JP5397195B2 - Manufacturing method of substrate for mounting optical semiconductor element and manufacturing method of optical semiconductor device - Google Patents

Description

  The present invention relates to an optical semiconductor element mounting substrate and a manufacturing method thereof, and an optical semiconductor device and a manufacturing method thereof.

  Electronic devices are becoming smaller, lighter, higher performance, and multifunctional, and electronic components used in electronic devices are desired to be mounted with high density. Many of such electronic components are surface mount devices (SMD) arranged on a printed circuit board, and are connected to a wiring pattern on the printed circuit board by reflow soldering (for example, Patent Documents). 1).

  As an example of an electronic component, an LED (Light Emitting Diode) is an optical semiconductor device that combines, for example, an optical semiconductor element and a phosphor, and has attracted attention as a light-emitting device that has low power consumption and long life. In addition, solid-state imaging devices such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) electrically convert an image of an optical signal formed through a lens. It is applied to television cameras and digital cameras as devices that convert signals.

  In an optical semiconductor device, a substrate on which a molded body having a predetermined shape is pre-molded by transfer molding is used as a substrate on which an optical semiconductor element is mounted. Such a molded body is molded such that the mounting surface on which the optical semiconductor element is mounted is exposed. In recent years, as a method for manufacturing an optical semiconductor device such as an LED, a package in which lead terminals for external connection are taken into the package has attracted particular attention from the viewpoint of miniaturization and high integration.

  As a substrate for mounting an optical semiconductor element, a form called QFN (Quad Flat Nonleaded package) has been studied. As a QFN manufacturing method, MAP (Mold array package) molding, in which a plurality of QFNs are collectively molded and then separated into individual pieces, has attracted particular attention. In MAP molding, a plurality of optical semiconductor elements are arranged on an exposed mounting surface (optical semiconductor element mounting region) in a recess in a patterned lead frame, the optical semiconductor elements are collectively sealed with a transparent resin, and then cut. A plurality of QFNs are obtained by dividing into individual QFN type packages. By MAP molding, productivity per lead frame can be dramatically improved.

  In addition, it is known that a molded body is transfer-molded on a lead frame having a plurality of optical semiconductor element mounting regions and is single-sided molded (see, for example, Patent Document 2). As the material of the molded body, a thermosetting resin composition having excellent adhesive strength with a wiring member such as a lead frame is used.

JP 2003-218398 A JP-A-11-126785

  However, in such a conventional method for manufacturing a substrate for mounting an optical semiconductor element (pre-molded package), when forming a molded body by transfer molding using a mold, the optical semiconductor element mounting region faces the area. Contamination such as flashing of the thermosetting resin composition occurs in the gap with the surface of the mold, resulting in poor connection strength between the optical semiconductor element and a wiring member such as a lead frame and poor connection such as poor conduction. In order to suppress such connection failure, it is possible to perform a deburring process such as wet blasting or plasma processing, but the number of processes increases or the molded product is damaged during the process, resulting in a deterioration in yield. The productivity of the optical semiconductor device is reduced.

  Also, in the method of single-sided molding on the lead frame by transfer molding, when a matrix-like large-sized molded product (for example, 20 mm square or more) is integrally molded, the wire between the resin molded body and the wiring member when heated Stress is generated due to the difference in expansion coefficient. As a result, the optical semiconductor element mounting substrate is warped, and it is difficult to proceed with the subsequent steps, so that the productivity of the optical semiconductor device is lowered.

  The present invention has been made in order to solve the above-described problems, and an optical semiconductor element mounting substrate capable of suppressing the occurrence of poor connection of an optical semiconductor element and the warpage of the substrate while suppressing a decrease in productivity. An object of the present invention is to provide an optical semiconductor device and a manufacturing method thereof.

  The present invention relates to an optical semiconductor element mounting substrate using a mold having a concave portion filled with a thermosetting resin composition and a convex portion serving as a cavity in which an optical semiconductor element is disposed in a molded body. A wiring member placement step in which the other surface of the wiring member having an element placement region on one side where the optical semiconductor element is placed is opposed to each other via an adhesive film; and the convex portion is in contact with the element placement region In addition, a mold placement step in which a pair of molds face each other via a wiring member and an adhesive film, and a thermosetting resin composition is filled in the recess, and a molded body is formed on one surface of the wiring member by transfer molding A formed body forming step.

  In the method for manufacturing a substrate for mounting an optical semiconductor element according to the present invention, the wiring member and the other side of the wiring member are opposed to each other through an adhesive film, and the convex portion of the mold is in contact with the element arrangement region. A molded body is formed on one surface of the wiring member with a pair of molds opposed to each other via an adhesive film. Thereby, each wiring member which opposes via an adhesive film will be pressed toward the adhesive film side by the metal mold | die and a molded object (thermosetting resin composition) from the said one surface side, and a molded object ( The stress caused by the difference in coefficient of linear expansion between the thermosetting resin composition) and the wiring member is offset and relaxed. Such relaxation of stress can suppress the occurrence of warpage in the substrate for mounting an optical semiconductor element, and can suppress a decrease in productivity. Further, since the deformation of the substrate for mounting the optical semiconductor element is suppressed in this way and the pair of molds are opposed so that the convex part of the mold is in contact with the element arrangement region of the wiring member, the wiring member and the mold The occurrence of dirt between the two is suppressed. Thereby, the connection defect of an optical semiconductor element and a wiring member can be suppressed, suppressing the fall of productivity, without requiring the process of removing dirt separately.

