JP5924145B2 - Film adhesive, adhesive sheet, and method for manufacturing semiconductor device - Google Patents

Description

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

  Stacked MCP (Multi Chip Package), in which chips are stacked in multiple stages and increased in capacity with the increasing functionality of mobile phones and the like, has become widespread, and film adhesives that are advantageous in the mounting process for mounting semiconductor devices Is widely used as an adhesive for die bonding. An example of a multi-layer stacked package using such a film adhesive is a wire-embedded package. This is a package using a highly fluid film adhesive, and is a package in which a wire is covered with an adhesive by pressing the adhesive onto a chip to which the wire is connected. Such a package is mounted on a memory package or the like for a cellular phone or a portable audio device.

  One of important characteristics required for a semiconductor device such as the stacked MCP is connection reliability. In order to improve connection reliability, development of film adhesives in consideration of characteristics such as heat resistance, moisture resistance, and reflow resistance has been performed. With regard to such a film adhesive, for example, in Patent Document 1, an adhesive sheet having a thickness of 10 to 250 μm containing a resin and a filler containing a high molecular weight component and a thermosetting component mainly composed of an epoxy resin. Has been proposed. Moreover, in patent document 2, the adhesive film containing the mixture containing an epoxy resin and a phenol resin, and an acrylic copolymer is proposed.

  Further, the connection reliability of the semiconductor device depends on whether or not the chip and the support member can be pressure-bonded via the adhesive without generating a gap on the adhesive surface between the adhesive and the support member (semiconductor element or substrate). It is greatly influenced. Therefore, use a high-fluid film adhesive so that the chip and the support member can be pressure-bonded without generating a void, or a film with a low elastic modulus to eliminate the generated void in the sealing process Ingenuity has been made such as using an adhesive.

International Publication WO2005 / 103180 Pamphlet JP 2002-220576 A

  In recent years, in order to achieve higher capacity and higher density of packages, attempts have been made to reduce the thickness of the chip to the utmost limit. When assembling a package using such an ultrathin chip, Problems occur. For example, when a film adhesive is used, the chip with adhesive is peeled off from the dicing tape by being picked up by a tool with a hole called a collet and lifted, and is pressed onto the support member. Here, as the chip becomes thinner, the chip is easily bent in a convex shape due to the suction holes of the collet. As a result, the quality after crimping is lowered, and a gap is generated between the adhesive and the support member. Connection reliability is likely to decrease.

  Such a phenomenon that voids are likely to be generated and the connection reliability is likely to be lowered is remarkable when there is unevenness due to the wire at the end of the chip that is the adherend, as in a wire-embedded package. It has become. For example, the adhesive sheet or the like of Patent Document 1 contains a large amount of epoxy resin or the like for the purpose of achieving high fluidization because the wire is embedded at the time of pressure bonding. For this reason, heat curing proceeds due to heat during the manufacturing process of the semiconductor element, and the elasticity becomes high, so that the film-like adhesive does not deform even under high temperature and high pressure conditions in the sealing process, and voids formed at the time of pressure bonding May eventually disappear.

  On the other hand, although the adhesive film of Patent Document 2 has a low elastic modulus and easily loses voids in the sealing process, it has a high viscosity, so that it may be difficult to sufficiently embed the wire when the adhesive film is pressed.

  In this way, when an ultra-thin chip is pressure-bonded using a conventional film-like adhesive for embedding a wire, a gap is generated when the film-like adhesive is pressure-bonded and hardly disappears thereafter. Reliability may not be obtained.

  In order to solve such a problem, the present inventors can embed a wire at the time of pressure bonding by making the adhesive highly fluidized, and heat (for example, 150 ° C./1) during the manufacturing process of the semiconductor device. The development of a film-like adhesive that can suppress the progress of thermosetting by heating (time) and maintain a low elastic state and can eliminate voids at the time of sealing has been promoted.

  Here, from the viewpoint of maintaining the film adhesive in a low elastic state with respect to the heating during the manufacturing process of the semiconductor device, when the curing rate of the thermosetting component is simply slowed, the heating during the manufacturing process The film adhesive is easily foamed. In this case, the voids increase compared to the pressure bonding, and the voids are not easily lost during sealing, and the connection reliability tends to be lowered. There is also an attempt to improve the processability of the manufacturing process by minimizing heating during the manufacturing process. Therefore, for film adhesives, foaming is suppressed by minimum heating during the manufacturing process, and gaps remain between the adhesive and the support member in the connection between the semiconductor element and the support member. There is a need to suppress and improve connection reliability.

  The present invention has been made in view of the above circumstances, a film adhesive capable of improving connection reliability in the connection between the semiconductor element and the support member, an adhesive sheet using the film adhesive, And it aims at providing the manufacturing method of a semiconductor device.

In order to achieve the above object, the present inventors have conducted extensive research on the selection of resins used for film adhesives and the adjustment of physical properties. Then, the inventors adjusted the content of the thermosetting component, the high molecular weight component having a reactive functional group, and the inorganic filler, and then adjusted the molecular weight of the high molecular weight component, the glass transition temperature, and the crosslinkable functional group. It has been found that the above problem can be solved by adjusting the ratio and combining thermosetting components having different crosslinking densities.

  That is, the film adhesive according to the present invention is (a1) an epoxy resin having a softening point of 85 ° C. or higher and an epoxy equivalent of 500 or higher, and a softening point of 85 ° C. or higher and a hydroxyl group equivalent of 500 or higher. And (a2) an epoxy resin having a softening point of 85 ° C. or higher and an epoxy equivalent of 150 or lower, and a phenol having a softening point of 85 ° C. or higher and a hydroxyl group equivalent of 150 or lower. A thermosetting component comprising at least one of a resin, and (a3) at least one of an epoxy resin and a phenol resin having a softening point of 75 ° C. or less, and (b) a crosslinkable functional group in a monomer ratio of 3 to 15%. A high molecular weight component having a weight average molecular weight of 100,000 to 1,000,000 and a glass transition temperature (Tg) of −50 to 50 ° C., and (c) an inorganic filler And the content of the component (a1) is 10 to 40 parts by mass based on 100 parts by mass of the thermosetting component, and the content of the component (a2) is based on 100 parts by mass of the thermosetting component 5 to 20 parts by mass, the content of the component (a3) is 25 to 55 parts by mass based on 100 parts by mass of the thermosetting component, and the content of the high molecular weight component is based on 100 parts by mass of the thermosetting component 20 to 100 parts by mass, and the inorganic filler content is 10 to 80 parts by mass based on 100 parts by mass of the thermosetting component.

  In the film adhesive according to the present invention, when the semiconductor element and the support member are connected via the adhesive, the film adhesive is highly fluidized. Even when unevenness is formed on the bonding surface, the adhesive can be filled sufficiently following the unevenness. Further, in the film adhesive according to the present invention, it is possible to suppress foaming of the adhesive by heating for a short time when the film adhesive is heated, and the elastic modulus is excessively increased by heating. By suppressing this, it is possible to suppress a gap from remaining between the film adhesive and the support member at the time of sealing the semiconductor element (during molding). With the film adhesive according to the present invention as described above, connection reliability can be improved in connection between the semiconductor element and the support member.

  In particular, in the film adhesive according to the present invention, even when a thin semiconductor element (for example, a thickness of 20 to 100 μm) is used, a gap remains between the film adhesive and the support member. Connection reliability can be improved.

  In the film-like adhesive according to the present invention, the gap can be eliminated at the time of sealing even when the gap is formed at the time of pressure bonding while sufficiently filling the adhesive following the unevenness at the time of pressure bonding. In addition, it is not necessary to complicate the manufacturing process of the semiconductor device in order to prevent the generation of voids during crimping, and the semiconductor device can be obtained stably and easily.

