200928216 九、發明說明： 【發明所屬之技術領域】 '本發明關於一種照明裝置，尤其是關於發光二極體燈 具。 【先前技術】 目前，發光二極體（Light Emitting Diode，LED)因具光 質佳、發光效率高、長壽命、低耗能等特性而逐漸取代冷 陰極螢光燈（Cold Cathode Fluorescent Lamp，CCFL)作為照 ❹明裝置之發光元件，廣泛應用于交通指揮燈、汽車車燈、 室内照明燈、路燈等。 然而，LED本身發出光線的波長頻譜極窄，要使用LED 製作照明燈具，通常要通過混合多種色光以獲得白光。例 如，先利用藍光與螢光粉搭配組合成白光，再搭配紅色光 提高其演色性，並同時提高其色溫度，或者利用藍光、藍 綠色光、橘色光以及紅光組合成白光。然而，雖然搭配各 種色光能獲得白光，但由於琥珀色LED、紅光LED、黃光 WLED、橘色光LED等LED之溫度特性變異很大，特別是使 用AlInGaP與GaAs材料之LED其溫度變化影響其發光特 性甚大，當由室溫（約20°C)升高至80°C時，其發光強度會 衰減約45%，使得LED照明燈具之顏色、色溫度、混光後 之照度都大幅改變。因此本發明希望能設計一種工作溫度 穩定，從而產生穩定白光之發光二極體燈具。 【發明内容】 有鑒於此，有必要提供一種能輸出穩定白光之發光二 6 200928216 .極體燈具。 一種發光二極體燈具，包括一第一發光二極體及一第 二發光二極體，其中第一發光二極體之發光強度隨溫度之 變化小於第二發光二極體，該發光二極體燈具還包括分離 設置之第一及第二散熱器，其中第一散熱器與第一發光二 極體熱性連接，第二散熱器與第二發光二極體熱性連接， 該第二散熱器之散熱效率高於第一散熱器之散熱效率。 上述發光二極體燈具針對不同之發光二極體之不同溫 ®度特性，利用分離式散熱器，使不同發光二極體均工作在 適當之溫度，從而輸出穩定之白光。 【實施方式】 下面將結合附圖對本發明實施例作進一步之詳細說 明。如圖1所示，本發明發光二極體（LightEmittingDiode, LED)燈具100包括一基板30，設置於基板30上之LED陣 列，設置於基板30上之散熱裝置，及一罩設於LED陣列 ❹上之反射罩40。 該實施例中，基板30為一金屬芯印刷電路板（Metal Core PCB，MCPCB)，該基板30通過對一鋁板進行絕緣處 理，即於其表面上形成一絕緣層（圖未示），而後於該絕緣層 上建立一線路層而形成。可以理解的，基板30是為提供線 路以安裝該LED陣列，該基板30也可以是一普通之印刷 電路板（printed circuit board，PCB)、陶究電路板等。相對于 普通之電路板，本實施例金屬芯印刷電路板具有更高之導 熱係數，可以快速將LED產生之熱量傳導出去。 200928216 所述LED陣列包括複數排布於基板30上之顏色不同 之LED，所述LED通過打線方式（wire bonding)或者覆晶方 式（flip chip)與基板30之線路實現電性連接。該實施例中， 所述LED陣列包括兩種LED，即白光LED部分60與紅光 LED部分50，白光LED部分60與紅.光LED部分50所產 生之光線在反射罩40内混合，產生白光照明。為達成高演 色性之白光照明燈具100，白光LED部分60採用藍光LED 晶片，該藍光LED晶片之表面設有黃色螢光粉，從而由藍 〇光LED晶片激發黃色螢光粉產生黃光，藍光與黃光相混合 而產生白光。該藍光LED晶片之材料可為GalnN(氮化銦鎵） 或GaN(氮化鎵），波長在450〜47〇nm。紅光LED部分50採 用紅光LED晶片，其材料可為AlInGaP(鋁銦鎵磷化物）或 GaAs(石申化鎵），波長610〜635nm，通過紅光與白光之搭配， 混合後燈具100所產生白光之演色性可達90以上。 由於LED在工作時部分電能轉化為熱能，導致LED之 0溫度升高，而在溫度上升時，各色LED之發光強度與波長 之變動並不相同，如圖2所示為三種不同顏色LED之發光 強度與溫度之關係圖，其中Tb線所示為藍光LED之發光 強度隨溫度之變化，Tr線表示紅光LED之發光強度隨溫度 之變化，Tg線表示綠光LED之發光強度隨溫度之變化，由 圖示可知，隨溫度之變化藍光LED之發光強度改變最小， 基本上不受溫度變化之影響；綠光LED在溫度由20°C上升 至80°C時，發光強度大約下降15%，而紅光LED在溫度由 20°C上升至40°C時，發光強度已大約下降15%。因此當溫 200928216 .度上升時，應首先控制紅光LED之溫度，當綠光LED之環 境溫度達到80°C時，若能控制紅光LED在40°C以下，即 能夠將混色後白光之變異控制於較低之範圍。 根據各色LED之溫度特徵，本發明LED燈具100之散 熱裝置包括對應各色LED設置之多個.相分離之散熱器。該 實施例中，對應白光LED部分60與紅光LED部分50分別 設置一散熱器，即第一、第二散熱器10、20,該兩散熱器 均為鋁材質散熱器，每一散熱器10、20包括一底板170、 ❹270及複數散熱鰭片180、280，每一底板170、270均呈台 體狀，包括一底面172、272及與該底面172、272相對之 一頂面174、274，所述底面172、272貼設於基板30上， 所述散熱鰭片180、280自頂面174、274向上延伸。其中 第一散熱器10之底板170之橫截面積沿厚度方向自底面 172向頂面174逐漸減小，而第二散熱器20之底板270之 橫截面積沿厚度方向自底面272向頂面274逐漸增加，從 ❹而第一散熱器10底板170頂面174之面積小於其底面172 之面積，而第二散熱器20底板270頂面274之面積大於其 底面272之面積。為保證鰭片180、280能將熱量有效之散 發至環境中，設置於各散熱器10、20之頂面174、274之 鰭片180、280之密度相當，從而相對於相應之底面172、 272而言，第二散熱器20相較於第一散熱器10單位面積内 具有更多之散熱鰭片，第二散熱器20相較於第一散熱器10 具有更高之散熱效率。而各散熱器10、20之底面172、272 與各色LED之設置相對應，從而紅光LED部分50相對于 9 200928216 白光LED部分60具有更多散熱鰭片，有助於熱量之快速 散發’維持紅光LED部分50在較低之溫度下工作，保證 紅光LED部分50之發光強度與穩定性，從而維持LED燈 具100所形成白光之穩定性。 如圖3所示為本發明LED燈具2Q0之另一實施例示意 圖’與前一實施例相同的是同樣通過於反射罩24〇内混合 白光LED部分260與紅光LED部分250之光線形成白光， 白光LED部分60採用藍光LED晶片，該藍光LED晶片之 ^表面設有黃色螢光粉，紅光led部分50採用紅光LED晶 片。所述白光LED部分260與紅光LED部分250均電連接 於金屬芯電路基板230上。對應白光LED部分260與紅光 LED部分250分別設置一散熱器210、220，其不同之處在 於：該實施例中，兩散熱器210、220之材料不同，其中對 應白光LED部分260之第一散熱器210之材質為鋁，對應 紅光LED部分250之第二散熱器220之材質為銅，眾所周 ❹知’同體積之銅其熱容為同體積之鋁之1.8倍，而銅之熱傳 係數約為鋁之1.6倍，因此第一散熱器210採用鋁材、第二 散熱器220採用銅材’第二散熱器220相較於第一散熱器 210具有更高之散熱效率’可有效增強紅光LED部分250 之散熱效率’使紅光LED部分250維持在較低之工作溫度。 如圖4所示為本發明LED燈具300之再一實施例示意 圖’該實施例中’通過混合藍光LED、綠光LED、黃光LED 與紅光LED四種不同比例之色光達成高演色性之白光照明 燈，而不採用螢光粉。