequent transport process and the like.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a film-like adhesive having excellent splittability by cooling expand.

One aspect of the present invention provides a film-like adhesive for adhering a semiconductor element and a support member on which the semiconductor element is mounted. The film-like adhesive contains a thermosetting resin, a curing agent, and an elastomer. The elastomer includes an elastomer that satisfies the following condition (i) and the following condition (ii). Such a film-like adhesive can be excellent in fragmentability due to cooling expand.
Condition (i): The glass transition temperature is 12 ° C. or higher.
Condition (ii): The weight average molecular weight is 800,000 or less.

According to the studies by the present inventors, it has been found that the flexibility of the film-shaped adhesive tends to be suppressed by using a specific elastomer in the film-shaped adhesive. Therefore, the present inventors suppress an excessive increase in the flexibility of the film-like adhesive by using such a specific elastomer, and as a result, improve the fragmentability of the film-like adhesive in the cooling expand. I think I can do it.

The film-like adhesive is prepared by preparing a sample having a cross-sectional area A (mm ² ) from the film-like adhesive and by a cutting test under low temperature conditions in the range of -15 ° C to 0 ° C. mm), the step of obtaining the breaking strength P (N), and the breaking elongation L (mm), the step of obtaining the breaking coefficient m represented by the following formula (1), and the breaking resistance represented by the following formula (2). In the fragmentability evaluation method carried out under the following conditions including the step of obtaining R (N / mm ² ), the split coefficient m is more than 0 and 70 or less, and the split resistance R is 0 N / mm ² more than 40 N. It may be a film-like adhesive having a size of / mm ² or less.
m = W / [1000 × (P × L)] (1)
R = P / A (2)
<Conditions>
Sample width: 5 mm
Sample length: 23 mm
Relative velocity between the indentation jig and the sample: 10 mm / min

The film-like adhesive may further contain an inorganic filler.

Another aspect of the present invention provides an adhesive sheet comprising a substrate and the film-like adhesive provided on one surface of the substrate.

Another aspect of the present invention includes a semiconductor element, a support member on which the semiconductor element is mounted, and an adhesive member provided between the semiconductor element and the support member to bond the semiconductor element and the support member, and the adhesive member. Provides a semiconductor device, which is a cured product of the film-like adhesive.

Another aspect of the present invention provides a method for manufacturing a semiconductor device, comprising a step of adhering a semiconductor element and a support member using the film-like adhesive.

Another aspect of the present invention was made into a plurality of pieces by a step of attaching the film-like adhesive of the adhesive sheet to the semiconductor wafer and cutting the semiconductor wafer to which the film-like adhesive was attached. Provided is a method for manufacturing a semiconductor device, comprising a step of manufacturing a semiconductor element with a film-shaped adhesive and a step of adhering the semiconductor element with a film-shaped adhesive to a support member.

According to the present invention, there is provided a film-like adhesive having excellent splittability due to cooling expand. Further, according to the present invention, an adhesive sheet and a semiconductor device using such a film-like adhesive are provided. Further, according to the present invention, there is provided a method for manufacturing a semiconductor device using a film-like adhesive or an adhesive sheet.

It is a schematic cross-sectional view which shows one Embodiment of a film-like adhesive. It is a perspective view which shows typically the sample in the state fixed to the jig. It is sectional drawing which shows typically the state which the load is applied to the sample by a push-in jig. It is a graph which shows an example of the result of the split test schematically. It is a schematic cross-sectional view which shows one Embodiment of an adhesive sheet. It is a schematic cross-sectional view which shows the other embodiment of the adhesive sheet. It is a schematic cross-sectional view which shows the other embodiment of the adhesive sheet. It is a schematic cross-sectional view which shows one Embodiment of a semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device.

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

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

As used herein, (meth) acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth) acryloyl group and (meth) acrylic copolymer.

The film-like adhesive according to one embodiment is for adhering a semiconductor element and a support member on which the semiconductor element is mounted. The film-like adhesive includes a thermosetting resin (hereinafter, may be referred to as "(A) component"), a curing agent (hereinafter, may be referred to as "(B) component"), and an elastomer (hereinafter, may be referred to as "component"). It may be referred to as "(C) component"). The film-like adhesive may further contain an inorganic filler (hereinafter, may be referred to as "component (D)"). The film-like adhesive further includes a coupling agent (hereinafter, may be referred to as "(E) component"), a curing accelerator (hereinafter, may be referred to as "(F) component"), and other components. It may be contained.

The film-like adhesive includes (A) component, (B) component, (C) component, and other components ((D) component, (E) component, (F) component, and others added as needed. It can be obtained by molding an adhesive composition containing (such as the components of) into a film. The film-like adhesive (adhesive composition) may be in a semi-cured (B stage) state and may be in a completely cured (C stage) state after the curing treatment.

