KR101310107B1 - Encapsulant For UVLED Device, UVLED Device Using The Same And Manufacturing Method thereof - Google Patents

Abstract

The present invention forms an encapsulation portion that protects an ultraviolet light emitting diode (UVLED) chip having excellent heat resistance and chemical resistance, and can suppress the yellowing of the encapsulation portion caused by ultraviolet light generated when driving the UVLED chip, and the UV transmittance is a UVLED device. It is for providing the sealing material for sealing, a UVLED element using the same, and its manufacturing method. The UVLED device according to the present invention includes a mounting substrate, a UVLED chip mounted on the mounting substrate, and an encapsulant of polysilazane material covering the UVLED chip on the mounting substrate. The polysilazane is a polymer type and consists of a polymer in which nitrogen and silicon atoms are exclusively crossed. Polysilazane is an inorganic encapsulant having excellent heat resistance and chemical resistance because it is easily changed into silica component even at a heat treatment (curing) of 200 degrees or less or even at room temperature, and exhibits excellent ultraviolet transmittance as compared to glass.

Description

Encapsulant for 소자 LED device, ＵＶLED device using same and manufacturing method thereof {Encapsulant For UVLED Device, UVLED Device Using The Same And Manufacturing Method

The present invention relates to a light emitting device and a method for manufacturing the same, and more particularly, to form an encapsulation portion for protecting an ultraviolet light emitting diode (UVLED) chip having excellent heat resistance and chemical resistance, and encapsulated by ultraviolet light generated by driving of the UVLED chip. The present invention relates to an encapsulant for a UVLED device containing polysilazane that can suppress negative yellow change and excellent UV transmittance, a UVLED device using the same, and a manufacturing method thereof.

Background Art In recent years, light emitting diode (LED) elements that emit white light have been put to practical use, and have been used for applications such as backlighting of lighting equipment and liquid crystal displays.

In general, a white LED element contains a blue LED chip, which is a group III nitride compound semiconductor that irradiates blue light, and a powder of a yellow phosphor that converts the light emitted from the LED chip into yellow light using excitation light as an excitation light. LED chips are packaged and manufactured by transparent resins such as epoxy or silicone. In addition, in order to obtain color rendering from a white LED device, a white LED device has been proposed in which a green phosphor or a red phosphor powder is added to a transparent resin and a LED chip is packaged.

However, in the conventional white LED device, since the transparent resin is used as an encapsulant, the transparent resin in the region adjacent to the LED chip changes according to the light emitted from the LED chip, heat, or the like, and the light irradiation efficiency is gradually decreased. . In particular, in the case of using a short-wavelength LED chip that irradiates blue light, ultraviolet light, or the like with high energy, deformation such as yellow change of the transparent resin tends to be remarkable.

In addition, since the transparent resin has gas permeability, the powder of the phosphor contained in the transparent resin reacts with the gas in the air in many cases, and the fluorescence property is gradually decreased. The deterioration of these properties is prone to hydrolysis and is remarkable in emulsion phosphors, aluminate phosphors, and silicate phosphors which are poor in moisture resistance.

Such packaging with a transparent resin is difficult to sufficiently satisfy the characteristics of heat resistance, light resistance and gas permeability required for the LED element. In order to solve the problems caused by the above-mentioned transparent resin, a glass packaging LED device for packaging an LED chip using glass having heat resistance, light resistance, and gas permeability not present in the transparent resin has been proposed.

However, since the glass is melted at a high temperature of 500 degrees or more, when encapsulating the UVLED chip with a glass encapsulant, the UVLED chip may be damaged or the mounting substrate on which the UVLED chip is mounted may be deformed during the encapsulation process. This may cause a problem that the characteristics of the manufactured UVLED device is inferior. In addition, as shown in FIGS. 5 and 6, the glass also has a problem in that transmittance of ultraviolet rays of 300 nm or less is not good.