其中藍光LED與綠光LED構成第一 200928216 發光部分360,該藍光LED與綠光LED之晶片均採用GalnN 或GaN材料，藍光LED之波長在450〜470nm，綠光LED 之波長在510〜540nm;紅光LED與黃光LED構成第二發光 部分350，紅光LED與黃光LED之晶片均採用AlInGaP或 GaAs材料，紅光LED之波長為610〜635nm，黃光LED之 波長為580〜600nm。所有LED之外側罩設一散射片340， 從而各色LED所產生之光線經散射片340混光後產生白 光，本實施例LED燈具300能夠使演色性達到95以上。 〇同樣，所述四色LED均設置於金屬芯印刷電路基板330 上，基板330之另一側同時設置兩鋁材質散熱器310、320, 每一散熱器310、320上均設置複數散熱鰭片380、390,其 中第一散熱器310與藍光LED及綠光LED(即第一發光部分 360)對應設置，第二散熱器320與紅光LED及黃光LED(即 第二發光部分350)對應設置。兩散熱器310、320之不同之 處在於·第一散熱器310之鰭片380之長度小於第二散熱 ❹器320之鰭片390之長度。從而第二散熱器320具有更大 之散熱面積’相較於第一散熱器310具有更高之散熱效率， 從而使紅光LED及黃光LED維持在較低之工作溫度。 如上所述’本發明LED燈具根據各種LED不同之溫度 特性’設置散熱效率不同之散熱器，可有效保證各色led 均工作在適當之溫度，維持各色LED之發光效率，進而獲 得更為穩定之白光照明。以上僅列舉本發明led燈具之幾 種具體實施方式，本領域技術人員還可在本發明精神内做 其他變化’只要其不偏離本發明之技術效果，都應包含在 11 200928216 本發明所要求保護之範圍之内，如各色LED之組合設置， 可根據需要而變更。而散熱器材質之選擇並不限於鋁、銅， 其他導熱性能較佳之材料，如銀等均可作為散熱器之材 料，同樣，散熱器之設計可綜合考慮鰭片之高度、底座之 寬度以及材料之選擇，只要能滿足散熱需求，維持適當之 工作溫度即可。 綜上所述，本發明確已符合發明專利之要件，遂依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 ®式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1為本發明發光二極體燈具之組合示意圖； 圖2為紅光、藍光、綠光發光二極體之發光強度與溫 度之關係圖； q 圖3為本發明發光二極體燈具另一實施例示意圖； 圖4為本發明發光二極體燈具再一實施例示意圖。 【主要元件符號說明】 第一散熱器 10、210、310 LED 燈具 100、200、300 底板 170、270 底面 頂面 172 ' 272 174 、 274 散熱鰭片 180、280、380、390 12 320 200928216 第二散熱器 20 、 220 基板 30 、 230 散射片 反射罩 40 紅光LED部分 50、250 白光LED部分 60 ' 260 330 340 240 350 360200928216 IX. Description of the invention: [Technical field to which the invention pertains] 'The present invention relates to a lighting device, and more particularly to a light-emitting diode lamp. [Prior Art] At present, the Light Emitting Diode (LED) is gradually replacing the Cold Cathode Fluorescent Lamp (CCFL) due to its high light quality, high luminous efficiency, long life and low energy consumption. As a light-emitting element of the device, it is widely used in traffic light, car lights, indoor lights, street lights, and the like. However, the wavelength spectrum of the light emitted by the LED itself is extremely narrow. To use LEDs to make lighting fixtures, it is usually necessary to mix a plurality of colored lights to obtain white light. For example, use blue light and phosphor powder to combine white light, then use red light to improve its color rendering, and at the same time increase its color temperature, or use blue light, blue-green light, orange light and red light to form white light. However, although white light can be obtained with various color lights, the temperature characteristics of LEDs such as amber LED, red LED, yellow LED, and orange LED vary greatly, especially the temperature change of LEDs using AlInGaP and GaAs materials. The luminescence property is very large. When it is raised from room temperature (about 20 ° C) to 80 ° C, its luminescence intensity is attenuated by about 45%, so that the color, color temperature and illuminance of the LED lighting fixture are greatly changed. Therefore, the present invention contemplates the design of a light-emitting diode lamp in which the operating temperature is stabilized to produce a stable white light. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a light-emitting device capable of outputting stable white light. A light-emitting diode lamp includes a first light-emitting diode and a second light-emitting diode, wherein a light-emitting intensity of the first light-emitting diode is smaller than a second light-emitting diode with a change in temperature, and the light-emitting diode The body lamp further includes a first and a second heat sink disposed separately, wherein the first heat sink is thermally connected to the first light emitting diode, and the second heat sink is thermally connected to the second light emitting diode, wherein the second heat sink is The heat dissipation efficiency is higher than the heat dissipation efficiency of the first heat sink. The above-mentioned light-emitting diode lamp utilizes a separate heat sink for different temperature characteristics of different light-emitting diodes, so that different light-emitting diodes are operated at an appropriate temperature, thereby outputting stable white light. [Embodiment] Hereinafter, embodiments of the present invention will be further described in detail with reference to the accompanying drawings. As shown in FIG. 1 , a light emitting diode (LED) lamp 100 of the present invention includes a substrate 30, an LED array disposed on the substrate 30, a heat dissipating device disposed on the substrate 30, and a cover disposed on the LED array. The reflector 40 is placed thereon. In this embodiment, the substrate 30 is a metal core printed circuit board (MCPCB). The substrate 30 is insulated by an aluminum plate, that is, an insulating layer (not shown) is formed on the surface thereof, and then A wiring layer is formed on the insulating layer. It can be understood that the substrate 30 is provided with a line for mounting the LED array. The substrate 30 can also be a common printed circuit board (PCB), a ceramic circuit board or the like. Compared with the conventional circuit board, the metal core printed circuit board of the embodiment has a higher thermal conductivity coefficient, and can quickly conduct heat generated by the LED. 200928216 The LED array includes a plurality of LEDs of different colors arranged on the substrate 30, and the LEDs are electrically connected to the lines of the substrate 30 by wire bonding or flip chip. In this embodiment, the LED array includes two types of LEDs, namely a white LED portion 60 and a red LED portion 50. The light generated by the white LED portion 60 and the red LED portion 50 is mixed in the reflective cover 40 to produce white light. illumination. In order to achieve a high color rendering white light fixture 100, the white LED portion 60 uses a blue LED chip having a yellow phosphor powder on the surface thereof, thereby exciting the yellow phosphor to generate yellow light and blue light from the blue LED chip. Mixed with yellow light to produce white light. The material of the blue LED chip may be GalnN (indium gallium nitride) or GaN (gallium nitride) with a wavelength of 450 to 47 〇 nm. The red LED portion 50 is a red LED chip, and the material thereof may be AlInGaP (aluminum indium gallium phosphide) or GaAs (lithium gallium), with a wavelength of 610 to 635 nm, which is matched by red light and white light, and the mixed light fixture 100 The color rendering of white light can reach