Component (A): Thermosetting resin The component (A) may be an epoxy resin from the viewpoint of adhesiveness. 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 novolak type epoxy resin, bisphenol A novolak type epoxy resin, and bisphenol F novolak type epoxy resin. , Stilben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, polyfunctional phenols, polycyclic fragrance such as anthracene Examples thereof include diglycidyl ether compounds of the family. These may be used individually by 1 type or in combination of 2 or more type. Among these, the epoxy resin may be a cresol novolac type epoxy resin.

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.

Component (B): Curing agent The component (B) is a component that acts as a curing agent for the component (A). When the component (A) is an epoxy resin, the component (B) may be a phenol resin that can be a curing agent for the 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 and the like. Phenols such as novolak type phenol resin, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenol and / Alternatively, examples thereof include phenol aralkyl resin synthesized from naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl, naphthol aralkyl resin, biphenyl aralkyl type phenol resin, phenyl aralkyl type phenol resin and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, the phenol resin may be a phenylaralkyl type phenol resin.

The hydroxyl group equivalent of the phenol resin may be 70 g / eq or more or 70 to 300 g / eq. When the hydroxyl group equivalent of the phenol 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 due to the generation of foaming, outgas and the like. ..

When the component (A) is an epoxy resin and the component (B) is a phenol resin, 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 From the viewpoint of curability, 0.30 / 0.70 to 0.70 / 0.30, 0.35 / 0.65 to 0.65 / 0.35, 0.40 / 0.60 to 0.60 / It may be 0.40, or 0.45 / 0.55 to 0.55 / 0.45. When the equivalent amount ratio is 0.30 / 0.70 or more, more sufficient curability tends to be obtained. When the equivalent 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 (A) and the component (B) is 5 to 50 parts by mass and 10 to 40 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B) and the component (C). It may be a part, or 15 to 30 parts by mass. When the total content of the component (A) and the component (B) is 5 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C), the elastic modulus is increased by crosslinking. Tends to improve. When the total content of the component (A) and the component (B) is 50 parts by mass or less with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C), it depends on the film handleability. It tends to be excellent.

Component (C): Elastomer Examples of the component (C) include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, butadiene resin; and modified products of these resins. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (C) is derived from (meth) acrylic acid ester because it has few ionic impurities and is excellent in heat resistance, it is easy to secure connection reliability of a semiconductor device, and it is excellent in fluidity. It may be an acrylic resin (acrylic rubber) having a constituent unit as a main component. The content of the constituent unit derived from the (meth) acrylic acid ester in the component (C) 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 constituent units. The acrylic resin (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, or a carboxyl group.

Among these, the component (C) includes an elastomer satisfying the condition (i) and the condition (ii) (hereinafter, may be referred to as "component (C1)").
Condition (i): The glass transition temperature is 12 ° C. or higher.
Condition (ii): The weight average molecular weight is 800,000 or less.

Regarding the condition (i), the glass transition temperature (Tg) of the component (C1) is 12 ° C. or higher, and may be 15 ° C. or higher, 18 ° C. or higher, or 20 ° C. or higher. When the Tg of the component (C) is 12 ° C. or higher, the adhesive strength of the film-like adhesive can be further improved, and further, it is possible to prevent the film-like adhesive from becoming too flexible. There is a tendency. Therefore, by using such a component (C), the fragmentability of the film-like adhesive in the cooling expand can be improved. The upper limit of Tg of the component (C1) is not particularly limited, but may be, for example, 55 ° C. or lower, 50 ° C. or lower, 45 ° C. or lower, 40 ° C. or lower, 35 ° C. or lower, 30 ° C. or lower, or 25 ° C. or lower. When the Tg of the component (C) is 55 ° C. or lower, the decrease in the flexibility of the film-like adhesive tends to be suppressed. This tends to make it easier to sufficiently embed voids when the film-like adhesive is attached to the semiconductor wafer. In addition, it is possible to prevent chipping during dicing due to a decrease in adhesion to the semiconductor wafer. Here, the glass transition temperature (Tg) means a value measured using a DSC (heat differential scanning calorimeter) (for example, Thermo Plus 2 manufactured by Rigaku Co., Ltd.). The Tg of the component (C) is the type and content of the structural unit constituting the component (C) (when the component (C) is an acrylic resin (acrylic rubber), the structural unit derived from the (meth) acrylic acid ester). Can be adjusted to a desired range by adjusting.

