TWI782177B - Adhesive for semiconductor and manufacturing method of semiconductor device using the same - Google Patents

Abstract

An adhesive for semiconductors, a semiconductor device in which the electrodes of the respective connection parts of a semiconductor wafer and a printed circuit board are electrically connected to each other, or a semiconductor device in which the electrodes of the respective connection parts of a plurality of semiconductor chips are electrically connected to each other In the device, the adhesive for semiconductor is used for sealing at least a part of the connection part, and the thixotropy value of the adhesive for semiconductor is not less than 1.0 and not more than 3.1, and the thixotropy value is for laminating the adhesive for semiconductor to a thickness of 400 For samples down to μm, use a shear viscosity measuring device to measure the viscosity when the frequency is continuously changed from 1 Hz to 70 Hz at a fixed temperature of 120°C, and divide the viscosity value at 7 Hz by the value at 70 Hz The value obtained from the viscosity value.

Description

Adhesive for semiconductor and method for manufacturing semiconductor device using same

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

Conventionally, when connecting a semiconductor chip (chip) and a substrate, a wire bonding method using thin metal wires such as gold wires has been widely used. On the other hand, in order to meet the requirements for high functionality, high integration, and high speed of semiconductor devices, conductive protrusions called bumps are formed on semiconductor wafers or substrates, and are directly connected between semiconductor wafers and substrates. The flip chip connection method (FC (flip chip) connection method) for connection is being promoted.

As the flip-chip connection method, there are known methods of metal bonding using solder, tin, gold, silver, copper, etc., methods of applying ultrasonic vibration to metal bonding, and methods of maintaining mechanical contact by shrinking force of resin. etc. However, from the viewpoint of the reliability of the connection part, it is generally a method of metal bonding using solder, tin, gold, silver, copper, or the like.

For example, in the connection between the semiconductor chip and the substrate, the Chip On Board (COB) type connection is popularly used in Ball Grid Array (BGA), Chip Size Package (CSP), etc. The method is also a flip-chip connection method. In addition, the flip-chip connection method is also widely used in a stacked chip (Chip On Chip, COC) type connection method (for example, refer to the following Patent Document 1).

In packages that are strongly required to be further miniaturized, thinner, and more functional, chip stacked packages, Package On Package (POP), and through-silicon vias ( Through-Silicon Via, TSV) etc. have also begun to be widely used. By disposing in a three-dimensional shape instead of a planar shape, the package can be reduced, so these technologies are often used, and are also effective in improving the performance of semiconductors, reducing noise, reducing mounting area, and saving power. As the next generation Semiconductor wiring technology has attracted attention. [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-102165

[Problem to be Solved by the Invention] In the flip-chip package that promotes high functionality, high integration, and low cost, it is required to suppress the resin bleeding width during chip mounting for the purpose of high productivity, and to mount chips at high density. Therefore, if the load at the time of crimping is reduced, the resin bleeding width is suppressed, but there is a concern that the resin may be insufficient at the corner portion of the wafer, which may cause wafer peeling or the like.

The main purpose of this disclosure is to provide an adhesive for semiconductors that can control the shape of the exuded resin during wafer mounting so that the resin exudes in a shape along the side of the wafer, thereby obtaining a semiconductor device that does not have insufficient resin during mounting. And the manufacturing method of the semiconductor device using the said adhesive agent for semiconductors. [Means to solve the problem]

One aspect of the present disclosure is [1] an adhesive for semiconductors, a semiconductor device in which electrodes at respective connection portions of a semiconductor wafer and a printed circuit board are electrically connected to each other, or electrodes at respective connection portions of a plurality of semiconductor wafers In a semiconductor device electrically connected to each other, the adhesive for semiconductor is used to seal at least a part of the connection portion, the thixotropic value of the adhesive for semiconductor is 1.0 or more and 3.1 or less, and the thixotropic value of the semiconductor adhesive is 1.0 or more and 3.1 or less. The change value is the value when the frequency is continuously changed from 1 Hz to 70 Hz when the frequency is continuously changed from 1 Hz to 70 Hz for a sample obtained by laminating the above-mentioned semiconductor adhesive to a thickness of 400 μm. Viscosity, and the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz.

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

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

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

In addition, another aspect of the present disclosure is [5] the adhesive for semiconductors according to any one of [2] to [4], wherein the (c) high molecular weight component having a weight average molecular weight of 10,000 or more The polydispersity Mw/Mn is 3 or less.

In addition, another aspect of the present disclosure is [6] the adhesive for semiconductor according to any one of [2] to [5], wherein a part or all of the materials contained in the adhesive for semiconductor can be Soluble in cyclohexanone.

