TWI774916B - Manufacturing method of semiconductor device, film-like adhesive, and adhesive sheet - Google Patents

Abstract

A method of manufacturing a semiconductor device, comprising: a first mounting step of electrically connecting a first semiconductor element to a substrate via a first wire; and placing a single side of a second semiconductor element larger in area than the first semiconductor element a lamination step of attaching a film-like adhesive; and mounting the film-like adhesive by placing the second semiconductor element to which the film-like adhesive is applied so that the film-like adhesive covers the first semiconductor element, thereby attaching the film-like adhesive The first line and the first semiconductor element are embedded in the second mounting step of the film-like adhesive, and the film-like adhesive is measured at a frequency of 79.0Hz and has a shear viscosity of 300Pa at 80°C. s or less, and when the shear viscosity at 80°C is Y, the frequency is X, and the relation between X and Y is approximated to a power and expressed as Y= ^aXb , the coordinates (X) are plotted on a logarithmic graph. , Y) when the slope b of the power approximation curve of X and Y is -0.67 or less.

Description

Manufacturing method of semiconductor device, film adhesive, and adhesive sheet

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

With the multi-functionalization of mobile phones and the like, a stacked multi-chip package (MCP) in which semiconductor elements are stacked in multiple stages to increase the capacity has become popular. In the mounting of semiconductor elements, the widespread use is beneficial to the mounting procedure. The film adhesive is used as an adhesive for die bonding. As an example of a multi-stage build-up package using such a film-like adhesive, a die-embedded package can be mentioned. It is a package in which a semiconductor element is mounted (crimped) on the lowermost layer in a multi-stage laminate package, and a high-flowing film adhesive is mounted (crimped) from above to embed the semiconductor element, and is mounted It is used in memory packages for mobile phones and mobile audio (audio) devices, etc.

One of the important properties required for semiconductor devices such as the stacked MCP is connection reliability. In order to improve connection reliability, film adhesives that consider properties such as heat resistance, moisture resistance, and reflow resistance are being developed. development. As such a film-like adhesive, for example, Patent Document 1 proposes an adhesive sheet containing a resin and a filler and having a thickness of 10 μm to 250 μm, the resin containing a specific high molecular weight component and mainly epoxy resin Thermosetting ingredients of ingredients. In addition, Patent Document 2 proposes an adhesive composition containing an epoxy resin and a phenol Mixtures of resins, and acrylic copolymers.

The connection reliability of the semiconductor device also depends largely on whether the semiconductor element can be mounted without creating voids in the bonding surface. Therefore, attempts are being made to use a film-like adhesive with a high flow rate so that the semiconductor element can be mounted without generating a void, or to use a film-like adhesive with a low elastic modulus so that the generated void can be eliminated by a sealing step of the semiconductor element or the like. agent, etc. For example, Patent Document 3 proposes an adhesive sheet with low viscosity and low adhesive strength.

[Prior Art Literature] [Patent Literature]

Patent Document 1: International Publication No. 2005/103180

Patent Document 2: Japanese Patent Laid-Open No. 2002-220576

Patent Document 3: Japanese Patent Laid-Open No. 2009-120830

In the adhesive films of Patent Document 1 and Patent Document 3, etc., since a wafer (semiconductor element) is embedded at the time of mounting, a large amount of epoxy resin or the like is contained for the purpose of high fluidity. Therefore, thermal hardening is carried out by the heat generated in the manufacturing process of the semiconductor device, and then the film becomes highly elastic, so it may be at high temperature during sealing. The adhesive film does not deform under high pressure conditions, and the voids formed during installation do not disappear eventually. On the other hand, the adhesive film or the like of Patent Document 2 has a low modulus of elasticity, so that voids can be eliminated in the sealing step, but exposure (bleeding) of the resin from the edge of the wafer after mounting increases, which may contaminate the periphery of the wafer. part of the package body. These topics are discussed in more detail below instruction of.

In recent years, attention has been paid to speeding up the operation of wafer-embedded semiconductor devices. Conventionally, a controller chip that controls the operation of a semiconductor device has been placed on the uppermost stage of a stacked semiconductor element. However, in order to speed up the operation, a packaging technology for a semiconductor device in which the controller chip is placed on the lowermost stage is being developed. As one form of this type of packaging, the film-like adhesive used for mounting the second-stage semiconductor element in the multilayered semiconductor element is thicker, and the controller chip is embedded in the film-like adhesive. The package has attracted attention. Film adhesives used for such applications are required to have high fluidity capable of burying the controller chip and wires connected to the controller chip, and the level difference caused by the unevenness of the substrate surface. The adhesive sheet-like high-flow film of Document 2 can solve these problems.

However, the problem here is that when a resin with high flow is used, extravasation (bleeding) of the resin from the wafer edge increases. In particular, in a wafer-embedded type semiconductor device, the film-like adhesive is thickened in order to realize embedding, and the amount of bleeding becomes more significant in order to remove the volume of the embedded wafer. Pads and circuits for connecting wires are formed on the periphery of the chip, and if the amount of seepage is large, there is a fear that the surface of the package including these will be contaminated. Therefore, the film adhesive is required to have high fluidity for embedding controller wafers and wires, and on the other hand, it is required to ensure low fluidity in order to suppress bleeding.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a method of manufacturing a semiconductor device which can have both good wafer embedding properties and low exudation properties. Moreover, the objective of this invention is to provide the film-like adhesive which can be used in the said manufacturing method, and the dicing using the same. Bonded die-integrated adhesive.

In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly studied the adjustment of the physical properties of the film-like adhesive used in the manufacture of semiconductor devices. Furthermore, the inventors of the present invention found that by using a film adhesive whose shear viscosity at a specific frequency is in a specific range and satisfies a specific relationship between shear viscosity and frequency, it is possible to realize both good wafer embedding sex and low exudation.

That is, in order to solve the above-mentioned problems, the present invention provides a method of manufacturing a semiconductor device, comprising: a first mounting step of electrically connecting a first semiconductor element to a substrate via a first wire; and a lamination step of A film-like adhesive is attached to one side of a second semiconductor element having a larger area of the first semiconductor element; and in a second mounting step, the film-like adhesive is placed so as to cover the first semiconductor element. The second semiconductor element with the film-like adhesive is attached, and the film-like adhesive is mounted, whereby the first wire and the first semiconductor element are embedded in the film-like adhesive, and the film The shear viscosity of the adhesive is 300Pa at 80°C measured at a frequency of 79.0Hz. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the relationship between X and Y is approximated to a power and expressed as Y=aXb, the slope ^b of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on a logarithmic graph is -0.67 or less.

According to the method of manufacturing a semiconductor device, 80° C. measured under the condition of a frequency of 79.0 Hz with the film-like adhesive used for mounting (pressure-bonding) the second semiconductor element on the first semiconductor element The shear viscosity at 300 Pa. s or less, the first semiconductor element and the first wire can be embedded with the film-like adhesive while suppressing the generation of voids. In addition, when the slope b obtained from the relationship between the frequency and the shear viscosity of the film adhesive is -0.67 or less, the exposure (bleed-out) of the film adhesive from the end of the second semiconductor element can be suppressed. . As a result, a semiconductor device having good wafer embedding properties and suppressed bleeding can be obtained.

In addition, in the adhesive films described in Patent Document 1 and Patent Document 3, the modulus of elasticity rapidly increases during thermal curing, so that the stress applied to the wafer during mounting cannot be sufficiently relieved, and the wafer may be warped together with the adhesive film. warping is a phenomenon known as wafer warpage. On the other hand, according to the manufacturing method of the semiconductor device of this invention, by using the film-form adhesive which satisfies the above-mentioned conditions, stress is hard to remain|survive in a film-form adhesive, and a wafer warpage can also be suppressed.

In the present invention, the film adhesive preferably has a shear viscosity of 25000Pa at 80°C measured under the condition of a frequency of 0.1Hz. s or more. The shear viscosity at a frequency of 0.1Hz is 25000Pa. s or more, the exposure (bleeding) of the film-like adhesive from the end portion of the second semiconductor element can be further suppressed.

In this invention, it is preferable that the said film adhesive contains the epoxy resin which is liquid at 25 degreeC as a thermosetting component. Thereby, it is easy to further improve the embeddedness of the chip.

