KR20210008341A - Semiconductor devices, thermosetting resin compositions and dicing die bonding integral tapes used in their manufacturing - Google Patents

Abstract

A semiconductor device according to the present disclosure includes a substrate, a first semiconductor element disposed on the substrate, a first sealing layer sealing the first semiconductor element, and a surface opposite to the substrate side in the first sealing layer. The second semiconductor element is disposed so as to cover and has a larger area than the first semiconductor element, the first sealing layer is made of a cured product of a thermosetting resin composition, and the melt viscosity of the thermosetting resin composition at 120°C is 2500 It is ∼11500 Pa·s.

Description

Semiconductor devices, thermosetting resin compositions and dicing die bonding integral tapes used in their manufacturing

The present disclosure relates to a semiconductor device, and a thermosetting resin composition and a dicing die-bonding integrated tape used in the manufacture thereof.

BACKGROUND ART As devices such as mobile phones become more versatile, stacked multi-chip packages (MCPs) in which semiconductor elements are stacked in multiple layers to increase capacity are spreading. Film adhesives are widely used for mounting semiconductor devices. As an example of a multistage laminated package using a film adhesive, a wire-embedded package may be mentioned. This package is manufactured through a process of burying the semiconductor element and the wire in the film adhesive by pressing a film adhesive to the semiconductor element on which the wire bonding has been completed on the substrate.

Connection reliability is one of the important characteristics required for semiconductor devices such as the stacked MCP. In order to improve the connection reliability, development of a film adhesive in consideration of properties such as heat resistance, moisture resistance, and reflow resistance has been made. For example, Patent Document 1 discloses an adhesive sheet having a thickness of 10 to 250 µm containing a thermosetting component and a filler. Patent Document 2 discloses an adhesive composition containing an acrylic copolymer and a mixture containing an epoxy resin and a phenol resin.

The reliability of the connection of a semiconductor device is also greatly influenced by whether or not a semiconductor element is mounted without generating voids (voids) on the adhesive surface. For this reason, a high-flow film adhesive can be used to compress the semiconductor element without generating voids, or a film adhesive having a low melt viscosity to eliminate the voids generated in the sealing process of the semiconductor element. Countermeasures such as the use of are being taken. For example, in Patent Document 3, an adhesive sheet having a low viscosity and low tack strength is disclosed.

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

The adhesive sheets of Patent Documents 1 and 3 contain a relatively large amount of epoxy resin for the purpose of high fluidization in order to embed a wire during compression bonding. For this reason, thermal curing is likely to proceed due to heat generated during the semiconductor device manufacturing process. Accordingly, the adhesive film becomes highly elastic, in other words, the adhesive sheet becomes difficult to deform even under high temperature and high pressure conditions at the time of sealing, and voids formed at the time of compression may not be finally lost. On the other hand, since the adhesive composition of Patent Literature 2 has a low elastic modulus, voids can be eliminated in the sealing step, but due to its high viscosity, the wire embedding property during crimping is likely to be insufficient.

In recent years, it is important to increase the operation speed of a wire-embedded semiconductor device. Conventionally, a controller chip for controlling the operation of a semiconductor device was disposed at the top of the stacked semiconductor elements. In order to realize high-speed operation, a package technology for a semiconductor device in which a controller chip is disposed at the lowest stage has been developed. As one form of such a package, a package in which a relatively thick film-type adhesive is used when pressing the second-stage semiconductor device among the semiconductor devices laminated in multiple stages, and the controller chip is embedded in the film-type adhesive, attracts attention. Are collecting. The film adhesive used in such applications is required to have high fluidity capable of filling a level difference caused by irregularities on the surface of the substrate, as well as a controller chip and a wire connecting the circuit pattern to the controller chip. This problem can be solved by using a high-flow adhesive sheet like the adhesive sheet of patent documents 1 and 3.

However, while the adhesive sheets described in Patent Documents 1 and 3 exhibit high fluidity before curing, the resin flowing at the time of embedding the controller chip may contaminate the surrounding circuit. In addition, the adhesive sheet flows due to thermal curing after embedding, resulting in a misalignment of the chip position, or the resin enters the inside of the chip as if a tidal tide falls from the end surface of the embedding chip, and the resin disappears at the end of the chip. A phenomenon called may occur (see Fig. 8). In particular, in order to improve the embedding property in recent years, a thermosetting treatment is often performed under pressure conditions. In this way, when heat is applied under pressure from the outside, the embedding property is improved while the resin is more easily flowed, and the above-described problem is often caused.

An object of the present disclosure is to provide a semiconductor device having excellent connection reliability. Further, it is an object of the present disclosure to provide a dicing die bonding integrated tape provided with a thermosetting resin composition useful for manufacturing a semiconductor device having excellent connection reliability and an adhesive layer made of the same.

In order to develop a package in which the controller chip is embedded in a cured product of a film adhesive, the present inventors have repeatedly conducted intensive studies on selection of a film adhesive resin and adjustment of physical properties. As a result, the present inventors have found that the melt viscosity of the film adhesive is correlated with the circuit contamination at the time of embedding and the sink mark generated in the subsequent thermal process.

The semiconductor device according to the present disclosure includes a substrate, a first semiconductor element disposed on the substrate, and a first semiconductor device that is disposed to cover a region in which the first semiconductor element is disposed, and seals the first semiconductor element. A sealing layer and a second semiconductor element having an area larger than that of the first semiconductor element and disposed so as to cover the surface of the first sealing layer opposite to the substrate side, and the first sealing layer comprised of the thermosetting resin composition. It consists of a cured product, and the melt viscosity at 120°C of the thermosetting resin composition is 2500 to 11500 Pa·s.

