KR102570823B1 - Adhesive for semiconductor and manufacturing method of semiconductor device using the same - Google Patents

Abstract

The present invention relates to 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 part of, the thixotropy value of the adhesive for semiconductors is 1.0 or more and 3.1 or less, and the thixotropy value is measured for the shear viscosity of a sample in which the adhesive for semiconductors is laminated to a thickness of 400 μm The device measures the viscosity when the frequency is continuously changed from 1 Hz to 70 Hz under certain conditions of a temperature of 120 ° C., and the viscosity value at 7 Hz is divided by the viscosity value at 70 Hz. Provides an adhesive for semiconductors .

Description

Adhesive for semiconductor and manufacturing method of semiconductor device using the same

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

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

As the flip chip connection method, a method of metal bonding using solder, tin, gold, silver, copper, etc., a method of metal bonding by applying ultrasonic vibration, a method of maintaining mechanical contact by the shrinkage force of a resin, etc. are known. From the viewpoint of the reliability of the connecting portion, a method of metal bonding 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 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 connection parts (bumps or wires) are formed on semiconductor chips to connect semiconductor chips (see, for example, Patent Document 1 below). ).

In packages where further miniaturization, thinning, and high functionality are strongly demanded, chip stack type packages, POP (Package On Package), and TSV (Through-Silicon Via), etc., in which the above-mentioned connection methods are stacked and multi-staged, are also beginning to spread widely. . Since packages can be made smaller by arranging them in a three-dimensional shape rather than a flat shape, 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 next-generation semiconductor wiring technologies. .

Patent Document 1: Japanese Unexamined Patent Publication No. 2016-102165

[0002] In a flip chip package where high functionality, high integration, and low cost are progressing, it is required to suppress resin protrusion during chip mounting and to mount chips at high density for high productivity. For this reason, if the load for crimping is light, the resin protrusion width is suppressed, but there is a concern that the edge portion of the chip becomes insufficient in resin, leading to chip peeling or the like.

The present disclosure discloses an adhesive for semiconductors capable of controlling the shape of resin protruding during chip mounting and allowing the resin to protrude in a shape along the chip side surface to obtain a semiconductor device without shortage of resin during mounting, and a semiconductor device using the same. Its main purpose is to provide a manufacturing method for

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

Further, another aspect of the present disclosure is [2] the adhesive for semiconductors described in [1] above, which contains (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.

Moreover, another side surface of this indication is [3] (d) The adhesive agent for semiconductors as described in said [2] which further contains a filler.

Further, another aspect of the present disclosure is the adhesive for semiconductors described in [2] or [3], which further contains [4] (e) a flux agent.

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

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

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

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

According to the present disclosure, by controlling the thixotropy value of the adhesive for semiconductors, the resin protrusion shape to the outer peripheral portion of the chip during semiconductor device mounting is controlled, and the resin protrudes in a shape along the chip side surface, thereby suppressing resin shortage. can Further, according to the present disclosure, a semiconductor device using such an adhesive for semiconductors and a manufacturing method thereof can be provided.

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

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to drawings where necessary. In the drawings, the same reference numerals are assigned to the same or equivalent parts, and overlapping descriptions are omitted. In addition, positional relationships such as up, down, left, right, etc. are based on the positional relationships shown in the drawings unless otherwise specified. In addition, the dimensional ratios in the drawings are not limited to the ratios shown.

In this specification, a numerical range expressed using "-" indicates a range including the numerical values described before and after "-" as the minimum and maximum values, respectively. In the numerical ranges recited step by step in this specification, the upper or lower values of the numerical ranges of any step may be combined with the upper or lower values of the numerical ranges of other steps in any combination. In the numerical range described in this specification, the upper limit or lower limit of the numerical range may be substituted with the value shown in the examples. With "A or B", either one of A and B may be included, and both may be included. The materials exemplified in this specification can be used singly or in combination of two or more, unless otherwise specified. In this specification, "(meth)acryl" means acryl or methacryl corresponding to it.

