JP2010074124A - Optical semiconductor device, method for manufacturing package substrate for mounting optical semiconductor element, and method for manufacturing optical semiconductor device using package substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor device capable of sufficiently suppressing deterioration of luminance. <P>SOLUTION: The optical semiconductor device 10 is provided with: an optical semiconductor element 8 connected to lead electrodes 1a, 1b; a package molded body for mounting the optical semiconductor element having a recess 6 for storing the optical semiconductor element 8; and a seal 20 consisting of resin having translucency and filled in the recess 6 to seal the optical semiconductor element. The package molded body for mounting the optical semiconductor element has: a wiring board 1 having the lead electrodes 1a, 1b on the surface; and a light reflection layer 5 consisting of a hardened material of thermosetting resin composition and formed on the board. The recess 6 is formed by a hole provided from the surface of the light reflection layer 5 to the surface on the board side, and the bottom 6a of the recess 6 is formed by the hardened material 5a of the resin composition for optical reflection layer 5 and the lead electrodes 1a, 1b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical semiconductor device that includes an optical semiconductor element and a package molded body that accommodates the optical semiconductor element and has a recess having a reflector function for extracting light to the outside. The present invention also relates to a method of manufacturing a package substrate for mounting an optical semiconductor element and a method of manufacturing an optical semiconductor device using the package substrate.

  Light Emitting Diodes (LEDs), which are optical semiconductor elements, are attracting attention as inexpensive and long-life elements, and are widely used in various indicators, light sources, flat display devices, liquid crystal display backlights, and the like. . As an example of such an optical semiconductor device, there is one in which an optical semiconductor element is mounted on a package substrate having a fiber-containing substrate and a resin molded body formed on the substrate (see Patent Document 1). 5A and 5B are a cross-sectional view and a plan view showing an example of a conventional optical semiconductor device.

  The optical semiconductor device 50 illustrated in FIG. 5 is generally classified as “surface mount type”. The optical semiconductor device 50 is filled to cover the wiring board 51, the light reflection layer 55 formed on the wiring board 51, the optical semiconductor element 60 mounted on the wiring board 51, and the optical semiconductor element 60. And a sealing body 20 made of a transparent resin. The wiring board 51 has a pair of lead electrodes 51a and 51b and a fiber-containing substrate 51c provided on the surface thereof. The light reflecting layer 55 has a structure in which the lead electrodes 51a and 51b on the wiring board 51 are molded with a thermosetting resin. A solder resist 52 is provided between the wiring board 51 and the light reflection layer 55. The solder resist 52 is for preventing the resin from flowing into the region 9 where the optical semiconductor element 60 is mounted when the light reflecting layer 55 is provided on the wiring board 51. That is, when the light reflecting layer 55 is provided, the mount region 9 is covered with a mold, and the mold is brought into contact with the peripheral edge 52a of the solder resist 52, thereby preventing the resin from flowing into the mount region 9. To do.

  After the formation of the light reflection layer 55, the optical semiconductor element 60 is placed on the mount region 9 via the die bond material 15. An electrode (not shown) of the optical semiconductor element 60 and the lead electrodes 51 a and 51 b are connected by the bonding wire 16. Thereafter, the sealing body 20 is formed by filling the recess 56 formed by the mount region 9 and the light reflection layer 55 with a transparent resin. The optical semiconductor element 60 emits light when power is supplied through the two lead electrodes 51a and 51b, and the light is extracted from the light extraction surface 50F through the sealing body 20.

  In the field of light emitting devices as described above, the package size tends to be reduced with the recent progress of thinner and smaller electronic devices. As a process for producing a small package with high productivity, a transfer molding method in which a thermosetting resin is molded is proposed (see Patent Document 2).

JP 2007-142253 A JP 2007-235085 A

  By the way, when the present inventor conducted a long-term lighting test on the conventional optical semiconductor device as illustrated in FIG. As a result of studying this phenomenon, the present inventor has found that one reason is that the fiber-containing substrate is colored and deteriorated by heat and light. That is, with reference to FIG. 5, the portion of the mount region 9 where the base material 51 c is exposed (exposed portion 9 a) is deteriorated and colored by the heat and light of the optical semiconductor element 60, and thereby the light reflectance is increased. It is presumed that the luminance decreases due to the decrease.

