KR101692404B1 - Semiconductor light emitting device for uv curing - Google Patents

Abstract

The present disclosure relates to a semiconductor light emitting device for ultraviolet curing. The semiconductor light emitting device comprises a semiconductor light emitting device chip which includes an active layer, and emits light including ultraviolet light in the active layer; and an encapsulant which covers at least a part of the semiconductor light emitting device chip, and includes a wavelength conversion material that emits light having a peak wavelength different from light emitted from the semiconductor light emitting device chip in response to light emitted from the semiconductor light emitting device chip. At least 50% of light emitted from the semiconductor light emitting device chip is used for ultraviolet curing. So, the loss of a ultraviolet ray can be minimized.

Description

TECHNICAL FIELD [0001] The present invention relates to a semiconductor light emitting device for ultraviolet curing,

The present disclosure relates to a semiconductor light emitting device used for ultraviolet curing as a whole, and more particularly to a semiconductor light emitting device used for ultraviolet curing which emits various colors while maintaining ultraviolet curing performance.

Herein, the background art relating to the present disclosure is provided, and these are not necessarily meant to be known arts.

1 is a view showing an example of a conventional semiconductor light emitting device chip.

The semiconductor light emitting device chip includes a buffer layer 20, a first semiconductor layer 30 (e.g., an n-type GaN layer) 30 having a first conductivity, An active layer 40 (e.g., INGaN / (In) GaN MQWs) that generates light through recombination of holes, and a second semiconductor layer 50 (e.g., a p-type GaN layer) having a second conductivity different from the first conductivity A light transmitting conductive film 60 for current diffusion and an electrode 70 serving as a bonding pad are formed on the first semiconductor layer 30 and the first semiconductor layer 30 is etched to serve as a bonding pad Electrode 80 (e.g., a Cr / Ni / Au laminated metal pad) is formed. The semiconductor light emitting device of the type shown in FIG. 1 is called a lateral chip in particular. Here, when the growth substrate 10 side is electrically connected to the outside, it becomes a mounting surface.

2 is a view showing another example of the semiconductor light-emitting device chip disclosed in U.S. Patent No. 7,262,436. For ease of explanation, the drawing symbols have been changed.

The semiconductor light emitting device chip includes a growth substrate 10, a growth substrate 10, a first semiconductor layer 30 having a first conductivity, an active layer 40 for generating light through recombination of electrons and holes, And a second semiconductor layer 50 having a second conductivity different from that of the second semiconductor layer 50 are deposited in this order on the substrate 10, and three layers of electrode films 90, 91, and 92 for reflecting light toward the growth substrate 10 are formed have. The first electrode film 90 may be an Ag reflective film, the second electrode film 91 may be an Ni diffusion prevention film, and the third electrode film 92 may be an Au bonding layer. An electrode 80 functioning as a bonding pad is formed on the first semiconductor layer 30 exposed by etching. Here, when the electrode film 92 side is electrically connected to the outside, it becomes a mounting surface. The semiconductor light emitting device chip of the type shown in FIG. 2 is called a flip chip. In the case of the flip chip shown in FIG. 2, the electrodes 80 formed on the first semiconductor layer 30 are lower in height than the electrode films 90, 91, and 92 formed on the second semiconductor layer, . Here, the height reference may be a height from the growth substrate 10.

3 is a view showing an example of a conventional semiconductor light emitting device.

The semiconductor light emitting device 100 is provided with lead frames 110 and 120, a base 130, and a vertical type light emitting chip 150 in the cavity 140, Is filled with an encapsulant 170 containing the wavelength conversion material 160. The lower surface of the vertical type semiconductor light emitting device chip 150 is electrically connected directly to the lead frame 110 and the upper surface thereof is electrically connected to the lead frame 120 by the wire 180. A part of the light emitted from the vertical type semiconductor light emitting device chip 150 excites the wavelength conversion material 160 to produce light of a different color, and two different lights may be mixed to form white light. For example, the semiconductor light emitting device chip 150 generates blue light, and the light generated by exciting the wavelength conversion material 160 is yellow light, and blue light and yellow light may be mixed to form white light. FIG. 3 shows a semiconductor light emitting device using the vertical semiconductor light emitting device chip 150, but it is also possible to manufacture the semiconductor light emitting device of FIG. 3 using the semiconductor light emitting device chip shown in FIGS. 1 and 2 have. In recent years, the size of the semiconductor light emitting device tends to be miniaturized. Accordingly, a chip size package (CSP) has been developed more actively than a semiconductor light emitting device having the shape shown in FIG. For example, Japanese Laid-Open Patent Publication No. 2014-179586 shows an example of CSP.

