JP5137538B2 - Adhesive composition, adhesive sheet and method for producing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet, capable of holding adhesiveness onto a chip reverse face even when exposed to a high temperature and high humidity, and exhibiting excellent moisture resistance even when exposed to the high temperature and high humidity under the impression of a voltage. <P>SOLUTION: This pressure-sensitive adhesive composition contains an acrylic polymer, a compound having a functional group reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule, an epoxy thermosetting resin, and an ion scavenger. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a step of die-bonding a semiconductor element (semiconductor chip) on a substrate or another semiconductor chip, and dicing a silicon wafer or the like and dicing the semiconductor chip on the substrate or another semiconductor chip. Adhesive composition particularly suitable for so-called chip stack used in the bonding step, an adhesive sheet having an adhesive layer comprising the adhesive composition, and the adhesive composition The present invention relates to a semiconductor device (especially a stack-type semiconductor device) using the above and a manufacturing method thereof.

  A semiconductor wafer made of silicon, gallium arsenide or the like is manufactured in a large diameter state, and this wafer is cut and separated (diced) into element pieces (semiconductor chips) and then transferred to the next mounting step. At this time, the semiconductor wafer is subjected to dicing, cleaning, drying, expanding, and pick-up processes in a state where it is adhered to the adhesive sheet in advance, and then transferred to the next bonding process.

  In order to simplify the processes of the pick-up process and the bonding process among these processes, various dicing / die bonding adhesive sheets having both a wafer fixing function and a die bonding function have been proposed (for example, Patent Documents 1 to 4). Such a pressure-sensitive adhesive sheet enables so-called direct die bonding, and the application process of the liquid die bonding adhesive can be omitted.

  On the other hand, there is a “stacked semiconductor device” in which semiconductor chips are three-dimensionally stacked in order to increase the speed and size of the semiconductor device. As such an apparatus, a type in which a small chip is stacked on a large chip (see Japanese Patent Laid-Open No. 7-38053), a type in which a chip in which a step is formed in the peripheral portion is stacked (see Japanese Patent Laid-Open No. 6-244360), There has been proposed a type in which two chips are bonded back to back, one chip is bonded to the substrate, and the other chip is bonded to the substrate with a bonding wire (see Japanese Patent Laid-Open No. 7-273275).

  In addition, in the bonding between the stacked chips of these stack type semiconductor devices, the dicing / bonding adhesive is more suitable than the liquid die attach adhesive in terms of the quality of the semiconductor devices (chip stacking height variation and chip inclination) and productivity. Die bonding sheets are widely used. In many cases, the adhesive of the dicing die bonding sheet contains an epoxy resin thermosetting resin and a curing agent for the epoxy resin as a component that develops the adhesive force. From the viewpoint of productivity, amine curing agents and phenol resin curing agents are used as curing agents.

  As the main component of the adhesive, an epoxy resin and an acrylic polymer are generally used, but as the ionic impurity, a residue of a chlorine-containing compound as a raw material is mixed in the epoxy resin.

In order to reduce the concentration of these ionic impurities, an adhesive containing an ion scavenger has been conventionally used as an adhesive for semiconductors (for example, Patent Documents 5 to 6).
JP-A-2-32181 JP-A-8-239636 Japanese Patent Laid-Open No. 10-8001 JP 2000-17246 A JP-A-62-195069 JP-A-5-121465

  Incidentally, the required characteristics for semiconductor devices are very strict. For example, package reliability under severe wet heat environments is required. However, as a result of the thinning of the semiconductor chip itself, the strength of the chip is reduced, and it cannot be said that the package reliability in a severe wet heat environment is sufficient.

  The stack type semiconductor device package is required to have not only the adhesion reliability of the layer that bonds the substrate and the chip but also the adhesion reliability of the layer that bonds the chip to be stacked and the chip. In particular, the back surface of the upper chip is subjected to various stress reliefs such as dry polishing and CMP, and the smoothness is remarkably improved as compared with conventional wafer grinding surfaces. For this reason, it has become difficult for conventional adhesives to maintain sufficient adhesion to the back surface of the chip, resulting in a problem of reduced adhesion to the back surface of the chip.

  Furthermore, in recent years, a surface mounting method (reflow) in which the entire package is exposed to a high temperature equal to or higher than the solder melting point is performed in the surface mounting method used for connecting electronic components. Recently, due to environmental considerations, the transition to solder containing no lead has raised the maximum temperature during mounting from the conventional 230-240 ° C to 260-265 ° C, increasing the stress generated inside the semiconductor package. Further, the risk of peeling of the adhesive interface and package cracking is further increased.

  In the state-of-the-art semiconductor element, copper is being used in the circuit and pad portion of the silicon chip instead of the conventional aluminum alloy. This is because copper has the characteristics that the resistivity is smaller than that of the aluminum alloy and a high-density current can flow. However, as a result of the use of copper, in an environment where voltage is applied under high temperature and high humidity, corrosion of wiring and pads due to electrolytic corrosion has become more obvious than when aluminum alloys are used. Specifically, in a stacked semiconductor device formed by connecting a wire on a semiconductor chip and bonding another semiconductor chip of the same size as this semiconductor chip so as to embed the wire, by leaving it at high temperature and high humidity, The ionic impurities in the adhesive are dissolved in the absorbed water, and as a result, the insulation resistance value of the adhesive layer is lowered. Therefore, the insulation between the wires embedded in the adhesive layer cannot be maintained, and in the worst case, a short circuit occurs. The durability under this high temperature and high humidity environment can be evaluated by HAST (Highly-Accelerated Temperature and Humidity Stress Test).

  The above-described adhesive containing the ion scavenger disclosed in Patent Documents 5 and 6 greatly contributes to improvement of moisture resistance reliability when no voltage is applied. However, this method does not necessarily improve the package reliability (HAST resistance) when a voltage is applied in a high temperature and high humidity environment.

As described above, the thinning of the semiconductor chip, the accompanying smoothness of the chip grinding surface and the increase in the mounting temperature, and the application of copper to the semiconductor wiring material have led to a decrease in the reliability of the package and are becoming stricter. With respect to the reliability of semiconductor packages, conventional adhesives cannot meet the required level.
For this reason, in a package mounted with a semiconductor chip that is becoming thinner, even when exposed to severe reflow conditions, there is no peeling of the adhesive interface or generation of package cracks. It is required to realize high package reliability that does not corrode aluminum alloy and copper wiring and pads even when exposed to humidity.