<Adhesives for semiconductors>

The adhesive for semiconductors according to this embodiment is a semiconductor device in which electrodes of each connection part of a semiconductor chip and a wiring circuit board are electrically connected to each other, or electrodes of each connection part 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 semiconductor adhesive according to the present embodiment has a thixotropy value of 1.0 or more and 3.1 or less. The thixotropy value is obtained by measuring the viscosity 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 for a sample in which the semiconductor adhesive is laminated to a thickness of 400 μm. , is the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz. If the thixotropy value is 3.1 or less, the semiconductor adhesive can sufficiently flow even at the edge of the chip where the shear applied during chip mounting is the smallest, and 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, (d) a filler, and (e) a flux agent. it is desirable if

((a) component: epoxy resin)

Examples of the epoxy resin of component (a) include epoxy resins having two or more epoxy groups in the molecule, bisphenol A type epoxy resins, bisphenol F type epoxy resins, naphthalene type epoxy resins, phenol novolak type epoxy resins, and cresol no. A rockfish-type epoxy resin, a phenolaralkyl-type epoxy resin, a biphenyl-type epoxy resin, a triphenylmethane-type epoxy resin, a dicyclopentadiene-type epoxy resin, various multifunctional epoxy resins, and the like can be used. (a) component can be used individually by 1 type or in combination of 2 or more types.

The content of component (a) is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, still more preferably 20 to 40% by mass based on the total solid content of the adhesive for semiconductors. 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 increase excessively, and warpage of the package is easily reduced. In addition, by setting the content of component (a) within the above range, it is easy to control the thixotropy value of the adhesive for semiconductors to 1.0 or more and 3.1 or less. Since the thixotropy value tends to decrease when the resin component is small and the filler content is high, it becomes easy to lower the thixotropy value by setting the content of component (a) to 50% by mass or less.

(Component (b): curing agent)

The adhesive for semiconductors according to the present embodiment contains (b) a curing agent. Examples of the curing agent include phenol resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, and phosphine-based curing agents. When the component (b) contains a phenolic hydroxyl group, an acid anhydride, amines or imidazoles, it is easy to exhibit a flux activity that suppresses the formation of an oxide film on the connection portion, and the connection reliability and insulation reliability can be easily improved. Hereinafter, each curing agent is described.

(b-i) phenolic resin curing agent

Examples of the phenolic resin-based curing agent include curing agents having two or more phenolic hydroxyl groups in the molecule, phenol novolak resins, cresol novolac resins, phenol aralkyl resins, cresol naphthol formaldehyde polycondensates, and triphenylmethane type polyfunctional phenols. resins, various polyfunctional phenolic resins, and the like can be used. The phenol resin-based 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. When the equivalence ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve, and when it is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively, the water absorption rate is suppressed low, and the insulation reliability tends to further improve. there is

(b-ii) acid anhydride curing agent

As the acid anhydride-based curing agent, methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, ethylene glycol bisanhydrotrimellitate and the like can be used. Acid anhydride-based curing agents 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, adhesiveness and storage stability. , more preferably 0.5 to 1.0. When the equivalence ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve. When the equivalence ratio is 1.5 or less, unreacted acid anhydrides do not remain excessively, the water absorption rate is suppressed to a low level, and the insulation reliability tends to further improve. there is.

(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, adhesiveness and storage stability. this is more preferable When the equivalence ratio is 0.3 or more, curability is improved and adhesion tends to be improved, and when it is 1.5 or less, unreacted amines do not remain in excess and insulation reliability tends to be further improved.

(b-iv) imidazole curing agent

As the imidazole-based curing agent, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 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'-unde 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, adducts of epoxy resins and imidazoles, and the like. Among these, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, and 1-cyanoethyl-2- from the viewpoint of further excellent curability, storage stability and connection reliability. 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-triazine isocyanuric 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. Moreover, it is good also as a latent hardener which microencapsulated these.

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 component (a). When the content of the imidazole-based curing agent is 0.1 parts by mass or more, curability tends to improve, and when it is 20 parts by mass or less, the adhesive composition does not cure before metal bonding is formed, and connection failure tends to be less likely to occur. there is.

(b-v) phosphine curing agent

Examples of the phosphine curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenyl borate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

The content of the phosphine curing agent is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of component (a). When the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to improve, and when it is 10 parts by mass or less, the semiconductor adhesive does not cure before metal bonding is formed, and connection failure tends to be less likely to occur. there is.

