KR20200125956A - Semiconductor adhesive and method of manufacturing semiconductor device using same - Google Patents

Abstract

The present invention is a semiconductor device in which electrodes of respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which electrodes of respective connection portions of a plurality of semiconductor chips are electrically connected to each other, As an adhesive for semiconductors used for sealing at least a portion of, the thixotropy value of the semiconductor adhesive is 1.0 or more and 3.1 or less, and the thixotropy value is the shear viscosity of the sample obtained by laminating the semiconductor adhesive to a thickness of 400 μm. The device measures the viscosity when the frequency is continuously changed from 1 Hz to 70 Hz under constant conditions of 120°C, and provides an adhesive for semiconductors, which is the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz. .

Description

Semiconductor adhesive and method of manufacturing semiconductor device using same

The present disclosure relates to an adhesive for semiconductors and a method of manufacturing a semiconductor device using the same.

Conventionally, in order to connect a semiconductor chip and a substrate, a wire bonding method using a fine metal wire such as a gold wire has been widely applied. On the other hand, in order to meet the demands of higher functionality, higher integration, and higher speed for semiconductor devices, a flip chip connection method (FC connection method) in which conductive protrusions called bumps are formed on a semiconductor chip or substrate and are directly connected between the semiconductor chip and the substrate. Is expanding.

As a flip chip connection method, a method of bonding metal using solder, tin, gold, silver, copper, etc., a method of bonding metal by applying ultrasonic vibration, a method of maintaining mechanical contact by the contraction force of a resin, etc. are known. From the viewpoint of reliability of the connection portion, a method of bonding metal using solder, tin, gold, silver, copper, or the like is common.

For example, in connection between a semiconductor chip and a substrate, a COB (Chip On Board) type connection method that is frequently used for BGA (Ball Grid Array), CSP (Chip Size Package), etc. is also a flip chip connection method. In addition, the flip chip connection method is also widely used in a COC (Chip On Chip) type connection method in which a connection part (bump or wiring) is formed on a semiconductor chip to connect between semiconductor chips (for example, see Patent Document 1 below. ).

In packages where further miniaturization, thinness, and high functionality are strongly required, chip-stack type packages, POP (Package On Package), TSV (Through-Silicon Via), etc. which are stacked and multi-stage of the above-described connection method are also starting to be widely spread . Since the package can be reduced by placing it in a three-dimensional shape rather than a flat type, these technologies are widely used and are effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, and are attracting attention as a next-generation semiconductor wiring technology. .

Patent Document 1: Japanese Patent Laid-Open No. 2016-102165

In a flip chip package that is progressing with higher functionality, higher integration, and lower cost, for high productivity, it is required to suppress the width of resin protrusion during chip mounting and to mount the chip at high density. For this reason, if the load of compression bonding is lightened, the width of the resin protrusion is suppressed, but there is a risk that the edge portion of the chip becomes insufficient in resin, leading to chip peeling or the like.

The present disclosure is a semiconductor adhesive and a semiconductor device using the same, which can obtain a semiconductor device without lack of resin during mounting by controlling the shape of the resin protruding during chip mounting and protruding the resin in a shape along the side of the chip. Its main purpose is to provide a method of manufacturing.

One aspect of the present disclosure is, [1] a semiconductor device in which electrodes of respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or electrodes of respective connection portions of a plurality of semiconductor chips are electrically connected to each other. In a semiconductor device, a semiconductor adhesive used for sealing at least a portion of the connection portion, wherein the semiconductor adhesive has a thixotropy value of 1.0 or more and 3.1 or less, and the thixotropy value is the semiconductor adhesive with a thickness of 400 μm For the samples stacked up to, the viscosity at the time of continuously changing the frequency from 1 Hz to 70 Hz under a constant condition of 120°C with a shear viscosity measuring device, and the viscosity value at 7 Hz is the viscosity at 70 Hz. It is an adhesive for semiconductors, divided by the value.

In addition, another aspect of the present disclosure is the adhesive for semiconductors according to [1], which contains [2] (a) an epoxy resin, (b) a curing agent, and (c) a high molecular weight component having a weight average molecular weight of 10000 or more.

In addition, another aspect of the present disclosure is the adhesive for semiconductors according to [2], further containing [3] (d) a filler.

In addition, another aspect of the present disclosure is the adhesive for semiconductors according to [2] or [3], further containing [4] (e) a flux agent.

In addition, another aspect of the present disclosure is [5] for the semiconductor according to any one of [2] to [4] above, wherein the (c) polydispersity Mw/Mn of the high molecular weight component with a weight average molecular weight of 10000 or more is 3 or less. It is an adhesive.

Further, another aspect of the present disclosure is [6] the adhesive for semiconductors according to any one of [2] to [5], wherein a part or all of the material contained in the semiconductor adhesive is soluble in cyclohexanone.

In addition, another aspect of the present disclosure is the adhesive for semiconductors according to any one of [1] to [6], which is a film type [7].

In addition, another aspect of the present disclosure is, by using the semiconductor adhesive according to any one of [8] to [1] to [7], the position of the semiconductor chip and the wiring circuit board through the semiconductor adhesive by a connection device A step of performing alignment and connecting to each other, electrically connecting electrodes of each connection portion of a semiconductor chip and a wiring circuit board to each other, and sealing at least a part of the connection portion with the semiconductor adhesive, or for the semiconductor by a connection device A step of aligning a plurality of semiconductor chips through an adhesive, connecting them to each other, electrically connecting electrodes of each connection portion of the plurality of semiconductor chips to each other, and sealing at least a part of the connection portion with the semiconductor adhesive This is a method of manufacturing a semiconductor device.

