TW201830733A

TW201830733A - Light emitting device

Info

Publication number: TW201830733A
Application number: TW106135049A
Authority: TW
Inventors: 清水寛之; 浅野秀樹; 村田隆
Original assignee: 日商日本電氣硝子股份有限公司
Priority date: 2016-10-19
Filing date: 2017-10-13
Publication date: 2018-08-16
Also published as: WO2018074170A1; JP2018067618A

Abstract

Provided is a light emitting device which is capable of improving the extraction efficiency for excitation light, thereby being capable of enhancing the luminous efficiency. This light emitting device is characterized by comprising a wavelength conversion member 3 which is obtained by dispersing phosphor particles 8 in a glass matrix 7, a light source 2 which irradiates the wavelength conversion member 3 with excitation light, and an adhesive layer 4 which is arranged between the wavelength conversion member 3 and the light source 2. This light emitting device is also characterized in that the difference between the refractive index of the glass matrix 7 and the refractive index of the adhesive layer 4 is 0.1 or less.

Description

發光裝置Illuminating device

本發明係關於一種使用LED(Light Emitting Diode，發光二極體)或LD(Laser Diode，雷射二極體)等激發光源之發光裝置。The present invention relates to a light-emitting device using an excitation light source such as an LED (Light Emitting Diode) or an LD (Laser Diode).

近年來，作為代替螢光燈或白熾燈之下一代光源，使用LED或LD等激發光源之發光裝置備受注目。作為此種下一代光源之一例，業界熟知有將出射藍光之LED與吸收來自LED之光之一部分並轉換為黃光之波長轉換構件組合而成之發光裝置。該發光裝置發出自LED出射之藍光與自波長轉換構件出射之黃光之合成光即白光。作為波長轉換構件，先前一直使用於樹脂基質中分散有無機螢光體粉末者。然而，於使用該波長轉換構件之情形時，存在因來自LED之光導致樹脂劣化，而使發光裝置之亮度容易降低之問題。尤其存在因LED所發出之熱或高能量之短波長(藍色～紫外)光而使塑模樹脂劣化，產生變色或變形之問題。因此，提出有包含代替樹脂而於玻璃基質中分散固定有螢光體之完全無機固體之波長轉換構件(例如參照專利文獻2及3)。該波長轉換構件具有如下特徵：成為母材之玻璃不易因LED之熱或照射光而發生劣化，難以產生變色或變形等問題。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利特開2000-208815號公報 [專利文獻2]日本專利特開2003-258308號公報 [專利文獻3]日本專利特開2007-016171號公報In recent years, as a next-generation light source that replaces a fluorescent lamp or an incandescent lamp, a light-emitting device using an excitation light source such as an LED or an LD has been attracting attention. As an example of such a next-generation light source, a light-emitting device in which an LED that emits blue light and a wavelength conversion member that absorbs a part of light from the LED and converts it into yellow light are known in the art. The illuminating device emits white light which is a combination of the blue light emitted from the LED and the yellow light emitted from the wavelength converting member. As the wavelength converting member, those conventionally used for dispersing inorganic phosphor powder in a resin matrix have been used. However, in the case of using the wavelength conversion member, there is a problem that the deterioration of the resin due to light from the LED causes the luminance of the light-emitting device to be easily lowered. In particular, there is a problem that the mold resin is deteriorated due to heat generated by the LED or short-wavelength (blue to ultraviolet) light of high energy, causing discoloration or deformation. Therefore, a wavelength conversion member including a completely inorganic solid in which a phosphor is dispersed and fixed in a glass matrix instead of a resin has been proposed (see, for example, Patent Documents 2 and 3). This wavelength conversion member is characterized in that the glass to be a base material is less likely to be deteriorated by heat of the LED or the irradiation light, and it is difficult to cause discoloration or deformation. [Prior Art Document] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-208815 (Patent Document 2) Japanese Patent Laid-Open Publication No. JP-A No. 2003-258308 (Patent Document 3) Japanese Patent Laid-Open No. 2007-016171 Bulletin