  The present invention has been made in view of the above circumstances, and even when exposed to high temperature and high humidity, adhesion to the back surface of the chip is kept high, and exposure to high temperature and high humidity is performed under application of voltage. It is an object of the present invention to provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet that are excellent in moisture resistance even in such a case, a stacked semiconductor device using the pressure-sensitive adhesive composition, and a method for manufacturing the same.

  As a result of intensive studies aimed at solving such problems, the present inventors have found that the above object can be achieved by an adhesive composition containing a specific compound capable of reacting with an epoxy group and an ion scavenger. The present invention has been completed.

The gist of the present invention aimed at solving such problems is as follows.
[1] An adhesive composition containing an acrylic polymer, a compound having a functional group capable of reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule, an epoxy thermosetting resin, and an ion scavenger.

[2] The adhesive composition according to [1], wherein the content of the ion scavenger is 1 to 15 parts by weight with respect to a total of 100 parts by weight of all resin components.
[3] An adhesive sheet in which an adhesive layer made of the adhesive composition according to [1] or [2] is formed on a substrate.

  [4] A semiconductor wafer is attached to the adhesive layer of the adhesive sheet according to [3], the semiconductor wafer is diced into semiconductor chips, and an adhesive layer is formed on the back surface of the semiconductor chips. A method for manufacturing a semiconductor device, comprising the steps of: fixing and remaining, peeling from a base material, and thermocompression bonding the semiconductor chip onto a substrate through the adhesive layer.

  [5] A semiconductor wafer is adhered to the adhesive layer of the adhesive sheet according to [3], the semiconductor wafer is diced into semiconductor chips, and an adhesive layer is provided on the back surface of the semiconductor chips. Including a step of allowing the semiconductor chip to be adhered and peeled off from the base material and thermocompression-bonding the semiconductor chip onto another semiconductor chip via the adhesive layer, and a step of fixing these semiconductor chips on the substrate. A method of manufacturing a semiconductor device.

  In a stack type semiconductor device using the adhesive composition of the present invention containing a specific compound capable of reacting with an epoxy group and an ion scavenger for bonding between semiconductor chips or between a semiconductor chip and a substrate The wiring layer can exhibit an excellent adhesive force even when exposed to high temperature and high humidity, and wiring even when exposed to high temperature and high humidity under voltage application There is no corrosion of the pad.

  In a semiconductor device using the adhesive composition of the present invention for bonding between semiconductor chips or between a semiconductor chip and a substrate, there is no peeling at the bonding interface even in a high temperature and high humidity environment. Water entry from the interface can be minimized. As a result, since the rate at which the adhesive composition comes into contact with water is reduced, the amount of ionic impurities that are extracted from the adhesive composition and induce electric corrosion is smaller than before. In addition, ionic impurities are trapped by the ion scavenger. As a result, the semiconductor device using the adhesive composition of the present invention has excellent moisture and heat resistance when a voltage is applied, and is exposed to severe wet heat conditions in a stacked semiconductor package in which semiconductor chips are stacked and mounted in multiple stages. Even so, high package reliability can be achieved.

Hereinafter, the present invention will be described in more detail.
The adhesive composition according to the present invention (hereinafter also simply referred to as “adhesive”) is an acrylic polymer (A) (hereinafter referred to as “acrylic polymer (A)” or “component (A)”). The same applies to other components.) Compound (B) having a functional group capable of reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule (hereinafter referred to as “compound (B)” or “(B) In addition, the epoxy thermosetting resin (C) and the ion scavenger (E) are included as essential components, and other components may be included as necessary in order to improve various physical properties. Hereinafter, each of these components will be described in detail.

(A) an acrylic polymer;
A conventionally well-known acrylic polymer can be used as an acrylic polymer (A). The weight average molecular weight of the acrylic polymer is desirably 10,000 or more and 2 million or less, and more desirably 100,000 or more and 1.5 million or less. If the weight average molecular weight of the acrylic polymer is too low, the adhesive strength with the base material becomes high and pickup failure may occur. If it exceeds 2 million, the adhesive layer may not be able to follow the substrate irregularities. It becomes an occurrence factor.

  The glass transition temperature of the acrylic polymer is preferably in the range of −10 ° C. to 50 ° C., more preferably 0 ° C. to 40 ° C., and particularly preferably 0 ° C. to 30 ° C. If the glass transition temperature is too low, the peeling force between the adhesive layer and the substrate may increase, resulting in chip pick-up failure. If it is too high, the adhesive force for fixing the wafer may be insufficient. There is.

Moreover, as a monomer of this acrylic polymer, a (meth) acrylic acid ester monomer or its derivative is mentioned. For example, the alkyl group has 1 to 18 carbon atoms (meth)
Examples include alkyl acrylates (for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, etc.), and (meth) acrylate esters having a cyclic skeleton ( (Meth) acrylic acid cycloalkyl ester, (meth) acrylic acid benzyl ester, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, imide acrylate, etc.) -Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, glycidyl methacrylate, glycidyl acrylate Doors and the like. Vinyl acetate, acrylonitrile, styrene or the like may be copolymerized.

As the acrylic polymer (A), an acrylic polymer having a hydroxyl group is preferable in terms of good compatibility with the epoxy resin.
(B) a compound having a functional group capable of reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule;
The compound (B) is not particularly limited as long as it has both a functional group capable of reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule. The functional group capable of reacting with an epoxy group is preferably a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group and an acid anhydride, more preferably a phenolic hydroxyl group, an alcoholic hydroxyl group and an amino group, particularly preferably Is a phenolic hydroxyl group. Further, the unsaturated hydrocarbon group is not particularly limited as long as it has energy beam curability, and an ultraviolet curable one is more preferable. Specific examples include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, an acrylamide group, and a methacrylamide group, and more preferably a methacryloyl group and an acrylamide group.