  It is preferable that content of the hardening accelerator in the film adhesive which concerns on this invention is 0.07 mass part or less on the basis of 100 mass parts of thermosetting components. In this case, before the semiconductor element is sealed, it is possible to further suppress the film-like adhesive from rapidly curing and increasing the elastic modulus. Thereby, it is possible to further suppress the gap from remaining between the film adhesive and the support member at the time of sealing the semiconductor element, and the connection reliability can be further improved.

  The film adhesive according to the present invention is thermosetting, has a shear viscosity of 200 to 11000 Pa · s at 80 ° C., and has a tensile elastic modulus at 150 ° C. of 0.01 MPa or more when heated at 140 ° C. for 30 minutes. It is preferable that the tensile elastic modulus at 175 ° C. when heated at 150 ° C. for 1 hour after heating at 140 ° C. for 30 minutes is 20 MPa or less. In this case, it is possible to further improve the connection reliability by satisfactorily embedding the gap under the wire at the time of crimping and sufficiently eliminating the gap at the adhesion interface at the time of sealing.

  The adhesive strength after curing with respect to the SiN film in the film adhesive according to the present invention is preferably 1.0 MPa or more. In this case, even when a film adhesive is adhered to the SiN film of the support member having the SiN film, connection reliability can be improved.

  The adhesive sheet which concerns on this invention is equipped with a base film and the said film adhesive arrange | positioned on the said base film. Also in the adhesive sheet according to the present invention, the connection reliability can be improved in the connection between the semiconductor element and the support member.

  The manufacturing method of the semiconductor device according to the present invention is a pressure bonding step in which a semiconductor element and a support member are pressure-bonded under the conditions of 80 to 140 ° C., 0.01 to 0.50 MPa, and 1 to 5 seconds through the film adhesive. And a first heating step of heating the film adhesive at 120 to 150 ° C. for 15 to 60 minutes after the crimping step, and a semiconductor element by heating at 150 ° C. or less for 1 hour or less after the first heating step. After the second heating step, the semiconductor element is sealed with resin under the conditions of 170 to 185 ° C., 4.5 to 8.0 MPa, and 60 to 180 seconds after the second heating step. And a sealing step to stop.

  In such a method of manufacturing a semiconductor device according to the present invention, a film is formed by pressure-bonding a semiconductor element and a support member at 80 to 140 ° C., 0.01 to 0.50 MPa, and 1 to 5 seconds in a pressure bonding step. Formation of a gap between the adhesive and the support member can be suppressed. Moreover, even if it is a case where it is a case where it heats at 150 degrees C or less in the following 2nd heating process by passing through the 1st heating process which heats a film adhesive for 15 to 60 minutes at 120-150 degreeC, it is a film form Foaming of the adhesive can be sufficiently suppressed. Furthermore, by passing through a second heating step of heating at 150 ° C. or lower for 1 hour or shorter, resin sealing under conditions of 170 to 185 ° C., 4.5 to 8.0 MPa, 60 to 180 seconds in the sealing step Even when voids are formed in the crimping step, the voids can be sufficiently eliminated. In the method of manufacturing a semiconductor device according to the present invention as described above, connection reliability can be improved in the connection between the semiconductor element and the support member.

  In the method for manufacturing a semiconductor device according to the present invention, the support member has a wire, and the semiconductor element and the support member may be pressure-bonded so that the wire is covered with the film adhesive in the pressure-bonding step.

  According to the present invention, even when the unevenness is formed on the adhesive surface between the film adhesive and the support member when the semiconductor element and the support member are pressure-bonded, the adhesive sufficiently follows the unevenness. It is possible to suppress foaming of the adhesive during heating of the film adhesive, and there is a gap between the film adhesive and the support member during sealing of the semiconductor element. It is possible to suppress remaining. Thereby, in this invention, connection reliability can be improved in the connection of a semiconductor element and a supporting member. In the present invention, the film adhesive can be excellent in heat resistance, moisture resistance and reflow resistance.

  The film adhesive according to the present invention is suitably used for bonding a semiconductor element to a substrate having unevenness caused by a wiring circuit, a metal substrate such as a lead frame, in addition to a wire embedding application. For example, in a wire embedding application, a wire can be satisfactorily embedded with a film adhesive during pressure bonding.

It is sectional drawing which shows typically one Embodiment of the film adhesive which concerns on this invention. It is sectional drawing which shows typically one Embodiment of the adhesive sheet which concerns on this invention. It is sectional drawing which shows typically other one Embodiment of the adhesive sheet which concerns on this invention. It is sectional drawing which shows typically other one Embodiment of the adhesive sheet which concerns on this invention. It is sectional drawing which shows typically one Embodiment of the semiconductor device which concerns on this invention. It is sectional drawing which shows typically other one Embodiment of the semiconductor device which concerns on this invention. It is sectional drawing which shows typically the manufacturing method of the semiconductor device in an Example. It is drawing which shows the SEM photograph regarding evaluation of wire embedding property.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In this specification, “(meth) acryl” means “acryl” and “methacryl” corresponding to it.

<Film adhesive>
FIG. 1 is a cross-sectional view schematically showing a film adhesive according to the present embodiment. The film adhesive 1 is thermosetting, and is produced by forming a film-like adhesive composition that can be in a completely cured product (C stage) state after the curing process through a semi-cured (B stage) state. be able to.

  The film-like adhesive 1 contains (a) a thermosetting component, (b) a high molecular weight component, and (c) an inorganic filler, and is composed of an adhesive composition containing these components. ing. Hereinafter, each component will be described.

(A) Thermosetting component (a) The thermosetting component is, as a thermosetting resin, (a1) a first epoxy resin having a softening point of 85 ° C or higher and an epoxy equivalent of 500 or higher, and softening At least one of a first phenol resin having a point of 85 ° C. or higher and a hydroxyl group equivalent (phenol equivalent) of 500 or higher; and (a2) a second softening point of 85 ° C. or higher and an epoxy equivalent of 150 or lower. And at least one of a second phenolic resin having a softening point of 85 ° C. or higher and a hydroxyl group equivalent (phenol equivalent) of 150 or lower, and (a3) a third softening point of 75 ° C. or lower. And at least one of an epoxy resin and a third phenol resin. Thus, by containing (a1) component-(a3) component, while suppressing that a film adhesive foams in a semiconductor device manufacturing process, a film adhesive and support at the time of sealing of a semiconductor element are supported. It is possible to suppress a gap from remaining between the members.

  The softening point of the component (a1) and the component (a2) is 85 ° C. or higher, and preferably 90 ° C. or higher. Since the connection process of semiconductor elements, such as a wire bonding process, is often performed at a high temperature of 150 ° C. or higher, the film adhesive is preheated in order to suppress foaming at 150 ° C. or higher to promote curing. It is necessary to keep. When the softening point of the component (a1) and the component (a2) is 85 ° C. or higher, the film adhesive can be heated at 120 to 150 ° C. without foaming. The softening point can be measured using a ring and ball softening point test method based on JIS K7234.

  The epoxy equivalent and hydroxyl equivalent of the component (a1) are 500 or more, preferably 600 or more, and more preferably 700 or more. By setting the epoxy equivalent and the hydroxyl equivalent to 500 or more, it is possible to suppress an excessive elastic modulus in the heating process and to sufficiently eliminate voids at the adhesive interface during sealing.

  The epoxy equivalent and hydroxyl equivalent of the component (a2) are 150 or less, preferably 135 or less. By setting the epoxy equivalent and the hydroxyl equivalent to 150 or less, a smooth increase in elastic modulus can be realized in the initial heating step, and foaming of the film adhesive in the subsequent step can be suppressed.

  The combination of the (a1) component and the (a2) component realizes a smooth increase in elastic modulus in the initial heating step, while suppressing foaming of the film adhesive, while increasing the elastic modulus in the subsequent heating step. It is possible to suppress the gap at the adhesive interface during sealing.

  (A1) Content of a component is 10-40 mass parts on the basis of 100 mass parts of (a) thermosetting components, and 15-35 mass parts is preferable. When the content of the component (a1) is 10 to 40 parts by mass, the tensile modulus at 175 ° C. when heated at 150 ° C. for 1 hour after heating at 140 ° C. for 30 minutes can easily be 20 MPa or less. In addition, it is possible to eliminate the gap at the adhesive interface well during sealing.