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

As the component (b), from the viewpoint of excellent curing properties, a combination of a phenol resin-based curing agent and an imidazole-based curing agent, a combination of an acid anhydride-based curing agent and an imidazole-based curing agent, a combination of an amine-based curing agent and an imidazole-based curing agent, and an imidazole-based curing agent Single use is preferred. Since productivity improves when connected in a short time, single use of an imidazole-based curing agent with excellent rapid curing properties is more preferable. 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 be easily suppressed.

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

(c) As high molecular weight components (excluding compounds corresponding to component (a)) having a weight average molecular weight of 10000 or more, phenoxy resins, polyimide resins, polyamide resins, polycarbodiimide resins, cyanate ester resins, ( meth)acrylic resins, polyester resins, polyethylene resins, polyethersulfone resins, polyetherimide resins, polyvinyl acetal resins, polyurethane resins, acrylic rubbers, and the like, and among them, excellent heat resistance and film formability. In, phenoxy resins, polyimide resins, (meth) acrylic resins, acrylic rubbers, cyanate ester resins, and polycarbodiimide resins are preferred, and phenoxy resins, polyimide resins, (meth) acrylic resins, and acrylic rubbers are more preferable (c) Component can also be used individually or as a mixture or copolymer of 2 or more types.

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

Although the weight average molecular weight of component (c) is 10000 or more in terms of polystyrene, in order to show good film formation property alone, 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 that the film formability is lowered. In addition, in this specification, a weight average molecular weight means the weight average molecular weight at the time of measuring by polystyrene conversion using high performance liquid chromatography (C-R4A by Shimadzu Corporation).

(c) It is preferable that it is 3 or less, and, as for polydispersity Mw/Mn of component, it is more preferable that it is 2.5 or less. It is considered that when the Mw/Mn is 3 or less, there is a tendency that there is little variation in molecular weight and the thixotropy value tends to be low.

((d) component: filler)

As a filler of (d) component, an insulating inorganic filler etc. are mentioned. Especially, it is more preferable in it being 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, and boron nitride. Among these, silica, alumina, titanium oxide, and boron nitride are preferable, and silica, alumina, and 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. An insulating inorganic filler can be used individually by 1 type or in combination of 2 or more types. The shape, particle size, and content of component (d) are not particularly limited.

From the standpoint of further excellent insulation reliability, component (d) is preferably insulating. It is preferable that the adhesive for semiconductors concerning this embodiment does not contain electroconductive metal fillers, such as a silver filler and a solder filler.

Component (d) is preferably a filler subjected to surface treatment from the viewpoint of improving dispersibility and adhesive strength. As the surface treatment agent, glycidyl (epoxy-based) compounds (excluding compounds corresponding to component (a)), amine-based compounds, phenyl-based compounds, phenylamino-based compounds, (meth)acrylic compounds (for example, 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.]

Examples of the filler surface-treated with a compound having a structure represented by Formula (1) include acrylic surface-treated fillers in which R ¹¹ is a hydrogen atom, methacrylic surface-treated fillers in which R ¹¹ is a methyl group, and ethacrylic surfaces in which R ¹¹ is an ethyl group. treatment fillers, etc., and from the viewpoint of the reactivity between the resin contained in the adhesive for semiconductors and the surface of the semiconductor substrate, and the bond formation, acrylic surface treatment fillers and methacrylic surface treatment fillers in which R ¹¹ is not bulky desirable. R ¹² is also not particularly limited, but a higher weight average molecular weight is preferable because there are fewer volatile components.

[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 reducing the reactivity, R ²¹ , R ²² and R ²³ are preferably relatively bulky groups, and may be, for example, hydrogen atoms or alkyl groups. Further, R ²¹ , R ²² and R ²³ may be monovalent organic groups that improve the reactivity of the vinyl group. R ²⁴ is also not particularly limited, but is preferably higher in weight average molecular weight from the viewpoint of easily reducing voids because it is difficult to volatilize. Further, R ²¹ , R ²² , R ²³ and R ²⁴ may be selected for ease of surface treatment.