According to the present disclosure, by controlling the thixotropy value of the semiconductor adhesive, the shape of the resin protruding to the outer circumference of the chip when the semiconductor device is mounted is controlled, and resin shortage can be suppressed by protruding the resin in a shape along the side of the chip. I can. Further, according to the present disclosure, it is possible to provide a semiconductor device and a method of manufacturing the same using such an adhesive for semiconductors.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device according to the present disclosure.
2 is a schematic cross-sectional view showing another embodiment of the semiconductor device according to the present disclosure.
3 is a schematic cross-sectional view showing another embodiment of the semiconductor device according to the present disclosure.
4 is a schematic cross-sectional view showing another embodiment of the semiconductor device according to the present disclosure.

Hereinafter, in some cases, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. Meanwhile, in the drawings, the same or corresponding parts are denoted by the same reference numerals, and duplicate descriptions are omitted. In addition, the positional relationship, such as top, bottom, left and right, shall be based on the positional relationship shown in a figure, unless otherwise noted. In addition, the dimensional ratio of the drawings is not limited to the illustrated ratio.

In the present specification, the numerical range indicated by using "-" represents a range including the numerical values described before and after "-" as a minimum value and a maximum value, respectively. In the numerical range described step by step in the present specification, the upper or lower limit of the numerical range of a certain step can be arbitrarily combined with the upper or lower limit of the numerical range of another step. In the numerical range described in the present specification, the upper limit or lower limit of the numerical range may be substituted with a value shown in Examples. "A or B" should just include either of A and B, and both may be included. Materials illustrated in the present specification can be used alone or in combination of two or more, unless otherwise specified. In this specification, "(meth)acryl" means acrylic or methacryl corresponding to it.

<Semiconductor adhesive>

In the semiconductor adhesive according to the present embodiment, a semiconductor device in which electrodes of respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or electrodes of respective connection portions of a plurality of semiconductor chips are electrically connected to each other. In a semiconductor device, it is used for sealing at least a part of the connection portion.

The adhesive for semiconductors according to the present embodiment has a thixotropic value of 1.0 or more and 3.1 or less. The thixotropy value is obtained by measuring the viscosity of a sample in which the semiconductor adhesive is laminated to a thickness of 400 μm, when the frequency is continuously changed from 1 Hz to 70 Hz under a constant condition of a temperature of 120°C with a shear viscosity measuring device. , It is a value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz. If the thixotropy value is less than 3.1, the semiconductor adhesive can sufficiently flow even at the edge of the chip where the shear applied during chip mounting is the smallest, so that the resin protrudes in a shape along the side of the chip. On the other hand, the thixotropy value may be 1.5 or more, 2.0 or more, or 2.5 or more.

The adhesive for semiconductors according to the present embodiment may contain (a) an epoxy resin, (b) a curing agent, (c) a high molecular weight component having a weight average molecular weight of 10000 or more, and further contains (d) a filler and (e) a flux agent. It is desirable to do it

((a) component: epoxy resin)

Examples of the epoxy resin of the component (a) include epoxy resins having two or more epoxy groups in the molecule, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, cresolno Rock-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, triphenylmethane-type epoxy resins, dicyclopentadiene-type epoxy resins, and various multifunctional epoxy resins can be used. The component (a) can be used alone or in combination of two or more.

The content of the component (a) is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and still more preferably 20 to 40% by mass, based on the total solid content of the semiconductor adhesive. When the content of the component (a) is 10% by mass or more, it is easy to sufficiently control the flow of the resin after curing, and when it is 50% by mass or less, the resin component of the cured product does not become too large, and it is easy to reduce the warpage of the package. Further, by making the content of the component (a) within the above range, it is easy to control the thixotropy value of the semiconductor adhesive to 1.0 or more and 3.1 or less. The smaller the resin component and the larger the filler content is, the easier the thixotropy value is to be small. Therefore, it becomes easy to lower the thixotropy value by making the content of the component (a) 50% by mass or less.

((b) component: curing agent)

The adhesive for semiconductors according to the present embodiment contains (b) a curing agent. Examples of the curing agent 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, it is easy to exhibit a flux activity that suppresses the formation of an oxide film at the connection, and connection reliability and insulation reliability can be easily improved. Hereinafter, each curing agent will be described.

(b-i) phenol resin curing agent

Examples of the phenol resin-based curing agent include curing agents having two or more phenolic hydroxyl groups in the molecule, and phenol novolac resins, cresol novolac resins, phenol aralkyl resins, cresol naphthol formaldehyde polycondensates, triphenylmethane type polyfunctional phenols Resins, various polyfunctional phenolic resins, etc. can be used. The phenol resin curing agent can be used alone or in combination of two or more.

The equivalent ratio (phenolic hydroxyl group/epoxy group, molar ratio) of the phenolic resin-based curing agent to the component (a) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, from the viewpoint of excellent curability, adhesiveness and storage stability, 0.5 to 1.0 are more preferable. If the equivalence ratio is 0.3 or more, the curability tends to be improved and adhesion is improved, and if it is 1.5 or less, the unreacted phenolic hydroxyl group does not remain excessive, the water absorption rate is suppressed to be low, and the insulation reliability tends to be further improved. There is this.