more than 90. Since the LED is converted into thermal energy during operation, the temperature of the LED 0 increases, and when the temperature rises, the luminous intensity of each LED does not change the same as the wavelength, as shown in FIG. 2, the illumination of three different color LEDs The relationship between intensity and temperature, in which the Tb line shows the change of the luminous intensity of the blue LED with temperature, the Tr line represents the change of the luminous intensity of the red LED with temperature, and the Tg line represents the change of the luminous intensity of the green LED with temperature. As can be seen from the figure, the change of the luminous intensity of the blue LED with the change of temperature is the smallest, and is basically not affected by the temperature change; when the temperature of the green LED rises from 20 ° C to 80 ° C, the luminous intensity decreases by about 15%. When the red LED rises from 20 ° C to 40 ° C, the luminous intensity has dropped by about 15%. Therefore, when the temperature rises to 200928216 degrees, the temperature of the red LED should be controlled first. When the ambient temperature of the green LED reaches 80 °C, if the red LED can be controlled below 40 °C, the white light can be mixed. The variation is controlled in the lower range. According to the temperature characteristics of the LEDs of the respective colors, the heat dissipating device of the LED lamp 100 of the present invention comprises a plurality of phase-separated heat sinks corresponding to the LEDs of the respective colors. In this embodiment, a corresponding heat sink, that is, first and second heat sinks 10 and 20, is disposed respectively corresponding to the white LED portion 60 and the red LED portion 50. The two heat sinks are aluminum heat sinks, and each heat sink 10 20 includes a bottom plate 170, a crucible 270, and a plurality of heat dissipation fins 180 and 280. Each of the bottom plates 170 and 270 has a base shape, and includes a bottom surface 172, 272 and a top surface 174, 274 opposite to the bottom surface 172, 272. The bottom surfaces 172 and 272 are attached to the substrate 30, and the heat dissipation fins 180 and 280 extend upward from the top surfaces 174 and 274. The cross-sectional area of the bottom plate 170 of the first heat sink 10 gradually decreases from the bottom surface 172 toward the top surface 174 in the thickness direction, and the cross-sectional area of the bottom plate 270 of the second heat sink 20 decreases from the bottom surface 272 to the top surface 274 along the thickness direction. Gradually increasing, the area of the top surface 174 of the bottom plate 170 of the first heat sink 10 is smaller than the area of the bottom surface 172, and the area of the top surface 274 of the bottom plate 270 of the second heat sink 20 is larger than the area of the bottom surface 272. In order to ensure that the fins 180, 280 can effectively dissipate heat into the environment, the densities 180, 280 disposed on the top surfaces 174, 274 of the heat sinks 10, 20 are equivalent to each other, thereby being opposite to the corresponding bottom surfaces 172, 272. In other words, the second