In the semiconductor device, a first semiconductor element (eg, a controller chip) is embedded in a cured product of a thermosetting resin composition, and the operation can be accelerated. Since the first sealing layer is a cured product of a thermosetting resin composition having a melt viscosity of 2500 to 11500 Pa·s at 120°C, the voids at the interface with the substrate or the first semiconductor element are sufficiently small, and contamination of the substrate and Since the occurrence of the problem of the sink mark is sufficiently suppressed, excellent connection reliability between the substrate and the first semiconductor element can be achieved.

The semiconductor device according to the present disclosure may further include a circuit pattern formed on the surface of the substrate, and a first wire electrically connecting the first semiconductor element and the circuit pattern. The semiconductor device according to the present disclosure may further include a second wire for electrically connecting the second semiconductor element and the circuit pattern, and a second sealing layer sealing the second semiconductor element and the second wire. The semiconductor device according to the present disclosure may further include a third semiconductor element stacked on the second semiconductor element.

The thermosetting resin composition constituting the film adhesive contains a low molecular weight component (such as an epoxy resin) having a molecular weight of 10 to 1,000, and a high molecular weight component (such as acrylic rubber) having a molecular weight of 100,000 to 1 million, and the content of the low molecular weight component M1 is 23 to 35 parts by mass based on 100 parts by mass of the resin component contained in the thermosetting resin composition, and content M2 of the high molecular weight component is 25 to 45 based on 100 parts by mass of the resin component contained in the thermosetting resin composition. It is preferable that it is a mass part. By using the thermosetting resin composition of such a composition, the low molecular weight component contributes to excellent embedding property, and on the other hand, the high molecular weight component contributes to suppression of the problem caused by excessive flow. In the thermosetting resin composition, it is preferable that the total amount (M1+M2) of the low molecular weight component and the high molecular weight component is 54 to 76 parts by mass per 100 parts by mass of the resin component contained in the thermosetting resin composition.

Here, the molecular weight (weight average molecular weight) of the resin component contained in the thermosetting resin composition is measured by gel permeation chromatography (GPC), and means a value converted using a calibration curve using standard polystyrene.

When a substrate having a circuit pattern on its surface is used, the semiconductor device according to the present disclosure may further include a first wire electrically connecting the first semiconductor element and the circuit pattern, and the second semiconductor element and A second wire for electrically connecting the circuit pattern and a second sealing layer for sealing the second semiconductor element and the second wire may be further provided.

The thermosetting resin composition according to the present disclosure undergoes a curing treatment for heating the thermosetting resin composition, and a semiconductor device including a step in which at least one of the wires and at least one of the semiconductor elements are embedded in the thermosetting resin composition after the curing treatment. As used in the manufacturing process, the melt viscosity of the thermosetting resin composition at 120° C. is 2500 to 11500 Pa·s. According to the thermosetting resin composition, in addition to having fluidity to embed semiconductor elements, etc., it is caused by contamination of peripheral circuits during embedding and excessive flow of resin in subsequent thermal processes (thermosetting treatment of thermosetting resin composition). You can sufficiently suppress the problem that you do.

The dicing die-bonding integral tape according to the present disclosure includes an adhesive layer and an adhesive layer made of the thermosetting resin composition.

According to the present disclosure, in addition to providing a semiconductor device having excellent connection reliability, a dicing die-bonding integrated tape provided with a thermosetting resin composition used in its manufacture and an adhesive layer made of the same is provided. This thermosetting resin composition has excellent embedding ability to embed at least one of semiconductor elements such as controller chips and wires, and is caused by contamination of peripheral circuits during embedding and excessive flow of resin in subsequent thermal processes. You can sufficiently suppress the problem that you do.

1 is a cross-sectional view schematically showing an example of a semiconductor device.
2 is a cross-sectional view schematically illustrating an example of a laminate comprising a film adhesive and a second semiconductor element.
3 is a cross-sectional view schematically illustrating a process of manufacturing the semiconductor device shown in FIG. 1.
4 is a cross-sectional view schematically showing a process of manufacturing the semiconductor device shown in FIG. 1.
5 is a cross-sectional view schematically showing a process of manufacturing the semiconductor device shown in FIG. 1.
6 is a cross-sectional view schematically showing a process of manufacturing the semiconductor device shown in FIG. 1.
7(a) to 7(e) are cross-sectional views schematically showing a process of manufacturing a laminate comprising a film adhesive and a second semiconductor element.
Fig. 8(a) is a photograph showing a cross section of a structure in which a phenomenon called "sink mark" has not occurred, and Fig. 8(b) is a cross section of a structure with a "sink mark" (sink mark depth: 140 µm) This is a picture shown.
FIG. 9(a) is a cross-sectional view schematically showing a structure for evaluating the occurrence of voids, FIG. 9(b) is a photograph of the structure without voids, and FIG. 9(c) is a structure with voids It's a picture.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or corresponding portions are denoted by the same reference numerals, and duplicate descriptions are omitted. In addition, the positional relationship, such as top, bottom, left, right, etc. is assumed to be based on the positional relationship shown in a figure, unless otherwise defined. Moreover, the dimensional ratios in the drawings are not limited to the ratios shown. In addition, the description of "(meth)acryl" in this specification means "acrylic" and "methacryl" corresponding to it.

<Semiconductor device>

1 is a cross-sectional view schematically showing a semiconductor device according to the present embodiment. The semiconductor device 100 shown in this figure includes a first semiconductor element Wa that seals the substrate 10, the first semiconductor element Wa disposed on the surface of the substrate 10, and the first semiconductor element Wa. A sealing layer 20, a second semiconductor element Wb disposed above the first semiconductor element Wa, and a second sealing layer 40 sealing the second semiconductor element Wb are provided.