  The method for manufacturing an optical semiconductor element mounting substrate according to the present invention includes a film adhering step of adhering one surface of an adhesive film to each of the other surfaces of the wiring member before the wiring member arranging step, and the wiring member arranging step. It is preferable that the other surfaces of the adhesive film are bonded together. In this case, generation | occurrence | production of the connection defect of an optical semiconductor element and the curvature of a board | substrate can further be suppressed, suppressing further the fall of productivity.

  The method for manufacturing an optical semiconductor element mounting substrate according to the present invention includes a film adhering step for adhering the other surface of each of the wiring members to the same surface of the adhesive film before the wiring member arranging step. It is preferable that the adhesive film is folded back so that the other surfaces of the wiring members are opposed to each other with the adhesive film interposed therebetween. In this case, generation | occurrence | production of the connection defect of an optical semiconductor element and the curvature of a board | substrate can further be suppressed, suppressing further the fall of productivity.

  In the method for manufacturing an optical semiconductor element mounting substrate according to the present invention, in the wiring member arranging step, it is preferable that the other surface of the wiring member is bonded to each of both surfaces of the adhesive film having adhesiveness on both surfaces. In this case, generation | occurrence | production of the connection defect of an optical semiconductor element and the curvature of a board | substrate can further be suppressed, suppressing further the fall of productivity.

  A substrate for mounting an optical semiconductor element according to the present invention is manufactured by the above-described method for manufacturing a substrate for mounting an optical semiconductor element, the molded body has a plurality of cavity portions, and a thermosetting resin composition having light reflectivity. At least the inner peripheral side surface of the cavity portion is formed by the object.

  Since the optical semiconductor element mounting substrate according to the present invention is manufactured by the above-described optical semiconductor element mounting substrate manufacturing method, the optical semiconductor element connection failure and the warpage of the substrate occur while suppressing the decrease in productivity. Can be suppressed.

  An optical semiconductor device manufacturing method according to the present invention includes: an optical semiconductor element disposing step of disposing an optical semiconductor element in each of the cavity portions of the optical semiconductor element mounting substrate; and transmitting light to the cavity portion so as to cover the optical semiconductor element. A sealing resin filling step of filling a sealing resin having a property, and a dividing step of obtaining a plurality of optical semiconductor devices by dividing the molded body for each cavity portion.

  In the method of manufacturing an optical semiconductor device according to the present invention, since the optical semiconductor element mounting substrate is used, the optical semiconductor element connection failure and the occurrence of warping of the substrate are suppressed while suppressing a decrease in productivity. be able to.

  In the dividing step, it is preferable to divide the formed body by dicing. In this case, the molded body can be divided with high productivity.

  The optical semiconductor device according to the present invention is manufactured by the above-described method for manufacturing an optical semiconductor device.

  In the optical semiconductor device according to the present invention, the optical semiconductor device is manufactured by the method for manufacturing an optical semiconductor device, so that it is possible to suppress the occurrence of poor connection of the optical semiconductor element and the warpage of the substrate while suppressing the decrease in productivity. .

  ADVANTAGE OF THE INVENTION According to this invention, the optical semiconductor element mounting board | substrate which can suppress generation | occurrence | production of the connection failure of an optical semiconductor element, and generation | occurrence | production of the curvature of a board | substrate, suppressing the fall of productivity, and its optical semiconductor device And a manufacturing method thereof.

1 is a perspective view showing an embodiment of an optical semiconductor device according to the present invention. 1 is a schematic cross-sectional view showing an embodiment of an optical semiconductor device according to the present invention. It is a schematic cross section which shows other one Embodiment of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows other one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention. It is a schematic cross section which shows other one Embodiment of the manufacturing method of the optical semiconductor device which concerns on this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

(Optical semiconductor device)
FIG. 1 is a perspective view showing an embodiment of an optical semiconductor device according to the present invention. FIG. 2 is a schematic cross-sectional view showing an embodiment of an optical semiconductor device according to the present invention. FIG. 3 is a schematic cross-sectional view showing another embodiment of the optical semiconductor device according to the present invention.

  As shown in FIGS. 1 and 2, the optical semiconductor device 100 includes an optical semiconductor element mounting substrate 10, an optical semiconductor element 20, and a sealing resin portion 30. In addition, illustration of the sealing resin part 30 is abbreviate | omitted in FIG.

  The optical semiconductor element mounting substrate 10 is a pre-molded package substrate, and includes a wiring member 12 having a front surface (one surface) 12a and a back surface (other surface) 12b opposite to the front surface 12a, and a front surface 12a of the wiring member 12. And a reflector (light reflecting layer) 14 disposed thereon.