As such a compound (B), for example, a compound obtained by substituting a part of the hydroxyl group of the phenol resin with a group containing an unsaturated hydrocarbon group, or an aromatic ring of the phenol resin contains an unsaturated hydrocarbon group. Examples include compounds in which groups are directly bonded. Here, examples of the phenol resin include a phenol resin (described later) optionally used as a curing agent, and a novolak type phenol resin is particularly preferable. Therefore, as the compound (B), a compound obtained by substituting a part of the hydroxyl group of the novolak type phenol resin with a group containing an unsaturated hydrocarbon group, or an aromatic group of the novolak type phenol resin has an unsaturated hydrocarbon group. A compound in which a group containing is directly bonded is preferable.

  Particularly preferred examples of such a compound (B) include a repeating unit containing a phenolic hydroxyl group such as the following formula (a) and an unsaturated hydrocarbon group such as the following formula (b) or (c). Examples thereof include compounds containing a repeating unit having a containing group.

(Wherein n is 0 or 1)

(In the formula, n is 0 or 1, R ¹ is an optionally substituted hydrocarbon group having 1 to 5 carbon atoms, X is —O—, —NR ² — (R ² is hydrogen or Methyl) or R ¹ X is a single bond and A is an acryloyl group or a methacryloyl group)
The proportion of the repeating unit represented by the formula (a) in the compound is 5 to 95 mol%, more preferably 20 to 90 mol%, particularly preferably 40 to 80 mol%, ) Or (c) The proportion of repeating units represented by the formula is 5 to 95 mol% in total, more preferably 10 to 80 mol%, and particularly preferably 20 to 60 mol%.

  The phenolic hydroxyl group represented by the repeating unit (a) is a functional group capable of reacting with an epoxy group, and serves as a curing agent that reacts and cures with the epoxy group of the epoxy resin (C) when the adhesive is thermally cured. It has a function. Moreover, the unsaturated hydrocarbon group represented by repeating units (b) and (c) improves the compatibility between the acrylic polymer (A) and the epoxy thermosetting resin (C). As a result, the cured product of the adhesive becomes tougher, which improves the reliability as an adhesive.

  Furthermore, if the adhesive composition of the present invention is energy ray cured, the unsaturated hydrocarbon group represented by the repeating units (b) and (c) is energy ray cured of the adhesive. It is sometimes polymerized and cured, and has the effect of reducing the adhesive force between the adhesive layer and the substrate.

The number average molecular weight of the compound (B) is preferably 300 to 30000, more preferably 400 to 10000, and particularly preferably 500 to 3000.
(C) Epoxy thermosetting resin;
As the epoxy thermosetting resin (C), conventionally known various epoxy resins are used. The epoxy resin (C) is preferably contained in an amount of 1 to 1500 parts by weight, more preferably 3 to 1000 parts by weight, and still more preferably 100 to 1000 parts by weight with respect to 100 parts by weight of the acrylic polymer (A). If the amount is less than 1 part by weight, sufficient adhesiveness may not be obtained. If the amount exceeds 1500 parts by weight, the peel strength from the substrate may be increased, resulting in pickup failure. On the other hand, when the epoxy resin (C) is used in a weight equal to or greater than that of the acrylic polymer (A), the adhesive composition of the present invention is good in terms of uneven followability and wire embedding.

Examples of the epoxy resin (C) include bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resin (the following formula (1)), dicyclopentadiene type epoxy resin (the following formula (2)), and biphenyl type epoxy. Examples thereof include an epoxy compound having two or more functional groups in the molecule, such as a resin or a biphenyl compound (the following formulas (3) and (4)). These can be used alone or in combination of two or more.

(Where n represents an integer of 0 or more)

(Where n represents an integer of 0 or more)

(Where n represents an integer of 0 or more)

(In the formula, R represents a hydrogen atom or a methyl group.)
(D) a curing agent;
A hardening | curing agent (D) functions as a hardening | curing agent of an epoxy-type thermosetting resin (C) with the said compound (B). In contrast to the case of the compound (B) alone, by using the curing agent (D), it is possible to adjust the physical properties such as adjustment of the rate of the curing reaction and the elastic modulus of the cured product of the adhesive to a preferable region. . Preferred curing agents include compounds having two or more functional groups capable of reacting with an epoxy group in one molecule. The functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydrides. Etc. Of these, phenolic hydroxyl groups, amino groups, acid anhydrides and the like are preferable, and phenolic hydroxyl groups and amino groups are more preferable. Specific examples of these include novolak-type phenol resins represented by the following formula (5), dicyclopentadiene-based phenol resins represented by the formula (6), polyfunctional phenol resins represented by the formula (7), and the like. Examples thereof include phenolic curing agents, sylock type phenol resins represented by the following formula (8), and amine curing agents such as DICY (dicyandiamide). These curing agents can be used alone or in combination of two or more.

  The amount of the compound (B) and the curing agent (D) used is 0.1 to 500 parts by weight in total of (B) + (D) with respect to 100 parts by weight of the epoxy thermosetting resin (C). It is preferably 1 to 100 parts by weight. The ratio (weight ratio) of compound (B) / curing agent (D) is preferably 0.5 or more, more preferably 1 or more, and particularly preferably 2 or more. The compound (B) may be used alone without using the curing agent (D).

  If the total amount of the compound (B) and the curing agent (D) is small, the adhesiveness may not be obtained due to insufficient curing, and if it is excessive, the moisture absorption rate may increase and the reliability of the package may be reduced. Moreover, if the compound (B) / curing agent (D) is small, the effects of the present invention may not be sufficiently obtained.

(Where n represents an integer of 0 or more)

(Where n represents an integer of 0 or more)

(Where n represents an integer of 0 or more)

(In the formula, n represents an integer of 0 or more.)
(E) an ion scavenger;
The ion scavenger (E) used in the present invention has an effect of capturing ions liberated from the adhesive, including chlorine ions that cause corrosion and electrolytic corrosion of wiring and pads of semiconductor devices. Either an adsorption type (porous filler type) or an ion exchange type may be used.

  Examples of the ion adsorption type include ketjen black (carbon black, manufactured by Ketjen, trade name), celite (diatomaceous earth, manufactured by Johns Manville, trade name), and the like. They can be used in combination.

  Examples of the ion exchange type include oxides such as antimony, bismuth, magnesium and aluminum, hydroxides, nitrates and carbonates. These are preferable in that the effect can be obtained with a small amount. Examples thereof preferably include antimony oxide, bismuth oxide, and a mixture thereof, and hydrotalcite that is a magnesium-aluminum oxide and a fired product thereof. Note that Al in the hydrotalcite may be substituted with Cr or Fe.

