JP4778078B2 - Adhesive composition, adhesive sheet, dicing die attach film, and semiconductor device - Google Patents

Description

  The present invention relates to an adhesive composition containing a (meth) acrylic resin, an epoxy resin, and an aromatic polyamine, and capable of reducing the occurrence of voids when bonding a semiconductor chip to a substrate, and the adhesive composition. The present invention relates to an adhesive sheet and a dicing die attach film used, and a semiconductor device obtained by using the adhesive sheet or the dicing die attach film.

  For example, (i) a large-diameter silicon wafer on which an IC circuit is formed is cut into semiconductor chips in a dicing (cutting) process, and (ii) the chip is lead with a curable liquid adhesive or the like as a die bond material. The chip is fixed (mounted) by thermocompression bonding to the frame, and the adhesive is cured. (Iii) After wire bonding between the electrodes, (iv) To improve handling and protect from the external environment, sealing is performed. Manufactured by stopping. As a form of sealing, a transfer molding method using a resin is most commonly used because it is excellent in mass productivity and inexpensive.

  2. Description of the Related Art In recent years, with the enhancement of functions of semiconductor devices, a support substrate (base material) for mounting a semiconductor chip is also required to have high density and miniaturization. In such a situation, when a liquid adhesive is used as the die bond material, the adhesive tends to protrude from the end of the chip when the semiconductor chip is mounted, and the electrode is easily contaminated. Inclination tends to cause wire bonding defects. Therefore, in order to improve these drawbacks, it is desired to form an adhesive film.

  On the other hand, the substrate has uneven portions due to circuit elements such as wiring, and when the semiconductor chip is thermocompression bonded to such a substrate, the adhesive film as the die bond material, that is, the die bond film completely fills the recess. Otherwise, the unfilled portion remains as a void, which expands upon heating in the reflow furnace, and may damage the adhesive layer and impair the reliability of the semiconductor device. In particular, in recent years, reflow resistance is required at a high temperature (265 ° C.) corresponding to lead-free solder, and the importance of preventing the formation of voids is increasing. Hereinafter, the performance of filling the recesses on the substrate without leaving voids is referred to as “embedding performance”.

  In order to solve the above problem, the semiconductor chip is thermocompression bonded to the substrate with a die bond film having a low melt viscosity so that the melted die bond film enters and fills the recesses existing on the substrate, so that voids are not formed as much as possible. A method is conceivable. However, this method cannot completely eliminate the formation of voids, and may require a high pressure or both for a long time for thermocompression bonding, which may adversely affect productivity. Furthermore, the die bond film may protrude greatly from the chip end and contaminate the electrode.

  As another method for solving the above problem, since the molding with the sealing resin is performed at a high temperature and high pressure, the remaining void is heated and compressed in the resin sealing step to reduce the volume of the void. Further, there is a method of removing the voids by absorbing in the die bond film or by heat curing the die bond film while reducing the volume of the voids. This method does not require a special process and is advantageous in terms of manufacturing.

  By the way, conventionally, as the above-mentioned adhesive for die bonding, specifically, a low elastic modulus material including an acrylic resin, an epoxy resin, which is a resin having excellent adhesiveness, a phenol resin, which is a curing agent thereof, and a catalyst has been developed. (For example, Patent Documents 1 to 3). However, although these adhesives are excellent in adhesiveness, the adhesive film using the adhesive has a fast curing reaction, so when applied to the above method of removing voids in the resin sealing step, the resin sealing step Since the rate of increase in film melt viscosity is increased by heating in the previous wire bonding step, it is difficult to remove voids in the resin sealing step. That is, as a result of an increase in melt viscosity, the void volume cannot be sufficiently reduced, and the void cannot be absorbed into the resin. Therefore, it is difficult to sufficiently fill the concave portion on the substrate with the conventional adhesive, and improvement of the filling performance is required.

  In a dicing die attach film in which an adhesive film made of an adhesive containing an epoxy resin is laminated on the pressure-sensitive adhesive layer of the dicing film, depending on the selection of one or both of the epoxy resin and the epoxy resin curing agent, These components may migrate to a dicing film over time. As a result, the characteristics (adhesiveness, embedding performance) of the adhesive film change over time after manufacturing the dicing die attach film, and the semiconductor obtained by storing the dicing die attach film for a long period of time and used for manufacturing the semiconductor device Since the device is inferior in reliability, it is difficult to ensure the storage stability of the dicing die attach film in the manufacturing process of the semiconductor device.

  In addition, the adhesive film made of an adhesive containing an epoxy resin, depending on the epoxy resin, increases the rate of increase in melt viscosity and the modulus of elasticity due to heating in the wire bonding process, making it difficult to remove voids in the resin sealing process. It may become.

JP-A-10-163391 Japanese Patent Laid-Open No. 11-12545 JP 2000-154361 A

  The present invention provides an adhesive composition that not only has excellent adhesiveness but also has excellent embedding performance and provides a highly reliable semiconductor device when used in the manufacture of a semiconductor device, and an adhesive sheet using the adhesive composition An object of the present invention is to provide a dicing die attach film excellent in characteristic stability and pickup stability using the adhesive composition, and a semiconductor device obtained using the adhesive sheet or the dicing die attach film. And

  Therefore, the present inventors have made various studies on an adhesive composition containing a (meth) acrylic resin and an epoxy resin, and the above-described adhesive composition, adhesive sheet, dicing die attach film, and semiconductor device described above. The inventors have found that the object can be achieved and completed the present invention.

That is, the present invention firstly
(A) The weight average molecular weight is 50,000 to 1,500,000, the epoxy group and the following formula (1):

（１）

で表される構造単位を有する（メタ）アクリル系樹脂、
（Ｂ）ジシクロペンタジエン骨格構造を有するエポキシ樹脂、ならびに
（Ｃ）ジフェニルスルホン骨格構造を有する芳香族ポリアミン
を含む接着剤組成物を提供する。

(1)

(Meth) acrylic resin having a structural unit represented by
Provided is an adhesive composition comprising (B) an epoxy resin having a dicyclopentadiene skeleton structure, and (C) an aromatic polyamine having a diphenylsulfone skeleton structure.