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

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

The content of component (d) is preferably 20 to 80% by mass, more preferably 30 to 75% by mass, and still more preferably 50 to 75% by mass based on the total amount of the adhesive for semiconductors. When the content of the component (d) is 20% by mass or more, there is no fear that the adhesive force is lowered or the reflow resistance is lowered. In addition, when the content of component (d) is 40% by mass or less, there is no fear that connection reliability is lowered due to thickening. The higher the content of component (d), the lower the thixotropy value.

((e) component: flux agent)

The adhesive for semiconductors may further contain (e) a flux agent exhibiting flux activity (activity for removing oxides, impurities, etc.). Examples of the flux agent include nitrogen-containing compounds having unshared electron pairs (imidazoles, amines, etc., excluding those included in component (b)), carboxylic acids, phenols, and alcohols. On the other hand, compared to alcohols, carboxylic acids strongly express flux activity and tend to improve connectivity.

It is preferable that it is 0.2-3 mass %, and, as for content of component (e), it is more preferable that it is 0.4-1.8 mass % on the basis of the whole solid content of the adhesive for semiconductors from a viewpoint of solder wettability.

You may further mix|blend an ion trapper, antioxidant, a silane coupling agent, a titanium coupling agent, a leveling agent, etc. to the adhesive agent for semiconductors. These may be used individually by 1 type, and may be used in combination of 2 or more types. What is necessary is just to adjust suitably so that the effect of each additive may express about these compounding quantities.

<Method of manufacturing adhesive for semiconductors>

It is preferable that the adhesive for semiconductors which concerns on this embodiment is a film type (film adhesive) from a viewpoint of productivity improvement. The manufacturing method of a film adhesive is demonstrated below.

First, component (a), component (b), component (c), and other components as needed are added to an organic solvent, and then dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a resin varnish. Thereafter, a resin varnish is applied on the base film subjected to the release treatment 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. form an adhesive. Alternatively, a film adhesive may be formed on the wafer by a method of forming a film by spin-coating a resin varnish on a wafer or the like before reducing the organic solvent by heating and then drying the solvent.

As the organic solvent used in the preparation of the resin varnish, those having properties capable of uniformly dissolving or dispersing each component are preferred, such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide , diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. there is. Among these, it is preferable to use cyclohexanone from a viewpoint of film forming property, and it is preferable that part or all of the material contained in the adhesive for semiconductors is soluble in cyclohexanone. That is, it is preferable that part or all of the material contained in the resin varnish is a cyclohexanone melt. These organic solvents can be used individually or in combination of 2 or more types. Stirring and mixing and kneading at the time of resin varnish preparation can be performed using, for example, a stirrer, a drum grinder, a 3-roll, a ball mill, a bead mill, or a homodisper.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing the organic solvent, and a polyester film, a polypropylene film, a polyethylene terephthalate film, a polyimide film, a polyetherimide film, and a polyether film. A naphthalate film, a methylpentene film, etc. are mentioned. As a base film, it is not limited to the single layer thing containing 1 type of these films, A multilayer film containing 2 or more types of films may be sufficient.

As conditions at the time of volatilizing the organic solvent from the resin varnish after application|coating, specifically, it is preferable to heat at 50-200 degreeC for 0.1-90 minutes. It is preferable to set it as the condition that the organic solvent volatilizes to 1.5 mass % or less, if there is no effect on void after mounting, viscosity adjustment, etc.

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 properties.

<Semiconductor device>

The adhesive for semiconductors according to the present embodiment is suitably used for semiconductor devices, is suitable as an adhesive for semiconductors, and 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 plurality of In a semiconductor device in which electrodes of respective connection parts of a semiconductor chip are electrically connected to each other, it is particularly suitably used for sealing connection parts. Hereinafter, a semiconductor device using the adhesive for semiconductors according to the present embodiment will be described. The electrodes of the connection part in the semiconductor device may be either metal junctions between bumps and wires or metal junctions between bumps and bumps. In the semiconductor device, for example, a flip chip connection in which electrical connection is obtained through an adhesive for semiconductors may be used.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device (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 wirings 15 respectively disposed on opposite surfaces of the semiconductor chip 10 and the connection bumps 30 connecting the wirings 15 of the substrate 20 to each other, the semiconductor chip 10 and the substrate 20 ) has an adhesive 40 filled without gaps in the gaps between them. The semiconductor chip 10 and the substrate 20 are flip-chip connected by wiring 15 and connection bumps 30 . The wiring 15 and the connection bumps 30 are sealed with the 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 It has bumps 32 respectively disposed on the surfaces facing each other, and an adhesive 40 for semiconductors filled in gaps between the semiconductor chip 10 and the substrate 20 without gaps. The semiconductor chip 10 and the substrate 20 are flip-chip connected by connecting the opposing bumps 32 to each other. The bump 32 is sealed with the adhesive 40 for semiconductors and is shielded from the external environment.