heat sink 20 has more heat dissipation fins than the first heat sink 10 , and the second heat sink 20 has higher heat dissipation efficiency than the first heat sink 10 . The bottom surfaces 172, 272 of the heat sinks 10, 20 correspond to the settings of the LEDs of the respective colors, so that the red LED portion 50 has more heat-dissipating fins relative to the 9 200928216 white LED portion 60, which contributes to the rapid dissipation of heat. The red LED portion 50 operates at a lower temperature to ensure the illumination intensity and stability of the red LED portion 50, thereby maintaining the stability of the white light formed by the LED fixture 100. FIG. 3 is a schematic view showing another embodiment of the LED lamp 2Q0 of the present invention. The same as the previous embodiment, the white light is also formed by mixing the white LED portion 260 and the red LED portion 250 in the reflector 24 . The white LED portion 60 employs a blue LED chip, the surface of which is provided with yellow phosphor powder, and the red LED portion 50 is a red LED chip. The white LED portion 260 and the red LED portion 250 are electrically connected to the metal core circuit substrate 230. Corresponding to the white LED portion 260 and the red LED portion 250, a heat sink 210, 220 is respectively disposed, which is different in the embodiment, the materials of the two heat sinks 210, 220 are different, and the first one corresponding to the white LED portion 260 The material of the heat sink 210 is aluminum, and the material of the second heat sink 220 corresponding to the red LED portion 250 is copper. It is known that the heat capacity of the same volume of copper is 1.8 times that of the same volume of aluminum, and copper The heat transfer coefficient is about 1.6 times that of aluminum, so the first heat sink 210 is made of aluminum, and the second heat sink 220 is made of copper. The second heat sink 220 has higher heat dissipation efficiency than the first heat sink 210. Effectively enhancing the heat dissipation efficiency of the red LED portion 250 'maintains the red LED portion 250 at a lower operating temperature. FIG. 4 is a schematic view showing still another embodiment of the LED lamp 300 of the present invention. In this embodiment, a high color rendering property is achieved by mixing four different proportions of color light of a blue LED, a green LED, a yellow LED, and a red LED. White light instead of fluorescent powder. The blue LED and the green LED constitute the first 200928216 illumination part 360, and the blue LED and the green LED chip are both made of GalnN or GaN material, the wavelength of the blue LED is 450~470nm, and the wavelength of the green LED is 510~540nm; The red LED and the yellow LED form a second light emitting portion 350. The red LED and the yellow LED wafer are both made of AlInGaP or GaAs material, the red LED has a wavelength of 610 to 635 nm, and the yellow LED has a wavelength of 580 to 600 nm. All of the LEDs are provided with a diffusion sheet 340 on the outer side of the LED, so that the light generated by the LEDs of the respective colors is mixed by the diffusion sheet 340 to generate white light. The LED lamp 300 of the