  According to the inventor's investigation, the coloring of the exposed portion 9a is presumed to be the main cause that the resin having a skeleton containing a benzene ring contained in the fiber-containing base material 51c is oxidized by heat and light and turns brown. . Thus, in manufacturing an optical semiconductor device, an optical semiconductor device in which a conventional resin composition is used as a substrate or a substrate sufficiently suppresses a decrease in luminance caused by coloring of a portion exposed to heat or light. It was difficult to do.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an optical semiconductor device capable of sufficiently suppressing a decrease in luminance and a method for efficiently manufacturing the same. Another object of the present invention is to provide a method of manufacturing a package substrate for mounting an optical semiconductor element that is useful for efficiently manufacturing the semiconductor device.

  An optical semiconductor device according to the present invention comprises an optical semiconductor element connected to a lead electrode, an optical semiconductor element mounting package having a concave portion for accommodating the optical semiconductor element, and a light-transmitting resin. And a sealing body that is filled to seal the optical semiconductor element. The packaged body for mounting an optical semiconductor element includes a wiring board having lead electrodes on the surface, and a light reflecting layer made of a cured product of a thermosetting resin composition and formed on the wiring board. The concave portion is formed by a hole provided from the surface of the light reflecting layer to the surface on the wiring board side, and the bottom surface of the concave portion is a cured product of the thermosetting resin composition and a lead electrode on the surface of the wiring board. Is formed by.

  In the optical semiconductor device, the bottom surface of the recess is formed by the cured product of the thermosetting resin composition and the lead electrode, and the base material of the wiring board is not exposed on the bottom surface. For this reason, the fall of the reflectance by discoloration of resin contained in a base material can fully be suppressed. For this reason, the above-mentioned optical semiconductor device is sufficiently low in luminance even when used for a long time, and can achieve high reliability.

  The present invention is a method for manufacturing a package substrate for mounting an optical semiconductor element, wherein a light reflecting layer made of a cured product of a thermosetting resin composition and having a plurality of holes forming recesses for accommodating the optical semiconductor element Provided is a method of forming a light reflecting layer by transfer molding, comprising a step of forming on a wiring board having a lead electrode connected to a semiconductor element. By adopting transfer molding, the light reflecting layer can be efficiently formed on the wiring board. Specifically, lead time can be shortened, materials used can be reduced, and costs can be reduced.

  In the present invention, the thermosetting resin composition for forming the light reflecting layer includes (A) an epoxy resin, (B) a curing agent, (C) a curing accelerator, (D) an inorganic filler, (E) It contains a white pigment and (F) a coupling agent, and the cured product of the thermosetting resin composition preferably has a light reflectance of 80% or more at a wavelength of 450 nm to 800 nm. By adopting such a configuration, a light reflection layer having a sufficiently high reflector function can be formed. The thermosetting resin composition is preferably one that can be pressure-molded at room temperature (25 ° C.) before thermosetting from the viewpoint of easy formation of the light reflecting layer.

  (D) The inorganic filler is composed of silica, alumina, magnesium oxide, antimony oxide, aluminum hydroxide, barium sulfate, magnesium carbonate, and barium carbonate in terms of thermal conductivity, light reflection characteristics, moldability, and flame retardancy. It is preferably at least one selected from the group. (E) The white pigment is preferably titanium oxide from the viewpoint of light reflection characteristics. (E) The average particle diameter of the white pigment is preferably in the range of 0.1 to 50 μm from the viewpoint of suppressing particle aggregation and achieving excellent light reflection characteristics.

  The total amount of (D) inorganic filler and (E) white pigment is 100 parts by volume of the thermosetting resin composition from the viewpoint of achieving both the excellent light reflection characteristics and moldability of the light reflection layer at a high level. On the other hand, it is preferably within the range of 60 to 85 parts by volume.

  In the present invention, a printed wiring board, a flexible wiring board, or a metal base wiring board can be used as the wiring board.

  The present invention is a method of manufacturing an optical semiconductor device, the first step of mounting the optical semiconductor element on each bottom surface of the recess of the optical semiconductor element mounting package substrate manufactured by the above method, and the optical semiconductor element And a second step of filling the concave portion with a light-transmitting sealing resin so as to cover the concave portion. According to this method, an optical semiconductor device that can sufficiently suppress a decrease in luminance can be efficiently manufactured.