Accordingly, an object of the present invention is to solve the above-mentioned problem, and forms an encapsulation portion for protecting an ultraviolet light emitting diode (UVLED) chip having excellent heat resistance and chemical resistance, and the sulfur encapsulation portion of the encapsulation portion caused by ultraviolet rays generated by driving the UVLED chip. It is providing the sealing material for UVLED elements which can suppress a change and is excellent in UV transmittance, a UVLED element using the same, and its manufacturing method.

The present invention for achieving the object as described above provides an encapsulant for a UVLED device comprising a polysilazane (Polysilazane) of a polymer type composed of a polymer exclusively crossed nitrogen and silicon atoms. Such polysilazane is an inorganic encapsulant having excellent heat resistance and chemical resistance because it is easily changed into a silica component even at a heat treatment of 200 degrees or less or even at room temperature.

The present invention also provides a UVLED device including a mounting substrate, a UVLED chip mounted on the mounting substrate, and an encapsulant of polysilazane material covering the UVLED chip on the mounting substrate.

In the UVLED device according to the present invention, the encapsulation portion may be coated with a liquid polysilazane on the mounting substrate to cover the UVLED chip.

In the UVLED device according to the present invention, the encapsulation portion is formed on the mounting substrate surrounding the UVLED chip, the support is formed on the upper portion is exposed to expose the UVLED chip, and installed to cover the opening of the support the UVLED It may include a lens of polysilazane material covering the chip.

The present invention also includes preparing a mounting substrate, mounting a UVLED chip on the mounting substrate, and applying a sealing material of polysilazane (Polysilazane) material on the mounting substrate to cover the UVLED device. It provides a method of manufacturing a UVLED device comprising a sealing step of forming an encapsulation.

And in the method of manufacturing a UVLED device according to the present invention, the encapsulation step is a step of applying a sealing material of a liquid polysilazane (Polysilazane) material to cover the UVLED device on the mounting substrate, and the applied encapsulant It may include the step of forming the encapsulation by curing at room temperature to 200 degrees.

According to the present invention, since the encapsulant for the UVLED device includes polysilazane, when encapsulating the UVLED chip with a liquid encapsulant, the UVLED chip may be encapsulated by heat treatment at room temperature or 200 degrees or less. In addition, the encapsulation portion formed of an encapsulant including polysilazane exhibits excellent heat resistance and chemical resistance characteristics. In addition, the encapsulation portion formed of the encapsulant including polysilazane suppresses the yellow change of the encapsulation portion caused by ultraviolet rays generated when the UVLED chip is driven. In addition, since the encapsulation portion formed of the encapsulant including polysilazane exhibits excellent ultraviolet transmittance as compared with glass, the encapsulant including polysilazane exhibits suitable properties as a encapsulant for UVLED devices.

1 is a cross-sectional view of a UVLED device according to a first embodiment of the present invention.
FIG. 2 is an enlarged view of portion “A” of FIG. 1.
3 is a flowchart illustrating a method of manufacturing a UVLED device according to a first embodiment of the present invention.
4 is a graph showing the light transmittance of the polysilazane plate formed of the encapsulant forming the encapsulation.
5 is a graph showing ultraviolet and visible light transmittance of a 0.7 mm thick soda-lime glass substrate.
6 is a graph showing ultraviolet and visible light transmittance of a 0.7 mm thick LCD glass substrate.
7 is a cross-sectional view of a UVLED device according to a second embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the embodiment of the present invention will be described, and the description of other parts will be omitted so as not to disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be water and variations.

1 is a cross-sectional view of a UVLED device according to a first embodiment of the present invention. FIG. 2 is an enlarged view of portion “A” of FIG. 1.

1 and 2, the UVLED device 100 according to the first embodiment includes a mounting substrate 30, a UVLED chip 10, and an encapsulation unit 60. Here, the encapsulation unit 60 may be formed as an encapsulant for the UVLED device 100 of the present invention described below.

In the UVLED device 100 according to the first embodiment, after the at least one UVLED chip 10 is provided on the mounting substrate 30, the top of the UVLED chip 10 is encapsulated with a liquid polysilazane material. The encapsulation part 60 is covered with ash and cured in a predetermined manner. Accordingly, ultraviolet rays generated from the UVLED chip 10 by the power supplied to the UVLED chip 10 are emitted to the outside through the encapsulation unit 60.