[發明所欲解決之問題] 於使用覆晶型LED等作為光源之情形時，存在於光源與波長轉換構件之間配置接著劑層而固定之情形。來自光源之激發光通過接著劑層而入射至波長轉換構件。激發光被波長轉換構件所含之螢光體轉換成螢光，並自波長轉換構件之與光源為相反側之面與未經波長轉換之激發光一起出射。此處，若波長轉換構件與光出射側之空氣層之折射率差較大，則於兩者之界面處產生光反射，光提取效率容易降低。因此，為了減小波長轉換構件與空氣層之折射率差，考慮使波長轉換構件之折射率降低。然而，存在即便僅使波長轉換構件之折射率降低亦未必會提高光提取效率之情形。該事實提示出光提取效率亦同波長轉換構件與空氣層之折射率差以外之要因有關。然而，先前為了使發光裝置之光提取效率最佳化，而未對構成發光裝置之各構件之折射率之關係進行充分研究。本發明之目的在於提供一種可使激發光之提取效率提昇而提高發光效率之發光裝置。 [解決問題之技術手段] 本發明之發光裝置之特徵在於具備：於玻璃基質中分散有螢光體粒子之波長轉換構件、對波長轉換構件照射激發光之光源、及設置於波長轉換構件與光源之間之接著劑層，且玻璃基質與接著劑層之折射率之差為0.1以下。玻璃基質之折射率較佳為1.6以下。接著劑層較佳為由矽酮樹脂構成。玻璃基質之折射率較佳為1.48以上。較佳為於波長轉換構件、光源、及接著劑層之周圍具備反射層。於該情形時，反射層較佳為由樹脂組合物或玻璃陶瓷構成。 [發明之效果] 根據本發明，可使激發光之提取效率提昇而提高發光效率。[Problems to be Solved by the Invention] When a flip-chip type LED or the like is used as a light source, there is a case where an adhesive layer is disposed between the light source and the wavelength conversion member and fixed. The excitation light from the light source is incident on the wavelength conversion member through the adhesive layer. The excitation light is converted into fluorescence by the phosphor contained in the wavelength conversion member, and is emitted from the surface opposite to the light source of the wavelength conversion member together with the excitation light without wavelength conversion. Here, when the refractive index difference between the wavelength conversion member and the air layer on the light exit side is large, light reflection occurs at the interface between the two, and the light extraction efficiency is liable to lower. Therefore, in order to reduce the difference in refractive index between the wavelength converting member and the air layer, it is considered to lower the refractive index of the wavelength converting member. However, there is a case where the light extraction efficiency is not necessarily improved even if only the refractive index of the wavelength converting member is lowered. This fact suggests that the light extraction efficiency is also related to the cause of the difference in refractive index between the wavelength converting member and the air layer. However, in order to optimize the light extraction efficiency of the light-emitting device, the relationship between the refractive indices of the members constituting the light-emitting device has not been sufficiently studied. It is an object of the present invention to provide a light-emitting device which can improve the extraction efficiency of excitation light and improve the light-emitting efficiency. [Means for Solving the Problems] The light-emitting device of the present invention includes a wavelength conversion member in which phosphor particles are dispersed in a glass matrix, a light source that emits excitation light to the wavelength conversion member, and a wavelength conversion member and a light source. The adhesive layer is interposed and the difference in refractive index between the glass substrate and the adhesive layer is 0.1 or less. The refractive index of the glass substrate is preferably 1.6 or less. The subsequent layer is preferably composed of an anthrone resin. The refractive index of the glass substrate is preferably 1.48 or more. Preferably, a reflection layer is provided around the wavelength conversion member, the light source, and the adhesive layer. In this case, the reflective layer is preferably composed of a resin composition or a glass ceramic. [Effect of the Invention] According to the present invention, the extraction efficiency of the excitation light can be improved to improve the luminous efficiency.