These can be used individually by 1 type or in mixture of 2 or more types.
The compounding amount of the ion scavenger is preferably 1 to 15 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the total resin components. If the amount is less than 1 part by weight, the ion trapping effect may not be obtained. If the amount is more than 15 parts by weight, the adhesiveness may be deteriorated or the flow characteristics before curing may be changed. The “all resin components” are acrylic polymer (A), compound (B), epoxy thermosetting resin (C) and curing agent (D).

As the ion scavenger (E), a powder having an average particle diameter of 0.01 μm or more and 5 μm or less is preferable, and a powder having an average particle diameter of 0.05 μm or more and 2 μm or less is more preferable.
The adhesive composition according to the present invention contains the acrylic polymer (A), the compound (B), the epoxy thermosetting resin (C), and the ion scavenger (E) as essential components, and has various physical properties. In order to improve this, the said hardening | curing agent (D) or the following component may further be included as needed.

(F) a curing accelerator;
A hardening accelerator (F) is used in order to adjust the cure rate of an adhesive composition. Preferred curing accelerators include compounds that can promote the reaction between an epoxy group and a phenolic hydroxyl group or an amine. Specifically, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris ( Tertiary amines such as (dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine, And tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphinetetraphenylborate. These can be used individually by 1 type or in mixture of 2 or more types.

  It is preferable that 0.01-100 weight part is contained with respect to 100 weight part of epoxy-type thermosetting resins (C), and, as for a hardening accelerator (F), 0.1-50 weight part is more preferable, and 1-30. Part by weight is more preferred.

(G) a coupling agent;
A coupling agent is used in order to improve the adhesiveness and adhesiveness with respect to the adherend of an adhesive composition. Moreover, the water resistance can be improved by using a coupling agent, without impairing the heat resistance of the hardened | cured material obtained by hardening | curing an adhesive composition. As the coupling agent, a compound having a group that reacts with a functional group of the above component (A), component (B), component (C), component (D), or the like is preferably used. As the coupling agent, a silane coupling agent is desirable. Such coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacrylopropyl). ) Trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N- Phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxy Silane, methylto Examples include reethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These can be used individually by 1 type or in mixture of 2 or more types.

When using these coupling agents, it is usually 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the epoxy thermosetting resin (C). Used in proportions. If it is less than 0.1 parts by weight, the effect cannot be obtained, and if it exceeds 20 parts by weight, it may cause outgassing.

(H) a crosslinking agent;
In order to adjust the initial adhesive strength and cohesive strength of the adhesive composition, a crosslinking agent may be added. Examples of the crosslinking agent include organic polyvalent isocyanate compounds and organic polyvalent imine compounds.

Examples of the organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, trimers of these polyvalent isocyanate compounds, And a terminal isocyanate urethane prepolymer obtained by reacting a polyvalent isocyanate compound with a polyol compound. Specific examples of the organic polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylene diisocyanate. Narate, diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4 ′ -Diisocyanate, dicyclohexylmethane-
2,4'-diisocyanate, lysine isocyanate, etc. are mentioned.

Specific examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylol. Mention may be made of methane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxamide) triethylenemelamine and the like.

A crosslinking agent (H) is 0.01-10 weight part normally with respect to 100 weight part of acrylic polymers (A), Preferably it is 0.1-5 weight part, More preferably, it is a ratio of 0.5-3 weight part. Used.
(I) an energy beam polymerizable compound;
When using the photoinitiator (J) mentioned later, an energy ray polymeric compound (J) may be mix | blended with the adhesive layer. Since the adhesive force of the adhesive layer can be reduced by curing the energy beam polymerizable compound (J) together with the compound (B) by energy beam irradiation, the interlayer between the base material and the adhesive layer Peeling can be easily performed.

The energy ray polymerizable compound (I) is a compound that is polymerized and cured when irradiated with energy rays such as ultraviolet rays and electron beams. Specific examples of the energy ray polymerizable compound include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and 1,4-butylene glycol. Acrylate compounds such as diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, polyether acrylate, and itaconic acid oligomer are used. Such a compound has at least one polymerizable double bond in the molecule, and usually has a weight average molecular weight of about 100 to 30,000, preferably about 300 to 10,000.

  When energy ray polymerizable compound (I) is used, it is usually 1 to 40 parts by weight, preferably 3 to 30 parts by weight, more preferably 3 to 20 parts by weight with respect to 100 parts by weight of the acrylic polymer (A). Used in proportions. If it exceeds 40 parts by weight, the adhesiveness of the pressure-sensitive adhesive composition of the present invention to an organic substrate or a lead frame may be lowered.

(J) a photopolymerization initiator;
When using the adhesive composition of the present invention, energy rays such as ultraviolet rays may be irradiated to reduce the adhesive force with the substrate. At this time, by adding the photopolymerization initiator (J) to the composition, the polymerization curing time and the amount of light irradiation (energy ray irradiation amount) can be reduced.

Specific examples of such photopolymerization initiators include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, Examples include 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, β-chloranthraquinone, and the like. A photoinitiator (J) can be used individually by 1 type or in combination of 2 or more types.

The blending ratio of the photopolymerization initiator (J) is theoretically determined based on the amount of unsaturated bonds present in the adhesive and the reactivity thereof and the reactivity of the photopolymerization initiator used. Should be, but not always easy in complex mixture systems. When the photopolymerization initiator (J) is used, as a general guideline, the photopolymerization initiator (J) is used in an amount of 0 with respect to 100 parts by weight of the compound (B) and the energy beam polymerizable compound (I). Desirably 1 to 10 parts by weight are contained, 1
-5 parts by weight is more preferred. When the content is in the above range, satisfactory pickup properties can be obtained. If it exceeds 10 parts by weight, a residue that does not contribute to photopolymerization is generated, and the curability of the adhesive may be insufficient.

(K) inorganic filler;
By blending an inorganic filler into the adhesive, it is possible to adjust the thermal expansion coefficient and optimize the thermal expansion coefficient of the adhesive layer after curing with respect to a semiconductor chip, metal or organic substrate Thus, the heat resistance of the package can be improved. It is also possible to reduce the moisture absorption rate after curing of the adhesive layer. Preferable inorganic fillers include powders such as silica, alumina, talc, calcium carbonate, titanium white, bengara, silicon carbide, boron nitride, beads formed by spheroidizing them, single crystal fibers, glass fibers, and the like. These can be used individually by 1 type or in mixture of 2 or more types. In the present invention, among these, the use of silica powder and alumina powder is preferable.