Here, the encapsulation part 60 according to the first embodiment contains polysilazane that can be cured even at a low temperature. Polysilazane is excellent in adhesion to the mounting substrate 30 during curing, there is no separate crack in the curing process and supports to form a thicker encapsulation (60). The encapsulant containing the liquid polysilazane can be applied to a predetermined thickness on the mounting substrate 30 on which the UVLED chip 10 is formed, and can be cured at room temperature when the temperature is around 200 degrees or during the catalyst treatment. do. Therefore, the encapsulant for the UVLED device 100 forming the encapsulation 60 does not require a separate high temperature environment for the mounting substrate 30 or the UVLED chip 10 to form the encapsulation 60, and thus, the encapsulation substrate 60. The sealing portion 60 can be stably formed with little thermal stress to the 30 or the UVLED chip 10.

Each of the components of the UVLED device 100 according to the first embodiment will be described in detail as follows.

The mounting substrate 30 may include a poly resin (PP) substrate, an epoxy resin substrate, a composite base material substrate, a flexible or flexible base material substrate, a ceramic base material substrate, and a metal. (Metal Cored Base Material) substrate and the like can be used. For example, the mounting substrate 30 may be made of a ceramic substrate such as alumina (Al ₂ O ₃ ). The thermal expansion rate of the alumina forming the mounting substrate 30 is about 7 × 10 ⁻⁶ / ° C., and the thermal expansion rate of the mounting substrate 30 is preferably similar to that of the UVLED chip 10. Do. A wiring 40 for supplying power to the UVLED chip 10 may be formed on the mounting substrate 30. The wiring 40 is electrically connected to the bumps 50 of the UVLED chip 10 and is formed on the front surface of the mounting board 30, and formed on the rear surface of the mounting board 30. The back wiring 42 which can be connected, and the joint wiring 43 which connects the front wiring 41 and the back wiring 42 can be included. The front wiring 41, the back wiring 42 and the joint wiring 43 are tungsten (W) / nickel (Ni) / pattern formed in a pattern according to the electrode shape of the UVLED chip 10. It may be formed of a material such as gold (Au). In the wiring structure as described above, since the front wiring 41 is drawn out to the joint wiring 43 as the back wiring 42, the sealing material for the UVLED element 100 for forming the sealing portion 60 flows into an unnecessary place. Or to simplify the manufacturing process without fear of covering the electrical terminals. Since the mounting substrate 30 supports encapsulation processing of the plurality of UVLED chips 10 in a batch, mass production of the plurality of UVLED elements 100 may be facilitated. In addition, the mounting substrate 30 is formed of a material having a thermal expansion rate similar to that of the encapsulation unit 60, thereby ensuring a firm bonding state between the mounting substrate 30 and the encapsulation unit 60 according to appropriate chemical bonding when the encapsulation unit 60 is formed. It can support and prevent the delamination due to the weakening of the adhesive even in a small space. In addition, by using a substrate having the same thermal expansion coefficients of the UVLED chip 10 and the encapsulation portion 60 as the mounting substrate 30, it is possible to reduce internal stress caused by temperature difference and to suppress crack generation. In addition, when the mounting substrate 30 is formed of alumina or the like, excellent thermal conductivity, large light quantity, high output, and the like can be achieved.

Meanwhile, the mounting substrate 30 may be processed to have a small light absorption to provide an optical effect improvement. In the structure of the mounting board 30, the wirings are formed on the front and rear surfaces of the mounting board 30, respectively, and the structures are connected to the wirings, but the present invention is not limited thereto. For example, the mounting board 30 may have a wire connected to the UVLED chip 10 on the front surface of the mounting board 30, and may be connected to an external power supply on the front surface of the mounting board 30. Such structural changes to the wiring may be adjusted by the designer's option.