Regarding the condition (ii), the weight average molecular weight (Mw) of the component (C1) is 800,000 or less, and may be 700,000 or less, 600,000 or less, 500,000 or less, 400,000 or less, or 300,000 or less. .. The lower limit of Mw of the component (C1) is not particularly limited, but may be, for example, 10,000 or more, 50,000 or more, or 100,000 or more. When the Mw of the component (C1) is in such a range, the breakability, film formability, film strength, flexibility, tackiness, etc. in the cooling expand of the film can be appropriately controlled, and the reflowability can be improved. It is excellent and can improve the embedding property. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve made of standard polystyrene.

The content of the component (C1) may be 50 to 100% by mass, 70 to 100% by mass, 90 to 100% by mass, or 95 to 100% by mass based on the total amount of the component (C). The content of the component (C1) may be 100% by mass based on the total amount of the component (C).

The component (C) may contain, in addition to the component (C1), an elastomer that does not meet the requirements of the component (C1) (hereinafter, may be referred to as "component (C2)").

The content of the component (C2) may be 0 to 50% by mass, 0 to 30% by mass, 0 to 10% by mass, or 0 to 5% by mass based on the total amount of the component (C). The content of the component (C2) may be 0% by mass based on the total amount of the component (C). That is, the component (C) does not have to contain the component (C2).

The content of the component (C) is 50 to 95 parts by mass, 60 to 90 parts by mass, or 70 to 85 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C). It may be a department. When the content of the component (C) is in such a range, a film having higher elasticity can be obtained, and the die share strength tends to be further increased.

Component (D): Inorganic filler Examples of the component (D) include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, and the like. Examples thereof include aluminum borate whisker, boron nitride, silica and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (D) may be silica from the viewpoint of adjusting the melt viscosity. The shape of the component (D) is not particularly limited, but may be spherical.

The average particle size of the component (D) may be 0.01 to 1 μm, 0.01 to 0.5 μm, 0.01 to 0.3 μm, or 0.01 to 0.1 μm from the viewpoint of fluidity. .. Here, the average particle size means a value obtained by converting from the BET specific surface area.

The content of the component (D) is 0.1 part by mass or more, 1 part by mass or more, and 3 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C). Alternatively, it may be 5 parts by mass or more, 50 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, and 15 parts by mass or less.

Component (E): Coupling agent The component (E) may be a silane coupling agent. Examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and the like. Be done. These may be used individually by 1 type or in combination of 2 or more type.

Component (F): Curing accelerator The component (F) is not particularly limited, and generally used components can be used. Examples of the component (F) include imidazoles and derivatives thereof, organic phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (F) may be imidazoles 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 individually by 1 type or in combination of 2 or more type.

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

The total content of the component (E), the component (F), and other components is 0 to 30 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C). May be.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a film-like adhesive. The film-like adhesive 1 (adhesive film) shown in FIG. 1 is a film-shaped adhesive composition. The film-like adhesive 1 may be in a semi-cured (B stage) state. Such a film-like adhesive 1 can be formed by applying an adhesive composition to a support film. When using an adhesive composition varnish (adhesive varnish), the component (A), the component (B), the component (C), and the component added as necessary are mixed or kneaded in a solvent. A film-like adhesive 1 can be obtained by preparing an adhesive varnish, applying the obtained adhesive varnish to a support film, and removing the solvent by heating and drying.

The support film is not particularly limited as long as it can withstand the above-mentioned heat drying, and for example, polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, polyethylene naphthalate film, polymethylpentene film and the like can be used. It may be there. The base material 2 may be a multilayer film in which two or more types are combined, or may have a surface treated with a mold release agent such as silicone or silica. The thickness of the support film may be, for example, 10 to 200 μm or 20 to 170 μm.

Mixing or kneading can be carried out by using a disperser such as a normal stirrer, a raft machine, a three-roll machine, or a ball mill, and combining these as appropriate.

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, xylene and the like. The solvent may be methyl ethyl ketone or cyclohexanone from the viewpoint of drying speed and price.

As a method of applying the adhesive varnish to the support 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. Be done. The heat-drying is not particularly limited as long as the solvent used is sufficiently volatilized, but can be carried out by heating at 50 to 150 ° C. for 1 to 30 minutes.

The thickness of the film-like adhesive 1 may be 50 μm or less, 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-shaped adhesive 1 is not particularly limited, but may be, for example, 1 μm or more.

The film-like adhesive 1 is a film under a fragmentability evaluation method (for example, in the range of −15 ° C. to 0 ° C.) at which cooling expansion is performed, using the results of a splitting test conducted under the following conditions. In the method for evaluating the breakability of the state adhesive), the film-like adhesive may have a breaking coefficient m of more than 0 and 70 or less and a breaking resistance R of 0 N / mm and more than ² and 40 N / mm ² or less.
<Conditions>
Sample width: 5 mm
Sample length: 23 mm
Relative velocity between the indentation jig and the sample: 10 mm / min

Hereinafter, the cutting test will be described. The fracture test is classified as a bending strength test, and includes a step of pushing the center portion of the sample until the sample breaks with both ends fixed. As shown in FIG. 2, the sample S is subjected to a cutting test in a state of being sandwiched and fixed by a pair of sample fixing jigs 14. The pair of sample fixing jigs 14 are made of, for example, thick paper having sufficient strength, and each has a rectangular opening 14a in the center. A load is applied to the central portion of the sample S in the fixed state by using the pushing jig 15 (see FIG. 3).