  (A2) Content of a component is 5-20 mass parts on the basis of 100 mass parts of (a) thermosetting components, and 5-15 mass parts is preferable. When the content of the component (a2) is 5 to 20 parts by mass, the tensile elastic modulus at 150 ° C. when heated at 140 ° C. for 30 minutes can be easily increased to 0.01 MPa or more, and the semiconductor device manufacturing process The foaming of the film adhesive can be suppressed.

  (A3) The softening point of a component is 75 degrees C or less. By setting the softening point to 75 ° C. or lower, it is possible to satisfactorily bury a step such as a wire in the crimping process. The component (a3) is preferably liquid at normal temperature (25 ° C.) (that is, the softening point is preferably 25 ° C. or less). Moreover, it is preferable that (a3) component is at least one of the 3rd epoxy resin whose softening point is less than 75 degreeC, and the 3rd phenol resin whose softening point is 75 degrees C or less.

  (A3) Component content is 25-55 mass parts on the basis of 100 mass parts of (a) thermosetting component, 30-50 mass parts is preferable and 35-50 mass parts is more preferable. When the content of the component (a3) is 25 to 55 parts by mass, a step such as a wire can be satisfactorily embedded in the crimping process.

  Examples of the component (a1) include SR35K manufactured by Printec Co., Ltd. Examples of the component (a2) include KA and TD series manufactured by DIC Corporation. Examples of the component (a3) include R710 and VG3101L manufactured by Printec Co., Ltd., HE200C-10 manufactured by Air Water Co., and GAN manufactured by Nippon Kayaku Co., Ltd.

  The epoxy resin that does not correspond to the components (a1) to (a3) is not particularly limited as long as it is cured and has an adhesive action, such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol E type epoxy resin. Novolak type epoxy resins such as bifunctional epoxy resins, phenol novolac type epoxy resins or cresol novolak type epoxy resins can be used. Moreover, what is generally known, such as a polyfunctional epoxy resin, a glycidyl amine type epoxy resin, a heterocyclic containing epoxy resin, or an alicyclic epoxy resin, can also be used as an epoxy resin.

  The phenol resin not corresponding to the components (a1) to (a3) is preferably a phenol resin having a large hydroxyl equivalent. Examples of such phenolic resins include the Millex XLC-series and XL series (for example, Millex XLC-LL) manufactured by Mitsui Chemicals, the HE series (for example, HE910-10) manufactured by Air Water, Examples include naphthol resin SN series manufactured by Kasei Co., Ltd.

  (A) When a thermosetting component contains an epoxy resin and a phenol resin, the content (blending amount) of the epoxy resin and the phenol resin is 0.70 / 0.30-0 in terms of an equivalent ratio of epoxy equivalent and hydroxyl equivalent, respectively. .30 / 0.70 is preferable, 0.65 / 0.35 to 0.35 / 0.65 is more preferable, 0.60 / 0.40 to 0.40 / 0.60 is still more preferable, and 0.60 /0.40 to 0.50 / 0.50 is particularly preferable. When the content ratio exceeds the range of 0.70 / 0.30 to 0.30 / 0.70, the curability of the produced film adhesive tends to be inferior and the viscosity of the uncured film adhesive Tends to be high and inferior in fluidity. The content of the epoxy resin is the sum of the content of the epoxy resin corresponding to the components (a1) to (a3) and the content of the epoxy resin not corresponding to the components (a1) to (a3). The content of the phenol resin is the sum of the content of the phenol resin corresponding to the components (a1) to (a3) and the content of the phenol resin not corresponding to the components (a1) to (a3).

(B) High molecular weight component (b) The high molecular weight component has a crosslinkable functional group such as an epoxy group (glycidyl group), an alcoholic group, a phenolic hydroxyl group, or a carboxyl group. For example, polyimide resin, (meth) acrylic Resins, urethane resins, polyphenylene ether resins, polyetherimide resins, phenoxy resins, and modified polyphenylene ether resins. The (b) high molecular weight component excludes those corresponding to the (a) thermosetting component.

  (B) As the high molecular weight component, a (meth) acrylic resin is preferable, and Tg (glass transition temperature) obtained by polymerizing a functional monomer having an epoxy group such as glycidyl acrylate or glycidyl methacrylate as a crosslinkable functional group. (Meth) acrylic resins such as an epoxy group-containing (meth) acrylic copolymer having a weight average molecular weight of 100,000 to 800,000 and a weight average molecular weight of -50 ° C to 50 ° C are more preferred.

  Examples of such a resin include an epoxy group-containing (meth) acrylic acid ester copolymer, an epoxy group-containing acrylic rubber, and the like, and an epoxy group-containing acrylic rubber is preferable. The epoxy group-containing acrylic rubber is a rubber having an epoxy group mainly composed of an acrylate ester and mainly composed of a copolymer such as butyl acrylate and acrylonitrile, a copolymer such as ethyl acrylate and acrylonitrile, or the like. .

  (B) Tg (glass transition temperature) of the high molecular weight component is -50 ° C to 50 ° C, preferably -20 ° C to 40 ° C, and more preferably -10 ° C to 30 ° C. (B) When the Tg of the high molecular weight component exceeds 50 ° C., the flexibility of the film adhesive is lowered, and when the Tg is less than −50 ° C., the flexibility of the film adhesive is too high. Sometimes the film adhesive is difficult to cut, and dicing is reduced due to the generation of burrs. The glass transition temperature can be measured using a DSC (thermal differential scanning calorimeter) (for example, “Thermo Plus 2” manufactured by Rigaku Corporation).

  (B) The weight average molecular weight of the high molecular weight component is 100,000 to 1,000,000, preferably 100,000 to 900,000, more preferably 100,000 to 800,000, and still more preferably 150,000 to 800,000. (B) When the weight average molecular weight of the high molecular weight component is less than 100,000, the film-forming property is lowered and the adhesive strength and heat resistance of the film adhesive are lowered. When the weight average molecular weight is more than 1,000,000, The cutting property and breakability of the uncured film adhesive are lowered, and the quality of dicing is lowered. The weight average molecular weight is a polystyrene conversion value using a standard polystyrene calibration curve by gel permeation chromatography (GPC).

  (B) It is easy to cut the film adhesive at the time of wafer dicing, it is difficult to generate resin waste, the adhesive strength and heat resistance are further increased, and the fluidity of the uncured film adhesive is further increased (b ) The high molecular weight component is preferably a high molecular weight component having a Tg of -20 ° C to 40 ° C and a weight average molecular weight of 100,000 to 700,000, a Tg of -10 ° C to 30 ° C and a weight average molecular weight of 15 High molecular weight components that are 10,000 to 550,000 are more preferred.

  (B) Content of a high molecular weight component is 20-100 mass parts with respect to 100 mass parts of (a) thermosetting components, 30-80 mass parts is preferable and 30-70 mass parts is more preferable. When the content is less than 20 parts by mass, the flexibility of the film is lowered and the elasticity is increased after heating, and it becomes difficult to embed voids at the time of sealing. On the other hand, when content exceeds 100 mass parts, the fluidity | liquidity of an uncured film will fall and the adhesive strength after hardening will fall.

  (B) As a high molecular weight component, you may use what mixed the high molecular weight component superposed | polymerized from the different monomer, and what mixed the high molecular weight component which has a different molecular weight. In particular, when only a high molecular weight component having a low weight average molecular weight (for example, about 250,000) is used, although the fluidity of the uncured film is high, the adhesive strength after curing tends to decrease. For this reason, mixing a high molecular weight component having a high weight average molecular weight (for example, about 800,000) can be an effective means. However, if the content of the high molecular weight component having a high weight average molecular weight is large, the fluidity of the uncured film tends to decrease. Therefore, the content of the high molecular weight component having a high weight average molecular weight is (b) high molecular weight. About 10 to 40% is preferable based on the total mass of the components.