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

Furthermore, another aspect of the present disclosure is [8] a method of manufacturing a semiconductor device, including: using the adhesive for semiconductors described in any one of [1] to [7], using a connecting device and passing through the The adhesive for semiconductors aligns and connects the semiconductor chip and the printed circuit board, and at the same time electrically connects the electrodes of the connecting parts of the semiconductor chip and the printed circuit board to each other, and uses the adhesive for semiconductors to bond the semiconductor chip and the printed circuit board. A step of sealing at least a part of the connecting portion; or using a connecting device to align and connect a plurality of semiconductor wafers through the adhesive for semiconductors, and at the same time electrically connect the electrodes of the connecting portions of the plurality of semiconductor wafers to each other and sealing at least a part of the connection portion with the semiconductor adhesive. [Effect of the invention]

According to the present disclosure, by controlling the thixotropic value of the semiconductor adhesive to control the shape of the resin bleeding to the outer peripheral portion of the wafer during semiconductor device mounting, the resin seeps out along the side surface of the wafer, thereby suppressing resin shortage. In addition, according to the present disclosure, a semiconductor device using such an adhesive for a semiconductor and a method for manufacturing the same can be provided.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. In addition, in the drawings, the same symbols are assigned to the same or corresponding parts, and repeated explanations are omitted. In addition, positional relationships such as up, down, left, and right are assumed to be based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown in the drawings.

In this specification, the numerical range represented by "-" shows the range which includes the numerical value described before and after "-" as a minimum value and a maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit or lower limit of the numerical range of a certain step may be combined with the upper limit or lower limit of the numerical range of another step arbitrarily. In the numerical range described in this specification, the upper limit or the lower limit of the numerical range may be replaced with the value shown in an Example. The term "A or B" may include either one of A and B, or both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid corresponding to it.

＜Adhesives for semiconductors＞ The adhesive for semiconductors of this embodiment is applied to a semiconductor device in which the electrodes of the respective connection parts of the semiconductor wafer and the printed circuit board are electrically connected to each other, or a semiconductor device in which the electrodes of the respective connection parts of a plurality of semiconductor chips are electrically connected to each other. In the semiconductor device of the present invention, it is used for sealing at least a part of the connection portion.

The thixotropy value of the adhesive agent for semiconductors of this embodiment is 1.0 or more and 3.1 or less. The thixotropic value is measured for a sample obtained by laminating the above-mentioned semiconductor adhesive to a thickness of 400 μm, using a shear viscosity measuring device under a fixed condition of a temperature of 120°C, when the frequency is continuously changed from 1 Hz to 70 Hz Viscosity, and the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz. If the thixotropic value is 3.1 or less, the adhesive agent for semiconductors can flow sufficiently even at the corner of the wafer where the shear applied during wafer mounting is the smallest, and the resin oozes out along the side surface of the wafer. Furthermore, the thixotropic value may be 1.5 or more, 2.0 or more, or 2.5 or more.

The semiconductor adhesive of this embodiment may contain (a) epoxy resin, (b) curing agent, (c) high molecular weight components with a weight average molecular weight of 10,000 or more, and preferably further contain (d) filler, (e) auxiliary flux.

((a) component: epoxy resin) Examples of the epoxy resin of component (a) include epoxy resins having two or more epoxy groups in the molecule, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, and naphthalene type epoxy resins can be used. , phenol novolac epoxy resin, cresol novolac epoxy resin, phenol aralkyl epoxy resin, biphenyl epoxy resin, triphenylmethane epoxy resin, dicyclopentadiene cyclopentadiene Oxygen resin, various multifunctional epoxy resins, etc. (a) Components may be used alone or in combination of two or more.

Based on the total solid content of the adhesive for semiconductors, the content of the component (a) is preferably from 10% by mass to 50% by mass, more preferably from 15% by mass to 45% by mass, still more preferably from 20% by mass to 40% by mass. quality%. When the content of the component (a) is 10% by mass or more, it is easy to sufficiently control the flow of the cured resin, and if it is 50% by mass or less, the cured product does not contain too much resin component, and it is easy to reduce the warpage of the package. Moreover, by making content of (a) component into the said range, it becomes easy to control the thixotropic value of the adhesive agent for semiconductors to 1.0 or more and 3.1 or less. When the resin component is small and the filler content is large, the thixotropic value tends to be small. Therefore, it is easy to reduce the thixotropic value by making content of (a) component 50 mass % or less.

((b) Component: Hardener) The adhesive agent for semiconductors of this embodiment contains (b) hardening|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 phenolic hydroxyl groups, acid anhydrides, amines, or imidazoles, it is easy to exhibit flux activity that suppresses the formation of an oxide film in the connection portion, and it is easy to improve connection reliability and insulation reliability. Each curing agent will be described below.

(b-i) Phenolic resin hardener Examples of phenolic resin-based hardeners include those having two or more phenolic hydroxyl groups in the molecule. Usable phenol novolac resins, cresol novolak resins, phenol aralkyl resins, cresol naphthol formaldehyde condensation polymers, Triphenylmethane type polyfunctional phenolic resin, various polyfunctional phenolic resins, etc. The phenolic resin-based hardener can be used alone or in combination of two or more.

From the viewpoint of excellent curability, adhesiveness, and storage stability, the equivalent ratio (phenolic hydroxyl group/epoxy group, molar ratio) of the phenolic resin-based hardener to the component (a) is preferably 0.3 to 0.3 1.5, more preferably 0.4 to 1.0, still more preferably 0.5 to 1.0. If the equivalent ratio is 0.3 or more, there is a tendency for the curability to increase and the adhesive force to increase. If it is 1.5 or less, unreacted phenolic hydroxyl groups will not remain excessively, the water absorption rate will be suppressed to a low value, and the insulation reliability will be further improved. tendency to increase.

(b-ii) Acid anhydride hardener As acid anhydride hardeners, usable: Methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bis-trimellitic anhydride Wait. The acid anhydride-based curing agents can be used alone or in combination of two or more.