In the present invention, the film-like adhesive preferably contains a thermoplastic component. Thereby, it is easy to further improve the embeddedness of the chip.

In the present invention, the film-like adhesive preferably contains an inorganic filler. Thereby, the handleability and the like of the film-like adhesive are improved, and the exposure (bleed-out) of the film-like adhesive from the end portion of the second semiconductor element can be further suppressed.

In addition, the present invention provides a film-like adhesive, which is electrically connected to a substrate through a first line on a first semiconductor element, and which is mounted on the first semiconductor element in a larger area than the first semiconductor element In a semiconductor device made of a second semiconductor element, the second semiconductor element is mounted and the first wire and the first semiconductor element are embedded, and 80°C measured at a frequency of 79.0 Hz Under the shear viscosity of 300Pa. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the relationship between X and Y is approximated to a power and expressed as Y=aX ^b , the slope b of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on a logarithmic graph is -0.67 or less.

According to the film adhesive of the present invention, it is possible to obtain a semiconductor device having good wafer embedding properties and suppressing bleeding. Moreover, according to the film-like adhesive of this invention, the semiconductor device which suppressed the warpage of a wafer can be obtained.

The film adhesive of the present invention preferably has a shear viscosity of 25000Pa at 80°C measured under the condition of a frequency of 0.1Hz. s or more.

The film adhesive of the present invention preferably contains a liquid epoxy resin at 25° C. as a thermosetting component.

The film adhesive of the present invention preferably contains a thermoplastic component.

The film adhesive of the present invention preferably contains an inorganic filler.

Furthermore, the present invention provides a dicing in which the film adhesive of the present invention is laminated on a dicing tape. Bonded die-integrated adhesive.

Cutting according to the present invention. Bonded die-integrated wafer, which can obtain wafer buried A semiconductor device with good ingress and suppression of exudation. In addition, according to the cutting of the present invention. The die-bonding integrated adhesive sheet can obtain a semiconductor device in which warpage of the wafer is suppressed.

Cutting of the present invention. In the die-bonding integrated adhesive sheet, the thickness of the film adhesive is preferably 20 μm˜200 μm. In order to fully embed the first semiconductor element, the first line, and the unevenness of the wiring circuit of the substrate with the film-like adhesive, a sufficient thickness is required. However, in order to reduce bleeding, the film-like adhesive is preferably thin, so both From these viewpoints, the thickness of the film-like adhesive is desirably within the above-mentioned range.

Cutting of the present invention. The die-bonding integrated adhesive sheet preferably has a cover film provided on the surface opposite to the surface on which the dicing tape of the film-like adhesive is provided. The film adhesive can be protected by having a cover film.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can combine favorable wafer embedding property and low exudation property can be provided. In addition, the present invention can provide a film-like adhesive that can be used in the production method, and cutting using the same. Bonded die-integrated adhesive.

10: Film adhesive

14: Substrate

20: substrate film

30: cover film

40: substrate film

41: Adhesive

42: Resin (sealing material)

50: Adhesive layer

60: cutting tape

84, 94: circuit pattern

88: First Line

90: Organic substrate

98: Second line

100, 110, 120, 130: After the film

200: Semiconductor Devices

Wa: first semiconductor element

Waa: Second semiconductor element

FIG. 1 is a view showing a film-like adhesive according to an embodiment of the present invention.

Fig. 2 is a view showing an adhesive sheet according to an embodiment of the present invention.

Fig. 3 is a view showing an adhesive sheet according to another embodiment of the present invention.

Fig. 4 is a cut showing another embodiment of the present invention. A diagram of a sticky die-integrated bond.

Fig. 5 is a cut showing another embodiment of the present invention. A diagram of a sticky die-integrated bond.

FIG. 6 is a diagram showing a semiconductor device.

FIG. 7 is a diagram showing a method of manufacturing the semiconductor device according to the embodiment of the present invention.

FIG. 8 is a diagram showing the subsequent steps of FIG. 7 .

FIG. 9 is a diagram showing the subsequent steps of FIG. 8 .

FIG. 10 is a diagram showing the subsequent steps of FIG. 9 .

FIG. 11 is a diagram showing the subsequent steps of FIG. 10 .

12 is a logarithmic graph showing the relationship between the shear viscosity (Y) and the frequency (X) of the film adhesives of Example 1 and Comparative Example 1. FIG.

13 is an ultrasonic diagnostic image obtained by observing the generation state of voids (voids) in the evaluation samples using the film adhesives of Example 4, Comparative Example 1, and Comparative Example 5. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same code|symbol is attached|subjected to the same or an equivalent part, and the repeated description is abbreviate|omitted. In addition, the positional relationship, such as up-down, left-right, etc., refers to the one based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown in the drawings. In addition, "(meth)acrylic acid" in this specification means "acrylic acid" and "methacrylic acid" corresponding to it.

(Film Adhesive)

FIG. 1 is a cross-sectional view schematically showing a film adhesive 10 of the present embodiment. The film-like adhesive 10 is thermosetting, and is formed by molding the adhesive composition in a semi-hardened (B-stage) state and in a fully cured (C-stage) state after a hardening process into a film.

The shear viscosity at 80° C. of the film adhesive 10 measured under the condition of a frequency of 79.0 Hz was 300 Pa. s or less. The shear viscosity at 80° C. measured at a frequency of 79.0 Hz affects the embedment of semiconductor elements and wires such as controller chips by using the film-like adhesive 10, so the value is 300Pa. s or less, low elasticity can be obtained to the extent that semiconductor elements and lines are sufficiently embedded, and favorable wafer embedding properties can be obtained. From the viewpoint of further improving the embedding property of the wafer, the shear viscosity of the film adhesive 10 at 80° C. measured under the condition of a frequency of 79.0 Hz is preferably 295Pa. s or less, more preferably 290Pa. s or less, more preferably 285Pa. s or less. In addition, from the viewpoint of further reducing the extravasation (bleeding) of the resin from the wafer end, the shear viscosity of the film adhesive 10 at 80°C measured under the condition of a frequency of 79.0Hz may be 200Pa. s above, can also be 230Pa. s above, can also be 250Pa. s or more.

In the film adhesive 10, the shear viscosity at 80° C. measured under the conditions of frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is represented by Y (Pa·s), and the frequency is represented by X ( Hz), when the power of the relationship between X and Y is approximated and expressed as Y=aX ^b , the slope b of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on the double logarithmic graph is -0.67 or less. The slope b represents the frequency dependence of the shear viscosity. The smaller the value (the larger the absolute value), the higher the frequency dependence. The greater the difference in viscosity. In addition, when the slope b is -0.67 or less, the shear viscosity of the film adhesive 10 at the moment when the semiconductor element and the wire are embedded by heating and pressing can be reduced, and the viscosity during the period from the embedding to the cooling can be reduced. The shear viscosity is relatively large, so that the resin flow can be suppressed after embedding. As a result, extravasation (bleeding) of resin from the wafer edge can be reduced. From the viewpoint of further reducing bleeding, the slope b is preferably -0.68 or less, more preferably -0.69 or less, and still more preferably -0.70 or less. In addition, from the viewpoint of not impairing the film formability and workability, the slope b may be -0.80 or more.

From the viewpoint of further reducing the extravasation (bleeding) of the resin from the wafer end, the film adhesive 10 preferably has a shear viscosity of 25000Pa at 80°C measured under the condition of a frequency of 0.1Hz. s above, more preferably 27000Pa. s above, and more preferably 29000Pa. s or more, the best is 30000Pa. s or more. In addition, the shear viscosity at 80° C. measured under the condition of a frequency of 0.1 Hz is preferably 50000 Pa from the viewpoint of film formability and processability such as cutting. s or less, more preferably 40000Pa. s or less, more preferably 35000Pa. s or less.