  The present invention secondly provides an adhesive sheet comprising a base material and an adhesive layer made of the adhesive composition provided on the base material. In addition, the adhesive bond layer which consists of this adhesive composition maintains a film shape at room temperature even in the state peeled from the base material, and corresponds to what is called an adhesive film.

  Thirdly, the present invention provides a dicing film having a base material and a pressure-sensitive adhesive layer provided thereon, and an adhesive layer comprising the above-mentioned adhesive composition provided on the pressure-sensitive adhesive layer of the dicing film. Provided with a dicing die attach film.

  Fourth, the present invention provides a semiconductor device manufactured using the adhesive sheet or the dicing die attach film.

  The adhesive composition of the present invention has an increase in melt viscosity due to heating in the wire bonding process, and has a melt viscosity that can sufficiently eliminate voids in the resin sealing process. Since voids can be extracted sufficiently, it has excellent embedding performance. Further, a cured product obtained by heating and curing the adhesive composition in layers, that is, an adhesive cured product layer, has a high adhesive force with respect to various substrates, has a low elastic modulus, and is excellent in heat resistance. . Furthermore, the dicing die attach film of the present invention is excellent in characteristic stability and pickup stability even after being stored for a long period of time, so that it maintains a stable characteristic for a long period in the manufacturing process of the semiconductor device. It can be used suitably. Therefore, the adhesive composition of the present invention, and the adhesive sheet and dicing die attach film using the adhesive composition are useful for manufacturing a highly reliable semiconductor device.

It is a figure which shows arrangement | positioning of the silicon chip in an embedding performance test.

  Hereinafter, the present invention will be described in detail. In the present specification, “weight average molecular weight” refers to a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

  Since the adhesive composition of the present invention contains the above components (A) to (C) and maintains the shape at room temperature, for example, a film-like thin film can be formed, and on the other hand, it becomes a plastic state by heating, and further Exhibits excellent embedding performance by maintaining the state for a long time. The cured product of the composition has high adhesion to the substrate, a low elastic modulus, and excellent heat resistance.

  The dicing die attach film in which the adhesive layer made of the adhesive composition of the present invention is laminated on the pressure-sensitive adhesive layer of the dicing film has a component from the adhesive layer to the dicing film even after being stored for a long time. Since the transition is suppressed and the characteristic stability and pickup stability are excellent, stable characteristics can be maintained over a long period in the manufacturing process of the semiconductor device.

[Adhesive composition components]
<(A) (Meth) acrylic resin>
The component (A) has a weight average molecular weight of 50,000 to 1,500,000, an epoxy group and the following formula (1):

（１）

で表されるアクリロニトリル由来の構造単位を有する（メタ）アクリル系樹脂である。本明細書において（メタ）アクリル系樹脂とは、アクリル酸、アクリル酸誘導体、メタクリル酸およびメタクリル酸誘導体からなる（メタ）アクリル系単量体に由来する構造単位を含む重合体をいう。（Ａ）成分は、一種単独で使用しても二種以上を組み合わせて使用してもよい。二種以上を組み合わせて使用する場合、（Ａ）成分は、エポキシ基を有する（メタ）アクリル系樹脂とエポキシ基を有しない（メタ）アクリル系樹脂との混合物であってもよい。

(1)

(Meth) acrylic resin having a structural unit derived from acrylonitrile represented by the formula: In this specification, the (meth) acrylic resin refers to a polymer containing a structural unit derived from a (meth) acrylic monomer composed of acrylic acid, an acrylic acid derivative, methacrylic acid and a methacrylic acid derivative. (A) A component may be used individually by 1 type, or may be used in combination of 2 or more type. When using in combination of 2 or more types, the (A) component may be a mixture of a (meth) acrylic resin having an epoxy group and a (meth) acrylic resin having no epoxy group.

  The component (A) is, for example, a homopolymer or copolymer of the above (meth) acrylic monomer or a copolymer of the (meth) acrylic monomer and other monomers. And a polymer having a weight average molecular weight of 50,000 to 1,500,000 and having an epoxy group and a structural unit represented by the above formula (1). In the copolymer of the (meth) acrylic monomer and the other monomer, the content of the structural unit derived from the other monomer is preferably 0 to 0 in all the structural units of the component (A). It is 50 mol%, More preferably, it is 0-30 mol%. In the copolymer of (meth) acrylic monomers and other monomers, these monomers may be used alone or in combination of two or more.

  Examples of the acrylic acid derivative include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate and butyl acrylate; acrylic acid amides such as dimethyl acrylic acid amide; epoxy group-containing acrylic acid esters such as glycidyl acrylate; acrylonitrile Is mentioned.

  Examples of the methacrylic acid derivatives include methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; methacrylic acid amides such as dimethyl methacrylate amide; and epoxy group-containing methacrylates such as glycidyl methacrylate. It is done.

  Examples of the other monomers include styrene, butadiene, and allyl derivatives (allyl alcohol, allyl acetate, etc.).

  (A) A component has an epoxy group from the adhesive point of the adhesive agent hardened | cured material layer obtained. This epoxy group reacts with the (B) and (C) components. For example, the epoxy group is introduced into the component (A) by synthesizing the component (A) using a monomer containing an epoxy group as a part of the monomer used as the raw material of the component (A). can do. Examples of the monomer containing an epoxy group include an acrylic acid derivative containing an epoxy group and a methacrylic acid derivative containing an epoxy group, and more specifically, an epoxy group-containing acrylic acid such as glycidyl acrylate. An epoxy group-containing methacrylate such as an ester or glycidyl methacrylate is exemplified.

  The content of the epoxy group in the component (A) is preferably 0.002 to 0.1 mol, more preferably 0.005 to 0.05 mol, per 100 g of the component (A). When the content is in the range of 0.002 to 0.1 mol, a composition having sufficient embedding performance and a cured adhesive layer having sufficient adhesive strength can be easily obtained.