From the viewpoint of excellent curability, adhesiveness, and storage stability, the equivalent ratio (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, it is 0.4-1.0, More preferably, it is 0.5-1.0. If the equivalent ratio is 0.3 or more, the hardening property tends to be improved and the adhesive force tends to be improved. If it is 1.5 or less, unreacted acid anhydride will not remain excessively, the water absorption rate will be suppressed to a low value, and the insulation reliability will be further improved. tendency.

(b-iii) Amine hardener As the amine-based curing agent, dicyandiamide, various amine compounds, and the like can be used.

From the viewpoint of excellent curability, adhesiveness, and storage stability, 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 0.3 to 1.5. Preferably, it is 0.4-1.0, More preferably, it is 0.5-1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesion tends to be improved, and when it is 1.5 or less, unreacted amine does not remain excessively, and the insulation reliability tends to be further improved.

(b-iv) imidazole hardener Examples of imidazole hardeners include: 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 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-di Amino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methanol Imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isotriazine Polycyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethyl Based imidazole, adducts of epoxy resin and imidazoles, etc. Among these, 1-cyanoethyl-2-undecylimidazole and 1-cyano-2-phenylimidazole are preferable from the viewpoint of excellent curability, storage stability, and connection reliability. , 1-cyanoethyl-2-undecylimidazolium 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-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. The imidazole-based curing agents can be used alone or in combination of two or more. In addition, it can also be used as a latent curing agent obtained by microencapsulating these.

The content of the imidazole-based curing agent is preferably from 0.1 to 20 parts by mass with respect to 100 parts by mass of the component (a), more preferably from 0.1 to 10 parts by mass. When the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and if it is 20 parts by mass or less, the adhesive composition does not harden before the metal joint is formed, and poor connection tends to be less likely to occur.

(b-v) Phosphine hardeners Examples of phosphine-based hardeners include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrakis(4-methylphenyl)borate, and tetraphenylphosphonium (4-fluorophenyl ) borate etc.

The content of the phosphine-based curing agent is preferably from 0.1 to 10 parts by mass, more preferably from 0.1 to 5 parts by mass, based on 100 parts by mass of the component (a). When the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and if it is 10 parts by mass or less, the adhesive for semiconductors does not harden before metal bonding is formed, and poor connection tends to be less likely to occur.

The phenolic resin-based hardener, acid anhydride-based hardener, and amine-based hardener can be used alone or in combination of two or more. The imidazole-based hardener and the phosphine-based hardener can be used alone, but they can also be used together with a phenolic resin-based hardener, an acid anhydride-based hardener, or an amine-based hardener.

As component (b), from the viewpoint of excellent curability, it is preferable to use a phenol resin-based curing agent and an imidazole-based curing agent in combination, to use an acid anhydride-based curing agent and an imidazole-based curing agent in combination, to use an amine-based curing agent in combination with an imidazole-based curing agent. Agent, use imidazole hardener alone. Since productivity improves when connecting in a short time, it is more preferable to use the imidazole type hardening agent excellent in rapid hardening property alone. In this case, if curing is performed in a short time, volatile components such as low-molecular components can be suppressed, so generation of voids can also be easily suppressed.

((c) component: a high molecular weight component with a weight average molecular weight of 10,000 or more) Examples of (c) high molecular weight components having a weight average molecular weight of 10,000 or more (excluding compounds corresponding to component (a)) include phenoxy resins, polyimide resins, polyamide resins, and polycarbodiimides. resin, cyanate resin, (meth)acrylic resin, polyester resin, polyethylene resin, polyether resin, polyetherimide resin, polyvinyl acetal resin, polyurethane resin, Acrylic rubber and the like, among which, phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber, and cyanate resin are preferable from the viewpoint of excellent heat resistance and film formability. 1. Polycarbodiimide resin, more preferably phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber. The component (c) may be used alone or as a mixture or copolymer of two or more.

The mass ratio of the component (c) to the component (a) is not particularly limited, and the content of the component (a) is preferably 0.01 to 5 parts by mass relative to 1 part by mass of the component (c) in order to maintain a film shape, more preferably Preferably, it is 0.05 mass part - 4 mass parts, More preferably, it is 0.1 mass part - 3 mass parts. When the content of the component (a) is 0.01 parts by mass or more, curability or adhesive force does not decrease, and when the content is 5 parts by mass or less, film formability and film formability do not decrease. Moreover, the thixotropic value can also be adjusted by the combination of (c) component and (a) component, and these mass ratios.

The weight average molecular weight of the component (c) is 10,000 or more in terms of polystyrene, and in order to independently exhibit good film formability, it is preferably 30,000 or more, more preferably 40,000 or more, and more preferably 50,000 or more. When the weight average molecular weight is 10000 or more, there is no possibility that the film formability may fall. In addition, in this specification, a weight average molecular weight means the weight average molecular weight when it measures with polystyrene conversion using high performance liquid chromatography (C-R4A by Shimadzu Corporation).

(c) The polydispersity Mw/Mn of the component is preferably 3 or less, more preferably 2.5 or less. When Mw/Mn is 3 or less, there is little variation in molecular weight and there exists a tendency for a thixotropic value to fall easily.