In the case of reducing the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film adhesive 10 , for example, by increasing the content of the component (a1) described later, the content of the component (b1) can be increased. The content is adjusted by methods such as reducing the content of the component (b2), reducing the content of the component (c), or reducing the particle size. In addition, when it is desired to increase the shear viscosity at 80° C. measured under the condition of a frequency of 0.1 Hz of the film adhesive 10 , for example, by increasing the amount of the component (a2) described later, increasing the amount of (c) The content of the component and the method of increasing the molecular weight of the component (b2) are adjusted. Furthermore, in addition to the method described above, the film adhesive 10 has a frequency of 79.0 Hz and a frequency of 79.0 Hz. The shear viscosity at 80° C. measured under the condition of 0.1 Hz can also be adjusted by adjusting the types and amounts of components (a) to (e) described later.

In the case where the slope b is to be lowered, the above-described method of adjusting the shear viscosity at a frequency of 79.0 Hz or a frequency of 0.1 Hz may also be difficult to adjust. When the inclination b is to be lowered, for example, a method of adjusting the epoxy equivalent of the epoxy resin of the component (a2) described later or the hydroxyl equivalent of the phenol resin can be mentioned. By reducing the epoxy equivalent of the epoxy resin of the component (a2) or the hydroxyl equivalent of the phenol resin, the frequency dependence of the shear viscosity of the film adhesive 10 can be improved, and the slope b tends to be further reduced. In addition, in addition to the said method, the slope b can also be adjusted by adjusting the kind and amount of (a) component - (e) component mentioned later.

The shear viscosity of the film-like adhesive 10 can be adjusted using a dynamic viscoelasticity device (for example, trade name "ARES" manufactured by TA Instruments, Inc.), while applying a 5% strain to the film-like adhesive 10 maintained at 80°C. to measure. More specifically, a parallel cone-plate jig having a diameter of, for example, 8 mm may be placed on the dynamic viscoelasticity device, and a measurement sample of the film-like adhesive 10 may be placed therein, and the measurement sample may be given a 5% While straining, the frequency was changed to 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz in a discrete mode, and the shear viscosity at each frequency was measured. The thickness of the film-like adhesive 10 used as a sample for measurement can be, for example, 440 μm. The film-like adhesive 10 used as a sample for measurement is in a state before curing (uncured state), for example, in a semi-cured (B-stage) state. In addition, conditions, such as the diameter of a parallel cone-plate jig and the thickness of the sample for a measurement, are not limited to the conditions mentioned above, You may set it as a different condition. By pre-inputting these conditions as measurement parameters into the measurement In the fixed device, the measurement result corrected for its influence can be obtained, so even if the conditions are changed, the same value can be obtained as the corrected measurement result.

The slope b can be approximated by using the shear viscosity as Y (Pa.s) and the frequency as X (Hz), based on the shear viscosity at each frequency measured by the method described above, by approximating the relation between X and Y to a power On the other hand, the value of b when expressed by Y=aX ^b is obtained. In addition, in the power approximation formula, a and b are constants, and b represents the slope of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on the logarithmic graph.

Moreover, it is preferable that the adhesive force after hardening with respect to the board|substrate which apply|coated AUS308 to the film adhesive 10 is 1.0 MPa or more. In this case, the connection reliability of the obtained semiconductor device is more favorable.

In order to set the adhesive force between the substrate coated with AUS308 and the cured film adhesive 10 to 1.0 MPa or more, for example, it can be performed by reducing the amount of the component (a2) described later and increasing the content of the inorganic filler (c). Adjustment. In addition, from the viewpoint of obtaining sufficient adhesiveness, it is preferable to add a coupling agent or the like described later.

The components contained in the film-like adhesive 10 are not particularly limited, and may include, for example, (a) thermosetting components, (b) thermoplastic components, (c) inorganic fillers, (d) curing accelerators, (e) other components, and the like . The properties of the film-like adhesive 10 can be adjusted by adjusting the types and amounts of these (a) components to (e) components.

(a) Thermosetting component

As a thermosetting component, thermosetting resin is mentioned. In particular, from the viewpoint of heat resistance and moisture resistance required when mounting a semiconductor element, epoxy resins, phenol resins, and the like are preferable as thermosetting components.

Examples of epoxy resins and phenol resins include (a1) those having a softening point of 60° C. or lower or those in a liquid state at normal temperature (25° C.), but are not particularly limited as long as they have an adhesive effect for curing. Examples of epoxy resins conforming to the component (a1) include bifunctional epoxy resins obtained by modifying bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol E type epoxy resins, and the like. Wait. Moreover, EP-4088 by ADEKA Co., Ltd., CELLOXIDE 2021P by Daicel Co., Ltd., etc. are mentioned as a phenol resin which corresponds to (a1) component.

Examples of epoxy resins and phenol resins include (a2) epoxy resins with a softening point exceeding 60°C (solid at normal temperature (25°C)) and an epoxy equivalent of 500 or less, and those having a softening point exceeding 60°C (at normal temperature). A phenolic resin having a hydroxyl equivalent weight of 300 or less. Examples of epoxy resins conforming to the component (a2) include dicyclopentadiene-type epoxy resins HP-7200L (epoxy equivalent: 242 to 252) and HP-7200 manufactured by DIC Co., Ltd. (epoxy equivalent weight is 254~264), HP-7200H (epoxy equivalent weight is 272~284), cresol novolac epoxy resin can include YDCN-700-10 ( The epoxy equivalent is 198~210) and so on. Moreover, a dicyclopentadiene-type phenol resin etc. are mentioned as a phenol resin which corresponds to (a2) component. As an example of the phenol resin which corresponds to such (a2) component, the HE series (for example, HE-100C-30 (hydroxyl equivalent: 174)) by Air Water Co., Ltd., etc. are mentioned.

From the viewpoint of reducing the value of the slope b, the epoxy equivalent of the epoxy resin and the hydroxyl equivalent of the phenol resin corresponding to the component (a2) are preferably 500 or less, more preferably 400 or less, and still more preferably 300 or less, The best is below 200. In addition, it conforms to (a2) The epoxy equivalent of the epoxy resin of the components and the hydroxyl equivalent of the phenol resin may be 100 or more.

The component (a2) is not particularly limited, but preferably contains an epoxy resin (dicyclopentadiene-type epoxy resin) having a dicyclopentadiene skeleton, or a phenol resin having a dicyclopentadiene skeleton ( Dicyclopentadiene-type phenol resin). These can also be used together. By using these, it becomes easy to further reduce the value of the inclination b of the film adhesive 10 (to further increase the absolute value). In addition, by using these, the shear viscosity at 80°C measured under the condition of a frequency of 79.0 Hz of the uncured film-like adhesive can be easily reduced, and the value of the shear viscosity measured under the condition of a frequency of 0.1 Hz is increased. Shear viscosity at 80°C, so it is easy to have good wafer embedding and low exudation.

The epoxy resin other than the above-mentioned (a1) component and (a2) component may be used together as a (a) thermosetting component. For example, novolak-type epoxy resins, such as a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, etc. can be used. Moreover, as an epoxy resin, generally known epoxy resins, such as a polyfunctional epoxy resin, a glycidylamine type epoxy resin, a heterocyclic ring-containing epoxy resin, and an alicyclic epoxy resin, can also be used.

Moreover, you may use together the phenol resin other than the above-mentioned (a1) component and (a2) component as (a) thermosetting component. Examples include: Phenolite KA and TD series manufactured by DIC Corporation; Mirex XLC series and XL series manufactured by Mitsui Chemicals Co., Ltd. (for example, Mirex XLC-LL) Wait. From the viewpoint of heat resistance, the water absorption rate after 48 hours in a constant temperature and humidity tank at 85° C. and 85% RH is preferably 2 mass % or less, as measured by a thermogravimetric analyzer (TGA). at 350°C The heating mass reduction rate (heating rate: 5°C/min, environment: nitrogen) is less than 5% by mass.

When an epoxy resin and a phenol resin are used in combination as the (a) thermosetting component, the mixing ratio of the epoxy resin and the phenol resin is preferably 0.70/0.30 in terms of the equivalent ratio of the epoxy equivalent and the hydroxyl equivalent, respectively. ~0.30/0.70, more preferably 0.65/0.35~0.35/0.65, still more preferably 0.60/0.40~0.40/0.60, particularly preferably 0.60/0.40~0.50/0.50. When the compounding ratio is within the above range, the film-like adhesive 10 having excellent curability, fluidity, and the like can be easily obtained.