The UVLED chip 10 is formed of a gallium nitride compound semiconductor (Al _{1 -X- Y} In _X Ga _Y N, 0≤X≤1,0≤Y≤1,0≤X + Y) on the surface of the crystal growth substrate. A buffer layer, an n-type layer, a light emitting layer, and a p-type layer formed of ≤1) may be sequentially stacked by a metal organic vapor phase growth method (MOVPE method). Since the UVLED chip 10 is grown in a high temperature environment, the heat resistant temperature is excellent. As the electrode of the UVLED chip 10, a p-side electrode provided at almost the entire surface of the p-type layer and a p-side pad electrode provided at a portion of the p-side electrode may be provided, and a predetermined region is n from the p-type layer. Dry etching may be performed to the mold layer to expose the n-type electrode in the n-type layer on the bottom thereof. The p-side pad electrode and the n-side electrode may be connected to the bump 50, respectively. The bumps 50 may be connected to the front wires 41 of the mounting board 30, respectively, to provide the UVLED chip 10 with power provided through the wires 40.

In the above description, the UVLED chip 10 using the gallium nitride compound semiconductor as the UVLED chip 10 has been described, but the present invention is not limited thereto. For example, the UVLED chip 10 may include a UVLED chip 10 made of another semiconductor material such as, for example, zinc selenide (ZnSe).

The encapsulation unit 60 is formed to cover the UVLED chip 10 and the mounting substrate 30 after the UVLED chips 10 are formed on the mounting substrate 30. At this time, the encapsulation unit 60 is an encapsulant provided with a liquid polysilazane, and may be evenly applied to the mounting substrate 30 and the UVLED chip 10, and supports curing at a low temperature after application.

Polysilazane is a polymer composed of a polymer in which nitrogen and silicon atoms are exclusively crossed within the main structure shown in the following formula (1).

Wherein R ¹ , R ² , R ³ may be hydrogen, an alkyl group or an aryl group.

As an example of such a polysilazane, there may be a perhydropolysilazane such as the following Chemical Formula 2.

As described above, the encapsulant for the UVLED device 100 according to the first embodiment encapsulates the UVLED chip 10 with liquid polysilazane. Accordingly, the encapsulant for the UVLED device 100 according to the first embodiment supports the firm coupling between the encapsulation unit 60 and the mounting substrate 30 to be formed and encapsulates the enclosed UVLED chip 10 in a low temperature environment. The UVLED chip 10 may not provide an unnecessary high temperature environment and thus may support the formation of the encapsulation unit 60 even at room temperature without a separate crack.

In the above, the encapsulant for the UVLED device 100 used in the UVLED device 100 and the UVLED device 100 according to the first embodiment has been described. Hereinafter, a method of manufacturing the UVLED device 100 according to the first embodiment will be described in more detail with reference to FIGS. 1 to 3. 3 is a flowchart illustrating a method of manufacturing the UVLED device 100 according to the first embodiment of the present invention.

The manufacturing method of the UVLED device 100 according to the first embodiment starts from step S110 for preparing the mounting substrate 30. At this time, the mounting substrate 30 is a structure in which the UVLED chip 10 is mounted and is formed of a material having a small light absorption force or a surface on which the UVLED chip 10 is mounted so that the light absorption force is small to improve the light efficiency of the UVLED chip 10. Surface treatment may be performed. In addition, the mounting substrate 30 may use a substrate made of a material having a similar or equivalent thermal expansion coefficient to the UVLED chip 10 and the encapsulation unit 60 formed in step S140. Since the mounting substrate 30 is made of the above-described material, it is possible to suppress the occurrence of cracks due to thermal expansion.

Next, the UVLED chip 10 is mounted on the mounting board 30 in step S120, and the wiring 40 is connected. Substantially, the mounting substrate 30 provided in step S110 has a form in which the wiring 40 is already formed. That is, the mounting board 30 may be prepared in a form in which a front wiring 41, a back wiring 42, and a joint wiring 43 connecting the front wiring 41 and the back wiring 42 are formed. After the mounting substrate 30 is provided, the UVLED chip 10 is mounted by flip chip bonding so that the bump 50 of the UVLED chip 10 is electrically connected to the front wiring 41. Accordingly, when power is supplied through the back wiring 42, the power may be transmitted to the UVLED chip 10 through the joint wiring 43, the front wiring 41, and the bump 50.

