JP2015076568A - Method for manufacturing wavelength conversion member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a wavelength conversion member having an opening and a notched portion while suppressing the occurrence of fracture or crack.SOLUTION: A method for manufacturing a wavelength conversion member having an opening and/or a notched portion formed therein comprises the steps of: preparing a green sheet including glass powder and inorganic phosphor powder; processing the green sheet to form the opening and/or the notched portion; and baking the green sheet after the processing.

Description

  The present invention manufactures a wavelength conversion member for converting a part of light emitted from a semiconductor light emitting element such as an LED (light emitting diode) or an LD (laser diode) into another wavelength and mainly irradiating white light. Regarding the method.

  In recent years, semiconductor light-emitting element devices such as white LEDs have attracted attention as next-generation light sources that replace incandescent bulbs and fluorescent lamps. In general, a white LED has a structure in which a mixture of an inorganic phosphor powder and a resin is coated and molded on an excitation LED chip. However, since the heat and light emitted from the LED chip are intensively applied to a limited portion, the resin used for the coating mold is easily colored or deformed. Therefore, there is a problem that the emission color changes in a short period of time and the lifetime as a semiconductor light emitting device is short. This problem is considered to be serious with the increase in output of the LED chip, and the development of a semiconductor light emitting element device having excellent heat resistance has been desired.

  On the other hand, the LED device using the wavelength conversion member which consists of inorganic solid which does not use a resin matrix is proposed (for example, refer patent document 1). The wavelength conversion member has excellent heat resistance and hardly undergoes thermal degradation. The wavelength conversion member disclosed in Patent Document 1 is provided, for example, as a plate-shaped molded body by filling a mold with a mixture of glass powder and inorganic phosphor powder and heat-treating (sintering) in the vicinity of the softening point. The

  FIG. 5 shows a conventional semiconductor light emitting element device using a plate-like wavelength conversion member. As shown in FIG. 5, in the semiconductor light emitting device 1, the semiconductor light emitting device 2 is electrically connected to a lead electrode (not shown) on the substrate 4 using a bonding wire 3. Here, when the wavelength conversion member 5 is mounted on the semiconductor light emitting element 2, the bonding wire 3 obstructs the approach between the wavelength conversion member 5 and the semiconductor light emitting element 2, thereby reducing the degree of mounting freedom. In addition, since the distance D between the semiconductor light emitting element 2 and the wavelength conversion member 5 is increased, there is a problem that the efficiency of incidence of light emitted from the semiconductor light emitting element 2 on the wavelength conversion member 5 is lowered.

  Further, since the bonding wire 3 is present between the semiconductor light emitting element 2 and the wavelength conversion member 5, the bonding wire 3 absorbs light emitted from the semiconductor light emitting element 2, and the shadow of the bonding wire 3 is changed to the wavelength conversion member. There is also a problem that the luminous flux value is lowered due to the projection onto the image.

  In order to solve the above problem, there has been proposed a wavelength conversion member in which an opening or a notch for forming a bonding wire is formed (see, for example, Patent Document 2). If the bonding wire is disposed so as to penetrate through the opening or notch formed in the wavelength conversion member, the distance D between the light emitting element and the wavelength conversion member can be reduced, and the decrease in the luminous flux value can be suppressed. Can do.

JP 2003-258308 A JP 2010-141273 A

  In Patent Document 2, machining or laser processing is cited as a method of forming an opening or notch in the wavelength conversion member. However, when a wavelength conversion member made of an inorganic solid is machined, there is a problem that cracks and cracks are likely to occur. In particular, when the wavelength conversion member is thin, the problem is likely to appear remarkably. On the other hand, although laser processing is relatively difficult to generate cracks and cracks, there is a problem that processing takes time and is inefficient.

  In view of the above, an object of the present invention is to provide a method for efficiently producing a wavelength conversion member having an opening or a notch while suppressing the occurrence of cracks and cracks.

  The method for producing a wavelength conversion member of the present invention is a method for producing a wavelength conversion member having an opening and / or a notch, and a green sheet containing glass powder and inorganic phosphor powder is prepared. And a step of processing the green sheet to form an opening and / or a notch, and a step of firing the processed green sheet.