  The amount of the crosslinkable functional group is 3 to 15% in terms of the monomer ratio in order to smoothly increase the tensile elastic modulus when heated at 120 ° C. for 1 hour and develop high adhesive strength after curing, at 150 ° C. From the viewpoint of easily maintaining a low tensile elastic modulus when heated for 1 hour, 3 to 10% is preferable. The abundance of the crosslinkable functional group can be adjusted by adjusting the monomer ratio of the functional monomer such as glycidyl acrylate or glycidyl methacrylate to the above range.

  (B) The high molecular weight component can also be obtained as a commercial product. (B) As a high molecular weight component, Nagase ChemteX Co., Ltd. brand name "acrylic rubber HTR-860P" etc. are mentioned, for example. This compound has a glycidyl moiety as a crosslinkable functional group and is based on an acrylic rubber made of an acrylic acid derivative, and has a weight average molecular weight of 800,000 and a Tg (glass transition temperature) of −7 ° C. .

(C) Inorganic filler (c) As an inorganic filler, the improvement of the dicing property of the film adhesive in a B-stage state, the improvement of the handleability of the film adhesive, the improvement of thermal conductivity, the adjustment of the melt viscosity, thixotropic From the viewpoint of imparting properties and improving adhesive strength, it is preferable to add a silica filler.

  (C) The content of the inorganic filler is (a) 100 parts by mass of a thermosetting component from the viewpoint of controlling the fluidity of the uncured film adhesive and the tensile modulus and adhesive strength of the cured film adhesive. It is 10-80 mass parts with respect to 40, 80 mass parts. When the content is less than 10 parts by mass, the dicing property of the uncured film adhesive is lowered, and the adhesive strength after curing is lowered. On the other hand, when content exceeds 80 mass parts, the fluidity | liquidity of an uncured film adhesive will fall and the tensile elasticity modulus after hardening will become high.

  Inorganic fillers having different average particle diameters can be mixed and used, but from the viewpoint of improving dicing properties, an inorganic filler having an average particle diameter of 0.1 to 5 μm is selected from (c) the inorganic filler. It is preferable to use it as the main filler component occupying a proportion of 80% by mass or more based on the total mass.

  When an inorganic filler having an average particle size of less than 0.1 μm is used as a main filler component, the fluidity of the uncured film adhesive may decrease due to an increase in specific surface area and an increase in the number of contained particles. When an inorganic filler having a diameter exceeding 5 μm is used as the main filler component, it may cause a decrease in adhesive strength due to a decrease in the number of contained particles, or a decrease in film film formability.

  In addition, the inorganic filler having different average particle diameters added to the main filler component is not particularly limited as long as it does not exceed the film thickness of the film adhesive to be produced. For the purpose of elasticity etc., a filler having an average particle size of 5 μm or more is preferable, and suppression of foaming of the film adhesive in the manufacturing process of a semiconductor element due to an extreme decrease in viscosity, For the purpose of improvement, a filler having an average particle size of 0.1 μm or less is preferable.

(D) Curing accelerator It is preferable that the film adhesive 1 further contains (d) a curing accelerator. (D) As the curing accelerator, an imidazole compound is preferable.

  A curing accelerator that is too reactive causes rapid curing of the film adhesive during the manufacturing process of the semiconductor element, and tends to have a high tensile elastic modulus when heated at 150 ° C. for 1 hour. On the other hand, a curing accelerator having a reactivity that is too low makes it difficult for the film adhesive to be completely cured by the thermal history in the manufacturing process of the semiconductor element, and it is mounted in the product without being cured. Problems may occur.

  The content of the curing accelerator is preferably 0.07 parts by mass or less (0 to 0.07 parts by mass) with respect to 100 parts by mass of the (a) thermosetting component, and should be mounted in the product uncured. 0.01 to 0.07 parts by mass is more preferable from the viewpoint of facilitating suppression. When the content of the curing accelerator exceeds 0.07 parts by mass, the film-like adhesive is suddenly cured during the manufacturing process of the semiconductor element, and the tensile elastic modulus when heated at 150 ° C. for 1 hour tends to increase. It is in.

(E) Other components It is preferable that the film adhesive 1 contains a coupling agent from a viewpoint of improving adhesiveness other than said (a)-(d). Examples of the coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and the like.

  The film adhesive 1 preferably has a film thickness of 5 to 200 μm in order to sufficiently fill irregularities such as wires for connecting semiconductor elements and wiring circuits on the substrate. If the film thickness is less than 5 μm, the adhesive strength tends to be poor. If the film thickness is more than 200 μm, the film is not economical and tends to make it difficult to meet the demand for downsizing of the semiconductor device. In addition, 10-100 micrometers is more preferable and the film thickness of the film adhesive 1 is still more preferable 20-75 micrometers from the point which has high adhesiveness and can make a semiconductor device thin.

  The film-like adhesive 1 has a shear viscosity of 200 to 11000 Pa · s at 80 ° C. before curing, a tensile elastic modulus at 150 ° C. of 30 MPa when heated at 140 ° C. for 30 minutes, and 140 ° C. It is preferable that the tensile elastic modulus at 175 ° C. when heated for additional 1 hour at 150 ° C. after heating for 30 minutes is 20 MPa or less.

  When the shear viscosity at 80 ° C. is 200 to 11000 Pa · s, the gap or substrate under the wire is crimped under conditions of 80 ° C. or higher (for example, 80 to 140 ° C.), 0.01 to 0.50 MPa, and 1 to 5 seconds. Unevenness resulting from the step can be easily embedded. By using an epoxy resin or a phenol resin having a softening point of 80 ° C. or lower, it becomes easy to adjust the shear viscosity to 200 to 11000 Pa · s. The shear viscosity is measured using ARES (manufactured by Rheometric Scientific) and increasing the temperature at a rate of temperature increase of 5 ° C./min while applying 5% strain to the film adhesive 1. Means the measured value.

  When the tensile elastic modulus at 150 ° C. when heated at 140 ° C. for 30 minutes is 0.01 MPa or more, foaming when the film adhesive 1 is heated at 150 ° C. can be easily suppressed. (B) adjusting the crosslinkable functional group of the high molecular weight component to 3 to 15% by monomer ratio, (d) adjusting the content of the curing accelerator to 0.07 parts by mass or less, or the second By adjusting the content of the epoxy resin to 5 to 20 parts by mass based on 100 parts by mass of the (a) thermosetting component, it becomes easy to adjust the tensile elastic modulus to 0.01 MPa or more.

  Moreover, when it heats at 140 degreeC for 30 minutes and is further heated at 150 degreeC for 1 hour, when the tensile elasticity modulus in 175 degreeC is 20 Mpa or less, it is 170-185 degreeC (for example, 175 degreeC), 4.5-8. When the semiconductor element is resin-sealed under sealing conditions such as 0 MPa and 60 to 180 seconds (for example, 90 seconds), remaining voids can be easily lost. By setting the content of the first epoxy resin to 10 to 40 parts by mass, it becomes easy to adjust the tensile elastic modulus to 20 MPa or less. In addition, a tensile elasticity modulus means the measured value at the time of measuring, using a dynamic viscoelasticity measuring apparatus (made by UBM Co., Ltd.) at a temperature rising rate of 3 ° C./min.

  It is preferable that the adhesive strength (adhesive force) after hardening with respect to the SiN film in the film adhesive 1 is 1.0 MPa or more. The SiN film is, for example, a thin film having a thickness of 0.05 to 1.00 μm. The adhesive strength of the film adhesive 1 can be adjusted by the contents of the above (a) to (e), etc., and it is sufficient that the film adhesive 1 contains an additive such as (e) a coupling agent. High adhesive strength can be easily obtained. The adhesive strength is an adhesive strength after curing the film adhesive 1 adhered to the SiN film in an uncured or semi-cured state, and can be measured as a die shear strength.

