KR102455211B1 - Film adhesive for semiconductor, semiconductor device manufacturing method and semiconductor device - Google Patents

Abstract

The film adhesive for semiconductors of this invention is equipped with a 1st contact bonding layer and the 2nd contact bonding layer provided on this 1st contact bonding layer, The elastic modulus in 35 degreeC after hardening is 3.0-5.0 GPa.

Description

Film adhesive for semiconductor, semiconductor device manufacturing method and semiconductor device

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

Conventionally, in order to connect a semiconductor chip and a board|substrate, the wire bonding method using metal thin wires, such as a gold wire, is widely applied. On the other hand, in order to meet the demands for high functionalization, high integration, and high speed of semiconductor devices, a flip-chip connection method (FC connection method) in which conductive projections called bumps are formed on a semiconductor chip or substrate to directly connect the semiconductor chip and substrate (FC connection method) This is spreading.

For example, with respect to the connection between the semiconductor chip and the substrate, a COB (Chip On Board) type connection method actively used in BGA (Ball Grid Array), CSP (Chip Size Package), etc. also corresponds to the FC connection method. The FC connection method is also widely used in a COC (Chip On Chip) type connection method in which a connection portion (eg, bump and wiring) is formed on a semiconductor chip to connect the semiconductor chips (see, for example, Patent Document 1). .

Further, in a package that is strongly required for further miniaturization, thickness reduction, and high functionality, a chip stack type package, POP (Package On Package), TSV (Through), in which chips are stacked and multi-staged using the above-described connection method, -Silicon Via) is also beginning to be widely used. In this stacking/multilayering technique, since semiconductor chips and the like are arranged three-dimensionally, the package can be made small compared to a two-dimensional arrangement method. In addition, since it is effective for improving semiconductor performance, reducing noise, reducing mounting area, saving power, and the like, it is attracting attention as a next-generation semiconductor wiring technology.

Patent Document 1: Japanese Patent Laid-Open No. 2008-294382

However, in flip chip packages, high functionality and miniaturization are rapidly progressing. Along with high-functionality and miniaturization, the number of bumps increases, and narrower pitch and narrower gaps are progressing. When the number of bumps increases and the pitch and gap become narrow, voids such as trap voids that entrain the space around the bumps, and weld voids that occur in the rear part of the bumps due to the resin flow during compression occur after mounting. there is

Moreover, in a flip-chip package, it is calculated|required to shorten the crimping|compression-bonding time at the time of assembling a flip-chip package from a viewpoint of improving productivity. In order to shorten the crimping time, crimping at a high temperature is required, but in this high-temperature crimping, since the film adhesive for semiconductors becomes difficult to sufficiently harden during crimping, voids due to moisture and foaming components, and fine particles due to the entrainment A void may expand due to high temperature, generating many fatal voids. When using a flip-chip package for a long time, peeling may generate|occur|produce inside a package from these voids as a starting point. When the peeling inside the package increases, stress is applied to the connection portion and cracks occur, so the peeling inside the package leads to poor connection of the package.

Moreover, in a flip chip package, from a viewpoint of improving productivity, it is calculated|required that it mounts at the wafer level at the time of assembling a flip chip package. In this case, since a large number of packages are mounted on one bottom wafer, stress is applied to each package, and large warpage occurs in the bottom wafer. When the bottom wafer is warped, it becomes difficult to fix the bottom wafer to the suction table in the sealing step, which is the next step, and it becomes difficult to seal the package.

From the above reasons, in addition to the improvement of connection reliability, the performance which can achieve reduction of a void and reduction of a curvature is calculated|required by the film adhesive for semiconductors.

Therefore, the present invention suppresses the warpage of the bottom wafer even in mounting at the wafer level, and even when the crimping time is shortened, it is an object of the present invention to provide a film adhesive for semiconductors that can obtain excellent connection reliability without voids after mounting. do it with Moreover, an object of this invention is to provide the semiconductor device using such a film adhesive for semiconductors, and its manufacturing method.

MEANS TO SOLVE THE PROBLEM In order to reduce the curvature in the film adhesive of a single layer, the present inventors paid attention to the elastic modulus after hardening of the said film adhesive, and examined it. As a result, in a single-layer film adhesive, when the amount of the filler is increased in order to improve the elastic modulus, voids are easily generated, while when the amount of the curing agent is increased in order to reduce voids, the connection reliability decreases, and the connection reliability and voids are reduced. It became clear that it is difficult to reconcile the reduction of the sag and the reduction of the warpage. Then, as a result of the present inventors examining further, the present inventors made a film adhesive a film adhesive provided with a 1st adhesive layer and the 2nd adhesive layer provided on this 1st adhesive layer, and then set the elastic modulus after hardening to a specific range. By adjusting to , it was found that connection reliability, reduction of voids, and reduction of warpage were compatible, and the present invention was completed.

One aspect of this invention is equipped with a 1st contact bonding layer and the 2nd contact bonding layer provided on this 1st contact bonding layer, It relates to the film adhesive for semiconductors whose elasticity modulus in 35 degreeC after hardening is 3.0-5.0 GPa.

According to the said film adhesive for semiconductors, even when it suppresses the curvature of a bottom wafer also in mounting at a wafer level, and when crimping|compression-bonding time is shortened, the outstanding connection reliability can be acquired without a void after mounting. Moreover, according to the said film adhesive for semiconductors, since shortening of crimping|compression-bonding time is possible, productivity can be improved. Moreover, according to the said film adhesive for semiconductors, a flip-chip package can be made highly functional and highly integrated easily.

One aspect of the present invention is a film adhesive for semiconductors containing a filler, comprising a first adhesive layer and a second adhesive layer provided on the first adhesive layer, wherein the content of the filler is based on the total mass of the film adhesive for semiconductors. It relates to the film adhesive for semiconductors which is 30-60 mass % as this.

According to the said film adhesive for semiconductors, even when it suppresses the curvature of a bottom wafer also in mounting at a wafer level, and when crimping|compression-bonding time is shortened, the outstanding connection reliability can be acquired without a void after mounting. Moreover, according to the said film adhesive for semiconductors, since shortening of crimping|compression-bonding time is possible, productivity can be improved. Moreover, according to the said film adhesive for semiconductors, a flip-chip package can be made highly functional and highly integrated easily.

At least one of the first adhesive layer and the second adhesive layer may be a thermosetting adhesive layer, or both may be a thermosetting adhesive layer. In this case, shrinkage under the same environment as in the temperature cycle test can be reduced, and further excellent connection reliability can be easily obtained.

A thermosetting adhesive layer in which at least one of the first adhesive layer and the second adhesive layer contains a flux compound may be sufficient. In recent years, as a metal of a connection part, there exists a tendency for solder, copper, etc. to be used instead of gold etc. which are hard to corrode for the purpose of cost reduction. Also regarding the surface treatment of wirings and bumps, there is a tendency to use solder, copper, etc. instead of gold, which is difficult to corrode, for the purpose of reducing the cost. In particular, in flip-chip packages, since cost reduction is progressing, there is a tendency to use metals that are easily corroded and deteriorated in insulation, so that connection reliability (eg, insulation reliability) tends to decrease. In addition, as described above, in order to suppress the generation of impurities, there are cases where an OSP treatment or the like is performed to form an anti-oxidation film, but the anti-oxidation film causes deterioration of solder wettability during the connection process, deterioration of connectivity, etc. There are cases. On the other hand, when at least one of the first adhesive layer and the second adhesive layer contains the flux compound, the oxide film and impurities in the connection part can be removed, and there is a tendency that further excellent connection reliability can be obtained.

The flux compound may have a carboxyl group, may have two or more carboxyl groups, and may be a compound represented by the following formula (2). When such a flux compound is used, it is easy to obtain further excellent connection reliability.

[In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, and n represents 0 or an integer of 1 or more. A plurality of R ² may be the same or different from each other.]

The melting point of the flux compound may be 150° C. or less. In this case, since the flux is melted before the adhesive is cured during thermocompression bonding and the oxide film such as solder is reduced and removed, further excellent connection reliability is easily obtained.

One of the first adhesive layer and the second adhesive layer may be a thermosetting adhesive layer containing no flux compound. In this case, since the adhesive layer that does not contain a flux compound is hardly affected by the flux compound, the layer can exhibit properties of curing quickly and sufficiently after contacting the connecting parts with each other. Even in the case of carrying out, more excellent connection reliability (for example, insulation reliability) can be obtained.

When one of the first adhesive layer and the second adhesive layer does not contain a flux compound, the flux compound-free layer may contain a radical polymerizable compound and a thermal radical generator. In this case, since the curing rate is very excellent, even when crimping is performed at a high temperature and in a short time, voids are hardly generated, and more excellent connection reliability can be obtained.

A peroxide may be sufficient as the said thermal radical generating agent. In this case, since the further excellent handleability and storage stability can be acquired, the further excellent connection reliability is easy to be acquired.

A (meth)acrylic compound may be sufficient as the said radically polymerizable compound. In this case, it is easy to obtain the further excellent connection reliability.

The (meth)acrylic compound may have a fluorene-type skeleton. In this case, it is easy to obtain the further excellent connection reliability.

When one of the first adhesive layer and the second adhesive layer is a thermosetting adhesive layer that does not contain a flux compound, the thermosetting adhesive layer that does not contain a flux compound may contain an epoxy resin. In this case, it is easy to obtain the further excellent connection reliability and storage stability.

The thermosetting adhesive layer that does not contain the flux compound may further contain a latent curing agent. In this case, it is easy to obtain the further excellent connection reliability.

The latent curing agent may be an imidazole-based curing agent. In this case, since the flux activity which suppresses the formation of an oxide film in a connection part can be acquired, further excellent connection reliability is easy to be obtained.

One aspect of the present invention provides a method of manufacturing a semiconductor device in which each connection portion of a semiconductor chip and a wiring circuit board is electrically connected to each other, or a semiconductor device in which each connection portion of a plurality of semiconductor chips is electrically connected to each other, wherein at least a portion of the connection portion is provided. It is related with the manufacturing method of a semiconductor device provided with the process of sealing using the film adhesive for semiconductors mentioned above. According to this manufacturing method, a semiconductor device excellent in connection reliability (e.g. insulation reliability) without voids after mounting can be obtained even when the bending time of the bottom wafer is suppressed and the compression time is shortened even when mounting at the wafer level. . That is, according to the manufacturing method, a semiconductor device excellent in connection reliability (eg, insulation reliability) can be manufactured in a short time.

One aspect of the present invention is a semiconductor device in which each connection portion of a semiconductor chip and a wiring circuit board is electrically connected to each other, or a semiconductor device in which each connection portion of a plurality of semiconductor chips is electrically connected to each other, wherein at least a portion of the connection portion includes: It is related with the semiconductor device sealed with the hardened|cured material of the film adhesive for semiconductors. In this semiconductor device, warpage and voids are reduced, and excellent connection reliability (eg, insulation reliability) is exhibited.

ADVANTAGE OF THE INVENTION According to this invention, even when it suppresses the curvature of a bottom wafer even when mounting at a wafer level, even when crimping|compression-bonding time is shortened, the film adhesive for semiconductors which can obtain excellent connection reliability without a void after mounting can be provided. . Moreover, according to this invention, the semiconductor device using such a film adhesive for semiconductors, and its manufacturing method can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the semiconductor device of this invention.
Fig. 2 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention.
3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention.
4 is a process cross-sectional view schematically showing an embodiment of a method for manufacturing a semiconductor device of the present invention.