Meanwhile, an example in which the UVLED chip 10 is mounted by flip chip bonding in step S210 is disclosed, but is not limited thereto. After the UVLED chip 10 is attached to the mounting substrate 30, the UVLED chip 10 may be electrically connected to the mounting substrate 30 through a metal wire of gold (Au) or aluminum (Al).

Next, the liquid encapsulant is coated on the mounting substrate 30 to cover the UVLED chip 10 in step S130. In this case, the liquid encapsulant forms the encapsulation part 60 through a curing process, and the encapsulant includes polysilazane.

In operation S140, the encapsulant is cured to form the encapsulation part 60, thereby manufacturing the UVLED device 100 according to the first embodiment. At this time, the temperature environment for forming the encapsulation unit 60 may be a temperature around 200 degrees. In particular, the encapsulation portion 60 may be formed at room temperature during the catalyst treatment. That is, the curing of the encapsulant may be performed at a low temperature of room temperature to 200 degrees.

As described above, the manufacturing method of the UVLED device 100 according to the first embodiment of the present invention encapsulates the UVLED chip 10 by using an encapsulant containing a liquid polysilazane, and the encapsulation part 60. At the time of forming, by curing in a low temperature environment of room temperature or 200 degrees or less, it supports the manufacture of a stable UVLED device 100.

As described above, the reason for using the encapsulant including polysilazane as the encapsulant is as follows. The encapsulant including polysilazane can be encapsulated by heat-treating the UVLED chip 10 at room temperature or 200 degrees or less, and has excellent heat resistance and can suppress sulfur change of the encapsulant. That is, polysilazane can be easily converted into silica component even at heat treatment below 200 degrees or even at room temperature, and thus can be used as an inorganic encapsulant having excellent heat resistance and chemical resistance.

In addition, since the encapsulant including polysilazane has excellent UV transmittance as compared to glass, as shown in Table 1 below and FIGS. 4 to 6, it is confirmed that the encapsulant exhibits suitable properties as an encapsulant for the UVLED device 100. Can be. 4 is a graph showing the light transmittance of the polysilazane plate formed of the encapsulant forming the encapsulation. 5 is a graph showing ultraviolet and visible light transmittance of a 0.7 mm thick soda-lime glass substrate. 6 is a graph showing ultraviolet and visible light transmittance of a 0.7 mm thick LCD glass substrate. In Figure 4 is a graph showing the ultraviolet and visible light transmittance of the 0.3mm thickness polysilazane plate. (Why should I mention thickness here?)

4 to 6, ultraviolet and visible light of a 0.3 mm thick polysilazane plate, a 0.7 mm thick soda-lime glass substrate, and a 0.7 mm thick LCD glass substrate formed using the encapsulant according to the first embodiment. The transmittance was measured.

As a result of the UV transmittance measurement, it was confirmed that the polysilazane plate formed of the encapsulant according to the first embodiment exhibits excellent transmittance in the UV wavelength range of 300 nm or less than the 0.7 mm thick soda-lime glass substrate and the 0.7 mm thick LCD glass substrate. Can be.

Transmittance (%) Wavelength (nm) Polysilazane Plate
(0.3mm) Soda-lime glass substrate (0.7mm) LCD glass substrate
(0.7mm) 400 88.4 81.7 89.4 380 88.0 80.5 89.0 360 87.1 79.6 88.1 340 85.0 72.9 85.7 320 82.5 46.1 79.4 300 72.0 6.2 65.3 280 50.0 0.1 42.1 260 29.0 0.1 14.7 240 10.0 0.0 0.3 220 1.2 0.0 0.1 200 0.1 0.0 0.1

Meanwhile, in the first embodiment, the UVLED device 100 discloses an example in which the UVLED chip 10 is coated and sealed with a liquid polysilazane material, but the present invention is not limited thereto. For example, as shown in FIG. 7, the encapsulation unit 160 including the lens 163 made of polysilazane may be formed to protect the UVLED chip 110.