以下，對較佳之實施形態進行說明。但是，以下之實施形態僅為例示，本發明並不限定於以下之實施形態。又，各圖式中，有時對實質上具有同一功能之構件以相同符號進行參照。圖1係表示本發明之一實施形態之發光裝置的模式性剖視圖。圖2係表示本發明之一實施形態之發光裝置的模式性俯視圖。如圖1所示，本實施形態之發光裝置1具備波長轉換構件3、對波長轉換構件3照射激發光之光源2、及設置於波長轉換構件3與光源2之間之接著劑層4。如圖1及圖2所示，於本實施形態中，光源2設置於基板5上。又，於波長轉換構件3、光源2、及接著劑層4之周圍配置有反射層6。藉由配置反射層6，可反射激發光及螢光而抑制光漏至外部，可提高光之提取效率。圖3係將本發明之一實施形態之發光裝置中之波長轉換構件放大表示的模式性剖視圖。如圖3所示，波長轉換構件3係藉由於玻璃基質7中分散螢光體粒子8而構成。作為光源2，可使用LED或LD等。於使用LED晶片作為光源2之情形時，可覆晶安裝LED晶片。作為覆晶型LED，例如可列舉於發光層上設置有藍寶石層者。藍寶石層設置於激發光之出射側。於光源2上設置有接著劑層4。於接著劑層4上設置有波長轉換構件3。自光源2出射之激發光通過接著劑層4入射至波長轉換構件3。藉由入射至波長轉換構件3之激發光，螢光體粒子8被激發，而自螢光體粒子8出射螢光。自螢光體粒子8出射之螢光與通過波長轉換構件3後之激發光之合成光自波長轉換構件3出射。再者，如上所述，為了提高發光裝置之光提取效率，存在即便僅使波長轉換構件之折射率降低亦未必會提高光提取效率之情形。其亦示於下述試驗資料中。根據本發明者等之調查結果，發現構成波長轉換構件之玻璃基質與接著劑層之折射率差對光提取效率產生影響。具體而言，於本實施形態中，將波長轉換構件3之玻璃基質7與接著劑層4之折射率之差設定為0.1以下。藉此，可抑制激發光於波長轉換構件3與接著劑層4之界面處發生反射，可使激發光之提取效率提昇而提高發光效率。作為構成接著劑層4之接著劑，例如可列舉矽酮樹脂系、環氧樹脂系、乙烯系樹脂系、丙烯酸系樹脂系等。玻璃基質7與接著劑層4之折射率(nd)之差較佳為0.08以下，進而較佳為0.07以下，尤佳為0.04以下。接著劑層4之折射率較佳為1.38～1.60之範圍，更佳為1.40～1.58之範圍。玻璃基質7之折射率較佳為1.48～1.60之範圍，更佳為1.50～1.58之範圍。玻璃基質7可用作無機螢光體等螢光體粒子8之分散介質，只要為具有上述範圍之折射率者，則並無特別限定。例如可使用硼矽酸鹽系玻璃、磷酸鹽系玻璃、磷酸錫系玻璃、鉍酸鹽系玻璃等。作為硼矽酸鹽系玻璃，可列舉以質量%計，含有30～85%之SiO₂ 、0～30%之Al₂ O₃ 、0～50%之B₂ O₃ 、0～10%之Li₂ O＋Na₂ O＋K₂ O、及0～50%之MgO＋CaO＋SrO＋BaO者。作為磷酸錫系玻璃，可列舉以莫耳%計，含有30～90%之SnO、1～70%之P₂ O₅ 者。玻璃基質7之軟化點較佳為250℃～1000℃之範圍內，更佳為300℃～950℃之範圍內，進而較佳為500℃～900℃之範圍內。若玻璃基質7之軟化點過低，則存在波長轉換構件3之機械強度或化學耐久性降低之情形。又，由於玻璃基質7本身之耐熱性降低，故而存在因自螢光體粒子8產生之熱而發生軟化變形之情形。另一方面，若玻璃基質7之軟化點過高，則存在因製造時之加熱步驟，而螢光體粒子8發生劣化，波長轉換構件3之發光強度降低之情形。又，玻璃基質7較佳為無鹼玻璃。藉此，可抑制螢光體粒子8之失活。再者，就提高波長轉換構件3之化學穩定性及機械強度之觀點而言，玻璃基質7之軟化點較佳為500℃以上、600℃以上、700℃以上、800℃以上、尤其是850℃以上。作為此種玻璃，可列舉硼矽酸鹽系玻璃。其中，若玻璃基質7之軟化點變高，則有焙燒溫度亦升高，結果製造成本變高之傾向。因此，就低價地製造波長轉換構件3之觀點而言，玻璃基質7之軟化點較佳為550℃以下、530℃以下、500℃以下、480℃以下、尤其是460℃以下。作為此種玻璃，可列舉磷酸錫系玻璃、鉍酸鹽系玻璃。螢光體粒子8只要為藉由激發光之入射而出射螢光者，則並無特別限定。作為螢光體粒子8之具體例，例如可列舉選自氧化物螢光體、氮化物螢光體、氮氧化物螢光體、氯化物螢光體、醯氯化物螢光體、硫化物螢光體、氧硫化物螢光體、鹵化物螢光體、硫屬化物螢光體、鋁酸鹽螢光體、鹵磷醯氯化物螢光體及石榴石系化合物螢光體中之1種以上等。於使用藍光作為激發光之情形時，例如可使用以螢光之形式出射綠光、黃光或紅光之螢光體。玻璃基質7中之螢光體粒子8之含量較佳為1～70體積%之範圍內，更佳為1.5～50體積%之範圍內，進而較佳為2～30體積%之範圍內。若螢光體粒子8之含量過少，則存在波長轉換構件3之發光強度變得不充分之情形。另一方面，若螢光體粒子8之含量過多，則存在無法獲得所需發光色之情形。又，存在波長轉換構件3之機械強度降低之情形。於本實施形態中，作為基板5，例如使用可使自光源2發出之光線效率良好地反射之白色LTCC(Low Temperature Co-fired Ceramics，低溫共燒陶瓷)等。具體可列舉氧化鋁、氧化鈦、氧化鈮等無機粉末與玻璃粉末之燒結體。或者可使用氧化鋁或氮化鋁等陶瓷基板。於本實施形態中，可使用樹脂組合物或玻璃陶瓷作為反射層6。作為樹脂組合物，可使用樹脂與陶瓷粉末或玻璃粉末之混合物。作為玻璃陶瓷，可列舉LTCC(Low Temperature Co-fired Ceramics)等。作為玻璃陶瓷之材料，可使用玻璃粉末及陶瓷粉末之混合粉末或結晶性玻璃粉末。作為玻璃粉末，可使用SiO₂ -B₃ O₃ 系玻璃、SiO₂ -RO系玻璃(R表示鹼土金屬)、SiO₂ -Al₂ O₃ 系玻璃、SiO₂ -ZnO系玻璃、SiO₂ -R₂ O系玻璃(R表示鹼金屬)、或SiO₂ -TiO₂ 系玻璃等。該等玻璃粉末可單獨使用亦可併用複數種。作為陶瓷粉末，可使用氧化鋁、氧化鋯或氧化鈦等。該等陶瓷粉末可單獨使用亦可併用複數種。圖4係表示波長轉換構件之基質之折射率與光束之關係的圖。具體係表示自將使用折射率(nd)為1.54之矽酮樹脂作為接著劑所形成之接著劑層4與基質使用折射率不同之材料之波長轉換構件3組合而製作之發光裝置出射之光束、與波長轉換構件3之基質之折射率的關係。光源2係出射波長445nm之激發光之LED。螢光體粒子8為YAG(Yttrium Aluminum Garnet，釔鋁石榴石)。基質A～K如下所述。 A：低折射率矽酮樹脂 B：熔融二氧化矽 C：鹼性硼矽酸玻璃 D：鹼性硼矽酸玻璃 E：鹼性硼矽酸玻璃 F：鹼土族矽酸玻璃 G：矽酸鋇玻璃 H：硼酸鑭玻璃 I：硼酸鑭鈦玻璃 J：硼酸鑭鋅玻璃 K：硼酸鑭釓玻璃將來自使用上述各基質A～K之各發光裝置之出射光之光束(lm)與各基質之折射率(nd)示於表1。 [表1] 圖4係將表1所示之光束(lm)與基質之折射率(nd)製成圖表而表示者。圖4中，以虛線表示接著劑層之折射率(nd)之位置。自表1及圖4明確得知，於基質之折射率與接著劑層之折射率之差為0.1以下之情形時可獲得較高之光束。又，得知若使基質之折射率接近空氣之折射率(≒1.0)，則相較於折射率1.5附近，光束值於低折射率區域反而降低。因此，根據本發明，得知藉由將玻璃基質與接著劑層之折射率之差設為0.1以下，可獲得較高之發光強度。又，得知藉由將玻璃基質與接著劑層之折射率之差設為0.08以下，可獲得更高之發光強度，藉由設為0.07以下，可獲得進而更高之發光強度。Hereinafter, preferred embodiments will be described. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments. In the drawings, members having substantially the same function may be referred to by the same reference numerals. Fig. 1 is a schematic cross-sectional view showing a light-emitting device according to an embodiment of the present invention. Fig. 2 is a schematic plan view showing a light-emitting device according to an embodiment of the present invention. As shown in FIG. 1, the light-emitting device 1 of the present embodiment includes a wavelength conversion member 3, a light source 2 that emits excitation light to the wavelength conversion member 3, and an adhesive layer 4 that is provided between the wavelength conversion member 3 and the light source 2. As shown in FIGS. 1 and 2, in the present embodiment, the light source 2 is provided on the substrate 5. Further, a reflective layer 6 is disposed around the wavelength conversion member 3, the light source 2, and the adhesive layer 4. By arranging the reflective layer 6, the excitation light and the fluorescent light can be reflected to suppress light leakage to the outside, and the light extraction efficiency can be improved. Fig. 3 is a schematic cross-sectional view showing an enlarged wavelength conversion member in a light-emitting device according to an embodiment of the present invention. As shown in FIG. 3, the wavelength conversion member 3 is constituted by dispersing the phosphor particles 8 in the glass substrate 7. As the light source 2, an LED, an LD, or the like can be used. In the case where an LED wafer is used as the light source 2, the LED wafer can be flip-chip mounted. As the flip chip type LED, for example, a sapphire layer is provided on the light-emitting layer. The sapphire layer is disposed on the exit side of the excitation light. An adhesive layer 4 is provided on the light source 2. A wavelength converting member 3 is provided on the adhesive layer 4. The excitation light emitted from the light source 2 is incident on the wavelength conversion member 3 through the adhesive layer 4. The phosphor particles 8 are excited by the excitation light incident on the wavelength conversion member 3, and the fluorescence is emitted from the phosphor particles 8. The synthesized light emitted from the phosphor particles 8 and the excitation light that has passed through the wavelength conversion member 3 is emitted from the wavelength conversion member 3. Further, as described above, in order to improve the light extraction efficiency of the light-emitting device, there is a case where the light extraction efficiency is not necessarily improved even if only the refractive index of the wavelength conversion member is lowered. It is also shown in the test data below. According to the results of investigations by the inventors of the present invention, it has been found that the difference in refractive index between the glass substrate constituting the wavelength converting member and the adhesive layer affects the light extraction efficiency. Specifically, in the present embodiment, the difference in refractive index between the glass substrate 7 of the wavelength conversion member 3 and the adhesive layer 4 is set to 0.1 or less. Thereby, it is possible to suppress the reflection of the excitation light at the interface between the wavelength conversion member 3 and the adhesive layer 4, and it is possible to improve the extraction efficiency of the excitation light and improve the luminous efficiency. Examples of the adhesive constituting the adhesive layer 4 include an anthrone resin type, an epoxy resin type, an ethylene resin type, and an acrylic resin type. The difference in refractive index (nd) between the glass substrate 7 and the adhesive layer 4 is preferably 0.08 or less, more preferably 0.07 or less, and still more preferably 0.04 or less. The refractive index of the subsequent agent layer 4 is preferably in the range of 1.38 to 1.60, more preferably in the range of 1.40 to 1.58. The refractive index of the glass substrate 7 is preferably in the range of 1.48 to 1.60, more preferably in the range of 1.50 to 1.58. The glass substrate 7 can be used as a dispersion medium of the phosphor particles 8 such as an inorganic phosphor, and