In this specification, "(meth)acrylate" means at least one of an acrylate and the methacrylate corresponding to it. The same applies to other similar expressions such as “(meth)acryloyl” and “(meth)acrylic acid”. In addition, the numerical range shown using "-" represents a range including the numerical value described before and after "-" as a minimum value and a maximum value, respectively. In addition, the upper and lower limits described individually can be arbitrarily combined.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be.

In addition, the same code|symbol is attached|subjected to the same or corresponding part in a figure, and overlapping description is abbreviate|omitted. In addition, the positional relationship, such as up-down, left-right, etc., shall be based on the positional relationship shown in drawing, unless it asks for the understanding in particular. In addition, the dimension ratio of a drawing is not limited to the ratio shown.

<Film-type adhesive for semiconductor>

The film adhesive for semiconductors of 1st Embodiment is equipped with the 1st contact bonding layer and the 2nd contact bonding layer provided on this 1st contact bonding layer, The elastic modulus in 35 degreeC after hardening is 3.0-5.0 GPa.

The film adhesive for semiconductors of 2nd embodiment is a film adhesive for semiconductors containing a filler, Comprising: A 1st contact bonding layer and the 2nd contact bonding layer provided on this 1st contact bonding layer are provided, and content of a filler is film adhesive for semiconductors. It is 30-60 mass % based on the total mass of.

The film adhesive for semiconductors of the first embodiment and the second embodiment is, for example, a non-conductive adhesive (film-type non-conductive adhesive for semiconductors), and the semiconductor chip and the semiconductor chip and the wiring circuit board are electrically connected to each other. In a device or a semiconductor device in which connection portions of a plurality of semiconductor chips are electrically connected to each other, they are used for sealing at least a part of the connection portions.

According to the film adhesive for semiconductors of the said 1st Embodiment and 2nd Embodiment, also in mounting at a wafer level, curvature of a bottom wafer is suppressed, and crimping|compression-bonding time (for example, crimping|compression-bonding to bond a semiconductor chip and a wiring circuit board together) Even when the crimping time in the step) is shortened (eg, when the crimping time is 5 seconds or less), excellent connection reliability can be obtained without voids after mounting.

Below, the film adhesive for semiconductors of 1st Embodiment is demonstrated in detail first.

(First embodiment)

In this embodiment, a 1st contact bonding layer and a 2nd contact bonding layer are mutually different layers, and are formed of the adhesive composition different from each other. At least one of the first adhesive layer and the second adhesive layer may be, for example, a thermosetting adhesive layer (adhesive layer comprising a thermosetting resin composition) formed of a thermosetting resin composition, or a photocurable adhesive layer formed of a photocurable resin composition (including a photocurable resin composition) adhesive layer) may be used. It is preferable that at least one of the first adhesive layer and the second adhesive layer is a thermosetting adhesive layer containing a thermosetting resin composition from the viewpoint of being able to reduce shrinkage under an environment such as a temperature cycle test, and to obtain further excellent connection reliability, It is more preferable that both are thermosetting adhesive layers.

The first adhesive layer and the second adhesive layer may be an adhesive layer containing a flux compound or may be an adhesive layer not containing a flux compound. That is, the resin composition constituting the first adhesive layer and the second adhesive layer may be a resin composition containing a flux compound (hereinafter referred to as “flux-containing composition”), or a resin composition containing no flux compound (hereinafter “flux-containing composition”). flux-free composition").

In general, metal bonding is used for the connection between the connection parts from the viewpoint of sufficiently ensuring connection reliability (eg, insulation reliability), and as the main metal used for the connection part (eg, bump and wiring), solder, tin, Gold, silver, copper, nickel, and the like. An electrically-conductive material containing these metals of several types is also used. On the other hand, as for the metal used for the connection part, the surface is oxidized to form an oxide film, and impurities such as oxide adhere to the surface, so that impurities may be generated on the connection surface of the connection part. When such impurities remain, the connection reliability (eg, insulation reliability) between the semiconductor chip and the substrate or between the two semiconductor chips decreases, and there is a possibility that the merit of employing the above-described FC connection method may be impaired. Therefore, as a method of suppressing the generation of these impurities, there is a method of coating a connection portion known as an OSP (Organic Solderbility Preservatives) treatment or the like with an antioxidant film. However, this antioxidant film may cause a fall in solder wettability during a connection process, a fall in connectivity, and the like. In contrast, in the present embodiment, when at least one of the first adhesive layer and the second adhesive layer is an adhesive layer containing a flux compound (for example, a thermosetting adhesive layer), superior connection reliability can be obtained without performing OSP treatment.

From the viewpoint of obtaining more excellent connection reliability, only one of the first adhesive layer and the second adhesive layer is an adhesive layer containing a flux compound (eg, thermosetting adhesive layer), and the other is an adhesive layer containing no flux compound (eg, thermosetting). adhesive layer).

Next, among the resin compositions constituting the first adhesive layer and the second adhesive layer, the flux-containing composition and the flux-free composition will be described.

(Flux containing composition)

The flux-containing composition is, for example, a thermosetting resin composition, and contains a thermosetting component and a flux compound. As a thermosetting component, a thermosetting resin, a hardening|curing agent, etc. are mentioned. As a thermosetting resin, an epoxy resin, a phenol resin (except when contained as a hardening|curing agent), polyimide resin, etc. are mentioned, for example. Among these, it is preferable that a thermosetting resin is an epoxy resin. Moreover, the film adhesive for semiconductors of this embodiment may contain the polymer component and filler whose weight average molecular weight is 10000 or more as needed.

Hereinafter, the flux-containing composition includes an epoxy resin (hereinafter referred to as "component (a)" in some cases), a curing agent (hereinafter referred to as "component (b)" in some cases), and a flux compound (hereinafter referred to as "component (b)" in some cases). , sometimes referred to as "component (c)") and, if necessary, a polymer component having a weight average molecular weight of 10000 or more (hereinafter referred to as "component (d)" in some cases) and fillers (hereinafter, in the case One embodiment containing "(e) component" will be described.

[(a) component: epoxy resin]

As an epoxy resin, if it has two or more epoxy groups in a molecule|numerator, it can use without restriction|limiting in particular. (a) As a component, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a naphthalene type epoxy resin, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a phenol aralkyl type epoxy resin, a biphenyl type epoxy resin, A triphenylmethane type epoxy resin, a dicyclopentadiene type epoxy resin, and various polyfunctional epoxy resins can be used. These can be used individually or as a mixture of 2 or more types.

From the viewpoint of suppressing that the component (a) is decomposed at the time of connection at a high temperature to suppress generation of volatile components, when the temperature at the time of connection is 250°C, the thermogravimetric decrease ratio at 250°C is 5% or less epoxy It is preferable to use resin, and when the temperature at the time of connection is 300 degreeC, it is preferable to use the epoxy resin whose thermogravimetric reduction amount ratio in 300 degreeC is 5 % or less.

The content of component (a) is, for example, 5 mass% or more, preferably 10 mass% or more, and more preferably 15 mass% or more, based on the total mass of the flux-containing composition from the viewpoint of high heat resistance. The content of the component (a) is, for example, 75 mass% or less, 50 mass% or less, 45 mass% or less, or 35 mass% or less, based on the total mass of the flux-containing composition from the viewpoint of film processability. From these viewpoints, content of (a) component is 5-75 mass %, 10-50 mass %, 15-45 mass %, or 15-35 mass %, for example.

[(b) component: curing agent]

Examples of the component (b) include a phenol resin curing agent, an acid anhydride curing agent, an amine curing agent, an imidazole curing agent, and a phosphine curing agent. When the component (b) contains a phenolic hydroxyl group, an acid anhydride, an amine, or an imidazole, flux activity for suppressing the formation of an oxide film on the connection portion is exhibited, and connection reliability and insulation reliability can be improved. An imidazole-type hardening|curing agent is used more preferably from a viewpoint of being easy to acquire such an effect. Hereinafter, each hardening|curing agent is demonstrated.

(i) phenolic resin curing agent

The phenolic resin curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule. For example, phenol novolak resin, cresol novolak resin, phenol aralkyl resin, cresolnaphthol formaldehyde polycondensate, triphenylmethane type polyfunctional Phenolic resins and various polyfunctional phenolic resins can be used. These can be used individually or as a mixture of 2 or more types.

The equivalent ratio of the phenolic resin curing agent to the component (a) (the number of moles of phenolic hydroxyl groups that the phenolic resin curing agent has / the number of moles of epoxy groups that the component (a) has) is 0.3 to 1.5 is preferable, 0.4-1.0 are more preferable, and 0.5-1.0 are still more preferable. When the equivalence ratio is 0.3 or more, curability tends to improve and adhesive strength tends to improve, and when it is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively, water absorption is suppressed low, and insulation reliability tends to be improved.

(ii) acid anhydride curing agent

As the acid anhydride curing agent, for example, methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride and ethylene glycol bisanhydrotrimellitate can be used. These can be used individually or as a mixture of 2 or more types.

The equivalent ratio of the acid anhydride curing agent to the component (a) (the number of moles of the acid anhydride groups of the acid anhydride curing agent / the number of moles of the epoxy groups of the component (a)) is, from the viewpoint of good curability, adhesiveness and storage stability, 0.3-1.5 are preferable, 0.4-1.0 are more preferable, 0.5-1.0 are still more preferable. When the equivalence ratio is 0.3 or more, curability tends to improve and adhesive strength tends to improve, and when it is 1.5 or less, unreacted acid anhydride does not remain excessively, water absorption is suppressed low, and insulation reliability tends to be improved.

(iii) amine-based curing agent

As the amine curing agent, for example, dicyandiamide can be used.

The equivalent ratio of the amine-based curing agent to the component (a) (the number of moles of active hydrogen groups in the amine-based curing agent / the number of moles of epoxy groups in the component (a)) is 0.3 to 1.5 from the viewpoint of good curability, adhesion and storage stability. is preferable, 0.4 to 1.0 are more preferable, and 0.5 to 1.0 are still more preferable. When the equivalence ratio is 0.3 or more, curability is improved and adhesive strength tends to be improved, and when it is 1.5 or less, unreacted amine does not remain excessively and insulation reliability tends to be improved.

(iv) imidazole-based curing agent

Examples of the imidazole-based curing agent include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 1-cya. Noethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenyl Midazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'- Undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl- s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazineisocyanuric acid adduct, 2-phenylimidazoleisocyanuric acid adducts, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles are mentioned. . Among these, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-unde from a viewpoint of the outstanding sclerosis|hardenability, storage stability, and connection reliability. Silimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl- s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl-(1')]-ethyl-s-triazineisocyanuric acid adduct, 2-phenylimidazolisocyanuric acid adduct, 2-phenyl-4,5-dihydr Preference is given to hydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These can be used individually or in combination of 2 or more types. Moreover, it is good also as a latent hardening|curing agent which microencapsulated these.

As for content of an imidazole type hardening|curing agent, 0.1 mass part or more is preferable with respect to 100 mass parts of (a) component. It exists in the tendency for sclerosis|hardenability to improve that content of an imidazole type hardening|curing agent is 0.1 mass part or more. Moreover, 20 mass parts or less are preferable and, as for content of an imidazole type hardening|curing agent, 10 mass parts is more preferable. When the content of the imidazole-based curing agent is 20 parts by mass or less, the fluidity of the flux-containing composition during crimping can be ensured, and the flux-containing composition between the connecting portions can be sufficiently eliminated. As a result, since curing of the flux-containing composition in a state interposed between the solder and the connecting portion is suppressed, there is a tendency for poor connection to occur. From these viewpoints, 0.1-20 mass parts is preferable with respect to 100 mass parts of (a) component, and, as for content of an imidazole type hardening|curing agent, 0.1-10 mass parts is more preferable.