The substrate 10 has circuit patterns 10a and 10b on its surface. From the viewpoint of suppressing the warpage of the semiconductor device 100, the thickness of the substrate 10 is, for example, 90 to 180 µm, and may be 90 to 140 µm. Further, the substrate 10 may be an organic substrate or a metal substrate such as a lead frame.

In this embodiment, the first semiconductor element Wa is a controller chip for driving the semiconductor device 100. The first semiconductor element Wa is bonded to the circuit pattern 10a via an adhesive 15, and is connected to the circuit pattern 10b via the first wire 11. The shape of the first semiconductor element Wa in plan view is, for example, a rectangle (square or rectangle). The length of one side of the first semiconductor element Wa is, for example, 5 mm or less, and may be 2 to 4 mm or 1 to 4 mm. The thickness of the first semiconductor element Wa is, for example, 10 to 150 µm, and may be 20 to 100 µm.

The second semiconductor element Wb has an area larger than that of the first semiconductor element Wa. The second semiconductor element Wb is mounted on the substrate 10 through the first sealing layer 20 so that the entire first semiconductor element Wa and a part of the circuit pattern 10b are covered. The shape of the second semiconductor element Wb in plan view is, for example, a rectangle (square or rectangle). The length of one side of the second semiconductor element Wb is, for example, 20 mm or less, and may be 4 to 20 mm or 4 to 12 mm. The thickness of the second semiconductor element Wb is, for example, 10 to 170 µm, and may be 20 to 120 µm. The second semiconductor element Wb is connected to the circuit pattern 10b via the second wire 12 and is sealed by the sealing layer 25.

The first sealing layer 20 is made of a cured product of a film adhesive 20P (see Fig. 2). In addition, as shown in FIG. 2, the film adhesive 20P and the 2nd semiconductor element Wb are substantially the same size. The laminated body 30 shown in FIG. 2 consists of the film adhesive 20P and the 2nd semiconductor element Wb, and is also called a semiconductor chip with adhesive. The laminated body 30 is produced by going through a dicing process and a pickup process as described later (see Fig. 7).

<Method of manufacturing semiconductor device>

A method of manufacturing the semiconductor device 100 will be described. First, the structure 50 shown in FIG. 3 is manufactured. That is, the first semiconductor device Wa is disposed on the surface of the substrate 10 through the adhesive 15. After that, the first semiconductor element Wa and the circuit pattern 10b are electrically connected with the first wire 11.

Next, as shown in FIGS. 3 and 4, the film adhesive 20P of the laminate 30 prepared separately is pressed against the substrate 10. Accordingly, the first semiconductor element Wa and the first wire 11 are embedded in the film adhesive 20P. The thickness of the film adhesive 20P may be appropriately set according to the thickness of the first semiconductor element Wa, for example, in the range of 20 to 200 µm, and may be 30 to 200 µm or 40 to 150 µm. By setting the thickness of the film adhesive 20P to the above range, it is possible to sufficiently secure a distance (distance G in FIG. 5) between the first semiconductor element Wa and the second semiconductor element Wb. The distance G is preferably 50 μm or more, for example, and may be 50 to 75 μm or 50 to 80 μm.

With respect to the substrate 10 of the film adhesive 20P, it is preferable to perform compression bonding for 0.5 to 3.0 seconds under conditions of, for example, 80 to 180°C and 0.01 to 0.50 MPa.

Next, the film adhesive 20P is cured by heating. It is preferable to perform this hardening treatment over 5 minutes or more under conditions of 60-175 degreeC and 0.01-1.0 MPa, for example. Accordingly, the first semiconductor element Wa is sealed with the cured product (first sealing layer 20) of the film adhesive 20P (see Fig. 6). The curing treatment of the film adhesive 20P may be performed in a pressurized atmosphere from the viewpoint of reducing voids. After the second semiconductor element Wb and the circuit pattern 10b are electrically connected with the second wire 12, the second semiconductor element Wb is sealed by the second sealing layer 40 to thereby the semiconductor device 100 ) Is completed (see Fig. 1).

<Method of manufacturing semiconductor chip with adhesive>

An example of a method of manufacturing the laminate 30 (semiconductor chip with adhesive) shown in FIG. 2 will be described with reference to FIGS. 7A to 7E. First, a dicing die bonding integrated tape 8 (hereinafter, referred to as "tape 8" in some cases) is placed in a predetermined apparatus (not shown). The tape 8 includes a base layer 1, an adhesive layer 2, and an adhesive layer 20A in this order. The base layer 1 is, for example, a polyethylene terephthalate film (PET film). The semiconductor wafer W is, for example, a thin semiconductor wafer having a thickness of 10 to 100 µm. The semiconductor wafer W may be single crystal silicon, polycrystalline silicon, various ceramics, or compound semiconductors such as gallium arsenide.

As shown in Figs. 7(a) and 7(b), a tape 8 is affixed to one side of the semiconductor wafer W so that the adhesive layer 20A contacts. This step is preferably carried out under a temperature condition of 50 to 100°C, more preferably 60 to 80°C. When the temperature is 50°C or higher, good adhesion of the semiconductor wafer W to the adhesive layer 20A can be obtained, and when the temperature is 100°C or less, excessive flow of the adhesive layer 20A in this step is suppressed.

As shown in Fig. 7(c), the semiconductor wafer W, the adhesive layer 2, and the adhesive layer 20A are diced. Accordingly, the semiconductor wafer W is divided into pieces to form a semiconductor element Wb. The adhesive layer 20A is also divided into pieces to form a film adhesive 20P. As a dicing method, a method using a rotating blade or a laser is exemplified. Further, prior to dicing the semiconductor wafer W, the semiconductor wafer W may be ground to form a thin film.

