JP2012131852A - Urethane resin composition, cured product, and optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane resin composition that is excellent in compatibility between a polyol component and an isocyanate component and can obtain a uniform cured product having a high glass transition temperature.SOLUTION: The urethane resin composition is a two-liquid type urethane resin composition comprising a liquid A containing a polyol component and a liquid B containing a polyisocyanate component. The polyol component contains a trifunctional or higher polyol compound having a hydroxyl value of 550-675 mgKOH/g. The polyisocyanate component contains an alicyclic polyisocyanate and a prepolymer having a remaining isocyanate group of the alicyclic polyisocyanate, and has an isocyanate group content of 26.0-30.0 mass%.

Description

  The present invention relates to a urethane resin composition, a cured body, and an optical semiconductor device using the cured body.

  In the optical semiconductor device, the sealing member is molded by curing the resin composition in order to protect the optical semiconductor element. The resin composition is usually cured and molded by a potting method in which the resin composition is cast in a case or in a lead frame cavity, or in a liquid transfer molding in which the resin composition is filled in a cavity formed by a molding die in a molding apparatus. Or compression molding method. At this time, a hard transparent resin is required in a structure in which the shape of the optical semiconductor device is formed only by the transparent resin and the lead frame, or in a structure in which the lens shape is formed by the transparent resin. Moreover, in order to ensure various mounting reliability, it is preferable that the glass transition temperature of the cured body is high. In order to obtain a hardened body having a high glass transition temperature, it is common to set the crosslink density high.

  On the other hand, the polyurethane resin obtained by reaction of a polyisocyanate component and a polyisocyanate component can obtain a cured product having various physical properties by selecting various structures for the polyol and isocyanate. In order to obtain a high crosslinking density even in a urethane resin system, it is effective to contain a short-chain polyfunctional polyol compound in the polyol component. For example, Patent Document 1 discloses a urethane resin composition comprising a short-chain polyfunctional polyol and an alicyclic isocyanate as a hard urethane resin having a high glass transition temperature.

JP 2001-278951 A

  However, since a short-chain polyfunctional polyol has a high polarity, it generally tends to have poor compatibility with an isocyanate component. In addition, since aliphatic and alicyclic isocyanate compounds have low polarity, they tend to have poor compatibility with polyols. For this reason, in the conventional urethane resin composition, although a hardened body having a high glass transition temperature can be obtained, the uniformity of the cured body tends to be inferior, and both of them are not necessarily maintained at a high level.

  The present invention has been made in view of the above circumstances, and provides a urethane resin composition that is excellent in compatibility between a polyol component and an isocyanate component, and that can obtain a cured body having a uniform and high glass transition temperature. Objective.

  The present invention is a two-component urethane resin composition comprising a liquid A containing a polyol component and a liquid B containing a polyisocyanate component, wherein the polyol component has a trifunctionality having a hydroxyl value of 550 to 675 mgKOH / g. The above-mentioned polyol compound is contained, the polyisocyanate component contains an alicyclic polyisocyanate and an isocyanate group residual prepolymer of the alicyclic polyisocyanate, and the isocyanate group content is 26.0 to 30.0% by mass. A two-component urethane resin composition is provided.

  Such a urethane resin composition is sufficiently excellent in compatibility between the polyol component and the polyisocyanate component, so that a uniform cured body can be formed, and the glass transition temperature of the cured body is improved because the crosslink density is increased. I can do it. The reason why the urethane resin composition of the present invention exhibits such an effect is not necessarily clear, but the present inventors consider as follows. That is, by using a polyol compound having a hydroxyl value set in a predetermined range and an isocyanate component having an isocyanate group content set in a predetermined range, the polarity of the polyol component and the polyisocyanate component can be made closer, It is considered that the compatibility of both components is increased, the crosslinking density is high, and a uniform cured product can be obtained without lowering the glass transition temperature.

  Moreover, from the viewpoint that the glass transition temperature of the cured product can be further increased, the polyol compound is preferably a compound obtained by adding 2 to 3 moles of propylene oxide or ethylene oxide to 1 mole of trimethylolpropane. The formula isocyanate is preferably isophorone diisocyanate.

  Furthermore, in this invention, in order to improve the sclerosis | hardenability of a urethane resin composition, the said B liquid can further contain the zinc stearate whose bulk density is 0.12 g / mL or less.

  The present invention also includes a liquid A containing a polyol component containing a trifunctional or higher functional polyol compound having a hydroxyl value of 550 to 675 mgKOH / g, an alicyclic polyisocyanate, and an isocyanate group remaining prepolymer of the alicyclic polyisocyanate. A urethane resin composition comprising a polymer and containing a polyisocyanate component having an isocyanate group content of 26.0 to 30.0% by mass is cured by mixing the A liquid and the B liquid. A cured product obtained as described above is provided.