  Although it does not specifically limit as the wiring member 12, At least 1 sort (s) chosen from a lead frame, a printed wiring board, a flexible wiring board, and a metal base wiring board can be used. The lead frame can be obtained by forming a circuit on a substrate such as copper or 42 alloy using a known method.

  The wiring member 12 includes, for example, a pair of wiring portions, and has a flat plate structure in which a line between the wiring portions is filled with a cured product layer 16 of a thermosetting resin composition. In the case of a light emitting device such as an LED, conductor layers 18a and 18b are formed on the surface of the wiring portion by, for example, silver plating or nickel / silver plating so that the light from the optical semiconductor element 20 can be efficiently reflected. It is preferable. The conductor layer 18a is formed on one wiring portion, and the conductor layer 18b is formed on the other wiring portion.

  The reflector 14 is a plate-like molded body, and one through hole is formed in the center from the front surface to the back surface. In the optical semiconductor element mounting substrate 10, a cavity (recess) 14 a is formed by closing the through hole of the reflector 14 with the wiring member 12. A region on the surface 12a located on the bottom surface of the cavity portion 14a is an optical semiconductor element mounting region (element mounting region).

  The reflector 14 includes a cured product of a thermosetting resin composition having light reflectivity. The reflector 14 is preferably formed entirely by a light-reflective thermosetting resin composition, but at least the inner peripheral side surface of the cavity portion 14a is formed by a light-reflective thermosetting resin composition. It only has to be. The thermosetting resin composition having light reflectivity includes, for example, (A) an epoxy resin, (B) a curing agent and (C) a thermosetting resin containing a curing accelerator, (D) an inorganic filler, E) A resin composition obtained by mixing and kneading a white pigment and (F) a coupling agent.

  The (A) epoxy resin is not particularly limited as long as it is generally used as an epoxy resin molding material for sealing electronic components. (A) Epoxy resins include, for example, epoxidized phenol and aldehyde novolak resins such as phenol novolac type epoxy resins and orthocresol novolak type epoxy resins, bisphenol A, bisphenol F, bisphenol S and alkyl-substituted biphenols. Glycidylamine type epoxy resins obtained by reaction of polyamines such as diglycidyl ether, diaminodiphenylmethane and isocyanuric acid with epichlorohydrin, linear aliphatic epoxy resins obtained by oxidizing olefinic bonds with peracids such as peracetic acid, Moreover, an alicyclic epoxy resin etc. are mentioned. These may be used alone or in combination of two or more.

  (A) As for an epoxy resin, a thing with comparatively little coloring is preferable. Examples of such an epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and triglycidyl isocyanurate.

  (B) The curing agent can be used without particular limitation as long as it reacts with (A) the epoxy resin, but those with relatively little coloring are preferred. (B) As a hardening | curing agent, an acid anhydride type hardening | curing agent, a phenol type hardening | curing agent, etc. are mentioned, for example. 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. Examples include acid, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and the like. Among these acid anhydride curing agents, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride are preferably used. Examples of phenolic curing agents include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and / or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene, and formaldehyde. A resin obtained by condensing or co-condensing a compound having an aldehyde group such as an acid catalyst, a phenol / aralkyl resin synthesized from phenols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl, Examples include aralkyl type phenol resins such as naphthol / aralkyl resins. These curing agents may be used alone or in combination of two or more. The acid anhydride curing agent preferably has a weight average molecular weight of about 140 to 200, and is preferably colorless or light yellow.

  The content of the (B) curing agent is such that the proportion of the active group (an acid anhydride group or hydroxyl group) capable of reacting with the epoxy group in the (B) curing agent is equivalent to 1 equivalent of the epoxy group in the (A) epoxy resin. It is preferably 0.5 to 1.5 equivalents, and more preferably 0.7 to 1.2 equivalents. When the ratio of the active group is less than 0.5 equivalent, the curing rate of the thermosetting resin composition is slow, and the glass transition temperature of the resulting cured product tends to be low. When exceeding, there exists a tendency for the moisture resistance of hardened | cured material to fall.

  (C) Although it does not specifically limit as a hardening accelerator (curing catalyst), For example, 1,8- diaza-bicyclo (5,4,0) undecene-7, a triethylenediamine, a tri-2,4. Tertiary amines such as 2,6-dimethylaminomethylphenol, imidazoles such as 2-ethyl-4-methylimidazole and 2-methylimidazole, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetra-n-butylphosphonium- Examples thereof include phosphorus compounds such as o, o-diethyl phosphorodithioate, quaternary ammonium salts, organometallic salts, and derivatives thereof. These may be used alone or in combination of two or more. Among these curing accelerators, it is preferable to use tertiary amines, imidazoles, and phosphorus compounds.

  (C) 0.01-8.0 mass parts is preferable with respect to 100 mass parts of (A) epoxy resins, and, as for content of a hardening accelerator, 0.1-3.0 mass parts is more preferable. (C) If the content of the curing accelerator is less than 0.01 parts by mass, there is a tendency that a sufficient curing acceleration effect cannot be obtained. If the content exceeds 8.0 parts by mass, the resulting cured product is discolored. Tend to be.