  The structural unit represented by the above formula (1) is obtained by synthesizing the component (A) using acrylonitrile as a part of the monomer used as the raw material of the component (A), for example, in the component (A) Can be introduced. In the component (A), the content of the structural unit derived from acrylonitrile (ratio of acrylonitrile in all monomers to be copolymerized) is preferably 5 to 50% by mass, particularly 10 to 40% by mass. preferable.

  The weight average molecular weight of the component (A) is usually 50,000 to 1,500,000, preferably 100,000 to 1,000,000. If the molecular weight is less than 50,000, the adhesiveness and strength of the resulting cured adhesive layer may be reduced. If the molecular weight exceeds 1,500,000, the resulting composition may be too viscous to be handled.

  In addition, the (meth) acrylic resin of component (A) preferably has a glass transition point (Tg) measured by thermomechanical analysis (TMA) of −40 ° C. to 100 ° C., more preferably −10 to 70. ° C.

<(B) Epoxy resin>
The component (B) is an epoxy resin having a dicyclopentadiene skeleton structure, and preferably has at least two epoxy groups in one molecule. Component (B) can be used alone or in combination of two or more.

  In the present specification, the “dicyclopentadiene skeleton structure” means the following formula:

で表される構造、および、上記式で表される構造から一部または全部の水素原子を除いた残りの構造をいう。後者の構造において、除かれる水素原子の数および位置に制限はない。中でも、上記式で表される構造が好ましい。

And the remaining structure obtained by removing some or all of the hydrogen atoms from the structure represented by the above formula. In the latter structure, there is no limit to the number and position of hydrogen atoms removed. Among these, the structure represented by the above formula is preferable.

  In general, an adhesive layer made of an adhesive composition containing an epoxy resin having a high content of low molecular weight substances (mainly compounds having two epoxy groups in one molecule) is laminated on the pressure-sensitive adhesive layer of the dicing film. In the dicing die attach film, the epoxy resin in the adhesive layer easily moves into the dicing film. As a result, in the adhesive layer, the component balance of the composition is lost, the cross-linking density between the resins decreases, and the adhesiveness of the adhesive layer may deteriorate with time. In addition, a semiconductor device obtained using the adhesive layer after long-term storage may be inferior in reliability. Specifically, the above phenomenon occurs when an epoxy resin having a higher crystalline skeleton in the molecule, such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenyl type epoxy resin, or a naphthalene type epoxy resin is used. Likely to happen. At this time, the low molecular weight substance of the epoxy resin moves from the adhesive layer into the dicing film. A dicing die attach film in which an adhesive layer made of an adhesive composition containing an epoxy resin having a higher skeleton in the molecule is laminated on the pressure-sensitive adhesive layer of the dicing film at 25 ° C. for one month from the production. The amount of components in the adhesive layer that migrate from the adhesive layer to the dicing film when allowed to stand at 50% RH is the total amount of components in the adhesive layer of the dicing die attach film before standing. It reaches 30% by mass or more. Therefore, after standing, even if the adhesive layer is cured, the crosslinking density is lowered, which is not preferable. Further, as the epoxy resin moves, the adhesive force between the dicing film and the adhesive layer increases with time, and it becomes difficult to take out (pick up) the separated chips.

  On the other hand, when an epoxy resin having a lower crystalline skeleton such as a dicyclopentadiene type epoxy resin, a cresol novolac type epoxy resin, a phenol novolac type epoxy resin, or a zylock type epoxy resin is used as an epoxy resin, There are advantages. That is, a dicing die attach film obtained by laminating an adhesive layer made of an adhesive composition containing such an epoxy resin on the pressure-sensitive adhesive layer of the dicing film was allowed to stand at 25 ° C. and 50% RH for one month from the production. The amount of the component in the adhesive layer that is sometimes transferred from the adhesive layer to the dicing film is suppressed to less than 30% by mass of the total component in the adhesive layer of the dicing die attach film before standing. It can suppress that the adhesiveness of this adhesive bond layer falls over time. Furthermore, even when the adhesive layer after long-term storage is used, a semiconductor device having excellent reliability can be obtained.

  Therefore, the adhesive sheet comprising the adhesive composition containing the epoxy resin having the dicyclopentadiene skeleton structure as the component (B) has excellent long-term stability and high adhesiveness, and the adhesive sheet is used. The semiconductor device obtained in this way has excellent reliability. Therefore, the adhesive sheet can be suitably applied to a dicing die attach film in a semiconductor device manufacturing process.

  The component (B) is not particularly limited as long as it has a dicyclopentadiene skeleton structure. When the adhesive composition of the present invention is applied as an adhesive sheet, particularly when the silicon wafer to be attached is thin, the adhesive sheet can be pressed at a lower temperature and a lower pressure in order to prevent the occurrence of cracks and warpage. Moreover, it is preferable that (B) component is solid at room temperature, and the softening temperature measured by the ring and ball method (JIS-K7234) is 100 degrees C or less. The amount of the low molecular weight substance present in the epoxy resin of component (B) is not too much, and the resulting adhesive sheet is less likely to exhibit tack, and the resulting dicing die attach film is a chip after dicing Can be easily taken out (pick up).

  The component (B) is preferably the following structural formula (2):

（２）

（式中、ｎは０以上の数である。）
で示されるエポキシ樹脂が例示される。上記構造式（２）中、ｎは０以上の数であるが、好ましくは０〜１０の数、より好ましくは０〜５の数である。このエポキシ樹脂は、１分子中にエポキシ基を少なくとも２個有する化合物である。上記構造式（２）で示されるエポキシ樹脂は、１種単独でも２種以上を組み合わせても使用することができる。

(2)

(In the formula, n is a number of 0 or more.)
The epoxy resin shown by is illustrated. In the structural formula (2), n is a number of 0 or more, preferably a number of 0 to 10, more preferably a number of 0 to 5. This epoxy resin is a compound having at least two epoxy groups in one molecule. The epoxy resin represented by the structural formula (2) can be used alone or in combination of two or more.