(v) phosphine-based curing agent

Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphoniumtetraphenylborate, tetraphenylphosphoniumtetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

0.1-10 mass parts is preferable with respect to 100 mass parts of (a) component, and, as for content of a phosphine-type hardening|curing agent, 0.1-5 mass parts is more preferable. If the content of the phosphine-based curing agent is 0.1 parts by mass or more, curability tends to be improved, and if it is 10 parts by mass or less, the flux-containing composition does not harden before metal bonding is formed, and there is a tendency that poor connection tends to occur.

Each of the phenol resin curing agent, the acid anhydride curing agent and the amine curing agent may be used alone or as a mixture of two or more thereof. The imidazole-based curing agent and the phosphine-based curing agent may be used alone, or may be used together with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

When the flux-containing composition contains a phenol resin curing agent, an acid anhydride curing agent, or an amine curing agent as component (b), it exhibits flux activity for removing an oxide film, thereby further improving connection reliability.

[(c) component: flux compound]

Component (c) is a compound having flux activity, and functions as a flux compound in a flux-containing composition. As the component (c), a known component can be used without particular limitation, as long as it facilitates metal bonding by reducing and removing an oxide film on the surface of solder or the like. (c) As a component, 1 type of flux compound may be used individually, and 2 or more types of flux compound may be used together. However, the hardening|curing agent which is (b) component is not contained in (c) component.

The flux compound preferably has a carboxyl group, and more preferably has two or more carboxyl groups, from the viewpoint that sufficient flux activity can be obtained and superior connection reliability can be obtained. Among these, the compound which has two carboxyl groups is preferable. Compared with the compound (monocarboxylic acid) which has one carboxyl group, the compound which has two carboxyl groups is hard to volatilize also by the high temperature at the time of connection, and can suppress generation|occurrence|production of a void further. Moreover, when the compound which has two carboxyl groups is used, compared with the case where the compound which has three or more carboxyl groups is used, the increase in the viscosity of the film adhesive for semiconductors at the time of storage, connection work, etc. can be suppressed further, , the connection reliability of the semiconductor device can be further improved.

As the flux compound having a carboxyl group, a compound having a group represented by the following formula (1) is preferably used.

In formula (1), R ¹ represents a hydrogen atom or an electron-donating group.

From a viewpoint of being excellent in reflow resistance and a viewpoint of being further excellent in connection reliability, it is preferable that R< ¹ > is an electron donating property. In the present embodiment, the flux-containing composition contains an epoxy resin and a curing agent, and then, among the compounds having a group represented by the formula (1), further contains a compound in which R ¹ is an electron-donating group, whereby flip metal bonding Even when it applies as a film adhesive for semiconductors in a chip connection system, manufacture of the semiconductor device more excellent in reflow resistance and connection reliability is attained.

For the improvement of reflow property, it is necessary to suppress the adhesive force fall after moisture absorption in high temperature. Although carboxylic acid is conventionally used as a flux compound, the present inventors consider that the fall of adhesive force arises in the conventional flux compound for the following reasons.

In general, the curing reaction proceeds by reacting the epoxy resin with the curing agent. At this time, the carboxylic acid, which is a flux compound, is taken into the curing reaction. That is, an ester bond may be formed when the epoxy group of an epoxy resin reacts with the carboxyl group of a flux compound. This ester bond is likely to cause hydrolysis due to moisture absorption or the like, and it is considered that decomposition of the ester bond is one cause of the decrease in the adhesive force after moisture absorption.

On the other hand, among the compounds having a group represented by formula (1), when a compound having a group in which R ¹ is an electron-donating group, that is, a compound having a carboxyl group having an electron-donating group in the vicinity, is contained, the flux activity is reduced by the carboxyl group. While sufficiently obtained, even when the above-described ester bond is formed, the electron density of the ester bond portion is increased by the electron-donating group, and decomposition of the ester bond is suppressed. Moreover, since a substituent (electron-donating group) exists in the vicinity of a carboxyl group, reaction of a carboxyl group and an epoxy resin is suppressed by steric hindrance, and it is thought that it becomes difficult to produce|generate an ester bond.

For these reasons, among the compounds having a group represented by the formula (1), when a flux-containing composition further containing a compound in which R ¹ is an electron-donating group is used, composition change due to moisture absorption or the like hardly occurs, and excellent adhesion is maintained. do. In addition, it can be said that the above-mentioned action is difficult to inhibit the curing reaction of the epoxy resin and the curing agent by the flux compound. can

When the electron-donating group of the electron-donating group becomes strong, the effect of suppressing the decomposition of the above-described ester bond tends to be easily obtained. Moreover, when the steric hindrance of an electron-donating group is large, it will become easy to acquire the effect of suppressing reaction of the above-mentioned carboxyl group and an epoxy resin. The electron-donating group preferably has a good balance between electron donating and steric hindrance.

Examples of the electron-donating group include an alkyl group, a hydroxyl group, an amino group, an alkoxy group and an alkylamino group. As the electron-donating group, a group that does not readily react with other components (eg, the epoxy resin of component (a)) is preferable, and specifically, an alkyl group, a hydroxyl group or an alkoxy group is preferable, and an alkyl group is more preferable.

As an alkyl group, a C1-C10 alkyl group is preferable, and a C1-C5 alkyl group is more preferable. As the number of carbon atoms in the alkyl group increases, electron donating and steric hindrance tend to increase. Since the alkyl group having carbon number within the above range is excellent in the balance between electron donating and steric hindrance, the effect of the present invention is further remarkably exhibited according to the above alkyl group.

Moreover, linear or branched form may be sufficient as an alkyl group, and it is preferable that it is linear. When the alkyl group is linear, it is preferable that the carbon number of the alkyl group is not more than the carbon number of the main chain of the flux compound from the viewpoint of the balance of electron donating and steric hindrance. For example, when the flux compound is a compound represented by the following formula (2) and the electron-donating group is a linear alkyl group, the number of carbon atoms in the alkyl group is preferably not more than (n+1) carbon atoms in the main chain of the flux compound.

As an alkoxy group, a C1-C10 alkoxy group is preferable and a C1-C5 alkoxy group is more preferable. There is a tendency for electron donating and steric hindrance to increase as the number of carbon atoms in the alkoxy group increases. Since the alkoxy group having the carbon number within the above range is excellent in the balance between electron donating and steric hindrance, the effect of the present invention is further remarkably exhibited according to the above-mentioned alkoxy group.

Moreover, linear or branched form may be sufficient as the alkyl group part of an alkoxy group, and it is preferable that it is linear. When the alkoxy group is linear, it is preferable that the carbon number of the alkoxy group is not more than the carbon number of the main chain of the flux compound from the viewpoint of the balance of electron donating and steric hindrance. For example, when the flux compound is a compound represented by the following formula (2) and the electron-donating group is a straight-chain alkoxy group, the number of carbon atoms in the alkoxy group is preferably less than or equal to the number of carbon atoms in the main chain of the flux compound (n+1).

Examples of the alkylamino group include a monoalkylamino group and a dialkylamino group. As a monoalkylamino group, a C1-C10 monoalkylamino group is preferable, and a C1-C5 monoalkylamino group is more preferable. The alkyl group part of the monoalkylamino group may be linear or branched, and it is preferable that it is linear.

As a dialkylamino group, a C2-C20 dialkylamino group is preferable, and a C2-C10 dialkylamino group is more preferable. The alkyl group portion of the dialkylamino group may be linear or branched, and is preferably linear.

As the flux compound having two carboxyl groups, a compound represented by the following formula (2) can be suitably used. According to the compound represented by following formula (2), the reflow resistance and connection reliability of a semiconductor device can be improved further.

In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, and n represents 0 or an integer of 1 or more. A plurality of R ² s may be the same or different from each other.

R ¹ is synonymous with R ¹ in Formula (1). In addition, the electron-donating group represented by ^R2 is the same as the example of the above-mentioned electron-donating group demonstrated as R< ¹ >. For the same reason as explained in formula (1), it is preferable that R ¹ in formula (2) is an electron-donating group.

It is preferable that n in Formula (2) is 1 or more. When n is 1 or more, compared with the case where n is 0, the flux compound is less likely to volatilize even at a high temperature during connection, and generation of voids can be further suppressed. Moreover, it is preferable that n in Formula (2) is 15 or less, It is more preferable that it is 11 or less, 6 or less or 4 or less may be sufficient. When n is 15 or less, further excellent connection reliability can be obtained.

Moreover, as a flux compound, the compound represented by following formula (3) is more suitable. According to the compound represented by following formula (3), the reflow resistance and connection reliability of a semiconductor device can be improved further.

In formula (3), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, and m represents 0 or an integer of 1 or more.

It is preferable that m in Formula (3) is 10 or less, It is more preferable that it is 5 or less, It is still more preferable that it is 3 or less. When m is 10 or less, further excellent connection reliability can be obtained.

In Formula (3), R< ¹ > and R< ² > may be a hydrogen atom or an electron-donating group may be sufficient as it. It is preferable that at least one of R< ¹ > and R< ² > is an electron-donating group from a viewpoint of being able to acquire the further outstanding connection reliability. When R ¹ is an electron-donating group and R ² is a hydrogen atom, the melting point tends to be low and the connection reliability of the semiconductor device can be further improved in some cases. In addition, when R ¹ and R ² are different electron-donating groups, compared to the case where R ¹ and R ² are the same electron-donating groups, the melting point tends to be lowered, which can further improve the connection reliability of the semiconductor device. There are cases.

Moreover, when R< ¹ > and R< ² > are the same electron-donating group in Formula (3), it becomes a symmetric structure and there exists a tendency for melting|fusing point to become high. Even in this case, the effect of this invention is fully acquired. In particular, when the melting point is sufficiently low at 150° C. or less, even if R ¹ and R ² are the same group, the same level of connection reliability as in the case where R ¹ and R ² are different groups can be obtained.

Examples of the flux compound include dicarboxylic acids selected from succinic acid, glutaric acid, adipic acid, pimelinic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid, and these dicarboxylic acids. A compound in which an electron-donating group is substituted at the 2-position of the acid may be used.

150 degrees C or less is preferable, as for melting|fusing point of a flux compound, 140 degrees C or less is more preferable, and 130 degrees C or less is still more preferable. Such a flux compound tends to sufficiently exhibit flux activity before the curing reaction between the epoxy resin and the curing agent occurs. Therefore, according to the film adhesive for semiconductors using such a flux compound, the semiconductor device further excellent in connection reliability can be implement|achieved. Moreover, 25 degreeC or more is preferable and, as for melting|fusing point of a flux compound, 50 degreeC or more is more preferable. In addition, it is preferable that the flux compound is solid at room temperature (25°C).

The melting point of the flux compound can be measured using a general melting point measuring device. The sample for which the melting point is measured is pulverized into a fine powder, and it is required to reduce the temperature variation in the sample by using a trace amount. A capillary tube closed at one end is often used as a container for a sample, but depending on the measuring device, it is used as a container by sandwiching two microscope cover glasses. In addition, if the temperature is raised rapidly, a temperature gradient is generated between the sample and the thermometer, which causes measurement errors. Therefore, the heating at the time of measuring the melting point is preferably measured at a rate of increase of 1° C. or less per minute.