(b-ii) acid anhydride curing agent

As the acid anhydride-based curing agent, methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, ethylene glycolbisanhydrotrimelitate, and the like can be used. The acid anhydride-based curing agent can be used alone or in combination of two or more.

The equivalent ratio (acid anhydride group/epoxy group, molar ratio) of the acid anhydride-based curing agent to the component (a) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, from the viewpoint of excellent curability, adhesion and storage stability. , 0.5 to 1.0 are more preferable. When the equivalence ratio is 0.3 or more, the curability tends to be improved and the adhesive strength is improved, and when it is 1.5 or less, the unreacted acid anhydride does not remain excessively, the water absorption rate is suppressed to be low, and the insulation reliability tends to be further improved. have.

(b-iii) amine curing agent

As the amine-based curing agent, dicyandiamide, various amine compounds, and the like can be used.

The equivalent ratio (amine/epoxy group, molar ratio) of the amine-based curing agent to the component (a) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and 0.5 to 1.0 from the viewpoint of excellent curability, adhesion and storage stability. This is more preferable. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength is improved. When the equivalent ratio is 1.5 or less, the unreacted amine does not remain excessively, and the insulation reliability tends to be further improved.

(b-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-cyano Ethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimida Zolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-one Silimidazolyl-(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-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct , 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of an epoxy resin and imidazoles. Among these, from the viewpoint of further excellent curability, storage stability and connection reliability, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2- Undecylimidazole 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-triazineisocyanulic acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxy Methylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole are preferred. The imidazole-based curing agent can be used alone or in combination of two or more. Further, these may be microencapsulated latent curing agents.

The content of the imidazole-based curing agent is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the component (a). If the content of the imidazole-based curing agent is 0.1 parts by mass or more, curability tends to be improved, and if it is 20 parts by mass or less, the adhesive composition does not cure before the metal bonding is formed, and connection failure tends to be difficult to occur. have.

(b-v) phosphine-based curing agent

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

The content of the phosphine curing agent is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the component (a). 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 semiconductor adhesive does not harden before the metal bonding is formed, and connection failure tends to be difficult to occur. have.

The phenol resin-based curing agent, the acid anhydride-based curing agent, and the amine-based curing agent may be used alone or in combination of two or more. The imidazole-based curing agent and the phosphine-based curing agent may be used individually, but may be used together with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

(b) As a component, from the viewpoint of excellent curability, a combination of a phenol resin curing agent and an imidazole curing agent, an acid anhydride curing agent and an imidazole curing agent are used in combination, an amine curing agent and an imidazole curing agent are used in combination, an imidazole curing agent It is preferably used alone. Since productivity is improved when connected in a short time, it is more preferable to use an imidazole-based curing agent alone, which is excellent in fast curing properties. In this case, since volatile components such as low molecular weight components can be suppressed by curing in a short time, generation of voids can also be easily suppressed.

((c) component: a high molecular weight component with a weight average molecular weight of 10000 or more)

(c) As a high molecular weight component with a weight average molecular weight of 10000 or more (excluding the compound corresponding to the component (a)), a phenoxy resin, a polyimide resin, a polyamide resin, a polycarbodiimide resin, a cyanate ester resin, ( Meth)acrylic resins, polyester resins, polyethylene resins, polyethersulfone resins, polyetherimide resins, polyvinyl acetal resins, polyurethane resins, acrylic rubbers, etc., among them, the viewpoint of excellent heat resistance and film formation properties In this, phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber, cyanate ester resin, and polycarbodiimide resin are preferred, and phenoxy resin, polyimide resin, (meth)acrylic resin, and acrylic rubber are preferred. More preferable. The component (c) may be used alone or as a mixture or copolymer of two or more.

The mass ratio of the component (c) and the component (a) is not particularly limited, but in order to maintain the film form, the content of the component (a) is preferably 0.01 to 5 parts by mass per 1 part by mass of the component (c). And, it is more preferable that it is 0.05-4 mass parts, and it is still more preferable that it is 0.1-3 mass parts. When the content of the component (a) is 0.01 parts by mass or more, the curability does not decrease or the adhesive strength is decreased, and when the content is 5 parts by mass or less, the film formability and the film formability do not decrease. In addition, the thixotropic value can be adjusted also by the combination of the component (c) and the component (a), and the mass ratio thereof.

The weight average molecular weight of the component (c) is 10000 or more in terms of polystyrene, but in order to show satisfactory film formation by itself, 30000 or more is preferable, 40000 or more is more preferable, and 50000 or more is still more preferable. When the weight average molecular weight is 10000 or more, there is no fear of deteriorating film formation. In addition, in this specification, the weight average molecular weight means the weight average molecular weight when it measured by polystyrene conversion using high-performance liquid chromatography (C-R4A manufactured by Shimadzu Corporation).

The polydispersity Mw/Mn of the component (c) is preferably 3 or less, and more preferably 2.5 or less. When Mw/Mn is 3 or less, it is thought that there is a tendency that there is little variation in molecular weight and the thixotropic value tends to be low.