((d) Ingredient: Filler) As a filler of (d) component, an insulating inorganic filler etc. are mentioned. Among them, an inorganic filler having an average particle diameter of 100 nm or less is more preferable. Examples of insulating inorganic fillers include glass, silica, alumina, titanium oxide, mica, and boron nitride, among which silica, alumina, titanium oxide, and boron nitride are preferred, and more preferably Silicon dioxide, aluminum oxide, boron nitride. Whiskers may be used as the insulating inorganic filler, and examples of the whiskers 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. (d) The shape, particle size, and content of the components are not particularly limited.

The component (d) is preferably insulating from the viewpoint of better insulation reliability. It is preferable that the adhesive agent for semiconductors of this embodiment does not contain conductive metal fillers, such as a silver filler and a solder filler.

From the viewpoint of dispersibility and adhesive improvement, the component (d) is preferably a surface-treated filler. Examples of surface treatment agents include glycidyl-based (epoxy-based) compounds (excluding compounds corresponding to component (a), amine-based compounds, phenyl-based compounds, phenylamine-based compounds, (methyl) Acrylic compounds (for example, compounds having a structure represented by the following general formula (1)), vinyl compounds having a structure represented by the following general formula (2), and the like.

[R¹¹ 表示氫原子或烷基，R¹² 表示伸烷基][chemical 1]

[R ¹¹ represents a hydrogen atom or an alkyl group, R ¹² represents an alkylene group]

Examples of fillers surface-treated with a compound having a structure represented by general 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 R ¹¹ is Ethyl ethacrylic acid surface treatment filler, etc., from the viewpoint of reactivity with the resin contained in the semiconductor adhesive and the surface of the semiconductor substrate, and bond formation, it is preferable that ^R11 is not a bulky acrylic surface treatment Filler, methacrylic surface treatment filler. ^R12 is also not particularly limited, but one with a higher weight average molecular weight is preferable because it has less volatile components.

[R²¹ 、R²² 及R²³ 表示一價有機基，R²⁴ 表示伸烷基][Chem 2]

[R ²¹ , R ²² and R ²³ represent a monovalent organic group, 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 small groups such as hydrogen atoms or alkyl groups. In addition, R ²¹ , R ²² and R ²³ may be a monovalent organic group having improved vinyl reactivity. R ²⁴ is also not particularly limited, and is preferably one with a higher weight average molecular weight from the viewpoint of less volatilization and thus can easily reduce pores. In addition, R ²¹ , R ²² , R ²³ and R ²⁴ can be selected according to the ease of surface treatment.

As the surface treatment agent, silane treatment agents such as epoxy-based silanes, amino-based silanes, and (meth)acrylic-based silanes are preferable in terms of easiness of surface treatment. The surface treatment agent is preferably a glycidyl-based, phenylamine-based, or (meth)acrylic-based compound from the viewpoint of excellent dispersibility, fluidity, and adhesive force. As the surface treatment agent, from the viewpoint of excellent storage stability, phenyl-based or (meth)acrylic-based compounds are more preferable.

The average particle diameter of the component (d) is preferably at most 100 nm, more preferably at most 60 nm, from the viewpoint of improved visibility. From the viewpoint of improving the adhesive force, the component (d) is preferably an inorganic filler with an average particle diameter of 60 nm or less that has been surface-treated with (meth)acrylic silane or epoxy silane. On the other hand, the larger the average particle diameter of the component (d), the smaller the thixotropic value tends to be.

Based on the total amount of the adhesive for semiconductors, the content of the component (d) is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 75% by mass, further preferably 50% by mass to 75% by mass . When the content of the component (d) is 20% by mass or more, there is no possibility that the adhesive force may decrease or the reflow resistance may decrease. Moreover, when content of (d) component is 80 mass % or less, there is no possibility that connection reliability may fall by thickening. There is a tendency for the thixotropic value to decrease as the content of the component (d) increases.

((e) component: flux)

The adhesive for semiconductors may further contain (e) a flux exhibiting flux activity (activity to remove oxides, impurities, etc.). Examples of the flux include nitrogen-containing compounds having non-covalent electron pairs (imidazoles, amines, etc.; compounds contained in component (b) are excluded), carboxylic acids, phenols, and alcohols. Furthermore, carboxylic acids exhibit stronger flux activity than alcohols, and tend to improve connectivity.

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

Adhesives for semiconductors can also be formulated: ion capture agents, antioxidants, silane coupling agents, titanium coupling agents, leveling agents, etc. These may be used alone or in combination of two or more. What is necessary is just to adjust suitably so that the effect of each additive may be exhibited about the compounding quantity of these.

<Manufacturing method of adhesive for semiconductor>

It is preferable that the adhesive agent for semiconductors of this Embodiment is a film form (film adhesive agent) from a viewpoint of productivity improvement. The method for producing the film adhesive will be described below.

First, after adding (a) component, (b) component, (c) component, and other components as needed to an organic solvent, it dissolves or disperses by stirring mixing, kneading, etc., and prepares a resin varnish. Thereafter, on the substrate film subjected to mold release treatment, the film is coated with a blade coater, a roll coater, an applicator, a die coater, a comma coater, or the like. After applying resin varnish, the organic solvent is reduced by heating to form a film-like adhesive on the base film. Alternatively, a film-like adhesive may be formed on a wafer by spin-coating a resin varnish on a wafer or the like to form a film before reducing the organic solvent by heating, followed by solvent drying.