 4 is a view showing an example of an ultraviolet curing apparatus disclosed in U.S. Patent Publication No. 2013-0313445.

The curing device is cured by ultraviolet light by turning on an ultraviolet light source (for example, an ultraviolet lamp or an ultraviolet light emitting device) inside a box-shaped housing, and then placing a nail with an ultraviolet curing material inside the housing. Exposure to ultraviolet rays for a long time may have a detrimental effect on the human body, so it is preferable to appropriately adjust the curing time using a timer. In the case of ultraviolet rays, the visibility is so low that the light perceived by the user is not the ultraviolet rays involved in curing but the light in the visible light region emitting in a wavelength region longer than ultraviolet rays. However, since the light in the visible light region emitted from the semiconductor light emitting device used in the conventional ultraviolet curing is not intended, it is caused by crystal defects or structural defects of the semiconductor light emitting device chip used in the semiconductor light emitting device, The color tone of the light in the visible light region is not constant. In addition, the light in the visible light region generated by crystal defects or structural defects is mainly bluish purple or yellow or a mixed color thereof, which causes the user to feel discomfort.

The present disclosure provides a semiconductor light emitting device for ultraviolet curing that minimizes the manufacturing cost of a semiconductor light emitting device used in a conventional ultraviolet curing apparatus and provides a uniform color to a user and further minimizes loss of ultraviolet rays for curing.

This will be described later in the Specification for Enforcement of the Invention.

SUMMARY OF THE INVENTION Herein, a general summary of the present disclosure is provided, which should not be construed as limiting the scope of the present disclosure. of its features).

According to one aspect of the present disclosure, there is provided a semiconductor light emitting device for ultraviolet curing, comprising: a semiconductor light emitting device chip including an active layer, wherein light emitted from the active layer A semiconductor light emitting device chip; An encapsulant covering at least a part of the semiconductor light-emitting device chip, the encapsulant including a wavelength conversion material that emits light of a color different from light emitted from the semiconductor light-emitting device chip in response to light emitted from the semiconductor light-emitting device chip; And more than 50% of the light emitted from the semiconductor light emitting device chip is used for ultraviolet curing. The present invention also provides a semiconductor light emitting device for ultraviolet curing.

This will be described later in the Specification for Enforcement of the Invention.

1 is a view showing an example of a conventional semiconductor light emitting device chip,
2 is a view showing another example of the semiconductor light-emitting device chip disclosed in U.S. Patent No. 7,262,436,
3 is a view showing an example of a conventional semiconductor light emitting device,
4 is a diagram showing an example of an ultraviolet curing apparatus disclosed in U.S. Patent Application Publication No. 2013-0313445,
5 is a view showing an example of a calculation formula for obtaining the loss of light emitted from the semiconductor light emitting device chip by the wavelength conversion material,
6 is a view showing an example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure;
7 is a view for explaining the reason why white light can be obtained while being suitable for ultraviolet curing in a semiconductor light emitting device for ultraviolet curing according to the present disclosure,
8 is a view showing another example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure,
9 is a view showing another example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure.

The present disclosure will now be described in detail with reference to the accompanying drawings.

5 is a diagram showing an example of a calculation formula for obtaining loss of light emitted from the semiconductor light emitting device chip by the wavelength conversion material.