  When the epoxy resin represented by the structural formula (2) is used in the adhesive composition of the present invention and the adhesive composition is applied to a dicing die attach film, the amount of components transferred from the adhesive layer to the dicing film The increase in melt viscosity and elastic modulus of the adhesive layer can be suppressed more effectively even after heating in the wire bonding process, and the embedding performance is further improved.

  (B) The compounding quantity of a component becomes like this. Preferably it is 5-300 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 10-200 mass parts. When the blending amount is in the range of 5 to 300 parts by mass, an adhesive composition having sufficient embedding performance can be easily obtained, and the obtained cured adhesive layer is excellent in adhesiveness and elastic modulus. Rise is suppressed, and it tends to have sufficient flexibility.

<(C) Aromatic polyamine>
The aromatic polyamine having a diphenylsulfone skeleton structure as the component (C) is a compound having a diphenylsulfone skeleton structure and having at least two amino groups directly bonded to an aromatic ring, a curing agent for an epoxy resin and a catalyst It has the function as. The aromatic polyamine of component (C) has a benzene ring in the diphenylsulfone skeleton structure, but may further have another aromatic ring. When the aromatic ring in component (C) is only the benzene ring in the diphenylsulfone skeleton structure, at least two amino groups are directly connected to the benzene ring, and the aromatic ring in component (C) is diphenylsulfone skeleton. When it is a benzene ring in the structure and an aromatic ring other than the benzene ring, it is directly connected to one or both of the benzene ring and the aromatic ring other than the benzene ring.

  The aromatic polyamine (C) has a melting point exceeding 170 ° C., and has low reactivity under heating in the wire bonding step. Therefore, the curing reaction proceeds slowly in the composition containing the component (C). For this reason, in this composition, the raise of the melt viscosity by heat curing can be suppressed effectively. In addition, a cured product obtained by heat-curing a composition containing the aromatic polyamine (C) has excellent heat resistance. Therefore, the composition of the present invention containing the aromatic polyamine of component (C) is likely to have improved embedding performance and excellent heat resistance after curing as compared with the conventional composition. Component (C) can be used alone or in combination of two or more.

  In the present specification, the “diphenylsulfone skeleton structure” refers to the remaining structure obtained by removing some or all of the hydrogen atoms from diphenylsulfone, and there is no limitation on the number and position of hydrogen atoms to be removed. Among them, the following structural formula:

で示されるジフェニルスルホン骨格構造が好ましい。

The diphenylsulfone skeleton structure shown by these is preferable.

  When the component (C) has a benzene ring in the diphenylsulfone skeleton structure and an aromatic ring other than the benzene ring, the aromatic ring other than the benzene ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Also good. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. As an aromatic heterocyclic ring, a pyridine ring, a quinoline ring, an isoquinoline ring etc. are mentioned, for example.

  Specific examples of the component (C) include 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-amino And phenoxy) phenyl) sulfone. Among these, 4,4′-diaminodiphenyl sulfone and 3,3′-diaminodiphenyl sulfone can be preferably used industrially. These aromatic polyamines are known as epoxy resin curing agents, and commercially available products can be used.

  The amount of component (C) is preferably such that the molar ratio of amino groups in component (C) to all epoxy groups in the composition of the present invention is 0.6 to 1.4, 0.8 More preferably, the amount is -1.2. When the component (C) in an amount such that the molar ratio is 0.6 to 1.4 is added to the composition of the present invention, the composition is sufficiently cross-linked, and the resulting cured product has good curing characteristics. The adhesion and the solder reflow resistance are effectively improved. In addition, the component (C) is less likely to remain as an unreacted product in the cured product and is not easily wasted. Therefore, it is easy to save resources and is economical.

  In addition to the epoxy resin of the component (B), the composition of the present invention can contain the component (A) and other components containing an epoxy group as components containing an epoxy group. The total epoxy group in the composition of the present invention means the total of the epoxy group in the component (B), the epoxy group in the component (A), and the epoxy group in the other components containing the epoxy group. . The total molar ratio of the epoxy groups in the component (B) and the epoxy groups in the component (A) to the total epoxy groups in the composition of the present invention is preferably 0.5 to 1.0, more preferably 0.7. -1.0. Moreover, the molar ratio of the epoxy group in the component (B) to all epoxy groups in the composition of the present invention is preferably 0.5 to 1.0, more preferably 0.6 to 0.9. Here, when a component having an epoxy group other than the component (B) and the component (A) is not included in the composition of the present invention, the blending amount of the component (C) is an epoxy group in the component (B). And the molar ratio of the amino group in the component (C) to the total of the epoxy groups in the component (A) is preferably 0.6 to 1.4, and preferably 0.8 to 1.2. More preferred is an amount.

<Other ingredients>
In addition to the above components (A) to (C), other components may be added to the adhesive composition of the present invention as long as the properties of the composition are not impaired. Other components include, for example, epoxy resins other than the component (B); curing agents and catalysts for epoxy resins other than the component (C); fillers; adhesion assistants; colorants such as pigments and dyes; Antioxidants; heat stabilizers; solvents and the like.

-Epoxy resin other than component (B) In the composition of the present invention, an epoxy resin having a skeleton structure other than the dicyclopentadiene skeleton structure may be used in combination with the epoxy resin of component (B). Such epoxy resins other than the component (B) are known and commercially available products can be used. Examples of the epoxy resin other than the component (B) include, for example, bisphenol F type epoxy resin; bisphenol A type epoxy resin; novolak type epoxy resin obtained by condensing novolac type phenol resin such as phenol novolak and cresol novolak and epichlorohydrin; Naphthalene ring-containing epoxy resin; biphenyl type epoxy resin; phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin. Preferably it is a novolac type epoxy resin. (B) The compounding quantity of epoxy resins other than a component is 0-50 mass parts with respect to 100 mass parts of (B) component, Preferably it is 0-20 mass parts. If the blending amount exceeds 50 parts by mass, the embedding performance of the resulting adhesive composition may be impaired.

-Curing agent and catalyst for epoxy resins other than component (C) Examples of the curing agent and catalyst for epoxy resins other than component (C) include phenolic compounds known as curing agents or catalysts for epoxy resins. The amount of the epoxy resin curing agent and the catalyst other than the component (C) is such that the effect of the aromatic polyamine of the component (C) is not hindered.