As described above, since the material for measuring the melting point is prepared as a fine powder, the sample before melting is opaque due to diffuse reflection from the surface. It is common that the temperature at which the appearance of the sample begins to become transparent is the lower limit of the melting point, and the temperature at which the sample has been melted is the upper limit. Various types of measuring devices exist, but the most classic device is a device that heats the sample with a hot bath by attaching a capillary filled with a sample to a double-tube thermometer. For the purpose of bonding the capillary to the double tube thermometer, a liquid with high viscosity is used as the liquid of the warm bath, and concentrated sulfuric acid or silicone oil is often used. Moreover, as a melting|fusing point measuring apparatus, while heating using a metal heat block, while measuring the light transmittance, what determines melting|fusing point automatically while preparing heating can also be used.

In addition, in this specification, melting|fusing point 150 degreeC or less means that the upper limit of melting|fusing point is 150 degrees C or less, and melting|fusing point 25 degreeC or more means that the lower limit of melting|fusing point is 25 degreeC or more.

(c) The content of the component is preferably 0.5 to 10 mass%, more preferably 0.5 to 5 mass%, based on the total mass of the flux-containing composition.

[Component (d): polymer component having a weight average molecular weight of 10000 or more]

The flux-containing composition may contain, if necessary, a polymer component (component (d)) having a weight average molecular weight of 10000 or more. The flux-containing composition containing the component (d) is further excellent in heat resistance and film formability.

(d) As the component, for example, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, and acrylic rubber are mentioned. Among these, phenoxy resins, polyimide resins, acrylic rubbers, cyanate ester resins and polycarbodiimide resins are preferable from the viewpoint of excellent heat resistance and film formation properties, and phenoxy resins, polyimide resins and acrylic rubbers are more preferable. desirable. These (d) components may be used individually or as a mixture or copolymer of 2 or more types. However, the compound corresponding to the component (a) and the compound corresponding to the component (e) are not included in (d) component.

(d) The weight average molecular weight of the component is, for example, 10000 or more, preferably 20000 or more, and more preferably 30000 or more. According to such component (d), the heat resistance and film formability of the flux-containing composition can be further improved.

Moreover, it is preferable that it is 1000000 or less, and, as for the weight average molecular weight of (d) component, it is more preferable that it is 500000 or less. According to such component (d), the heat resistance of the flux-containing composition can be further improved.

In addition, in this specification, a weight average molecular weight means the weight average molecular weight when it measures in polystyrene conversion using high performance liquid chromatography (The Shimadzu Corporation make, brand name: C-R4A). For the measurement, for example, the following conditions can be used.

Detector: LV4000 UV Detector (manufactured by Hitachi, Ltd., trade name)

Pump: L6000 Pump (manufactured by Hitachi, Ltd., trade name)

Column: Gelpack GL-S300MDT-5 (2 copies in total) (manufactured by Hitachi, Ltd., trade name)

Eluent: THF/DMF=1/1 (volume ratio)+LiBr(0.03 mol/L)+H ₃ PO ₄ (0.06 mol/L)

Flow: 1 mL/min

When the flux-containing composition contains the component (d), the ratio C _a /C _d (mass ratio) of the content C _a of the component (a) to the content C _d of the component (d) is preferably 0.01 to 5 , It is more preferable that it is 0.05-3, and it is still more preferable that it is 0.1-2. When the ratio (C _a /C _d ) is 0.01 or more, better curability and adhesive force can be obtained, and when the ratio (C _a /C _d ) is 5 or less, better film formability can be obtained.

[(e) component: filler]

The flux-containing composition may contain a filler (component (e)) as needed. The component (e) can control the viscosity of the flux-containing composition, physical properties of the cured product of the flux-containing composition, and the like. Specifically, according to the component (e), the elastic modulus (for example, the elastic modulus in 35 degreeC) after hardening of the film adhesive for semiconductors can be adjusted, suppression of the void generation|occurrence|production at the time of connection, and the hardened|cured material moisture absorption rate of a flux containing composition reduction, etc. can be achieved.

(e) As a component, an inorganic filler (inorganic particle), an organic filler (organic particle), etc. are mentioned. Examples of the inorganic filler include insulating inorganic fillers such as glass, silica, alumina, titanium oxide, mica, and boron nitride, and among them, at least one selected from the group consisting of silica, alumina, titanium oxide and boron nitride is preferable, At least one selected from the group consisting of silica, alumina and boron nitride is more preferable. A whisker may be sufficient as an insulating inorganic filler. Examples of the whisker include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, and boron nitride. As an organic filler, a resin filler (resin particle) is mentioned, for example. Polyurethane, polyimide, etc. are mentioned as a resin filler. Since a resin filler can provide flexibility at high temperature, such as 260 degreeC, compared with an inorganic filler, while being suitable for a reflow resistance improvement, since softness provision is possible, it is effective also in film formability improvement. On the other hand, from the viewpoint that it is easy to adjust the elastic modulus to a desired range, and it is easy to adjust the viscosity of the film while suppressing warpage, the occurrence of voids can be more fully reduced, and further, from the viewpoint that excellent connection reliability can be obtained, inorganic fillers is preferably used.

From the viewpoint that the content of the inorganic filler is easy to adjust the elastic modulus to a desired range, the generation of voids can be more sufficiently reduced while suppressing the warpage, and further, from the viewpoint that excellent connection reliability can be obtained, the component (e) 50 mass % or more, 70 mass % or more, or 90 mass % or more may be sufficient based on the total mass. (e) The component may consist substantially of an inorganic filler. That is, the component (e) does not need to contain an organic filler substantially. "It does not contain substantially" means that content of the organic filler in (e) component is less than 0.5 mass % on the basis of the total mass of (e) component.

From the viewpoint of further excellent insulation reliability, the component (e) is preferably a filler having insulation (insulating filler). It is preferable that the flux-containing composition does not contain conductive metal fillers (metal particles) such as silver filler and solder filler and conductive fillers such as carbon black (eg inorganic filler).

From the viewpoint that the content of the insulating filler is easy to adjust the elastic modulus to a desired range, the occurrence of voids while suppressing warpage can be more sufficiently reduced, and further superior connection reliability can be obtained from the viewpoint of the component (e) 50 mass % or more, 70 mass % or more, or 90 mass % or more may be sufficient based on the total mass. (e) The component may contain only an insulating filler substantially. That is, the component (e) does not need to contain an electroconductive filler substantially. "It does not contain substantially" means that content of the electroconductive filler in (e) component is less than 0.5 mass % based on the total mass of (e) component.

(e) The physical properties of the component may be appropriately adjusted by surface treatment. (e) It is preferable that a component is the filler which surface-treated from a viewpoint that dispersibility or adhesive force improves. As a surface treatment agent, the compound of a glycidyl type (epoxy type), an amine type, a phenyl type, a phenylamino type, a (meth)acrylic type, a vinyl type, etc. are mentioned.

As the surface treatment, silane treatment with a silane compound such as an epoxysilane type, an aminosilane type or an acrylsilane type is preferable from the viewpoint of the easiness of the surface treatment. As the surface treating agent, at least one selected from the group consisting of a glycidyl compound, a phenylamino compound and a (meth)acrylic compound is preferable from the viewpoint of excellent dispersibility, fluidity and adhesion. As a surface treating agent, at least 1 sort(s) chosen from the group which consists of a phenyl-type compound and a (meth)acrylic-type compound from a viewpoint of being excellent in storage stability is preferable.

(e) The average particle diameter of the component is preferably 1.5 µm or less from the viewpoint of preventing meshing at the time of flip-chip connection, and more preferably 1.0 µm or less from the viewpoint of excellent visibility (transparency).

The content of the component (e) is preferably 5 mass% or more, more preferably 10 mass% or more, still more preferably 20 mass% or more, based on the total mass of the flux-containing composition. (e) When content of a component is 5 mass % or more, the amount of expansion with respect to a heat|fever becomes small. In addition, since the expansion of micro voids can be suppressed, connection reliability (particularly, connection reliability when used in an environment such as a temperature cycle test) is more excellent. The content of the component (e) is preferably 80 mass% or less, more preferably 70 mass% or less, still more preferably 60 mass% or less, based on the total mass of the flux-containing composition. (e) When content of component is 80 mass % or less, since resin fully excludes at the time of thermocompression bonding, it is more excellent in connection reliability. From these viewpoints, the content of component (e) is preferably 5-80 mass%, more preferably 10-70 mass%, furthermore 20-60 mass%, based on the total mass of the flux-containing composition. desirable.

[Other Ingredients]

Additives, such as antioxidant, a silane coupling agent, a titanium coupling agent, a leveling agent, and an ion trap agent, may be mix|blended with a flux containing composition. These can be used individually by 1 type or in combination of 2 or more type. About these compounding quantities, what is necessary is just to adjust suitably so that the effect of each additive may be expressed.

(Flux-free composition)

The flux-free composition is, for example, a thermosetting resin composition. The flux-free composition is substantially free of flux compounds. "Substantially free" means that the content of the flux compound in the flux-free composition is less than 0.5 mass% based on the total mass of the flux-free composition.

The flux-free composition preferably has a curing reaction rate of 80% or more when held at 200° C. for 5 seconds from the viewpoint that the effects of the present invention can be remarkably obtained. Examples of such flux-free compositions include radical curing adhesives. In the present embodiment, when one of the first adhesive layer and the second adhesive layer is an adhesive layer formed by the flux-containing composition and the other is an adhesive layer formed by the flux-free composition, the effects of the present invention are particularly easily obtained. . Although the reason why the effect of this invention can be acquired remarkably by such an adhesive agent is not clear, the present inventors guess as follows.

That is, in the conventional film adhesive containing a flux compound, since a flux component deactivates radicals, a radical curing system could not be applied, but the cationic curing system using an epoxy etc. was applied in many cases. In this curing system (reaction system), since curing proceeds by nucleophilic addition reaction, the curing rate is slow, and voids may be generated after crimping. In the conventional film adhesive, it is guessed that the problem (for example, peeling of the semiconductor material in the reflow temperature around 260 degreeC, connection defect of a connection part, etc.) had generate|occur|produced by the void at the time of this mounting. On the other hand, since the flux-free composition described above does not contain a flux compound substantially, the curing system can be a radical curing system, and a sufficient curing rate can be obtained. Therefore, by using the flux-free composition as described above for the first or second adhesive layer, it is conjectured that voids are less likely to be generated even when compression is performed at a high temperature and in a short time, and the effect of the present invention is conspicuous. In addition, in this embodiment, since a sufficient curing rate can be obtained, for example, even when solder is used for a connection part, a film adhesive can be hardened in the temperature range lower than the solder melting temperature. Accordingly, it is possible to sufficiently suppress the occurrence of solder scattering and flow, resulting in poor connection.

Hereinafter, the flux-free composition includes a radical polymerizable compound (hereinafter, sometimes referred to as "component (A)"), and a thermal radical generator (hereinafter referred to as "component (B)" in some cases.) And, as needed, with respect to an embodiment containing a polymer component (hereinafter, sometimes referred to as “(C) component”) and a filler (hereinafter referred to as “(D) component” in some cases.) Explain.

[Component (A): radically polymerizable compound]

Component (A) is a compound capable of radical polymerization reaction by generating radicals by heat, light, radiation, electrochemical action, or the like. (A) As a component, a (meth)acrylic compound, a vinyl compound, etc. are mentioned. (A) As a component, a (meth)acrylic compound is preferable from a viewpoint of being excellent in durability, electrical insulation, and heat resistance. The (meth)acrylic compound is not particularly limited as long as it is a compound having one or more (meth)acryl group ((meth)acryloyl group) in the molecule, for example, bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type (meth)acrylic compound containing skeleton of cresol novolak type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, fluorene type, adamantane type or isocyanuric acid type; Various polyfunctional (meth)acryl compounds (except the (meth)acrylic compound containing the said skeleton) etc. can be used. Examples of the polyfunctional (meth)acrylic compound include pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and trimethylolpropane di(meth)acrylate. (A) A component can be used individually by 1 type or in combination of 2 or more types.