Next, when the adhesive layer 2 is, for example, a UV curable type, as shown in Fig. 7(d), the adhesive layer 2 is cured by irradiating the adhesive layer 2 with ultraviolet rays to cure the adhesive layer 2 And the adhesive force between the film adhesive 20P is lowered. After UV irradiation, as shown in Fig. 7(e), by expanding the base layer 1 under room temperature or cooling conditions, the semiconductor elements Wa are lifted up with a needle 42 while spaced apart from each other, and the adhesive layer 2 The film adhesive 20P of the laminated body 30 is peeled off from, and the laminated body 30 is sucked by the suction collet 44 and picked up. The laminated body 30 obtained in this way is provided for manufacture of the structure 50 shown in FIG.

<Thermosetting resin composition>

The thermosetting resin composition constituting the film adhesive 20P will be described. In addition, the film adhesive 20P is obtained by separating the adhesive layer 20A, and both are made of the same thermosetting resin composition. This thermosetting resin composition can be in a state of a completely cured product (C stage) by, for example, a semi-cured (B stage) state and then cured.

It is preferable that the thermosetting resin composition contains the following components.

(a) Thermosetting resin (hereinafter, simply referred to as "component (a)" in some cases.)

(b) High molecular weight component (hereinafter, simply referred to as "(b) component" in some cases.)

(c) Inorganic filler (hereinafter, simply referred to as "component (c)" in some cases.)

In addition, in this embodiment, when (a) thermosetting resin contains an epoxy resin, epoxy resin (hereinafter, simply referred to as "component (a1)" in some cases) corresponds to "low molecular weight component". In this case, (a) the thermosetting resin preferably contains a phenol resin (hereinafter, simply referred to as "component (a2)" in some cases) that can serve as a curing agent for an epoxy resin.

The thermosetting resin composition may further contain the following components.

(d) Coupling agent (hereinafter, simply referred to as "component (d)" in some cases.)

(e) Hardening accelerator (hereinafter, simply referred to as "(e) component" in some cases.)

The thermosetting resin composition preferably contains both a low molecular weight component (component (a1)) having a molecular weight of 10 to 1000 and a high molecular weight component (component (b)) having a molecular weight of 100,000 to 1,000,000. By using these components together, the low molecular weight component contributes to excellent embedding property, and on the other hand, the high molecular weight component contributes to suppression of the problem caused by excessive flow.

The content M1 of the low molecular weight component is preferably 23 to 35 parts by mass, and more preferably 25 to 35 parts by mass with respect to 100 parts by mass of the resin component contained in the thermosetting resin composition. When the content M1 of the low molecular weight component is 23 parts by mass or more, it is easy to achieve excellent embedding properties, and on the other hand, when the content M1 is 35 parts by mass or less, the effect that excellent pick-up properties are easily achieved is exhibited. Further, the softening point of the low molecular weight component is preferably 50°C or less, and may be, for example, 10 to 30°C.

The content M2 of the high molecular weight component is preferably 25 to 45 parts by mass, and more preferably 30 to 40 parts by mass with respect to 100 parts by mass of the resin component contained in the thermosetting resin composition. When the content M2 of the high molecular weight component is 25 parts by mass or more, it is easy to suppress problems caused by excessive flow (contamination of the substrate, sink marks, warping, etc.), and on the other hand, it is 45 parts by mass or less, thereby achieving excellent embedding The effect that it is easy to do is exhibited. In addition, it is preferable that the softening point of the high molecular weight component exceeds 50°C and is 100°C or less.

With respect to 100 parts by mass of the resin component contained in the thermosetting resin composition, the total amount (M1 + M2) of the low molecular weight component and the high molecular weight component is preferably 54 to 76 parts by mass, more preferably 55 to 75 parts by mass. When this total amount is 54 parts by mass or more, the effect of using these components together tends to be sufficiently exhibited, and on the other hand, when the total amount is 76 parts by mass or less, the effect that excellent pick-up properties are easily achieved is exhibited. Moreover, it is a resin component contained in a thermosetting resin composition, and as a thing other than a low molecular weight component and a high molecular weight component, the thermosetting resin etc. which are mainly 1001-99,000 molecular weights are mentioned.

The melt viscosity at 120° C. of the thermosetting resin composition is 2500 to 11500 Pa·s from the viewpoint of connection reliability. When this melt viscosity is 2500 Pa·s or more, it is possible to sufficiently suppress contamination of the substrate 10 and the occurrence of sink mark problems during the pressing treatment or the like. For example, if there is a region (sink mark) between the second semiconductor element Wb and the substrate 10 in which the cured product of the thermosetting resin composition does not exist, the sealing material for the second sealing layer 40 penetrates into the region, Accordingly, the problem that the second semiconductor element Wb is easily peeled is likely to occur. When the melt viscosity of the thermosetting resin composition at 120° C. is 11500 Pa·s or less, the voids at the interface with the substrate 10 or the first semiconductor element Wa can be sufficiently reduced. This melt viscosity is preferably 5000 to 11000 Pa·s, more preferably 5000 to 10000 Pa·s, and still more preferably 5000 to 9000 Pa·s. In addition, the melt viscosity refers to a measured value when measured while increasing the temperature at a heating rate of 5°C/min while applying 5% strain to a thermosetting resin composition molded into a film using ARES (manufactured by TA Instruments).

From the viewpoint of connection reliability, the melt viscosity of the thermosetting resin composition at 100°C is preferably 3500 to 13500 Pa·s. When this melt viscosity is 3500 Pa·s or more, it is possible to sufficiently suppress contamination of the substrate 10 and the occurrence of sink mark problems during the pressing treatment or the like. On the other hand, when this melt viscosity is 13500 Pa·s or less, the voids at the interface with the substrate 10 or the first semiconductor element Wa can be sufficiently reduced. This melt viscosity is preferably 5500 to 10500 Pa·s. In order to make the melt viscosity of the thermosetting resin composition at 100°C and 120°C within the above range, the amounts of (a) thermosetting resin, (b) high molecular weight component, and (c) inorganic filler may be appropriately adjusted.