The sample S may be any as long as it is obtained by cutting out the film-shaped adhesive to be evaluated, and it is not necessary to prepare a sample by laminating a plurality of adhesive pieces cut out from the film-shaped adhesive. That is, the thickness of the sample S may be the same as the thickness of the film-like adhesive. The width of the sample S (Ws in FIG. 2) is, for example, 1 to 30 mm, and may be 3 to 8 mm. The width may be set appropriately according to the situation of the measuring device. The length of the sample S (Ls in FIG. 2) is, for example, 5 to 50 mm, and may be 10 to 30 mm or 6 to 9 mm. The length of the sample S depends on the size of the opening 14a of the sample fixing jig 14. The shape of the sample fixing jig 14 and the size of the sample S may be other than those described above as long as the cutting test can be performed.

The push jig 15 is made of a columnar member having a conical tip portion 15a. The diameter of the indentation jig 15 (R in FIG. 3) is, for example, 3 to 15 mm, and may be 5 to 10 mm. The angle of the tip portion 15a (θ in FIG. 3) is, for example, 40 to 120 °, and may be 60 to 100 °.

The split test is carried out in a constant temperature bath set to a predetermined temperature. The constant temperature bath may be set to a constant temperature in the range of −15 ° C. to 0 ° C. (assumed cooling expand temperature). As the constant temperature bath, for example, TLF-R3-F-W-PL-S manufactured by Aitec Inc. can be used. An autograph (for example, AZT-CA01 manufactured by A & D Co., Ltd., load cell 50N, compression mode) is used to obtain a breaking work W, a breaking strength P, and a breaking elongation L.

The relative speed between the indentation jig 15 and the sample S is, for example, 1 to 100 mm / min, and may be 5 to 20 mm / min. If this relative velocity is too fast, it tends to be difficult to obtain sufficient data on the splitting process, and if it is too slow, the stress is relaxed and it tends to be difficult to reach splitting. The pushing distance of the pushing jig 15 is, for example, 1 to 50 mm, and may be 5 to 30 mm. If the pushing distance is too short, it tends not to be cut. For the film-like adhesive to be evaluated, it is preferable to prepare a plurality of samples and perform a splitting test a plurality of times to confirm the stability of the test results.

FIG. 4 is a graph showing an example of the result of the cutting test. As shown in FIG. 4, the split work W is an area surrounded when a graph is created with the vertical axis as a load and the horizontal axis as the amount of pushing until the sample S breaks. The breaking strength P is the load when the sample S is broken. The split elongation L is the amount of elongation of the sample S when the sample S is broken. The split elongation L may be calculated using a trigonometric function from the pushing distance when the sample S is broken and the width of the opening 14a of the sample fixing jig 14.

From the values of the breaking work W (N · mm), the breaking strength P (N), and the breaking elongation L (mm) obtained by the breaking test, the breaking coefficient m (dimensionless) from the equations (1) and (2). And the breaking resistance R (N / mm ² ) is obtained.
m = W / [1000 × (P × L)] (1)
R = P / A (2)

According to the study by the present inventors, a film having a breaking coefficient m of more than 0 and 70 or less and a breaking resistance R of 0 N / mm ² and more and 40 N / mm ² or less when the breaking test is carried out under the following conditions. The shape adhesive tends to have excellent breakability when actually cooled and expanded in stealth dicing.
<Conditions>
Sample width: 5 mm
Sample length: 23 mm
Relative velocity between the indentation jig and the sample: 10 mm / min

As described above, the split coefficient m (dimensionless) may be more than 0 and 70 or less, and may be 10 to 60 or 15 to 55. The split coefficient m is a parameter relating to the stretchability of the film-like adhesive under low temperature conditions. When the splitting coefficient m exceeds 70, the splitting property due to the cooling expand tends to be insufficient due to the excessive stretchability of the film-like adhesive. When the split coefficient m is 15 or more, the stress propagation tends to be good. The breaking resistance R may be 0 N / mm ² or more and 40 N / mm ² or less, and may be 0 N / mm ² or more and 35 N / mm ² or less or 1 to 30 N / mm ² . When the breaking resistance R exceeds 40 N / mm ² , the breakability due to the cooling expand tends to be insufficient due to the excessive strength of the film-like adhesive. When the breaking resistance R is 20 N / mm ² or more, there is a tendency that even better splitting property due to the cooling expand can be obtained by good stress propagation in the cooling expand. A film-like adhesive having a breaking coefficient m and a breaking resistance R in the above ranges can be suitably used for stealth dicing. A film-like adhesive having a breaking coefficient m and a breaking resistance R in the above ranges can be applied to a manufacturing process of a semiconductor device in which cooling expansion is carried out.