  Further, when the liquid A or the liquid B further contains an inorganic filler, the thermal expansion coefficient of the cured body is brought close to the thermal expansion coefficient of the lead frame, and peeling from the lead frame occurs in a heat resistance test or a temperature cycle test. Can be difficult.

  The present invention further provides an optical semiconductor device comprising a sealing member made of a cured product of the urethane resin composition. Such an optical semiconductor device has high optical transparency and uniformity of the cured body, and is excellent in optical characteristics such as light-resistant coloring and mechanical characteristics.

  ADVANTAGE OF THE INVENTION According to this invention, the urethane resin composition which is excellent in the compatibility of a polyol component and an isocyanate component, and can obtain the hardening body which is uniform and has a high glass transition temperature can be provided.

It is sectional drawing which shows one Embodiment of an optical semiconductor device.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  The urethane resin composition of the present embodiment comprises a liquid A containing a polyol component and a liquid B containing a polyisocyanate component, and the polyol component is a trifunctional or higher functional polyol compound having a hydroxyl value of 550 to 675 mgKOH / g. The polyisocyanate component contains an alicyclic polyisocyanate and an isocyanate group-remaining prepolymer of the alicyclic polyisocyanate, and the isocyanate group content is 26.0 to 30.0% by mass. It is a resin composition.

(Polyol component)
The polyol component which concerns on this invention is a component which consists of a compound (polyol) which has 3 or more alcoholic hydroxyl groups, and contains the trifunctional or more functional polyol compound whose hydroxyl value is 550-675 mgKOH / g.

  By selecting a polyol compound having a hydroxyl value in such a range, it is possible to obtain a cured product that is excellent in compatibility with the isocyanate component, is uniform, and has a high glass transition temperature. When the hydroxyl value of the polyol compound is larger than 675 mgKOH / g, the compatibility with the polyisocyanate component tends to be reduced. When the hydroxyl value is smaller than 550 mgKOH / g, the compatibility with the polyisocyanate component is obtained, but the glass transition temperature of the cured product is obtained. (Hereinafter referred to as “Tg”) tends to decrease.

  The hydroxyl value of the polyol compound is determined by adding the polyol compound to a pyridine solution containing acetic anhydride as an acetylating reagent, acetylating the hydroxyl group, then decomposing excess acetylating reagent with water, and It can be determined by titrating with potassium oxide.

  Here, in this specification, “excellent compatibility” means that a transparent and uniform resin composition is obtained when a polyol component and a polyisocyanate component are mixed at room temperature. The “cured body having a high glass transition temperature” means a cured body having a Tg of 100 ° C. or higher.

  As the polyol compound, for example, aliphatic polyol, alicyclic polyol, polyether polyol, polycarbonate polyol, polyester polyol, polycaprolactone polyol, and acrylic resin polyol can be used. From the viewpoint of increasing the Tg of the cured product of the urethane resin composition, the polyol compound is preferably an aliphatic polyol having a short chain length, and specifically, propylene oxide or ethylene oxide per 1 mol of trimethylolpropane. It is preferable that it is a compound which added 2-3 mol.

  Further, while trimethylolpropane is solid, a compound obtained by adding propylene oxide or ethylene oxide to trimethylolpropane is liquid and easy to handle. Furthermore, in the case of a compound obtained by adding propylene oxide to trimethylolpropane, the Tg of the cured product can be further increased as compared with a compound obtained by adding ethylene oxide due to steric hindrance of the methyl group.

  When an addition reaction of 2 or 3 moles of propylene oxide or ethylene oxide is performed on 1 mole of trimethylolpropane, 1 mole of the starting material trimethylolpropane, propylene oxide or ethylene oxide is added to the reaction product. A mixture of a plurality of polyol compounds such as a product, a 2 mol addition product, a 3 mol addition product, and a 4 mol addition product is obtained. The polyol compound may be a mixture thereof, and in this case, the hydroxyl value is a value calculated from the mixture.

  The polyol compound may be used alone, but other polyols can be used in combination in order to adjust the crosslinking density and viscosity. In that case, the polyol compound having a hydroxyl value of 550 to 675 mgKOH / g is preferably 80% by mass or more based on the total amount of the polyol component. By setting it as such a range, even when several types of polyols are used in combination, it is possible to prevent non-uniformity of the cured product caused by the difference in reactivity between the polyols.