9(a) shows a transparent substrate 10, a first semiconductor element Wa thereon, a first sealing layer 20 (a cured product of the film adhesive 20P), and a second thereon. It is a structure including the semiconductor element Wb. 9(b) and 9(c) are photographs taken from the back side of the transparent substrate 10 (in the direction of the arrow in FIG. 9(a)). In the structure shown in Fig. 9(b), the embedding property of the film adhesive was sufficient and no voids occurred. In contrast, in the structure shown in Fig. 9(c), the embedding property of the film adhesive was insufficient, and voids V were generated.

The storage modulus at 180°C of the cured product (C stage) of the thermosetting resin composition is preferably 10 MPa or more, more preferably 25 MPa or more, and may be 50 MPa or more or 100 MPa or more from the viewpoint of connection reliability. Further, the upper limit of this storage modulus is, for example, 600 MPa, and may be 500 MPa. The storage modulus of the cured product of the thermosetting resin composition at 180°C can be measured using a dynamic viscoelastic device using a sample obtained by curing a film adhesive under a temperature condition of 175°C.

<(a) thermosetting resin>

The component (a1) can be used without particular limitation as long as it has an epoxy group in its molecule. As the component (a1), for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F no Rock-type epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, stilbene-type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenolphenolmethane-type epoxy resin, biphenyl-type epoxy resin, xylene-type epoxy Diglycidyl ether compounds of polycyclic aromatics such as resin, biphenylaralkyl type epoxy resin, naphthalene type epoxy resin, polyfunctional phenols, and anthracene. These may be used alone or in combination of two or more. Among these, the component (a1) may be a cresol novolak type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol A type epoxy resin from the viewpoint of heat resistance.

The epoxy equivalent of the component (a1) may be 90 to 300 g/eq, 110 to 290 g/eq, or 130 to 280 g/eq. When the epoxy equivalent of the component (a1) is in such a range, there is a tendency that fluidity can be secured while maintaining the bulk strength of the film adhesive.

The content of the component (a1) may be 5 to 50 parts by mass, 10 to 40 parts by mass, or 20 to 30 parts by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c). When the content of the component (a1) is 5 parts by mass or more, there is a tendency for the embedding property of the film adhesive to be more favorable. When the content of the component (a1) is 50 parts by mass or less, there is a tendency that the occurrence of bleed can be more suppressed.

The component (a2) can be used without particular limitation as long as it has a phenolic hydroxyl group in its molecule. (a2) As the component, for example, 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 phenols such as novolak-type phenol resin, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenol, etc. obtained by condensing or co-condensing a compound having an aldehyde group such as formaldehyde and/or Phenol aralkyl resin, naphthol aralkyl resin, and the like synthesized from naphthol and dimethoxyparaxylene or bis(methoxymethyl)biphenyl. These may be used alone or in combination of two or more. Among these, the component (a2) may be a phenol aralkyl resin, a naphthol aralkyl resin, or a novolac-type phenol resin from the viewpoint of hygroscopicity and heat resistance.

The hydroxyl group equivalent of the component (a2) may be 80 to 250 g/eq, 90 to 200 g/eq, or 100 to 180 g/eq. When the hydroxyl equivalent of the component (a2) is in such a range, there is a tendency that the adhesive force can be maintained higher while maintaining the fluidity of the film adhesive.

The softening point of the component (a2) may be 50 to 140°C, 55 to 120°C, or 60 to 100°C.

The content of the component (a2) may be 5 to 50 parts by mass, 10 to 40 parts by mass, or 20 to 30 parts by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c). When the content of the component (a2) is 5 parts by mass or more, there is a tendency that better curability can be obtained. When the content of the component (a2) is 50 parts by mass or less, there is a tendency for the embedding property of the film adhesive to be more favorable.

The ratio of the epoxy equivalent of the component (a1) and the equivalent of the hydroxyl group of the component (a2) (the epoxy equivalent of the component (a1) / the equivalent of the hydroxyl group of the component (a2)) is from the viewpoint of curability, from 0.30/0.70 to 0.70/0.30, 0.35 /0.65 to 0.65/0.35, 0.40/0.60 to 0.60/0.40 or 0.45/0.55 to 0.55/0.45 may be used. When the above equivalent ratio is 0.30/0.70 or more, there is a tendency that more sufficient curability can be obtained. When the above equivalent ratio is 0.70/0.30 or less, it is possible to prevent the viscosity from becoming too high, so that more sufficient fluidity can be obtained.

<(b) high molecular weight component>

It is preferable that the component (b) has a glass transition temperature (Tg) of 50°C or less.

Examples of the component (b) include acrylic resins, polyester resins, polyamide resins, polyimide resins, silicone resins, butadiene resins, acrylonitrile resins, and modified products thereof.

The component (b) may contain an acrylic resin from the viewpoint of fluidity. Here, the acrylic resin means a polymer containing a structural unit derived from a (meth)acrylic acid ester. The acrylic resin is preferably a polymer containing, as a structural unit, 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. Further, the acrylic resin may be an acrylic rubber such as a copolymer of (meth)acrylic acid ester and acrylnitrile.

The glass transition temperature (Tg) of the acrylic resin may be -50 to 50°C or -30 to 30°C. When the Tg of the acrylic resin is -50° C. or higher, there is a tendency that the flexibility of the adhesive composition can be prevented from becoming too high. Accordingly, it becomes easy to cut the film adhesive during wafer dicing, thereby preventing the occurrence of burrs. When the Tg of the acrylic resin is 50° C. or less, there is a tendency that the decrease in flexibility of the adhesive composition can be suppressed. Thereby, when the film adhesive is attached to the wafer, it tends to be easy to sufficiently fill the void. In addition, chipping during dicing due to a decrease in the adhesion of the wafer can be prevented. Here, the glass transition temperature (Tg) means a value measured using a DSC (thermal differential scanning calorimeter) (for example, "Thermo Plus 2" manufactured by Co., Ltd.).

