JP2010177368A - Method for manufacturing led device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a white LED device, which achieves both color characteristics and color rendering properties while allowing the improvement of manufacturability and the reduction in cost. <P>SOLUTION: In the method for manufacturing an LED device, color rendering properties are adjusted by selecting a main wavelength of a blue LED chip 21 so that a difference between the minimum main wavelength and the maximum main wavelength of the blue LED chip 21 is ≤10 nm, in the state where a mixture ratio of phosphors corresponding to a plurality of colors of a phosphor portion 13 is fixed. Since color rendering properties are finely adjusted without the necessity of preparing specifications for mixture ratios of large numbers of phosphors, both color characteristics and color rendering properties are achieved while allowing the improvement in manufacturability and the reduction in cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an LED device including an LED chip and a phosphor excited by light emitted from the LED chip.

  2. Description of the Related Art Conventionally, light emitting diodes (LEDs), such as liquid crystal displays, mobile phones, information terminal backlights, and indoor / outdoor announcements, have been dramatically expanded. And LEDs are attracting attention not only for industrial fields but also for general lighting because of their features such as long life, low power consumption, impact resistance, high-speed response, high purity display color, lightness, thinness, etc. Yes.

  For example, as a typical method for constructing an LED device that emits white light, (1) a three-LED method using three color LEDs constituting primary colors such as red, green, and blue, and (2) a blue LED and yellow A method using a phosphor (YAG, etc.) and a phosphor blended with a red phosphor, and (3) an ultraviolet LED (hereinafter referred to as UV-LED), a blue phosphor, a green phosphor and a red phosphor (hereinafter referred to as a UV phosphor). There are three types using a phosphor blended with BGR phosphor).

  As such an LED device, for example, a blue LED chip is provided in a cup shape such as an SMD or a shell type, and in addition to a type in which a phosphor-containing resin is applied, for the purpose of increasing the brightness, a substrate (board) is used. A structure of a chip on board (COB) having a plurality of blue LED chips mounted thereon has been developed and attracts attention.

  In addition to high efficiency, the characteristics required of such LED devices for general illumination include correlated color temperature as a light source color developed by HID lamps, light bulbs, and fluorescent lamps that are current lamps. Lineups such as 6600K, 5000K, 4200K, and 3000K (2800K) are required. Furthermore, color rendering (for example, average color rendering index Ra) is also important as an indicator of color appearance, and lineups such as Ra 80 to 85 or Ra 90 or higher with a fluorescent lamp as a benchmark are required. In order to meet the requirements of these light characteristics, generally, a method of combining the excitation LED and the phosphor of (2) and (3) above is adopted.

  Usually, in order to improve the color rendering, the red color emission from the 620 nm red phosphor is added to the yellow phosphor such as YAG which emits yellow from 540 nm to 560 nm by blue light emission from the chip, and the color rendering property is excellent. A method of adjusting the white light is taken. In recent years, green phosphors (around 500 nm) are also used, and by filling the valley of the spectral distribution generated between blue light emission and fluorescent light emission from the phosphor, it is closer to the spectral spectrum of sunlight and further improves color rendering. A method of aiming at (around Ra95) has also been taken (see, for example, Patent Document 1).

JP 2006-303140 A (page 5-7, FIG. 1)

  As described above, the LED considering the lighting application is required to have many lineups of high efficiency and correlated color temperature and color rendering. Therefore, in order to cope with these, it is indispensable to prepare enormous amounts of phosphor specifications in which a plurality of types of phosphors are precisely controlled when blending phosphors.

  However, in order to deal with such a wide range of light characteristics for recent LEDs, it is inevitably necessary to prepare a huge amount of phosphor specifications, complicated information management and maintenance, and changing phosphor coating liquid during production There are problems in manufacturing and cost such as time loss due to frequency.