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

The semiconductor chip 10 is not particularly limited, and various types of semiconductors, such as elemental semiconductors composed of the same type of elements 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 or the like as a main component. A circuit board on which wiring (wiring pattern) is formed by etching away unnecessary portions of the metal layer, a circuit board on which wiring (wiring pattern) is formed by metal plating on the surface of the insulating board, and wiring by printing a conductive material on the surface of the insulating board. A circuit board or the like on which (wiring pattern) is formed can be used.

Connections such as wirings 15 and bumps 32 are made of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), nickel, tin, and lead as main components. 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 (the main component of which is, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. is formed. It may be. This metal layer may be composed of only a single component or may be composed of a plurality of components. Furthermore, you 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, and the like are contained in copper and solder, the adhesive for semiconductors preferably has flux activity.

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

In addition, by stacking semiconductor devices (packages) as shown in FIG. 1 or 2, gold, silver, copper, solder (the main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin , nickel, etc. may be electrically connected. For example, as seen in TSV technology, flip chip connection or stacking may be performed by interposing an adhesive between semiconductor chips, forming a hole penetrating the semiconductor chips, and connecting them to the electrodes on the pattern surface.

Fig. 3 is a schematic cross-sectional view showing another embodiment of a semiconductor device (semiconductor chip stack type 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 , thereby , the semiconductor chip 10 and the interposer 50 are flip-chip connected. The gap between the semiconductor chip 10 and the interposer 50 is filled with the adhesive 40 for semiconductors without gaps. On the surface of the semiconductor chip 10 on the opposite side to the interposer 50, the semiconductor chip 10 is repeatedly laminated via wirings 15, connection bumps 30, and adhesives 40 for semiconductors. . The wirings 15 on the pattern surface on the front and back of the semiconductor chip 10 are connected to each other by through electrodes 34 filled in holes penetrating the inside of the semiconductor chip 10 . On the other hand, as a material for the through electrode 34, copper, aluminum, or the like can be used.

With this TSV technology, signals can be acquired even from the backside of a semiconductor chip that is not normally used. In addition, since the penetration electrode 34 is passed vertically 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 the connection is flexible. this is possible The adhesive for semiconductors concerning this embodiment is suitably used as a sealing material between opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 in such TSV technology.

<Method of manufacturing semiconductor device>

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

In the semiconductor device manufacturing method according to the present embodiment, the connection portions can be connected to each other by metal bonding. That is, each connection part of the semiconductor chip and the wiring circuit board is connected to each other by metal bonding, or each connection part of a plurality of semiconductor chips is 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., glass epoxy substrate) 60 having wiring (copper wiring) 15, and a semiconductor chip (e.g., copper filler, copper post) 15 having wiring ( 10) are connected to each other via the 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 wirings 15 are formed, excluding the formation positions of the connection bumps 30 .

In the manufacturing method of the 6th semiconductor device 600, first, the adhesive agent for semiconductors (film adhesive etc.) 40 is affixed on the board|substrate 60 on which the solder resist 70 was formed. Attachment can be performed by hot press, roll lamination, vacuum lamination, or the like. The supply area and thickness of the adhesive 40 for semiconductors are suitably set according to the size of the semiconductor chip 10 or the substrate 60, the bump height, and the like. The semiconductor adhesive 40 may be affixed to the semiconductor chip 10, and after affixing the semiconductor adhesive 40 to the semiconductor wafer, by dicing to separate into the semiconductor chip 10, for semiconductors You may manufacture the semiconductor chip 10 to which the adhesive agent 40 was stuck. In this case, if it is an adhesive for semiconductors having a high light transmittance, since visibility is ensured even if the alignment mark is covered, the range of sticking is not limited not only on the semiconductor wafer (semiconductor chip) but also on the substrate, and the handleability is excellent. .