The weight average molecular weight (Mw) of the acrylic resin may be 100,000 to 3 million or 500,000 to 2 million. When the Mw of the acrylic resin is in such a range, it is possible to appropriately control the film formability, the strength in the film form, flexibility, tackiness, and the like, and the reflow property is excellent, and the embedding property can be improved. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve using standard polystyrene.

Commercially available products of acrylic resin include, for example, SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, HTR-860P-3CSP, HTR-860P-3CSP-3DB (all are Nagase Chemtex Co., Ltd. Manufacturing).

The content of the component (b) may be 5 to 70 parts by mass, 10 to 50 parts by mass, or 15 to 30 parts by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c). When the content of the component (b) is 5 parts by mass or more, the flowability control during molding and the handling at high temperatures can be further improved. When the content of the component (b) is 70 parts by mass or less, the embedding property can be further improved.

<(c) inorganic filler>

Examples of the component (c) include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, silica, and the like. . These may be used alone or in combination of two or more. Among these, the component (c) may be silica from the viewpoint of compatibility with resin.

The average particle diameter of the component (c) may be 0.005 to 1 µm or 0.05 to 0.5 µm from the viewpoint of improving adhesion. Here, the average particle diameter means a value obtained by converting from the BET specific surface area.

The content of the component (c) may be 5 to 50 parts by mass, 15 to 45 parts by mass, or 25 to 40 parts by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c). When the content of the component (c) is 5 parts by mass or more, the fluidity of the film adhesive tends to be more improved. When the content of the component (c) is 50 parts by mass or less, the dicing property of the film adhesive tends to be more favorable.

<(d) coupling agent>

The component (d) may be a silane coupling agent. Examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. And the like. These may be used alone or in combination of two or more.

The content of the component (d) may be 0.01 to 5 parts by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c).

<(e) hardening accelerator>

The component (e) is not particularly limited, and those generally used may be used. Examples of the component (e) include imidazoles and derivatives thereof, organophosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. Among these, from the viewpoint of reactivity, the component (e) may be imidazoles and derivatives thereof.

Examples of imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, etc. Can be mentioned. These may be used alone or in combination of two or more.

The content of the component (e) may be 0.01 to 1 part by mass based on 100 parts by mass of the total mass of the component (a), the component (b) and the component (c).

[Dicing die bonding integrated tape and its manufacturing method]

The dicing die bonding integrated tape 8 shown in Fig. 7(a) and its manufacturing method will be described. The manufacturing method of the tape 8 includes a step of applying a varnish of an adhesive composition containing a solvent onto a base film (not shown), and forming the adhesive layer 20A by heating and drying the applied varnish at 50 to 150°C. Including the process.

The varnish of the adhesive composition can be prepared, for example, by mixing or kneading components (a) to (c), and if necessary, components (d) and (e) in a solvent. Mixing or kneading can be performed by using a conventional stirrer, a raker, a dispersing machine such as a three roll or a ball mill, and appropriately combining them.

The solvent for producing the varnish is not limited as long as it is capable of uniformly dissolving, kneading or dispersing the respective components, and a conventionally known solvent may be used. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dimethylformamide, dimethylacetamide, Nmethylpyrrolidone, toluene, xylene, and the like. It is preferable to use methyl ethyl ketone, cyclohexanone, or the like from the viewpoint of fast drying speed and low price.

There is no restriction|limiting in particular as a base film, For example, a polyester film, a polypropylene film (OPP film, etc.), a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyether naphthalate film, a methylpentene film, etc. are mentioned. .

As a method of applying the varnish to the base film, a known method can be used, for example, a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, a curtain coating method, and the like. The conditions for heating and drying are not particularly limited as long as the solvent used is sufficiently evaporated, but may be performed by heating at 50 to 150°C for 1 to 30 minutes, for example. Heat drying may be performed by raising the temperature step by step at a temperature within the range of 50 to 150°C. The laminated film of the base film and the adhesive layer 20A can be obtained by volatilizing the solvent contained in the varnish by heat drying.

The tape 8 can be obtained by bonding the laminated film obtained as described above and a dicing tape (a laminate of the base layer 1 and the adhesive layer 2). As the base material layer 1, plastic films, such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film, etc. are mentioned, for example. Further, the substrate layer 1 may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment as necessary. The adhesive layer 2 may be of a UV curable type or a pressure sensitive type. The tape 8 may further include a protective film (not shown) covering the adhesive layer 2.

As mentioned above, although the embodiment of this disclosure was demonstrated in detail, this invention is not limited to the said embodiment. For example, in the above embodiment, a package in which two semiconductor elements Wa and Wb are stacked is illustrated, but a third semiconductor element may be stacked above the second semiconductor element Wb, and further One or a plurality of semiconductor elements may be stacked.

Example

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

(Examples 1 to 6 and Comparative Examples 1 and 2)

Varnishes (6 types in total) containing the components shown in Table 1 and Table 2 were prepared as follows. That is, cyclohexanone was added and stirred to a composition containing an epoxy resin as a thermosetting resin, a phenol resin, and an inorganic filler. After adding and stirring acrylic rubber as a high molecular weight component to this, a coupling agent and a curing accelerator were further added and stirred until each component became sufficiently uniform to obtain a varnish.

The components listed in Table 1 and Table 2 are as follows.