  (D) As an inorganic filler, a silica is mentioned, for example. (D) As the inorganic filler, from the viewpoint of excellent thermal conductivity, light reflection characteristics, moldability, and flame retardancy, silica, among the (E) white pigment alumina described later, antimony oxide, aluminum hydroxide It is preferable that it is a mixture containing 2 or more types.

  (D) Although the center particle diameter of an inorganic filler is not specifically limited, It is preferable that it is the range of 1-100 micrometers from a viewpoint of improving the packing efficiency with (E) white pigment. A plurality of (D) white pigments having different center particle diameters may be added from the viewpoint of excellent thermal conductivity and light reflection characteristics.

  Examples of (E) white pigments include titanium oxide, alumina, magnesium oxide, antimony oxide, aluminum hydroxide, barium sulfate, magnesium carbonate, barium carbonate, and inorganic hollow particles. (E) As the white pigment, alumina, magnesium oxide, inorganic hollow particles, or a mixture thereof is preferable from the viewpoint of excellent thermal conductivity and light reflection characteristics. Examples of the inorganic hollow particles include sodium silicate glass, aluminum silicate glass, borosilicate soda glass, and shirasu. These may be used alone or in combination of two or more.

  (E) The center particle diameter of the white pigment is preferably in the range of 0.1 to 50 μm. If the center particle size is less than 0.1 μm, the particles tend to aggregate and the dispersibility tends to deteriorate, and if it exceeds 50 μm, the reflection characteristics tend not to be sufficiently obtained.

  The total content of (D) inorganic filler and (E) white pigment is preferably in the range of 75 to 95 mass% with respect to the entire thermosetting resin composition. If the total content is less than 75% by mass, thermal conductivity and light reflection characteristics tend to be insufficient, and if it exceeds 95% by mass, the moldability of the resin composition deteriorates, and an optical semiconductor element. There is a tendency that the production of the mounting substrate becomes difficult.

  (F) Although it does not specifically limit as a coupling agent, For example, a silane coupling agent, a titanate coupling agent, etc. can be used. As the silane coupling agent, for example, epoxy silane, amino silane, cationic silane, vinyl silane, acryl silane, mercapto silane, and composites thereof can be used. (F) The processing conditions for the coupling agent are not particularly limited. (F) It is preferable that content of a coupling agent is 5 mass% or less with respect to the whole thermosetting resin composition.

  Moreover, you may add additives, such as antioxidant, a mold release agent, and an ion supplement agent, to a thermosetting resin composition as needed.

  The optical semiconductor element 20 is disposed on the conductor layer 18a via a die bond material (not shown) in the optical semiconductor element mounting region in the cavity portion 14a. The optical semiconductor element 20 is electrically connected to the conductor layer 18 b by a bonding wire 40. As shown in FIG. 3, the optical semiconductor element 20 may be electrically connected to each of the conductor layers 18a and 18b by solder bumps 42 without using bonding wires. The optical semiconductor element 20 is not limited to being arranged in the cavity portion 14a, and a plurality of optical semiconductor elements 20 may be arranged.

  The sealing resin part 30 is filled in the cavity part 14 a and seals the optical semiconductor element 20. The sealing resin part 30 is formed of a transparent sealing resin having translucency. As the transparent sealing resin, for example, a mixture of an epoxy resin and an acid anhydride is used. A phosphor 30 a such as a YAG (yttrium, aluminum, garnet) phosphor is dispersed in the sealing resin portion 30.

(Manufacturing method of optical semiconductor device)
Next, a method for manufacturing the optical semiconductor device 100 will be described. The manufacturing method of the optical semiconductor device 100 includes an optical semiconductor element mounting substrate manufacturing process, an optical semiconductor element arranging process, a sealing resin filling process, and a dividing process.

  First, an optical semiconductor element mounting substrate manufacturing process will be described with reference to FIGS. 4 to 7 are schematic cross-sectional views showing an embodiment of a method for manufacturing an optical semiconductor device according to the present invention. The manufacturing method of the optical semiconductor element mounting substrate 10 includes a film adhering step, a wiring member arranging step, a mold arranging step, a molded body forming step, a die removing step, and an adhesive film peeling step.

  In the film bonding step, first, a plurality of wiring members 12 and a pair of adhesive films 50 are prepared. The wiring member 12 can be obtained from a metal foil by a known method such as punching or etching. Next, the wiring members 12 are arranged in a matrix so that the optical semiconductor device mounting regions are separated from each other at a predetermined interval, and the adhesive film 50 is formed on each back surface 12b of the wiring member 12 as shown in FIG. The surface (one surface) 50a is bonded.

  As for the adhesive film 50, at least the surface 50a should just have adhesiveness, and both surfaces of the surface 50a and the back surface (other side) 50b may have adhesiveness. The adhesive film 50 has the same shape (for example, thickness, area) and the same physical properties (for example, the same) from the viewpoint of further suppressing the occurrence of poor connection of the optical semiconductor element 20 and warping of the substrate by applying pressure equally from both sides. It is preferable to have a linear expansion coefficient.