After attaching the adhesive 40 for semiconductors to the substrate 60 or the semiconductor chip 10, the connection bump 30 on the wiring 15 of the semiconductor chip 10 and the wiring 15 of the substrate 60 Alignment is performed using a connection device such as a flip chip bonder. Then, the semiconductor chip 10 and the substrate 60 are pressed while heating at a temperature equal to or higher than the melting point of the connection bump 30 (when solder is used for 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 gap between the semiconductor chip 10 and the substrate 60 is sealed and filled with the adhesive 40 for semiconductors. The connection load depends on the number of bumps, but is set in consideration of absorbing height fluctuations of bumps, controlling bump deformation amount, and the like. As for connection time, a short time is preferable from a viewpoint of productivity improvement. It is preferable to melt the solder to remove an oxide film, impurities on the surface, and the like, and form a metal junction at the connecting portion.

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

After alignment, a semiconductor device may be manufactured by temporarily fixing, melting the solder bumps by heating in a reflow furnace, and connecting the semiconductor chip and the substrate. Temporary fixing does not significantly require the formation of metal joints, so it may be performed at a lower load, a shorter time, and at a lower temperature than the above-mentioned main pressing, and brings advantages such as improved productivity and prevention of deterioration of the connecting 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 the adhesive is cured, preferably almost completely cured. What is necessary is just to set heating temperature and heating time suitably. 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 by way of 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

- Triphenolmethane skeleton-containing multifunctional solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "EP1032H60", hereinafter referred to as "EP1032")

・Naphthalene backbone-containing epoxy resin (manufactured by DIC Co., Ltd., trade name “HP4032D”)

- Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YL983U", hereinafter referred to as "YL983")

- Flexible epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "YL7175", hereinafter referred to as "YL7175")

(b) curing agent

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

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

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

(d) filler

inorganic filler

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

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

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

(e) flux agent

・Glutaric acid (manufactured by Sigma-Aldrich Japan Kodokaisha, melting point: about 97°C)

<Production of film adhesive>

(Example 1)

Epoxy resin 11.25 g (6.8 g for "EP1032", 0.75 g for "HP4032D", 1.5 g for "YL983", 2.2 g for "YL7175"), curing agent "2MAOK" 0.6 g, glutaric acid 0.45 g, inorganic filler " 35.3 g of “SE nano silica”, 2.0 g of acrylic resin “LA4285”, and cyclohexanone (an amount in which the solid content in the resin varnish is 47% by mass) were added, beads having a diameter of 1.0 mm were added in the same mass as the solid content, and beads It stirred for 30 minutes with a mill (Private Japan Co., Ltd. product, planetary type fine grinder P-7). Then, the beads used for stirring were removed by filtration to obtain a resin varnish.

The obtained resin varnish is coated on a base film (manufactured by Teijin Dupont Film Co., Ltd., trade name "Purex A54") with a small precision coating device (manufactured by Yasui Seiki Co., Ltd.), and the coated resin varnish is placed in a clean oven ( It was made to dry (100 degreeC/5 minutes) in (Espec Co., Ltd. make), and the film adhesive was obtained. The thickness was manufactured to be 0.02 mm.

(Example 2)

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

(Comparative Example 1)

Same as Example 1 except that the epoxy resins "YL7175" and "HP4032D" were not blended and 2.3 g of inorganic silica filler (manufactured by Admatex Co., Ltd., trade name "SE2050", average particle diameter: 0.5 µm) was added. Thus, a film adhesive was produced.

(Comparative Example 2)

Except for adding 3.3 g of inorganic silica filler (manufactured by Admatex Co., Ltd., trade 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.

Table 1 summarizes the formulations of Examples 1 and 2 and Comparative Examples 1 and 2.

<evaluation>

Hereinafter, the evaluation method of the film adhesive obtained by the Example and the comparative example is shown.