  In fact, it is particularly difficult to control both the color characteristics and the color rendering in the phosphor system. For example, when a red phosphor is simply added in an attempt to improve the color rendering, the correlated color temperature is reduced to a low color temperature. It will shift to the side. For this reason, a yellow phosphor or a green phosphor is also added for adjustment, but there is an absorption relationship between the red phosphor, the yellow phosphor, and the green phosphor, and it is not simply an addition / subtraction. Therefore, when blending phosphors, a plurality of types of phosphors must be precisely controlled and blended.

  This invention is made in view of such a point, and it aims at providing the manufacturing method of the LED device which made the color characteristic and color rendering property compatible, enabling improvement of productivity and cost reduction. .

  The LED device manufacturing method according to claim 1, wherein an LED chip disposed on a substrate and phosphors corresponding to a plurality of colors excited by light emission of the LED chip are blended at a predetermined blending ratio. A method for manufacturing an LED device including a phosphor portion covering the phosphor portion, wherein the difference between the minimum dominant wavelength and the maximum dominant wavelength of the LED chip is within 10 nm with the phosphor compounding ratio of the phosphor portion fixed. Thus, the color rendering properties are adjusted by selecting the dominant wavelength of the LED chip.

  A plurality of types of LED chips are preferably selected from blue LED chips having a dominant wavelength of 450 nm to 465 nm so that the difference between the minimum dominant wavelength and the maximum dominant wavelength is within 10 nm.

  Examples of the phosphor used in the phosphor part include a green phosphor, a yellow phosphor, and a red phosphor.

  The blending ratio of the phosphors refers to the ratio of each phosphor to the resin or the like to be dispersed in which the phosphor is dispersed.

  The manufacturing method of the LED device according to claim 2 is the manufacturing method of the LED device according to claim 1, wherein the main wavelength is a plurality of kinds of LED chips having a plurality of different main wavelengths with respect to the phosphor mixture ratio. It is set so as to be within a predetermined color temperature range with respect to the LED chip having the median value.

  Among a plurality of types of LED chips having a plurality of different main wavelengths, for example, an LED chip whose main wavelength is the median value is, for example, that the main wavelength is the minimum value and the maximum value of the main wavelengths of the plurality of types of LED chips. The value that is between.

  According to the manufacturing method of the LED device according to claim 1, the difference between the minimum dominant wavelength and the maximum dominant wavelength of the LED chip is within 10 nm in a state where the phosphor mixture ratio of the phosphor portion is fixed. By adjusting the color rendering property by selecting the dominant wavelength of the LED chip, it becomes possible to finely adjust the color rendering property without preparing a specification of the enormous phosphor blending ratio. Both color characteristics and color rendering can be achieved while enabling cost reduction.

  According to the manufacturing method of the LED device according to claim 2, in addition to the effect of the manufacturing method of the LED device according to claim 1, a plurality of types of LED chips having a plurality of main wavelengths different from each other in the blending ratio of the phosphors Of these, by setting the LED wavelength with the dominant wavelength to be within the predetermined color temperature range for the LED chip having the median value, color rendering can be achieved while using any of a plurality of types of LED chips within the desired color temperature range. Only sex can be adjusted.

It is sectional drawing of the LED device which shows one embodiment of this invention. It is a top view of a LED device same as the above. It is a table | surface which shows the characteristic of Examples 1-3 same as the above. It is a graph which shows the characteristic of Examples 1-3 same as the above. It is a graph which shows the spectral distribution of Examples 1-3 same as the above. It is a graph which shows the relationship between the wavelength of the LED chip of Examples 1-3 same as the above, and color rendering properties.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 is a sectional view of the LED device, FIG. 2 is a plan view of the LED device, FIG. 3 is a table showing the characteristics of Examples 1 to 3 of the LED device, and FIG. 4 is a graph showing the characteristics of Examples 1 to 3, FIG. 5 is a graph showing the spectral distribution of Examples 1 to 3, and FIG. 6 is a graph showing the relationship between the wavelength of the LED chips of Examples 1 to 3 and the color rendering properties.