<Method for producing film adhesive>
The film adhesive 1 can be produced from a varnish of an adhesive composition containing at least the above (a) to (c). Specifically, first, (a) a thermosetting component, (b) a high molecular weight component, (c) an essential component of an inorganic filler, and (d) a curing accelerator, a coupling agent, etc. as necessary The varnish is prepared by mixing and kneading these additives with an organic solvent.

  Next, a varnish layer is formed by apply | coating the obtained varnish on a base film. Then, after removing a solvent from a varnish layer by heat drying, the film adhesive 1 is obtained by removing a base film.

  The above mixing and kneading can be performed by using a normal stirrer, a roughing machine, a three-roller, a ball mill or the like and appropriately combining these. The above heat drying is not particularly limited as long as the solvent used is sufficiently volatilized, but can be usually performed by heating at 60 to 200 ° C. for 0.1 to 90 minutes.

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

  The organic solvent is not particularly limited as long as it can uniformly dissolve, knead or disperse the above components, and a conventionally known organic solvent can be used. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dimethylformamide, dimethylacetamide, N methylpyrrolidone, toluene, xylene, and the like. As the organic solvent, it is preferable to use methyl ethyl ketone, cyclohexanone, or the like from the viewpoints of high drying speed and low price.

<Adhesive sheet>
The film adhesive 1 may be used alone, but may be used as an adhesive sheet in which the film adhesive 1 is disposed on a base film. The film adhesive 1 may be arrange | positioned in contact with a base film, and may be arrange | positioned on a base film through an adhesive layer etc.

  FIG. 2 is a cross-sectional view schematically showing the adhesive sheet according to the present embodiment. An adhesive sheet 100 shown in FIG. 2 includes a base film 2 and a film adhesive 1 disposed on one main surface 2 a of the base film 2.

  The adhesive sheet 100 can be obtained by laminating the film adhesive 1 obtained in advance on the base film 2. Moreover, as one of the methods for manufacturing the thicker adhesive sheet 100, the film-like adhesive 1 obtained in advance and the film-like adhesive 1 of the adhesive sheet 100 can be bonded together.

  FIG. 3 is a cross-sectional view schematically showing an adhesive sheet according to another embodiment. The adhesive sheet 110 shown in FIG. 3 includes a base film 2, a film adhesive 1 disposed on one main surface 2 a of the base film 2, and a cover film 3 disposed on the film adhesive 1. And. That is, the cover film 3 is disposed on the main surface 1 a opposite to the base film 2 in the film adhesive 1 disposed on the base film 2.

  Examples of the base film 2 in the adhesive sheets 100 and 110 include a PET film and an OPP film. Examples of the cover film 3 include a PET film, a PE film, and an OPP film.

  The adhesive sheet may be a dicing / die bonding integrated adhesive sheet in which the film adhesive 1 is laminated on a conventionally known dicing tape. In this case, the efficiency of the operation can be improved in that the laminating process on the wafer is performed only once.

  Examples of such a dicing / die bonding integrated adhesive sheet include those having the configuration shown in FIG. The adhesive sheet 120 shown in FIG. 4 supports a dicing tape in which the pressure-sensitive adhesive layer 6 is disposed on one main surface 7a of the base film 7 that can ensure elongation (commonly referred to as expanded) when a tensile tension is applied. It has a structure in which the film adhesive 1 is disposed on one main surface 6a of the pressure-sensitive adhesive layer 6 of the dicing tape.

  Examples of the substrate film 7 include plastic films such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film. The pressure-sensitive adhesive layer 6 is, for example, applied to a substrate film 7 with a resin composition containing a liquid component and a high molecular weight component and having an appropriate tack strength, and dried, or applied to a substrate film such as a PET film. It can be formed by bonding the dried material to the base film 7. The tack strength is set to a desired value, for example, by adjusting the ratio of the liquid component and the Tg of the high molecular weight component. The dicing tape may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, etc., if necessary.

  When the dicing / die bonding integrated adhesive sheet is used in the manufacture of a semiconductor device, it must have an adhesive force that prevents the semiconductor elements from scattering during dicing, and can be easily peeled off from the dicing tape during subsequent pick-up. Such characteristics can be obtained by adjusting the tack strength of the pressure-sensitive adhesive layer 6 and changing the tack strength by photoreaction as described above. However, if the tackiness of the film adhesive 1 is too high, picking up is difficult. May be. Therefore, it is preferable to appropriately adjust the tack strength of the film adhesive 1. As the method, for example, when the flow of the film adhesive 1 at room temperature (25 ° C.) is increased, the adhesive strength and tack strength tend to increase, and when the flow is decreased, the adhesive strength and tack strength are also decreased. You can take advantage of this tendency.

  For example, when increasing the flow, a method of increasing the content of a compound that functions as a plasticizer can be used. In the case of reducing the flow, for example, a method of reducing the content of a compound that functions as a plasticizer can be mentioned. Examples of the plasticizer include monofunctional acrylic monomers, monofunctional epoxy resins, liquid epoxy resins, and acrylic resins.

  As a method of laminating the film-like adhesive 1 on the dicing tape, the above-described film-like adhesive is prepared in addition to the above-described method of applying the varnish to the entire surface of the dicing tape and drying, or partially applying it by printing. The method of laminating | stacking 1 on a dicing tape by a press and hot roll lamination is mentioned. In the present embodiment, a hot roll laminating method is preferable because it can be continuously manufactured and is efficient.

  The film thickness of the dicing tape is not particularly limited, and can be appropriately determined based on the knowledge of those skilled in the art depending on the film thickness of the film adhesive 1 and the application of the dicing tape-integrated adhesive sheet. When the thickness of the dicing tape is less than 60 μm, the handleability tends to be insufficient, and the dicing tape tends to be broken by the expand in the step of peeling the chips diced by dicing from the dicing tape. On the other hand, the thickness of the dicing tape is preferably 180 μm or less from the viewpoint of economy and good handleability. From the above viewpoint, the film thickness of the dicing tape is preferably 60 to 180 μm.

<Semiconductor device>
As a use of the film adhesive 1, a semiconductor device (semiconductor package) including the film adhesive 1 will be specifically described with reference to the drawings. In recent years, semiconductor devices having various structures have been proposed, and the use of the film adhesive 1 is not limited to the semiconductor devices having the structure described below.

  FIG. 5 is a cross-sectional view schematically showing the semiconductor device according to the present embodiment. The semiconductor device 200 shown in FIG. 5 includes a semiconductor element mounting support substrate 9, cured products (adhesive members) 11a and 11b of the film adhesive 1, a first-stage semiconductor element 13a, and a second-stage semiconductor element 13b. And a sealing material 15. The semiconductor element mounting support substrate 9, the cured product 11a, and the semiconductor element 13a constitute a support member 17 of the semiconductor element 13b.

  A plurality of external connection terminals 19 are arranged on one main surface 9 a of the semiconductor element mounting support substrate 9, and a plurality of terminals 21 are arranged on the other main surface 9 b of the semiconductor element mounting support substrate 9. Yes. The semiconductor element mounting support substrate 9 has wires 23 for electrically connecting the connection terminals (not shown) of the semiconductor elements 13 a and 13 b and the external connection terminals 19. The semiconductor element 13a is bonded to the semiconductor element mounting support substrate 9 via a cured product 11a disposed on the main surface 9a. The semiconductor element 13b is bonded to the semiconductor element 13a via a cured product 11b disposed on the semiconductor element 13a. The semiconductor element 13 a, the semiconductor element 13 b, and the wire 23 are sealed with a sealing material 15. Thus, the film adhesive 1 can be suitably used for a semiconductor device having a structure in which a plurality of semiconductor elements are stacked.