  The method for manufacturing an optical semiconductor device according to the present invention further includes a third step of dividing the optical semiconductor element mounting package substrate on which the plurality of optical semiconductor elements are mounted to obtain a plurality of optical semiconductor devices after the second step. It is preferable. The division of the package substrate for mounting an optical semiconductor element in the third step can be performed by dicing.

  According to the present invention, it is possible to suppress a decrease in reflectance on the surface of the wiring board that forms the bottom surface of the concave portion of the package for mounting an optical semiconductor element, and thus it is possible to sufficiently suppress a decrease in luminance of the optical semiconductor device. As a result, according to the present invention, an optical semiconductor device having sufficiently high reliability is provided.

(A) And (b) is sectional drawing and top view which show suitable embodiment of the optical semiconductor device which concerns on this invention. It is process drawing which shows suitable embodiment of the manufacturing method of the package substrate for optical semiconductor element mounting which concerns on this invention. It is a top view which shows one Embodiment of the optical semiconductor device manufactured by the method based on this invention. It is sectional drawing which shows other embodiment of the optical semiconductor device which concerns on this invention. (A) And (b) is sectional drawing and a top view which show the structure of the conventional optical semiconductor device.

<Optical semiconductor device>
The optical semiconductor device 10 shown in FIG. 1 is generally classified as a “surface mount type”. The optical semiconductor device 10 includes a wiring board 1, a light reflecting layer 5 formed on the wiring board 1, an optical semiconductor element 8 connected to the lead electrodes 1a and 1b, and a resin material having translucency (hereinafter referred to as a light-transmitting resin material). And a sealing body 20 made of “transparent sealing resin”. In the present embodiment, a package molded body for mounting an optical semiconductor element is formed by the wiring board 1 and the light reflecting layer 5. On the surface of the wiring board 1, lead electrodes 1a and 1b, a circuit 1c, and the like are provided. The substrate 1d of the wiring board 1 is formed of a resin material.

  The light reflecting layer 5 is made of a cured product of a thermosetting resin composition, and is formed on the lead electrodes 1 a and 1 b of the wiring board 1. The light reflecting layer 5 has a hole provided from its upper surface to the surface on the wiring board 1 side. A recess 6 is formed by a hole of the light reflecting layer 5, and three optical semiconductor elements 8 are accommodated therein. In the recess 6, the lead electrodes 1 a, 1 b on the wiring board 1 and the cured product of the resin composition for the light reflecting layer 5 filled therebetween are exposed, forming the bottom surface 6 a of the recess 6. The cured product between the lead electrodes 1 a and 1 b is provided simultaneously with the light reflecting layer 5. In order to fill the thermosetting resin composition between the lead electrodes 1a and 1b when forming the light reflecting layer 5, for example, when forming the light reflecting layer 5, use a solder resist (see FIG. 5). Instead, transfer molding may be performed. In the case where a solder resist is not used, resin burrs tend to be generated in the mount region 9, but the occurrence of resin burrs can be sufficiently reduced by adjusting the composition and kneading conditions of the resin composition.

  The optical semiconductor element 8 is mounted on the recess 6 formed in the light reflecting layer 5 through the die bond material 15. An electrode (not shown) of the optical semiconductor element 8 and the lead electrodes 1 a and 1 b are connected by a bonding wire 16. Thereafter, a resin material having translucency is filled around the optical semiconductor element 8, that is, in the recess 6 to form the sealing body 20. The optical semiconductor element 8 emits light when electric power is supplied through the two lead electrodes 1a and 1b, and the light is extracted from the light extraction surface 10F through the sealing body 20.

  According to the optical semiconductor device 10 having the above-described configuration, even when used for a long period of time, an excellent effect is achieved in that a decrease in luminance is sufficiently small and high reliability can be achieved. That is, in the optical semiconductor device 10, the bottom surface 6a of the recess 6 is formed by the cured product 5a of the resin composition for the light reflecting layer 5 and the lead electrodes 1a and 1b. Since the base material 1d of the wiring board 1 is not exposed on the bottom surface 6a, it is possible to sufficiently suppress a decrease in reflectance due to discoloration of the resin contained in the base material 1d.