is not particularly limited as long as it has a refractive index within the above range. For example, a borosilicate type glass, a phosphate type glass, a tin phosphate type glass, a bismuth silicate type glass, etc. can be used. Examples of the borosilicate-based glass include 30 to 85% of SiO ₂ , 0 to 30% of Al ₂ O ₃ , 0 to 50% of B ₂ O ₃ , and 0 to 10% of Li. ₂ O + Na ₂ O + K ₂ O, and 0 to 50% of MgO + CaO + SrO + BaO. Examples of the tin phosphate-based glass include 30 to 90% of SnO and 1 to 70% of P ₂ O ₅ in terms of mol%. The softening point of the glass substrate 7 is preferably in the range of from 250 ° C to 1000 ° C, more preferably in the range of from 300 ° C to 950 ° C, still more preferably in the range of from 500 ° C to 900 ° C. If the softening point of the glass substrate 7 is too low, there is a case where the mechanical strength or chemical durability of the wavelength converting member 3 is lowered. Further, since the heat resistance of the glass substrate 7 itself is lowered, there is a case where softening deformation occurs due to heat generated from the phosphor particles 8. On the other hand, when the softening point of the glass substrate 7 is too high, there is a case where the phosphor particles 8 are deteriorated due to the heating step at the time of production, and the light-emitting intensity of the wavelength conversion member 3 is lowered. Further, the glass substrate 7 is preferably an alkali-free glass. Thereby, the deactivation of the phosphor particles 8 can be suppressed. Further, from the viewpoint of improving the chemical stability and mechanical strength of the wavelength conversion member 3, the softening point of the glass substrate 7 is preferably 500 ° C or higher, 600 ° C or higher, 700 ° C or higher, 800 ° C or higher, especially 850 ° C. the above. As such a glass, a borosilicate type glass is mentioned. However, when the softening point of the glass substrate 7 becomes high, the baking temperature also rises, and the manufacturing cost tends to become high. Therefore, from the viewpoint of producing the wavelength conversion member 3 at a low price, the softening point of the glass substrate 7 is preferably 550 ° C or lower, 530 ° C or lower, 500 ° C or lower, 480 ° C or lower, or particularly 460 ° C or lower. Examples of such a glass include tin phosphate-based glass and silicate-based glass. The phosphor particles 8 are not particularly limited as long as they emit fluorescence by the incidence of the excitation light. Specific examples of the phosphor particles 8 include, for example, an oxide phosphor, a nitride phosphor, an oxynitride phosphor, a chloride phosphor, a ruthenium chloride phosphor, and a sulfide fluorite. One of a light body, an oxysulfide phosphor, a halide phosphor, a chalcogenide phosphor, an aluminate phosphor, a halophosphorus chloride phosphor, and a garnet compound phosphor The above. In the case where blue light is used as the excitation light, for example, a phosphor which emits green light, yellow light or red light in the form of fluorescence can be used. The content of the phosphor particles 8 in the glass substrate 7 is preferably in the range of 1 to 70% by volume, more preferably in the range of 1.5 to 50% by volume, still more preferably in the range of 2 to 30% by volume. When the content of the phosphor particles 8 is too small, the light-emitting intensity of the wavelength conversion member 3 may be insufficient. On the other hand, if the content of the phosphor particles 8 is too large, there is a case where the desired luminescent color cannot be obtained. Further, there is a case where the mechanical strength of the wavelength conversion member 3 is lowered. In