  The polyol component may contain a hydroxyl group residual prepolymer. By including the hydroxyl group residual prepolymer in the polyol component, the compatibility between the polyol component and the polyisocyanate component can be further improved. The hydroxyl group-remaining prepolymer includes the polyol and a polyisocyanate described later (preferably a polyisocyanate having an alicyclic group described later) such that the hydroxyl group in the polyol is excessive with respect to the isocyanate group in the polyisocyanate. It is obtained by reacting. When the hydroxyl group equivalent in the polyol is X and the ratio when the isocyanate group equivalent in the polyisocyanate is Y is X / Y, the hydroxyl group-retaining prepolymer has a polyol and a poly It is preferably obtained by mixing and reacting with isocyanate. When X / Y takes a value of 3 or more, an increase in the molecular weight of the hydroxyl group-retaining prepolymer can be suppressed, and the viscosity can be easily handled. When X / Y takes a value of 20 or less, the effect of the prepolymer tends to be obtained effectively. The synthesis of the hydroxyl group-retaining prepolymer can be shortened by adding a catalyst, but it is preferable to carry out a reaction at room temperature or without heating in order to avoid coloring the polymer.

(Polyisocyanate component)
The polyisocyanate component according to the present invention is a component composed of a compound having two or more isocyanate groups (polyisocyanate) and contains an alicyclic polyisocyanate and a prepolymer in which the isocyanate group of the alicyclic polyisocyanate remains. The isocyanate group content is 26.0 to 30.0% by mass.

  Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate, 4,4′-methylenebis- (cyclohexyl isocyanate), 1,3-bis- (isocyanatomethyl) cyclohexane or norbornene diisocyanate (2,5- (2,6 ) -Bis-isocyanatomethyl [2,2,1] heptane), with isophorone diisocyanate being preferred.

  The isocyanate group-remaining prepolymer is obtained by reacting the alicyclic polyisocyanate and the polyol so that the isocyanate group in the polyisocyanate is excessive with respect to the hydroxyl group in the polyol. The isocyanate group residual prepolymer is preferably obtained by mixing and reacting a polyol and a polyisocyanate so that the above-mentioned X / Y is 0.05 to 0.3. When X / Y takes a value of 0.05 or more, the effect of the prepolymer tends to be obtained effectively. When X / Y takes a value of 0.3 or less, it is possible to suppress an increase in the molecular weight of the isocyanate group-remaining prepolymer and maintain a viscosity that is easy to handle. The synthesis of the isocyanate group-remaining prepolymer can be shortened by adding a catalyst. However, in order to avoid coloration of the polymer, it is preferable to carry out the reaction at room temperature or without heating.

  Since the polyisocyanate component contains the isocyanate group residual prepolymer together with the alicyclic polyisocyanate, the polarity difference from the polyol component can be reduced, so that it has excellent compatibility with the polyol component and is uniform and has a high glass transition temperature. The body can be obtained. In particular, when an isophorone diisocyanate having an isocyanate group bonded to a primary carbon and an isocyanate group bonded to a secondary carbon is used as the alicyclic polyisocyanate, the balance between rigidity and flexibility is excellent, and the glass transition temperature is low. A higher cured body can be obtained.

  The polyol compound used for the synthesis of the isocyanate group residual prepolymer is not particularly limited, but the same polyol compound as the polyol component is preferably used from the viewpoint of improving the compatibility with the above-described polyol component.

  When the polyisocyanate and the polyol are reacted, a raw material polyisocyanate and a mixture of a plurality of reaction products are obtained in the reaction product. More specifically, when a diisocyanate compound and a trifunctional polyol compound such as trimethylolpropane are reacted at a molar ratio in which the diisocyanate compound is excessive, the diisocyanate compound is 1 mol and 2 mol with respect to 1 mol of the polyol compound. It becomes a mixture of the compound reacted for 3 mol and the raw diisocyanate compound. The isocyanate group remaining prepolymer may be a mixture thereof.

  The isocyanate component is a mixture of an alicyclic polyisocyanate and an isocyanate group residual prepolymer, and the isocyanate group content means the isocyanate content of this mixture. The isocyanate content of the polyisocyanate component can be determined by dissolving the polyisocyanate component in methyl ethyl ketone, adding di-n-bitylamine, and back titrating with a hydrochloric acid solution using a bromophenol blue solution as an indicator.

  The isocyanate content of the polyisocyanate component is 26.0 to 30.0%, preferably 27.0 to 30.0%, and more preferably 28.0 to 30.0%. If the isocyanate content of the polyisocyanate component is greater than 30.0%, the polarity difference from the polyol component increases, so the compatibility tends to decrease. If it is less than 26.0%, the viscosity of the polyisocyanate component increases. It becomes difficult to mix with the polyol component.

  These isocyanate components can be used in combination with other polyisocyanate compounds in order to adjust the crosslinking density and viscosity. In that case, the mixture of the alicyclic polyisocyanate and the isocyanate group residual prepolymer is preferably 80% by mass or more based on the total amount of the isocyanate component. By setting in this way, it is possible to prevent non-uniformity of the cured product caused by a difference in reactivity between isocyanates when various isocyanates are used in combination.

  As the isocyanate that can be used in combination, in addition to the polyisocyanate compound described above, an isocyanurate type, biuret type, or adduct type polyisocyanate made from polyisocyanate may be used. The isocyanurate type polyisocyanate used as a raw material is preferable. By using such polyisocyanate, the glass transition temperature of the obtained cured product can be improved.