((d) ingredient: filler)

As a filler of the component (d), an insulating inorganic filler, etc. are mentioned. Especially, it is more preferable if it is an inorganic filler with an average particle diameter of 100 nm or less. Examples of the insulating inorganic filler include glass, silica, alumina, titanium oxide, mica, boron nitride, and the like. Among them, silica, alumina, titanium oxide, boron nitride are preferable, and silica, alumina, boron nitride are more preferable. . The insulating inorganic filler may be a whisker, and examples of the whisker include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride. The insulating inorganic fillers can be used alone or in combination of two or more. The shape, particle diameter, and content of the component (d) are not particularly limited.

From the viewpoint of further excellent insulation reliability, it is preferable that the component (d) is insulating. It is preferable that the adhesive for semiconductors according to the present embodiment does not contain a conductive metal filler such as a silver filler or a solder filler.

The component (d) is preferably a filler subjected to a surface treatment from the viewpoint of improving dispersibility and adhesion. As the surface treatment agent, a glycidyl-based (epoxy) compound (excluding the compound corresponding to the component (a)), an amine-based compound, a phenyl-based compound, a phenylamino-based compound, a (meth)acrylic compound (e.g., the following general formula (A compound having a structure represented by (1)), a vinyl compound having a structure represented by the following general formula (2), and the like.

[In the formula, R ¹¹ represents a hydrogen atom or an alkyl group, and R ¹² represents an alkylene group.]

As the surface-treated filler by a compound having a structure represented by the general formula (1), wherein R ¹¹ is a hydrogen atom acrylic surface treated filler, R ¹¹ is a methyl group of methacrylic surface-treated filler, R ¹¹ is ethacrylic surface is an ethyl group Treatment fillers, etc., from the viewpoint of reactivity with the surface of the resin and the semiconductor substrate contained in the semiconductor adhesive, and from the viewpoint of formation of bonds, R ¹¹ is not bulky, an acrylic surface treatment filler and a methacrylic surface treatment filler desirable. R ^{12 is} also not particularly limited, but the higher the weight average molecular weight is, the lower the volatile component is, so it is preferable.

[In the formula, R ²¹ , R ²² and R ²³ represent a monovalent organic group, and R ²⁴ represents an alkylene group.]

For example, from the viewpoint of not lowering the reactivity, R ²¹ , R ^22, and R ²³ are preferably groups of relatively low volume, and may be, for example, a hydrogen atom or an alkyl group. Further, R ²¹ , R ²² and R ²³ may be monovalent organic groups in which the reactivity of the vinyl group is improved. R ^{24 is} also not particularly limited, but since it is difficult to volatilize, it is preferable that the weight average molecular weight is higher from the viewpoint of easily reducing voids. In addition, R ²¹ , R ²² , R ²³ and R ²⁴ may be selected due to the ease of surface treatment.

As the surface treatment agent, since the surface treatment is easy, silane treatment agents such as epoxy-based silane, amino-based silane, and (meth)acrylic-based silane are preferable. As the surface treatment agent, glycidyl-based, phenylamino-based, and (meth)acrylic-based compounds are preferable from the viewpoints of excellent dispersibility, fluidity, and adhesion. As the surface treatment agent, a phenyl-based or (meth)acrylic-based compound is more preferable from the viewpoint of excellent storage stability.

The average particle diameter of the component (d) is preferably 100 nm or less, and more preferably 60 nm or less from the viewpoint of improving visibility. The component (d) is preferably an inorganic filler having an average particle diameter of 60 nm or less, surface-treated with (meth)acrylic silane or epoxy silane from the viewpoint of improving adhesion. On the other hand, as for the thixotropy value, the larger the average particle diameter of the component (d) tends to decrease.

The content of the component (d) is preferably 20 to 80 mass%, more preferably 30 to 75 mass%, and even more preferably 50 to 75 mass% based on the total amount of the semiconductor adhesive. When the content of the component (d) is 20% by mass or more, there is no fear that the adhesive strength is lowered or the reflow resistance is lowered. In addition, when the content of the component (d) is 40% by mass or less, there is no fear that the connection reliability is deteriorated due to thickening. The higher the content of the component (d), the smaller the thixotropic value tends to be.

((e) component: flux agent)

The semiconductor adhesive may further contain a flux agent (e) exhibiting flux activity (activity to remove oxides, impurities, etc.). Examples of the flux agent include nitrogen-containing compounds (imidazoles, amines, etc., except those contained in component (b)), carboxylic acids, phenols, and alcohols having a non-shared electron pair. On the other hand, compared to alcohols, carboxylic acids exhibit a strong flux activity, and the connectivity is easy to improve.

The content of the component (e) is preferably 0.2 to 3 mass%, more preferably 0.4 to 1.8 mass%, based on the total solid content of the semiconductor adhesive from the viewpoint of solder wettability.

The semiconductor adhesive may further contain an ion trapper, an antioxidant, a silane coupling agent, a titanium coupling agent, a leveling agent, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types. The amount of these additives may be appropriately adjusted so that the effect of each additive is expressed.

<Method of manufacturing adhesive for semiconductors>

From the viewpoint of improving productivity, the adhesive for semiconductors according to the present embodiment is preferably a film type (film adhesive). The manufacturing method of the film adhesive is demonstrated below.