the present embodiment, as the substrate 5, for example, white LTCC (Low Temperature Co-fired Ceramics) which can efficiently reflect light emitted from the light source 2 is used. Specific examples thereof include a sintered body of an inorganic powder such as alumina, titania or cerium oxide and a glass powder. Alternatively, a ceramic substrate such as alumina or aluminum nitride can be used. In the present embodiment, a resin composition or a glass ceramic can be used as the reflective layer 6. As the resin composition, a mixture of a resin and a ceramic powder or a glass powder can be used. Examples of the glass ceramics include LTCC (Low Temperature Co-fired Ceramics) and the like. As the material of the glass ceramic, a mixed powder of glass powder and ceramic powder or a crystalline glass powder can be used. As the glass powder, SiO ₂ -B ₃ O ₃ -based glass, SiO ₂ -RO-based glass (R represents an alkaline earth metal), SiO ₂ -Al ₂ O ₃ -based glass, SiO ₂ -ZnO-based glass, or SiO ₂ -R can be used. ₂ O-based glass (R represents an alkali metal) or SiO ₂ -TiO ₂ -based glass. These glass powders may be used singly or in combination of plural kinds. As the ceramic powder, alumina, zirconia, titania or the like can be used. These ceramic powders may be used singly or in combination of plural kinds. Fig. 4 is a view showing the relationship between the refractive index of the matrix of the wavelength converting member and the light beam. Specifically, it is a light beam emitted from a light-emitting device which is formed by combining an adhesive layer 4 formed by using an fluorenone resin having a refractive index (nd) of 1.54 as an adhesive and a wavelength conversion member 3 having a material having a different refractive index as a substrate, The relationship with the refractive index of the matrix of the wavelength converting member 3. The light source 2 is an LED that emits excitation light having a wavelength of 445 nm. The phosphor particles 8 are YAG (Yttrium Aluminum Garnet). The substrates A to K are as follows. A: low refractive index fluorenone resin B: molten cerium oxide C: basic borosilicate glass D: basic borosilicate glass E: basic borosilicate glass F: alkaline earth citrate glass G: bismuth citrate Glass H: barium borate glass I: barium titanate titanium glass J: barium zinc borate glass K: barium borate glass is a refraction of the light beam (lm) from each of the light-emitting devices using the above-mentioned respective substrates A to K and each substrate The rate (nd) is shown in Table 1. [Table 1] Fig. 4 is a graph showing the light beam (lm) shown in Table 1 and the refractive index (nd) of the substrate. In Fig. 4, the position of the refractive index (nd) of the adhesive layer is indicated by a broken line. As is clear from Table 1 and Figure 4, a higher beam can be obtained when the difference between the refractive index of the substrate and the refractive index of the adhesive layer is 0.1 or less. Further, it has been found that when the refractive index of the matrix is close to the refractive index of air (≒1.0), the beam value is decreased in the low refractive index region as compared with the vicinity of the refractive index 1.5. Therefore, according to the present invention, it is found that a high luminous intensity can be obtained by setting the difference in refractive index between the glass substrate and the adhesive layer to 0.1 or less. Further, it has been found that by setting the difference between the refractive indices of the glass substrate and the adhesive layer to 0.08 or less, a higher luminous intensity can be obtained, and by setting it to 0.07 or less, a higher luminous intensity can be obtained.

