JP2014022651A - Optical semiconductor device, manufacturing method of the same, base substrate and reflector mold used for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical semiconductor device which can inhibit sulfidation of a silver plating layer, and provide a manufacturing method of the optical semiconductor device, a base substrate and a reflector mold used of manufacturing of the optical semiconductor device.SOLUTION: An optical semiconductor device 1A comprises: a substrate 10 on which a silver plating layer 14 is formed on a surface; a blue LED 30 bonded on the silver plating layer 14; a reflector 20 arranged on the substrate 10 at a position to surround the blue LED 30; a transparent encapsulation resin 40 filled in the reflector 20 for encapsulating the blue LED 30; and a mica film 50 which covers the silver plating layer 10. A thickness of the mica film is not less than 0.005 μm and not more than 500 μm. Because in this optical semiconductor device 1A, the silver plating layer 14 is covered with the mica film 50 and the film thickness d of the mica film 50 is within a range of not less than 0.005 μm and not more than 500 μm, sulfidation of the silver plating layer 14 can be inhibited to a practically sufficient degree. Accordingly, decrease in illumination intensity of the optical semiconductor device 1A caused by blackening of the silver plating layer 14 is inhibited.

Description

  The present invention relates to an optical semiconductor device in which a light emitting diode is bonded onto a silver plating layer formed on a surface of a substrate, a manufacturing method thereof, a base body used for the manufacturing, and a reflector molded body.

  As an optical semiconductor device on which an LED (Light Emitting Diode) is mounted, the one disclosed in Patent Document 1 is known. The optical semiconductor device described in Patent Document 1 is formed by bonding a blue LED to a molded body, raising the molded body so as to surround the blue LED, and reflecting the light emitted from the blue LED. The blue LED is sealed by filling a transparent sealing portion containing a body.

International Publication No. 2007/015426 Pamphlet

  In recent years, such optical semiconductor devices have come to be employed as LED lighting such as lighting and street lamps. However, when actually used, the illuminance of the LED illumination decreases in a shorter time than the guaranteed time of the LED. This is because a silver plating layer is formed on the electrode of the optical semiconductor device and the silver plating layer is discolored. That is, since the resin having high gas and moisture permeability is generally used for the transparent sealing portion, the silver plating layer is corroded and discolored by the gas and moisture that have passed through the transparent sealing portion. In particular, when the silver plating layer is sulfided by hydrogen sulfide gas, the electrode is changed to black, so that the illuminance is significantly reduced.

  Conventionally, a thermoplastic resin has been employed as the reflecting plate, and since the yellowing rate of the reflecting plate was faster than the sulfiding rate of the silver plating layer, the decrease in illuminance due to the sulfidation of the silver plating layer was not noticeable. However, recently, a thermosetting resin has been adopted as a reflection plate, and the yellowing rate of the reflection plate has become slower than the sulfidation rate of the silver plating layer. It has come to stand out. In addition, when the LED illumination is made high-powered, the heat generation temperature of the blue LED is increased and the temperature of the silver plating layer is increased, so that the sulfidation of the silver plating layer is promoted.

  Furthermore, in view of such problems associated with the sulfidation of the silver plating layer, there is a movement to standardize the evaluation of the hydrogen sulfide resistant gas of the optical semiconductor device adopted for the LED illumination.

  Therefore, the present inventors have conducted intensive studies and found that the silver plating layer was effectively covered with the mica film rather than improving the gas permeability of the transparent sealing portion, thereby effectively sulfiding the silver plating layer. It was found that it can be suppressed.

  However, according to the thickness of the mica film covering the silver plating layer, the degree of suppression of sulfidation of the silver plating layer changes. Research on thickness range was repeated.

  That is, an object of the present invention is to provide an optical semiconductor device capable of suppressing the sulfidation of the silver plating layer to a practically sufficient level, a manufacturing method thereof, a substrate used for the manufacturing, and a reflector molded body.

  An optical semiconductor device according to the present invention includes a substrate having a silver plating layer formed on a surface thereof, a light emitting diode bonded on the silver plating layer, and a reflector disposed on the substrate so as to surround the light emitting diode. The transparent sealing portion that fills the reflector and seals the light emitting diode and the mica film that covers the silver plating layer have a thickness of 0.005 μm to 500 μm.

  In this optical semiconductor device, the silver plating layer is covered with a mica film, and the film thickness of the mica film is in the range of 0.005 μm to 500 μm. Sulfurization can be suppressed. As a result, a decrease in illuminance of the optical semiconductor device due to blackening of the silver plating layer is suppressed.