The usage-amount of an inorganic filler can be normally adjusted in 0-80 weight% of range with respect to the whole adhesive agent.
(Other ingredients)
In addition to the above, various additives may be blended in the adhesive composition of the present invention as necessary. For example, a flexible component can be added to maintain the flexibility after curing. The flexible component is a component having flexibility at normal temperature and under heating, and a component that is not substantially cured by heating or energy ray irradiation is selected. The flexible component may be a polymer made of a thermoplastic resin or an elastomer, or may be a polymer graft component or a polymer block component. Moreover, the modified resin by which the flexible component was previously modified | denatured by the epoxy resin may be sufficient.

Furthermore, as various additives for the adhesive composition, a plasticizer, an antistatic agent, an antioxidant, a pigment, a dye, or the like may be used.
(Adhesive composition)
The adhesive composition composed of each component as described above has pressure-sensitive adhesiveness and heat-curing property, and has a function of temporarily holding various adherends in an uncured state. Finally, a cured product with high impact resistance can be obtained through thermosetting, and the balance between shear strength and peel strength is excellent, and sufficient adhesive properties can be maintained even under severe heat and humidity conditions. .

  The adhesive composition according to the present invention can be obtained by mixing the above components at an appropriate ratio. In mixing, each component may be diluted with a solvent in advance, or a solvent may be added during mixing.

(Adhesive sheet)
The adhesive sheet according to the present invention is obtained by laminating an adhesive layer made of the above adhesive composition on a substrate. The adhesive sheet according to the present invention can have any shape such as a tape shape or a label shape.

  As the base material of the adhesive sheet, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, Polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film A transparent film such as a polyimide film is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient. In addition to the above-described transparent film, an opaque film colored with these can be used. However, when the adhesive composition of the present invention is cured with energy rays, the adhesive sheet of the present invention may be irradiated with energy rays such as ultraviolet rays from the substrate surface side when used. The substrate is preferably transparent to the energy rays used.

The adhesive sheet according to the present invention is affixed to various adherends, and after subjecting the adherend to the necessary processing, the adhesive layer remains adhered to the adherend and peels off from the substrate. Is done. That is, it is used for a process including a step of transferring an adhesive layer from a substrate to an adherend. For this reason, the surface tension of the surface in contact with the adhesive layer of the substrate is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. The lower limit is usually about 1 mN / m 2. Such a substrate having a low surface tension can be obtained by appropriately selecting the material, and can also be obtained by applying a release agent to the surface of the substrate and performing a release treatment.

  As the release agent used for the substrate release treatment, alkyd, silicone, fluorine, unsaturated polyester, polyolefin, wax, etc. are used, and in particular, alkyd, silicone, fluorine release agents. Is preferable because it has heat resistance.

In order to release the surface of the substrate using the above release agent, the release agent can be applied directly with a gravure coater, Mayer bar coater, air knife coater, roll coater, etc. without solvent, or by solvent dilution or emulsion. The laminate may be formed by normal temperature or heating or electron beam curing, wet lamination, dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing, or the like.

The film thickness of the substrate is usually about 10 to 500 μm, preferably about 15 to 300 μm, and particularly preferably about 20 to 250 μm.
Moreover, the thickness of an adhesive agent layer is 1-500 micrometers normally, Preferably it is 5-300 micrometers, Most preferably, it is about 10-150 micrometers.

  The method for producing the adhesive sheet is not particularly limited, and may be produced by applying and drying a composition constituting the adhesive layer on the substrate, and the adhesive layer is peeled off. You may manufacture by providing on a film and transferring this to the said base material. In addition, in order to protect an adhesive layer before using an adhesive sheet, you may laminate | stack a peeling film on the upper surface of an adhesive layer. As a method for applying the adhesive layer, a method using a known coating apparatus such as a roll coater, a knife coater, a roll knife coater, a die coater, or a curtain coater can be used.

  In addition, a jig such as a ring frame is used to fix the adhesive sheet and the wafer from the dicing process to the die bonding process. When the adhesive sheet is peeled off from the ring frame, one of the adhesive layers is used. In order to fix the adhesive sheet without remaining on the ring frame, another adhesive layer or an adhesive tape may be separately provided on the outer peripheral portion of the surface of the adhesive layer.

(Usage method of adhesive sheet)
Next, a method for using the adhesive sheet according to the present invention will be described by taking as an example the case where the adhesive sheet is applied to the manufacture of a semiconductor device, particularly a stacked semiconductor device.

A method for manufacturing a semiconductor device according to the present invention includes:
A semiconductor wafer is adhered to the adhesive layer of the adhesive sheet according to the present invention, the semiconductor wafer is diced into a semiconductor chip, and the adhesive layer is fixed and left on the back surface of the semiconductor chip. And the step of thermocompression bonding the semiconductor chip onto the substrate via the adhesive layer.

In addition, a method for manufacturing another semiconductor device (stacked semiconductor device) according to the present invention includes:
A semiconductor wafer is adhered to the adhesive layer of the adhesive sheet according to the present invention, the semiconductor wafer is diced into a semiconductor chip, and the adhesive layer is fixed and left on the back surface of the semiconductor chip. And the step of thermocompression bonding the semiconductor chip onto another semiconductor chip via the adhesive layer (hereinafter also referred to as “thermocompression step (a)”), and these semiconductor chips on the substrate The process of fixing to is included.

  In the method of manufacturing a semiconductor device (including a stack type semiconductor device) according to the present invention, first, the adhesive sheet according to the present invention is fixed on a dicing device by a ring frame, and one surface of the silicon wafer is fixed. It is placed on the adhesive layer of the adhesive sheet and lightly pressed to fix the wafer. Thereafter, when the adhesive composition contains the energy beam polymerizable compound (I), the adhesive layer is irradiated with energy rays from the substrate side to increase the cohesive strength of the adhesive layer. , Reducing the adhesive force between the adhesive layer and the substrate. As energy rays to be irradiated, ultraviolet rays (UV) or electron beams (EB) are used, and preferably ultraviolet rays are used.