(Curing catalyst)
The B liquid which concerns on this embodiment can further contain a curing catalyst. Curing catalysts include organometallics such as zinc, zirconium or aluminum, tins such as dibutyltin laurate, DBU (1,8-diazabicyclo [5,4,0] undecan-7-ene) phenol salts, octyl Catalysts such as acid salts, amines, and imidazoles can be used. Among these, zinc stearate is preferable because it is excellent in heat resistant colorability and viscosity stability at room temperature of the urethane resin composition. From the viewpoint of the transparency of the cured product, it is preferable to use zinc stearate having a bulk density of 0.12 g / mL or less as the curing catalyst.

  The content of the curing catalyst is preferably 0.001 to 1% by mass and more preferably 0.002 to 0.1% by mass with respect to the total amount of the urethane resin composition. When the content of the curing catalyst is 0.001% by mass or more, an effect of promoting the curing tends to appear, and when it is 1% by mass or less, the cloudiness of the cured product tends to be suppressed. By adding a curing catalyst, the curability of the urethane resin composition can be increased.

(Inorganic filler)
The liquid A or the liquid B according to this embodiment may further include an inorganic filler. The inorganic filler is preferably silica in order to maintain the light transmittance of the cured product, and it is preferable to use a mixture of silica powders having different particle diameters in order to densely fill the urethane resin composition. By including an inorganic filler in the urethane resin composition, the thermal expansion coefficient of the cured body can be brought close to the thermal expansion coefficient of the lead frame of the optical semiconductor device. , Cracks in the cured body are less likely to occur.

(Other materials)
The A liquid or the B liquid according to this embodiment is a mold release agent, an adhesion-imparting agent, an antioxidant, a light stabilizer, an ultraviolet absorber, an organic filler, a polymerization inhibitor, a coupling agent, etc. May be included. Further, from the viewpoint of moldability, a plasticizer, an antistatic agent, a flame retardant, and the like may be included.

(Release agent)
When molding a urethane resin composition to obtain a cured product, various release agents can be contained in the A liquid and / or the B liquid from the viewpoint of improving the releasability from the molding die. As the release agent, one type of fatty acid type release agent or silicone type release agent can be used alone, or two or more types can be used in combination.

Examples of the fatty acid release agent include saturated fatty acids represented by the following general formula (1).
R ¹ —COOH (1)

In the formula, R ¹ represents a linear or branched hydrocarbon group having 7 to 28 carbon atoms.

Examples of the saturated fatty acid include caprylic acid, pelargonic acid, lauric acid, mythyric acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, isostearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid and montanic acid. Can be mentioned. In general formula (1), the carbon number of R ¹ is usually 7 to 28, preferably 10 to 22, and more preferably 14 to 18. Among these, isostearic acid having 17 carbon atoms is particularly preferable because it is liquid and can adjust the viscosity of the urethane resin composition.

  Various silicones can be used as the silicone release agent.

  The content of the release agent is preferably 0.01 to 5.0% by mass with respect to the total amount of the polyol component and the polyisocyanate component. When the content of the release agent is 0.01% by mass or more, there is a tendency to be excellent in releasability from the molding die, and when it is 5.0% by mass or less, the heat resistance such as the glass transition temperature of the cured product is high. It tends to suppress the decrease.

(Adhesiveness imparting agent)
It is preferable to add a compound having a thiol group as an adhesiveness imparting agent to the urethane resin composition in order to obtain adhesion to the silver plating or palladium plating of the lead frame. The compound having a thiol group is preferably a thiol group-containing silane coupling agent such as γ-mercaptopropyltrimethoxysilane or a compound having two or more thiol groups (hereinafter referred to as polythiol). A compound bonded to a primary carbon, a compound having a thiol group bonded to a secondary carbon, one or more thiol groups bonded to a primary carbon, and one or more thiol groups bonded to a secondary carbon Examples thereof include compounds bonded to carbon.

  Examples of the compound in which the thiol group is bonded to the primary carbon include thiol groups such as tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, trimethylolpropane tris- (3-mercaptopropionate), etc. A compound having four thiol groups such as pentaerythritol tetrakis-3-mercaptopropionate; a compound having six thiol groups such as dipentaerythritol hexa-3-mercaptopropionate, etc. .

  In addition, as a compound in which the thiol group is bonded to the secondary carbon, a compound having two thiol groups such as 1,4-bis- (3-mercaptobutyloxy) butane; 1,3,5-tris- Compound having three thiol groups such as (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione; pentaerythritol tetrakis-3-mercaptobutyrate And compounds having four thiol groups such as

  It is preferable that content of a thiol compound is 0.01-2.0 mass% with respect to whole quantity of the said polyol component and the said isocyanate component. When the content of the thiol compound is 0.01% by mass or more, there is a tendency to improve the adhesion with the silver plating, and when it is 2.0% by mass or less, the heat resistance such as the glass transition temperature of the cured product. Tend to be able to hold. Moreover, when the above-mentioned mold release agent is included in the urethane resin composition, the adhesion between the cured product and the silver plating can be improved without impairing the mold release property with the molding die.