Referring to FIG. 7, the UVLED device 200 according to the second embodiment includes a UVLED chip 110, a mounting substrate 130, and an encapsulation unit 160, and the encapsulation unit 160 includes a support 161. A lens 163 made of polysilazane is provided.

The UVLED chip 110 is mounted on the mounting substrate 130. In this case, the mounting substrate 130 may include a poly resin (PP) substrate, an epoxy resin substrate, a composite base material substrate, a flexible or flexible base material substrate, a ceramic base material substrate, and the like. Metal Cored Base Material substrates may be used.

The UVLED chip 110 is mounted on the mounting substrate 130 and is electrically connected to the mounting substrate 130 through the metal wire 150.

The encapsulation unit 160 covers the UVLED chip 110 and the metal wire 150 on the mounting substrate 130. The support 161 of the encapsulation unit 160 is formed on the mounting substrate 130 surrounding the UVLED chip 110, and an opening 165 is formed on the upper portion of the mounting substrate 130 to expose the UVLED chip 110. The lens 163 of the encapsulation unit 160 is made of a polysilazane encapsulant and is installed to cover the opening 163 of the support 161 to cover the UVLED chip 110.

At this time, the height of the support 161 installed on the mounting substrate 130 is at least higher than the height of the highest point of the metal wire 150 with respect to the top surface of the mounting substrate 130. A reflection layer may be formed inside the support 161 to reflect ultraviolet rays generated from the UVLED chip 110 to the lens 163. Alternatively, the support 161 itself may be made of a material capable of reflecting ultraviolet rays. In addition, a diffuser plate may be installed under the lens 163 to diffuse ultraviolet rays incident from the UVLED chip 110 to the lens 163 and send them to the lens 163. In addition, a heat sink for dissipating heat generated while driving the UVLED chip 110 may be installed under the mounting substrate 130.

While the present invention has been described with reference to several preferred embodiments, these embodiments are illustrative and not restrictive. It will be understood by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.

10: UVLED Chip
30: substrate
40: wiring
41: front wiring
42: back wiring
43: joint wiring
50: bump
60: encapsulation
100: UV LED element
110: UVLED Chip
130: substrate
160: encapsulation
161: support
163: Lens
165 opening part
200: UV LED element

Claims (6)

As a sealing material for UVLED elements,
An encapsulant for a UVLED device comprising a polysilazane of a polymer type composed of a polymer in which nitrogen and silicon atoms cross exclusively. A mounting board;
A UVLED chip mounted on the mounting substrate;
An encapsulation portion of a polymer type polysilazane (Polysilazane) made of a polymer exclusively intersected with nitrogen and silicon atoms, covering the UVLED chip on the mounting substrate;
UVLED device comprising a. The method of claim 2,
The encapsulation part is a UVLED device, characterized in that the liquid polysilazane is applied on the mounting substrate to cover the UVLED chip. The method of claim 2, wherein the encapsulation portion,
A support that surrounds the UVLED chip and is formed on the mounting substrate and has an open portion at which the UVLED chip is exposed;
A lens made of polysilazane (Polysilazane) material installed to cover the opening of the support to cover the UVLED chip;
UVLED device comprising a. A preparation step of preparing a mounting substrate;
A mounting step of mounting a UVLED chip on the mounting substrate;
An encapsulation step of forming an encapsulant covering the UVLED device by applying a polymer-type encapsulant of a liquid polysilazane material composed of a polymer exclusively intersected with nitrogen and silicon atoms on the mounting substrate;
UVLED device manufacturing method comprising a. The method of claim 5, wherein the encapsulation step,
Applying an encapsulant of a liquid polysilazane material to cover the UVLED device on the mounting substrate;
Curing the applied encapsulant at room temperature to 200 degrees to form the encapsulation portion;
UVLED device manufacturing method comprising a.

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