  FIG. 6 is a cross-sectional view schematically showing a semiconductor device according to another embodiment. A semiconductor device 210 shown in FIG. 6 includes a semiconductor element mounting support substrate 9, a cured product 11 of the film adhesive 1, a semiconductor element 13, and a sealing material 15. The semiconductor element mounting support substrate 9 is a support member for the semiconductor element 13, and includes a connection terminal (not shown) of the semiconductor element 13 and an external connection terminal (on the main surface 9 a of the semiconductor element mounting support substrate 9). A wire 23 for electrically connecting to a wire (not shown) is provided. The semiconductor element 13 is bonded to the semiconductor element mounting support substrate 9 via a cured product 11 disposed on the main surface 9 a of the semiconductor element mounting support substrate 9. The semiconductor element 13 and the wire 23 are sealed with a sealing material 15.

<Method for Manufacturing Semiconductor Device>
The semiconductor device according to this embodiment can be obtained by using the film adhesive 1. For example, the semiconductor devices 200 and 210 shown in FIGS. 5 and 6 are chips to which the film adhesive 1 is bonded. (Hereinafter referred to as “chip with adhesive”).

  After the adhesive chip and the dicing tape are bonded individually or collectively as a dicing / die bonding integrated adhesive sheet to the wafer or the chip already fragmented at 0 to 90 ° C., It can be obtained by cutting or stretching with a rotary blade or laser. When the film adhesive 1 is used alone instead of the adhesive sheet, the dicing tape may be attached to the film adhesive surface after the film adhesive 1 is attached to the wafer.

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

  The temperature at which the film adhesive 1 is attached to the wafer, that is, the laminating temperature, is usually 0 to 90 ° C, preferably 15 to 80 ° C, and more preferably 40 to 80 ° C. When the laminating temperature exceeds 90 ° C., a change in thickness due to excessive melting of the film adhesive 1 may become remarkable. When the dicing tape or the dicing / die bonding integrated adhesive sheet is attached, it is preferably performed at the above temperature.

  Hereinafter, the method for manufacturing the semiconductor device according to the present embodiment will be described using the method for manufacturing the semiconductor device 200 shown in FIG. 5 as an example. The manufacturing method of the semiconductor device according to the present embodiment includes a crimping step, a first heating step, and a sealing step in this order, and a wire bonding step or the like between the first heating step and the sealing step. A second heating step is optionally provided.

  In the crimping step, the semiconductor element (first semiconductor element) 13b and the support member 17 are crimped through the film adhesive 1 under the conditions of 80 to 140 ° C., 0.01 to 0.50 MPa, and 1 to 5 seconds. It is preferable to do. In the present embodiment, by using the film adhesive 1, it is possible to satisfactorily embed irregularities derived from the gap under the wire or the step of the substrate, and the semiconductor element 13b and the support member 17 are pressure-bonded under the above conditions. Thus, it is possible to embed unevenness more satisfactorily.

  The support member 17 can be obtained by connecting the semiconductor element mounting support substrate 9 and the semiconductor element (second semiconductor element) 13 a via the cured product 11 a of the film adhesive 1. The support member 17 includes a wire 23 that electrically connects the semiconductor element 13 b and the semiconductor element mounting support substrate 9 of the support member 17. In the crimping step, for example, the semiconductor element 13b and the support member 17 are crimped so that at least a part of the wire 23 is covered with the film adhesive 1.

  Instead of the support member 17, a substrate having irregularities on the adhesive surface with the film adhesive may be used. In this case, in the crimping step, the semiconductor element and the support member are crimped so that the adhesive is filled following the shape of the unevenness.

  The load in the crimping step is preferably 0.01 to 0.50 MPa, and more preferably 0.02 to 0.2 MPa. If the load is less than 0.01 MPa, an unfilled portion is excessively present, and a semiconductor element (for example, a chip) moves due to pressure at the time of sealing, which may deteriorate the quality of the semiconductor device. On the other hand, when the crimping load exceeds 0.50 MPa, the semiconductor element may be damaged.

  80-140 degreeC is preferable and the heating temperature in a crimping | compression-bonding process has more preferable 80-130 degreeC. When the heating temperature is less than 80 ° C., the embedding property of the wire and the embedding property of the unevenness tend to be lowered. On the other hand, when heating temperature exceeds 140 degreeC, there exists a tendency for the film adhesive 1 to foam or for a support member (for example, board | substrate) to deform | transform and to warp.

  When a chip with an adhesive is pressure-bonded to a substrate having an uneven surface, it is preferable to heat the support member and / or the chip with an adhesive. Examples of the heating method include a method of bringing a heating target into contact with a heated hot plate, irradiating the heating target with infrared rays or microwaves, and blowing hot air on the heating target.

  The first heating step is a heat treatment step for preventing foaming in the subsequent step of the film adhesive. In the first heating step, the film adhesive 1 is heated (heat treated) at 120 to 150 ° C. for 15 to 60 minutes. In the present embodiment, the film adhesive 1 is subjected to a heat treatment at 120 to 150 ° C./15 to 60 minutes, so that the film is used in the second heating step between the first heating step and the sealing step. Even if the adhesive 1 is heated, foaming of the adhesive can be suppressed.

  In the second heating step, the heat history is adjusted to 150 ° C. or less and 1 hour or less. In the second heating step, for example, the film adhesive 1 is heated (heat treated) under conditions of 150 ° C. or lower and 1 hour or shorter. The lower limit value of the heating temperature is, for example, 120 ° C. The lower limit of the heating time is preferably 2 minutes. In the second heating step, for example, the wire for electrically connecting the semiconductor element 13b bonded to the support member 17 via the film adhesive 1 and the external connection terminal of the support member 17 by a wire 23 such as a gold wire. It is a bonding process.

  In the present embodiment, the thermal history in the second heating step is 150 ° C. or less and 1 hour or less, so that the thermosetting of the film adhesive 1 is prevented from proceeding excessively. A low elasticity state can be maintained. Thereby, even if it is a case where a space | gap remains after pressure bonding, a space | gap can be further lose | disappeared in a sealing process.

  In the sealing step, the semiconductor elements 13a and 13b and the wires 23 are resin-sealed under sealing conditions of 170 to 185 ° C., 4.5 to 8.0 MPa, and 60 to 180 seconds. By adopting the sealing conditions, a semiconductor device with high connection reliability can be easily obtained. After the sealing step, for example, the sealing material and the film adhesive 1 may be heated and cured under conditions of 175 ° C. and 5 hours.

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

(Examples 1-2 and Comparative Examples 1-3)
Cyclohexanone is added to a composition containing (a) an epoxy resin and a phenol resin as thermosetting components, and (c) an inorganic filler, with the product names and composition ratios (unit: parts by mass) shown in Table 1, and mixed by stirring. To obtain a mixture. Next, (b) acrylic rubber as a high molecular weight component similarly shown in Table 1 is added to the above mixture and stirred, and a coupling agent similarly shown in Table 1 and (d) a curing accelerator are further added. Was stirred to obtain a varnish.

In addition, the name of each component in Table 1 means the following.
(Epoxy resin)
R710: (trade name, manufactured by Printec Co., Ltd., bisphenol E type epoxy resin, epoxy equivalent: 170, liquid at normal temperature).
VG3101L: (trade name, manufactured by Printec Co., Ltd., epoxy resin, epoxy equivalent: 210, softening point: 39 to 46 ° C).
GAN: (trade name, Nippon Kayaku Co., Ltd., epoxy resin, epoxy equivalent: 119, liquid at room temperature).
SR35K: (trade name, manufactured by Printec Co., Ltd., epoxy resin, epoxy equivalent: 930-940, softening point: 86-98 ° C.).
YDCN-700-10: (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent: 210, softening point: 75 to 85 ° C).