From the viewpoint of excellent heat resistance, the component (A) preferably has a bisphenol A skeleton, a bisphenol F skeleton, a naphthalene skeleton, a fluorene skeleton, an adamantane skeleton or an isocyanuric acid skeleton, fluorene It is more preferable to have a type|mold skeleton. As for (A) component, it is more preferable that it is (meth)acrylate which has any frame|skeleton mentioned above.

It is preferable that (A) component is solid at room temperature (25 degreeC). Compared to the liquid type, voids are less likely to occur in the solid type, and the viscosity (tack) of the flux-free composition before curing (B stage) is small and thus excellent in handling. As component (A) which is solid at room temperature (25 degreeC), the (meth)acrylate etc. which have a bisphenol A-type skeleton, a fluorene-type skeleton, an adamantane-type skeleton, or an isocyanuric-acid-type skeleton are mentioned.

As for the number of the functional groups of the (meth)acryl group in (A) component, 3 or less are preferable. When the number of functional groups is large, the network of curing may proceed rapidly, and unreacted groups may remain. On the other hand, when the number of functional groups is 3 or less, the number of functional groups does not increase too much and hardening in a short time is easy to fully advance, so it is easy to suppress that hardening reaction rate falls.

(A) It is preferable that it is smaller than 2000, and, as for the molecular weight of a component, it is more preferable that it is 1000 or less. (A) Reaction advances easily, so that the molecular weight of a component is small, and hardening reaction rate becomes high.

The content of component (A) is preferably 10% by mass or more based on the total mass of the flux-free composition from the viewpoint of suppressing the decrease in the amount of curing components and making it easy to sufficiently control the flow of the resin after curing, 15 mass % or more is more preferable. The content of component (A) is preferably 50% by mass or less, based on the total mass of the flux-free composition, from the viewpoint that the cured product is suppressed from becoming too hard and the package warpage tends to be easily suppressed. and 45 mass % or less is more preferable, and 40 mass % or less is still more preferable. From these viewpoints, the content of component (A) is preferably 10 to 50 mass%, more preferably 10 to 45 mass%, still more preferably 15 to 40 mass%, based on the total mass of the flux-free composition. do.

From a viewpoint that content of (A) component is suppressed that sclerosis|hardenability falls and it is easy to suppress that adhesive force falls, 0.01 mass part or more is preferable with respect to 1 mass part of (C)component, and 0.05 mass part or more This is more preferable, and 0.1 mass part or more is still more preferable. (A) From a viewpoint that it is easy to suppress that film formation property falls, 10 mass parts or less are preferable with respect to 1 mass part of (C)component, and, as for content of (A) component, 5 mass parts or less are more preferable. From these viewpoints, 0.01-10 mass parts is preferable with respect to 1 mass part of (C)component, as for content of (A) component, 0.05-5 mass parts is more preferable, 0.1-5 mass parts is still more preferable.

[(B) component: thermal radical generator]

Although there will be no restriction|limiting in particular as a component as long as it functions as a hardening|curing agent of (A) component, From a viewpoint of being excellent in handleability, a thermal radical generator is preferable.

As a thermal radical generating agent, an azo compound, a peroxide (organic peroxide etc.), etc. are mentioned. As a thermal radical generating agent, a peroxide is preferable and an organic peroxide is more preferable. In this case, a radical reaction does not progress in the process of drying the solvent at the time of setting it as a film form, and it is excellent in handling property and storage stability. Therefore, when using a peroxide as a thermal radical generating agent, the further outstanding connection reliability is easy to be acquired. Examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, and peroxyester. As an organic peroxide, at least 1 sort(s) selected from the group which consists of a hydroperoxide, a dialkyl peroxide, and peroxyester from a viewpoint of being excellent in storage stability is preferable. Moreover, as an organic peroxide, at least 1 sort(s) selected from the group which consists of a hydroperoxide and a dialkyl peroxide from a viewpoint of being excellent in heat resistance is preferable. Examples of the dialkyl peroxide include dicumyl peroxide and di-tert-butyl peroxide.

From a viewpoint that hardening fully advances easily, 0.5 mass part or more is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component, 1 mass part or more is more preferable. (B) 10 mass parts or less are preferable with respect to 100 mass parts of (A) component, and, as for content of component, 5 mass parts or less are more preferable. (B) When the upper limit of content of a component is the said range, hardening advances rapidly and it is suppressed that reaction points increase, and it is suppressed that a molecular chain becomes short and unreacted group remains. Therefore, it is easy to suppress the fall of reliability that the upper limit of content of (B) component is the said range. From these viewpoints, 0.5-10 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component, 1-5 mass parts is more preferable.

[(C) component: polymer component]

The flux-free composition may further contain a polymer component. (C) component is epoxy resin, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, (meth)acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resins, polyvinyl acetal resins, urethane resins, acrylic rubbers, and the like, and among them, epoxy resins, phenoxy resins, polyimide resins, and (meth)acrylic resins from the viewpoint of excellent heat resistance and film formability. , preferably at least one selected from the group consisting of acrylic rubber, cyanate ester resin and polycarbodiimide resin, and selected from the group consisting of epoxy resin, phenoxy resin, polyimide resin, (meth)acrylic resin and acrylic rubber At least one of them is more preferable. (C) A component can also be used individually by 1 type or as a 2 or more types of mixture or a copolymer. However, (C)component does not contain the compound applicable to (A) component, and the compound applicable to (D)component.

(C) From a viewpoint that it is excellent in the sticking property to the board|substrate or chip|tip of the film adhesive for semiconductors, as for the glass transition temperature (Tg) of component, 120 degrees C or less is preferable, 100 degrees C or less is more preferable, 85 degrees C or less is more preferable. In the case of these ranges, it is possible to easily fill in unevenness|corrugation, such as a bump formed in a semiconductor chip, an electrode or wiring pattern formed in a board|substrate, with the film adhesive for semiconductors (it is easy to suppress the start of a hardening reaction), and a bubble It is easy to suppress the occurrence of voids by remaining. Here, the above-mentioned Tg is measured using DSC (manufactured by Parkin Elmar Japan, trade name: DSC-7 type) under the conditions of a sample amount of 10 mg, a temperature increase rate of 10°C/min, and a measurement atmosphere: air. is Tg.

(C) As for the weight average molecular weight of component, 10000 or more are preferable in polystyrene conversion, and in order to independently show favorable film formability, 30000 or more are more preferable, 40000 or more are still more preferable, and 50000 or more are especially preferable. When a weight average molecular weight is 10000 or more, it is easy to suppress that film formability falls.

[(D) component: filler]

The flux-free composition may further contain a filler for controlling the viscosity or physical properties of the cured product, and for further suppressing the generation of voids or moisture absorption when a semiconductor chip and a substrate or semiconductor chips are connected. good night. As the component (D), a filler similar to the filler exemplified as the component (e) in the flux-containing composition can be used. Examples of preferred fillers are also the same. Moreover, the preferable range of content of the inorganic filler in (D)component, and the preferable range of content of an insulating filler are also the same.

The content of component (D) is preferably 5 mass % or more, more preferably 10 mass % or more, still more preferably 20 mass % or more, based on the total mass of the flux-free composition. (D) 30 mass % or more or 40 mass % or more may be sufficient as content of a component. (D) When content of component is 5 mass % or more, the amount of expansion with respect to a heat|fever becomes small. In addition, since the expansion of micro voids can be suppressed, connection reliability (particularly, connection reliability when used in an environment such as a temperature cycle test) is more excellent. The content of component (D) is preferably 90 mass % or less, more preferably 80 mass % or less, still more preferably 70 mass % or less, and 60 mass % or less, based on the total mass of the flux-free composition. more preferably. (D) When content of component is 90 mass % or less, since resin is fully excluded at the time of thermocompression bonding, it is excellent in connection reliability. From these viewpoints, the content of component (D) is preferably 5-90 mass%, more preferably 5-80 mass%, still more preferably 10-70 mass%, based on the total mass of the flux-free composition. and 20-60 mass % is still more preferable. (D) 30-90 mass % or 40-80 mass % may be sufficient as content of a component.

[Other Ingredients]

In the flux-free composition, a polymerizable compound other than the radical polymerizable compound (eg, a cationically polymerizable compound and an anionic polymerizable compound) may be blended. Moreover, you may mix|blend other components like a flux containing composition with a flux-free composition. These can be used individually by 1 type or in combination of 2 or more type. About these compounding quantities, what is necessary is just to adjust suitably so that the effect of each additive may be expressed.

As mentioned above, although one embodiment in which the flux-free composition contains a radically polymerizable compound and a thermal radical generator and, if necessary, a polymer component and a filler has been described, the flux-free composition is not limited to the above embodiment.

For example, the flux-free composition comprises the above-mentioned component (a) (epoxy resin) and component (b) (curing agent), and, if necessary, component (d) (a polymer component having a weight average molecular weight of 10000 or more) and component (e) ( filler) may be included. When the flux-free composition is a resin composition containing these components, examples of the component (a), component (b), component (d) and component (e) that can be used, and examples of preferred compounds, are those of the composition containing the flux. same as case For example, the flux-free composition preferably contains an imidazole-based curing agent as a curing agent.

The content of component (a) is, for example, 5 mass% or more, preferably 10 mass% or more, and more preferably 15 mass% or more, based on the total mass of the flux-free composition from the viewpoint of high heat resistance. . The content of the component (a) is, for example, 75 mass% or less, 50 mass% or less, or 45 mass% or less, based on the total mass of the flux-free composition from the viewpoint of film processability.

As for content of (b) component (for example, content of an imidazole type hardening|curing agent), 0.1 mass part or more is preferable with respect to 100 mass parts of (a) component from a viewpoint that sclerosis|hardenability improves. Moreover, 20 mass parts or less are preferable from a viewpoint that a connection defect can be suppressed, and, as for content of (b) component, 10 mass parts is more preferable.

The content of the component (d) is such that the ratio C _a2 /C _d2 (mass ratio) of the content C _a2 of the component (a) to the content C _d2 of the component (d) is 0.01 to 5, 0.05 to 3 or 0.1 to 2 Any amount is fine When the ratio (C _a2 /C _d2 ) is 0.01 or more, better curability and adhesive strength can be obtained, and when the ratio (C _a2 /C _d2 ) is 5 or less, better film formability can be obtained.

The content of the component (e) is preferably 5 mass % or more based on the total mass of the flux-free composition from the viewpoint of better connection reliability (especially connection reliability when used in an environment such as a temperature cycle test) and 10 mass % or more is more preferable, and 20 mass % or more is still more preferable. The content of the component (e) is preferably 80 mass % or less based on the total mass of the flux-free composition, and is preferably 70 mass %, from the viewpoint that the resin can be sufficiently removed at the time of thermocompression bonding and the connection reliability is more excellent. % or less is more preferable, and 60 mass % or less is still more preferable.

The curing reaction rate when the flux-free composition is held at 200°C for 5 seconds is preferably 80% or more, and more preferably 90% or more. When the curing reaction rate at 200°C (below the solder melting temperature)/5 seconds is 80% or more, it is easy to suppress that the solder scatters and flows at the time of connection (above the solder melting temperature), thereby reducing the connection reliability. The curing reaction rate is obtained by placing 10 mg of a flux-free composition (uncured flux-free layer) in an aluminum pan, and then measuring the calorific value using DSC (manufactured by Parkin Elmar Japan, trade name: DSC-7 type). can Specifically, a measurement sample containing 10 mg of a flux-free composition (uncured flux-free layer) placed in an aluminum pan is placed on a hot plate heated to 200° C., and the measurement sample is removed from the hot plate after 5 seconds. The measured sample after heat treatment and the untreated measured sample are respectively measured by DSC. From the obtained calorific value, the curing reaction rate is calculated by the following formula.