The content of the component (a1) is preferably 5% by mass to 60% by mass, more preferably 10% by mass to 55% by mass, based on the total mass of the component (a). Thereby, the fluidity|liquidity of the film adhesive before hardening can be easily ensured.

The content of the component (a2) is preferably 40% by mass to 95% by mass, more preferably 45% by mass to 90% by mass, based on the total mass of the component (a). When the content of the component (a2) is within the above-mentioned range (especially, if it is more than or equal to the above-mentioned lower limit value), the temperature at 80° C. measured under the condition of a frequency of 0.1 Hz of the film-like adhesive 10 in an uncured state can be easily increased. The shear viscosity of the resin is easy to reduce the extravasation (bleeding) of the resin from the end of the wafer.

The content of the component (a) is preferably 30% by mass to 80% by mass, and more preferably 40% by mass to 60% by mass, based on the total mass of the film adhesive 10 . When the content of the component (a) is 40 mass % or more, the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film-like adhesive in an uncured state is easily reduced, and the embedding property is more favorable, and The curing properties of the thermosetting adhesive are improved, the film-like adhesive is more likely to be suppressed from peeling off from the substrate or the generation of air bubbles in the interior, and the adhesion reliability is improved. Lift. On the other hand, when content of (a) component is 80 mass % or less, it becomes easy to control the stability at the time of coating, and the reliability after mounting.

(b) Thermoplastic composition

As the thermoplastic component (b), it is preferable to use together a thermoplastic component having a crosslinkable functional group such as a glycidyl group and a high molecular weight, and a thermoplastic component having a crosslinkable functional group other than a glycidyl group, such as a carboxyl group or a hydroxyl group, and a low molecular weight. Thermoplastic composition. For example, the component (b) preferably contains (b1) a monomer unit having at least a glycidyl group as a crosslinkable functional group in an amount of 3% by mass to 15% by mass with respect to the total amount of monomer units, and a weight average molecular weight. A thermoplastic component having a glass transition temperature Tg of -50° C. to 50° C. of 700,000 to 2,000,000; and (b2) containing no glycidyl group in a ratio of 1% by mass to 7% by mass relative to the total amount of monomer units And has a crosslinkable functional group other than glycidyl group (such as carboxyl group and hydroxyl group, etc.) as a monomer unit of the crosslinkable functional group, the weight average molecular weight is 500,000 to 900,000, and the glass transition temperature Tg is -50 ℃ ~ 50 °C thermoplastic composition.

As the component (b), an acrylic resin (acrylic resin) which is a thermoplastic resin is preferable, and the glass transition temperature Tg is more preferably -50°C to 50°C, and glycidyl acrylate, glycidyl methacrylate Acrylic resins such as epoxy group-containing (meth)acrylic copolymers obtained by polymerizing a functional monomer having an epoxy group or a glycidyl group as a crosslinkable functional group are used.

As such an acrylic resin, an epoxy-group-containing (meth)acrylate copolymer, an epoxy-group-containing acrylic rubber, etc. can be used, and an epoxy-group-containing acrylic rubber is more preferable. The epoxy group-containing acrylic rubber uses acrylate as the main component, and mainly Acrylic rubbers having epoxy groups, such as copolymers of butyl acrylate and acrylonitrile, and the like, copolymers of ethyl acrylate and acrylonitrile, and the like.

Moreover, as a crosslinkable functional group of (b) component, besides an epoxy group, a crosslinkable functional group, such as an alcoholic or phenolic hydroxyl group, and a carboxyl group, can also be mentioned.

Regarding the component (b1), from the viewpoint of further improving the adhesive force after curing, the amount of monomer units having a crosslinkable functional group is preferably 3% by mass to 15% by mass, more preferably with respect to the total amount of monomer units. It is 5 mass % - 10 mass %.

Regarding the component (b2), from the viewpoint of further improving the adhesive force after curing, the amount of monomer units having a crosslinkable functional group is preferably 1% by mass to 7% by mass, more preferably with respect to the total amount of monomer units. It is 1 mass % - 5 mass %.

The weight average molecular weight of the component (b1) is preferably 700,000 or more and 2,000,000 or less. When the weight-average molecular weight of the component (b1) is 700,000 or more, the film-forming property becomes more favorable, and the adhesive strength and heat resistance of the film-like adhesive 10 can be further improved. If the weight-average molecular weight of the component (b1) is 2 million or less, the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film adhesive 10 in an uncured state tends to decrease, and thus the embedding property is improved. good.

The weight average molecular weight of the component (b2) is preferably 500,000 or more and 900,000 or less. When the weight-average molecular weight of the component (b2) is 500,000 or more, the effect of improving the film-forming properties by using together with the component (b1) is more favorable, and the frequency of the film-like adhesive 10 in the uncured state is easily increased to 0.1. The shear viscosity at 80°C measured under the condition of Hz can easily reduce the extravasation (bleeding) of the resin from the wafer edge. When the weight average molecular weight of the component (b2) is 900,000 or less, it is easy to reduce the film in the uncured state Since the shear viscosity at 80°C measured under the condition of a frequency of 79.0 Hz of the adhesive agent 10, the embedding property is more favorable. In addition, when the weight average molecular weight of the component (b2) is 900,000 or less, the machinability of the film-like adhesive 10 in an uncured state may be improved, and the cutting quality may become more favorable.

The weight average molecular weight is a polystyrene conversion value obtained by gel permeation chromatography (Gel Penetration Chromatography, GPC) using a calibration curve based on standard polystyrene.

Moreover, it is preferable that the glass transition temperature Tg of (b1) component and (b2) component is -50 degreeC - 50 degreeC. When the glass transition temperature Tg is 50° C. or lower, the flexibility of the film adhesive 10 is more favorable. On the other hand, when the glass transition temperature Tg is -50° C. or higher, the flexibility of the film adhesive 10 will not be too high, so that the film adhesive 10 is easily cut when dicing a semiconductor wafer. Therefore, it is easy to suppress the deterioration of the cutability due to the generation of burrs.

The glass transition temperature Tg of the entire component (b) is preferably -20°C to 40°C, more preferably -10°C to 30°C. As a result, the film adhesive 10 is easily cut at the time of dicing, so that resin chips are not easily generated, the adhesive force and heat resistance of the film adhesive 10 are easily improved, and the uncured state of the film adhesive 10 is easily exhibited. fluidity.

The glass transition temperature Tg can be measured using a thermal differential scanning calorimeter (for example, "Thermo Plus 2" manufactured by Rigaku Co., Ltd.).

(b) A component can also be acquired as a commercial item. For example, as the component (b1), acrylic rubber HTR-860P-3CSP (trade name, manufactured by Nagase ChemteX Co., Ltd.) and the like can be mentioned. The compound has a condensed The hydroglyceryl moiety is a crosslinkable moiety, and a compound having an acrylic rubber containing an acrylic derivative as a matrix resin has a weight average molecular weight of 1 million and a glass transition temperature Tg of 15°C. Moreover, as (b2) component, SG-708-6 (brand name, the Nagase Chemical Co., Ltd. make) etc. are mentioned. This compound has a carboxyl group and a hydroxyl group and is based on an acrylic rubber, and has a weight average molecular weight of 700,000 and a glass transition temperature Tg of 4°C.

The content of the component (b1) is preferably 50% by mass or more, more preferably 55% by mass to 90% by mass, based on the total mass of the component (b). If the content of the component (b1) is 50 mass % or more, the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film-like adhesive 10 in an uncured state is likely to decrease, so that the embedding property is more favorable. . On the other hand, when the content of the component (b1) is 90 mass % or less, the adhesive strength after hardening is more favorable.

The content of the component (b2) is preferably 10% by mass or more, more preferably 10% by mass to 45% by mass, based on the total mass of the component (b). If the content of the component (b2) is within the above range, the film adhesive 10 in the uncured state will be cured in a state where the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz is maintained. A good hardened product can be obtained.

The content of the component (b) is preferably 20 parts by mass to 80 parts by mass, more preferably 30 parts by mass to 50 parts by mass, relative to 100 parts by mass of the component (a). When content of (b) component is 30 mass parts or more, the fall of the flexibility of a film-form adhesive agent can be suppressed, and it becomes easy to achieve high elasticity after heating, and can suppress bleeding. On the other hand, when the content of the component (b) is 80 parts by mass or less, it is easy to reduce the uncured state. The shear viscosity at 80°C measured under the condition of a frequency of 79.0 Hz of the film-like adhesive 10 has further improved fluidity, and thus better embedding properties.