  Since the thiol compound reacts with the isocyanate component, it is preferably added to the A component side of the polyol component.

(Antioxidant)
Examples of the antioxidant include hindered phenol-based, sulfur-based and phosphorus-based antioxidants. Among these, it is particularly preferable to use one or more hindered phenolic and sulfur antioxidants alone or in combination. Specifically, as the oxidizing agent, [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyl} -1,1-dimethylethyl] -2,4,8,10- And tetraoxaspiro [5,5] undecane.

  It is preferable that content of antioxidant is 0.05-5 mass% with respect to the whole quantity of a polyol component and a polyisocyanate component, and it is more preferable that it is 0.05-0.3 mass%. When the content of the antioxidant is 0.05% by mass or more, the effect as an antioxidant tends to be effectively obtained, and when the content is 5% by mass or less, the surface of the cured product when dissolved or cured. There is a tendency that problems such as precipitation on the surface are less likely to occur. By adding an antioxidant, it is possible to suppress deterioration of the cured body due to heat or light.

(Coupling agent)
Examples of the coupling agent include silane coupling agents having an epoxy group, a ureido group, and the like. It is preferable that content of the coupling agent in a urethane resin composition is 0.1-2 mass% with respect to the whole quantity of a polyol component and a polyisocyanate component. By including the coupling agent in the urethane resin composition, the adhesion between the cured body and the lead frame silver plating, light emitting element, wire, inorganic filler and the like is improved.

(Hardened body)
The cured body according to the present embodiment can be produced by mixing the liquid A containing the polyol component and the liquid B containing the polyisocyanate component, and heating and reacting them. The mixing ratio of the polyol component and the polyisocyanate component, and the mixing ratio of the hydroxyl group remaining prepolymer and the isocyanate group remaining prepolymer are (total hydroxyl group equivalent of polyol and hydroxyl group remaining prepolymer) / (poly The total isocyanate group equivalent amount of isocyanate and isocyanate group remaining prepolymer) is preferably 0.7 to 1.3, more preferably 0.8 to 1.1. When the mixing ratio is in the range of 0.7 to 1.3, the cured body tends to improve heat resistance, optical characteristics, and mechanical characteristics. When mix | blending an inorganic filler, after mixing A liquid and B liquid, you may add to a urethane resin composition.

  The urethane resin composition of the present invention can also be used as a one-component adhesive that is stored frozen after two-component mixing, in addition to being able to be used as a two-component adhesive. The adhesive is used for adhesion between the adherend and the adherend, but is suitable for an adhesive for optical use because of high uniformity of the cured body and high Tg.

(Optical semiconductor device)
The optical semiconductor device can be manufactured by sealing the optical semiconductor element by liquid transfer molding or compression molding the urethane resin composition obtained as described above. At this time, the urethane resin composition preferably has a gelation time at the molding temperature of 25 to 200 seconds. By setting the gelation time within this range, it is possible to manufacture under almost the same molding conditions as in the conventional solid transfer molding. When the gelation time is shorter than 25 seconds, the molten urethane resin composition is cured before sufficiently filling the flow path in the molding die (hereinafter simply referred to as “mold”), and becomes a molded product of the cured body. Unfilled sites and voids tend to occur. On the other hand, when the gelation time is longer than 200 seconds, the molded product tends to be insufficiently cured.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of an optical semiconductor device. An optical semiconductor device 200 shown in FIG. 1 includes a pair of lead frames 102 (102a and 102b), an adhesive member 103 provided on one lead frame 102a, and an optical semiconductor element 104 provided on the adhesive member 103. A wire 105 that electrically connects the optical semiconductor element 104 and the other lead frame 102b, and a part of the pair of lead frames 102, an adhesive member 103, an optical semiconductor element 104, and a sealing member 106 that seals the wire 105 And have. The optical semiconductor device 200 is called a surface mount type.

  The lead frame 102 includes one lead frame 102a and the other lead frame 102b. The lead frame 102 is a member made of a conductive material such as metal, and the surface thereof is usually covered with silver plating. Also, one lead frame 102a and the other lead frame 102b are separated from each other. The adhesive member 103 is a member for bonding and fixing one lead frame 102a and the optical semiconductor element 104 to each other and electrically connecting them. The adhesive member 103 is formed from, for example, a silver paste.

  Examples of the optical semiconductor element 104 include a light emitting diode element that emits light when a voltage is applied in the forward direction. The wire 105 is a conductive wire such as a thin metal wire that can electrically connect the optical semiconductor element 104 and the other lead frame 102b.