1‧‧‧發光裝置1‧‧‧Lighting device

2‧‧‧光源2‧‧‧Light source

3‧‧‧波長轉換構件3‧‧‧wavelength conversion member

4‧‧‧接著劑層4‧‧‧ adhesive layer

5‧‧‧基板5‧‧‧Substrate

6‧‧‧反射層6‧‧‧reflective layer

7‧‧‧玻璃基質7‧‧‧ glass substrate

8‧‧‧螢光體粒子8‧‧‧Silver particles

圖1係表示本發明之一實施形態之發光裝置的模式性剖視圖。圖2係表示本發明之一實施形態之發光裝置的模式性俯視圖。圖3係將本發明之一實施形態之發光裝置中之波長轉換構件放大表示的模式性剖視圖。圖4係表示波長轉換構件之基質之折射率與光束之關係的圖。Fig. 1 is a schematic cross-sectional view showing a light-emitting device according to an embodiment of the present invention. Fig. 2 is a schematic plan view showing a light-emitting device according to an embodiment of the present invention. Fig. 3 is a schematic cross-sectional view showing an enlarged wavelength conversion member in a light-emitting device according to an embodiment of the present invention. Fig. 4 is a view showing the relationship between the refractive index of the matrix of the wavelength converting member and the light beam.

Claims

一種發光裝置，其具備：於玻璃基質中分散有螢光體粒子之波長轉換構件、對上述波長轉換構件照射激發光之光源、及設置於上述波長轉換構件與上述光源之間之接著劑層，且上述玻璃基質與上述接著劑層之折射率之差為0.1以下。A light-emitting device comprising: a wavelength conversion member in which a phosphor particle is dispersed in a glass matrix; a light source that emits excitation light to the wavelength conversion member; and an adhesive layer provided between the wavelength conversion member and the light source, Further, the difference between the refractive indices of the glass substrate and the adhesive layer is 0.1 or less.

如請求項1之發光裝置，其中上述玻璃基質之折射率為1.6以下。The light-emitting device of claim 1, wherein the glass substrate has a refractive index of 1.6 or less.

如請求項1或2之發光裝置，其中上述接著劑層係由矽酮樹脂構成。The light-emitting device of claim 1 or 2, wherein the above-mentioned adhesive layer is composed of an anthrone resin.

如請求項1至3中任一項之發光裝置，其中上述玻璃基質之折射率為1.48以上。The light-emitting device according to any one of claims 1 to 3, wherein the glass substrate has a refractive index of 1.48 or more.

如請求項1至4中任一項之發光裝置，其中於上述波長轉換構件、上述光源、及上述接著劑層之周圍具備反射層。The light-emitting device according to any one of claims 1 to 4, wherein a reflection layer is provided around the wavelength conversion member, the light source, and the adhesive layer.

如請求項1至5中任一項之發光裝置，其中上述反射層係由樹脂組合物或玻璃陶瓷構成。The light-emitting device according to any one of claims 1 to 5, wherein the reflective layer is composed of a resin composition or a glass ceramic.