(c) Inorganic filler

As the component (c), the cutting properties of the film adhesive 10 in the B-stage state are improved, the handleability of the film adhesive 10 is improved, the thermal conductivity is improved, the shear viscosity (melt viscosity) is adjusted, and the touch From the viewpoints of imparting denaturation, improving adhesion, and the like, silica fillers and the like are preferred.

The component (c) preferably contains two or more fillers having different average particle diameters for the purpose of improving the cutability of the uncured film adhesive 10 and sufficiently developing the adhesive force after curing. As the component (c), for example, (c1) a first filler having an average particle diameter of 0.2 μm or more for the purpose of improving the cutability of the film adhesive 10 in an uncured state, and (c2) for sufficiently expressing curing The second filler having an average particle diameter of less than 0.2 μm for the purpose of the subsequent adhesive force may be used alone or in combination as long as the cutting properties and the adhesive force can be ensured.

The average particle diameter is a value obtained when analyzed using a laser diffraction particle size distribution analyzer using acetone as a solvent. When the average particle diameter of the first filler and the second filler is analyzed by a particle size distribution analyzer, it is more preferable that the difference is large within the extent that each filler can be determined to be included.

When used in combination with the component (c2), the content of the component (c1) is preferably 30% by mass or more based on the total mass of the component (c). When the content of the component (c1) is 30% by mass or more, it is easy to suppress the deterioration of the cutability of the film and the deterioration of the fluidity of the film-like adhesive 10 in an uncured state.

When used in combination with the component (c1), the content of the component (c2) is preferably 50% by mass or more based on the total mass of the component (c). When the content of the component (c2) is 50 mass % or more, the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film adhesive 10 in an uncured state is easily reduced, so that the embedding property is improved. Good, and it is easy to fully develop the adhesive force after hardening.

The average particle diameter of the entire component (c) is preferably 0.05 μm to 0.5 μm, more preferably 0.2 μm to 0.4 μm. When the average particle diameter of the whole component (c) is within the above-mentioned range, the shear viscosity at 80° C. measured under the condition of a frequency of 79.0 Hz of the film-like adhesive 10 in an uncured state can be easily reduced and embedded. Sex is better.

The content of the component (c) is preferably 30 parts by mass to 70 parts by mass, more preferably 40 parts by mass to 65 parts by mass, relative to 100 parts by mass of the component (a). When the content of the component (c) is equal to or greater than the lower limit value, the deterioration of the cutability of the film adhesive 10 in the uncured state and the decrease in the adhesive force after curing can be easily suppressed, and the uncured state can be easily improved. The shear viscosity at 80° C. of the film-like adhesive 10 measured under the condition of a frequency of 0.1 Hz tends to reduce the tendency of resin to ooze out (bleed out) from the wafer edge. On the other hand, when the content of the component (c) is equal to or less than the upper limit value, the shearing at 80° C. measured under the condition of a frequency of 79.0 Hz of the film-like adhesive 10 in an uncured state is easily reduced. The viscosity and embedment are more favorable, and the tendency to increase the elastic modulus after hardening is easily suppressed.

(d) Hardening accelerator

For the purpose of obtaining good hardening properties, (d) a hardening accelerator is preferably used. As the component (d), an imidazole-based compound is preferred from the viewpoint of reactivity. In addition, when the reactivity of the component (d) is too high, not only the shear viscosity tends to increase easily, but also deterioration over time tends to be easily caused by heating in the production process of the film adhesive 10 . On the other hand, when the reactivity of the component (d) is too low, the curability of the film-like adhesive 10 tends to decrease easily. When the film-like adhesive 10 is mounted in a product without being sufficiently cured, sufficient adhesiveness cannot be obtained, and there is a possibility that the connection reliability of the semiconductor device may be deteriorated.

Moreover, when content of (d) component is too small, there exists a tendency for the curability of the film adhesive 10 to fall easily. On the other hand, when there is too much content of (d) component, there exists a tendency for not only the shear viscosity to rise easily but also to deteriorate easily with time by heating in the manufacturing process of the film adhesive 10. From such a viewpoint, it is preferable that content of (d) component is 0 mass part - 0.20 mass part with respect to 100 mass parts of (a) components, More preferably, it is 0.05 mass part - 0.20 mass part.

(e) Other ingredients

In addition to the above-mentioned components, an appropriate amount of other components that can be used in the technical field may be used from the viewpoint of improving adhesion. As such a component, a coupling agent is mentioned, for example. As the coupling agent, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-(2-aminoethyl group) aminopropyl trimethoxysilane, etc.

The content of the coupling agent is preferably 0 to 5 parts by mass, more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the component (a). When the content of the coupling agent is greater than or equal to the lower limit value, the wettability to the wafer surface or the substrate as an adherend tends to be improved, and the adhesion and reliability tend to be improved. On the other hand, by even When the content of the mixture is equal to or less than the above upper limit value, the generation of air bubbles accompanying expansion during heating tends to be easily suppressed.

(Film Adhesive)

The film-like adhesive 10 can be obtained by, for example, the following steps: a step of forming a varnish layer by applying a varnish of the adhesive composition containing the above-mentioned components on a base film; self-varnishing by heat drying The step of removing the solvent for the layer and the step of removing the base film.

The varnish can be prepared by mixing, kneading, etc., the adhesive composition containing the above-mentioned components in an organic solvent. For mixing and kneading, a dispersing machine such as a normal mixer, a kneader, a three-roll mill, and a ball mill can be used. These devices can be used in appropriate combination. The coating of the varnish can be performed by, for example, a coater. The heating and drying conditions of the varnish are not particularly limited as long as the organic solvent used is sufficiently volatilized, and for example, it can be heated at 60° C. to 200° C. for 0.1 minutes to 90 minutes.

As the organic solvent, any conventionally known organic solvent can be used without limitation as long as the components can be uniformly dissolved, kneaded, or dispersed. Examples of such solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; dimethylformamide, dimethylacetamide, N-methyl Pyrrolidone, toluene, xylene, etc. In terms of high drying rate and low price, methyl ethyl ketone, cyclohexanone, etc. are preferably used.

The base film is not particularly limited, and examples thereof include polyester films (polyethylene terephthalate films, etc.), polypropylene films (oriented polypropylene (Oriented PolyPropylene, OPP) films, etc.), polyamide films, etc. Amine film, polyetherimide film, polyether Naphthalene dicarboxylate film, methyl pentene film, etc.

The thickness of the film-like adhesive 10 is preferably 20 μm to 200 μm in order to sufficiently embed the first line, the first semiconductor element, and the unevenness of the wiring circuit of the substrate. In addition, when the thickness is 20 μm or more, it is easy to obtain a sufficient adhesive force, and when the thickness is 200 μm or less, it is easy to meet the requirements for miniaturization of semiconductor devices. From such a viewpoint, the thickness of the film adhesive 10 is more preferably 30 μm to 200 μm, and still more preferably 40 μm to 150 μm.

As a method of obtaining the thick film-like adhesive agent 10, the method of bonding the film-like adhesive agents 10 to each other is mentioned.

(Continued film)

As shown in FIG. 2 , the adhesive sheet 100 has a film-like adhesive 10 on the base film 20 . The subsequent sheet 100 can be obtained by not removing the base film 20 in the step of obtaining the film-like adhesive 10 .

As shown in FIG. 3 , the adhesive sheet 110 further includes a cover film 30 on the surface of the adhesive sheet 100 on the opposite side to the base film 20 . As the coverlay film 30, a polyethylene terephthalate (PET) film, a polyethylene (PE) film, an OPP film, etc. are mentioned, for example.

The film adhesive 10 may also be laminated on the dicing tape. By using the cut thus obtained. The die-bonding type adhesive chip can perform the lamination step on the semiconductor wafer at one time, which can realize the efficiency of the operation.