  In FIG. 1 and FIG. 2, reference numeral 11 denotes a white LED device which is an LED device for general illumination, for example. This white LED device has a rectangular substrate 12 in plan view and a fluorescent light formed on the substrate 12. And a body part 13.

  The substrate 12 includes, for example, an aluminum layer 15 as a substrate body, an insulating layer 16 formed on one main surface of the aluminum layer 15, a copper pattern 17 formed on the insulating layer 16, and the copper pattern 17 Plating treatment layers 18 and 19 formed so as to be covered, and blue LED chips 21 which are a plurality of bare chips as LED chips each fixed on the plating treatment layer 19 via a die bonding material 20. And in this board | substrate 12, the circular-shaped arrangement | positioning part 22 by the planar view by which the blue LED chip 21 is arrange | positioned, and the peripheral part 23 located around this arrangement | positioning part 22 are formed, In this peripheral part 23, Connectors 24 and 25 are arranged.

  The aluminum layer 15 has a thickness of about 1 mm, for example.

  The insulating layer 16 is, for example, a layer having a thickness of 80 μm and a thermal conductivity of about 1.0 W / m · K.

  The copper pattern 17 has a thickness of, for example, about 35 μm, and includes each blue LED chip 21 and a protection circuit component (not shown) (for example, a resistor, a Zener diode, or a capacitor) that is solder-mounted on the peripheral portion 23. It is an electrical connection.

  The plating layer 18 is, for example, an electroless nickel (Ni) plating layer, and has a thickness of about 3.0 μm to 5.0 μm.

  The plating layer 19 is, for example, an electroless silver (Ag) plating layer, and has a thickness of about 0.3 μm to 0.7 μm.

  The die bond material 20 is an adhesive composed of, for example, a transparent resin such as silicone.

  The blue LED chip 21 is a semiconductor chip in which a blue monochromatic light emitting semiconductor light emitting layer is laminated on an element substrate such as a sapphire substrate fixed by a die bond material 20, and electrodes are arranged on the semiconductor light emitting layer so as to be separated from each other. And electrically connected to a conductor (not shown) via bonding wires 26 connected to the electrodes, for example, all the blue LED chips 21 are electrically connected in series. The blue LED chips 21 have a difference between the minimum main wavelength and the maximum main wavelength within 10 nm from among a plurality of types of blue LED chips 21 having different main wavelengths (preferably 450 nm to 465 nm). By selecting several types as described above, the correlated color temperature and the color rendering properties (for example, the average color rendering index Ra) of the white LED device 11 can be adjusted to each desired range. The blue LED chip 21 has a higher color rendering property as the wavelength is longer at the same correlated color temperature.

  The connectors 24 and 25 are for connecting the blue LED chip 21 to an external circuit (not shown).

  The phosphor portion 13 includes an annular frame portion 31 surrounding the arrangement portion 22 of the substrate 12, and a sealing resin that fills the frame portion 31 and covers the entire arrangement portion 22 (blue LED chip 21). Part 32.

  The frame portion 31 is formed on the plating layer 19 to a thickness of about 1 mm, for example.

  The sealing resin portion 32 is configured using a phosphor coating liquid formed of a resin such as transparent silicone in which phosphors (not shown) corresponding to a plurality of colors are mixed.

  Here, the phosphor emits light of a predetermined color by being excited by a part of the light emitted from the blue LED chip 21, and in the present embodiment, yellow light and red light with respect to blue light. Alternatively, a yellow phosphor, a red phosphor, or a green phosphor that respectively emits green light is blended at a predetermined blending ratio that is set in advance.