5 (a), the color coordinates and brightness of the red light 200 are represented by (x ₁ , y ₁ ) and Y ₁ when the light of three colors of red 200, green 210 and blue 220 is mixed. The color coordinates and brightness of green 210 are represented by (x ₂ , y ₂ ) and Y ₂ , the color coordinates and brightness of blue 220 are represented by (x ₃ , y ₃ ), and Y ₃ , the result Y (230) color coordinates and brightness of the (x _t, y _t), Y if as _t, Figure 5 (b) the ratio of brightness of the three colors in accordance with the calculation, such as the _{1: Y 2: Y 3 (} = 1) can be obtained. The ratio of each light from the brightness ratio of the three colors can be converted using the visibility curve. The ratio of light of three colors is P ₁ : P ₂ : P ₃ And the ratio of the light emission (P ₁ + P ₂ ) by the wavelength converting material for obtaining Y ₁ : Y ₂ : Y ₃ is defined as?, And the loss of light due to the wavelength conversion material (Po Loss) is? ',?' Can be obtained through the calculation formula of FIG. 5 (c). 5 (d) is a view showing the relationship between P ₁ , P ₂ and P ₃ and P ' ₁ , P' ₂ and P ' ₃ .

6 is a view showing an example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure.

The semiconductor light emitting device 300 for ultraviolet curing includes a semiconductor light emitting device chip 310 including the active layer 311 and an encapsulant 320 covering at least a part of the semiconductor light emitting device chip 310. The semiconductor light emitting device chip 310 may be one of a flip chip, a lateral chip, and a vertical chip. 6 is a cross-sectional view of the flip chip. In addition, although a CSP type semiconductor light emitting device is shown, a package type semiconductor light emitting device as shown in FIG. 3 is also possible. The semiconductor light emitting device chip 310 includes an electrode 312. The active layer 311 emits light including ultraviolet rays. For example, the semiconductor light emitting device chip 310 may emit ultraviolet light having a wavelength range of 380 nm to 410 nm. And preferably emits ultraviolet light having a wavelength of 385 nm. The reason why ultraviolet rays of 385 nm wavelength is preferable is explained in Fig. The encapsulant 320 includes a wavelength conversion material 321 that emits light of a different color from light emitted from the semiconductor light emitting device chip in response to light emitted from the semiconductor light emitting device chip 310. The types and characteristics of the wavelength conversion material 321 will be described with reference to FIGS. 7 to 8. FIG. However, the loss of light emitted from the semiconductor light emitting device chip 310 by the wavelength converting material 321 is preferably 20% or less. When the loss of light is 20% or more, the efficiency of ultraviolet curing is deteriorated, which is not preferable. That is, it is preferable that 80% or more of ultraviolet rays for curing emitted from the semiconductor light emitting device chip 310 does not react with the wavelength converting material 321. Experimentally, it is preferable that at least 50% of ultraviolet rays for curing from the semiconductor light emitting device chip 320 do not react with the wavelength converting material 321 for ultraviolet curing. FIG. 6 (b) shows various positions of the sealing material 220.

7 is a view for explaining the reason why white light can be obtained in a state where loss of ultraviolet rays for ultraviolet curing is small in a semiconductor light emitting device for ultraviolet curing according to the present disclosure.

7 (a) shows a characteristic of a semiconductor light emitting device using a yellow wavelength conversion material which emits yellow light in response to light emitted from a semiconductor light emitting device chip and a semiconductor light emitting device chip which emits ultraviolet rays of 400 nm wavelength. The color coordinates 400 of the 400 nm wavelength are (0.178, 0.051), and the color coordinates of the semiconductor light emitting device change from # 1 410 to # 10 (411) on the chromaticity coordinates according to the amount of use of the yellow wavelength conversion material. The yellow wavelength conversion material emits light having an emission spectrum as shown in FIG. 7 (b) in response to light emitted from the semiconductor light emitting device chip. That is, both ends 421 and 422 having a peak wavelength 420 of 565 nm and a relative intensity of 60% have wavelengths of 515 nm and 610 nm, respectively. The color coordinates of the 515 nm wavelength 421 at both ends are (0.66576, 0.33401) and the color coordinates of the 610 nm wavelength 422 are (0.03885, 0.81202). That is, red light and green light. The white light can be obtained by mixing the three colors of red and green light emitted from the blue and yellow wavelength conversion material from the semiconductor light emitting device chip. In order to obtain the case where the color coordinates of the light emitted from the semiconductor light emitting device is (0.275, 0.2450), the brightness emitted from the semiconductor light emitting device chip is Y3, the brightness of the green light emitted by the wavelength converting material is Y1, and the brightness of red light emitted by the wavelength converting material Y2, a light loss (Po_Loss) due to the wavelength conversion material can be obtained according to the equation described in Fig. The following table is simulation data showing the light loss according to the color coordinates of the light emitted from the semiconductor light emitting device. 7 (c) is a graph showing [Table 1].