  The optical semiconductor device 10 has a configuration in which the wiring board 1 is located immediately below the light reflecting layer 5 having the recess 6. For this reason, there is an advantage that the light emission of the three optical semiconductor elements 8 accommodated in the recesses 6 can be controlled relatively easily by appropriately designing the circuit pattern of the wiring board 1. From this point of view, it is preferable to mount a plurality of optical semiconductor elements 8 in the recess 6.

(Wiring board)
As the wiring board 1, the wiring used as a circuit was formed using the well-known method with respect to the thermosetting resin board | substrate with a fiber with a copper foil, the film board with a copper foil, or the metal base board with a copper foil. Things can be used. The thickness of the wiring conductor is preferably in the range of 18 to 150 μm, and more preferably in the range of 35 to 70 μm. If the thickness of the wiring conductor is less than 18 μm, the heat capacity tends to be small and the heat dissipation tends to be gradually reduced. When it is thicker than 150 μm, it is preferable from the viewpoint of heat dissipation, but the wiring formation tends to become difficult gradually. After the wiring is formed, Ni / silver plating is performed by electroplating. A resin containing a benzene ring skeleton may be used as the resin constituting the substrate 1d.

(Light reflecting layer)
The light reflection layer 5 is made of a cured product of a thermosetting resin composition. The thermosetting resin composition is preferably one that can be pressure-molded at room temperature (25 ° C.) before thermosetting from the viewpoint of easy formation of the light reflecting layer. As the thermosetting resin contained in the thermosetting resin composition, various resins such as an epoxy resin, a silicone resin, a urethane resin, and a cyanate resin can be used. In particular, an epoxy resin is preferable because of its excellent adhesion to various materials.

(A) Epoxy resin As an epoxy resin, what is generally used with the epoxy resin molding material for electronic component sealing which does not contain a benzene ring can be used. Specific examples include epoxidized phenol and aldehyde novolak resins such as hydrogenated phenol novolac epoxy resins, orthocresol novolac epoxy resins, hydrogenated bisphenol A, bisphenol F, and bisphenol S. , Glycidylamine type epoxy resin obtained by reaction of polychlorinated diglycidyl ether such as alkyl-substituted bisphenol, diaminodiphenylmethane, isocyanuric acid and epichlorohydrin, linear aliphatic obtained by oxidizing olefinic bonds with peracid such as peracetic acid An epoxy resin, an alicyclic epoxy resin, etc. can be mentioned. These resins may be used alone or in combination of two or more. Among these resins, it is preferable to use those which are relatively uncolored, such as hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, diglycidyl isocyanurate, triglycidyl. Isocyanurate is preferred.

  When an epoxy resin is used as the thermosetting resin, it is preferable to mix a curing agent and a curing accelerator in the thermosetting resin composition.

(B) Curing agent As the curing agent, any curing agent that can react with an epoxy resin can be used without particular limitation. For example, an acid anhydride curing agent, an isocyanuric acid derivative, a phenolic curing agent, and the like can be given. Examples of the acid anhydride curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, glutaric anhydride. Acid, dimethylglutaric anhydride, diethylglutaric anhydride, succinic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Examples of isocyanuric acid derivatives include 1,3,5-tris (1-carboxymethyl). ) Isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, 1,3,5-tris (3-carboxypropyl) isocyanurate, 1,3-bis (2-carboxyethyl) isocyanurate, etc. Is mentioned.

  Among the above curing agents, phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, glutaric anhydride, dimethylglutaric anhydride, diethylglutaric anhydride It is preferable to use an acid, 1,3,5-tris (3-carboxypropyl) isocyanurate. The curing agent preferably has a molecular weight of about 100 to 400, and is preferably colorless or light yellow.

  It is preferable that content of the hardening | curing agent of a thermosetting resin composition is 50-200 mass parts with respect to 100 mass parts of epoxy resins, More preferably, it is 100-150 mass parts. When the content of the curing agent is less than 50 parts by mass, the curing reaction of the epoxy resin may not sufficiently proceed, and when it exceeds 200 parts by mass, discoloration may be seen in the obtained molded body. .