-Filler You may mix | blend a filler with this invention composition. There is no restriction | limiting in particular in a filler, A well-known thing can be used. A filler may be used individually by 1 type, or may be used in combination of 2 or more type. The blending amount of the filler is preferably 0 to 900 parts by mass, more preferably 0 to 500 parts by mass with respect to 100 parts by mass in total of the components (A) to (C).

  Examples of the filler include inorganic fillers such as silica particles, alumina, titanium oxide, carbon black, and other conductive particles such as silver particles; and organic fillers. Among these, silica particles are preferable. Hereinafter, the silica particles will be described in more detail.

  Silica particles moderately increase the melt viscosity of the adhesive layer made of the adhesive composition of the present invention, suppress the chip flow in the resin sealing step, and the moisture absorption rate and linear expansion of the resulting cured adhesive layer Reduce the rate. There is no restriction | limiting in particular in a silica particle, A well-known thing can be used. The silica particles are preferably surface-treated with an organosilicon compound such as organoalkoxysilane, organochlorosilane, organosilazane, and low molecular weight siloxane from the viewpoint of the fluidity of the resulting composition. Silica particles may be used alone or in combination of two or more.

  The average particle diameter of the silica particles is preferably 10 μm or less, more preferably 5 μm or less. When the average particle size is 10 μm or less, the adhesive sheet of the present invention can easily maintain the smoothness of the surface. The maximum particle size of the silica particles is preferably 20 μm or less. In the present specification, the “average particle size” means a volume-based average particle size corresponding to 50% of the cumulative distribution obtained by a particle size distribution measuring apparatus using a laser light diffraction method. The “maximum particle size” is the maximum value of the particle size in the cumulative distribution measured when the average particle size is obtained as described above.

  Examples of the silica particles include reinforcing silica such as fumed silica and precipitated silica; and crystalline silica such as quartz. Specifically, Aerosil R972, R974, R976 manufactured by Nippon Aerosil Co., Ltd .; SE-2050, SC-2050, SE-1050, SO-E1, SO-C1, SO-E2, SO manufactured by Admatechs Co., Ltd. -C2, SO-E3, SO-C3, SO-E5, SO-C5; Musil 120A and Musil 130A manufactured by Shin-Etsu Chemical Co., Ltd. are exemplified.

  The blending amount of the silica particles is preferably 5 to 80% by weight, particularly preferably 10 to 60% by weight, based on the total weight of the composition while adjusting the blending amount of the entire filler within the above range. . When the blending amount is in the range of 5 to 80% by mass, the obtained cured adhesive layer can effectively reduce the moisture absorption rate and the linear expansion coefficient, and easily suppress the increase in the elastic modulus. .

-Adhesion aid In order to improve adhesiveness, you may add an adhesion aid to the composition of this invention. The adhesion assistant can be used alone or in combination of two or more. As an adhesion assistant, for example, a coupling agent (silane coupling agent) containing silicon can be used. Examples of adhesion aids include epoxy group-containing silane coupling agents, mercapto group-containing silane coupling agents, amino group-containing silane coupling agents, (meth) acrylic group-containing silane coupling agents, etc. KBM-403, KBM-402, KBM-803, KBM-802, KBM-903, KBM-902, KBM-503, KBM5103 or X-12-414, or a partial hydrolyzate thereof, manufactured by Shin-Etsu Chemical Co., Ltd. Can be mentioned.

-Solvent You may add a solvent to the composition of this invention from viewpoints of the ease of mixing of each component, the ease of application | coating of the composition obtained, etc. The solvent can be used alone or in combination of two or more. Examples of the solvent include aprotic polar solvents such as methyl ethyl ketone, toluene, ethyl acetate, cyclohexanone, and N-methylpyrrolidone (NMP).

[Preparation of adhesive composition]
The adhesive composition of the present invention can be prepared by mixing the above components (A) to (C) and optionally other components at room temperature by conventional mixing means.

[Use of adhesive composition]
The adhesive composition of the present invention can be used, for example, to bond two adherends. Although these adherends are not particularly limited, examples of one adherend include silicon chips, glass, and ceramics, and examples of the other adherend include resin substrates such as a BT substrate; gold Lead frame substrate made of silver, copper, nickel, etc .; silicon substrate.

  For example, the adhesive composition of the present invention is dissolved in a solvent at an appropriate concentration, applied onto one adherend, dried, and then applied to the adherend surface to which the adhesive composition has been applied. These two adherends can be bonded together by pressure-bonding the adherends and heat-curing the adhesive composition. Examples of the solvent are the same as described above. Drying is preferably performed at room temperature to 200 ° C., particularly 80 to 150 ° C. for 1 minute to 1 hour, particularly 3 to 10 minutes. The pressure bonding is preferably performed at a pressure of 0.01 to 10 MPa, particularly 0.05 to 2 MPa. The heat curing is preferably performed at a temperature of 100 to 200 ° C., particularly 120 to 180 ° C., for 30 minutes to 8 hours, particularly 1 to 7 hours.

  Moreover, the adhesive composition of this invention can also be used for adhere | attaching two to-be-adhered bodies in the state shape | molded in the film form. For example, the two adherends can also be bonded using a bonding sheet including a substrate and an adhesive layer made of the adhesive composition of the present invention provided on the substrate. More specifically, for example, the adhesive layer is peeled off from the adhesive sheet, and the adhesive layer is sandwiched between two adherends in a layered manner and heat-cured and heat-cured. The body can also be glued. The conditions for pressure bonding and heat curing are the same as described above.