FIG. 5 is a schematic cross-sectional view showing an embodiment of the adhesive sheet. The adhesive sheet 100 shown in FIG. 5 includes a base material 2 and a film-like adhesive 1 provided on the base material 2. FIG. 6 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. The adhesive sheet 110 shown in FIG. 6 is a cover film provided on a surface opposite to the base material 2, the film-like adhesive 1 provided on the base material 2, and the base material 2 of the film-like adhesive 1. It is equipped with 3.

As the base material 2, the same material as the above-mentioned support film can be used.

The cover film 3 is used to prevent damage or contamination of the film-like adhesive, and may be, for example, a polyethylene film, a polypropylene film, a surface release agent-treated film, or the like. The thickness of the cover film 3 may be, 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 (adhesive varnish) to the base material 2 in the same manner as in the above-mentioned method for forming a film-like adhesive. The method of applying the adhesive composition to the base material 2 may be the same as the method of applying the above-mentioned adhesive composition (adhesive varnish) to the support film.

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

The adhesive sheets 100 and 110 can be formed by using a film-like adhesive prepared in advance. In this case, the adhesive sheet 100 can be formed by laminating on the base material 2 under predetermined conditions (for example, at room temperature (20 ° C.) or in a 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 by 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 base material 2 is a dicing tape. FIG. 7 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. The adhesive sheet 120 (dicing / die bonding integrated adhesive sheet) shown in FIG. 7 includes a dicing tape 8 and a film-like adhesive 1 provided on the dicing tape 8. When the dicing / die bonding integrated adhesive sheet is used, the laminating process on the semiconductor wafer is performed once, so that the work efficiency can be improved.

In one embodiment, the dicing tape 8 includes a base film 7 and an adhesive layer 6 provided on the base film 7.

Examples of the base film 7 include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. If necessary, these base films 7 may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment.

The pressure-sensitive adhesive layer 6 is not particularly limited as long as it has a sufficient adhesive strength that the semiconductor element does not scatter during dicing and has a low adhesive strength that does not damage the semiconductor element in the subsequent pickup process of the semiconductor element. , Conventionally known materials in the field of dicing tape can be used. The pressure-sensitive adhesive layer 6 may be either a pressure-sensitive type or a radiation-curable type.

The thickness of the dicing tape 8 (base film 7 and the pressure-sensitive adhesive layer 6) may be 60 to 150 μm or 70 to 130 μm from the viewpoint of economy and handleability of the film.

The adhesive sheet 120 (dicing / die bonding integrated adhesive sheet) can be obtained, for example, by adhering the pressure-sensitive adhesive layer 6 of the dicing tape 8 and the film-like adhesive 1.

The film-like adhesive and the adhesive sheet may be used for manufacturing a semiconductor device, and the film-like adhesive and the dicing tape are applied to a semiconductor wafer or a semiconductor element (semiconductor chip) that has already been fragmented at 0 ° C. After bonding at ~ 90 ° C., a semiconductor device with a film-like adhesive is obtained by splitting with a rotary blade, a laser or stretching, and then the semiconductor device with the film-like adhesive is used as an organic substrate, a lead frame, or another semiconductor. It may be used in the manufacture of a semiconductor device including a step of adhering to an element.

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

The film-like adhesive and adhesive sheet include semiconductor elements such as ICs and LSIs, lead frames such as 42 alloy lead frames and copper lead frames; plastic films such as polyimide resin and epoxy resin; and polyimide resins on a base material such as glass non-woven fabric. Impregnated and cured with a plastic such as an epoxy resin; it can be used as an adhesive for bonding to a support member for mounting a semiconductor such as ceramics such as alumina.

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

The film-like 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 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.

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

FIG. 8 is a schematic cross-sectional view showing an embodiment of a semiconductor device. The semiconductor device 200 shown in FIG. 8 is provided between the semiconductor element 9, the support member 10 on which the semiconductor element 9 is mounted, and the semiconductor element 9 and the support member 10, and is an adhesive member that adheres the semiconductor element 9 and the support member 10. (Cured product 1c of film-like adhesive) is provided. The connection terminal (not shown) of the semiconductor element 9 is electrically connected to the external connection terminal (not shown) via the wire 11 and is sealed by the sealing material 12.