Curing reaction rate (%) = (1-[calorific value of measured sample after heat treatment]/[caloric value of untreated measured sample]) x 100

When the flux-free composition contains an anionic polymerizable epoxy resin (especially an epoxy resin having a weight average molecular weight of 10000 or more) together with the component (A), it may be difficult to adjust the curing reaction rate to 80% or more. When the flux-free composition contains component (A), the content of the epoxy resin is preferably 20 parts by mass or less with respect to 80 parts by mass of the component (A), more preferably no epoxy resin.

The adhesive layer (flux-free layer) formed by the flux-free composition can be compressed at a high temperature of 200°C or higher. Further, in a flip chip package in which a connection is formed by melting a metal such as solder, further excellent curability is exhibited.

The film adhesive for semiconductors of this embodiment obtained using the flux containing composition and/or flux non-containing composition demonstrated above has an elasticity modulus in 35 degreeC after hardening of 3.0-5.0 GPa. The elastic modulus of the film adhesive for semiconductors can be adjusted, for example by adjusting the kind and compounding ratio of the component which comprises the film adhesive for semiconductors (for example, the component which comprises a 1st contact bonding layer, and the component which comprises a 2nd contact bonding layer). Specifically, it can be adjusted by, for example, the type and amount of the curable component, the type and amount of the polymer component, the amount of the filler, and the like. In addition, the elastic modulus of the film adhesive for semiconductors can be measured by the method as described in an Example.

The said elastic modulus may be 3.5 GPa or more or 4.0 GPa or more from a viewpoint that the effect of this invention becomes remarkable. The said elastic modulus may be 4.7 GPa or less or 4.4 GPa or less from a viewpoint that the effect of this invention becomes remarkable. That is, the elastic modulus may be 3.0 to 4.7 GPa, 3.0 to 4.4 GPa, 3.5 to 5.0 GPa, 3.5 to 4.7 GPa, 3.5 to 4.4 GPa, 4.0 to 5.0 GPa, 4.0 to 4.7 GPa, or 4.0 to 4.4 GPa.

The filler content of the film adhesive for semiconductors may be 30 mass % or more, 34 mass % or more, or 40 mass % or more on the basis of the total mass of the film adhesive for semiconductors from a viewpoint that the effect of this invention becomes remarkable, Moreover, 60 mass % or less, 50 mass % or less, or 45 mass % or less may be sufficient.

The filler content in one of a 1st contact bonding layer and a 2nd contact bonding layer is 25 mass % or more, 35 mass % or more on the basis of the total mass of the film adhesive for semiconductors from a viewpoint that the effect of this invention becomes remarkable. 45 mass % or more may be sufficient, and 60 mass % or less, 55 mass % or less, or 50 mass % or less may be sufficient. In addition, content of the filler in the other layer among a 1st contact bonding layer and a 2nd contact bonding layer is 5 mass % or more on the basis of the total mass of the film adhesive for semiconductors from a viewpoint that the effect of this invention becomes remarkable, 10 Mass % or more or 15 mass % or more may be sufficient, and 30 mass % or less, 25 mass % or less, or 20 mass % or less may be sufficient.

About the thickness of the film adhesive for semiconductors, when the sum of the heights of the said connection part is made into x and the total thickness of the film adhesive for semiconductors is made into y, the relationship between x and y is the connectivity at the time of crimping|bonding, and an adhesive agent From the viewpoint of filling properties, it is preferable to satisfy 0.70 x ≤ y ≤ 1.3 x, and it is more preferable to satisfy 0.80 x ≤ y ≤ 1.2 x. The total thickness of the film adhesive for semiconductors may be 10-100 micrometers, for example, 10-80 micrometers may be sufficient, and 10-50 micrometers may be sufficient as it.

The thickness of the first adhesive layer (eg, an adhesive layer containing a flux compound) may be, for example, 1 to 50 μm, 3 to 50 μm, 4 to 30 μm, or 5 to 20 μm.

The thickness of the second adhesive layer (eg, the adhesive layer containing no flux compound) may be, for example, 7 to 50 µm, 8 to 45 µm, or 10 to 40 µm.

The ratio of the thickness of the second adhesive layer (e.g., the adhesive layer not containing the flux compound) to the thickness of the first adhesive layer (e.g., the adhesive layer containing the flux compound) (thickness of the second adhesive layer/thickness of the first adhesive layer) is For example, 0.1-10.0 may be sufficient, 0.5-6.0 may be sufficient, and 1.0-4.0 may be sufficient.

Although the film adhesive for semiconductors may further be equipped with other layers other than a 1st contact bonding layer and a 2nd contact bonding layer, it is preferable that only a 1st contact bonding layer and a 2nd contact bonding layer are included. Moreover, on the surface opposite to the 2nd contact bonding layer in a 1st contact bonding layer, and/or on the surface opposite to the 1st contact bonding layer in a 2nd contact bonding layer, the film adhesive for semiconductors of this embodiment is a base film and / or a protective film may be provided.

The film adhesive for semiconductors WHEREIN: A 1st contact bonding layer and a 2nd contact bonding layer may adjoin. In this case, it is preferable that the 1st adhesive layer and the 2nd adhesive layer are formed so that they may not peel from each other. For example, the peel strength between the first adhesive layer and the second adhesive layer may be 10 N/m or more.

(Second embodiment)

The film adhesive for semiconductors of 2nd Embodiment WHEREIN: The elastic modulus in 35 degreeC after hardening may not be 3.0-5.0 GPa. The details of the film adhesive for semiconductors of the second embodiment are, for example, the content of the flux compound, the difference between the filler content in the first adhesive layer and the second adhesive layer, and the like. It may be the same as that of a mold adhesive.

<The manufacturing method of the film adhesive for semiconductors>

The film adhesive for semiconductors of this embodiment prepares, for example, the 1st film adhesive with a 1st adhesive layer, and the 2nd film adhesive with a 2nd adhesive layer, The 1st film adhesive with a 1st adhesive layer, and a 2nd It can obtain by bonding together the 2nd film adhesive with a contact bonding layer.

In the step of preparing a film adhesive (first film adhesive and/or second film adhesive) having, as an adhesive layer, an adhesive layer formed of a flux-containing composition (adhesive layer containing a flux-containing composition), for example, first (a ) component, (b) component and (c) component, and other components such as (d) component and (e) component added as necessary are added in an organic solvent, and dissolved or dispersed by stirring, mixing, kneading, etc. , a resin varnish (coating varnish) is prepared. Then, on the base film subjected to the release treatment, a resin varnish is applied using a knife coater, a roll coater, an applicator, etc., and then the organic solvent is reduced by heating, and the adhesive layer containing the flux-containing composition on the base film can form.

As an organic solvent used for preparation of a resin varnish, it is preferable to have the characteristic which can melt|dissolve or disperse|distribute each component uniformly, For example, dimethylformamide, dimethylacetamide, N-methyl-2- pyrrolidone, dimethyl sulfoxide. , diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone and ethyl acetate. . These organic solvents can be used individually or in combination of 2 or more types. Stirring mixing and kneading at the time of preparing the resin varnish can be carried out using, for example, a stirrer, a rocker, three rolls, a ball mill, a bead mill, or a homodisper.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized, and polyolefin films such as polypropylene films and polymethylpentene films, polyethylene terephthalate films, polyethylene naphthalate films A polyester film, a polyimide film, and a polyetherimide film can be illustrated. A base film is not limited to what became a single layer containing these films, The multilayer film containing 2 or more types of materials may be sufficient.

It is preferable that the drying conditions at the time of volatilizing an organic solvent from the resin varnish apply|coated to the base film make it into conditions that an organic solvent fully volatilizes, Specifically, it is preferable to perform heating for 50-200 degreeC and 0.1-90 minutes. do. If there is no influence on the void or viscosity adjustment after mounting, it is preferable that an organic solvent is removed to 1.5 mass % or less with respect to 1st film adhesive whole quantity.

In the process of preparing a film adhesive (first film adhesive and/or second film adhesive) having an adhesive layer (adhesive layer comprising a flux-free composition) formed by a flux-free composition as an adhesive layer, for example, ( Using other components such as A) component and (B) component, and (C) component added as necessary, or (a) component and (b) component, and other components such as (d) component as necessary Otherwise, the adhesive layer including the flux-free composition may be formed on the base film by the same method as the first adhesive layer.

As a method of bonding a 1st film adhesive and a 2nd film adhesive, methods, such as a hot press, roll lamination, and vacuum lamination, are mentioned, for example. Lamination may be performed under heating conditions of 30-120 degreeC, for example.

After the film adhesive for semiconductors of this embodiment forms one of a 1st contact bonding layer or a 2nd contact bonding layer on a base film, for example, on the obtained 1st contact bonding layer or 2nd contact bonding layer, the other of a 1st contact bonding layer or a 2nd contact bonding layer It may be obtained by forming a side. You may form a 1st contact bonding layer and a 2nd contact bonding layer by the method similar to the formation method of the 1st contact bonding layer and 2nd contact bonding layer in manufacture of the film adhesive with a base material mentioned above.

<Semiconductor device>

The semiconductor device of this embodiment is demonstrated below using FIG.1 and FIG.2. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows one Embodiment of the semiconductor device of this invention. As shown in FIG. 1A , the semiconductor device 100 includes a semiconductor chip 10 and a substrate (circuit wiring board) 20 that oppose each other, and the semiconductor chip 10 and the substrate 20 are mutually opposite each other. Between the wiring 15 arranged on opposite surfaces, the connection bump 30 which interconnects the wiring 15 of the semiconductor chip 10 and the board|substrate 20, respectively, and the semiconductor chip 10 and the board|substrate 20 has a sealing portion 40 comprising a cured product of an adhesive (eg, a composition containing flux and a composition containing no flux) filled without gaps in the pores of the ? The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wiring 15 and the connection bump 30 . The wiring 15 and the connection bump 30 are sealed with a cured product of an adhesive, and are shielded from the external environment. The seal 40 has an upper portion 40a comprising a cured product of the flux-containing composition or flux-free composition, and a lower portion 40b comprising a cured product of the flux-containing composition or flux-free composition. . The upper portion 40a and the lower portion 40b include cured products of different thermosetting resin compositions.

As shown in FIG. 1(b) , the semiconductor device 200 includes a semiconductor chip 10 and a substrate 20 that are opposed to each other, and surfaces of the semiconductor chip 10 and the substrate 20 that are opposed to each other, respectively. A sealing portion 40 comprising the disposed bumps 32 and a cured product of an adhesive (eg, a flux-containing composition and a flux-free composition) filled in the gap between the semiconductor chip 10 and the substrate 20 without a gap. has a The semiconductor chip 10 and the board|substrate 20 are flip-chip-connected by mutually connecting the bump 32 which opposes. The bumps 32 are sealed with a cured product of an adhesive, and are shielded from the external environment. The seal 40 has an upper portion 40a comprising a cured product of the flux-containing composition or flux-free composition, and a lower portion 40b comprising a cured product of the flux-containing composition or flux-free composition. . The upper portion 40a and the lower portion 40b include cured products of different thermosetting resin compositions.