number z x y Po Loss (%) #One 0.387 0.306 0.3070 20.5 #2 0.48 0.275 0.2450 13.6 # 3 0.564 0.247 0.1890 8.7 #4 0.57 0.245 0.1850 8.4 # 5 0.582 0.241 0.1770 7.8 # 6 0.712 0.198 0.0900 2.1 # 7 0.732 0.191 0.0770 1.4 #8 0.747 0.186 0.0670 0.83 # 9 0.75 0.185 0.0650 0.72 # 10 0.768 0.179 0.0530 0.10

And light loss of about 20.5% occurs in # 1 (410). This corresponds to white on the color coordinate system. That is, the semiconductor light emitting device emits white light instead of 20.5% loss of light having a wavelength of 400 nm used for ultraviolet curing. 7D is a graph showing simulation data 430, experimental data 431 and loss of light 432 of the wavelength conversion material CR (Conversion Rate) with respect to the color coordinate z of the semiconductor light emitting device . In the region of # 1 410 where the semiconductor light emitting device emits white light, the loss of light due to the wavelength conversion material is larger than CR but the z coordinate is lower, that is, the closer to the color coordinate of the light emitted from the semiconductor light emitting device chip, They have almost similar values. This is because if the amount of the wavelength conversion material increases, the loss of light due to the conversion of the wavelength conversion material increases, and if the amount of the wavelength conversion material is small, most of the light emitted from the semiconductor light emitting device chip passes through without passing through the wavelength conversion material. 7E shows that the chromaticity coordinate z and the color purity 440 of the semiconductor light emitting device are linearly proportional to each other while the CR 441 is inversely proportional to the color purity 440. Even when the color purity was 60% or less, it was confirmed that the semiconductor light emitting element was sufficiently exposed to white light. Further, even when the color purity of the white light is 50% or less, there is no difference from using the conventional semiconductor light emitting element that emits white light. 7 (c) to 7 (e), even when about 80% of the light emitted from the semiconductor light emitting device chip is used for curing, the remaining about 20% of the light reacts with the wavelength converting material, . FIG. 7 (f) shows the relationship between the conversion ratio and the color purity of the wavelength converting material according to the wavelength of light emitted from the semiconductor light emitting device chip. The semiconductor light-emitting device chip 450 that emits light having a wavelength of 385 nm can obtain high color purity even at a low conversion rate. It is preferable to use a semiconductor light emitting device chip which emits ultraviolet rays of a low wavelength to obtain the same level of color purity since the loss of light is small as the conversion rate of the wavelength conversion material is low. When a semiconductor light emitting device chip that emits ultraviolet rays having a wavelength of 385 nm is used, a semiconductor light emitting device chip that emits ultraviolet light having a wavelength of 400 nm even if the color purity of the white light emitted by the semiconductor light emitting device is 10% to 40% It is preferable that the color purity is 10% to 40%, considering visibility and light loss.

8 is a view showing another example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure.