Examples of the dicing tape include polytetrafluoroethylene films, polyethylene terephthalate films, polyethylene films, polypropylene films, polymethylpentene films, and polyimide films. and other plastic films. Surface treatments such as primer treatment, UV treatment, corona discharge treatment, grinding treatment, and etching treatment can also be performed on the dicing tape as required.

The dicing tape is preferably adhesive. As such a dicing tape, one that imparts adhesiveness to the plastic film and one that is provided with an adhesive layer on one side of the plastic film can be mentioned.

as such a cut. The die-bonding integrated adhesive sheet includes the adhesive sheet 120 shown in FIG. 4 and the adhesive sheet 130 shown in FIG. 5 . As shown in FIG. 4 , the adhesive sheet 120 has a structure in which a dicing tape 60 provided with an adhesive layer 50 on a base film 40 that can ensure elongation when tension tension is applied is used as a supporting base material, and is used for cutting The film-like adhesive 10 is provided on the adhesive layer 50 of the tape 60 . As shown in FIG. 5 , the adhesive sheet 130 has a structure in which the base film 20 is further provided on the surface of the film-like adhesive 10 in the adhesive sheet 120 .

Examples of the base film 40 include the plastic films described in relation to the dicing tape. In addition, the adhesive layer 50 can be formed using, for example, a resin composition containing a liquid component and a thermoplastic component and having an appropriate adhesive strength. In order to obtain the dicing tape 60, a method of applying the resin composition on the base film 40 and drying to form the adhesive layer 50 can be mentioned; A method of bonding the base film 40, and the like.

As a method of laminating the film-like adhesive 10 on the dicing tape 60, there may be mentioned: a method of directly coating the varnish of the adhesive composition on the dicing tape 60 and drying it; screen printing the varnish on the dicing tape 60 The method above; pre-fabricating the film adhesive 10, and laminating it on the dicing tape 60 by pressing and laminating with a hot roll law, etc. Lamination by hot roll lamination is preferable in terms of continuous production and high efficiency.

The thickness of the cutting tape 60 is not particularly limited, and can be cut according to the thickness of the film adhesive 10 and cutting. The purpose of the bonding die-integrated adhesive sheet is appropriately determined based on the knowledge of those skilled in the art. In addition, since the thickness of the dicing tape 60 is 60 μm or more, it is easy to suppress the drop in workability and the expansion in the step of peeling off the semiconductor element singulated by dicing from the dicing tape 60 . Tendency to crack, etc. On the other hand, when the thickness of the dicing tape is 180 μm or less, the advantages of economy and workability can be easily achieved. From the above, the thickness of the dicing tape 60 is preferably 180 μm or less, and more preferably 60 μm to 180 μm.

(semiconductor device)

6 is a cross-sectional view showing a semiconductor device. As shown in FIG. 6 , the semiconductor device 200 is a semiconductor device in which a second semiconductor element Waa is stacked on a first semiconductor element Wa. Specifically, the first semiconductor element Wa of the first stage is electrically connected to the substrate 14 via the first wires 88 , and is mounted (crimped) on the first semiconductor element Wa via the film adhesive 10 . The second semiconductor element Waa of the second stage having a larger area of the first semiconductor element Wa is a wire-embedded type (wafer) in which the first wire 88 and the first semiconductor element Wa are embedded in the film adhesive 10 . embedded type) semiconductor device. In addition, in the semiconductor device 200 , the substrate 14 and the second semiconductor element Waa are further electrically connected via the second wires 98 , and the second semiconductor element Waa is sealed by the sealing material 42 .

The thickness of the first semiconductor element Wa is 10 μm to 170 μm, and the second half The thickness of the conductor element Waa is 20 μm to 400 μm. The first semiconductor element Wa embedded in the film adhesive 10 is a controller wafer for driving the semiconductor device 200 .

The substrate 14 includes the organic substrate 90 on which the circuit pattern 84 and the circuit pattern 94 are formed on the surface. The first semiconductor element Wa is mounted (crimped) on the circuit pattern 94 via the adhesive 41, and the second semiconductor element Waa covers the circuit pattern 94 and the first semiconductor element Wa on which the first semiconductor element Wa is not mounted (crimped). , and a part of the circuit pattern 84 are mounted on the substrate 14 via the film adhesive 10 (pressure-bonded). The unevenness caused by the circuit pattern 84 and the circuit pattern 94 on the substrate 14 is embedded in the film-like adhesive 10 . Then, the second semiconductor element Waa, the circuit pattern 84 and the second wire 98 are sealed with the resin-made sealing material 42 .

(Manufacturing method of semiconductor device)

The semiconductor device can be manufactured by the following method for manufacturing a semiconductor device. The manufacturing method includes: a first mounting step, in which the first semiconductor element is electrically connected to the substrate via a first wire; and a lamination step, which is compared with the first step A film-like adhesive was attached to one side of the second semiconductor element with a larger area of the semiconductor element, and the shear viscosity of the film-like adhesive at 80° C. measured under the condition of a frequency of 79.0 Hz was 300 Pa. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the relationship between X and Y is approximated to a power and expressed as Y=aX ^b , the slope b is -0.67 or less; and in the second mounting step, the film-shaped adhesive is placed so that the first semiconductor element is covered with a film-shaped adhesive. The second semiconductor element of the adhesive is press-bonded with the film-like adhesive, whereby the first wire and the first semiconductor element are embedded in the film-like adhesive. Hereinafter, a specific description will be given by taking the manufacturing process of the semiconductor device 200 as an example.

First, as shown in FIG. 7 , the first semiconductor element Wa with the adhesive 41 is mounted on the circuit pattern 94 on the substrate 14 , and the circuit pattern 84 on the substrate 14 and the first semiconductor element are connected via the first wires 88 . Wa is electrically connected (first installation step).

Next, the adhesive sheet 100 is laminated on one side of a semiconductor wafer (eg, 8 inches in size, 50 μm thick), and the base film 20 is peeled off, thereby attaching the film adhesive 10 to one side of the semiconductor wafer. Then, after attaching the dicing tape 60 to the film-like adhesive 10, it is cut into a predetermined size (for example, 7.5 mm square), and the dicing tape 60 is peeled off, whereby as shown in FIG. 8, a film-like adhesive is obtained. The second semiconductor element Waa of the agent 10 is followed (lamination step).

The lamination step is preferably performed at 50°C to 100°C, more preferably 60°C to 80°C. When the temperature of the lamination step is 50° C. or higher, good adhesion to the semiconductor wafer can be obtained. If the temperature of the lamination step is 100° C. or lower, the excessive flow of the film adhesive 10 in the lamination step can be suppressed, and thus variation in thickness and the like can be prevented from being caused.

Examples of the dicing method include a method of blade dicing using a rotating blade, a method of cutting the film-like adhesive 10 or both the wafer and the film-like adhesive 10 by a laser, and a method of dicing under normal temperature or cooling conditions. general methods such as stretching, etc.

Then, the second semiconductor element Waa to which the film adhesive 10 is attached is mounted (crimped) on the base to which the first semiconductor element Wa is connected via the first wires 88 . plate 14. Specifically, as shown in FIG. 9 , the second semiconductor element Waa to which the film-shaped adhesive 10 is attached is placed so that the film-shaped adhesive 10 covers the first semiconductor element Wa, and then, as shown in FIG. 10 , by The second semiconductor element Waa is fixed to the substrate 14 by pressing the second semiconductor element Waa to the substrate 14 (second mounting step). In the second mounting step, the film adhesive 10 is preferably crimped for 0.5 seconds to 3.0 seconds under the conditions of 80° C. to 180° C. and 0.01 MPa to 0.50 MPa. After the second mounting step, the film adhesive 10 may be further pressurized and heated for 5 minutes or more under the conditions of 60° C. to 175° C. and 0.3 MPa to 0.7 MPa.

Next, as shown in FIG. 11 , after the substrate 14 and the second semiconductor element Waa are electrically connected through the second wires 98 , the circuit pattern is formed by the sealing material 42 under the conditions of 170° C. to 180° C. and 5 MPa to 8 MPa. 84. The second wire 98 and the second semiconductor element Waa are integrally sealed (sealing step). By going through such steps, the semiconductor device 200 can be manufactured.