  The sealing member 106 is formed of a cured body of the urethane resin composition. Since the sealing member 106 protects the optical semiconductor element 104 from the outside air and plays a role of taking out light emitted from the optical semiconductor element 104 to the outside, it has high light transmittance. In the present embodiment, the sealing member 106 collects light emitted from the optical semiconductor element 104 by the lens portion 106b having a convex lens shape.

  The optical semiconductor device 200 of the present embodiment described above can employ liquid transfer molding or compression molding as part of its manufacturing process, thereby shortening the molding time and improving productivity. . Further, by adopting liquid transfer molding or compression molding, an effect of providing a lens shape that improves the light extraction efficiency as shown in FIG. 1 can be obtained.

  The optical semiconductor device 200 only needs to include an optical semiconductor element and a sealing member that seals the optical semiconductor element, and may be a shell type instead of the surface mount type as described above.

  Next, a preferred embodiment of a method for manufacturing an optical semiconductor device will be described taking as an example the case of manufacturing the optical semiconductor device 200 of FIG. The manufacturing method of the optical semiconductor device 200 according to the present embodiment includes a step of forming the sealing member 106 of the optical semiconductor device 200 by curing the urethane resin composition by liquid transfer molding or compression molding.

  The assembly component includes a pair of lead frames 102 (102a and 102b), an adhesive member 103 provided on one of the lead frames 102a, an optical semiconductor element 104 formed on the adhesive member 103, and an optical semiconductor element 104. And a wire 105 that electrically connects the other lead frame 102b. First, this structure is installed at a predetermined position in a cavity formed by a mold provided in the molding apparatus. The molding apparatus is not particularly limited as long as it is used for liquid transfer molding or compression molding, and the cavity formed by the mold has the shape of the target cured body.

  Next, the urethane resin composition is prepared, filled in a pot of a molding apparatus, a plunger is started, and the urethane resin composition is passed from the pot through a flow path such as a runner or a gate. And press-fitted into the cavity of the mold heated to a predetermined temperature. The mold is usually composed of a separable upper mold and a lower mold, and a cavity is formed by connecting them. Then, the urethane resin composition filled in the cavity is cured on the structure by holding the urethane resin composition in the cavity for a certain period of time. As a result, the cured body of the urethane resin composition is molded into a target shape, and seals a plurality of assembly parts and adheres closely to the structure.

  The mold temperature is preferably set to such a temperature that the fluidity of the urethane resin composition is high in the flow path, and the urethane resin composition can be cured in a short time in the cavity. Although this temperature is dependent also on the composition of the said urethane resin composition, it is suitable that it is 120-200 degreeC, for example. Moreover, it is preferable to set the pressure at which the urethane resin composition is press-fitted into the cavity so that the urethane resin composition can be filled in the entire cavity without any gap, specifically, 2 MPa or more. It is preferable. When the spray pressure is 2 MPa or more, unfilled portions in the cavity and voids in the sealing member 106 tend not to be generated.

  In order to make it easy to take out the cured body of the urethane resin composition (sealing member 106) from the mold, a release agent may be applied or sprayed onto the inner wall surface of the mold forming the cavity. Furthermore, in order to suppress generation | occurrence | production of the void in a hardening body, you may use the well-known reduced pressure molding apparatus which can pressure-reduce the inside of a cavity.

  Subsequently, after the structure and the cured body of the urethane resin composition adhered thereto are taken out of the cavity, the lead frame is cut so as to separate the plurality of assembly parts individually. Thus, an optical semiconductor device provided with the cured body of the urethane resin composition as a sealing member for sealing the assembly component is obtained.

  According to the manufacturing method of the optical semiconductor device of this embodiment described above, since the liquid transfer molding method or the compression molding method is adopted, the curing time can be set short, and the productivity of the optical semiconductor device is improved. Moreover, it becomes possible to give arbitrary shapes to a hardening body by using the said shaping | molding method.

  When an optical semiconductor device is produced by a casting method or a potting method using the urethane resin composition of the present embodiment, it varies depending on the type, combination, and amount of each component, but is 1 to 10 at 60 to 150 ° C. It is preferable to heat and cure for about an hour, and in particular, it is preferable to be about 1 to 10 hours at 80 to 150 ° C. Moreover, in order to reduce the internal stress generated by the rapid curing reaction, it is preferable to raise the curing temperature stepwise.

  The cured product of the urethane resin composition according to the present embodiment described above has high light transmittance, excellent optical characteristics such as heat resistance and light-resistant coloring, and mechanical characteristics. Light emitting diode (LED), phototransistor, photodiode, solid It is suitable as a sealing member for use in an optical semiconductor element such as an imaging element. In addition, by using the urethane resin composition of the present embodiment, it is possible to efficiently perform sealing of an optical semiconductor element that is uniform and has few defects such as bubbles by liquid transfer molding, and an optical semiconductor device such as an LED package can be obtained. It becomes possible to manufacture with high productivity.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these at all. The blending ratio is part by mass unless otherwise specified.