(C) Curing accelerator The curing accelerator is not particularly limited. For example, 1,8-diaza-bicyclo (5,4,0) undecene-7, triethylenediamine, tri-2,4,6. -Tertiary amines such as dimethylaminomethylphenol, imidazoles such as 2-ethyl-4methylimidazole and 2-methylimidazole, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetra-n-butylphosphonium-o, o -Phosphorus compounds such as diethyl phosphorodithioate, tetra-n-butylphosphonium-tetrafluoroborate, tetra-n-butylphosphonium-tetraphenylborate, quaternary ammonium salts, organometallic salts, and derivatives thereof . These may be used individually by 1 type and may use 2 or more types together. Among these curing accelerators, it is preferable to use tertiary amines, imidazoles, and phosphorus compounds.

  It is preferable that content of the hardening accelerator of a thermosetting resin composition is 0.01-8.0 mass parts with respect to 100 mass parts of epoxy resins, More preferably, it is 0.1-3.0 masses. Part. When the content of the curing accelerator is less than 0.01 parts by mass, a sufficient curing acceleration effect may not be obtained. When the content exceeds 8.0 parts by mass, discoloration is observed in the obtained molded product. May be.

(D) Inorganic filler The inorganic filler is selected from the group consisting of silica, alumina, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate and barium carbonate. At least one kind can be used. At least one selected from the group consisting of silica, alumina, magnesium oxide, antimony oxide, aluminum hydroxide, barium sulfate, magnesium carbonate and barium carbonate from the viewpoint of thermal conductivity, light reflection characteristics, moldability and flame retardancy It is preferable to use it. The particle size of the inorganic filler is not particularly limited, but it is preferable to use one having a particle size in the range of 1 to 100 μm so that packing with the white pigment is efficient.

  From the viewpoint of the flame retardant effect, it is preferable to use aluminum hydroxide or magnesium hydroxide as the inorganic filler. Since aluminum hydroxide and magnesium hydroxide are white, they are preferable in that they do not affect the reflectance. Moreover, it is preferable to use aluminum hydroxide and magnesium hydroxide with few ionic impurities from a viewpoint of moisture resistance reliability. The content of the Na compound (ionic compound) contained in the inorganic filler is preferably 0.2% by mass or less. The average particle diameter of aluminum hydroxide or magnesium hydroxide used as the inorganic filler is not particularly limited, but is preferably 0.1 to 50 μm from the viewpoint of flame retardancy and fluidity. As for the compounding quantity of aluminum hydroxide and magnesium hydroxide, 10-30 mass% is preferable on the basis of the total mass of a thermosetting resin composition. When the blending amount is less than 10% by mass, it becomes difficult to obtain the flame retarding effect gradually, and when it exceeds 30% by mass, the fluidity and curability may be adversely affected.

  It is preferable that the compounding quantity of an inorganic filler is the range of 10-85 volume% on the basis of the whole volume of a thermosetting resin composition. If the blending amount is less than 10% by volume, the light reflection characteristics tend to be insufficient. On the other hand, if it exceeds 85% by volume, the moldability tends to deteriorate and the light reflection layer 5 tends to be difficult to mold.

(E) White pigment As the white pigment, alumina, magnesium oxide, antimony oxide, titanium oxide, or zirconium oxide can be used. Among these, titanium oxide is preferable from the viewpoint of light reflectivity. Inorganic hollow particles may be used as the white pigment. Specific examples of the inorganic hollow particles include sodium silicate glass, aluminum silicate glass, borosilicate soda glass, and shirasu. The white pigment preferably has an average particle size in the range of 0.1 to 50 μm. When the average particle size is less than 0.1 μm, the particles tend to aggregate and the dispersibility tends to deteriorate. On the other hand, when the average particle size exceeds 50 μm, the light reflection characteristics tend to be insufficient.

  It is preferable to adjust the blending amount of the white pigment in consideration of the blending amount of the inorganic filler. The total amount of the white pigment and the inorganic filler is preferably in the range of 60 to 85% by volume based on the total volume of the thermosetting resin composition.

  The thermosetting resin composition may further contain a coupling agent. Examples of coupling agents include silane coupling agents and titanate coupling agents. From the viewpoint of coloring, epoxy silane is generally excellent, and specific examples include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- Examples include glycidoxypropylmethyldimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. The blending amount of the coupling agent is preferably not more than mass% based on the total mass of the thermosetting resin composition. In the thermosetting resin composition, an antioxidant, a release agent, an ion scavenger and the like may be blended as other additives.