  A substrate according to the present invention includes a substrate having a silver plating layer formed on a surface thereof, a light emitting diode bonded on the silver plating layer, a reflector disposed on the substrate and surrounding the light emitting diode, and a reflector A silver plating layer formed on the surface is coated with a mica film, which is used for manufacturing an optical semiconductor device including a transparent sealing portion that is filled in and seals a light emitting diode, and a mica film that covers the silver plating layer The mica film has a thickness of 0.005 μm or more and 500 μm or less.

  In this substrate, the silver plating layer is covered with a mica film, and the film thickness of the mica film is in the range of 0.005 μm to 500 μm. Sulfidation of the silver plating layer can be suppressed to a sufficient extent, and a decrease in illuminance of the optical semiconductor device due to blackening of the silver plating layer is suppressed.

  A reflector molded body according to the present invention includes a substrate having a silver plating layer formed on a surface thereof, a light emitting diode bonded on the silver plating layer, and a reflector disposed on the substrate so as to surround the light emitting diode. The silver plating layer formed on the surface is used for the manufacture of an optical semiconductor device comprising a transparent sealing portion that fills the reflector and seals the light emitting diode, and a mica film that covers the silver plating layer. A reflector molded body in which a reflector is disposed on a substrate coated with the above, and the thickness of the mica film is 0.005 μm or more and 500 μm or less.

  In this reflector molded body, the silver plating layer is covered with a mica film, and the film thickness of the mica film is in the range of 0.005 μm to 500 μm. Sulfurization of the silver plating layer can be suppressed to a practically sufficient level, and a decrease in illuminance of the optical semiconductor device due to blackening of the silver plating layer is suppressed.

  An optical semiconductor device manufacturing method according to the present invention includes a substrate having a silver plating layer formed on a surface thereof, a light emitting diode bonded on the silver plating layer, and a substrate on a position surrounding the light emitting diode. A method of manufacturing an optical semiconductor device comprising a reflector, a transparent sealing portion that fills the reflector and seals the light emitting diode, and a mica film that covers the silver plating layer. A light emitting diode is disposed by bonding on a silver plating layer in the reflector after the substrate preparing step for preparing the prepared substrate, the reflector arranging step for arranging the reflector on the substrate after the substrate preparing step, and the reflector arranging step. After the light emitting diode mounting step and the light emitting diode mounting step, the light emitting diode and the silver plating layer are electrically bonded by wire bonding. A light emitting diode connecting step, a light emitting diode sealing step for sealing the light emitting diode by filling a transparent sealing portion in the reflector after the light emitting diode connecting step, and silver plating for covering the silver plating layer with a mica film Including a layer coating step, and the thickness of the mica film is 0.005 μm or more and 500 μm or less.

  In this method of manufacturing an optical semiconductor device, in the silver plating layer coating step, the silver plating layer is coated with a mica film, and the film thickness of the mica film is in the range of 0.005 μm to 500 μm. Sulfidation of the silver plating layer can be suppressed to a sufficient extent, and a decrease in illuminance of the optical semiconductor device due to blackening of the silver plating layer can be significantly suppressed.

  The silver plating layer covering step is performed before the reflector placing step, after the reflector placing step, and before the light emitting diode mounting step, after the light emitting diode connecting step, and the light emitting diode. The aspect performed before a sealing process may be sufficient.

  ADVANTAGE OF THE INVENTION According to this invention, the optical semiconductor device which can suppress the sulfidation of a silver plating layer to a practically sufficient level, its manufacturing method, the base | substrate used for the manufacture, and a reflector molded object are provided.

1 is a cross-sectional view of an optical semiconductor device according to a first embodiment. FIG. 2 is a plan view of the optical semiconductor device shown in FIG. 1. FIG. 2 is a partial enlarged cross-sectional view of the optical semiconductor device shown in FIG. 1. It is a conceptual diagram for demonstrating the structure of the mica film | membrane using fluorinated mica. It is a microscope picture which shows the cross section of the mica film | membrane which used the fluorinated mica. 3 is a flowchart showing a method for manufacturing the optical semiconductor device according to the first embodiment. It is sectional drawing of the reflector molded object which concerns on 1st Embodiment. It is the microscope picture which showed a mode that the wire edge part pierced the viscosity film | membrane. It is sectional drawing of the optical semiconductor device which concerns on 2nd Embodiment. 6 is a flowchart illustrating a method for manufacturing an optical semiconductor device according to a second embodiment. It is sectional drawing of the base | substrate which concerns on 2nd Embodiment. It is sectional drawing of the optical semiconductor device which concerns on 3rd Embodiment. It is a top view of the optical semiconductor device shown in FIG. 6 is a flowchart showing a method for manufacturing an optical semiconductor device according to a third embodiment. It is sectional drawing which showed the mode after the silver plating layer coating process of 3rd Embodiment. It is the schematic of the test device used in the Example. It is the photograph which showed the crack which arose in the mica film | membrane in an Example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In all drawings, the same or corresponding parts are denoted by the same reference numerals.
[First Embodiment]