  The adhesive sheet can be obtained by dissolving the adhesive composition of the present invention in a solvent at an appropriate concentration in the same manner as described above, applying the solution onto a substrate and drying it to form an adhesive layer. Examples of the solvent and drying conditions are the same as described above. There is no restriction | limiting in particular in the film thickness of an adhesive bond layer, Although it can select according to the objective, It is preferable that it is 10-100 micrometers, and it is especially preferable that it is 15-50 micrometers. The substrate is usually in the form of a film, for example, polyethylene film, polypropylene film, polyester film, polyamide film, polyimide film, polyamideimide film, polyetherimide film, polytetrafluoroethylene film, paper, metal foil, etc. The base material or the base material whose surface has been subjected to mold release treatment can be used. The thickness of the substrate is preferably 10 to 100 μm, more preferably 25 to 50 μm.

  In the field of semiconductor device manufacturing, an adhesive layer (adhesive film) made of an adhesive composition can be used as a so-called die bond film for bonding a silicon chip to a substrate. When a semiconductor device is manufactured through a wire bonding process and a sealing process after the silicon chip is die-bonded to the substrate using the adhesive film, the adhesion obtained by curing the adhesive film in a portion not embedded after the die bonding The adhesive force between the cured agent layer and the substrate is reduced by heating in the wire bonding process. The portion that has not been embedded is embedded by a sealing process after the wire bonding process. In order for the resin-encapsulated semiconductor device to be reliable in this way, even if there is a portion where the adhesive force is reduced between the cured adhesive layer and the substrate, sufficient adhesion is achieved as a whole. It is necessary to hold power. The adhesive force required for this is usually at least 1 MPa when measured at 260 ° C. Therefore, after heating an adhesive film sandwiched between two adherends such as a combination of a silicon chip and a substrate under the heating conditions in the wire bonding process, heating / heating in the sealing process with a semiconductor sealing resin is performed. When the shear adhesive force between the two adherends was measured at 260 ° C. after thermocompression bonding under pressure conditions and further heat-cured to form a layered cured product (adhesive cured product layer), the shear adhesive force Is usually at least 1 MPa. Although there are various heating conditions in the wire bonding process, it is generally 30 minutes or more at 170 ° C. Moreover, the heating / pressurizing conditions in the sealing step with the semiconductor sealing resin are usually 160 to 180 ° C./5 to 10 MPa for 10 to 150 seconds. The conditions for heat curing are as described above.

  The adhesive composition of the present invention can be used for the dicing die attach film of the present invention. That is, the dicing die attach film of the present invention includes a dicing film having a base material and a pressure-sensitive adhesive layer provided thereon, and the adhesive composition of the present invention provided on the pressure-sensitive adhesive layer of the dicing film. A dicing die attach film provided with an adhesive layer comprising:

  The dicing film used in the dicing die attach film of the present invention is preferably composed of at least two layers of a base film-like substrate and an adhesive layer.

  The base material is not particularly limited as long as it is generally used in dicing films. Examples of the base material include (I) homopolymer of α-olefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ionomer, and the like. Heat of polymer or copolymer, (II) engineering plastics such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, (III) polyurethane, styrene-ethylene-butene copolymer, styrene-ethylene-pentene copolymer, etc. A synthetic resin such as a plastic elastomer can be used.

  The thickness of the substrate is preferably 60 to 200 μm. If the thickness of the substrate is in the range of 60 to 200 μm, the amount of epoxy resin transferred from the adhesive layer to the dicing film tends to be suppressed, so that the characteristics of the adhesive layer can be easily maintained. The operation of mounting the wafer on the film is easy, and it is possible to effectively prevent the base material from being fused to the chuck table by the cutting heat during dicing.

  The adhesive layer should just be provided in the at least one surface of the said base material. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is good from a dicing film with a chip obtained by dicing a wafer using the dicing die attach film of the present invention, with the adhesive film attached to the back surface of the chip. The pressure-sensitive adhesive and the ultraviolet (UV) curable adhesive that are used as a normal dicing tape can be used. More specifically, examples of the adhesive include rubber-based, acrylic-based, urethane-based, and silicone-based pressure-sensitive adhesives. Preferably, an acrylic adhesive, a urethane adhesive, or a silicone adhesive is used. It is preferable that the thickness of an adhesive layer is 1-50 micrometers, More preferably, it is 5-10 micrometers. The pressure-sensitive adhesive layer preferably has strong adhesion to the substrate to such an extent that chip skipping does not occur in the dicing process, and the 180-degree peeling force between the pressure-sensitive adhesive layer is 0.01 to 0.7 N / 20 mm. Is more preferable, and 0.1 to 0.4 N / 20 mm is more preferable.

  The dicing die attach film of the present invention can be produced, for example, by laminating the adhesive layer in the adhesive sheet of the present invention on the adhesive layer of the dicing film. It can also be obtained by dissolving the adhesive composition of the present invention in a solvent at a suitable concentration similar to the above, applying the composition onto the pressure-sensitive adhesive layer of the dicing film, and drying to form an adhesive layer. Examples of the solvent, drying conditions, and the thickness of the adhesive layer are the same as described above.

  In the dicing die attach film of the present invention, it is preferable that the components in the adhesive layer are suppressed from transferring from the adhesive layer to the dicing film, and more preferably, the dicing die attach film. The amount of components in the adhesive layer that migrates from the adhesive layer to the dicing film when allowed to stand at 25 ° C. and 50% RH for one month from production is the adhesion of the dicing die attach film before standing It is suppressed to less than 30% by mass of all components in the agent layer. The amount of the component transferred from the adhesive layer to the dicing film is more preferably less than 15% by mass, and even more preferably 10% by mass or less. The migration amount can be adjusted by appropriately selecting the type of component (B), the blending amount, and the like.

  According to a conventional method, a semiconductor device can be produced using the adhesive sheet of the present invention or the dicing die attach film of the present invention. The semiconductor device thus obtained has excellent reliability.

  The adhesive composition of the present invention is used not only in the manufacture of electronic parts such as semiconductor devices, but also in the manufacture of various products including an adhesion process, for example, the manufacture of LED parts, sensors, liquid crystal parts and the like. Can do.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these examples.

[Preparation of adhesive composition]
The following components (A) to (C) and other components are charged in a blending amount (parts by mass) shown in Table 1 into a rotating / revolving mixer (manufactured by Shinky Co., Ltd.), and the total of these components Methyl ethyl ketone, toluene, or cyclohexanone was added so as to have a concentration of 20% by mass and mixed to prepare an adhesive composition.