(Sealed body)
The sealing body 20 is made of a transparent sealing resin, and fills the recess 6 to protect the optical semiconductor element 8. The transparent sealing resin preferably has an elastic modulus of 1 MPa or less at room temperature (25 ° C.). In particular, it is preferable to employ a silicone resin or an acrylic resin from the viewpoint of transparency. The transparent sealing resin may further contain an inorganic filler that diffuses light and a phosphor that emits white light using blue light as an excitation source.

(Manufacturing method of package substrate)
The optical semiconductor device 10 shown in FIG. 1 can be mass-produced efficiently by using a package substrate for mounting an optical semiconductor element. A method for manufacturing the package substrate 30 will be described with reference to FIG. First, after forming a circuit on a copper-clad laminate or the like, a lead electrode is further formed on the surface by Ni / Ag plating to obtain a wiring board 31. Note that a metal core substrate, a flexible substrate, or the like may be used as the wiring board 31.

  As shown in FIG. 2A, a wiring board 31 is disposed between a pair of molds 40a and 40b. Next, as shown in FIG. 2B, a thermosetting resin composition is injected from a resin injection port (not shown) of the molds 40 a and 40 b to form a light reflection layer 35 on the wiring board 31. . The light reflecting layer 35 is preferably formed by a transfer molding method. After injecting the resin composition for the light reflecting layer 35, for example, the resin composition is cured by maintaining the mold temperature at 180 ° C. for 90 seconds. It is preferable to reduce the pressure in the mold during transfer molding because the resin filling property between the lead electrodes 1a and 1b is improved. After taking out the package substrate 30 from the molds 40a and 40b, the thermosetting resin composition may be after-cured by heating at a temperature of 120 ° C. to 180 ° C. for 1 to 3 hours. The package substrate 30 is manufactured through these steps. As shown in FIG. 2C, the package substrate 30 includes a wiring board 31 and a light reflection layer 35 provided thereon, and the light reflection layer 35 has a plurality of recesses 6.

(Manufacturing method of optical semiconductor device)
The optical semiconductor element 8 is mounted in each recess 6 of the package substrate 30 (first step). Thereafter, each recess 6 is filled with a translucent sealing resin so as to cover the optical semiconductor element 8 (second step). As a result, as shown in FIG. 3, a product in which a plurality of optical semiconductor devices 10 are integrally formed is obtained. Thereafter, the divided optical semiconductor device 10 is obtained by dividing the product (third step). Dividing can be performed by dicing.

  However, when the optical semiconductor device 10 is used in a state where the plurality of optical semiconductor devices 10 are integrally provided, the third step may not be performed. Further, the number of the optical semiconductor devices 10 of the product shown in FIG. 3 is not limited to four. The optical semiconductor device 10 has a configuration in which the wiring board 31 is located immediately below the light reflecting layer 5. For this reason, there is an advantage that the light emission of each optical semiconductor device 10 can be controlled relatively easily by appropriately designing the circuit pattern of the wiring board 31.

  In the second step, the optical semiconductor device 10 may be manufactured using a transparent sealing resin containing a phosphor. In the embodiment shown in FIG. 4A, after the lead electrodes 1a and 1b and the optical semiconductor element 8 are connected by the bonding wire 16, the sealing body 21 is formed by the transparent sealing resin containing the phosphor 21a. It is. In the embodiment shown in FIG. 4B, after the lead electrodes 1a and 1b and the optical semiconductor element 8 are connected by the solder bumps 17, the sealing body 21 is formed by the transparent sealing resin containing the phosphor 21a. It is.

Example 1
<Production of printed wiring board>
A glass cloth-epoxy resin impregnated double-sided copper-clad laminate (trade name: MCL-E-679, substrate thickness 0.6 mm, copper foil thickness 35 μm) manufactured by Hitachi Chemical Co., Ltd. was prepared. The laminated plate was subjected to drilling and electroless plating (thickness 20 μm), and a circuit was formed by the subtract method. Furthermore, a lead electrode was formed on the copper circuit by Ni / Ag plating to produce a printed wiring board.

<Preparation of thermosetting resin composition for light reflecting layer>
A thermosetting resin composition for a light reflection layer was prepared by roll kneading the following components under conditions of a kneading temperature of 20 to 30 ° C. and a kneading time of 10 minutes.