  1 and 2 show an optical semiconductor device 1A according to the first embodiment. FIG. 1 is a cross-sectional view of the optical semiconductor device 1A, and FIG. 2 is a plan view of the optical semiconductor device 1A.

  As shown in FIGS. 1 and 2, the optical semiconductor device 1 </ b> A is generally classified as a “surface mount type”. This optical semiconductor device 1 </ b> A includes a substrate 10, a blue LED 30 bonded to the surface of the substrate 10, a reflector 20 provided on the surface of the substrate 10 so as to surround the blue LED 30, and the reflector 20 filled with the blue LED 30. And a transparent sealing resin (transparent sealing portion) 40 for sealing. In addition, illustration of the transparent sealing resin 40 is abbreviate | omitted in FIG.

  The substrate 10 is an insulating substrate made of a known insulating material. A silver plating layer 14 is formed on the surface 10 a of the substrate 10 via a copper plating plate 12. The silver plating layer 14 is an electrode that is disposed on the surface of the substrate 10 and is electrically connected to the blue LED 30. The silver plating layer 14 may have any composition as long as it is a plating layer containing silver. For example, the silver plating layer 14 may be formed by plating only silver, or the silver plating layer 14 may be formed by plating nickel and silver in this order.

  Here, the copper plating plate 12 and the silver plating layer 14 are electrically insulated from each other in the insulating portion 16 with the anode E1 side and the cathode E2 side spaced apart. As shown in FIG. 1, the insulating portion 16 is a portion where neither the copper plating plate 12 nor the silver plating layer 14 is formed. Note that a known insulating material may be disposed on the insulating portion 16 as necessary.

  The blue LED 30 is die-bonded to the silver plating layer 14 on the cathode E2 side, and is electrically connected to the silver plating layer 14 via the die-bonding material 32. The blue LED 30 is wire-bonded to the silver plating layer 14 on the anode E1 side, and is electrically connected to the silver plating layer 14 through the bonding wire 34. The anode E1 and the cathode E2 can be exchanged as necessary.

  The reflector 20 is filled with a transparent sealing resin 40 for sealing the blue LED 30 and reflects light emitted from the blue LED 30 to the surface side of the optical semiconductor device 1A.

  The reflector 20 is erected from the surface of the substrate 10 so as to surround the blue LED 30. That is, the reflector 20 has an inner space that rises in the thickness direction of the substrate 10 so as to surround the blue LED 30 and accommodates the blue LED 30 inside, and is formed in a circular shape in plan view (see FIG. 2). A peripheral surface 20a is provided. Although the shape of the inner peripheral surface 20a is not particularly limited, it is preferably formed in a truncated cone shape (funnel shape) whose diameter increases as the distance from the substrate 10 increases, from the viewpoint of improving the illuminance of the optical semiconductor device 1A. In the drawing, as an example of forming the inner peripheral surface 20a, the lower part located on the substrate 10 side is perpendicular to the substrate 10, and the upper part located on the opposite side of the substrate 10 is separated from the substrate 10. An enlarged diameter is shown.

  The reflector 20 is made of a cured product of a thermosetting resin composition containing a white pigment. From the viewpoint of ease of forming the reflector 20, the thermosetting resin composition is preferably one that can be pressure-molded at room temperature (25 ° C.) before thermosetting.

  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.

  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 transparent sealing resin 40 fills the inner space formed by the inner peripheral surface 20 a of the reflector 20 and seals the blue LED 30. The transparent sealing resin 40 is made of a transparent sealing resin having translucency. The transparent sealing resin includes a translucent resin as well as a completely transparent resin. 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 contains an inorganic filler that diffuses light and a phosphor 42 that emits white light using blue light emitted from the blue LED 30 as an excitation source.