(A) Component (meth) acrylic resin SG-P3LC Rev. 43: (Meth) acrylic resin (Nagasechem) having an epoxy group and further having a structural unit derived from acrylonitrile represented by the above formula (1) Manufactured by Tex Corporation), containing 0.027 mol / 100 g of epoxy group, Tg = 8 ° C., weight average molecular weight = 850,000

(Meth) acrylic resin other than component (A) SG-708-6: (meth) acrylic resin having a carboxyl group and further having a structural unit derived from acrylonitrile represented by the above formula (1) (Nagase) Chemtex), 0.159 mol / 100 g of carboxyl group, Tg = 4 ° C., weight average molecular weight = 800,000

(B) Component Epoxy Resin HP7200: Dicyclopentadiene type epoxy resin (Dainippon Ink Co., Ltd.), epoxy resin represented by the above structural formula (2) (n = 1.6)

(B) Epoxy resin other than component: EOCN-1020: Cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.)
RE-310S: bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin)

(C) Component aromatic polyamine 4,4′-DDS: 4,4′-diaminodiphenylsulfone (manufactured by Wakayama Seika Co., Ltd.)
3,3′-DDS: 3,3′-diaminodiphenyl sulfone (manufactured by Konishi Chemical)

(C) Aromatic polyamines other than component DDM: 4,4′-diaminodiphenylmethane (Wakayama Seika Co., Ltd.), aromatic polyamine having no diphenylsulfone skeleton structure

(Other components) Filler Silica particles: SC-2050 (manufactured by Admatechs), spherical silica, average particle size 0.5 μm

(Other components) Adhesion aid Coupling agent: X-12-414 (manufactured by Shin-Etsu Chemical Co., Ltd.), mercapto silane coupling agent

[Preparation of adhesive sheet]
Next, the adhesive composition was applied onto a 50 μm thick PET film coated with a fluorine-based silicone release agent, dried by heating at 110 ° C. for 10 minutes, and provided with an adhesive layer having a thickness of about 25 μm. A sheet was produced.

[Production of dicing die attach film]
Further, the adhesive sheet prepared above and one of the dicing films described below are bonded at room temperature so that the adhesive layer of the adhesive sheet and the pressure-sensitive adhesive layer of the dicing film are in contact with each other. A die attach film was prepared.

Dicing film ・ Pressure-sensitive dicing film: SD85TA (manufactured by Denki Kagaku Kogyo Co., Ltd.), thickness 85μm
UV curing type dicing film: UHP-110M3 (manufactured by Denki Kagaku Kogyo Co., Ltd.), thickness 110 μm

[test]
The following tests were performed on the obtained adhesive sheet and dicing die attach film. The results are shown in Table 1.

(1) Initial adhesiveness A silicon wafer having a thickness of 450 μm was diced into 2 mm × 2 mm chips, and the adhesive sheet was thermocompressed at 100 ° C. so that the adhesive layer was in contact with the back surface of the diced wafer. . Next, the adhesive sheet was cut into the same shape as the chip, and the silicon chip with the adhesive sheet was taken out. The PET film was peeled from this silicon chip to obtain a silicon chip with an adhesive layer. Next, on the 10 mm × 10 mm BT substrate or silicon substrate on which resist AUS308 (manufactured by Taiyo Ink Co., Ltd.) has been applied and cured, the obtained silicon chip with an adhesive layer contacts the surface on which the adhesive layer is adhered. Then, it was fixed by thermocompression bonding at 170 ° C. and 0.1 MPa for 2 seconds. Thus, the board | substrate with which the silicon chip was fixed was heated at 175 degreeC for 6 hours, the adhesive bond layer was hardened, and the test piece (adhesion test piece) was produced. Using this adhesion test piece, the shear adhesive force between the adhesive cured product layer and the substrate was measured at 260 ° C. with a bond tester (manufactured by DAGE, 4000PXY).

(2) Adhesiveness after moist heat After holding the adhesive test piece of (1) above for 168 hours under the condition of 85 ° C./60% RH and then passing it through a reflow oven at 260 ° C. three times, the above (1) and Similarly, the shear adhesive strength was measured at 260 ° C.

(3) Embedding performance An adhesive sheet was thermocompressed at 70 ° C. so that the adhesive layer was in contact with one surface of a silicon wafer having a diameter of 8 inches and a thickness of 75 μm. A pressure-sensitive dicing film was attached to the adhesive layer surface of the wafer with the adhesive layer obtained by peeling the PET film from the thermobonded adhesive sheet so that the pressure-sensitive adhesive layer of the pressure-sensitive dicing film was in contact. This silicon wafer was diced into 9 mm square silicon chips under the following dicing conditions. Next, the 9 mm square silicon chip thus obtained was peeled from the pressure-sensitive adhesive layer of the pressure-sensitive dicing film with the adhesive layer attached to the back surface. This silicon chip was applied and cured by a die bonder device (BESTEM-D02-TypeB) manufactured by NEC Machinery Co., Ltd. with a resin substrate (resist AUS308 of 50 mm × 50 mm × 250 μm in thickness) on which a 5-15 μm wide stripe circuit pattern was formed. The adhesive layer was placed on the BT substrate), and was thermocompression bonded for 1 second at 130 ° C. and 0.1 MPa. This point will be described in detail with reference to FIG. 1 (a diagram showing the arrangement of silicon chips in the embedding performance test). 16 pieces are arranged in 4 rows and 4 columns at intervals of 3 mm, and the distance between the outermost silicon chip 1 and the outer edge of the resin substrate 2 is 2.5 mm. After heating the resin substrate on which the silicon chip is thermocompression bonded at 170 ° C. corresponding to the heating temperature in the wire bonding step for 120 minutes, the molding material KMC2500LM1B (Shin-Etsu Chemical Co., Ltd.) is formed with a thickness of 600 μm from the resin substrate. The resin was sealed with resin (175 ° C., sealing pressure 6.9 MPa, 90 seconds), and the molding material was heated and cured at 175 ° C. for 4 hours. The inside of the semiconductor package thus obtained was observed with an ultrasonic image measuring device to examine the presence or absence of voids.