First, a component (a), component (b), component (c), and, if necessary, other components are added to an organic solvent, and then dissolved or dispersed by stirring, mixing, kneading, or the like to prepare a resin varnish. Thereafter, on the base film subjected to the release treatment, a resin varnish is applied using a knife coater, roll coater, applicator, die coater, comma coater, etc., and then the organic solvent is reduced by heating to form a film on the base film. Mold adhesive to form. In addition, before reducing the organic solvent by heating, a film-type adhesive may be formed on the wafer by spin coating a resin varnish on a wafer or the like to form a film, followed by solvent drying.

As the organic solvent used in the preparation of the resin varnish, it is preferable that each component has the property of uniformly dissolving or dispersing, such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide , Diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. have. Among these, it is preferable to use cyclohexanone from the viewpoint of film-forming properties, and it is preferable that some or all of the materials contained in the semiconductor adhesive are soluble in cyclohexanone. That is, it is preferable that a part or all of the material contained in the resin varnish is a cyclohexanone melt. These organic solvents can be used alone or in combination of two or more. Stirring mixing and kneading at the time of preparing the resin varnish can be performed using, for example, a stirrer, a thunderbolt, three rolls, a ball mill, a beads 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 polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, polyether Naphthalate film, methylpentene film, etc. are mentioned. The base film is not limited to a single layer including one of these films, and a multilayer film including two or more films may be used.

As conditions for volatilizing the organic solvent from the resin varnish after application, it is preferable to specifically heat 50 to 200°C for 0.1 to 90 minutes. If there is no influence on voids after mounting, viscosity adjustment, etc., it is preferable to set the conditions under which the organic solvent volatilizes to 1.5% by mass or less.

The thickness of the film in the film adhesive according to the present embodiment is preferably 10 to 100 µm and more preferably 20 to 50 µm from the viewpoints of visibility, fluidity, and filling.

<Semiconductor device>

The semiconductor adhesive according to the present embodiment is suitably used for a semiconductor device, and is suitable as a semiconductor adhesive, and a semiconductor device in which electrodes of respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a plurality of It is particularly suitably used for sealing the connection portion in a semiconductor device in which electrodes of respective connection portions of a semiconductor chip are electrically connected to each other. Hereinafter, a semiconductor device using the adhesive for semiconductors according to the present embodiment will be described. Electrodes of the connection portion in the semiconductor device may be metal bonding between a bump and a wiring, or metal bonding between a bump and a bump. In the semiconductor device, for example, flip chip connection for obtaining electrical connection through a semiconductor adhesive may be used.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device (a COB type connection mode of a semiconductor chip and a substrate). As shown in Fig. 1(a), the first semiconductor device 100 includes a semiconductor chip 10 and a substrate (wiring circuit board) 20 facing each other, and a semiconductor chip 10 and a substrate 20 A connection bump 30 for connecting the wiring 15 respectively disposed on opposite surfaces of the semiconductor chip 10 and the wiring 15 of the substrate 20 and the semiconductor chip 10 and the substrate 20 It has an adhesive 40 filled with no gaps in the gaps between ). The semiconductor chip 10 and the substrate 20 are flip-chip connected by a wiring 15 and a connection bump 30. The wiring 15 and the connection bump 30 are sealed with an adhesive 40 for semiconductors and are shielded from the external environment.

As shown in Fig. 1(b), the second semiconductor device 200 includes a semiconductor chip 10 and a substrate (wiring circuit board) 20 facing each other, and a semiconductor chip 10 and a substrate 20 And bumps 32 disposed on opposite surfaces of each other, and an adhesive for semiconductors 40 filled without gaps in the gaps between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are flip-chip connected by connecting the bumps 32 facing each other. The bumps 32 are sealed by the adhesive 40 for semiconductors and are shielded from the external environment.

2 is a schematic cross-sectional view showing another embodiment of a semiconductor device (a COC type connection mode between semiconductor chips). As shown in FIG. 2(a), the third semiconductor device 300 is flip-chip connected by the two semiconductor chips 10 by the wiring 15 and the connection bump 30, It is the same as the first semiconductor device 100. As shown in FIG. 2(b), the fourth semiconductor device 400 includes the second semiconductor device 200, except that the two semiconductor chips 10 are flip-chip connected by the bumps 32. ) Is the same.

The semiconductor chip 10 is not particularly limited, and various semiconductors such as elemental semiconductors composed of elements of the same type such as silicon and germanium, and compound semiconductors such as gallium/arsenic and indium/phosphorus can be used.

The substrate 20 is not particularly limited as long as it is a wiring circuit board, and is formed on the surface of an insulating substrate containing glass epoxy resin, polyimide resin, polyester resin, ceramic, epoxy resin, bismaleimide triazine resin, etc. as main components. A circuit board on which a wiring (wiring pattern) is formed by etching away unnecessary portions of a metal layer, a circuit board on which a wiring (wiring pattern) is formed by metal plating on the surface of the insulating substrate, and a conductive material is printed on the surface of the insulating substrate. A circuit board or the like on which the (wiring pattern) is formed can be used.

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

On the surface of the wiring (wiring pattern), a metal layer containing gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. as main components is formed. It may be done. This metal layer may be composed of only a single component, or may be composed of a plurality of components. Further, it may have a structure in which a plurality of metal layers are laminated. Copper and solder are generally used because they are inexpensive. On the other hand, since oxides, impurities, etc. are contained in copper and solder, it is preferable that the semiconductor adhesive has flux activity.