(Phenolic resin)
Millex XLC-LL: (trade name, manufactured by Mitsui Chemicals, phenol resin, hydroxyl group equivalent: 175, softening point: 77 ° C.).
HE910-10: (trade name, manufactured by Air Water Co., Ltd., phenol resin, hydroxyl group equivalent: 201, softening point: 78-88 ° C).
KA1163: (trade name, manufactured by DIC Corporation, phenol resin, hydroxyl group equivalent: 118, softening point: 105 to 115 ° C).
TD2093Y: (trade name, manufactured by DIC Corporation, phenol resin, hydroxyl group equivalent: 104, softening point: 98-102 ° C).
HE200C-10: (trade name, manufactured by Air Water Co., Ltd., phenol resin, hydroxyl group equivalent: 200, softening point: 65 to 75 ° C).

(High molecular weight component: Acrylic rubber)
HTR-prototype 24: (sample name, manufactured by Nagase ChemteX Corporation, weight average molecular weight: 230,000, glycidyl functional group monomer ratio: 8%, Tg: −7 ° C.).
HTR-860P: (trade name, manufactured by Nagase ChemteX Corporation, weight average molecular weight: 800,000, glycidyl functional group monomer ratio: 3%, Tg: −7 ° C.).

(Inorganic filler)
Aerosil R972: (trade name, manufactured by Nippon Aerosil Co., Ltd., silica, average particle size: 0.016 μm).
SC1030-HJA: (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion, average particle size: 0.25 μm).

(Curing accelerator)
Cureazole 2PZ-CN: (trade name, manufactured by Shikoku Kasei Kogyo Co., Ltd., 1-cyanoethyl-2-phenylimidazole).

(Coupling agent)
NUC A-189: (trade name, manufactured by GE Toshiba Corporation, γ-mercaptopropyltrimethoxysilane).
NUC A-1160: (trade name, manufactured by GE Toshiba Corporation, γ-ureidopropyltriethoxysilane).

  Next, the obtained varnish was filtered through a 100-mesh filter and vacuum degassed. The varnish after vacuum defoaming was applied onto a polyethylene terephthalate (PET) film having a thickness of 38 μm as a base film. The applied varnish was heat-dried in two steps of 90 ° C. for 5 minutes and then 140 ° C. for 5 minutes. This obtained the adhesive sheet provided with the film adhesive of thickness 60micrometer in a B-stage state on PET film as a base film.

<Evaluation of various physical properties>
About the film-like adhesive of the above-mentioned adhesive sheet, shear viscosity at 80 ° C., tensile elastic modulus at 150 ° C. when heated at 140 ° C./30 minutes, 175 ° C. when heated at 150 ° C./1 hour after heating at 140 ° C./30 minutes Measurements of tensile modulus and adhesive strength were performed, and wire embedding properties, foamability at 150 ° C., mold embedding properties, and reflow resistance were evaluated.

[Shear viscosity measurement]
The shear viscosity at 80 ° C. of the film adhesive was measured by the following method. First, the base film was peeled and removed from the three adhesive sheets, and three film adhesives were bonded at 70 ° C. to obtain a laminate having a thickness of 180 μm. Next, the laminate was punched into a 10 mm square in the thickness direction to obtain a square laminate having a 10 mm square and a thickness of 180 μm. A circular aluminum plate jig having a diameter of 8 mm was set on a dynamic viscoelastic device ARES (manufactured by Rheometric Scientific), and a laminate of the punched film adhesive was set on the jig. Then, it measured, raising temperature at a temperature increase rate of 5 degree-C / min, giving 5% distortion at 35 degreeC, and recorded the value of the shear viscosity in 80 degreeC as a measured value. The measurement results are shown in Table 2.

[Evaluation of wire embedding]
The wire embedding property of the film adhesive was evaluated by the following method. First, the film-like adhesive (thickness 60 μm) of the adhesive sheet was attached to a semiconductor wafer (size: 8 inches) having a thickness of 50 μm at 70 ° C. Next, they were diced into 7.5 mm square to obtain a semiconductor element (chip) 13b to which the film adhesive 1 was bonded (see FIG. 7).

  Subsequently, as shown in FIG. 7, the film-like adhesive 1 of the separated semiconductor element 13 b was pressure-bonded to the evaluation substrate 300 under the conditions of 120 ° C., 0.10 MPa, and 1 second to obtain a sample 400. In the evaluation substrate 300 shown in FIG. 7, the first-stage semiconductor element 13 a is bonded to the semiconductor element mounting support substrate 9 with the film adhesive 31. As the film adhesive 31, a film adhesive FH-900-20 manufactured by Hitachi Chemical Co., Ltd. was used. A wire 23 is connected to the semiconductor element 13a. The wires 23 are connected to two opposite sides, and 32 wires are arranged on each side at intervals of 225 μm. A sample 400 shown in FIG. 7 is obtained by pressure-bonding a chip (second-stage semiconductor element 13b + film adhesive 1) to an evaluation substrate 300.

  Regarding the obtained sample 400, the lower portions of all the wires 23 were observed by SEM. FIG. 8 is a drawing showing an SEM photograph relating to the evaluation of wire embeddability. FIG. 8A shows a photograph of a region where the film adhesive is not sufficiently embedded in the lower part of the wire. In FIG. 8B, the film adhesive is sufficiently embedded in the lower part of the wire. An area photo is shown.

  In the case of 90% or more of the total number of wires, when the lower part of the wire 23 is satisfactorily filled with the film adhesive 1, the wire embedding property is evaluated as “A” and the film adhesive When the wire satisfactorily filled with the agent 1 was less than 90%, it was evaluated as “B”. The evaluation results are shown in Table 2.

[Measurement of tensile modulus at 150 ° C after heating at 140 ° C for 30 minutes]
The tensile elastic modulus at 150 ° C. after heating the film adhesive at 140 ° C./30 minutes was measured by the following method. First, the base film was peeled and removed from the two adhesive sheets (thickness 60 μm), and then two film adhesives were bonded at 70 ° C. to obtain a laminate having a thickness of 120 μm. Next, the laminate was cut into a thickness of 4 mm and a length of 30 mm, and heated in an oven at 140 ° C. for 30 minutes. The obtained sample was set in a dynamic viscoelastic device (product name: Rheogel-E4000, manufactured by UMB Co., Ltd.), applied with a tensile load, measured at a frequency of 10 Hz and a temperature rising rate of 3 ° C./min, and 150 ° C. The measured value was recorded as the tensile modulus after heating at 140 ° C./30 minutes. The measurement results are shown in Table 2.

[Measurement of tensile modulus at 175 ° C. after heating at 140 ° C./30 minutes / 150 ° C./1 hour]
The tensile elastic modulus at 175 ° C. after heating the film adhesive at 140 ° C./30 minutes / 150 ° C./1 hour was measured by the following method. First, the base film was peeled and removed from the two adhesive sheets (thickness 60 μm), and then two film adhesives were bonded at 70 ° C. to obtain a laminate having a thickness of 120 μm. Next, the laminate was cut into a thickness of 4 mm and a length of 30 mm in the thickness direction, heated in an oven at 140 ° C. for 30 minutes, and then heated in an oven at 150 ° C. for 1 hour. The obtained sample was set in a dynamic viscoelastic device (product name: Rheogel-E4000, manufactured by UMB Co., Ltd.), applied with a tensile load, measured at a frequency of 10 Hz, and a heating rate of 3 ° C./min, and measured at 175 ° C. The measured value was recorded as the tensile elastic modulus after heating at 140 ° C./30 minutes / 150 ° C./1 hour. The measurement results are shown in Table 2.

[Evaluation of foamability at 150 ° C.]
The sample 400 obtained in the above [Evaluation of wire embedding] was inspected with an ultrasonic imaging apparatus SAT (manufactured by Hitachi Construction Machinery, product number FS200II, probe: 120 MHz) to confirm the void ratio (void ratio A). The “ratio of voids” is the ratio of the area occupied by voids to the area of the entire chip.

  Next, a separately prepared sample 400 was heated in an oven at 140 ° C. for 30 minutes. The obtained sample was left on a hot plate at 150 ° C. for 10 minutes, and then examined by SAT in the same manner as described above to confirm the void ratio (void ratio B).