  In the optical semiconductor device 1 </ b> A according to the present embodiment, the silver plating layer 14 in the reflector 20 is covered with the mica film 50. That is, as shown in FIG. 3, the reflector 20 has a laminated structure in which the copper plating plate 12, the silver plating layer 14, and the mica film 50 are sequentially laminated from the bottom in the substrate thickness direction.

  The mica film 50 suppresses sulfidation of the silver plating layer 14 by covering the lower silver plating layer 14. As the mica film 50, either natural mica or synthetic mica can be used, and one of natural mica, synthetic mica, and modified products thereof can be used alone or in combination of two or more.

  Examples of natural mica include phlogopite, iron mica, taeniolite, polyisionite, paragonite, tiberite, quinositalite, margarite, sericite, fengite, ceradonite, biotite, lepidite, illite, and muscovite. Examples of commercially available products include wet pulverized mica (manufactured by Yamaguchi Mica, Y series, SA series).

  Examples of the synthetic mica include fluorinated mica, fluorine phlogopite, potassium tetrasilicon mica, sodium tetrasilicon mica, and sodium hectorite. Examples of commercially available products include micro mica, Somasifu (trade name “MEB-3” manufactured by Corp Chemical Co., Ltd.), and swelling mica sol (manufactured by Topy Industries, NTS-10, NTS-5).

  As a modified product of synthetic mica, for example, Somasif (trade name “MAE” manufactured by Co-op Chemical Co., Ltd.) may be mentioned as a commercial product.

  4 and 5 show a mica film 50 composed of fluorinated mica, which is a synthetic mica. As can be seen from these drawings, scaly mica particles (nanofillers) are irregularly tensed. As the layers overlap, a maze-like gas path route is formed in the mica film 50.

  In other words, the mica film 50 covering the silver plating layer 14 extends the path route to the silver plating layer 14, thereby effectively preventing gas such as hydrogen sulfide gas from reaching the silver plating layer 14. Further, sulfidation of the silver plating layer 14 is significantly suppressed. In particular, fluorinated mica has a high aspect ratio such that the thickness H of the mica fragment is 0.5 nm or less, the length L is 10 nm or more and 10,000 nm or less, and the gas path route becomes long. High gas barrier properties can be realized.

  The film thickness d of the mica film 50 has a thickness range of 0.005 μm to 500 μm. Here, when the film thickness d is 0.005 μm or more, sulfidation of the silver plating layer can be suppressed, and blackening of the silver plating layer is suppressed. Even when the film thickness d is 500 μm or less, in the step of forming the mica film (more specifically, the step of drying a mica dilution described later), a situation in which a crack occurs in the mica film is avoided. Sulfurization is suppressed. When cracks occur, the gas reaches the silver plating layer directly from the cracks without passing through the above-mentioned path route. It will decline.

  Therefore, by designing the film thickness d of the mica film 50 to a thickness range of 0.005 μm or more and 500 μm or less, it is possible to achieve a practically sufficiently high gas barrier property for the silver plating layer 14. Moreover, the gas barrier property with respect to the silver plating layer 14 and the transparency of the mica film 50 can be made compatible.

  As described above, in the optical semiconductor device 1A, the silver plating layer 14 is covered with the mica film 50, and the thickness of the mica film 50 is in the range of 0.005 μm to 500 μm. The illuminance reduction of the optical semiconductor device 1A due to the blackening of the silver plating layer 14 is suppressed.

  Next, a method for manufacturing the optical semiconductor device 1A according to the first embodiment will be described.

  FIG. 6 is a flowchart showing a method for manufacturing the optical semiconductor device 1A according to the first embodiment. As shown in FIG. 6, in the manufacturing method of the optical semiconductor device 1A, first, as a substrate preparation step, an insulating substrate 10 having a copper plated plate 12 wired on the surface is prepared (step S101), and a copper plated plate is prepared. The silver plating layer 14 is formed on the surface of 12, and the board | substrate 10 with which the silver plating layer 14 was formed through the copper plating board 12 is formed (step S102).

  Next, as a reflector arranging step, the reflector 20 is formed on the substrate 10 so as to surround the region where the blue LED 30 is to be mounted (step S103). Then, as a silver plating layer coating step, the silver plating layer 14 in the reflector 20 is covered with the mica film 50 (step S104).

  More specifically, the silver plating layer coating step includes a step of applying a mica dilution and a step of drying the mica dilution.