(A) Epoxy resin: triglycidyl isocyanurate, 100 parts by mass (epoxy equivalent 100),
(B) Curing agent: hexahydrophthalic anhydride, 140 parts by mass,
(C) Curing accelerator: tetra-n-butylphosphonium-o, o-diethyl phosphorodithioate, 2.4 parts by mass,
(D) Inorganic filler: fused silica A (average particle size 25 μm), 600 parts by mass, and fused silica B (average particle size 0.25 μm), 890 parts by mass,
(E) White pigment: Titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd., FTR-700, average particle size 0.3 μm), 185 parts by mass,
(F) Coupling agent: Epoxy silane, 19 parts by mass,
(G) Antioxidant: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1 part by mass <Preparation of package substrate for mounting optical semiconductor element>
The printed wiring board produced as described above was positioned and arranged in a mold having the same shape as the molds 40a and 40b shown in FIG. Next, after injecting the thermosetting resin composition into the mold, the mold is depressurized using a transfer molding machine (MF-FS01, manufactured by Mtex Matsumura Co., Ltd.), and then heated and pressed. Thus, an optical semiconductor element mounting package substrate having a plurality of recesses was obtained. The molding conditions were a mold temperature of 180 ° C., a holding time of 90 seconds, and a pressure of 6.9 MPa.

<Manufacture of optical semiconductor devices>
An LED element was disposed on a circuit at the bottom of each recess of the package substrate for mounting an optical semiconductor element via a die bond material (manufactured by Hitachi Chemical Co., Ltd., EN4620K). The LED element was fixed on the terminal by heating at 150 ° C. for 1 hour. Subsequently, the LED element and the terminal of the wiring board were electrically connected with a gold wire. Thereafter, a transparent sealing resin having the following composition was poured into each concave portion by potting and heat-cured at 150 ° C. for 2 hours to seal the LED element.

(Composition of transparent sealing resin)
-Hydrogenated bisphenol A type epoxy resin: Denacol EX252 (manufactured by Nagase ChemteX Corporation), 90 parts by mass,
-Alicyclic epoxy resin: CEL-2021P (manufactured by Daicel Chemical Industries, Ltd.), 10 parts by mass,
4-methylhexahydrophthalic anhydride HN-5500E (manufactured by Hitachi Chemical Co., Ltd.), 90 parts by mass,
2,6-ditertiary butyl-4-methylphenol BHT, 0.4 parts by mass,
-2-ethyl-4-methylimidazole, 0.9 mass part After hardening the said transparent sealing resin, a matrix-shaped optical semiconductor device is separated into pieces using a dicing apparatus (DAD381 by DISCO Corporation). A plurality of single optical semiconductor devices (SMD type LEDs) having one LED element were manufactured.

(Example 2)
An optical semiconductor device was manufactured in the same manner as in Example 1 except that a metal core substrate was used instead of the printed wiring board.

(Example 3)
An optical semiconductor device was manufactured in the same manner as in Example 1 except that a flexible substrate was used instead of the printed wiring board.

(Comparative Example 1)
Prior to forming the light reflecting layer, an optical semiconductor device was manufactured in the same manner as in Example 1 except that the surface of the printed wiring board other than the region serving as the bottom surface of the recess (mounting region) was covered with a solder resist.

(Comparative Example 2)
An optical semiconductor device was manufactured in the same manner as in Example 1 except that the light reflecting layer was formed under atmospheric pressure instead of the transfer molding method.

(Evaluation)
The optical semiconductor devices according to Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated for the following items. The results are shown in Table 1.

(1) Fillability of resin between lead electrodes The concave portion of the optical semiconductor device was visually observed, and the fillability of resin between the lead electrodes was evaluated based on the following criteria.

  A: The resin composition for the light reflection layer is filled between the lead electrodes.

  B: The resin composition for the light reflecting layer is not sufficiently filled between the lead electrodes.

(2) Existence of base material exposure The concave part of the optical semiconductor device was visually observed to evaluate whether the base material of the wiring board was exposed on the bottom surface of the concave part.

(3) Presence / absence of resin coloring Under an atmosphere of 200 ° C., light having a wavelength of 240 to 380 nm was irradiated with an intensity of 0.22 W / cm ² toward the concave portion of the optical semiconductor device for 2 hours. Thereafter, the bottom surface of the concave portion was visually observed to evaluate whether or not coloring of the resin constituting the substrate of the wiring board was observed.