Fig. 2 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention. As shown in FIG. 2A , the semiconductor device 300 is a semiconductor device except that two semiconductor chips 10 are flip-chip connected by a wiring 15 and a connection bump 30 . (100) has the same shape. As shown in FIG. 2B , the semiconductor device 400 has the same shape as the semiconductor device 200 except that the two semiconductor chips 10 are flip-chip connected by bumps 32 . to be.

The semiconductor chip 10 is not particularly limited, and an elemental semiconductor composed of the same type of element such as silicon or germanium, or a compound semiconductor such as gallium arsenide or indium phosphorus can be used.

The substrate 20 is not particularly limited as long as it is a circuit board, and unnecessary portions of the metal film are etched on the surface of the insulating substrate containing glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, etc. as a main component. A circuit board having a wiring (wiring pattern) 15 formed by removing, a circuit board having a wiring 15 formed on the surface of the insulating substrate by metal plating or the like, and a wiring 15 by printing a conductive material on the surface of the insulating substrate The formed circuit board or the like can be used.

The interconnection portion of the wiring 15 and the bump 32 and the like have gold, silver, copper, and solder as main components (the main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.) ), nickel, tin, lead, and the like, and may contain a plurality of metals.

Among the above metals, gold, silver, and copper are preferable, and silver and copper are more preferable from the viewpoint of providing a package excellent in electrical conductivity and thermal conductivity of the connection portion. From a viewpoint of setting it as a cost-reduced package, silver, copper, and solder which are inexpensive materials are preferable, copper and solder are more preferable, and solder is still more preferable. When an oxide film is formed on the surface of a metal at room temperature, productivity may decrease and cost may increase. , solder is more preferable, and gold and silver are still more preferable.

Gold, silver, copper, solder (the main component is, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, etc.), tin, nickel, etc. are mainly used on the surfaces of the wiring 15 and the bump 32. The metal layer used as a component may be formed by plating, for example. This metal layer may be comprised only by a single component, or may be comprised by several components. In addition, the said metal layer may have a single layer or the structure in which several metal layers were laminated|stacked.

In the semiconductor device of the present embodiment, a plurality of structures (packages) as shown in the semiconductor devices 100 to 400 may be stacked. In this case, the semiconductor devices 100 to 400 include gold, silver, copper, solder (the main component is, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), tin, They may be electrically connected to each other by bumps, wirings, or the like containing nickel or the like.

As a method of stacking a plurality of semiconductor devices, as shown in FIG. 3 , for example, a TSV (Through-Silicon Via) technique is used. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention, and is a semiconductor device using TSV technology. In the semiconductor device 500 shown in FIG. 3 , the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor chip 10 via the connection bump 30 , so that the semiconductor chip 10 is ) and the interposer 50 are flip-chip connected. The gap between the semiconductor chip 10 and the interposer 50 is filled with a cured product of an adhesive (eg, a flux-containing composition and a flux-free composition) without a gap, and constitutes the sealing part 40 . On the surface of the semiconductor chip 10 opposite to the interposer 50 , the semiconductor chip 10 is repeatedly laminated through the wiring 15 , the connection bump 30 , and the sealing portion 40 . The wirings 15 on the patterned surface on the front and back of the semiconductor chip 10 are interconnected by through electrodes 34 filled in holes penetrating the inside of the semiconductor chip 10 . In addition, as a material of the through electrode 34, copper, aluminum, etc. can be used.

With this TSV technology, it becomes possible to acquire a signal even from the back surface of a semiconductor chip that is not normally used. Furthermore, since the through electrode 34 is vertically passed through the semiconductor chip 10, the distance between the opposing semiconductor chips 10 and between the semiconductor chip 10 and the interposer 50 is shortened, so that flexible connection is possible. The film adhesive for semiconductors of this embodiment is such a TSV technique. WHEREIN: Between the semiconductor chips 10 which oppose, and between the semiconductor chip 10 and the interposer 50, it is applicable as a film adhesive for semiconductors. .

In addition, in a bump forming method with a high degree of freedom, such as an area bump chip technology, the semiconductor chip can be directly mounted on the motherboard without going through an interposer. The film adhesive for semiconductors of this embodiment is applicable also when mounting such a semiconductor chip directly on a motherboard. In addition, when laminating|stacking two wiring circuit boards, the film adhesive for semiconductors of this embodiment is applicable also when sealing the space|gap between board|substrates.

<Method for manufacturing semiconductor device>

Regarding the manufacturing method of the semiconductor device of this embodiment, the case where the first adhesive layer is an adhesive layer formed of a flux-containing composition and the second adhesive layer is an adhesive layer formed of a flux-free composition is described using FIG. 4 as an example. . However, even when the thermosetting resin composition forming the first adhesive layer and the second adhesive layer are different, the semiconductor device can be manufactured in the same manner.

Fig. 4 is a diagram schematically showing one embodiment of a method for manufacturing a semiconductor device of the present invention, and Figs. 4(a), 4(b), and 4(c) showing respective steps of the semiconductor device are shown in Figs. shows the cross section.

First, as shown in Fig. 4(a) , on the substrate 20 having the wiring 15 , a solder resist 60 having an opening is formed at a position where the connection bump 30 is formed. The solder resist 60 is not necessarily formed. However, by forming a soldering resist on the board|substrate 20, generation|occurrence|production of the bridge|bridging between the wiring 15 can be suppressed and connection reliability and insulation reliability can be improved. The solder resist 60 can be formed using, for example, a commercially available ink for a solder resist for a package. Specific examples of commercially available ink for soldering resists for packages include SR series (manufactured by Hitachi Chemical Co., Ltd., trade name) and PSR4000-AUS series (manufactured by Taiyo Industries, Ltd., trade name).

Next, as shown to Fig.4 (a), the connection bump 30 is formed in the opening of the soldering resist 60. As shown in FIG. Then, as shown in Fig. 4(b), on the substrate 20 on which the connection bumps 30 and the solder resist 60 are formed, the surface on the side of the second adhesive layer 41b containing the flux-free composition is The film adhesive for semiconductors of this embodiment (henceforth, it may be called "film adhesive" in some cases.) 41 of this embodiment is attached so that it may become the board|substrate 20 side. The film adhesive 41 can be pasted by hot press, roll lamination, vacuum lamination, or the like. The supply area and thickness of the film adhesive 41 are suitably set according to the size of the semiconductor chip 10 and the board|substrate 20, the height of the connection bump 30, etc. In addition, you may perform sticking of the film adhesive 41 so that the surface by the side of the 1st contact bonding layer 41a containing a flux containing composition may become the board|substrate 20 side.

After attaching the film adhesive 41 to the substrate 20 as described above, the wiring 15 of the semiconductor chip 10 and the connecting bump 30 are connected to each other using a connecting device such as a flip chip bonder, and the position is fixed. match Next, the semiconductor chip 10 and the substrate 20 are compressed while heating at a temperature equal to or higher than the melting point of the connection bump 30, and as shown in FIG. 4(c), the semiconductor chip 10 and the substrate 20 are bonded together. With the connection box, the space|gap between the semiconductor chip 10 and the board|substrate 20 is sealingly filled with the sealing part 40 containing the hardened|cured material of the film adhesive 41. As described above, the semiconductor device 600 can be obtained.

The crimping time may be, for example, 5 seconds or less. In this embodiment, since the film adhesive 41 of this embodiment mentioned above is used, even if crimping|compression-bonding time is 5 second or less, the semiconductor device which has the outstanding connection reliability can be obtained.

In the manufacturing method of the semiconductor device of this embodiment, after alignment, it temporarily fixes (state through the film adhesive for semiconductors) and heat-processes with a reflow furnace, the connection bump 30 is melted, and the semiconductor chip 10 ) and the substrate 20 may be connected. Since the formation of a metal joint is not necessarily required in the temporary fixing step, compared to the above-described method of pressing while heating, compression by low load, short time, and low temperature may be used, and the productivity can be improved and deterioration of the connection can be suppressed. have.

Moreover, after connecting the semiconductor chip 10 and the board|substrate 20, you may heat-process in an oven etc., and may further improve connection reliability and insulation reliability. The temperature to which hardening of a film adhesive advances is preferable, and, as for heating temperature, the temperature to harden|cure completely is more preferable. The heating temperature and heating time are appropriately set.

In the manufacturing method of the semiconductor device of this embodiment, after attaching the film adhesive 41 to the semiconductor chip 10, you may connect the board|substrate 20.

After supplying the film adhesive for semiconductors to the semiconductor wafer to which the some semiconductor chip 10 was connected from a viewpoint that productivity improves, by dicing and dividing into pieces, it is on the semiconductor chip 10 for semiconductors You may obtain the structure to which the film adhesive was supplied. What is necessary is just to supply the film adhesive for semiconductors so that wiring, bumps, etc. on the semiconductor chip 10 may be embedded, for example by attaching methods, such as hot press, roll lamination, and vacuum lamination. In this case, since the supply amount of resin becomes constant, productivity is improved, and generation|occurrence|production of a void and the fall of dicing property by lack of embedding can be suppressed.

The connection load is set in consideration of variations in the number and height of the connection bumps 30 , the connection bumps 30 due to pressurization, or the amount of deformation of the wiring receiving the bumps in the connection part. As for the connection temperature, although it is preferable that the temperature of a connection part is more than the melting|fusing point of the connection bump 30, it is good as long as it is the temperature at which the metal junction of each connection part (bump and wiring) is formed. When the connection bump 30 is a solder bump, about 240 degreeC or more is preferable.

Although the connection time at the time of connection changes with the constituent metals of a connection part, from a viewpoint that productivity improves, the shorter time is preferable. When the connection bump 30 is a solder bump, 20 second or less is preferable, as for the connection time, 10 second or less is more preferable, and 5 second or less is still more preferable. In the case of copper-copper or copper-gold metal connection, the connection time is preferably 60 seconds or less.

Also in the flip-chip connection part of the various package structure mentioned above, the film adhesive for semiconductors of this embodiment shows the outstanding reflow resistance and connection reliability.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to the said embodiment.

Example

Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to an Example.

<Production of single-layer films A and B>

The compounds used to prepare the monolayer film A with the flux-containing layer and the single-layer film B with the flux-free layer are shown below.

(a) epoxy resin

・Multifunctional solid epoxy containing triphenolmethane skeleton (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jER1032H60)

Bisphenol F-type liquid epoxy (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jERYL983U)

(b) curing agent

2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name: 2MAOK -PW)

(c) flux compound

・Glutaric acid (manufactured by Tokyo Chemical Co., Ltd., melting point about 98°C)

· 2-methylglutaric acid (manufactured by Sigma-Aldrich, melting point about 78°C)

(d) polymer component

・Phenoxy resin (manufactured by Toto Chemical Co., Ltd., trade name: ZX1356-2, Tg: about 71°C, weight average molecular weight Mw: about 63000)

(e) filler

Silica filler (manufactured by Admatex Co., Ltd., trade name: SE2050, average particle diameter: 0.5 μm)

・Epoxysilane surface treatment filler (manufactured by Admatex, Ltd., trade name: SE2050-SEJ, average particle diameter: 0.5 μm)

・Methacryl surface treatment nano silica filler (manufactured by Admatex, Ltd., trade name: YA050C-MJE, average particle diameter: about 50 nm)

・Organic filler (resin filler, manufactured by Rohm & Haas Japan Co., Ltd., EXL-2655: core shell type organic fine particles)

In the preparation of the single-layer film A, the epoxy resin, curing agent, flux compound, polymer component, and filler in the amounts (unit: parts by mass) shown in Table 1 were mixed with NV value ([mass of coating material after drying] / [mass of coating material before drying] ] x 100) was added to an organic solvent (methyl ethyl ketone) to 50%. Thereafter, the beads of Φ 1.0 mm and the beads of Φ 2.0 mm are subjected to the same mass as the solid content (epoxy resin, curing agent, flux compound, polymer component, and filler), and a bead mill (Pritu Japan Co., Ltd., planetary pulverizer P) -7) and stirred for 30 minutes. After stirring, the beads were removed by filtration to prepare a coating varnish. In preparation of the single-layer film B, except not using the flux compound, it carried out similarly to the case of the said single-layer film A, and produced the coating varnish.