As the material of the conductive protrusion called bump, as the main components, gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. are used, It may be composed of only a single component, or may be composed of a plurality of components. Further, it may be formed so as to form a laminated structure of these metals. The bump may be formed on a semiconductor chip or a substrate. Copper and solder are generally used because they are inexpensive. On the other hand, since oxides, impurities, etc. are contained in copper and solder, it is preferable that the semiconductor adhesive has flux activity.

In addition, a semiconductor device (package) as shown in Fig. 1 or 2 is stacked to form gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), and tin , You may be electrically connected with nickel or the like. For example, as shown in the TSV technology, an adhesive may be interposed between the semiconductor chips, flip-chip connection or lamination, a hole through the semiconductor chip may be formed, and the electrode on the pattern surface may be connected.

3 is a schematic cross-sectional view showing another embodiment of a semiconductor device (semiconductor chip stacked mode (TSV)). As shown in FIG. 3, in the fifth semiconductor device 500, the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor chip 10 through the connection bump 30. , The semiconductor chip 10 and the interposer 50 are flip-chip connected. A semiconductor adhesive 40 is filled in the gap between the semiconductor chip 10 and the interposer 50 without a gap. On the surface of the semiconductor chip 10 on the opposite side to the interposer 50, the semiconductor chip 10 is repeatedly laminated through the wiring 15, the connection bump 30, and the semiconductor adhesive 40 . The wirings 15 on the pattern surface on the front and back of the semiconductor chip 10 are connected to each other by a through electrode 34 filled in a hole penetrating the inside of the semiconductor chip 10. On the other hand, as the material of the through electrode 34, copper, aluminum, or the like can be used.

With such TSV technology, signals can also be acquired from the back surface of a semiconductor chip that is not normally used. In addition, since the through electrode 34 is vertically passed through the semiconductor chip 10, the distance between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 is shortened, and flexible connection This is possible. The semiconductor adhesive according to the present embodiment is suitably used as a sealing material between the opposing semiconductor chips 10 or between the semiconductor chips 10 and the interposer 50 in such TSV technology.

<Method of manufacturing semiconductor device>

In the method for manufacturing a semiconductor device according to the present embodiment, a semiconductor chip and a wiring circuit board, or a plurality of semiconductor chips are connected to each other by using the adhesive for semiconductors according to the present embodiment. The method for manufacturing a semiconductor device according to the present embodiment is, for example, a step of connecting a semiconductor chip and a wiring circuit board to each other through an adhesive, and electrically connecting the respective connection portions of the semiconductor chip and the wiring circuit board to each other to obtain a semiconductor device, or an adhesive And a step of connecting a plurality of semiconductor chips to each other through an electrical connection and electrically connecting respective connection portions of the plurality of semiconductor chips to each other to obtain a semiconductor device.

In the method for manufacturing a semiconductor device according to the present embodiment, the connecting portions can be connected to each other by metal bonding. That is, the respective connection portions of the semiconductor chip and the wiring circuit board are connected to each other by metal bonding, or the respective connection portions of the plurality of semiconductor chips are connected to each other by metal bonding.

As an example of a method for manufacturing a semiconductor device according to the present embodiment, a method for manufacturing the sixth semiconductor device 600 shown in FIG. 4 will be described. The sixth semiconductor device 600 includes a substrate (e.g., a glass epoxy substrate) 60 having a wiring (copper wiring) 15, and a semiconductor chip having a wiring (e.g., copper filler, copper post) 15 ( 10) are connected to each other via an adhesive 40 for semiconductors. The wiring 15 of the semiconductor chip 10 and the wiring 15 of the substrate 60 are electrically connected by connection bumps (solder bumps) 30. A solder resist 70 is disposed on the surface of the substrate 60 on which the wiring 15 is formed, except for the formation position of the connection bump 30.

In the manufacturing method of the sixth semiconductor device 600, first, a semiconductor adhesive (film adhesive or the like) 40 is affixed on the substrate 60 on which the solder resist 70 is formed. The affixing can be performed by heat press, roll lamination, vacuum lamination, or the like. The supply area and thickness of the semiconductor adhesive 40 are appropriately set depending on the size and bump height of the semiconductor chip 10 or the substrate 60. The semiconductor adhesive 40 may be affixed to the semiconductor chip 10, or the semiconductor adhesive 40 may be affixed to the semiconductor wafer and then diced into pieces of the semiconductor chip 10. The semiconductor chip 10 to which the adhesive 40 is affixed may be produced. In this case, as long as it is an adhesive for semiconductors having a high light transmittance, visibility is ensured even when the alignment mark is covered, so that the range to be adhered is not limited not only on the semiconductor wafer (semiconductor chip) but also on the substrate, and the handling property is excellent. .

After attaching the semiconductor adhesive 40 to the substrate 60 or the semiconductor chip 10, the connection bumps 30 on the wiring 15 of the semiconductor chip 10 and the wiring 15 of the substrate 60 are connected. Position alignment using a connecting device such as a flip chip bonder. Then, press the semiconductor chip 10 and the substrate 60 while heating at a temperature equal to or higher than the melting point of the connection bump 30 (in the case of using solder at the connection portion, a temperature of 240°C or higher is preferably applied to the solder portion). , The semiconductor chip 10 and the substrate 60 are connected, and at the same time, the voids between the semiconductor chip 10 and the substrate 60 are sealed and filled with the adhesive 40 for semiconductors. The connection load depends on the number of bumps, but is set in consideration of the absorption of bump height fluctuations and control of the amount of bump deformation. The connection time is preferably a short time from the viewpoint of productivity improvement. It is preferable to melt the solder to remove the oxide film, surface impurities, and the like to form a metal junction at the connection portion.