  The adhesive film 50 is not particularly limited as long as it is an adhesive film, but may be a film that is resistant to the molding temperature, the heating temperature at the time of optical semiconductor element mounting, and wire bonding. preferable. As the adhesive film 50, when a substrate having a large area is used as in MAP molding, it is preferable to use a film with little dimensional change during heating. Since the adhesive film 50 is clamped in the mold together with the wiring member 12 in the molding process, a large deformation or distortion occurs with respect to the clamp pressure from the viewpoint of further suppressing the occurrence of dirt such as flash. A film having a certain degree of elasticity is preferred. Examples of the material of the adhesive film 50 that satisfies these purposes include polyimide resin.

  In the wiring member arranging step, the back surfaces 12b of the wiring member 12 are opposed to each other with the adhesive film 50 interposed therebetween. In the wiring member arranging step, for example, as shown in FIG. 4B, the back surfaces 12b of the wiring members 12 are opposed to each other by bonding the back surfaces 50b of the adhesive film 50 together. In this case, the wiring member 12 has the same shape (for example, thickness, area) and physical properties (for example, from the viewpoint of further suppressing the occurrence of connection failure of the optical semiconductor element 20 and warping of the substrate by applying pressure equally from both sides. For example, it preferably has a hardness and a linear expansion coefficient, and is preferably arranged at positions symmetrical to each other via the adhesive film 50.

  After the wiring member placement step, a mold placement step is performed. In the mold placement step, a mold 52 having a plurality of recesses 52a filled with the thermosetting resin composition and a plurality of projections 52b serving as the cavity portions 14a in which the optical semiconductor element 20 is placed in the molded body. Is used. For example, the recesses 52a are arranged in a matrix so as to coincide with the arrangement interval of the optical semiconductor device mounting region of the wiring member 12, and the protrusions 52b are interposed between the recesses 52a. The mold 52 is preferably clamped so that the upper mold and the lower mold are aligned symmetrically for the purpose of further relieving the stress generated when clamping the two wiring members with adhesive films.

  The mold 52 has a resin inlet 52c through which the thermosetting resin composition can flow. The width and depth of the gate serving as the resin injection port 52c and the runner serving as the resin flow path are uniform between the wiring members 12 facing each other with the pressure applied to the wiring member 12 in the recess 52a of the mold 52 after the resin injection is started. It is preferable that it is designed to be.

  In the mold placement step, as shown in FIG. 5A, the wiring member 12 and the adhesive film 50 are placed so that the convex portion 52b of the mold 52 contacts the optical semiconductor element mounting region on the surface 12a of the wiring member 12. The pair of molds 52 are opposed to each other and clamped. At this time, the convex portions 52 b of the pair of molds 52 are arranged to face each other with the wiring member 12 and the adhesive film 50 interposed therebetween. The recesses 52a of the pair of molds 52 are aligned on the respective surfaces 12a of the wiring member 12 so that the inner peripheral side surfaces surround the optical semiconductor element mounting region.

  The pair of molds 52 has the same shape (for example, thickness, area) and physical properties (for example, hardness) from the viewpoint of further suppressing the occurrence of poor connection of the optical semiconductor element 20 and warping of the substrate by applying pressure evenly from both sides. , Linear expansion coefficient). The pair of molds 52 are preferably arranged so as to be symmetrical with each other via the wiring member 12 and the adhesive film 50 so that the concave portions 52a and the convex portions 52b are symmetrical with each other. The relative position of the wiring member 12 and the mold 52 is fixed by the alignment pin 54.

  In the molded body forming step, as shown in FIG. 5B, the recess 52a is filled with a thermosetting resin composition, and a molded body that becomes the reflector 14 is formed on the surface 12a of the wiring member 12 by transfer molding. At this time, the space between the wiring portions of the wiring member 12 is also filled with the thermosetting resin composition to form the cured product layer 16. The thermosetting resin composition is injected into the mold 52 through the resin injection port 52c. In transfer molding, the wiring member 12 is pressed in the thickness direction by the thermosetting resin composition injected into the mold 52 and the mold 52. In the transfer molding, for example, the thermosetting resin composition is thermoset under conditions of a mold temperature of 170 to 190 ° C. for 60 to 120 seconds and an after cure temperature of 120 to 180 ° C. for 1 to 3 hours to obtain a cured product. obtain.

  By the way, when a QFN structure package is molded, the thermosetting resin composition injected into the mold 52 may wrap around the back surface 12b of the wiring member 12 in the molded body forming step. In this case, defects such as burrs occur. However, in the said manufacturing method, the adhesive film 50 becomes an adhesive film for back surface protection by adhere | attaching the adhesive film 50 on the back surface 12b of the wiring member 12, and it can suppress the surroundings of a resin composition.

  The thermosetting resin composition can be obtained by uniformly dispersing and mixing (A) various components such as an epoxy resin, but means and conditions for dispersing and mixing are not particularly limited. As a general method for producing a thermosetting resin composition, there can be mentioned a method in which each component is kneaded with an extruder, a kneader, a roll, an extruder, etc., and then the kneaded product is cooled and pulverized. When kneading each component, it is preferable to carry out in a molten state from the viewpoint of improving dispersibility. The kneading conditions may be appropriately determined depending on the type and blending amount of each component. For example, kneading is preferably performed at 15 to 100 ° C. for 5 to 40 minutes, and kneading at 20 to 100 ° C. for 10 to 30 minutes is more preferable. preferable. When the kneading temperature is less than 15 ° C., it becomes difficult to knead each component and the dispersibility also tends to decrease. When the kneading temperature exceeds 100 ° C., the resin composition increases in molecular weight, and the resin composition is cured. There is a possibility that. If the kneading time is less than 5 minutes, resin burrs may be generated during transfer molding. If the kneading time exceeds 40 minutes, the resin composition may be increased in molecular weight and the resin composition may be cured.