  The energy beam irradiation may be performed at any stage after the semiconductor wafer is pasted and before the semiconductor chip is peeled off. For example, it may be performed after dicing, or may be performed after the following expanding step. Further, the energy beam irradiation may be performed in a plurality of times.

  Next, the silicon wafer is cut using a cutting means such as a dicing saw to obtain a semiconductor chip. The cutting depth at this time is set to a depth that takes into account the total thickness of the silicon wafer and the adhesive layer and the amount of wear of the dicing saw.

  Next, when the adhesive sheet is expanded as necessary, the interval between the semiconductor chips is expanded, and the semiconductor chips can be picked up more easily. At this time, a deviation occurs between the adhesive layer and the base material, the adhesive force between the adhesive layer and the base material is reduced, and the pick-up property of the chip is improved.

When the semiconductor chip is picked up in this way, the cut adhesive layer can be adhered to the back surface of the semiconductor chip and peeled off from the substrate.
Next, the semiconductor chip is placed on the substrate or on another semiconductor chip (hereinafter also referred to as “lower chip”) (usually on the surface side of the semiconductor chip) via the adhesive layer.

  The step of fixing the plurality of semiconductor chips on the substrate in the method of manufacturing a semiconductor device (stacked semiconductor device) according to the present invention may be before or after the thermocompression bonding step (a). Therefore, the semiconductor chip may be thermocompression-bonded on another semiconductor chip (lower chip) already stacked on the substrate via the adhesive layer made of the adhesive composition of the present invention. A semiconductor chip laminate was formed on the semiconductor chip by thermocompression bonding of the semiconductor chip via the adhesive layer comprising the adhesive composition of the present invention, and then the semiconductor chip laminate was placed on the substrate. It may be fixed. An example of the fixing means is thermocompression bonding.

  The lower chip may be a semiconductor chip that is directly laminated (or laminated) on the substrate via an adhesive layer or the like, and a plurality of laminated chips (or laminated) on the substrate. It may be the uppermost semiconductor chip (farthest from the substrate) of the semiconductor chip stack including the semiconductor chips.

  In addition, an adhesive layer or a cured product thereof is provided between the substrate and the lowermost chip or the semiconductor chip at the bottom of the semiconductor chip stack (closest to the substrate) and between the semiconductor chips in the semiconductor chip stack. These may be conventionally known ones, but as an adhesive layer interposed between semiconductor chips in a semiconductor chip laminate or a cured product thereof, the adhesive composition of the present invention is used. Or the hardened | cured material is preferable.

  When the semiconductor chip is placed on the lower chip surface, it may be placed so that the adhesive layer of the stacked chips does not contact the wire connected to the lower chip, and the thickness of the adhesive layer If the wire is thicker than the height of the wire connected to the lower chip, the wire may be embedded. The mounting body is heated before or immediately after mounting the semiconductor chip. The heating temperature is usually 80 to 200 ° C., preferably 100 to 180 ° C., the heating time is usually 0.1 seconds to 5 minutes, preferably 0.5 seconds to 3 minutes, and the chip mount pressure is Usually, it is 1 kPa to 200 MPa.

  After the semiconductor chip is placed on the substrate or the surface of the lower chip, further heating may be performed as necessary. The heating conditions at this time are in the above heating temperature range, and the heating time is usually 1 to 180 minutes, preferably 10 to 120 minutes.

  Further, the adhesive layer may be cured by using the heat in the resin sealing performed in a subsequent process, without performing the heat treatment after the chip mounting. Furthermore, when the semiconductor device has a plurality of adhesive layers, these adhesives may be thermoset every time one layer is provided, or may be thermoset all at once after providing all layers. Good.

  Through such steps, the adhesive layer is cured, and the semiconductor chip can be firmly bonded to the substrate or another semiconductor chip. Since the adhesive layer is fluidized under die-bonding conditions, even if there are slight irregularities derived from the circuit pattern on the substrate surface or the lower chip surface, the adhesive layer is sufficiently embedded, and generation of voids can be prevented.

  In other words, in the obtained mounting product, the adhesive, which is a means for fixing the chip, is cured and sufficiently embedded in the unevenness of the adherend, so that a sufficient package can be obtained even under severe conditions. Reliability is achieved.

  In addition, the adhesive composition and adhesive sheet of this invention can be used for adhesion | attachment of a semiconductor compound, glass, ceramics, a metal other than the above usage methods.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Each component which comprises the adhesive composition of each Example and a comparative example was as follows.
(A) Acrylic polymer: Coponil N-2359-6 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
(B) Phenol resin having an unsaturated hydrocarbon group (B-1) Novolac-type unsaturated group-containing phenol resin (HRM-1005, molecular weight 2000, phenolic hydroxyl group equivalent 215 g / eq, Showa Polymer Co., Ltd.)
(B-2) Novolac type unsaturated group-containing phenol resin (HRM-1004, Showa Polymer Co., Ltd., molecular weight 4000, phenolic hydroxyl group equivalent 215 g / eq)
(C) Liquid epoxy resin: bisphenol A type epoxy resin (Epicoat 828, epoxy equivalent 189 g / eq, manufactured by Japan Epoxy Resin Co., Ltd.)
(D) Thermosetting agent: Thermosetting agent novolac type phenolic resin (Showa Polymer Co., Ltd .: Shonor BRG-556, phenolic hydroxyl group equivalent 104 g / eq)
(E) Ion scavenger (E-1): IXE633 (mixture of antimony pentoxide and bismuth oxide) manufactured by Toagosei Co., Ltd.
(E-2): DHT-4A (hydrotalcite) manufactured by Kyowa Chemical Industry Co., Ltd.
(E-3): Kyowa Chemical Industry Co., Ltd. KW2200 (baked product of hydrotalcite)
(F) Curing accelerator: Imidazole (Curesol 2PHZ manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(G) Silane coupling agent (MKC silicate MSEP2 manufactured by Mitsubishi Chemical Corporation)
(H) Crosslinker: Aromatic polyisocyanate (Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.)
(I) Energy ray polymerizable compound: Dipentaerythritol hexaacrylate (Kayarad DPHA manufactured by Nippon Kayaku Co., Ltd.)
(J) Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.)
(K) Inorganic filler: Silica (Admafine SC2050 manufactured by Admatechs Co., Ltd.)
Further, a polyethylene film (thickness: 100 μm, surface tension: 33 mN / m) was used as the base material of the adhesive sheet.