The short connection time (compression bonding time) means that the time (for example, the time when using solder) is 10 seconds or less at which a temperature of 240°C or higher is applied to the connection portion during connection formation (main compression bonding). The connection time is preferably 5 seconds or less, and more preferably 3 seconds or less.

After alignment, the semiconductor device may be manufactured by temporarily fixing it, melting the solder bumps by heat treatment in a reflow furnace, and connecting the semiconductor chip and the substrate. Temporary fixing, since the necessity of forming a metal bonding is not significantly required, compared to the above-described main compression bonding, it may be of a lowering weight, a short time, and a low temperature, and there are advantages such as improvement in productivity and prevention of deterioration of the connection portion. After connecting the semiconductor chip and the substrate, heat treatment may be performed in an oven or the like to cure the adhesive. The heating temperature is a temperature at which curing of the adhesive proceeds, preferably almost completely. The heating temperature and heating time may be appropriately set. In this case, the obtained semiconductor device includes a cured product of an adhesive.

Example

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

The compounds used in each Example and Comparative Example are as follows.

(a) epoxy resin

-Polyfunctional solid epoxy resin containing triphenolmethane skeleton (manufactured by Mitsubishi Chemical Co., Ltd., brand name "EP1032H60", hereinafter referred to as "EP1032".)

Epoxy resin containing naphthalene skeleton (manufactured by DIC Corporation, brand name "HP4032D")

-Bisphenol F type liquid epoxy resin (Mitsubishi Chemical Co., Ltd. make, brand name "YL983U", hereinafter referred to as "YL983".)

-Flexible epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., brand name "YL7175", hereinafter referred to as "YL7175".)

(b) hardener

-2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Kasei Kogyo Co., Ltd., brand name "2MAOK-PW" , Hereinafter referred to as "2 MAOK".)

(c) a high molecular weight component with a weight average molecular weight of 10000 or more

・Acrylic resin (manufactured by Kuraray Co., Ltd., brand name "Kurati LA4285", Mw/Mn=1.28, weight average molecular weight Mw:80000)

(d) filler

Inorganic filler

-Epoxy surface-treated nano silica filler (manufactured by Admatex, brand name "50 nm SE-AH1", average particle diameter: about 50 nm, hereinafter referred to as "SE nano silica".)

-Inorganic silica filler (manufactured by Admatex, brand name "SE2050", average particle diameter: 0.5 µm, hereinafter referred to as "SE2050".)

-Inorganic silica filler (manufactured by Admatex, brand name "SE2050SEJ", average particle diameter: 0.5 µm, hereinafter referred to as "SE2050SEJ".)

(e) flux agent

Glutaric acid (manufactured by Sigma-Aldrich Japan Kodo Co., Ltd., melting point: about 97℃)

<Production of film adhesive>

(Example 1)

11.25 g of epoxy resin (6.8 g for ``EP1032'', 0.75 g for ``HP4032D'', 1.5 g for ``YL983'', 2.2 g for ``YL7175''), 0.6 g of curing agent ``2MAOK'', 0.45 g of glutaric acid, inorganic filler `` SE nano silica” 35.3 g, acrylic resin “LA4285” 2.0 g, and cyclohexanone (the amount of which the solid content in the resin varnish becomes 47 mass%) was added, and beads having a diameter of 1.0 mm were added by the same mass as the solid content, and beads It stirred for 30 minutes with a mill (made by Fritz Japan Co., Ltd., planetary pulverizer P-7). Then, the beads used for stirring were removed by filtration, and a resin varnish was obtained.

The obtained resin varnish was coated on a base film (manufactured by Teijin DuPont Film Co., Ltd., brand name ``Purex A54'') with a small precision coating device (manufactured by Yasui Seiki Co., Ltd.), and the coated resin varnish was applied in a clean oven ( (Manufactured by SPEC Co., Ltd.) and dried (100° C./5 minutes) to obtain a film adhesive. The thickness was produced to be 0.02 mm.

(Example 2)

A film adhesive was produced in the same manner as in Example 1, except that the epoxy resin "HP4032D" was increased to 1.5 g and the epoxy resin "YL983" was reduced to 0.75 g.

(Comparative Example 1)

The same as in Example 1, except that 2.3 g of an inorganic silica filler (manufactured by Admatex, brand name “SE2050”, average particle diameter: 0.5 μm) was added without blending the epoxy resins “YL7175” and “HP4032D”. To prepare a film adhesive.

(Comparative Example 2)

Except for adding 3.3 g of inorganic silica filler (manufactured by Admatex, brand name “SE2050SEJ”, average particle diameter: 0.5 μm), reducing “SE nano silica” to 27.9 g, and reducing “LA4285” to 0.5 g , In the same manner as in Example 1, a film adhesive was produced.

In Table 1, the combination of Examples 1-2 and Comparative Examples 1-2 is put together and shown.

<Evaluation>

Hereinafter, the evaluation method of the film adhesive obtained in Examples and Comparative Examples is shown.