Although a semiconductor light emitting element used in an ultraviolet curing apparatus has an advantage of enhancing the visibility of a user when white light is emitted, it is insufficient for the user to feel aesthetically pleasing. When the semiconductor light emitting element used in the ultraviolet curing apparatus emits colored light such as blue cyan or green system green or pink based color, the ultraviolet curing apparatus used for cosmetics has a high It will give you a good feeling. 8 (a), when a green wavelength conversion material that emits green light having a peak wavelength of (0.178, 0.575) in response to light emitted from the semiconductor light emitting device chip is used, ultraviolet curing A semiconductor light emitting element for ultraviolet curing with high color purity can be obtained. In this case, however, ultraviolet rays not converted by the wavelength conversion material should be at least 50%. 8 (b) shows the relationship between the optical loss 510 of the ultraviolet light by the wavelength converting material and the chromaticity coordinate z of the semiconductor light emitting element, and the CR 511. 8 (c) shows that the semiconductor light emitting device emits light along the dotted line 520 when a red wavelength conversion material that emits red light in response to light emitted from the semiconductor light emitting device chip is used in the color coordinate system. Further, And the relationship between the CR 531 and the chromaticity coordinate z of the semiconductor light emitting device. In order to obtain white light as the wavelength converting material used in Figs. 7 to 8, it is preferable to use a material having a broad emission spectrum like the yellow wavelength conversion material described in Fig. 7, but it is preferable to use a material having a high color purity such as red or green It is preferable to use one having a narrow emission spectrum. For example, it is preferable to use a quantum dot wavelength conversion material having an emission spectrum of 30 nm or less. As the wavelength converting material, there are YAG (Garmet) phosphor, silicate phosphor, nitride phosphor and LuAG phosphor. YAG phosphors have the best conversion efficiency and wide emission spectrum. They are most widely used for making white LEDs with blue LEDs. Nitride phosphors are effective for emitting red light, and phosphor phosphors are effective for effective coloring when ultraviolet rays are used as a light source. Is substantially the same as the semiconductor light emitting element described in Fig. 6, except for that described in Fig.

9 is a view showing another example of a semiconductor light emitting device for ultraviolet curing according to the present disclosure.

In the ultraviolet curing apparatus, blue violet light can be used for enhancing the visibility of the user. However, the blue-violet light emitted from the semiconductor light emitting device used in the conventional ultraviolet curing apparatus is not intended, and therefore, there is a problem in that it is not uniform for each product. The active layer 600 of the semiconductor light-emitting device chip has a multi-quantum well (MQW) structure, thereby intentionally emitting light from purple to blue light. The active layer 600 is located between the first semiconductor layer 610 and the second semiconductor layer 520. The electrons 630 move from the first semiconductor layer 610 to the second semiconductor layer 620. The blue light emitting quantum well 601 is located on the first semiconductor layer 610 side and the ultraviolet light emitting quantum well 602 is located on the second semiconductor layer 620 side and the blue light emitting quantum well 601 and the ultraviolet light emitting quantum well 602 are located, The control barrier layer 603 is located between the barrier layers. Silicon (Si) is doped into the control barrier layer 603 so that electrons move well to the ultraviolet light quantum well 602 as the main emission and the holes are prevented from moving well in the blue light emitting quantum well 601 which is auxiliary light emission. Therefore, it is possible to control the amount of blue light and ultraviolet light by controlling the doping concentration of silicon (Si). It is preferable that 50% or more ultraviolet light is emitted for ultraviolet curing. Further, when the blue-violet light can give an uncomfortable feeling to the user, it is possible to emit various colors by using a wavelength conversion material of red, yellow, or green series. Is substantially the same as the semiconductor light emitting element described in Fig. 6, except for that described in Fig.

Various embodiments of the present disclosure will be described below.

(1) A semiconductor light emitting device for ultraviolet curing, comprising: an active layer; a semiconductor light emitting device chip for emitting light including ultraviolet light in the active layer; An encapsulant covering at least a part of the semiconductor light-emitting device chip, the encapsulant including a wavelength conversion material that emits light of a color different from light emitted from the semiconductor light-emitting device chip in response to light emitted from the semiconductor light-emitting device chip; Wherein at least 50% of light emitted from the semiconductor light emitting device chip is used for ultraviolet curing.

(2) A semiconductor light emitting device for ultraviolet curing, characterized in that the semiconductor light emitting device for ultraviolet curing emits white light.