  When voids were not confirmed inside the semiconductor package by observation with an ultrasonic image measuring apparatus, it was evaluated that the embedding performance was sufficient. On the other hand, when a void was confirmed inside the semiconductor package by observation with an ultrasonic image measuring apparatus, it was evaluated that the embedding performance was insufficient. In Table 1, “◯” represents that the embedding performance was sufficient, and “x” represents that the embedding performance was insufficient.

(4) Package Reliability The silicon chip sealed with resin in (3) above was cut off, and a total of 16 obtained packages were held for 168 hours under the condition of 85 ° C./60% RH, and then the maximum temperature reached 260 After passing through a solder reflow furnace at 3 ° C. three times, the presence or absence of peeling between the silicon chip and the substrate was observed with an ultrasonic image measuring device. In Table 1, “◯” represents that no peeling was observed in any of the 16 packages, and “X” represents that peeling was observed in any one of the 16 packages.

(5) Transfer amount of epoxy resin in dicing die attach film After storing the dicing die attach film prepared above in a constant temperature and humidity room of 25 ° C./50% RH for one month, the dicing die attach film in the dicing die attach film The adhesive sheet and the dicing film were separated, and the solution obtained by dissolving the adhesive layer in the adhesive sheet in THF was subjected to GPC to measure the content of the epoxy resin remaining in the adhesive layer. . The transfer amount (% by mass) of the epoxy resin from the adhesive sheet to the dicing film was determined by the formula: (E ₀ -E ₁ ) / E ₀ × 100 (where E ₀ is the epoxy in the initial adhesive layer) Resin content (parts by mass), E ₁ is the content (parts by mass) of the epoxy resin remaining in the adhesive layer after storage. GPC was performed using HLC8220 GPC (manufactured by Tosoh Corporation), and THF was used as an eluent.

(6) Adhesive strength of dicing die attach film after storage After the dicing die attach film prepared above is stored in a constant temperature and humidity chamber of 25 ° C./50% RH for one month, the dicing die attach film is stored in the dicing die attach film. The adhesive force between the adhesive sheet and the dicing film was measured based on JIS Z 0237.

(7) Pick-up property of the dicing die attach film after storage After the dicing die attach film prepared above is stored in a constant temperature and humidity room of 25 ° C./50% RH for one month, from this dicing die attach film The PET film was peeled off, a silicon wafer having a diameter of 8 inches and a thickness of 75 μm was mounted on the exposed adhesive layer, and diced under the following conditions to obtain a 10 mm × 10 mm silicon chip. 100 silicon chips diced in this way were picked up from the dicing film using a die bonder device (BESTEM-D02-TypeB) manufactured by NEC Machinery. In Table 1, “◯” represents that all silicon chips were stably picked up, and “x” represents that there was even one silicon chip that could not be picked up.

Dicing conditions:
Dicing machine: DAD-341 (manufactured by Disco)
Cutting method: Single cut Spindle speed: 40000 rpm
Dicing blade: NBC-ZH 104F 27HEEE (manufactured by Disco)
Feeding speed: 50mm / sec

  In the compositions (Examples 1 to 4) of the present invention, the (A) component was used as the (meth) acrylic resin, the (B) component was used as the epoxy resin, and the (C) component was used as the aromatic polyamine. On the other hand, the composition of Comparative Example 1 uses a component other than the component (C) as an aromatic polyamine, and the compositions of Comparative Examples 2 and 3 use a component other than the component (B) as an epoxy resin. In the product, components other than the component (A) were used as the (meth) acrylic resin. As shown in Table 1, the composition of the present invention is superior in embedding performance as compared to the compositions of Comparative Examples 1 to 4, and the cured adhesive layer obtained from the composition of the present invention is Comparative Examples 1 to 4. Compared to the cured adhesive layer obtained from the composition No. 4, the package reliability under moisture absorption is high. Further, the adhesive layer made of the composition of the present invention has a transfer amount of the epoxy resin to the dicing film as compared with the adhesive layer made of the composition of Comparative Example 3 using bisphenol A type epoxy resin as the epoxy resin. Less, the adhesive strength to the dicing film is small, and the pickup property is stable.

  The adhesive composition of the present invention is excellent in embedding performance, and the cured adhesive layer obtained from the adhesive composition has excellent adhesiveness, a low elastic modulus, and excellent heat resistance. Furthermore, the dicing die attach film of the present invention is excellent in characteristic stability and pickup stability even after being stored for a long time. Therefore, the adhesive composition of the present invention, and the adhesive sheet and dicing die attach film using the adhesive composition are useful for manufacturing a highly reliable semiconductor device.

1 Silicon chip 2 Resin substrate

Claims (4)

A dicing film having a base material and a pressure-sensitive adhesive layer provided thereon, and provided on the pressure-sensitive adhesive layer of the dicing film ,
(A) The weight average molecular weight is 50,000 to 1,500,000, the epoxy group and the following formula (1):

(1)

(Meth) acrylic resin having a structural unit represented by
(B) an epoxy resin having a dicyclopentadiene skeleton structure, and
(C) an aromatic polyamine having a diphenylsulfone skeleton structure
A dicing die attach film provided with an adhesive layer made of an adhesive composition comprising: The component (B) has the following structural formula (2):

(2)

(In the formula, n is a number of 0 or more.)
The dicing die attach film according to claim 1, which is an epoxy resin represented by: The diphenylsulfone skeleton structure in the component (C) has the following structural formula:

The dicing die attach film according to claim 1, which has a diphenylsulfone skeleton structure represented by: A dicing die attach film according to any one of claims 1 to 3 , wherein the dicing die attach film is separated from the adhesive layer when left at 25 ° C and 50% RH for one month from the production. The dicing die attach film, wherein the amount of the component in the adhesive layer transferred to the dicing film is suppressed to less than 30% by mass of the total component in the adhesive layer of the dicing die attach film before standing.

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