  In the step of applying the mica dilution, the mica dilution is applied to the silver plating layer 14 in the reflector 20 and the silver plating layer 14 is covered with the mica dilution. The mica dilution is a liquid obtained by diluting mica with a solvent. Although it does not restrict | limit especially as an aqueous solvent, For example, liquids, such as water, ethanol, methanol, isopropyl alcohol (henceforth "IPA"), a dioxane, can be employ | adopted individually or in mixture of multiple. it can.

  The application of the mica dilution may be performed, for example, by dropping or spraying the mica dilution from the surface side of the substrate 10 into the inner space of the reflector 20. At this time, the dripping amount or the spraying amount of the mica dilution liquid is adjusted so that at least the entire silver plating layer 14 is covered with the mica dilution liquid.

  In the step of drying the mica diluted solution, the mica diluted solution applied to the silver plating layer 14 is dried to form the mica film 50. At this time, the film thickness d of the mica film 50 is adjusted to a thickness range from 0.005 μm to 500 μm. The thickness of the mica film 50 can be adjusted, for example, by changing the concentration of the mica dilution or increasing or decreasing the amount of the mica dilution applied.

  The film thickness d of the mica film 50 is preferably 0.005 μm or more and 500 μm or less, preferably 0.01 μm or more and 500 μm or less, more preferably 0.05 μm or more and 100 μm or less, and 0.05 μm or more. More preferably, it is 10 μm or less, 0.05 μm or more and 1 μm or less.

  By setting the film thickness d of the mica film 50 to 0.005 μm or more and 500 μm or less, both the gas barrier property with respect to the silver plating layer 14 and the transparency of the mica film 50 can be achieved. In this case, this effect is further improved by setting the film thickness d of the mica film 50 to 0.01 μm to 500 μm, 0.05 μm to 100 μm, 0.05 μm to 10 μm, 0.05 μm to 1 μm. Can do.

  As a result, a reflector molded body 60 as shown in FIG. 7 is formed. In the reflector molded body 60, the reflector 20 is disposed on the substrate 10 on which the silver plating layer 14 is formed, and the mica film 50 is formed on the entire surface of the substrate 10 exposed from the reflector 20. That is, the entire surface area of the silver plating layer 14 and the entire area of the insulating portion 16 in the reflector 20 are covered with the mica film 50.

  Returning to FIG. 6, after the silver plating layer covering step (step S104), as a light emitting diode mounting step, the blue LED 30 is disposed on the silver plating layer 14 in the reflector 20 by bonding (step S105).

  In the light emitting diode mounting step, the blue LED 30 is die-bonded to the silver plating layer 14 on the cathode E2 side in the inner space surrounded by the reflector 20. Accordingly, the blue LED 30 is electrically connected to the silver plating layer 14 on the cathode E2 side through the die bonding material 32, and the blue LED 30 is surrounded by the reflector 20 and accommodated in the inner space.

  Next, as a light emitting diode connection step, the blue LED 30 and the silver plating layer 14 are electrically connected by wire bonding (step S106).

  In the light emitting diode connection step, the blue LED 30 and the silver plating layer 14 on the anode E1 side are wire-bonded. At this time, electrical connection between the blue LED 30 and the silver plating layer 14 is achieved by bonding the end 34 a of the wire 34 to the silver plating layer 14 so as to break through the mica film 50 covering the silver plating layer 14. According to experiments conducted by the inventors, it has been observed that the wire end 34a penetrates the mica film 50 and reaches the silver plating layer 14 as shown in the micrograph shown in FIG. Conductivity with the silver plating layer 14 is confirmed.

  Note that the breakage of the mica film 50 by the wire 34 is performed, for example, by adjusting the layer thickness of the mica film 50, adjusting the load of the bonding head that performs wire bonding, or vibrating the bonding head. .

  Returning to FIG. 6 again, after the light emitting diode connection step (step S106), as the light emitting diode sealing step, the inner space formed by the inner peripheral surface 20a of the reflector 20 is filled with the transparent sealing resin 40, The blue LED 30 is sealed with the transparent sealing resin 40 (step S107).

  The optical semiconductor device 1A shown in FIGS. 1 and 2 is manufactured by the manufacturing method described above.

In the first embodiment described above, the mica diluting solution to be the mica film 50 is dropped into the reflector 20 to form the mica film 50 that covers the entire surface of the silver plating layer 14, and is manufactured. Simplification of the process is achieved. In addition, since the mica film 50 is not interposed between the substrate 10 and the reflector 20, high adhesion between the substrate 10 and the reflector 20 is realized.
[Second Embodiment]

  Next, an optical semiconductor device 1B according to the second embodiment will be described with reference to FIGS. The optical semiconductor device 1B according to the second embodiment is different from the above-described optical semiconductor device 1A according to the first embodiment only in the form of the mica film, and the other configurations are the same.