  After the molded body forming step, a mold removing step is performed. In the mold removing step, as shown in FIG. 6A, the mold 52 is removed from the surface 12a of the wiring member 12, and the alignment pins 54 are removed.

  An adhesive film peeling process is performed after a metal mold | die removal process. In the adhesive film peeling step, as shown in FIG. 6B, the adhesive film 50 is removed from the back surface 12b of the wiring member 12 to obtain the wiring member 12 on which the reflector 14 is formed.

  Thus, the optical semiconductor element mounting substrate 10 in which a plurality of cavities are formed is obtained.

  After the optical semiconductor element mounting substrate manufacturing process, an optical semiconductor element arrangement process is performed. In the optical semiconductor element arranging step, first, conductor layers 18a and 18b are formed on the surface 12a of the wiring member 12 exposed from the bottom surface of the cavity portion. Next, the optical semiconductor element 20 is disposed on each conductor layer 18a in the cavity portion 14a.

  Next, the optical semiconductor element 20 and the conductor layer 18b are electrically connected. For example, as shown in FIG. 7A, the optical semiconductor element 20 and the conductor layer 18 b are electrically connected by a bonding wire 40. In addition, as shown in FIG. 3, the solder bumps 42 may be formed on the conductor layers 18 a and 18 b before the optical semiconductor element 20 is disposed, and the optical semiconductor element 20 may be disposed on the solder bump 42.

  After the optical semiconductor element arranging step, a sealing resin filling step is performed. In the sealing resin filling step, as shown in FIG. 7A, the cavity resin is filled with a light-transmitting sealing resin so as to cover the optical semiconductor element 20, thereby forming the sealing resin portion 30. For example, potting can be used for filling the resin.

  After the sealing resin filling step, a dividing step is performed. In the dividing step, as shown in FIG. 7 (b), the formed body in which the plurality of reflectors 14 are connected is divided into individual cavities. In the dividing step, for example, the molded body is separated into single bodies by dicing from two directions orthogonal to each other in a horizontal direction on the surface of the molded body. The dividing method is not limited to this, and known methods such as laser processing, water jet processing, and die processing can be used. Through the above steps, a plurality of optical semiconductor devices 100 are obtained.

  In the method for manufacturing the optical semiconductor device 100, the wiring members 12 are arranged such that the back surfaces 12b of the wiring members 12 are opposed to each other through the adhesive film 50, and the convex portions 52b of the mold 52 are in contact with the optical semiconductor element mounting region. In addition, a pair of molds 52 are opposed to each other via the adhesive film 50, and a molded body that becomes the reflector 14 is formed on the surface 12 a of the wiring member 12. Thereby, each wiring member 12 which opposes via the adhesive film 50 will be pressed toward the adhesive film 50 side by the metal mold | die 52 and a molded object (thermosetting resin composition) from the surface 12a side, The stress caused by the difference in the coefficient of linear expansion between the molded body (thermosetting resin composition) and the wiring member 12 is offset and relaxed. Such relaxation of stress can suppress the occurrence of warpage in the optical semiconductor element mounting substrate 10 and can suppress a reduction in productivity.

  Also, the deformation of the optical semiconductor element mounting substrate 10 is suppressed in this way, and the pair of molds 52 are opposed so that the convex portion 52b of the mold 52 contacts the optical semiconductor element mounting region of the wiring member 12. Therefore, the occurrence of dirt between the wiring member 12 and the mold 52 is suppressed. Thereby, the connection defect of the optical semiconductor element 20 and the wiring member 12 can be suppressed, suppressing the fall of productivity, without requiring the process of removing dirt separately.

  Moreover, in the manufacturing method of the optical semiconductor device 100, since the optical semiconductor element mounting substrate 10 can be obtained on both sides of the adhesive film 50, the optical semiconductor device 100 can be obtained efficiently and at low cost.

  The optical semiconductor element mounting substrate manufacturing process is not limited to the above process. As shown in FIG. 8, after the respective back surfaces 12b of the wiring members 12 are bonded to the same surface of the adhesive film 50 in the film bonding step, the adhesive film 50 is folded back in the wiring member placement step, so that the back surface 12b of the wiring member 12 is returned. They may be opposed to each other with the adhesive film 50 interposed therebetween. Even when the optical semiconductor device 100 is obtained by such a process, it is possible to suppress the occurrence of poor connection of the optical semiconductor element 20 and the warpage of the substrate while suppressing a decrease in productivity. Further, in the film bonding step, the wiring members 12 facing each other when the adhesive film 50 is folded back are positioned symmetrically so that the adjacent wiring members 12 are arranged at predetermined intervals from each other. It is preferable to adhere the member 12 to the adhesive film 50.