As the organic solvent used in the preparation of the resin varnish, it is preferable to have the characteristics that each component can be uniformly dissolved or dispersed, for example, dimethylformamide, dimethylacetamide, N-methyl- 2-Pyrrolidone, Dimethylsulfone, Diethylene Glycol Dimethyl Ether, Toluene, Benzene, Xylene, Methyl Ethyl Ketone, Tetrahydrofuran, Ethyl Cellosolve, Ethyl Cellosolve Acetate, Butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. Among these, it is preferable to use cyclohexanone from the viewpoint of film forming property, and it is preferable that a part or all of the materials contained in the adhesive agent for semiconductors is soluble in cyclohexanone. That is, it is preferable that a part or all of the materials contained in the resin varnish are cyclohexanone dissolved substances. These organic solvents can be used individually or in combination of 2 or more types. Stirring mixing and kneading at the time of preparing a resin varnish can be performed using a mixer, an attritor, a triple roll, a ball mill, a bead mill, or a homogenizer, for example.

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 examples include: polyester film, polypropylene film, polyethylene terephthalate film, polyethylene terephthalate film, Imide film, polyetherimide film, polyether naphthalate film, methylpentene film, etc. The base film is not limited to a single-layer film containing one of these films, but may be a multilayer film containing two or more films.

As conditions for volatilizing the organic solvent from the applied resin varnish, specifically, heating at 50° C. to 200° C. for 0.1 minutes to 90 minutes is preferred. As long as it does not affect the porosity after installation, viscosity adjustment, etc., it is preferable to set it as the condition that the organic solvent volatilizes to 1.5% by mass or less.

From the viewpoint of visibility, fluidity, and fillability, the thickness of the film in the film-shaped adhesive of this embodiment is preferably from 10 μm to 100 μm, more preferably from 20 μm to 50 μm.

＜Semiconductor Devices＞ The adhesive agent for semiconductors of this embodiment can be preferably used in semiconductor devices, and thus is preferred as an adhesive agent for semiconductors, and is formed by electrically connecting electrodes at the respective connecting parts of the semiconductor wafer and the printed circuit board, for example. In a semiconductor device, or a semiconductor device in which the electrodes of the connection parts of a plurality of semiconductor wafers are electrically connected to each other, it can be used particularly preferably for sealing the connection part. Hereinafter, a semiconductor device using the adhesive for a semiconductor of this embodiment will be described. The electrodes of the connection portion in the semiconductor device may be any of metal bonding between bumps and wirings and metal bonding between bumps. In a semiconductor device, for example, a flip-chip connection in which electrical connection is obtained through an adhesive for a semiconductor can be used.

1( a ) and FIG. 1( b ) are schematic cross-sectional views showing an embodiment of a semiconductor device (a COB-type connection between a semiconductor wafer and a substrate). As shown in FIG. 1( a ), the first semiconductor device 100 has: a semiconductor wafer 10 and a substrate (wiring circuit board) 20 facing each other; The connection bump 30 which connects the wiring 15 of the semiconductor wafer 10 and the board|substrate 20 mutually, and the adhesive agent 40 for semiconductors which fills the gap between the semiconductor wafer 10 and the board|substrate 20 without gap. The semiconductor chip 10 and the substrate 20 are flip-chip connected through the wiring 15 and the connection bump 30 . The wiring 15 and the connection bump 30 are sealed with the adhesive 40 for semiconductors, and are blocked from the external environment.

As shown in FIG. 1( b ), the second semiconductor device 200 has: a semiconductor wafer 10 and a substrate (wiring circuit board) 20 facing each other, and bumps 32 arranged on the surfaces of the semiconductor wafer 10 and the substrate 20 facing each other. , and the adhesive 40 for semiconductors that fills the gap between the semiconductor wafer 10 and the substrate 20 without gaps. The semiconductor wafer 10 and the substrate 20 are connected to each other through the facing bumps 32 , and are flip-chip connected. The bump 32 is sealed by the adhesive 40 for semiconductors, and is blocked from the external environment.

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

The semiconductor wafer 10 is not particularly limited, and can be used: elemental semiconductors composed of the same type of elements such as silicon and germanium; gallium. Arsenic, indium. Various semiconductors such as compound semiconductors such as phosphorus.

As the substrate 20, it is not particularly limited as long as it is a wiring circuit board, and glass epoxy resin, polyimide resin, polyester resin, ceramics, epoxy resin, and bismaleimide triazine resin can be used. On the surface of the insulating substrate as the main component, etc., the unnecessary parts of the formed metal layer are etched away to form a circuit substrate with wiring (wiring pattern); A circuit board on which wiring (wiring pattern) is formed; a circuit board on which wiring (wiring pattern) is formed by printing a conductive substance on the surface of the insulating substrate, and the like.

Connection parts such as wiring 15 and bump 32 contain gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper), nickel, tin, lead, etc. as main components. Can contain various metals.

On the surface of the wiring (wiring pattern), it may also be formed with gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. as the main components. composition of the metal layer. The metal layer may contain only a single component or multiple components. In addition, it may have a structure in which a plurality of metal layers are laminated. Copper and solder are generally used because they are cheap. Furthermore, copper and solder contain oxides, impurities, and the like, so the adhesive for semiconductors preferably has flux activity.