  That is, as shown in FIG. 9, in the optical semiconductor device 1 </ b> B according to the second embodiment, the mica film 50 is formed not only on the silver plating layer 14 in the reflector 20 but also on the silver plating layer 14 on the substrate 10. It is formed over the entire surface.

  A method for manufacturing the optical semiconductor device 1B according to the second embodiment will be described below. Only parts different from the method of manufacturing the optical semiconductor device 1B according to the second embodiment will be described, and description of the same or similar parts will be omitted.

  FIG. 10 is a flowchart showing a method for manufacturing the optical semiconductor device 1B according to the second embodiment.

  As shown in FIG. 10, in the method of manufacturing the optical semiconductor device 1B, first, the substrate preparation process (steps S201 and S202) is performed in the same manner as the substrate preparation process of the first embodiment.

  Next, as a silver plating layer coating step, the entire surface of the silver plating layer 14 formed on the substrate 10 is covered with the mica film 50 (step S203).

  As a result, a base body 70 as shown in FIG. 11 is formed. In the base body 70, the upper surface of the substrate 10 is entirely covered with the mica film 50. That is, the entire surface region of the silver plating layer 14 and the entire region of the insulating portion 16 are covered with the mica film 50.

  Subsequently, the reflector forming step (step S204), the light emitting diode mounting step (step S205), the light emitting diode connecting step (step S206), and the light emitting diode sealing step (step S207) are performed in this order. The reflector forming process (step S204), the light emitting diode mounting process (step S205), the light emitting diode connecting process (step S206), and the light emitting diode sealing process (step S207) in the second embodiment are the same as those in the first embodiment. This is the same as the reflector forming step (step S103), the light emitting diode mounting step (step S105), the light emitting diode connecting step (step S106), and the light emitting diode sealing step (step S107).

  Also in the optical semiconductor device 1B of the second embodiment described above, the silver plating layer 14 is covered with the mica film 50 and the mica film 50 of the optical semiconductor device 1A of the first embodiment is covered. Since the thickness is in the range of 0.005 μm or more and 500 μm or less, a decrease in illuminance of the optical semiconductor device 1B due to the blackening of the silver plating layer 14 is suppressed.

In the second embodiment described above, since the mica dilution liquid to be the mica film 50 is applied to the entire surface of the substrate 10, it is not necessary to position the reflector relative to the reflector at the time of application, thereby simplifying the manufacturing process. It has been. Further, burrs are generated at the reflector-silver interface portion of the reflector 20 due to the protrusion from the mold during the melting process of the reflector molding resin, but in this embodiment, the burrs can be reduced.
[Third Embodiment]

  Next, an optical semiconductor device 1C according to the third embodiment will be described with reference to FIGS. The optical semiconductor device 1C according to the third embodiment is different from the above-described optical semiconductor device 1A according to the first embodiment only in the form of the substrate and the mica film, and the other configurations are the same.

  That is, as shown in FIG. 12, in the optical semiconductor device 1C according to the third embodiment, a conductive substrate 13 such as a lead frame is used instead of the substrate 10 on which the copper plating plate is wired. In order to insulate the silver plating layer 14 on the anode E1 side and the silver plating layer 14 on the cathode E2 side, an insulating portion 17 penetrating the substrate 13 in the thickness direction is provided. In the first embodiment and the second embodiment, the substrate 10 on which the copper plating plate is wired may be changed to the substrate 13 as appropriate.

  Further, the mica film 50 of the optical semiconductor device 1C according to the third embodiment is formed so as to integrally cover the silver plating layer 14 in the reflector 20 and the blue LED 30 mounted on the silver plating layer 14. ing.

  A method for manufacturing the optical semiconductor device 1C according to the third embodiment will be described below. Only parts different from the method of manufacturing the optical semiconductor device 1C according to the third embodiment will be described, and description of the same or similar parts will be omitted.

  FIG. 14 is a flowchart illustrating a method for manufacturing the optical semiconductor device 1C according to the third embodiment.

  As shown in FIG. 14, in the manufacturing method of the optical semiconductor device 1C, first, as a substrate preparation step, the conductive substrate 13 is prepared (step S301), and the silver plating layer 14 is formed on the surface of the substrate 13, The substrate 13 on which the silver plating layer 14 is formed is formed (step S302).