  In the method for producing a wavelength conversion member of the present invention, the green sheet is preferably processed by mechanical punching or laser punching.

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing efficiently the wavelength conversion member which has an opening part and a notch part, suppressing generation | occurrence | production of a crack and a crack can be provided.

(A) It is a top view which shows 1st embodiment of the wavelength conversion member produced by the manufacturing method of this invention. (B) It is a top view which shows 2nd embodiment of the wavelength conversion member produced by the manufacturing method of this invention. (C) It is a top view which shows 3rd embodiment of the wavelength conversion member produced by the manufacturing method of this invention. (D) It is a top view which shows 4th embodiment of the wavelength conversion member produced by the manufacturing method of this invention. It is sectional drawing which shows one Embodiment of the semiconductor light-emitting device using the wavelength conversion member of FIG. (A) It is a top view which shows 5th embodiment of the wavelength conversion member produced by the manufacturing method of this invention. (B) It is a top view which shows 6th embodiment of the wavelength conversion member produced by the manufacturing method of this invention. (C) It is a top view which shows 7th embodiment of the wavelength conversion member produced by the manufacturing method of this invention. It is sectional drawing which shows one Embodiment of the semiconductor light-emitting element device using the wavelength conversion member of FIG. It is sectional drawing which shows the conventional semiconductor light-emitting device.

  The manufacturing method of the wavelength conversion member of this invention is related with the method for manufacturing the wavelength conversion member in which the opening part and / or the notch part were formed.

  1st-4th embodiment of the wavelength conversion member in which the opening part and / or the notch part were formed is shown to Fig.1 (a)-(d). As shown in FIG. 1, the wavelength conversion member 5 is provided with an opening O or a notch C.

  FIG. 2 is a sectional view showing an embodiment of a semiconductor light emitting device using the wavelength conversion member of FIG. As shown in FIG. 2, the semiconductor light emitting element 2 is installed on the substrate 4 and is electrically connected to a lead electrode (not shown) on the substrate 4 by two arch-shaped bonding wires 3. . Further, a plate-like wavelength conversion member 5 is installed above the semiconductor light emitting element 2. Although not shown in FIG. 2, the wavelength conversion member 5 is usually used by being installed on a casing or a cup. Here, the bonding wire 3 connected to the semiconductor light emitting element 2 once passes through the opening O or the notch C, then bends in an arch shape on the wavelength conversion member 5, and again opens the opening O or the notch C. Is connected to the lead electrode on the substrate 4.

  FIGS. 3A to 3D show fifth to seventh embodiments of the wavelength conversion member in which the opening and / or the notch are formed. As shown in FIG. 3, the wavelength conversion member 1 is provided with an opening O or a notch C.

  FIG. 4 is a cross-sectional view showing one embodiment of a semiconductor light emitting device using the wavelength conversion member of FIG. In the present embodiment, the two bonding wires 3 pass through one opening O or notch C, protrude above the wavelength conversion member 5, bend in an arch shape, and then the wavelength conversion member 5. The lead electrode is connected to the lead electrode through the outside, that is, without penetrating the opening O and the notch C again.

  In addition, the shape of the opening part formed in a wavelength conversion member is not specifically limited, Polygons, such as a rectangle and a triangle, may be sufficient besides circular and an ellipse. Further, the shape of the cutout portion is not particularly limited, and is appropriately selected from a part of a circle (such as a semicircle), a part of an ellipse (such as a half ellipse), a polygon such as a triangle and a rectangle.

  As described above, it is preferable that the size of the opening and notch formed in the wavelength conversion member is as small as possible from the viewpoint of light conversion efficiency. For example, when the opening (or notch) is circular (or part of a circle), the diameter is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less. Although a minimum is not specifically limited, Actually, it is 10 micrometers or more, Furthermore, it is 30 micrometers or more. When the opening (or notch) is elliptical (or part of an elliptical shape), the minor axis is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less. Although a minimum is not specifically limited, Actually, it is 10 micrometers or more, Furthermore, it is 30 micrometers or more. When the opening (or notch) is rectangular, the short side is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less. Although a minimum is not specifically limited, Actually, it is 10 micrometers or more, Furthermore, it is 30 micrometers or more.

  In addition, both the opening part and the notch part may be formed in the wavelength conversion member.