(Epoxy resin)

YDF-8170C (brand name): manufactured by Toto Kasei Co., Ltd., bisphenol F type epoxy resin, epoxy equivalent 159, liquid at room temperature, softening point 10 to 30°C, molecular weight 100 to 1000 (low molecular weight component)

YDCN-700-10 (brand name): manufactured by Totokasei Co., Ltd., cresol novolak type epoxy resin, epoxy equivalent 210, softening point 75-85℃), molecular weight exceeding 1000

(Phenolic resin)

Mirex XLC-LL (brand name): manufactured by Mitsui Chemicals Co., Ltd., phenolic resin, hydroxyl equivalent weight 175, softening point 77℃, molecular weight exceeding 1000

(Acrylic rubber)

HTR-860P-3CSP: manufactured by Nagase Chemtex Co., Ltd., a weight average molecular weight of 800,000 (high molecular weight component)

(Inorganic filler)

SC2050-HLG (brand name): manufactured by Admatex Co., Ltd., silica filler dispersion, average particle diameter 0.50 µm

(Hardening accelerator)

Qazole 2PZ-CN (trade name): manufactured by Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole

The varnish containing the above components was filtered through a 100 mesh filter and vacuum defoamed. The varnish after vacuum defoaming was applied onto a polyethylenerate (PET) film (38 µm in thickness) subjected to a release treatment. The applied varnish was heated and dried at 90°C for 5 minutes and then at 140°C for 5 minutes in two steps. In this way, on the PET film as a base film, an adhesive sheet provided with a film adhesive (60 µm in thickness) in a B stage state was obtained.

(Measurement of melt viscosity of film adhesive)

The melt viscosity at 100°C and 120°C of the film adhesive was measured by the following method. That is, by laminating five film adhesives having a thickness of 60 µm, the thickness was set to 300 µm, and a sample for measurement was obtained by punching this to a size of 10 mm×10 mm. A circular aluminum plate jig having a diameter of 8 mm was set in a dynamic viscoelastic device ARES (manufactured by TA Instruments), and the sample was set thereto. Thereafter, it was measured while raising the temperature to 130°C at a temperature increase rate of 5°C/min while applying 5% strain at 35°C, and the values of the melt viscosity at 100°C and 120°C were recorded. The results are shown in Tables 1 and 2.

(Measurement of elastic modulus of cured product of film adhesive)

The elastic modulus at 180° C. of the cured product of the film adhesive (cured under a temperature condition of 175° C.) was measured. For the measurement, a dynamic viscoelastic device (product name: Rheogel-E4000, manufactured by UBM Co., Ltd.) was used, a tensile load was applied to the sample, and the temperature was raised to 300°C at a temperature increase rate of 10 Hz and 3°C/min. The elastic modulus at °C was measured. The results are shown in Tables 1 and 2.

<Evaluation of film adhesive>

About the film adhesive, the following items were evaluated.

[Reclamation]

The embedding property of the film adhesive was evaluated by the following method.

(Preparation of a laminate consisting of a first semiconductor element and a film adhesive)

A dicing die-bonding integral film HR-9004-10 (manufactured by Hitachi Kasei Co., Ltd., an adhesive layer thickness of 10 μm, an adhesive layer thickness of 110 μm) was attached to a semiconductor wafer (diameter: 8 inches, thickness: 50 μm). By dicing this, a first laminate made of a first semiconductor element (controller chip, size: 3.0 mm x 3.0 mm) and a film adhesive was obtained.

(Production of a laminate consisting of a second semiconductor element and a film adhesive)

A dicing die-bonding integrated film including each film adhesive (120 µm thick) and an adhesive film for dicing according to Examples and Comparative Examples was prepared. This was attached to a semiconductor wafer (diameter: 8 inches, thickness: 30 µm). By dicing this, a second laminate made of a second semiconductor element (size: 7.5 mm x 7.5 mm) and a film adhesive was obtained.

(Adhesion of the first and second semiconductor elements)

A substrate (surface irregularities: up to 6 µm) for pressing the first and second semiconductor elements was prepared. The first semiconductor element was press-bonded to the substrate through a film adhesive under conditions of 120°C, 0.20 MPa for 2 seconds, and then heated at 120°C for 2 hours to semi-cure the film adhesive.

Next, the second semiconductor element was press-bonded under the conditions of 120°C, 0.20 MPa, and 2 seconds through a film adhesive to be evaluated so as to cover the first semiconductor element. At this time, the position was aligned so that the center positions of the first and second semiconductor elements that had been crimped previously matched when viewed from the top.

The structure obtained as described above was put into a pressurized oven, heated from 35° C. to 140° C. at a rate of 3° C./min, and heated at 140° C. for 30 minutes. The structure after heat treatment was analyzed with an ultrasonic imaging device SAT (manufactured by Hitachi Power Solutions, part number FS200II, probe: 25 MHz) to confirm embedding. It evaluated based on the following criteria. The results are shown in Tables 3 and 4.

A: The area ratio of voids in a predetermined cross section is less than 5%.

B: The area ratio of voids in a predetermined cross section is 5% or more.

[Package contamination and presence or absence of sink mark]

The presence or absence of contamination and occurrence of sink marks were confirmed by observing the upper and side surfaces of the structure provided for the evaluation of the embedding property under a microscope. For the sample in which the sink mark occurred, the depth of the sink mark (start point: the end of the second semiconductor element) was measured. The results are shown in Tables 3 and 4.