(3) The semiconductor light-emitting device for ultraviolet curing, wherein the color purity of the white light is 50% or more and 60% or less.

(4) A semiconductor light emitting device for ultraviolet curing, characterized in that the semiconductor light emitting device for ultraviolet curing emits colored light.

(5) The semiconductor light-emitting device for ultraviolet curing, wherein the semiconductor light-emitting device chip emits light in a wavelength range of 380 nm to 410 nm.

(6) The semiconductor light-emitting device chip emits light with a wavelength of 385 nm, the semiconductor light-emitting device for ultraviolet curing emits white light, and the color purity of the white light is 10% or more and 40% or less. .

(7) The semiconductor light emitting device for ultraviolet curing according to (7), wherein the wavelength conversion material is at least one of a yellow wavelength conversion material, a green wavelength conversion material and a red wavelength conversion material.

(8) The semiconductor light emitting device for ultraviolet curing, wherein the wavelength conversion material is a quantum dot wavelength conversion material.

(9) The semiconductor light emitting device chip is a blue light emitting quantum well; Ultraviolet light emitting quantum well; And a control barrier layer positioned between the blue light emitting quantum well and the ultraviolet light emitting quantum well.

(10) The semiconductor light emitting device for ultraviolet curing as set forth in claim 1, wherein the control barrier layer controls the number of holes passing through the control barrier layer through the silicon (Si) doping concentration.

According to the semiconductor light emitting device of the present disclosure, in the ultraviolet curing apparatus for beauty used in curing such as nails, a manufacturing cost is minimized, while a uniform color is provided to the user to increase the likelihood, and further, the loss of ultraviolet rays for curing is minimized A semiconductor light emitting element for ultraviolet curing can be obtained.

Semiconductor light-emitting device chip: 150, 310
Semiconductor light emitting device: 100, 300

Claims (10)

A semiconductor light emitting device for ultraviolet curing,
A semiconductor light emitting device chip comprising an active layer, comprising: a semiconductor light emitting device chip for emitting light including ultraviolet light in an active layer; And,
An encapsulant covering at least a part of the semiconductor light emitting device chip, wherein the encapsulant comprises a wavelength conversion material which emits light having a peak wavelength different from light emitted from the semiconductor light emitting device chip in response to light emitted from the semiconductor light emitting device chip ≪ / RTI >
50% or more of the ultraviolet rays emitted from the semiconductor light-emitting device chip are used for ultraviolet curing through the encapsulant without reacting with the wavelength converting material,
Wherein the semiconductor light emitting element for ultraviolet curing emits white light from a wavelength converting material that emits light having another peak wavelength. delete The method according to claim 1,
Wherein the color purity of the white light is 50% or more and 60% or less. delete The method according to claim 1,
Wherein the semiconductor light emitting device chip emits light in a wavelength range of 380 nm or more and 410 nm or less. The method of claim 5,
The semiconductor light emitting device chip emits light having a wavelength of 385 nm,
Wherein the semiconductor light emitting element for ultraviolet curing emits white light and the color purity of the white light is 10% or more and 40% or less. The method according to claim 1,
And the wavelength conversion material is a yellow wavelength conversion material. delete A semiconductor light emitting device for ultraviolet curing,
A semiconductor light emitting device chip comprising an active layer, comprising: a semiconductor light emitting device chip for emitting light including ultraviolet light in an active layer; And,
An encapsulant covering at least a part of the semiconductor light emitting device chip and including a wavelength converting material which emits light of a color different from light emitted from the semiconductor light emitting device chip in response to light emitted from the semiconductor light emitting device chip In addition,
50% or more of the ultraviolet rays emitted from the semiconductor light-emitting device chip are used for ultraviolet curing through the encapsulant without reacting with the wavelength converting material,
The semiconductor light-
Blue light emitting quantum well;
Ultraviolet light emitting quantum well; And,
And a control barrier layer positioned between the blue light emitting quantum well and the ultraviolet light emitting quantum well. The method of claim 9,
Wherein the controllable barrier layer controls the number of holes passing through the control barrier layer through the silicon (Si) doping concentration.

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