  Further, as shown in FIG. 9, in the wiring member placement step, the back surface 12b of the wiring member 12 is bonded to each of both surfaces of the adhesive film 50 in which both the front surface 50a and the back surface 50b are adhesive, and the back surface of the wiring member 12 The wiring member 12 may be arranged so that 12b face each other with the adhesive film 50 interposed therebetween. Even when the optical semiconductor device 100 is obtained by such a process, it is possible to suppress the occurrence of poor connection of the optical semiconductor element 20 and the warpage of the substrate while suppressing a decrease in productivity. Furthermore, in the wiring member arrangement step, it is preferable that each wiring member 12 is bonded to the adhesive film 50 so that the wiring members 12 facing each other through the adhesive film 50 are positioned symmetrically.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

Example 1
[Fabrication of optical semiconductor device]
<Preparation of thermosetting resin composition for light reflection>
Each blending component was blended in the blending amounts shown in Table 1, sufficiently kneaded with a mixer, and then melt-kneaded with a mixing roll at 40 ° C. for 15 minutes to obtain a mixture. After cooling this mixture, it was pulverized to obtain a thermosetting resin composition for light reflection. In addition, the unit of the compounding quantity of each component in Table 1 is a mass part.

In Table 1, * 1 to 8 are as follows.
* 1: Trisglycidyl isocyanurate (epoxy equivalent 100, manufactured by Nissan Chemical Co., Ltd., trade name: TEPIC-S)
* 2: Hexahydrophthalic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.)
* 3: Tetra-n-butylphosphonium-o, o-diethyl phosphorodithioate (manufactured by Nippon Chemical Industry Co., Ltd., trade name: PX-4ET)
* 4: Trimethoxyepoxysilane (manufactured by Toray Dow Corning, trade name: A-187)
* 5: Fused silica (manufactured by Denki Kagaku Kogyo, trade name: FB-950)
* 6: Fused silica (manufactured by Admatechs, trade name: SO-25R)
* 7: Titanium oxide (made by Sakai Chemical Industry Co., Ltd., trade name: FTR-700)
* 8: Hollow particles (manufactured by Sumitomo 3M, trade name: S60-HS)

<Fabrication of optical semiconductor element mounting substrate>
First, as the wiring member, a plurality of 0.25 μm thick copper lead frames whose surfaces were Ag-plated were prepared. An optical semiconductor element mounting region was formed on the surface of each lead frame so as to form a pattern having a pair of cathode and anode.

  Next, the lead frames were arranged in a matrix so that the optical semiconductor device mounting areas were separated from each other by a predetermined interval, and the surface of the back surface protective adhesive film was adhered to the back surface of each of the lead frames. As the adhesive film for protecting the back surface, two batch sealing molding tapes (made by Hitachi Chemical Co., Ltd., trade name: RT-521) having adhesiveness on the front and back surfaces were used.

  Subsequently, the back surfaces of the adhesive film with a lead frame were bonded to each other. In this case, the optical semiconductor element mounting region of the lead frame was aligned so as to be symmetrical with each other via the pair of back surface protective adhesive films.

  Next, molding dies were respectively disposed on the surfaces of the pair of lead frames. As the molding die, a die having a plurality of concave portions arranged in a matrix so as to coincide with the arrangement interval of the optical semiconductor device mounting region of the lead frame and a plurality of convex portions interposed between the concave portions was used. . The pair of molds were arranged and clamped at positions symmetrical to each other via the lead frame and the adhesive film so that the convex portions of the mold contacted the optical semiconductor element mounting region of the lead frame. In that case, the positioning pin was installed and it was considered that the paired lead frame with the adhesive film for protecting the back surface would not be displaced during molding. The width and depth of the gate serving as the resin injection port into the cavity and the runner serving as the resin flow path were designed so that the pressure on both sides applied to the lead frame in the cavity was uniform after the resin injection was started.

  Next, a molded body was formed on the surface of the lead frame by transfer molding, and a cured product layer was formed in a gap between wiring portions in the wiring member. After filling the inside of the molding die with the thermosetting resin composition for light reflection, the resin composition was cured. As the transfer molding machine, ATOM-FX (trade name) manufactured by MTEX was used. The molding conditions were a mold temperature of 180 ° C., a clamp pressure of 20 t, an injection pressure of 7 MPa, and a molding time of 90 seconds.

  After forming the molded body, the molding die and the alignment pin were removed. Further, the adhesive film was peeled off from each wiring member to obtain an optical semiconductor element mounting substrate on which a plurality of cavities were formed.

<Mounting of optical semiconductor elements>
Nickel / silver plating was applied to the anode and cathode of each optical semiconductor element mounting region on the optical semiconductor element mounting substrate to form a pair of conductor layers (terminals). Next, after apply | coating the die-bonding material on one conductor layer, the optical semiconductor element was arrange | positioned on the die-bonding material. Subsequently, the optical semiconductor element (LED element) was fixed by heating at 150 ° C. for 1 hour. Thereafter, the surface of the optical semiconductor element and the other conductor layer were electrically connected with a gold wire.