Void ratios A and B were compared, and the foamability at 150 ° C. was confirmed based on the increase in the void ratio (void ratio B−void ratio A). The evaluation results are shown in Table 2. The evaluation criteria for foamability are as follows.
A: The increase in the void ratio is less than 10%.
B: Increase in void ratio is 10% or more.

[Evaluation of mold embedding]
Using the same sample 400 as in [Evaluation of wire embedding], the mold embedding property of the film adhesive was evaluated by the following method. First, the film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 50 μm at 70 ° C. Next, they were diced to 7.5 mm square to obtain a semiconductor element (chip) 13b to which the film adhesive 1 was adhered. Subsequently, as shown in FIG. 7, the film-like adhesive 1 of the separated semiconductor element 13 b was pressure-bonded to the evaluation substrate 300 under the conditions of 120 ° C., 0.10 MPa, and 1 second to obtain a sample 400.

  Subsequently, the obtained sample was heated at 140 ° C. for 30 minutes, and a thermal history (150 ° C., 1 hour) equivalent to wire bonding was given to the sample using a hot plate. Next, using a mold sealing material (manufactured by Hitachi Chemical Co., Ltd., trade name “CEL-9750ZHF10), resin sealing was performed under the conditions of 175 ° C./6.7 MPa / 90 seconds, and 175 ° C. for 5 hours. The sealing material was cured under conditions to obtain a package.

A part of the obtained package was analyzed by SAT, and the embeddability after sealing was confirmed based on the void ratio in the same manner as the evaluation of foamability. The evaluation results are shown in Table 2. The evaluation criteria for embeddability are as follows.
A: Void ratio is less than 15%.
B: The ratio of voids is 15% or more.

[Measurement of adhesive strength]
The die shear strength (adhesion strength) of the film adhesive was measured by the following method. First, the film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 400 μm at 70 ° C. Next, they were diced to 5.0 mm square to obtain chips. A sample was obtained by thermocompression bonding at 120 ° C., 0.1 MPa for 5 seconds on a 625 μm-thick semiconductor chip whose surface was treated with SiN on the film adhesive side of the separated chip. Thereafter, the adhesive of the obtained sample was cured by step cure in the order of 140 ° C. for 30 minutes, 150 ° C. for 1 hour, and 170 ° C. for 3 hours. Further, the sample after curing of the adhesive was allowed to stand for 168 hours under the conditions of 85 ° C. and 60 RH%. Thereafter, the sample was allowed to stand for 30 minutes under conditions of 25 ° C. and 50% RH, and the die shear strength was measured at 250 ° C., and this was taken as the adhesive strength. The measurement results are shown in Table 2.

[Evaluation of reflow resistance]
Using the same sample 400 as in [Evaluation of wire embedding], the reflow resistance of the film adhesive was evaluated by the following method. First, the film adhesive 60 μm of the adhesive sheet obtained above was attached to a semiconductor wafer having a thickness of 50 μm at 70 ° C. Next, they were diced to 7.5 mm square to obtain a semiconductor element (chip) 13b to which the film adhesive 1 was adhered. Subsequently, as shown in FIG. 7, the film-like adhesive 1 of the separated semiconductor element 13 b was pressure-bonded to the evaluation substrate 300 under the conditions of 120 ° C., 0.10 MPa, and 1 second to obtain a sample 400.

  Subsequently, the obtained sample was heated at 140 ° C. for 30 minutes, and a thermal history (150 ° C., 1 hour) equivalent to wire bonding was given to the sample using a hot plate. Next, using a mold sealing material (manufactured by Hitachi Chemical Co., Ltd., trade name “CEL-9750ZHF10), resin sealing was performed under the conditions of 175 ° C./6.7 MPa / 90 seconds, and 175 ° C. for 5 hours. The sealing material was cured under conditions to obtain a package.

  Twenty-four packages described above were prepared, and these were exposed to the environment (level 3, 30 ° C., 60 RH%, 192 hours) determined by JEDEC to absorb moisture. Subsequently, the package after moisture absorption was passed through an IR reflow furnace (260 ° C., maximum temperature 265 ° C.) three times. A case where no breakage of the package or a change in thickness, no peeling at the interface between the film adhesive and the semiconductor element was observed was evaluated as “A”, and a case where even one was observed was evaluated as “B”. . The evaluation results are shown in Table 2.

  As is apparent from the results shown in Table 2, in Examples 1 to 3, the wire embeddability is superior to that of Comparative Examples 1 and 2, and the process is continued by performing a heat treatment at 140 ° C./30 minutes. Foaming is suppressed by heat (150 ° C), and voids disappear by sealing under a sealing condition of 175 ° C / 6.7 MPa / 90 seconds even after a heat history of 150 ° C / 1 hour or less. It was also confirmed that the reflow resistance was excellent.

  DESCRIPTION OF SYMBOLS 1 ... Film adhesive, 2, 7 ... Base film, 13, 13a, 13b ... Semiconductor element, 17 ... Support member, 23 ... Wire, 100, 110, 120 ... Adhesive sheet, 200, 210 ... Semiconductor device.

Claims (6)

A film adhesive containing an epoxy resin and a phenol resin,
(A1) at least one of an epoxy resin having a softening point of 85 ° C. or higher and an epoxy equivalent of 500 or higher, and a phenol resin having a softening point of 85 ° C. or higher and a hydroxyl group equivalent of 500 or higher, (a2) At least one of an epoxy resin having a softening point of 85 ° C. or more and an epoxy equivalent of 150 or less, and a phenol resin having a softening point of 85 ° C. or more and a hydroxyl equivalent of 150 or less, and (a3) a softening point A thermosetting component containing at least one of an epoxy resin and a phenolic resin that is 75 ° C. or less,
(B) a high molecular weight component having a crosslinkable functional group in a monomer ratio of 3 to 15%, a weight average molecular weight of 100,000 to 1,000,000 and a glass transition temperature of −50 to 50 ° C .;
(C) an inorganic filler,
The content of the component (a1) is 10 to 40 parts by mass based on 100 parts by mass of the thermosetting component,
The content of the component (a2) is 5 to 20 parts by mass based on 100 parts by mass of the thermosetting component,
The content of the component (a3) is 25 to 55 parts by mass based on 100 parts by mass of the thermosetting component,
The content of the high molecular weight component is 20 to 100 parts by mass based on 100 parts by mass of the thermosetting component,
The film adhesive whose content of the said inorganic filler is 10-80 mass parts on the basis of 100 mass parts of said thermosetting components.   The film adhesive of Claim 1 whose content of a hardening accelerator is 0.07 mass part or less on the basis of 100 mass parts of said thermosetting components. The film adhesive is thermosetting,
The shear viscosity at 80 ° C. is 200 to 11000 Pa · s,
The tensile elastic modulus at 150 ° C. when heated at 140 ° C. for 30 minutes is 0.01 MPa or more,
The film adhesive according to claim 1 or 2, wherein the tensile elastic modulus at 175 ° C when heated at 140 ° C for 30 minutes and then heated at 150 ° C for 1 hour is 20 MPa or less.   The film adhesive as described in any one of Claims 1-3 whose adhesive strength after hardening with respect to a SiN film | membrane is 1.0 Mpa or more.   An adhesive sheet provided with a base film and the film adhesive as described in any one of Claims 1-4 arrange | positioned on the said base film. Crimping which crimps | bonds a semiconductor element and a supporting member on the conditions of 80-140 degreeC, 0.01-0.50 MPa, 1-5 second through the film adhesive as described in any one of Claims 1-4. Process,
After the pressure bonding step, a first heating step of heating the film adhesive at 120 to 150 ° C. for 15 to 60 minutes,
After the first heating step, a second heating step of connecting the semiconductor element and the support member with a wire by heating at 150 ° C. or less for 1 hour or less,
After the second heating step, a sealing step of resin-sealing the semiconductor element under conditions of 170 to 185 ° C., 4.5 to 8.0 MPa, and 60 to 180 seconds, a method for manufacturing a semiconductor device .