FIG. 9 is a schematic cross-sectional view showing another embodiment of the semiconductor device. In the semiconductor device 210 shown in FIG. 9, the first-stage semiconductor element 9a is adhered to the support member 10 on which the terminal 13 is formed by an adhesive member (cured product 1c of a film-like adhesive), and the first-stage semiconductor element 9a is attached. The second-stage semiconductor element 9b is further adhered to the top by an adhesive member (cured product 1c of a film-like adhesive). The connection terminals (not shown) of the first-stage semiconductor element 9a and the second-stage semiconductor element 9b are electrically connected to the external connection terminal via the wire 11 and sealed by the sealing material 12. As described above, the film-like 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.

In the semiconductor device (semiconductor package) shown in FIGS. 8 and 9, for example, a film-like adhesive is interposed between the semiconductor element and the support member or between the semiconductor element and the semiconductor element, and these are heat-bonded to both of them. Is then adhered, and if necessary, it is obtained through a wire bonding step, a sealing step with a sealing material, a heating and melting step including reflow with solder, and the like. The heating temperature in the heat crimping 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 a film-like adhesive between a semiconductor element and a support member or between a semiconductor element and a semiconductor element, as described above, after manufacturing a semiconductor element with a film-like adhesive in advance, the support member or the support member or It may be a method of attaching to a semiconductor element.

Next, an embodiment of a method for manufacturing a semiconductor device when the dicing / die bonding integrated adhesive sheet shown in FIG. 7 is used will be described. The method for manufacturing a semiconductor device using a dicing / die bonding integrated adhesive sheet is not limited to the method for manufacturing a semiconductor device described below.

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

Next, dicing of the semiconductor wafer is performed. As a result, the semiconductor wafer is cut into a predetermined size to manufacture a plurality of individualized semiconductor elements (semiconductor chips) with a film-like adhesive. 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 a dicing tape is cut, a method in which a half cut is made in a semiconductor wafer and the semiconductor wafer is cooled and pulled to be divided, a cutting method using a laser, and the like can be adopted. The dicing apparatus used in this step is not particularly limited, and conventionally known dicing apparatus can be used.

The semiconductor element is picked up in order to peel off the semiconductor element bonded and 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 in which individual semiconductor elements are pushed up from the dicing / die bonding integrated adhesive sheet side by a needle and the pushed up semiconductor elements are picked up by a pickup device and the like can be mentioned.

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

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

If necessary, a step of thermosetting the film-like adhesive may be provided. By thermosetting the film-like adhesive that adheres the support member and the semiconductor element by the above-mentioned bonding process, more firmly bonding and fixing becomes possible. When performing thermosetting, pressure may be applied at the same time to cure. The heating temperature in this step can be appropriately changed depending on the constituent components of the film-shaped adhesive. The heating temperature may be, for example, 60 to 200 ° C. The temperature or pressure may be changed step by step.

Next, a wire bonding step is performed in which the tip of the terminal portion (inner lead) of the support member and the electrode pad on the semiconductor element are electrically connected by a bonding wire. As the bonding wire, for example, a gold wire, an aluminum wire, a copper wire, or the like is used. The temperature at which wire bonding is performed 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 wiring may be performed by a combination of vibration energy by ultrasonic waves and crimping energy by applied pressurization in a state of being heated within the above temperature range.

Next, a sealing step of sealing the semiconductor element with the 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 a sealing resin with a mold. The sealing resin may be, for example, an epoxy-based 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 air bubbles at the bonding interface.

Next, in the post-curing step, the insufficiently cured sealing resin is completely cured in the sealing step. Even if the film-like adhesive is not heat-cured in the sealing step, the film-like adhesive can be heat-cured together with the curing of the sealing resin to be bonded and fixed in this step. The heating temperature in this step can be appropriately set depending on the type of the 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 a film-like adhesive bonded to the support member is heated using a reflow furnace. In this step, a resin-sealed semiconductor device may be surface-mounted on the support member. Examples of the surface mount method include reflow soldering in which solder is previously supplied onto a printed wiring board and then heated and melted by warm air or the like to perform soldering. Examples of the heating method include hot air reflow and infrared reflow. Further, the heating method may be one that heats the whole or one that heats a local part. The heating temperature may be, for example, in the range of 240 to 280 ° C.

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

[Making a film-like adhesive]
(Examples 1 to 6 and Comparative Example 1)
<Preparation of adhesive varnish>
Cyclohexanone was added to the composition consisting of the component (A), the component (B), and the component (D) with the components and contents (unit: parts by mass) shown in Table 1, and the mixture was stirred and mixed. To this, the component (C) (component (C1) or component (C2)) is added and stirred, and then the components (E) and (F) are further added, and the mixture is stirred until each component becomes uniform and adhered. An agent varnish was prepared. The numerical value of the component (C) shown in Table 1 means the mass part of the solid content.

