TWI606745B - Process for preparing transparent ceramic plates of phosphorescent - Google Patents

Description

Process for preparing transparent phosphorescent ceramic plates

The present invention relates to a method of preparing a transparent phosphorescent ceramic plate, and more particularly to a method of preparing a transparent phosphorescent ceramic plate which is simple and can improve the yield.

The term "LED" as used in the specification is an abbreviation of a light-emitting diode, and means a pn junction structure using a semiconductor to fabricate a small number of carriers (electrons or holes) to be implanted, and to emit light by recombining the above. Diode.

The term "LD" as used in this specification is an abbreviation for laser diode, which means a laser diode fabricated by a semiconductor, which is used when a large number of carriers are injected into a semiconductor, and when electrons and holes are recombined and released. The luminescence effect obtained by energy.

Optical semiconductor devices, such as LED devices and LD illuminators, have optical semiconductor devices, such as LED devices or LD devices, and a phosphor layer disposed on the optical semiconductor device. The optical semiconductor device emits light by an optical semiconductor device, for example, by a colored mixed light of yellow light obtained by wavelength conversion of blue light of a phosphor layer and some blue light in phosphorescence.

Optical semiconductor devices, which are dominated by LED devices, include an LED package in which the LEDs are packaged in a transparent encapsulating material; and a phosphor strip laminated on the upper surface thereof. The phosphor ribbon has a phosphor layer, and an acrylic pressure-sensitive adhesive layer laminated on the other surface thereof, and the phosphor layer is adhered to the surface of the LED package via the adhesive layer. However, the phosphorescent tape is easily denatured because its temperature is easily increased by the LED light, which causes the brightness of the LED device to become weaker. Therefore, in a phosphorescent adhesive sheet, the phosphor layer is formed of a phosphorescent ceramic plate as a phosphorescent ceramic plate.

However, the existing ceramic plate is prepared as shown in Fig. 2, and a raw material powder composed of cerium oxide, aluminum oxide, and garnet oxide particles is prepared, and the obtained raw material powder is mixed with a water-soluble adhesive resin. To the obtained mixture, distilled water was additionally added to wet-mix, and then the mixture was sintered to prepare a yttrium-aluminum-garnet (hereinafter referred to as "YAG") precursor, which was dried in an oven to form a precursor. A ceramic green sheet is then heated and sintered in a heated and high temperature vacuum furnace to produce a phosphorescent transparent ceramic plate. However, it takes a long time to manufacture a final sheet, and the yield is a problem.

Based on the above, we have found that when a transparent ceramic plate is prepared by using the existing solid phase method, the YAG phosphor is ground after the solid phase synthesis, the preparation method is simple and the yield is improved, and the present disclosure is completed accordingly.

According to an embodiment of the present disclosure, a transparent phosphorescent ceramic plate is prepared by grinding a small particle YAG phosphor to 1 μm or less, then manufacturing (molding) into a plate, and sintering the resultant.

The object and quality of the present disclosure are apparent from the following description of the embodiments and the accompanying drawings, wherein: FIG. 1 is a flow chart showing the preparation of a transparent ceramic plate according to the present disclosure; and FIG. 2 is a view showing the preparation of an existing transparent ceramic. Flow chart of the plate; Figure 3 shows the YAG powder particle size distribution data obtained by using the particle size analyzer before grinding; Figure 4 shows the YAG powder particle size distribution data obtained by using the particle size analyzer after grinding; Figure 5 is a comparison of the spectra between a transparent ceramic plate according to the present disclosure and a transparent ceramic plate prepared using an existing method (Fig. 2) at different cerium concentrations.

In the following, the disclosure will be described in detail, and the following examples or examples are for illustrative purposes only, and the scope of the disclosure is not limited thereto.

According to an embodiment of the present disclosure, a method of preparing a transparent phosphorescent ceramic plate includes, as shown in FIG. 1, grinding a small particle YAG phosphor to 1 μm or less by grinding; the ground YAG phosphor Drying in an oven; applying a pressure to the dried ground YAG phosphor to form a plate; and sintering and post-treating the molded plate.

In accordance with the present disclosure, a YAG phosphor is ground, preferably using a ball mill. If the phosphor is not ground to 1 μm or less, the thickness of the plate may be uneven, which may result in stability and reliability when used in high-output light-emitting diodes (LEDs) and laser diodes (LD). degree. Figure 3 shows the particle size distribution of YAG powder obtained by using a particle size analyzer before grinding. According to Fig. 4, the YAG powder particle size distribution data obtained by using a particle size analyzer after grinding is shown.

According to the present disclosure, the dried YAG phosphor is dried in an oven, preferably at a temperature ranging from 100 ° C to 150 ° C for 1 to 24 hours.

According to the present disclosure, the molding of the applied pressure is preferably carried out using a cold equalization (CIP) method at a pressure ranging from 1000 MPa to 3000 MPa.

According to the present disclosure, the sintering is preferably carried out in a reducing environment or in an air atmosphere furnace in the temperature range of 1400 ° C to 1800 ° C for 8 hours to 15 hours.

According to the present disclosure, the post-treatment of the sintered transparent ceramic plate is preferably carried out by using an auto polishing machine to polish the surface in a surface polishing process.

When the transparent ceramic plate of the present disclosure is produced, cerium is preferably used in an amount of from 0.01 mol to 0.03 mol as an activator. Table 1 below compares the radiant intensity (1 m) between a transparent ceramic plate according to the present disclosure and a transparent ceramic plate (Fig. 2) prepared using an existing method at different activator concentrations. As can be seen from Table 1, the radiant intensity of the transparent ceramic plate prepared by the method of the present disclosure is quite excellent.

Figure 5 is a comparison of the spectra between a transparent ceramic plate according to the present disclosure and a transparent ceramic plate prepared using an existing method (Fig. 2) at different cerium concentrations.

The method for preparing a transparent phosphorescent ceramic plate can reduce complicated processes, has excellent uniform plate thickness due to precise edge preparation, achieves low color distribution, and can achieve high color contrast of 100:1 or higher, and reduces heat. The color coordinates move, with excellent uniformity of illumination angle, solve the binning problem through phosphorescence screening before the board is installed, and when used in high output light-emitting diodes (LEDs) and laser diodes ( LD) ensures stability and reliability.

As described above, the present disclosure has been described with reference to the embodiments. However, it is understood that those skilled in the art can adjust and change the present disclosure without departing from the spirit of the appended claims.

Claims (4)

A method for preparing a transparent phosphorescent ceramic plate, comprising: grinding a small particle YAG phosphor to 1 μm or less by grinding; drying the ground YAG phosphor in an oven; for the dried mill The broken YAG phosphor is pressed to form a plate; and the molded plate is sintered and post-treated. The method of claim 1, wherein the dried YAG phosphor is dried in an oven at a temperature ranging from 100 ° C to 150 ° C for 1 to 24 hours. The method of claim 1, wherein the molding of the applied pressure is performed using a cold equalization (CIP) method at a pressure ranging from 1000 MPa to 3000 MPa. The method of claim 1, wherein the sintering is carried out in a reducing environment or in an atmosphere using an atmosphere furnace in a temperature range of 1400 ° C to 1800 ° C for 8 hours to 15 hours.