[Measurement of adhesive strength]

The die share strength (adhesion strength) of the cured product of the film adhesive was measured by the following method. First, each of the film adhesives (thickness 120 µm) according to Examples and Comparative Examples was applied to a semiconductor wafer (thickness 400 µm) at 70°C. By dicing this, a laminate composed of a semiconductor element (size: 5 mm x 5 mm) and a film adhesive was obtained. On the other hand, a substrate coated with solder resist ink (AUS308) on the surface was prepared. The semiconductor element was pressed onto this surface through a film adhesive under conditions of 120°C, 0.1 MPa, and 5 seconds. Thereafter, this was subjected to a heat treatment at 110° C. for 1 hour, and then heated at 170° C. for 3 hours to cure the film adhesive to obtain a sample for measurement. This sample was allowed to stand for 168 hours at 85°C and 60 RH%. Thereafter, the sample was allowed to stand for 30 minutes under the conditions of 25°C and 50% RH, and then the die-shear strength was measured at 250°C, and this was used as the adhesive strength. For the measurement of the die share strength, a universal bond tester series 4000 manufactured by Dage Corporation was used. The results are shown in Tables 3 and 4.

[Evaluation of reflow resistance]

The reflow property of the film adhesive was evaluated by the following method. First, a structure having the same formula as the structure used for evaluating the embedding property was produced. A package for evaluation was obtained by sealing the second semiconductor element of the structure with a mold sealing material (manufactured by Hitachi Kasei Co., Ltd., brand name "CEL-9750 ZHF10). In addition, the resin sealing conditions were 175°C/6.7 MPa/90 seconds, and the curing conditions were 175°C and 5 hours.

24 packages were prepared, and these were exposed to the environment specified by JEDEC (level 3, 30° C., 60 RH%, 192 hours) to give moisture absorption. Subsequently, the moisture-absorbed package was passed through an IR reflow furnace (260°C, maximum temperature of 265°C) three times. It evaluated based on the following criteria. The results are shown in Tables 3 and 4.

A: Damage of the package, change in thickness, peeling at the interface between the film adhesive and the semiconductor element, etc. were not observed in one of the 24 packages.

B: At least one of 24 packages was observed, such as breakage of the package, change in thickness, and peeling at the interface between the film adhesive and the semiconductor element.

As is clear from the results shown in Tables 3 and 4, the film adhesives of Examples 1 to 5 are superior to the film adhesives of Comparative Examples 1 to 3 after treatment with a pressure oven, and In addition, it was confirmed that contamination of the package and occurrence of sink marks can be suppressed.

According to the present disclosure, while having fluidity capable of embedding at least one of a semiconductor element such as a controller chip and a wire, problems caused by contamination of peripheral circuits during embedding and excessive flow of resin in subsequent thermal processes are sufficiently solved. A thermosetting resin composition that can be suppressed, and a semiconductor device manufactured using the same, and a method for manufacturing the same are provided.

2: adhesive layer, 8: dicing die bonding integral tape, 10: substrate, 11: first wire, 12: second wire, 10a, 10b: circuit pattern, 20: first sealing layer (cured product of film adhesive ), 20A: adhesive layer, 20P: film adhesive, 40: second sealing layer, 100: semiconductor device, Wa: first semiconductor element, Wb: second semiconductor element

Claims (10)

The substrate,
A first semiconductor device disposed on the substrate,
A first sealing layer disposed so as to cover a region of the substrate in which the first semiconductor element is disposed, and sealing the first semiconductor element;
A second semiconductor element disposed so as to cover a surface of the first sealing layer opposite to the substrate side, and having a larger area than the first semiconductor element
And,
A semiconductor device in which the first sealing layer is made of a cured product of a thermosetting resin composition, and a melt viscosity of the thermosetting resin composition at 120°C is 2500 to 11500 Pa·s. The method of claim 1,
The thermosetting resin composition contains a low molecular weight component with a molecular weight of 10 to 1000 and a high molecular weight component with a molecular weight of 100,000 to 1 million,
The content M1 of the low molecular weight component is 23 to 35 parts by mass with respect to 100 parts by mass of the resin component contained in the thermosetting resin composition,
A semiconductor device in which content M2 of the high molecular weight component is 25 to 45 parts by mass per 100 parts by mass of the resin component contained in the thermosetting resin composition. The semiconductor device according to claim 2, wherein the total amount of the low molecular weight component and the high molecular weight component is 54 to 76 parts by mass per 100 parts by mass of the resin component contained in the thermosetting resin composition. The method according to any one of claims 1 to 3,
A circuit pattern formed on the surface of the substrate,
A first wire electrically connecting the first semiconductor element and the circuit pattern
A semiconductor device further comprising a. The method of claim 4,
A second wire electrically connecting the second semiconductor element and the circuit pattern,
A second sealing layer sealing the second semiconductor element and the second wire
The semiconductor device further comprising. The semiconductor device according to any one of claims 1 to 5, further comprising a third semiconductor element stacked on the second semiconductor element. As a thermosetting resin composition used in a semiconductor device manufacturing process,
The manufacturing process includes a step in which at least a part of the wire and at least one of the semiconductor element are embedded in the thermosetting resin composition after the curing treatment through a curing treatment for heating the thermosetting resin composition,
The thermosetting resin composition has a melt viscosity of 2500 to 11500 Pa·s at 120°C of the thermosetting resin composition. The method of claim 7,
A low molecular weight component having a molecular weight of 10 to 1000, and
High molecular weight component with molecular weight of 100,000 to 1 million
Including,
The content M1 of the low molecular weight component is 23 to 35 parts by mass with respect to 100 parts by mass of the resin component contained in the thermosetting resin composition,
The thermosetting resin composition in which the content M2 of the high molecular weight component is 25 to 45 parts by mass based on 100 parts by mass of the resin component contained in the thermosetting resin composition. The thermosetting resin composition according to claim 8, wherein the total amount of the low molecular weight component and the high molecular weight component is 54 to 76 parts by mass based on 100 parts by mass of the resin component contained in the thermosetting resin composition. An adhesive layer,
An adhesive layer comprising the thermosetting resin composition according to any one of claims 7 to 9
Dicing die bonding integral tape having a.

Images