(Examples, comparative examples and reference examples)
The adhesive composition having the composition described in Table 1 was used. In the table, the numerical values indicate parts by weight in terms of solid content (non-volatile content). The adhesive composition having the composition shown in Table 1 was applied on a silicone-treated release film (SP-PET381031 (S) manufactured by Lintec Corporation) so that the film thickness after drying was 60 μm and dried. (Drying conditions: 100 ° C in oven for 1 minute)
An adhesive sheet was prepared by transferring the adhesive layer to a substrate.

  The adhesive sheet thus obtained was measured for impurity ion concentration, electrical conductivity, and shear adhesive strength after wet heat, and surface mountability evaluation was performed on a semiconductor device manufactured using these adhesive sheets ( Reflow resistance) and HAST (HAST resistance) were performed. The results are shown in Table 2.

  Details of the semiconductor device manufacturing method and evaluation method will be described later.

<Evaluation of surface mountability>
(Manufacture of semiconductor devices for surface mountability evaluation)
(1) Manufacture of semiconductor chips;
# 2000 polished silicon wafer (150mm diameter, 150μm thick) Affixing the adhesive sheets of Examples and Comparative Examples to a tape mounter (Adwill RAD2500, Lintec Co., Ltd.) and wafer dicing ring frame Fixed to. Thereafter, the substrate was irradiated with ultraviolet rays (350 mW / cm ² , 190 mJ / cm ² ) using an ultraviolet irradiation device (Adwill RAD2000, manufactured by Lintec Corporation).

  Next, dicing was performed using a dicing apparatus (Tokyo Seimitsu Co., Ltd., AWD-4000B) to produce an 8 mm × 8 mm size chip. With respect to the cutting amount at the time of dicing, the substrate was cut by 20 μm.

(2) Manufacturing of semiconductor packages;
A circuit board is formed on the copper foil of a copper foil-clad laminate (CCL-HL830 manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a substrate, and a solder resist (PSR4000 AUS5 made by Taiyo Ink) is 40 μm thick on the pattern. (Made by Chino Giken Co., Ltd.). The chip (first stage chip) on the adhesive sheet obtained in (1) above is picked up from the base material together with the adhesive layer, and is placed on the BT substrate at 100 ° C., 300 gf, via the adhesive layer. The pressure-bonding was carried out under conditions of 1 second, and then heated at 120 ° C. for 1 hour and further at 140 ° C. for 1 hour to sufficiently heat-cure the adhesive layer.

A chip with an adhesive layer (second-stage chip) of the same size as the first-stage chip is pressure-bonded on this mounted first-stage chip under the conditions of 100 ° C, 100gf, 1 second, and then 120 ° C. In 1 hour,
Furthermore, it heated at 140 degreeC for 1 hour, and fully hardened the adhesive layer of the 2nd step | tip chip.

Then, the BT substrate is sealed with a molding resin (KE-1100AS3 manufactured by Kyocera Chemical Co., Ltd.) so that the sealing thickness is 700 μm (sealing device: MPC-06M Trial Press manufactured by Apic Yamada Co., Ltd.), and at 175 ° C. for 5 hours. The mold resin was cured. Next, the sealed BT substrate is attached to a dicing tape (Adwill D-510T manufactured by Lintec Corporation), and a dicing apparatus (
A semiconductor package for reliability evaluation was created by dicing into 12mm x 12mm size using Tokyo Seimitsu Co., Ltd. (AWD-4000B).

<HAST>
(Manufacture of HAST semiconductor devices)
(3) Manufacture of semiconductor chips;
Attaching the adhesive sheets of Examples and Comparative Examples to the polished surface (dry polished surface) of a TEG wafer (150 mm diameter, 80 μm thickness, aluminum pad) that has been dry-polished and can be electrically evaluated This was performed by a mounter (Adwill RAD2500, manufactured by Lintec Corporation) and fixed to a ring frame for wafer dicing. Thereafter, the substrate was irradiated with ultraviolet rays (350 mW / cm ² , 190 mJ / cm ² ) using an ultraviolet irradiation device (Adwill RAD2000, manufactured by Lintec Corporation).

Next, dicing was performed using a dicing apparatus (manufactured by Tokyo Seimitsu Co., Ltd., AWD-4000B) to produce a chip of 8 mm × 8 mm size having an adhesive layer on the dry polish surface side. With respect to the cutting amount at the time of dicing, the substrate was cut by 20 μm.

(4) Manufacturing of semiconductor packages;
A circuit board is formed on the copper foil of a copper foil-clad laminate (CCL-HL830 manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a substrate, and a solder resist (PSR4000 AUS5 made by Taiyo Ink) is 40 μm thick on the pattern. (Made by Chino Giken Co., Ltd.). The chip (first-stage chip) on the adhesive sheet obtained in (3) above is picked up from the base material together with the adhesive layer, and is placed on the BT substrate at 100 ° C., 300 gf, via the adhesive layer. The pressure-bonding was carried out under conditions of 1 second, and then heated at 120 ° C. for 1 hour and further at 140 ° C. for 1 hour to sufficiently heat-cure the adhesive layer.

Next, wire bonding was performed between the pad on the upper surface of the first-stage chip and the substrate pad to enable electrical connection. Furthermore, a chip with an adhesive layer (second-stage chip) of the same size as the first-stage chip is pressure-bonded on the first-stage chip after wire bonding under the conditions of 100 ° C, 100gf, 1 second, and then The adhesive layer of the second-stage chip was sufficiently cured by heating at 120 ° C. for 1 hour and further at 140 ° C. for 1 hour.

Then, the BT substrate is sealed with a molding resin (KE-1100AS3 manufactured by Kyocera Chemical Co., Ltd.) so that the sealing thickness is 700 μm (sealing device: MPC-06M Trial Press manufactured by Apic Yamada Co., Ltd.), and at 175 ° C. for 5 hours. The mold resin was cured. Next, solder balls are mounted on the external electrode pads on the backside of the board, and the HAS is 15mm x 15mm x 0.4mm thick and 108 external electrodes (27 x 4 sides)
A semiconductor device (package) for T was created.