  In addition, the blending ratio of each phosphor is set to be a predetermined color temperature range targeted for the blue LED chip 21 having a median dominant wavelength in the dominant wavelength range. In addition, when the blue LED chip 21 is selected as an even number of four or more types having different main wavelengths, one of the two types of the main wavelengths having the intermediate value is the intermediate value. The blending ratio of the phosphors may be set as follows. For example, when four types of blue LED chips 21 having main wavelengths a to d (a <b <c <d) are selected, the blue LED chip 21 having either the main wavelength b or c is selected. Thus, the blending ratio of the phosphors may be set so that a predetermined color temperature range as a target is obtained.

  Next, the manufacturing method of the one embodiment will be described.

  First, an insulating layer 16 and copper are formed on the aluminum layer 15 and subjected to various plating processes, followed by patterning to form a copper pattern 17 and plating layers 18 and 19.

  Next, the blue LED chip 21 is fixedly disposed on the plating layer 19 via the die bonding material 20. At this time, the blue LED chip 21 selects a main wavelength corresponding to a desired color rendering property from a plurality of different types in which the difference between the minimum value and the maximum value of the main wavelength is within 10 nm.

  Thereafter, a frame part 31 is formed around the arrangement part 22, and a phosphor coating liquid such as a transparent two-pack type silicone in which various phosphors are blended in the frame part 31 at a predetermined blending ratio. Is filled and cured to form the sealing resin portion 32, and the white LED device 11 is completed.

  3 to 6 show the color temperature characteristics and the like for the first to third embodiments.

  In Example 1, the main wavelength (λd) of the blue LED chip 21 is 454 nm (minimum value), 456 nm (median value), and 461 nm (maximum value), respectively. For example, using a phosphor coating liquid in which a green phosphor having a peak wavelength at about 520 nm, a yellow phosphor having a peak wavelength at about 570 nm, and a red phosphor having a peak wavelength at 650 nm are blended at a predetermined blending ratio. The white LED device 11 having a correlated color temperature (Tc) of 3200K and a color rendering property (Ra) of 80 is produced. In Example 1, the phosphor mixture ratio of the phosphor portion 13 was set so that the color temperature range would be within a predetermined color temperature range when the blue LED chip 21 having a wavelength of 456 nm was used.

  In Example 2, the main wavelength (λd) of the blue LED chip 21 is 452 nm (minimum value) and 455 nm (maximum value), and the phosphor of the phosphor portion 13 is yellow phosphor. White LED devices 11 each having a correlated color temperature (Tc) of 5000 K and a color rendering property (Ra) of 70 are prepared using a phosphor coating solution in which a red phosphor is blended at a predetermined blending ratio. In Example 2, the fluorescence of the phosphor portion 13 is set so that the blue LED chip 21 has a wavelength of 455 nm, that is, a predetermined color temperature range when the blue LED chip 21 having the maximum dominant wavelength is used. The composition ratio of the phosphor is set, but when the blue LED chip 21 having the minimum dominant wavelength (452 nm in this case) is used, the composition ratio of the phosphor of the phosphor portion 13 is set so that the predetermined color temperature range is obtained. May be.

  Further, in Example 3, the main wavelength (λd) of the blue LED chip 21 is 452 nm (minimum value), 455 nm (median value), and 458 nm (maximum value), respectively. Is a white LED device 11 having a correlated color temperature (Tc) of 5000 K and a color rendering property (Ra) of 80 using a phosphor coating liquid in which a yellow phosphor, a green phosphor and a red phosphor are blended at a predetermined blending ratio. Are created. In Example 3, the blending ratio of the phosphors in the phosphor portion 13 was set so that a predetermined color temperature range was obtained when the blue LED chip 21 having a wavelength of 455 nm was used.

  Then, a colorimetric evaluation was performed on these Examples 1 to 3 using a fluorescence spectrophotometer (FP-6500, manufactured by JASCO Corporation). The results are shown in FIGS.