  Although the thickness of a wavelength conversion member is not specifically limited, 0.05-1 mm is preferable, 0.08-0.5 mm is more preferable, 0.1-0.2 mm is further more preferable. When the thickness of the wavelength conversion member is too small, the mechanical strength is inferior, and manufacturing and processing become difficult. On the other hand, when the thickness of the wavelength conversion member is too large, the light emitted from the semiconductor light emitting element is difficult to transmit and the light flux value tends to decrease.

The size of the wavelength conversion member is not particularly limited, and is appropriately selected according to specifications required for the semiconductor light emitting device. Specifically, the size of the wavelength conversion member ^{(area), 0.1~10000mm 2, 0.5~1000mm 2,} in particular selected in the range of 1 to 100 mm ^2. For example, when the planar shape is rectangular, it is selected in the range of 0.5 × 0.5 mm to 50 × 50 mm, 0.6 × 0.6 mm to 10 × 10 mm, particularly 0.8 × 0.8 mm to 5 × 5 mm. The When the planar shape is circular, the diameter is selected in the range of 0.5 to 50 mm, 0.6 to 10 mm, particularly 0.8 to 5 mm.

  The method for producing a wavelength conversion member of the present invention includes a step of preparing a green sheet containing glass powder and inorganic phosphor powder, a step of processing the green sheet to form an opening and / or a notch, and A step of firing the green sheet after processing. Hereinafter, the manufacturing method of the wavelength conversion member of this invention is demonstrated in detail for every process.

(Green sheet preparation process)
The glass powder used in the present invention has a role as a medium for stably holding the inorganic phosphor powder. Since the reactivity with the inorganic phosphor powder varies depending on the glass composition system to be used, it is necessary to select the glass composition to be used in consideration of various conditions.

  The glass powder is not particularly limited as long as it does not easily react with the inorganic phosphor powder, but a glass powder having a softening point of 850 ° C. or lower, preferably 800 ° C. or lower is preferably used. When the softening point of the glass powder is increased, the firing temperature is also increased, so that the inorganic phosphor powder is deteriorated and it becomes difficult to obtain a wavelength conversion member having high luminous efficiency.

Examples of the glass powder include SiO ₂ —B ₂ O ₃ glass, SiO ₂ —RO glass (R is at least one selected from Mg, Ca, Sr and Ba), SiO ₂ —B ₂ O _3. -RO based _{glass, SiO 2 -B 2 O 3 -R} '2 O -based glass (R' is at least one selected Li, from Na and _{K), SiO 2 -B 2 O} 3 -Al 2 O 3 Glass, SiO ₂ —B ₂ O ₃ —ZnO glass, ZnO—B ₂ O ₃ glass, or the like can be used. Incidentally, for the purpose of low-temperature firing is relatively low softening point (e.g., 400 ° C. or less, more 380 ° C. or less) is obtained easily _ZnO-B 2 _{O 3} based glass or _SnO-P 2 _{O 5} based glass Is preferably selected. When it is desired to improve the weather resistance of the wavelength conversion member, SiO ₂ —B ₂ O ₃ glass, SiO ₂ —RO glass, SiO ₂ —B ₂ O ₃ —RO glass, SiO ₂ —B ₂ O ₃ — R ′ ₂ O glass, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ glass, or SiO ₂ —B ₂ O ₃ —ZnO glass may be selected.

SiO ₂ -B ₂ O ₃ -RO based glass, in _{mass%, SiO 2 30~70%, B} 2 O 3 1~15%, 0~10% MgO, CaO 0~25%, SrO 0~10% BaO 8 to 40%, RO 10 to 45%, Al ₂ O ₃ 0 to 20%, and ZnO 0 to 10% are preferably contained. In addition to the above components, various components can be contained within a range that does not impair the gist of the present invention. For example, R ′ ₂ O, P ₂ O ₅ , La ₂ O ₃ or the like may be added in a total amount of 30% or less.

The composition range of the SnO—P ₂ O ₅ glass is mass%, and preferably contains SnO 30 to 90% and P ₂ O ₅ 10 to 60%. Further, the _B 2 _{O 3} in addition to the above-mentioned components may contain 0-30%. In addition, various components can be contained within a range not impairing the gist of the present invention. For example, SiO ₂ , Al ₂ O ₃ , RO, R ′ ₂ O, etc. may be contained up to 30% in total.