In addition, each component shown in Table 1 means the following.

(A) Component: Thermosetting resin (A-1) YDCN-700-10 (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, o-cresol novolac type epoxy resin, epoxy equivalent: 209 g / eq)

(B) Ingredient: Hardener (B-1) HE-100C-30 (trade name, manufactured by Air Water Inc., phenylaralkyl-type phenol resin, hydroxyl group equivalent: 174 g / eq, softening point 77 ° C.)

(C) Ingredient: Elastomer (C1) Ingredient: Elastomer (C1-1) acrylic rubber solution (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, manufactured by Nagase ChemteX Corporation) that satisfies the conditions (i) and (ii), acrylic rubber methyl ethyl ketone Acrylic rubber in solution), a solution of acrylic rubber in which a part of the constituent unit of the acrylic rubber is changed, actual measurement Tg of acrylic rubber: 20 ° C., weight average molecular weight of acrylic rubber: 800,000)
(C1-2) Acrylic rubber solution in which a part of the constituent unit of the acrylic rubber is changed in the acrylic rubber in the acrylic rubber solution (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, methyl ethyl ketone solution of acrylic rubber)). , Measured Tg of acrylic rubber: 25 ° C, Weight average molecular weight of acrylic rubber: 800,000)
(C1-3) Acrylic rubber solution in which a part of the constituent unit of the acrylic rubber is changed in the acrylic rubber in the acrylic rubber solution (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, methyl ethyl ketone solution of acrylic rubber)). , Measured Tg of acrylic rubber: 12 ° C, Weight average molecular weight of acrylic rubber: 500,000)
(C1-4) Acrylic rubber solution in which a part of the constituent unit of the acrylic rubber is changed in the acrylic rubber in the acrylic rubber solution (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, methyl ethyl ketone solution of acrylic rubber)). , Measured Tg of acrylic rubber: 20 ° C, Weight average molecular weight of acrylic rubber: 500,000)
(C1-5) Acrylic rubber solution in which a part of the constituent unit of the acrylic rubber is changed in the acrylic rubber in the acrylic rubber solution (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, methyl ethyl ketone solution of acrylic rubber)). , Measured Tg of acrylic rubber: 20 ° C, Weight average molecular weight of acrylic rubber: 200,000)
Component (C2): Acrylic rubber in an elastomer (C2-1) acrylic rubber solution other than the component (C1) (SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, methyl ethyl ketone solution of acrylic rubber)) of the acrylic rubber. Acrylic rubber solution with a part of the structural unit changed, actual measurement Tg of acrylic rubber: 3 ° C, weight average molecular weight of acrylic rubber: 800,000)

(D) Inorganic filler (D-1) R972 (trade name, manufactured by Nippon Aerosil Co., Ltd., silica particles, average particle size: 0.016 μm)

(E) Ingredient: Coupling agent (E-1) A-189 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-mercaptopropyltrimethoxysilane)
(E-2) A-1160 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-ureidopropyltriethoxysilane)

(F) Ingredient: Curing accelerator (F-1) 2PZ-CN (trade name, manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole)

<Making a film-like adhesive>
The prepared adhesive varnish was filtered through a 100 mesh filter and vacuum defoamed. As a base material, a polyethylene terephthalate (PET) film having been subjected to a mold release treatment having a thickness of 38 μm was prepared, and an adhesive varnish after vacuum defoaming was applied onto the PET film. The applied adhesive varnish was heat-dried at 90 ° C. for 5 minutes and then at 130 ° C. for 5 minutes in two steps to obtain film-like adhesives of Examples 1 to 3 and Comparative Example 1 in the B stage state. .. In the film-shaped adhesive, the thickness of the film-shaped adhesive was adjusted to 10 μm depending on the amount of the adhesive varnish applied.

<Evaluation of fragmentability by cooling expand of film-like adhesive>
Adhesive pieces (width 5 mm × length 100 mm) were cut out from the film-like adhesives of Examples 1 to 6 and Comparative Example 1, respectively. The adhesive piece was fixed to a pair of jigs (thick paper), and the part of the adhesive piece protruding from the jig was removed. As a result, a sample to be evaluated (width 5 mm × length 23 mm) was obtained. A split test was carried out in a constant temperature bath (TLF-R3-F-W-PL-S manufactured by Aitec Inc.) set to a predetermined temperature condition. That is, when a split test was carried out using an autograph (manufactured by A & D Co., Ltd., AZT-CA01, load cell 50N) under the conditions of a compression mode, a speed of 10 mm / min, and a pushing distance of 5 mm, when the film-like adhesive broke. The breaking work W, the breaking strength P, and the breaking elongation L were obtained. The breaking coefficient m and the breaking resistance R were calculated by the above equations (1) and (2). A split test was carried out eight or more times for each example and each comparative example. The results are shown in Table 1. The values shown in Table 1 are the average values of the results obtained by the plurality of fracture tests.