(1) Fabrication of thixotropy measurement sample

The prepared film adhesive was laminated (laminated) with a desk laminator (manufactured by Mirror Corporation, trade name "Hot Dog GK-13DX") until the total thickness reached 0.4 mm (400 µm), and the length was 7.3 mm. , cut into a size of 7.3 mm in width to obtain a measurement sample.

(2) Measurement of thixotropy value

With respect to the obtained measurement sample, the frequency was continuously set at 0.1 Hz per second from 1 Hz to 70 Hz under constant conditions of a temperature of 120 ° C. 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 used as the thixotropy value.

(3) Manufacturing method of semiconductor device

The prepared film adhesive was cut (length 7.3 mm, width 7.3 mm, thickness 0.045 mm), and a semiconductor chip with solder bumps (chip size: length 7.3 mm, width 7.3 mm, thickness 0.15 mm, bump height: copper filler + solder total of about 45 μm, number of bumps 328, pitch 80 μm). Next, the semiconductor chip with solder bumps to which the film adhesive was attached 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: compression head temperature of 350°C/5 seconds/0.5 MPa), and a semiconductor device similar to that in FIG. 4 was obtained. The stage temperature was 80°C.

(4) Coverage evaluation method

The semiconductor device obtained in the above (3) semiconductor device manufacturing method was observed with a microscope (manufactured by Keyence Corporation) from above the upper chip, and the resin protrusion width from the chip end was measured. The protrusion width is defined as the protrusion 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 0.2 mm from the center side of one end of the one side (edge of the chip). The output width W ₂ (unit: μm) was measured, and the ratio of both (W ₂ /W ₁ ) was determined. On the other hand, W ₂ is the smaller of the resin protrusion width from a position on the center side of 0.2 mm from one end of the above-mentioned one side of the chip and the resin protrusion width from a position on the center side of 0.2 mm from the other end. is the 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”.

The coverage property is an index indicating whether the adhesive resin spreads evenly to the corners of the chip in the semiconductor device. Since it is preferable that there is no difference in the protrusion width between the corner portion of the semiconductor device and the center portion of the side, the closer the coverage property is to 1, the better.

Table 1 shows the measurement result of the thixotropy value and the evaluation result of the coverage property.

From the evaluation results in Table 1, Example 1 and Example 2 having a thixotropy value of 3.1 or less had coverage exceeding 0.4, but Comparative Example 1 and Comparative Example 2 having a large thixotropy value exceeding 3.1 had coverage became less than 0.4. From these points, according to the film adhesive for semiconductors of the present disclosure having a low thixotropy value, it was confirmed that the coverage property increased.

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

Claims (8)

In a semiconductor device in which electrodes of each connection part of a semiconductor chip and a wiring circuit board are electrically connected to each other, or in a semiconductor device in which electrodes of each connection part of a plurality of semiconductor chips are electrically connected to each other, at least a part of the connection part As an adhesive for semiconductors used for sealing,
(a) an epoxy resin, (b) a curing agent, and (c) a high molecular weight component having a weight average molecular weight of 40000 or more;
The thixotropy value of the semiconductor adhesive is 1.0 or more and 3.1 or less,
The thixotropy value measures the viscosity 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 for a sample in which the semiconductor adhesive is laminated to a thickness of 400 μm. Thus, 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 of Claim 1 which further contains (d) filler. The adhesive for semiconductors according to claim 1, further comprising (e) a flux agent. The adhesive for semiconductors of Claim 1 whose polydispersity Mw/Mn of said (c) high molecular weight component of 40000 or more weight average molecular weight is 3 or less. The adhesive for semiconductors according to claim 1, wherein part or all of the materials contained in the adhesive for semiconductors are soluble in cyclohexanone. The adhesive for semiconductors according to claim 1, which is in the form of a film. Using the adhesive for semiconductors according to any one of claims 1 to 6, positioning of the semiconductor chip and the wiring circuit board is performed by means of a connection device through the adhesive for semiconductors, and the semiconductor chip and the wiring circuit are connected to each other. A step of electrically connecting the electrodes of each connecting portion of the substrate to each other and sealing at least a part of the connecting portion with the adhesive for semiconductors, or positioning a plurality of semiconductor chips via the adhesive for semiconductors by a connecting device, , A method for manufacturing a semiconductor device comprising 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 adhesive for semiconductors.

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