The average of the glass powder the particle diameter _{D 50} is preferably 0.1~300μm, 0.7~250μm is more preferable. When the average particle diameter D ₅₀ is too small, foaming during firing, the porosity of the wavelength conversion member (ratio of residual bubbles) is increased, or the luminous efficiency is lowered, the mechanical strength of the wavelength conversion member is reduced risk There is. On the other hand, when the average particle diameter D ₅₀ of the glass powder is too large, there is a tendency for low-temperature firing becomes difficult. Further, it tends to be difficult to form the opening and / or the cutout with high accuracy. From the viewpoint of performing high precision machining, the average particle diameter D ₅₀ of the glass powder in the case of the opening and / or cutout size (in the case of circular diameter, oval (or a portion of an ellipse) It is preferably about 1/10 or less of the short diameter and the short side in the case of a rectangle. In the present invention, the average particle diameter D ₅₀ refers to a value measured by a laser diffraction method.

  Any inorganic phosphor powder can be used as long as it is generally available in the market. Inorganic phosphor powders comprising oxides (including garnets such as YAG), nitrides, oxynitrides, sulfides, rare earth oxysulfides, halides, aluminate chlorides, halophosphates, etc. Is mentioned. The oxide phosphor powder has a feature that it is stable even when mixed with glass powder and heated at a high temperature. Each phosphor powder of nitride, oxynitride, sulfide, rare earth oxysulfide, halide, aluminate chloride, and halophosphate chloride reacts with glass powder during firing, and abnormal reactions such as foaming and discoloration It is easy to cause. The degree tends to become more prominent as the firing temperature is higher. When using these inorganic phosphor powders, the reaction with the glass powder can be suppressed by optimizing the firing temperature and the glass powder composition.

  A plurality of inorganic phosphor powders may be mixed and used in accordance with the wavelength range of the excitation light and the color to be emitted. For example, in order to obtain white light by irradiating ultraviolet excitation light, inorganic phosphor powders emitting blue, green, and red fluorescence may be mixed and used.

The average particle diameter _{D 50} of the inorganic phosphor powder is preferably 1~75μm, 1~50μm is more preferable. When the average particle diameter D ₅₀ is too small, or react with the glass powder during firing, or by foaming, there is a tendency that the porosity in the wavelength converting member increases. On the other hand, when the average particle diameter D ₅₀ of the inorganic phosphor powder is too large, the excitation light is hardly transmitted to the inner wavelength conversion member, the light emission efficiency tends to decrease.

  The luminous efficiency of the wavelength conversion member varies depending on the type and content of the inorganic phosphor powder, the thickness of the wavelength conversion member, and the like. If you want to increase the light emission efficiency of the wavelength conversion member, increase the transmittance of excitation light or wavelength converted light by increasing the thickness, or increase the content of inorganic phosphor powder to increase the light emission amount You can adjust with. However, when there is too much content of inorganic fluorescent substance powder, it will become difficult to sinter and there exists a tendency for the porosity of a wavelength conversion member to become large. On the other hand, if the content of the inorganic phosphor powder is too small, the emission intensity tends to decrease. Therefore, the content of the inorganic phosphor powder in the wavelength conversion member is preferably adjusted in the range of 0.01 to 30% by mass, 0.05 to 20% by mass, and particularly 0.08 to 15% by mass.

  Glass powder and inorganic phosphor powder are mixed to prepare a mixed powder. As the mixed powder, you may use what consists only of glass powder and inorganic phosphor powder, but besides that, inorganic powder such as crystal powder such as high softening point glass powder, silica powder, or alumina powder, You may make it contain for the purpose of the intensity | strength improvement of a wavelength conversion member, adjustment of hue, orientation, scattering property, etc. In the wavelength conversion member, the total content of the inorganic powder is preferably 0.01 to 50% by mass, and more preferably 0.05 to 20% by mass.

  A resin binder containing a predetermined amount of resin, plasticizer, solvent and the like is added to the mixed powder to form a slurry. The slurry is formed into a sheet on a film of polyethylene terephthalate (PET) or the like by a doctor blade method or the like. A green sheet is obtained by drying the slurry formed into a sheet.