As the material of the conductive protrusions called bumps, gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. can be used as the main material. Components may contain only a single component or multiple components. In addition, it can also be formed as a structure in which these metals are laminated. Bumps can also be formed on semiconductor wafers or substrates. Copper and solder are generally used because they are cheap. Furthermore, copper and solder contain oxides, impurities, and the like, so the adhesive for semiconductors preferably has flux activity.

In addition, semiconductor devices (packages) as shown in Fig. 1(a), Fig. 1(b) or Fig. 2(a), Fig. 2(b) can also be stacked, and gold, silver, copper, solder (main Components such as tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. are electrically connected. For example, as seen in TSV technology, an adhesive agent can be interposed between semiconductor wafers to perform flip-chip connection or build-up, forming holes through the semiconductor wafers, and connecting to electrodes on the pattern surface.

3 is a schematic cross-sectional view showing another embodiment (semiconductor wafer stacked type (TSV)) of another embodiment of the semiconductor device. 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 connecting the semiconductor chip 10 and the interposer. 50 flip-chip connections. The gap between the semiconductor wafer 10 and the interposer 50 is filled with the adhesive 40 for semiconductor without any gap. On the surface of the semiconductor wafer 10 opposite to the interposer 50 , the semiconductor wafer 10 is repeatedly laminated via the wiring 15 , the connection bump 30 , and the adhesive 40 for semiconductors. The wirings 15 on the front and back pattern surfaces of the semiconductor wafer 10 are connected to each other by the through electrodes 34 filled in the holes penetrating the inside of the semiconductor wafer 10 . Note that copper, aluminum, or the like can be used as the material of the penetration electrode 34 .

With this TSV technology, signals can also be obtained from the backside of the semiconductor chip, which is not normally used. Furthermore, since the through electrodes 34 vertically penetrate through the semiconductor wafers 10 , the distance between the opposing semiconductor wafers 10 or between the semiconductor wafers 10 and the interposer 50 can be shortened to realize flexible connection. The semiconductor adhesive of this embodiment can be preferably used as a sealing material between opposing semiconductor wafers 10 or between the semiconductor wafer 10 and the interposer 50 in such TSV technology.

<Manufacturing method of semiconductor device> The manufacturing method of the semiconductor device of this embodiment connects a semiconductor chip and a printed circuit board, or a some semiconductor chip mutually using the adhesive agent for semiconductors of this embodiment. The method for manufacturing a semiconductor device according to the present embodiment includes, for example, the steps of connecting the semiconductor wafer and the printed circuit board to each other through an adhesive, and electrically connecting the connection portions of the semiconductor chip and the printed circuit board to each other to obtain a semiconductor device. Alternatively, while connecting a plurality of semiconductor wafers to each other via an adhesive, electrically connect the connection portions of the plurality of semiconductor wafers to each other to obtain a semiconductor device.

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

As an example of a method of manufacturing a semiconductor device according to this embodiment, a method of manufacturing a sixth semiconductor device 600 shown in FIG. 4 will be described. In the sixth semiconductor device 600 , a substrate (such as a glass epoxy substrate) 60 having wiring (copper wiring) 15 , and a substrate having wiring (such as a copper pillar, copper post) 15 semiconductor wafers 10 are connected to each other. 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 . On the surface of the substrate 60 on which the wiring 15 is formed, the solder resist 70 is arranged other than the formation position of the connection bump 30 .

In the method of manufacturing the sixth semiconductor device 600 , first, the adhesive (film adhesive or the like) 40 for semiconductors is attached to the substrate 60 on which the solder resist 70 is formed. Attachment can be performed by heat pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the adhesive agent 40 for semiconductors can be suitably set according to the size of the semiconductor wafer 10 or the board|substrate 60, a bump height, etc. FIG. The semiconductor adhesive 40 can be pasted on the semiconductor wafer 10, or the semiconductor adhesive 40 can be pasted on the semiconductor wafer and then cut and divided into individual semiconductor wafers 10, thereby making a semiconductor adhesive 40 semiconductor wafer 10. In this case, if it is an adhesive for semiconductors with high light transmittance, the visibility can be ensured even if the alignment mark is covered, so it is attached not only on the semiconductor wafer (semiconductor wafer) but also on the substrate. The attachment range is not limited, and the operability is excellent.

After the semiconductor adhesive 40 is attached to the substrate 60 or the semiconductor wafer 10 , the connecting bumps 30 on the wiring 15 of the semiconductor wafer 10 and the wiring 15 of the substrate 60 are aligned using a connecting device such as a flip chip bonder. Then, the semiconductor wafer 10 and the substrate 60 are pressed while being heated at a temperature higher than the melting point of the connection bump 30 (when solder is used for the connection portion, it is preferable to apply a temperature of 240° C. or higher to the solder portion), thereby The semiconductor wafer 10 is connected to the substrate 60 , and the gap between the semiconductor wafer 10 and the substrate 60 is sealed and filled with the semiconductor adhesive 40 . The connection load depends on the number of bumps, but it should be set in consideration of absorbing the height unevenness of the bumps and controlling the amount of deformation of the bumps. From the viewpoint of improving productivity, the connection time is preferably short. It is preferable to melt the solder to remove the oxide film, surface impurities, etc., and form a metal joint at the connection portion.