Example 1
As a polyol component, 2 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A1) having a hydroxyl value of 670 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 88.80 parts by mass of isophorone diisocyanate (manufactured by Degussa, trade name: VESTANAT IPDI, B1) and 8.93 parts by mass of trimethylolpropane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) are stirred at 80 ° C. in a nitrogen atmosphere. It was made to react for 8 hours, and the isocyanate group residual prepolymer (P1) was produced. 12.5 parts by mass of isophorone diisocyanate (B1) is added to 52.3 parts by mass of this isocyanate group-remaining prepolymer, and [2- {3- (3-tert-butyl-4-] is used as a hindered phenolic antioxidant. Hydroxy-5-methylphenyl) propionyl} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GA-80, F) 0.1 part by mass was mixed to obtain a liquid B containing an isocyanate component having an isocyanate group content of 28.02%. 35.7 parts by mass of the A liquid and 64.3 parts by mass of the B liquid were mixed and stirred at room temperature to obtain a urethane resin composition.

(Example 2)
As a polyol component, 3 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A2) having a hydroxyl value of 550 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 11.0 parts by mass of isophorone diisocyanate (B1) is added to 48.3 parts by mass of the isocyanate group residual prepolymer (P1) of Example 1, and 0.1 parts by mass of a hindered phenolic antioxidant (F) is further mixed. A liquid B containing an isocyanate component having an isocyanate group content of 28.02% was obtained. 40.6 mass parts of said A liquid and 59.4 mass parts of B liquid were mixed and stirred at room temperature, and the urethane resin composition was obtained.

Example 3
As a polyol component, 2 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A1) having a hydroxyl value of 670 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 19.6 parts by mass of isophorone diisocyanate (B1) was added to 43.3 parts by mass of the isocyanate group residual prepolymer (P1) of Example 1, and 0.1 parts by mass of a hindered phenolic antioxidant (F) was further mixed. A liquid B containing an isocyanate component having an isocyanate group content of 29.55% was obtained. 36.9 mass parts of said A liquid and 63.0 mass parts of B liquid were mixed and stirred at room temperature, and the urethane resin composition was obtained.

Example 4
As a polyol component, 3 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A2) having a hydroxyl value of 550 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 18.1 parts by mass of isophorone diisocyanate (B1) is added to 39.9 parts by mass of the residual isocyanate group prepolymer (P1) of Example 1, and 0.1 parts by mass of a hindered phenolic antioxidant (F) is further mixed. A liquid B containing an isocyanate component having an isocyanate group content of 29.55% was obtained. 41.9 mass parts of said A liquid and 58.1 mass parts of B liquid were mixed and stirred at room temperature, and the urethane resin composition was obtained.

(Example 5)
As a polyol component, 2 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A1) having a hydroxyl value of 670 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 19.6 parts by mass of isophorone diisocyanate (B1) was added to 43.3 parts by mass of the residual isocyanate group prepolymer (P1) of Example 1, and further 0.1 part by mass of a hindered phenolic antioxidant (F) and stearin. 0.05 parts by mass of zinc oxide (Nippon Yushi Co., Ltd., trade name: MZ-2, D) was mixed to obtain a liquid B containing an isocyanate component having an isocyanate group content of 28.02%. 36.9 mass parts of said A liquid and 63.05 mass parts of B liquid were mixed and stirred at room temperature, and the urethane resin composition was obtained.

(Comparative Example 1)
As a polyol component, 1 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A3) having a hydroxyl value of 880 mg / g KOH, and a polyol component A liquid was obtained. Meanwhile, 61.7 parts by mass of norbornene diisocyanate (Mitsui Takeda Chemical Co., Ltd.) trade name: Cosmonate NBDI, B2) was selected as the isocyanate component, and an isocyanate component B liquid having an isocyanate content of 40.2% was obtained. . 38.3 parts by mass of the above A liquid and 61.8 parts by mass of B liquid were mixed and stirred at room temperature to obtain a urethane resin composition.

(Comparative Example 2)
As a polyol component, 3 mol of propylene oxide was added to 1 mol of glycerin to prepare a polyol (A4) having a hydroxyl value of 680 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 11.6 parts by mass of isophorone diisocyanate (B1) is added to 51.2 parts by mass of the isocyanate group residual prepolymer (P1) of Example 1, and 0.1 parts by mass of a hindered phenol antioxidant (F) is further mixed. A liquid B containing an isocyanate component having an isocyanate group content of 28.02% was obtained. 37.1 parts by mass of the above A liquid and 62.9 parts by mass of B liquid were mixed and stirred at room temperature to obtain a urethane resin composition.