<Encapsulation of optical semiconductor element>
Next, a transparent sealing resin having the following resin composition was poured into the cavity of the optical semiconductor element mounting substrate on which the optical semiconductor element was mounted, thereby sealing the optical semiconductor element. After potting, the transparent sealing resin was cured by heating at 150 ° C. for 2 hours.
(Resin composition)
・ Hydrogenated bisphenol A type epoxy resin, Denacol EX252 (manufactured by Nagase ChemteX Corporation), 90 parts by mass Anhydride, HN-5500E (manufactured by Hitachi Chemical), 90 parts by mass, 2,6-di-tert-butyl-4-methylphenol (BHT), 0.4 parts by mass, 2-ethyl-4-methylimidazole, 0.9 parts by mass

<Dicing>
After the transparent sealing resin was cured, the optical semiconductor element mounting substrate was separated into individual cavities by dicing to obtain a plurality of optical semiconductor devices.

[Evaluation of optical semiconductor devices]
In the optical semiconductor device obtained in Example 1, no warpage was observed when a molded body was produced by transfer molding using a thermosetting light reflecting resin. Further, the occurrence of resin contamination due to resin burrs was not confirmed, and connection failure could be suppressed without requiring a deburring step. As described above, in Example 1, an optical semiconductor device could be obtained with high productivity.

(Comparative Example 1)
As a wiring member, one lead frame similar to that in Example 1 was prepared. Next, a mold (lower mold) that covers the entire back surface of the lead frame, a plurality of concave portions arranged in a matrix, and a plurality of convex portions interposed between the concave portions, are provided on the surface of the lead frame Using the mold (upper mold) to be arranged, the upper mold and the lower mold were respectively arranged on the lead frame so that the convex portion of the upper mold was in contact with the optical semiconductor element mounting region. Subsequently, the same thermosetting resin composition as in Example 1 was filled in the concave portion of the upper mold, and a molded body was formed on the surface of the lead frame by transfer molding.

  In Comparative Example 1, it was confirmed that the optical semiconductor element mounting substrate was warped. Further, as a result of filling the resin composition into the recess, the optical semiconductor element mounting substrate is deformed, so that the resin composition flows into the gap between the optical semiconductor element mounting area and the upper mold convex part, and the optical semiconductor element mounting area Resin soiling occurred. Since warping and resin contamination occurred in this way, post-processes such as mounting of an optical semiconductor element could not be performed, and an optical semiconductor device could not be obtained.

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate for optical semiconductor element mounting, 12 ... Wiring member, 12a ... The surface (one side) of a wiring member, 12b ... The back surface (other side) of a wiring member, 14 ... Reflector (molded object), 14a ... Cavity part, 20 DESCRIPTION OF SYMBOLS ... Optical semiconductor element, 30 ... Sealing resin part, 50 ... Adhesive film, 50a ... Adhesive film surface (one side), 50b ... Adhesive film back surface (other side), 52 ... Mold, 52a ... Mold concave part 52b, convex portions of the mold, 100, an optical semiconductor device.

Claims (6)

A method for manufacturing an optical semiconductor element mounting substrate using a mold having a concave portion filled with a thermosetting resin composition and a convex portion serving as a cavity in which an optical semiconductor element is arranged in a molded body. ,
A wiring member placement step in which the other surfaces of the wiring member having an element placement region on one side where the optical semiconductor element is placed are opposed to each other via an adhesive film;
A mold placement step of causing a pair of molds to face each other via the wiring member and the adhesive film so that the convex portion comes into contact with the element placement region;
And a molded body forming step of filling the recess with the thermosetting resin composition and forming the molded body on the one surface of the wiring member by transfer molding. . Before the wiring member placement step, comprising a film bonding step of bonding one surface of the adhesive film to each other surface of the wiring member,
The method for manufacturing a substrate for mounting an optical semiconductor element according to claim 1, wherein in the wiring member arranging step, the other surfaces of the adhesive film are bonded together. Before the wiring member placement step, comprising a film bonding step of bonding the other surface of the wiring member to the same surface of the adhesive film,
The method for manufacturing a substrate for mounting an optical semiconductor element according to claim 1, wherein, in the wiring member arranging step, the adhesive film is folded back so that the other surfaces of the wiring member are opposed to each other through the adhesive film.   2. The method for manufacturing a substrate for mounting an optical semiconductor element according to claim 1, wherein, in the wiring member arranging step, the other surface of the wiring member is bonded to each of the both surfaces of the adhesive film having adhesiveness on both surfaces. A step of manufacturing an optical semiconductor element mounting substrate by the method for manufacturing an optical semiconductor element mounting substrate according to any one of claims 1 to 4,
An optical semiconductor element arranging step of arranging the optical semiconductor element to each of the cavity portion of the optical element mounting substrate,
A sealing resin filling step of filling the cavity part with a light-transmitting sealing resin so as to cover the optical semiconductor element;
A dividing step of dividing the molded body into the cavity portions to obtain a plurality of optical semiconductor devices. The method for manufacturing an optical semiconductor device according to claim 5 , wherein in the dividing step, the molded body is divided by dicing.

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