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

It is also possible to perform temporary fixation after alignment, and heat treatment in a reflow furnace to melt the solder bumps and connect the semiconductor chip to the substrate, thereby manufacturing a semiconductor device. Temporary fixing does not necessarily require the formation of metal joints, so compared with the above-mentioned permanent crimping, it can provide advantages such as lower load, shorter time, and lower temperature, improved productivity, and prevention of deterioration of the connection portion. After connecting the semiconductor wafer and the substrate, heat treatment may be performed in an oven or the like to harden the adhesive. The heating temperature is a temperature at which the adhesive is cured, preferably substantially 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 the adhesive. [Example]

Hereinafter, an Example is given and this indication is demonstrated further concretely. 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 ・Multifunctional solid epoxy resin containing a trisphenolmethane skeleton (manufactured by Mitsubishi Chemical Corporation, trade name "EP1032H60", hereinafter referred to as "EP1032") ・Epoxy resin containing naphthalene skeleton (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) Hardener ・2,4-Diamino-6-[2'-methylimidazole-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Chemical Industry Co., Ltd., commercial product name "2MAOK-PW", hereinafter referred to as "2MAOK")

(c) High molecular weight components with a weight average molecular weight of 10,000 or more ・Acrylic resin (manufactured by Kuraray Co., Ltd., trade name "Kuraray LA4285", Mw/Mn=1.28, weight average molecular weight Mw: 80000)

(d) filler Inorganic filler ・Epoxy surface-treated nano silica filler (manufactured by Admatechs Co., Ltd., trade name "50nmSE-AH1", average particle size: about 50 nm, hereinafter referred to as "SE nano silica 」) ・Inorganic silica filler (manufactured by Admatechs Co., Ltd., trade name "SE2050", average particle size: 0.5 μm, hereinafter referred to as "SE2050") ・Inorganic silica filler (manufactured by Admatechs Co., Ltd., trade name "SE2050SEJ", average particle size: 0.5 μm, hereinafter referred to as "SE2050SEJ")

(e) Flux ・Glutaric acid (manufactured by Sigma Aldrich Japan Co., Ltd., melting point: about 97°C)

＜Production of film adhesive＞ (Example 1) Put 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 hardener "2MAOK", and 0.45 g of glutaric acid , Inorganic filler "SE nano silica" 35.3 g, acrylic resin "LA4285" 2.0 g, and cyclohexanone (an amount such that the solid content in the resin varnish becomes 47% by mass), add the same mass as the solid content Beads with a diameter of 1.0 mm were stirred for 30 minutes using a bead mill (manufactured by Fritsch Co., Ltd., planetary pulverizer P-7). Thereafter, beads used for stirring were removed by filtration to obtain a resin varnish.

The obtained resin varnish was coated on a substrate film (manufactured by Teijin DuPont Film Co., Ltd., trade name "Purex (Purex) A54") using a small precision coating device (manufactured by Yashii Seiki Co., Ltd.) , the applied resin varnish was dried (100° C./5 minutes) in a clean oven (manufactured by ESPEC Co., Ltd.) to obtain a film-like adhesive. Manufactured so that the thickness becomes 0.02 mm.

(Example 2) Except having increased epoxy resin "HP4032D" to 1.5 g, and decreased epoxy resin "YL983" to 0.75 g, it carried out similarly to Example 1, and produced the film-form adhesive agent.

(comparative example 1) Do not mix the epoxy resin "YL7175" and "HP4032D", and add 2.3 g of inorganic silica filler (manufactured by Admatechs Co., Ltd., trade name "SE2050", average particle size: 0.5 μm), except Except that, it carried out similarly to Example 1, and produced the film-form adhesive agent.

(comparative example 2) Add 3.3 g of inorganic silica filler (manufactured by Admatechs Co., Ltd., trade name "SE2050SEJ", average particle size: 0.5 μm) to reduce "SE nanosilica" to 27.9 g, and Except having reduced "LA4285" to 0.5 g, it carried out similarly to Example 1, and produced the film-form adhesive agent.

In Table 1, the formulation of Example 1-Example 2 and Comparative Example 1-Comparative Example 2 is collectively shown.

＜Evaluation＞ The evaluation methods of the film adhesives obtained in Examples and Comparative Examples are shown below.

(1) Preparation of samples for thixotropic value measurement Using a desktop laminator (manufactured by Lami Corporation, trade name "HOTDOG GK-13DX"), laminate (laminate) multiple sheets of the prepared film-like adhesive to a total thickness of 0.4 mm (400 μm), and cut out a size of 7.3 mm in length and 7.3 mm in width to obtain a measurement sample.

(2) Determination of thixotropic value The obtained measurement sample was measured with a shear viscosity measuring device (manufactured by TA Instruments Japan Co., Ltd., trade name "ARES") under a fixed condition of a temperature of 120° C. The viscosity is continuously changed from 0.1 Hz to 70 Hz in seconds, and the value obtained by dividing the viscosity value at 7 Hz by the viscosity value at 70 Hz is set as the thixotropic value.