  According to the present invention, the bottom surface of the recess is formed only of the cured product of the resin composition that forms the lead electrode and the light reflecting layer, and the substrate of the wiring board that easily deteriorates against heat and light is not exposed. . For this reason, a reduction in luminance is suppressed, and an optical semiconductor device having high reliability is provided.

  DESCRIPTION OF SYMBOLS 1,31,51 ... Wiring board, 1a, 1b, 51a, 51b ... Lead electrode, 1d, 51c ... Base material, 5, 35, 55 ... Light reflection layer, 5a ... Hardened | cured material of the resin composition for light reflection layers, 6, 56... Recess, 6a... Bottom surface of recess, 8, 60... Optical semiconductor element, 9... Mount region, 9a. ... die bond material, 16 ... bonding wire, 17 ... solder bump, 20, 21 ... sealing body (transparent sealing resin), 21a ... phosphor, 30 ... package substrate for mounting optical semiconductor elements, 40a, 40b ... mold, 52 ... Solder resist, 52a ... Peripheral edge of solder resist.

Claims (11)

An optical semiconductor element connected to the lead electrode;
A package molded body for mounting an optical semiconductor element having a recess for accommodating the optical semiconductor element;
A sealing body made of a resin having translucency, filled in the recess and sealing the optical semiconductor element;
With
The optical semiconductor element mounting package molded body has a wiring board having the lead electrode on the surface thereof, and a light reflecting layer formed on the wiring board made of a cured product of a thermosetting resin composition,
The concave portion is formed by a hole provided from the surface of the light reflecting layer to the surface on the wiring board side, and the bottom surface of the concave portion is formed by the cured product of the thermosetting resin composition and the lead electrode. The formed optical semiconductor device. A method of manufacturing a package substrate for mounting an optical semiconductor element,
Forming a light reflecting layer made of a cured product of a thermosetting resin composition on a wiring board having a lead electrode connected to the optical semiconductor element and having a plurality of holes forming recesses for accommodating the optical semiconductor element. Prepared,
A method of manufacturing a package substrate for mounting an optical semiconductor element, wherein the light reflecting layer is formed by transfer molding. The thermosetting resin composition comprises (A) an epoxy resin, (B) a curing agent, (C) a curing accelerator, (D) an inorganic filler, (E) a white pigment, and (F) a cup. Containing a ring agent,
The method for producing a package substrate for mounting an optical semiconductor element according to claim 2, wherein the cured product of the thermosetting resin composition has a light reflectance of 80% or more at a wavelength of 450 nm to 800 nm.   (D) The optical semiconductor element according to claim 3, wherein the inorganic filler is at least one selected from the group consisting of silica, alumina, magnesium oxide, antimony oxide, aluminum hydroxide, barium sulfate, magnesium carbonate, and barium carbonate. A method for manufacturing a mounting package substrate.   (E) The manufacturing method of the package substrate for optical semiconductor element mounting of Claim 3 or 4 whose white pigment is a titanium oxide.   (E) The manufacturing method of the package substrate for optical semiconductor element mounting as described in any one of Claims 3-5 whose average particle diameter of a white pigment exists in the range of 0.1-50 micrometers.   The total amount of (D) inorganic filler and (E) white pigment is in the range of 60 to 85 parts by volume with respect to 100 parts by volume of the thermosetting resin composition. The manufacturing method of the package board | substrate for optical semiconductor element mounting of description.   The method of manufacturing a package substrate for mounting an optical semiconductor element according to any one of claims 3 to 7, wherein the wiring board having the lead electrode is a printed wiring board, a flexible wiring board, or a metal base wiring board. An optical semiconductor device manufacturing method comprising:
A first step of mounting an optical semiconductor element on each bottom surface of the recess of the package substrate for mounting an optical semiconductor element manufactured by the method according to claim 2;
A second step of filling the recess with a translucent sealing resin so as to cover the optical semiconductor element;
An optical semiconductor device manufacturing method comprising:   The optical semiconductor device according to claim 9, further comprising a third step of dividing the optical semiconductor element mounting package substrate on which the plurality of optical semiconductor elements are mounted to obtain a plurality of optical semiconductor devices after the second step. Manufacturing method.   The method of manufacturing an optical semiconductor device according to claim 10, wherein the optical semiconductor element mounting package substrate is divided by dicing.

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