  Subsequently, the reflector forming step (step S303) and the light emitting diode mounting step (step S304) are performed in this order. The reflector forming process (step S303) and the light emitting diode mounting process (step S304) in the third embodiment are the same as the reflector forming process (step S103) and the light emitting diode mounting process (step S105) in the first embodiment. It is.

  Next, as a silver plating layer coating process, as shown in FIG. 15, the silver plating layer 14 in the reflector 20 and the blue LED 30 mounted on the silver plating layer 14 are integrally covered with a mica film 50 ( Step S305).

  Further, the light emitting diode connecting step (step S306) and the light emitting diode sealing step (step S307) are performed in this order. The light emitting diode connecting step (step S306) and the light emitting diode sealing step (step S307) in the third embodiment are the light emitting diode connecting step (step S106) and the light emitting diode sealing step (step in step S307) in the first embodiment. This is the same as S107).

  In the light emitting diode connection step of the third embodiment, when wire bonding the blue LED 30 and the silver plating layer 14 on the anode E1 side, the mica film 50 covered with the blue LED 30 and the silver plating layer 14 is broken through. Further, both ends 34 a and 34 b of the wire 34 are bonded to the blue LED 30 and the silver plating layer 14. Thereby, conduction between the blue LED 30 and the silver plating layer 14 is achieved.

  Also in the optical semiconductor device 1C of the third embodiment described above, the silver plating layer 14 is covered with the mica film 50, like the optical semiconductor device 1A of the first embodiment and the optical semiconductor device 1B of the second embodiment. In addition, since the thickness of the mica film 50 is in the range of 0.005 μm or more and 500 μm or less, a decrease in illuminance of the optical semiconductor device 1 </ b> C due to the blackening of the silver plating layer 14 is suppressed.

  In the third embodiment described above, the mica film 50 integrally covers all the elements in the reflector 20, so that the mica film 50 effectively suppresses sulfidation of the silver plating layer 14. Further, in the present embodiment, since the mica film can be in contact with the reflector, silver, and the LED surface, it can be integrated with the phosphor 42 and conventionally mixed with the transparent sealing resin. There is an advantage that the amount of the phosphor can be reduced or eliminated, or the phosphor can be localized and the concentration can be increased.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, the blue LED 30 that generates blue light has been described as the light emitting diode that is bonded to the optical semiconductor devices 1A, 1B, and 1C. However, a light emitting diode that generates light other than blue may be used. .

  Hereinafter, in order to clarify the relationship between the thickness of the mica film covering the silver plating layer and the prevention of sulfidation of the silver plating, the examples made by the inventors will be specifically described. It is not limited to examples.

  First, an LED lead frame (OP4 manufactured by Enomoto Co., Ltd.) was prepared as a substrate, and four samples A to D having different mica film thicknesses were produced. Specifically, on a silver plating layer formed on the LED lead frame, a mica dispersion (mica) obtained by diluting a water-swellable synthetic mica dispersion (manufactured by Co-op Chemical Co., Ltd., Somasif MEB-3) with pure water. 3 μl of the diluted solution) was dropped with a micropipette, dried at 70 ° C. for 5 minutes or more in a thermostatic bath or hot plate, and further dried at 150 ° C. for 30 minutes to obtain four samples A (film thicknesses) having different mica film thicknesses. 0.001 μm), Sample B (film thickness 0.005 μm), Sample C (film thickness 500 μm), and Sample D (film thickness 2000 μm) were obtained. The thickness of the mica film was adjusted by changing the concentration of the mica dilution when each sample was prepared.

  The thickness of the mica film of each sample was measured by processing the cross section of the mica film on the silver lead frame with a focused ion beam (FIB) and observing with a scanning ion microscope (SIM).

  Each sample A to D was exposed to a sulfide gas atmosphere by a tester 80 shown in FIG. Specifically, the sample 81 is placed on a stainless steel wire mesh 83 in a sealable glass bottle 82 so as to face upward, and an aluminum cup 85 in which sulfur powder 84 (about 0.5 g) is placed below the sample 81. And exposed to a sulfurizing gas atmosphere at 80 ° C. for 4 hours.

  And the presence or absence of sulfidation (namely, blackening) of a silver plating layer was confirmed visually.

The results were as shown in Table 1 below.