(3) Manufacturing method of semiconductor device The produced film adhesive was cut out (7.3 mm in length, 7.3 mm in width, and 0.045 mm in thickness), and attached to a semiconductor wafer with solder bumps (wafer size: 7.3 mm in length, 7.3 mm in width, and 0.15 mm in thickness mm, bump height: the total of copper pillar + solder is about 45 μm, the number of bumps is 328, and the pitch is 80 μm). Next, using a flip chip bonder FCB3 (manufactured by Panasonic Co., Ltd.), the semiconductor wafer with solder bumps attached with a film adhesive is mounted on a glass epoxy substrate (thickness of the glass epoxy substrate: 420 μm, copper wiring thickness: 9 μm) (mounting conditions: crimp temperature 350°C/5 seconds/0.5 MPa), the same semiconductor device as in Fig. 4 was obtained. Set the platform temperature to 80 °C.

(4) Evaluation method of coverage Using a microscope (manufactured by Keyence Co., Ltd.), the semiconductor device obtained by the above (3) method of manufacturing a semiconductor device was observed from above the upper wafer to measure The width of resin exudation from the end of the wafer. Regarding the bleed width, the bleed width W ₁ (unit: μm) of the resin from the center of one side of the wafer and the bleed width of the resin from a position 0.2 mm from the center side from one end (corner of the wafer) of the one side were measured. W ₂ (unit: μm), and calculate the ratio (W ₂ /W ₁ ) of the two. Furthermore, _W2 is the smaller of the width of the resin oozing from the center side of the wafer at a distance of 0.2 mm from one end of the one side and the width of the resin oozing from the center side of the other end at 0.2 mm. value. The ratio (W ₂ /W ₁ ) was measured for all four sides of the wafer, and the average value thereof was obtained as "coverage".

Coverage is an index showing whether the adhesive resin has penetrated into the corner of the wafer in the semiconductor device. Since it is preferable that there is no difference in the bleeding width between the corners of the semiconductor device and the center of the side, the closer the coverage is to 1, the better.

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

[Table 1]

According to the evaluation results in Table 1, the coverage of Example 1 and Example 2 with thixotropic values of 3.1 or less exceeded 0.4, and the coverage of Comparative Examples 1 and 2 with large thixotropic values exceeding 3.1 was less than 0.4. From the above, it was confirmed that the film-form adhesive agent for semiconductors of the present disclosure having a low thixotropic value has high coverage.

10: Semiconductor wafer

15: Wiring

20, 60: Substrate

30: Connection bump

32: Bump

34: Through electrode

40: Adhesives for semiconductors

50: Interposer

70: Solder resist

100: The first semiconductor device

200: Second semiconductor device

300: The third semiconductor device

400: The fourth semiconductor device

500: fifth semiconductor device

600: The sixth semiconductor device

1( a ) and FIG. 1( b ) are schematic cross-sectional views showing an embodiment of the semiconductor device of the present disclosure. 2( a ) and FIG. 2( b ) are schematic cross-sectional views showing another embodiment of the semiconductor device of the present disclosure. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure. FIG. 4 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure.

10‧‧‧semiconductor chip

15‧‧‧Wiring

20‧‧‧substrate

30‧‧‧connection bump

40‧‧‧Adhesive for semiconductor

100‧‧‧first semiconductor device

Claims (7)

An adhesive for semiconductors, wherein the adhesive for semiconductors is used in a semiconductor device in which the electrodes of the connection parts of a semiconductor wafer and a printed circuit board are electrically connected to each other, or the electrodes of the connection parts of a plurality of semiconductor chips are electrically connected to each other. For sealing at least a part of the connection part in a semiconductor device formed by permanent connection, the adhesive for semiconductor contains (a) epoxy resin, (b) hardener, and (c) weight average molecular weight of 40000 or more The thixotropic value of the semiconductor adhesive is 1.0 to 3.1. The thixotropic value is for a sample obtained by laminating the semiconductor adhesive to a thickness of 400 μm, using the shear viscosity The measuring device measures the viscosity when the frequency is continuously changed from 1 Hz to 70 Hz under the fixed condition of temperature 120°C, and divides the viscosity value at 7 Hz by the viscosity value at 70 Hz. The adhesive for semiconductors described in item 1 of the patent claims further contains (d) a filler. The adhesive for semiconductors as described in claim 1 or claim 2 further contains (e) a flux. The adhesive for semiconductors as described in claim 1 or claim 2, wherein (c) the polydispersity Mw/Mn of the high molecular weight component having a weight average molecular weight of 40,000 or more is 3 or less. The adhesive for semiconductors described in Claim 1 or Claim 2 of the patent application, wherein a part or all of the materials contained in the adhesive for semiconductors is soluble in cyclohexanone. The adhesive for semiconductors described in claim 1 or claim 2 is in the form of a film. A method of manufacturing a semiconductor device, comprising: using the adhesive for semiconductors described in any one of the first to sixth items of the scope of the patent application, using a connecting device to connect the semiconductor wafer and the wiring circuit through the adhesive for semiconductors a step of electrically connecting the electrodes of the connecting parts of the semiconductor wafer and the printed circuit board to each other while the substrates are aligned and connected to each other, and sealing at least a part of the connecting parts with the adhesive for semiconductor; or A plurality of semiconductor wafers are aligned and connected to each other through the adhesive for semiconductors by using a connecting device, and at the same time, the electrodes of the connection parts of the plurality of semiconductor wafers are electrically connected to each other, and the adhesive for semiconductors is used to The step of sealing at least a portion of the connecting portion.

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