  As shown in these examples, when the phosphor portion 13 was configured using phosphor coating liquids blended at the same blending ratio, the color rendering was improved as the wavelength of the blue LED chip 21 was longer (FIG. 6). At this time, although the correlated color temperature slightly changes, it remains in a range where there is no sense of incongruity particularly in the use state. Specifically, when the correlated color temperature is 3200K, within ± 200K, when the correlated color temperature is 5000K, within ± 300K, and when the correlated color temperature is 6600K, within ± 500K, The white LED devices 11 are in a range in which there is no sense of incongruity, and the white LED devices 11 remain in such a change within the color temperature range, and can be used without any problem.

  As described above, in the above-described embodiment, the difference between the minimum main wavelength and the maximum main wavelength of the blue LED chip 21 is fixed in a state where the mixing ratio of the phosphors corresponding to the plurality of colors of the phosphor portion 13 is fixed. The color rendering properties are adjusted by selecting the dominant wavelength of the blue LED chip 21 to be within 10 nm. That is, in the above-described embodiment, a plurality of types of blue LED chips 21 having a dominant wavelength range of 10 nm or less are prepared, and a desired color rendering is achieved by selecting one of these blue LED chips 21 and using it. Get sex. For this reason, it is possible to finely adjust the color rendering properties within the range of about 5 points of the average color rendering index Ra without preparing specifications for the enormous phosphor blend ratio. As a result, in the conventional case using an enormous blending ratio specification of the phosphor, it is not easy to finely adjust the color rendering in a range of about 5 points of the average color rendering index Ra, and the blending ratio specification is complicated. Information management and maintenance are necessary, and there is a time loss due to the frequency of changing the phosphor coating liquid, whereas in the above embodiment, these are not necessary, and several types of main wavelengths are different from each other. Multiple types of white LED devices 11 having different color rendering properties can be efficiently manufactured simply by preparing the blue LED chip 21, so that both the color characteristics and the color rendering properties can be achieved while improving the productivity and reducing the cost. .

  Moreover, by selecting the blue LED chip 21 so that the main wavelength range is within 10 nm, the correlated color temperature of the white LED device 11 can be controlled within the desired color temperature range regardless of which blue LED chip 21 is used. .

  In addition, the blue LED chip 21 having a wavelength of 450 nm to 465 nm is not only excellent in characteristics but also significant in terms of its excitation characteristics when combined with, for example, a YAG-based phosphor. Can be obtained.

  Further, the mixing ratio of the phosphors in the phosphor portion 13 is set such that, among a plurality of types of blue LED chips 21 having a plurality of different main wavelengths, the blue LED chip 21 having the center value of the main wavelengths, in other words, By setting the blue LED chip 21 having the principal wavelength of the median wavelength range to have a predetermined color temperature range, the white LED device 11 using any of the plurality of types of blue LED chips 21 can also have a desired color temperature range. Only the color rendering property can be adjusted while keeping the color temperature range.

  In the above embodiment, the arrangement and the dominant wavelength of the blue LED chip 21 are not limited to the above configuration.

  The LED chip is not limited to the blue LED chip, and the color of the phosphor can be appropriately set in accordance with the emission color of the LED chip.

11 White LED device which is LED device
12 Board
13 Phosphor part
21 Blue LED chip as LED chip

Claims (2)

Manufacture of an LED device including an LED chip disposed on a substrate and a phosphor portion that covers a plurality of phosphors corresponding to a plurality of colors excited by light emission of the LED chip at a predetermined blending ratio. A method,
Color rendering properties are adjusted by selecting the main wavelength of the LED chip so that the difference between the minimum main wavelength and the maximum main wavelength of the LED chip is within 10 nm with the phosphor compounding ratio of the phosphor part fixed. A method for manufacturing an LED device. The compounding ratio of the phosphors is set so as to be within a predetermined color temperature range with respect to the LED chip having a central wavelength among a plurality of types of LED chips having a plurality of different main wavelengths. The manufacturing method of the LED device of Claim 1.

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