  That is, in Samples B and C, no sulfidation of the silver plating layer was confirmed, whereas in Samples A and D, the silver plating layer was sulfided and blackened. Further, in sample D, as shown in FIG. 17, a large crack (a portion that looks black in the figure) was confirmed in the mica film.

  In the sample A having a mica film thickness of 0.001 μm, the mica film is too thin, so that the effect of extending the gas path route cannot be sufficiently obtained, and the silver plating layer is considered to be sulfided.

  Further, in sample D having a mica film thickness of 2000 μm, although the mica film was sufficiently thick, it was considered to be cracked because it was too thick, gas entered from the cracked part, and the silver plating layer was sulphurized. .

  On the other hand, in the samples B and C in which the thickness of the mica film was in the range of 0.005 μm or more and 500 μm or less, the film thickness was in an appropriate range, so that the sulfidation of the silver plating layer was effectively suppressed. it is conceivable that.

  That is, from the above results, it is clear that the sulfidation of the silver plating layer can be practically sufficiently suppressed by setting the thickness of the mica film covering the silver plating layer in the range of 0.005 μm to 500 μm.

DESCRIPTION OF SYMBOLS 1A, 1B, 1C ... Optical semiconductor device 10, 13 ... Board | substrate, 12 ... Copper plating board, 14 ... Silver plating layer, 20 ... Reflector, 30 ... Blue LED (blue light emitting diode), 32 ... Die-bonding material, 34 ... Bonding Wire: 40 ... Transparent sealing resin, 42 ... Phosphor, 50 ... Mica film, 60 ... Reflector molding, 70 ... Substrate.

Claims (7)

A substrate having a silver plating layer formed on the surface;
A light emitting diode bonded on the silver plating layer;
A reflector disposed on the substrate and surrounding the light emitting diode;
A transparent sealing portion that fills the reflector and seals the light emitting diode;
A mica film covering the silver plating layer,
An optical semiconductor device, wherein the mica film has a thickness of 0.005 μm to 500 μm. A substrate having a silver plating layer formed on the surface;
A light emitting diode bonded on the silver plating layer;
A reflector disposed on the substrate and surrounding the light emitting diode;
A transparent sealing portion that fills the reflector and seals the light emitting diode;
Used for the manufacture of an optical semiconductor device comprising a mica film covering the silver plating layer,
The silver plating layer formed on the surface is a substrate coated with the mica film,
The base | substrate whose thickness of the said mica film is 0.005 micrometer or more and 500 micrometers or less. A substrate having a silver plating layer formed on the surface;
A light emitting diode bonded on the silver plating layer;
A reflector disposed on the substrate and surrounding the light emitting diode;
A transparent sealing portion that fills the reflector and seals the light emitting diode;
Used for manufacturing an optical semiconductor device comprising a mica film covering the silver plating layer,
A reflector molded body in which the reflector is disposed on a substrate on which the silver plating layer formed on the surface is coated with the mica film,
A reflector molded body, wherein the mica film has a thickness of 0.005 μm or more and 500 μm or less. A substrate having a silver plating layer formed on the surface;
A light emitting diode bonded on the silver plating layer;
A reflector disposed on the substrate and surrounding the light emitting diode;
A transparent sealing portion that fills the reflector and seals the light emitting diode;
A method of manufacturing an optical semiconductor device comprising a mica film covering the silver plating layer,
A substrate preparation step of preparing a substrate having a silver plating layer formed on the surface;
A reflector placement step of placing the reflector on the substrate after the substrate preparation step;
After the reflector placement step, a light emitting diode mounting step for placing the light emitting diode on the silver plating layer in the reflector by bonding;
After the light emitting diode mounting step, a light emitting diode connection step of electrically connecting the light emitting diode and the silver plating layer by wire bonding;
After the light emitting diode connection step, a light emitting diode sealing step of sealing the light emitting diode by filling the reflector with a transparent sealing portion;
A silver plating layer coating step of coating the silver plating layer with a mica film,
The manufacturing method of the optical semiconductor device whose thickness of the said mica film is 0.005 micrometer or more and 500 micrometers or less.   The method for manufacturing an optical semiconductor device according to claim 4, wherein the silver plating layer covering step is performed before the reflector arranging step.   The method for manufacturing an optical semiconductor device according to claim 4, wherein the silver plating layer covering step is performed after the reflector arranging step and before the light emitting diode mounting step. The method for manufacturing an optical semiconductor device according to claim 4, wherein the silver plating layer covering step is performed after the light emitting diode connecting step and before the light emitting diode sealing step.