(1) Preparation of thixotropy measurement sample

The prepared film-type adhesive was laminated (laminated) with a table-top laminator (manufactured by Mirror Corporation, brand name "Hot Dog GK-13DX") until the total thickness became 0.4 mm (400 μm), and 7.3 mm long , Cut into a size of 7.3 mm in width to obtain a measurement sample.

(2) Measurement of thixotropy

With respect to the obtained measurement sample, a shear viscosity measuring device (manufactured by T-A Instruments Japan Co., Ltd., trade name "ARES") was used to continuously change the frequency from 1 Hz to 70 Hz at constant conditions of 120°C at 0.1 Hz per second. The viscosity when changed was measured, and the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz was taken as the thixotropic value.

(3) Manufacturing method of semiconductor device

Cut off the produced film adhesive (7.3 mm long, 7.3 mm wide, 0.045 mm thick), and a semiconductor chip with solder bumps (chip size: 7.3 mm long, 7.3 mm wide, 0.15 mm thick, bump height: copper filler + solder (A total of about 45 µm, bump number 328, pitch 80 µm). Next, a semiconductor chip with solder bumps affixed with a film adhesive was mounted on a glass epoxy substrate (glass epoxy substrate thickness: 420 μm, copper wiring thickness: 9 μm) with a flip chip bonder FCB3 (manufactured by Panasonic Corporation). (Mounting conditions: pressure bonding head temperature 350°C/5 second/0.5 MPa), a semiconductor device similar to that of FIG. 4 was obtained. The stage temperature was 80°C.

(4) Coverage evaluation method

The semiconductor device obtained in the above-described (3) method for manufacturing a semiconductor device was observed from the upper side of the upper chip with a microscope (manufactured by Giens Co., Ltd.), and the protruding width of the resin from the chip end was measured. The protruding width is the protruding width W ₁ (unit: µm) of the resin from the center of one side of the chip, and the protrusion of the resin from a position at the center of 0.2 mm from one end (corner of the chip) of the one side. The protruding width W ₂ (unit: μm) was measured, and the ratio (W ₂ /W ₁ ) of both was calculated. On the other hand, W ₂ is the smaller of the width of the protruding resin from the center 0.2 mm from one end of the chip and the protruding width of the resin from the center 0.2 mm from the other end. Value. This ratio (W ₂ /W ₁ ) was measured for all four sides of the chip, and the average value was determined as "coverage property".

Coverage is an index indicating whether or not the adhesive resin is evenly spread to the edge of the chip in the semiconductor device. Since it is preferable that there is no difference in the protruding width of the corner portion of the semiconductor device and the center portion of the side, the coverage property closer to 1 is better.

Table 1 shows the measurement results of thixotropic values and the evaluation results of coverage properties.

From the evaluation results of Table 1, Examples 1 and 2 having a thixotropy value of 3.1 or less had a coverage property exceeding 0.4, but Comparative Example 1 and Comparative Example 2 having a thixotropy value of more than 3.1 and a large coverage property It became less than 0.4. From these points, it was confirmed that the coverage property was improved according to the film-type semiconductor adhesive of the present disclosure having a low thixotropy value.

10: semiconductor chip
15: wiring
20, 60: substrate
30: connection bump
32: bump
34: through electrode
40: semiconductor adhesive
50: interposer
70: solder resist
100, 200, 300, 400, 500, 600: semiconductor device

Claims (8)

In a semiconductor device in which electrodes of respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which electrodes of respective connection portions of a plurality of semiconductor chips are electrically connected to each other, at least a part of the connection portion As an adhesive for semiconductors used for sealing of,
The thixotropic value of the semiconductor adhesive is 1.0 or more and 3.1 or less,
The thixotropy value is the viscosity of a sample in which the semiconductor adhesive is laminated to a thickness of 400 μm, when the frequency is continuously changed from 1 Hz to 70 Hz under a constant condition of a temperature of 120°C with a shear viscosity measuring device. The adhesive for semiconductors is a value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz. The adhesive for semiconductors according to claim 1, comprising (a) an epoxy resin, (b) a curing agent, and (c) a high molecular weight component having a weight average molecular weight of 10000 or more. The semiconductor adhesive according to claim 2, further comprising (d) a filler. The adhesive for semiconductors according to claim 2 or 3, further comprising (e) a flux agent. The adhesive for semiconductors according to any one of claims 2 to 4, wherein the polydispersity Mw/Mn of the high molecular weight component (c) with a weight average molecular weight of 10000 or more is 3 or less. The semiconductor adhesive according to any one of claims 2 to 5, wherein a part or all of the material contained in the semiconductor adhesive is soluble in cyclohexanone. The adhesive for semiconductors according to any one of claims 1 to 6, which is a film type. Using the semiconductor adhesive according to any one of claims 1 to 7, the semiconductor chip and the wiring circuit board are aligned through the semiconductor adhesive by a connection device, and connected to each other, and the semiconductor chip and the wiring circuit A step of electrically connecting electrodes of each connection portion of a substrate to each other and sealing at least a part of the connection portion with the semiconductor adhesive, or by aligning a plurality of semiconductor chips through the semiconductor adhesive by a connection device And a step of connecting to each other, electrically connecting electrodes of respective connecting portions of a plurality of semiconductor chips to each other, and sealing at least a part of the connecting portions with the semiconductor adhesive.

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