(Comparative Example 3)
As a polyol component, 2 mol of propylene oxide was added to 1 mol of trimethylolpropane to prepare a polyol (A1) having a hydroxyl value of 670 mg / g KOH, and a polyol component A liquid was obtained. On the other hand, 22.7 parts by mass of isophorone diisocyanate (B1) is added to 39.8 parts by mass of the residual isocyanate group prepolymer (P1) of Example 1, and further 0.1 part by mass of a hindered phenolic antioxidant (F) is mixed. A liquid B containing an isocyanate component having an isocyanate group content of 30.15% was obtained. 37.4 parts by mass of the above A liquid and 62.6 parts by mass of B liquid were mixed and stirred at room temperature to obtain a urethane resin composition.

(Comparative Example 4)
A caprolactone polyol having a hydroxyl value of 540 mg / g KOH (manufactured by Daicel Chemical Industries, trade name: Plaxel 303) was used as the polyol component. On the other hand, 20.7 parts by mass of isophorone diisocyanate (B1) is added to 36.4 parts by mass of the isocyanate group residual prepolymer (P1) of Example 1, and 0.1 parts by mass of a hindered phenolic antioxidant (F) is further mixed. And isocyanate group content 30.15. B liquid containing% isocyanate component was obtained. 42.8 mass parts of said A liquid and 57.2 mass parts of B liquid were mixed and stirred at room temperature, and the urethane resin composition was obtained.

  Table 1 shows the amount of each material used in Examples 1 to 5, and Table 2 shows the amount of each material used in Comparative Examples 1 to 4. Moreover, the urethane resin composition obtained as mentioned above was evaluated according to the following method.

<Compatibility>
The compatibility of liquid A and liquid B when the polyol component A liquid and the isocyanate component B liquid prepared in Examples and Comparative Examples were mixed and stirred at room temperature was evaluated under the following conditions. The compatibility is defined as compatibility: A when the mixed solution is transparent after being stirred and mixed at 2000 rpm for 3 minutes using a self-revolution type stirring and mixing apparatus, and compatibility: B when the mixture is suspended in white. The results are shown in Tables 1 and 2.

<Glass transition temperature>
The Tg of the cured product of the urethane resin composition was measured with a thermomechanical analyzer. The cured product was prepared by casting a urethane resin composition into an aluminum cup and curing it at 80 ° C./30 minutes, 100 ° C./30 minutes, 125 ° C./1 hour, 150 ° C./3 hours. Table 1 shows Tg of the obtained cured product. However, in Comparative Examples 1 to 4, since the compatibility of the resin composition was insufficient and a uniform cured body could not be obtained, Tg could not be measured, and “*” was written.

  In Examples 1-5, the transparent resin composition was obtained and the glass transition temperature of any hardening body was 100 degreeC or more. On the other hand, in Comparative Examples 1-3, the resin composition after stirring and mixing was suspended and inferior in compatibility. In Comparative Example 4, although compatibility was obtained, the glass transition temperature of the cured body was 75 ° C. and less than 100 ° C.

  DESCRIPTION OF SYMBOLS 102,102a, 102b ... Lead frame, 103 ... Adhesive member, 104 ... Optical semiconductor element, 105 ... Wire, 106 ... Sealing member, 106a ... Flat plate part, 106b ... Lens part, 200 ... Optical semiconductor device.

Claims (7)

A two-component urethane resin composition comprising a liquid A containing a polyol component and a liquid B containing a polyisocyanate component,
The polyol component contains a trifunctional or higher functional polyol compound having a hydroxyl value of 550 to 675 mgKOH / g,
The polyisocyanate component contains an alicyclic polyisocyanate and an isocyanate group residual prepolymer of the alicyclic polyisocyanate, and has an isocyanate group content of 26.0 to 30.0% by mass. Resin composition.   The two-component urethane resin composition according to claim 1, wherein the polyol compound is a compound obtained by adding 2 to 3 moles of propylene oxide or ethylene oxide to 1 mole of trimethylolpropane.   The two-component urethane resin composition according to claim 1 or 2, wherein the alicyclic polyisocyanate is isophorone diisocyanate.   The two-component urethane resin composition according to any one of claims 1 to 3, wherein the solution B further contains zinc stearate having a bulk density of 0.12 g / mL or less. A liquid containing a polyol component containing a trifunctional or higher functional polyol compound having a hydroxyl value of 550 to 675 mgKOH / g;
Liquid B containing an alicyclic polyisocyanate and an isocyanate group residual prepolymer of the alicyclic polyisocyanate, and containing a polyisocyanate component having an isocyanate group content of 26.0 to 30.0% by mass;
Hardened | cured material obtained by hardening | curing the urethane resin composition which consists of this by mixing the said A liquid and the said B liquid.   The hardened | cured material of Claim 5 in which the said A liquid and / or the said B liquid further contain an inorganic filler.   An optical semiconductor device provided with the sealing member which consists of a hardening body of Claim 5 or 6.

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