(Green sheet processing process)
The green sheet obtained above is processed to form openings and / or notches. Examples of the processing method include mechanical punching using a metal pin and laser punching using a carbon dioxide laser. As described above, when machining is performed on a wavelength conversion member made of an inorganic solid, there is a problem that cracks and cracks are likely to occur. On the other hand, laser processing of a wavelength conversion member made of an inorganic solid has a problem that although cracks and cracks are relatively unlikely to occur, the processing takes time and is inefficient (and consequently increases costs). In this invention, since it processes with respect to a green sheet, an opening part and / or a notch part can be provided in a short time, suppressing generation | occurrence | production of a crack and a crack. In particular, mechanical punching and laser punching enable high-speed and high-positioning processing. For example, when the green sheet is laser punched with a carbon dioxide laser, the resin binder can be burned out instantaneously, so that the opening and / or the cutout can be formed with high dimensional accuracy and in a short time. Can do.

  Note that only one green sheet may be used, or processing may be performed in a state where two or more green sheets are laminated or laminated and pressure-bonded. Thereby, it becomes possible to improve the production efficiency and to easily produce a wavelength conversion member having a desired thickness. Further, the opening and / or notch may be formed after the green sheet is cut into a desired shape, or the opening and / or notch is formed in the green sheet and then the desired shape is obtained. It may be cut.

(Green sheet firing process)
A wavelength conversion member is obtained by baking the green sheet processed above. Specifically, the green sheet is first degreased by heat treatment at about 200 to 550 ° C., and then sintered by heat treatment at about 750 to 1000 ° C. Thereby, a wavelength conversion member is obtained.

  In addition, since a green sheet tends to shrink at the time of heat processing, it is preferable to heat-process in the state pinched | interposed between restraining members, such as an alumina base material. Further, the obtained wavelength conversion member may be cut and polished so as to have a desired shape.

  The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

(Example)
SiO ₂ —B ₂ O ₃ —RO glass powder having a composition of 60% by mass, SiO ₂ 60%, B ₂ O ₃ 10%, BaO 10%, and CaO 20% (softening point 820 ° C., average particle size) D ₅₀ : 2.5 μm) To 90% by mass, 10% by mass of YAG phosphor powder was added to obtain a mixed powder, and an acrylic binder, a plasticizer and a solvent were appropriately mixed to prepare a slurry. The obtained slurry was formed into a sheet on a PET film by a doctor blade method to obtain a green sheet.

  A circular punching hole having a diameter of 80 μm was formed at a plurality of locations on the obtained green sheet using a mechanical punching machine (MP-7150Z manufactured by UHT). The time required for processing was less than 1 second. The green sheet after processing was fired at 830 ° C. to obtain a wavelength conversion member (thickness 0.2 mm) as shown in FIG.

(Comparative Example 1)
A wavelength conversion member was obtained in the same manner as in the example except that the green sheet was not processed. When trying to form a through-hole using the mechanical punching machine in the obtained wavelength conversion member, the crack and the crack generate | occur | produced.

(Comparative Example 2)
A wavelength conversion member was obtained in the same manner as in the example except that the green sheet was not processed. By using a femtosecond laser irradiation device (manufactured by Cyber Laser Co., Ltd.) on the obtained wavelength conversion member, a circular through hole having a diameter of 80 μm is formed, whereby a wavelength conversion member (thickness 0. 0 mm) as shown in FIG. 2 mm). The time required for processing was 5 minutes.

DESCRIPTION OF SYMBOLS 1 Semiconductor light-emitting device 2 Semiconductor light-emitting device 3 Bonding wire 4 Substrate 5 Wavelength conversion member O Opening part C Notch

Claims (2)

A method for producing a wavelength conversion member in which an opening and / or a notch is formed,
Preparing a green sheet containing glass powder and inorganic phosphor powder,
Processing the green sheet to form openings and / or notches, and
A step of firing the green sheet after processing;
A method for producing a wavelength conversion member, comprising:   The method for manufacturing a wavelength conversion member according to claim 1, wherein the green sheet is processed by mechanical punching or laser punching.