The obtained coating varnish was coated on a base film (manufactured by Teijin DuPont Film Co., Ltd., trade name: Purex A54) with a compact precision coating device (Yasui Seiki), and dried in a clean oven (manufactured by ESPEC Corporation). (80°C/10 min), the single-layer films (A-1), (A-2), (A-3), (A-4), (B-1) and (BB-2) shown in Table 1) got The thickness of the flux-containing layer in the single-layer film A and the thickness of the flux-free layer in the single-layer film B were both 20 µm.

<Production of single-layer film C>

The compounds used for the preparation of the single-layer film C with the flux-free layer are shown below.

(A) (meth)acrylic compound

-Acrylates having a fluorene-type skeleton (manufactured by Osaka Chemical Co., Ltd., trade name: EA-0200, bifunctional groups)

(B) thermal radical generator

・Dicumyl peroxide (manufactured by Nichi Yu, Ltd., trade name: Percumyl (registered trademark) D)

· 1,4-bis-((tert-butylperoxy)diisopropyl)benzene (manufactured by Nichi Oil Co., Ltd., trade name: perbutyl (registered trademark) P)

(C) polymer component

・Acrylic resin (manufactured by Hitachi Chemical Co., Ltd., trade name: KH-CT-865, weight average molecular weight Mw: 100000, Tg: 10°C)

(D) filler

The same filler (component (e)) used for preparation of the single-layer films A and B was used.

The (meth)acrylic compound, the polymer component, and the filler of the compounding quantity (unit: mass part) shown in Table 1 were added to the organic solvent (methyl ethyl ketone) so that an NV value might become 50%. Then, the same mass of the Φ 1.0 mm bead and the Φ 2.0 mm bead as the solid content ((meth)acrylic compound, polymer component and filler) was added, and a bead mill (manufactured by Freechu Japan, Ltd., planetary fine pulverizer P- 7) and stirred for 30 minutes. After stirring, the beads were removed by filtration. Next, the thermal radical generator was added to the obtained mixture, it stirred and mixed, and the coating varnish was produced.

The obtained coating varnish was coated on a base film (manufactured by Teijin DuPont Film Co., Ltd., trade name: Purex A54) with a small precision coating device (manufactured by Yasui Seiki Co., Ltd.), and a clean oven (ESPEC, Ltd.) production) and dried (80° C./10 min) to obtain single-layer films (C-1), (C-2), (C-3) and (C-4) shown in Table 1. The thickness of the flux-free layer in the single-layer film C was all set to 20 µm.

<Production of two-layer film>

(Examples 1 to 6 and Comparative Examples 1 to 4)

Among the single layer films produced above, the same or different two films were laminated at 50 degreeC, and the film adhesive with a total thickness of 40 micrometers was produced. The single-layer film combinations were as shown in Table 1. In addition, when the same film is used, since the 2nd adhesive layer does not exist, Table 1 has shown only the 1st adhesive layer.

<Evaluation>

By the method shown below, about the film adhesive obtained by the Example and the comparative example, and the semiconductor device produced using this film adhesive, elastic modulus measurement, chip warp evaluation, initial stage connectivity evaluation, void evaluation, and temperature cycle test evaluation did A result is shown in Table 1.

(Measurement of modulus of elasticity)

A test sample was obtained by cutting out the film adhesive obtained in an Example or a comparative example to a predetermined size (40 mm in height x 4.0 mm in width x 0.06 mm in thickness), and curing it in a clean oven (made by ESPEC Corporation). Cure conditions were 240 degreeC and 1 hour.

The elastic modulus of the test sample was measured using a dynamic viscoelasticity measuring apparatus (manufactured by BM Co., Ltd., trade name: Rheogel-E4000).

(Evaluation of chip warpage)

The film adhesive obtained in Examples or Comparative Examples was subjected to a silicon chip (length 10 mm×width 10 mm×thickness 0.05 mm, oxide film coating) using a vacuum laminator (manufactured by Corporation Corporation, trade name: LM-50X50-S). laminated on top. Next, the sample which laminated the film adhesive was cured in a clean oven (made by ESPEC Corporation), and the test sample was obtained. Cure conditions were 240 degreeC and 1 hour.

Moire measurement was performed using a 3D heating surface shape measuring device Thermoray PS200S (manufactured by acrometrix), and the result of warpage was defined as “A”, and that of 130 μm or more and less than 150 μm as “B”. And, the thing 150 micrometers or more was made into "C", and chip|tip curvature was evaluated. Specifically, the warpage of the test sample was measured by installing the test sample under the glass with vertical stripes, applying light from an oblique direction, measuring and analyzing the interference stripes with a camera.

(Evaluation of initial connectivity)

The film adhesive produced in the Example or the comparative example was cut out to predetermined size (8 mm long x 8 mm wide x 40 micrometers in thickness), and the sample for evaluation was produced. Next, a sample for evaluation was affixed on a glass epoxy substrate (glass epoxy substrate: 420 μm thick, copper wiring: 9 μm thick), and a semiconductor chip having solder bumps (chip size: 7.3 mm long × 7.3 mm wide × 0.15 thick) mm, bump height: about 40 µm in total of copper pillars + solder, the number of bumps 328) was mounted with a flip mounting device “FCB3” (manufactured by Panasonic Corporation, trade name). The mounting conditions were a crimping head temperature of 350°C, a crimping time of 3 seconds, and a crimping pressure of 0.5 MPa. Thereby, similarly to FIG. 4, the semiconductor device in which the said glass epoxy board|substrate and the semiconductor chip with solder bumps were daisy-chain-connected was produced. In addition, the samples for evaluation of Examples 1-5 and Comparative Examples 1 and 4 were affixed on the glass substrate so that a 2nd contact bonding layer and a glass epoxy substrate might contact.

The initial conduction after mounting was evaluated by measuring the connection resistance value of the obtained semiconductor device using the multimeter (made by a corporation|Co., Ltd.|KK Advanced, brand name: R6871E). When the connection resistance is 10.0 Ω or more and 13.5 Ω or less, the connection resistance is “A” (good), and when the connection resistance is greater than 13.5 Ω and 20 Ω or less, the connection resistance is “B” (bad), and the connection resistance is 20 Ω When larger, the case where a connection resistance value was less than 10 ohms and the case where a resistance value was not displayed by connection defect were all evaluated as connection "C" (defect).

(Void evaluation)

Regarding the semiconductor device manufactured by the above method, an external image was taken with an ultrasonic imaging device (trade name: Insight-300, manufactured by Insight Co., Ltd.), and a scanner GT-9300UF (manufactured by Seiko Epson, Ltd., brand name) was taken. Acquire the image of the adhesive part on the raw chip (the part containing the hardened|cured material of the film adhesive for semiconductors), and identify the void part by color tone correction and gradation using image processing software Adobe Photoshop (trademark), , the percentage occupied by the void portion was calculated from the histogram. Let the area of the adhesive part on the chip be 100%, the case where the void generation rate is 5% or less is "A", the case where it is more than 5% and 10% or less is "B", and the case where it is more than 10% is "C" was evaluated as

(Temperature cycle test evaluation (TCT resistance evaluation))

The semiconductor device produced by the above method was molded under conditions of 180°C, 6.75 MPa, and 90 seconds using a sealing material (manufactured by Hitachi Chemical Co., Ltd., trade name: CEL9750ZHF10). Next, in a clean oven (manufactured by ESPEC Corporation), aftercure was performed on condition of 175°C and 5 hours to obtain a package. Next, this package was connected to a cold-heat cycle tester (manufactured by Kusumoto Chemical Co., Ltd., trade name: THERMAL SHOCK CHAMBER NT1200), and a 1 mA current was passed, 25°C for 2 minutes/-55°C for 15 minutes/25°C 2 Minutes/125 degreeC 15 minutes/25 degreeC 2 minutes were made into 1 cycle, and the change of connection resistance after 1000 cycles was evaluated. Compared with the initial resistance value waveform, the case where there was no significant change even after 1000 cycles (no difference or a difference of less than 1 Ω) was defined as “A”, and the case where a difference of 1 Ω or more occurred was defined as “B”.

As for the film adhesive for semiconductors of an Example, curvature was reduced, void generation|occurrence|production was fully suppressed, electrical connection property was favorable, and it was confirmed that it was excellent in electrical connection property even after a temperature cycle test.

10: semiconductor chip
15: wiring (connection part)
20: board (wiring circuit board)
30: connection bump
32: bump (connection part)
34: through electrode
40: seal
41: film adhesive for semiconductor
50: interposer
60: solder resist
100, 200, 300, 400, 500, 600: semiconductor devices.

Claims (18)

A thermosetting adhesive layer comprising a first adhesive layer and a second adhesive layer provided on the first adhesive layer, wherein one of the first adhesive layer and the second adhesive layer is a thermosetting adhesive layer containing a flux compound, the other of the first adhesive layer and the second adhesive layer one side is a thermosetting adhesive layer containing no flux compound,
The thermosetting adhesive layer containing no flux compound contains an epoxy resin and a latent curing agent,
The film adhesive for semiconductors whose elastic modulus in 35 degreeC after hardening is 3.0-5.0 GPa. As a film adhesive for semiconductors containing a filler,
A thermosetting adhesive layer comprising a first adhesive layer and a second adhesive layer provided on the first adhesive layer, wherein one of the first adhesive layer and the second adhesive layer is a thermosetting adhesive layer containing a flux compound, the other of the first adhesive layer and the second adhesive layer one side is a thermosetting adhesive layer containing no flux compound,
The thermosetting adhesive layer that does not contain the flux compound contains an epoxy resin and a latent curing agent,
The film adhesive for semiconductors whose content of the said filler is 30-60 mass % on the basis of the total mass of the film adhesive for semiconductors. delete delete delete The film adhesive for semiconductors according to claim 1 or 2, wherein the flux compound has a carboxyl group. The film adhesive for semiconductors according to claim 1 or 2, wherein the flux compound has two or more carboxyl groups. The film adhesive for semiconductors according to claim 1 or 2, wherein the flux compound is a compound represented by the following formula (2):

[In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, and n represents 0 or an integer of 1 or more. A plurality of R ² may be the same or different from each other.] The film adhesive for semiconductors of Claim 1 or 2 whose melting|fusing point of the said flux compound is 150 degrees C or less. delete delete delete delete delete delete The film adhesive for semiconductors according to claim 1 or 2, wherein the latent curing agent is an imidazole-based curing agent. A method of manufacturing a semiconductor device in which respective connecting portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which respective connecting portions of a plurality of semiconductor chips are electrically connected to each other, comprising:
The manufacturing method of a semiconductor device provided with the process of sealing at least one part of the said connection part using the film adhesive for semiconductors of Claim 1 or 2. A semiconductor device in which respective connecting portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which respective connecting portions of a plurality of semiconductor chips are electrically connected to each other, comprising:
The semiconductor device in which at least one part of the said connection part is sealed with the hardened|cured material of the film adhesive for semiconductors of Claim 1 or 2.

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