As described above, the semiconductor device 200 can be fabricated using a film-like adhesive that is electrically connected to the substrate on the first semiconductor element through the first wire, and that is mounted on the first semiconductor element with a higher In a semiconductor device comprising a second semiconductor element with a larger area of the semiconductor element, for mounting the second semiconductor element and burying the first line and the first semiconductor element, 80°C measured at a frequency of 79.0 Hz Under the shear viscosity of 300Pa. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the power of the relation between X and Y is approximated and expressed as Y=aX ^b , the slope b is -0.67 or less. By using the film-like adhesive that satisfies the above-mentioned conditions, in the second mounting step, the generation of voids can be suppressed and the film-like adhesive can be used to embed the first semiconductor element and the first line, and the film-like adhesive can be suppressed at the same time. Extravasation (bleeding) from the end portion of the second semiconductor element. In addition, by using the film-like adhesive that satisfies the above-mentioned conditions, it is difficult for the stress to remain in the film-like adhesive in the second mounting step, and the warpage of the second semiconductor element together with the film-like adhesive can be suppressed.

The preferred embodiments of the present invention have been described above, but the present invention is not necessarily limited to the above-described embodiments. For example, as described below, appropriate changes may be made without departing from the gist.

In the semiconductor device 200, the substrate 14 is an organic substrate 90 with circuit patterns 84 and two circuit patterns 94 formed on the surface.

The semiconductor device 200 has a structure in which the second semiconductor element Waa is laminated on the first semiconductor element Wa, and the semiconductor element is laminated in two stages, but the structure of the semiconductor device is not limited to this. A third semiconductor element may be further laminated on the second semiconductor element Waa, or a plurality of semiconductor elements may be further laminated on the second semiconductor element Waa. As the number of stacked semiconductor elements increases, the capacity of the obtained semiconductor device can be increased.

In the manufacturing method of the semiconductor device of the present embodiment, in the lamination step, the adhesive sheet 100 shown in FIG. 2 is laminated on one side of the semiconductor wafer, and the base film 20 is peeled off, thereby attaching the film. Although the adhesive 10 is used for lamination, the adhesive sheet used for lamination is not limited to this. The cutting shown in FIGS. 4 and 5 can be used instead of the adhesive sheet 100 . sticky The monolithic bonding sheet 120 and the bonding sheet 130 are formed. In this case, when dicing the semiconductor wafer, it is not necessary to attach the dicing tape 60 separately.

In the lamination step, instead of laminating the semiconductor wafers, semiconductor elements obtained by singulating the semiconductor wafers may be laminated on the adhesive sheet 100 . In this case, the cutting step can be omitted.

[Example]

Hereinafter, an Example is given and this invention is demonstrated more concretely. However, the present invention is not limited to the following examples.

(Example 1 to Example 4 and Comparative Example 1 to Comparative Example 8)

With the product names and composition ratios (unit: parts by mass) shown in Tables 1 and 2, each component was prepared in accordance with the following procedure to prepare a varnish. First, an epoxy resin, a phenol resin, and an inorganic filler as thermosetting resins are respectively weighed to obtain a composition, and cyclohexanone is further added and stirred and mixed. After adding and stirring acrylic rubber as a thermoplastic resin, a coupling agent and a hardening accelerator were further added and stirred until each component became uniform, thereby obtaining a varnish. In addition, the product name of each component in Table 1 and Table 2 means the following.

(epoxy resin)

HP-7200L: trade name, manufactured by DIC Co., Ltd., dicyclopentadiene epoxy resin, epoxy equivalent 242~252, softening point 50℃~60℃, solid at 25℃

VG3101L: trade name, manufactured by Printec Co., Ltd., multifunctional epoxy resin, epoxy equivalent of 210, softening point of 39°C to 46°C, 25°C solid state

YDCN-700-10: trade name, manufactured by New Daily Chemical Epoxy Manufacturing Co., Ltd., o-cresol novolac epoxy resin, epoxy equivalent is 210, softening point is 75℃~85℃, solid at 25℃

EXA-830CRP: manufactured by DIC Co., Ltd., bisphenol F type epoxy resin, epoxy equivalent 155~163, molecular weight 298.3, liquid at 25°C

CELLOXIDE 2021P: trade name, manufactured by Daicel Co., Ltd., 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, epoxy equivalent is 128~ 145, molecular weight 252.3, liquid at 25°C

(Phenolic resin)

HE-100C-30: trade name, manufactured by Air Water Co., Ltd., phenol resin, hydroxyl equivalent of 175, softening point of 79°C, water absorption rate of 1 mass %, heating mass reduction rate of 4 mass %, at 25° C. solid state

(inorganic filler)

SC2050-HLG: trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion, average particle size 0.50 μm

(organic filler)

EXL-2655: trade name, manufactured by Rohm and Haas Japan Co., Ltd., core-shell type organic microparticles, with an average particle size of 200 μm

X-52-854: trade name, manufactured by Shin-Etsu Chemical Co., Ltd., silicone resin powder, average particle size 0.7 μm

X-52-7030: Trade name, manufactured by Shin-Etsu Chemical Co., Ltd., silicone Composite powder with an average particle size of 0.8 μm

(coupling agent)

A-189: Trade name, manufactured by Momentive Performance Materials Japan Co., Ltd., γ-mercaptopropyltrimethoxysilane

A-1160: Trade name, manufactured by Momentive High-tech Materials Co., Ltd., γ-ureidopropyl triethoxysilane

(hardening accelerator)

2PZ-CN: Trade name, manufactured by Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole

(acrylic rubber)

HTR-860P-3CSP: Sample name, manufactured by Nagase Chemical Co., Ltd., weight average molecular weight 1 million, glycidyl functional monomer ratio 3 mass %, Tg 15°C

SG-708-6: Sample name, manufactured by Nagase Chemical Co., Ltd., weight-average molecular weight of 700,000, acid value of 9 mgKOH/g, and Tg of 4°C

Next, the obtained varnish was filtered with a 100-mesh filter, and vacuum defoamed was performed. The varnish after vacuum defoaming was apply|coated on the polyethylene terephthalate (PET) film (thickness 38 micrometers) which performed the mold release process as a base film. Using a coating machine (manufactured by Techno Smart Co., Ltd., the model number is unknown because it is a custom product), the coating was carried out at a coating speed of 1 m/min. The applied varnish was heated and dried in two stages at 90°C for 5 minutes and then at 140°C for 5 minutes. In this way, a PET film having a thickness of 20 μm in a B-stage state was obtained. An adhesive film of a film-like adhesive (first film-like adhesive). Next, the obtained adhesive film and a dicing tape (manufactured by Hitachi Maxell Co., Ltd., trade name: SD-3004) provided with an adhesive layer (thickness 30 μm) on the base film (thickness 90 μm) ), the surface of the film adhesive side of the adhesive film and the surface of the adhesive layer side of the dicing tape are adhered so that the first dicing is obtained. Bonded die-integrated adhesive. In addition, except that the thickness of the film-like adhesive was changed to 110 μm, a second cut of the second film-like adhesive with a thickness of 110 μm was obtained in the same manner as described above. Bonded die-integrated adhesive.

<Evaluation of various physical properties>

The cut obtained is as described below. Bonded die-integrated adhesive sheets were evaluated. The evaluation results are shown in Tables 1 and 2.

[Determination of Shear Viscosity]

The shear viscosity of the film adhesive was evaluated by the following method. The substrate film and cutting tape are cut from the first. The die-bonding integrated adhesive sheet was peeled off, and only the first film-like adhesive (thickness 110 μm) was taken out, and the first film-like adhesive was placed on a heating plate maintained at 70°C, and the same first film adhesive was thermally laminated thereon. Film adhesive. This was repeated four times to prepare a laminated sample of a film adhesive with a thickness of 440 μm. This laminated sample was punched out into a circular shape with a diameter of 8 mm, whereby a sample for measurement of 8 mmΦ and a thickness of 440 μm was obtained. A parallel cone-plate jig with a diameter of 8 mm was set on a dynamic viscoelasticity apparatus ARES (manufactured by TA Instruments), and a sample for measurement was set therein. During the measurement, the frequency was changed to 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz in a discrete mode while applying a strain of 5% to the sample for measurement at 80°C, and the shear viscosity at each frequency was measured.