<Evaluation method>
(A) impurity ion concentration and electrical conductivity;
The adhesive layers of the adhesive sheet were laminated at room temperature until the total thickness was 200 μm. The obtained laminate was irradiated with ultraviolet rays from both sides (illuminance 350 mW / cm ² , light intensity 190 mJ / cm ² ), and then this laminate was heated in an oven at 120 ° C. for 30 minutes and further at 140 ° C. for 30 minutes. A cured adhesive was obtained.

The resulting cured adhesive is pulverized using a pulverizer (vibration pulverizer TI-100, manufactured by Heiko Seisakusho Co., Ltd.), sieved with a 100 mesh stainless steel wire mesh, and Teflon (registered trademark) for ion concentration measurement. ) 1 g of the wire mesh passed through the made container was mixed with 20 ml of pure water and heated at 121 ° C. for 24 hours to prepare an extract.

The ion concentration of the obtained extract was measured by ion chromatography (DX-320 manufactured by Nippon Dionex Co., Ltd.), and the electrical conductivity was measured by a conductivity meter (B-173 manufactured by Horiba, Ltd.).

(B) shear bond strength;
The adhesive sheets of Examples and Comparative Examples were attached to the surface of the 350 μm-thick silicon wafer subjected to CMP treatment using a tape mounter (Adwill RAD2500, manufactured by Lintec Corporation), and fixed to the ring frame for wafer dicing. Thereafter, the substrate was irradiated with ultraviolet rays (350 mW / cm ² , 190 mJ / cm ² ) using an ultraviolet irradiation device (Adwill RAD2000, manufactured by Lintec Corporation).

Subsequently, dicing was performed using a dicing apparatus (manufactured by Tokyo Seimitsu Co., Ltd., AWD-4000B) to produce a 5 mm × 5 mm size chip with an adhesive layer. With respect to the cutting amount at the time of dicing, the substrate was cut by 20 μm.

  In addition, a 725μm thick wafer coated with 3μm thick polyimide resin (PLH708 made by Hitachi Chemical DuPont Microsystems Co., Ltd.) as a protective layer on one side is diced to 12mm x 12mm size, and an adhesive layer A chip without was created.

The chip with the adhesive layer is pressure-bonded to the polyimide resin surface of the chip without the adhesive layer under the conditions of 100 ° C, 100gf, 1 second, and these are baked at 120 ° C for 30 minutes in the oven. 140 ℃
The adhesive layer was cured by heating for 30 minutes to obtain a test piece (i). Further, a part of the plurality of test pieces (i) was put into a constant temperature bath at 85 ° C. and 60% RH for 48 hours and then taken out to obtain a test piece (ii).

  With respect to the test pieces (i) and (ii) thus obtained, the hot-bond strength in the shear direction of a 5 mm × 5 mm size chip was measured using a push-pull gauge. The hot bond strength was measured on a 250 ° C. heat block.

(C) Evaluation of surface mountability (reflow resistance);
A semiconductor device created for surface mountability evaluation is left at 85 ° C, 60% RH for 168 hours to absorb moisture, and then IR reflow with a maximum temperature of 260 ° C and a total heating time of 3 minutes (Reflow oven: manufactured by Sagami Riko) WL-15-20DNX type) 3 times to check whether the joints in the semiconductor device are lifted or peeled off, and whether there are package cracks. Scanning ultrasonic flaw detector (Hye-Focus manufactured by Hitachi Construction Machinery Finetech Co., Ltd.) Evaluation was made by cross-sectional observation.

The case where peeling was observed with an area of 0.25 mm ² or more at the substrate / semiconductor chip junction or chip / chip junction was judged as peeling. The evaluation was performed for 25 semiconductor devices, and the number of peeling occurred was counted.

(D) HAST (HAST resistance);
After mounting the HAST semiconductor device on the secondary substrate for electrode lead-out, leave it as a pre-treatment for 60 hours at 60 ° C and 60% RH, then at 130 ° C, 85% RH, 220 hours, with an applied voltage of 3.5V The device was always energized under the conditions.

Evaluation was performed for 20 semiconductor devices, and the number of defects was counted. A sample having an insulation resistance value between the electrodes lower than 1 × 10 ⁷ Ω was judged as defective.

  According to the present invention, a package mounted with a thinning semiconductor chip has high package reliability even when exposed to severe reflow conditions or when a voltage is applied under high temperature and high humidity. And an adhesive sheet having an adhesive layer comprising the adhesive composition, and an adhesive sheet comprising the adhesive composition, which can improve long-term physical and electrical bonding reliability A semiconductor device (particularly, a stack type semiconductor device) using this adhesive sheet and a method for manufacturing the same are provided.

Claims (6)

An acrylic polymer, a compound (B) having a functional group capable of reacting with an epoxy group and an unsaturated hydrocarbon group in one molecule, an epoxy thermosetting resin, and an ion scavenger , wherein the compound (B) is Selected from the group consisting of a compound in which part of the hydroxyl group of the phenol resin is substituted with a group containing an unsaturated hydrocarbon group, and a compound in which a group containing an unsaturated hydrocarbon group is directly bonded to the aromatic ring of the phenol resin. Adhesive composition.   The pressure-sensitive adhesive composition according to claim 1, wherein the content of the ion scavenger is 1 to 15 parts by weight with respect to 100 parts by weight of the total resin components.   The adhesive composition according to claim 1 or 2, wherein the phenol resin is a novolac type phenol resin. An adhesive sheet in which an adhesive layer made of the adhesive composition according to claim 1 is formed on a substrate. A semiconductor wafer is attached to the adhesive layer of the adhesive sheet according to claim 4 , the semiconductor wafer is diced into a semiconductor chip, and the adhesive layer is fixed and left on the back surface of the semiconductor chip. A method for manufacturing a semiconductor device, comprising a step of peeling from a base material and thermocompression bonding the semiconductor chip onto a substrate via the adhesive layer. A semiconductor wafer is attached to the adhesive layer of the adhesive sheet according to claim 4 , the semiconductor wafer is diced into a semiconductor chip, and the adhesive layer is fixed and left on the back surface of the semiconductor chip. A method of manufacturing a semiconductor device, comprising: a step of peeling from a base material, and thermocompression bonding the semiconductor chip onto another semiconductor chip via the adhesive layer; and a step of fixing these semiconductor chips on a substrate.