embodiment can achieve a color rendering of 95 or more. Similarly, the four color LEDs are disposed on the metal core printed circuit board 330. The other side of the substrate 330 is provided with two aluminum heat sinks 310 and 320, and each of the heat sinks 310 and 320 is provided with a plurality of heat sink fins. 380, 390, wherein the first heat sink 310 is disposed corresponding to the blue LED and the green LED (ie, the first light emitting portion 360), and the second heat sink 320 corresponds to the red LED and the yellow LED (ie, the second light emitting portion 350) Settings. The difference between the two heat sinks 310, 320 is that the length of the fins 380 of the first heat sink 310 is smaller than the length of the fins 390 of the second heat sink 320. Thus, the second heat sink 320 has a larger heat dissipation area' having a higher heat dissipation efficiency than the first heat sink 310, thereby maintaining the red LED and the yellow LED at a lower operating temperature. As described above, the LED lamp of the present invention sets a heat sink with different heat dissipation efficiency according to different temperature characteristics of various LEDs, and can effectively ensure that the LEDs of each color work at an appropriate temperature, maintain the luminous efficiency of each color LED, and thereby obtain a more stable white light. illumination. Only a few specific embodiments of the LED lamp of the present invention are listed above, and those skilled in the art can make other changes within the spirit of the present invention. As long as they do not deviate from the technical effects of the present invention, they should be included in 11 200928216. Within the range, such as the combination of LEDs of various colors, can be changed as needed. The choice of heat sink material is not limited to aluminum or copper. Other materials with better thermal conductivity, such as silver, can be used as the material of the heat sink. Similarly, the design of the heat sink can take into account the height of the fin, the width of the base and the material. The choice, as long as it can meet the cooling needs, maintain the appropriate working temperature. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application in this case. Equivalent modifications or variations made by persons skilled in the art in light of the present invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the combination of the luminous intensity of the red, blue and green light emitting diodes; FIG. 2 is a diagram showing the relationship between the luminous intensity of the red, blue and green light emitting diodes; A schematic diagram of another embodiment of a diode lamp; FIG. 4 is a schematic view of still another embodiment of a light-emitting diode lamp according to the present invention. [Main component symbol description] First heat sink 10, 210, 310 LED lamp 100, 200, 300 Bottom plate 170, 270 Bottom top surface 172 ' 272 174, 274 Heat sink fins 180, 280, 380, 390 12 320 200928216 Second Heat sink 20, 220 substrate 30, 230 diffuser reflector 40 red LED portion 50, 250 white LED portion 60 ' 260 330 340 240 350 360
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