Let the shear viscosity be Y (Pa.s) and the frequency be X (Hz), and from the measured shear viscosity at each frequency, the relation between X and Y is approximated to a power and expressed as Y= ^aXb , find the value of b. Here, a and b are constants, and b represents the slope of a power approximation curve of X and Y when the coordinates (X, Y) are plotted on a logarithmic graph. These results are shown in Table 1 and Table 2. 12 shows a double logarithmic graph showing the relationship between the shear viscosity and the frequency of the film adhesives of Example 1 and Comparative Example 1.

[Preparation of Evaluation Samples]

The embedding property and the amount of exudation of the film adhesive were evaluated by the following methods. The first cut. The substrate film on the first film-like adhesive side of the die-bonding integrated adhesive sheet is peeled off, and a semiconductor wafer (silicon wafer) with a thickness of 50 μm and a wafer ring are attached to the first film-like adhesive at a step temperature of 70°C agent to make cutting samples. Next, the cut sample was cut using a full auto dicer DFD-6361 (trade name, manufactured by Disco Co., Ltd.). It was carried out under the cutting conditions of 40,000 rpm of blade rotation, 50 mm/sec of cutting speed, and 3.2 mm x 5.5 mm of wafer size, and picked up small pieces from the cut sample, thereby obtaining a film with a first film-like shape. The first semiconductor element of the adhesive (thickness 20 μm).

Use the second cut. A die-bonding integrated adhesive sheet is used, and a semiconductor wafer with a thickness of 100 μm is used, and the wafer size is 5.7 mm × 12 mm. A second semiconductor element with a second film-like adhesive (thickness 110 μm) was obtained in the same manner as the method for the semiconductor element.

The obtained first semiconductor element with the first film adhesive and The second semiconductor element with the second film-like adhesive was mounted on a film coated with AUS308 (Sun Holdings Co., Ltd.) manufactured by the company, with a thickness of 260 μm) on the evaluation substrate. Regarding the mounting conditions, first, the first semiconductor element with the first film adhesive was press-bonded under the conditions of 120° C., 1 second, and 0.3 MPa, and the first semiconductor element was embedded thereon at 120° C. The second semiconductor element with the second film-like adhesive was press-bonded under the conditions of °C, 1.5 seconds, and 0.2 MPa. At this time, the alignment is performed so that the first semiconductor element is positioned at the center of the second semiconductor element. Thereby, an evaluation sample was obtained.

[Evaluation of oozing amount]

About the evaluation sample obtained by the said method, the upper surface of the 2nd semiconductor element was observed using the microscope (Keyence Corporation make, trade name: VHX-5000). From the end of the second semiconductor element as a starting point, the exposure width of the second film-like adhesive from the end was measured to obtain the amount of bleeding (μm). At this time, the maximum value of the exposed width was defined as the amount of bleeding. The results are shown in Tables 1 and 2.

[Evaluation of Implantability]

(Embeddability before hardening)

The evaluation sample obtained by the above method was observed at 75 MHz and reflection mode using an ultrasonic digital image diagnostic apparatus (manufactured by Insight Co., Ltd., trade name: IS-350) for the entire sample. The embedding property before hardening was evaluated based on whether or not voids were confirmed inside the layer of the second film-like adhesive. by the following Benchmark to evaluate embedment. The results are shown in Tables 1 and 2. 13 shows ultrasonic diagnostic images obtained by observing the generation state of voids (voids) in the evaluation samples using the film-like adhesives of Example 4, Comparative Example 1, and Comparative Example 5.

⊚: No voids (voids) were recognized.

○: The area ratio of voids (voids) is less than 5% with respect to the area obtained by excluding the area of the first semiconductor wafer from the area of the second film-like adhesive after mounting.

Δ: The area ratio of voids (voids) is 5% or more and less than 10% with respect to the area obtained by excluding the area of the first semiconductor wafer from the area of the second film-like adhesive after mounting.

×: The area ratio of voids (voids) is 10% or more with respect to the area obtained by excluding the area of the first semiconductor wafer from the area of the second film-like adhesive after mounting.

(Embeddability after hardening)

After the evaluation of the embeddability before curing, the evaluation sample was put into a pressurized oven, and heat-treated at 140° C. and 0.6 MPa for 45 minutes to cure the second film-like adhesive. After curing, the embeddability after curing was evaluated by the same method as the embeddability before curing. The results are shown in Tables 1 and 2.

As can be seen from the results shown in Tables 1 and 2, Examples 1 to Implementation In Example 4, the ratio of voids was 5% or less in the evaluation of embeddability before curing, and no voids were recognized in the evaluation of embeddability after pressure oven curing, and the amount of exudation was 70 μm or less. On the other hand, in Comparative Example 1, the ratio of voids in the evaluation of the embeddability before hardening was 5% or more and less than 10%, and the amount of exudation was approximately 2 times larger than that of the Examples. In addition, in Comparative Example 2 to Comparative Example 4, the amount of exudation was 80 μm or more. In addition, in Comparative Examples 5 to 8, the ratio of voids in the evaluation of embeddability before curing was 10% or more, and voids did not disappear even after curing in a pressurized oven.

10: Film adhesive

Claims (13)

A method for manufacturing a semiconductor device, comprising: a first mounting step of electrically connecting a first semiconductor element to a substrate via a first wire; a lamination step of placing a first semiconductor element on a second area larger than the first semiconductor element. A film-shaped adhesive is attached to one side of two semiconductor elements; and in a second mounting step, a second film-shaped adhesive to which the film-shaped adhesive is attached is placed so that the film-shaped adhesive covers the first semiconductor element. semiconductor element, to mount the film-like adhesive, whereby the first wire and the first semiconductor element are embedded in the film-like adhesive, and the film-like adhesive is under the condition of a frequency of 79.0 Hz The measured shear viscosity at 80°C is 300Pa. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the relationship between X and Y is approximated to a power and expressed as Y=aXb, the slope ^b of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on a logarithmic graph is -0.67 or less. The method for manufacturing a semiconductor device according to claim 1, wherein the shear viscosity of the film-like adhesive at 80° C. measured at a frequency of 0.1 Hz is 25,000 Pa. s or more. The method for manufacturing a semiconductor device according to claim 1 or claim 2, wherein the film-like adhesive contains a liquid epoxy resin at 25° C. as a thermosetting component. The method for manufacturing a semiconductor device according to claim 1 or claim 2, wherein the film-like adhesive contains a thermoplastic component. The method for manufacturing a semiconductor device according to claim 1 or claim 2, wherein the film-like adhesive contains an inorganic filler. A film adhesive, which electrically connects a first semiconductor element to a substrate through a first wire, and mounts a second semiconductor element with a larger area than the first semiconductor element on the first semiconductor element Shear viscosity at 80°C measured under the condition of a frequency of 79.0 Hz for mounting the second semiconductor element and embedding the first wire and the first semiconductor element in the semiconductor device thus obtained is 300Pa. s or less, and when the shear viscosity at 80°C measured at frequencies of 0.1 Hz, 1.0 Hz, 10.0 Hz, and 79.0 Hz is Y (Pa·s), and the frequency is X (Hz), When the relationship between X and Y is approximated to a power and expressed as Y=aX ^b , the slope b of the power approximation curve of X and Y when the coordinates (X, Y) are plotted on a logarithmic graph is -0.67 or less. The film-like adhesive described in item 6 of the scope of the application has a shear viscosity of 25000Pa at 80°C measured under the condition of a frequency of 0.1Hz. s or more. The film adhesive according to claim 6 or claim 7, which contains a liquid epoxy resin at 25° C. as a thermosetting component. The film adhesive according to claim 6 or claim 7, comprising a thermoplastic component. According to the film-like adhesive described in item 6 or item 7 of the scope of the application, It contains inorganic fillers. An adhesive sheet, which is to laminate the film-like adhesive described in any one of items 6 to 10 of the scope of the patent application on a dicing tape for cutting. Bonded die-integrated adhesive. The adhesive sheet according to claim 11, wherein the film-like adhesive has a thickness of 20 μm to 200 μm. The adhesive sheet according to claim 11 or claim 12, which has a coverlay provided on the surface opposite to the surface on which the dicing tape of the film-like adhesive is provided.

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