In order to confirm that the fragmentability evaluation matches the fragmentability in the cooling expand, a dicing / die bonding integrated film having the film-like adhesives of Examples 1 to 6 and Comparative Example 1 as an adhesive layer was prepared. Then, the fragmentability of the adhesive layer (film-like adhesive) was evaluated under the following conditions.
・ Thickness of silicon wafer: 30 μm
-Chip size that is individualized by stealth dicing: length 10 mm x width 10 mm
・ Temperature of cooling expand: Same temperature as the constant temperature bath of the split test of Examples and Comparative Examples ・ Push-up by the expansion ring: 10 mm
-Evaluation criteria: The silicon wafer after being pushed up by the expanding ring was irradiated with light. Those in which light passes between adjacent chips with adhesive pieces (silicon wafer and adhesive layer are separated) are evaluated as "A", and those in which light does not pass (silicon wafer and adhesive layer). Was not divided) was evaluated as "B". The results are shown in Table 1.

As shown in Table 1, the film-like adhesives of Examples 1 to 6 have a splitting coefficient m of 70 or less, a breaking resistance R of 40 N / mm ² or less, and a splittability evaluation by cooling expand of "A". Met. On the other hand, the film-like adhesive of Comparative Example 1 had a breaking coefficient m of more than 70, a breaking resistance R of more than 40 N / mm ² , and a breaking property evaluation by cooling expand was “B”. .. From these results, it was confirmed that the film-like adhesive of the present invention has excellent breakability by cooling expand.

1 ... film-like adhesive, 2 ... base material, 3 ... cover film, 6 ... adhesive layer, 7 ... base film, 8 ... dicing tape, 9, 9a, 9b ... semiconductor element, 10 ... support member, 11 ... Wire, 12 ... Sealing material, 13 ... Terminal, 14 ... Sample fixing jig, 14a ... Opening, 15 ... Pushing jig, 15a ... Tip, 100, 110, 120 ... Adhesive sheet, 200, 210 ... Semiconductor device, S …sample.

Claims (8)

A film-like adhesive for adhering a semiconductor element and a support member on which the semiconductor element is mounted.
The film-like adhesive contains a thermosetting resin, a curing agent, and an elastomer.
A film-like adhesive comprising an elastomer in which the elastomer satisfies the following condition (i) and the following condition (ii).
Condition (i): The glass transition temperature is 12 ° C. or higher.
Condition (ii): The weight average molecular weight is 800,000 or less. A step of preparing a sample having a cross-sectional area A (mm ² ) from the film-like adhesive, and
A step of obtaining the breaking work W (N · mm), breaking strength P (N), and breaking elongation L (mm) of the sample by a breaking test under a low temperature condition in the range of -15 ° C to 0 ° C.
The process of obtaining the split coefficient m represented by the following equation (1) and
The process of obtaining the breaking resistance R (N / mm ² ) represented by the following equation (2) and
The fragmentability evaluation method carried out under the following conditions, wherein the splitting coefficient m is more than 0 and 70 or less, and the breaking resistance R is 0 N / mm and more than ² and 40 N / mm ² or less. The film-like adhesive described.
m = W / [1000 × (P × L)] (1)
R = P / A (2)
<Conditions>
Sample width: 5 mm
Sample length: 23 mm
Relative velocity between the indentation jig and the sample: 10 mm / min The film-like adhesive according to claim 1 or 2, wherein the film-like adhesive further contains an inorganic filler. With the base material
The film-like adhesive according to any one of claims 1 to 3 provided on one surface of the substrate, and the film-like adhesive.
Equipped with an adhesive sheet. The adhesive sheet according to claim 4, wherein the base material is a dicing tape. With semiconductor devices
A support member on which the semiconductor element is mounted and
An adhesive member provided between the semiconductor element and the support member to bond the semiconductor element and the support member, and an adhesive member.
Equipped with
A semiconductor device in which the adhesive member is a cured product of the film-like adhesive according to any one of claims 1 to 3. A method for manufacturing a semiconductor device, comprising a step of adhering a semiconductor element and a support member using the film-like adhesive according to any one of claims 1 to 3. The step of attaching the film-like adhesive of the adhesive sheet according to claim 4 or 5 to the semiconductor wafer,
A step of manufacturing a plurality of individualized semiconductor devices with a film-like adhesive by cutting the semiconductor wafer to which the film-like adhesive is attached.
The process of adhering the semiconductor element with a film-like adhesive to the support member,
A method for manufacturing a semiconductor device.

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