Preparation method of high-brightness special-shaped PIG

Abstract

The invention belongs to the technical field of LED luminescent materials, and particularly relates to a preparation method of high-brightness special-shaped PIG, and the high-brightness special-shaped PIG is prepared by mixing fluorescent powder and glass powder, forming, calcining, grinding and carrying out special-shaped cutting. The glass ceramic fluorescent sheet is stable in physical and chemical properties, large in optical density, high in brightness and good in light stability, and the fluorescent sheet is easy to manufacture, easy to operate, low in cost, free of pollution and easy for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of LED luminous materials, and in particular relates to a method for preparing a high-brightness special-shaped PIG. Background Art

[0002] White light LED is mainly silicone resin mixed with phosphor, which produces green light, yellow light, and red light through the excitation of blue light, and finally mixes to get white light. At present, white light LED is mainly used in lighting and backlight. With the expansion of the application field of white light LED, the requirements for white light LED are also getting higher and higher. However, due to the poor weather resistance and thermal stability of resin, it brings serious problems of light decay, light color shift, yellowing and aging, which limits the expansion of the application scope of white light LED.

[0003] The thermal conductivity of silicone resin used in traditional packaging is <0.2w / mk, and the thermal stability is poor. When the optical density is too high, the heat generated by the light cannot be conducted out in time, which leads to yellowing and deterioration of the adhesive material. The maximum optical density of the product can only withstand 200lm / mm 2 Therefore, traditional LED packaging products cannot be used in some high-end automotive lighting products. The thermal conductivity of glass ceramic phosphor (PIG) ​​is 1w / mk-20w / mk. Because of its high thermal conductivity and thermal stability, it can quickly conduct heat away, thereby reducing its own temperature. Glass ceramic phosphor can withstand >1000lm / mm 2 Optical density is of great significance in solving many problems of traditional LED packaging, such as poor weather resistance, poor thermal stability, yellowing degradation, and low optical density.

[0004] Conventional glass ceramic phosphor sheets are cut into square and round shapes. The optical properties of the phosphor directly affect the optical properties of PIG. If the optical properties of PIG can be improved through other means without changing the optical properties of the phosphor, the production cost will be effectively reduced. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the present invention provides a method for preparing a high-brightness special-shaped PIG.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] A method for preparing a high-brightness special-shaped PIG is provided, wherein fluorescent powder and glass powder are mixed, and the mixture is molded, calcined and cut into special shapes to obtain the PIG, wherein the softening temperature of the glass powder is 650°C-750°C.

[0008] On the basis of the above technical solution, the present invention can also make the following improvements:

[0009] Furthermore, the special-shaped cutting is performed using a V-shaped knife.

[0010] Furthermore, the angle of the V-shaped knife is 50.96°.

[0011] Further, the method specifically includes the following steps:

[0012] (1) Weighing glass powder and phosphor powder according to a certain proportion, and mixing them after weighing to disperse the phosphor powder into the glass powder;

[0013] (2) placing the uniformly mixed raw materials into a mold, and then forming them through a cold isostatic press to obtain a molded cylindrical embryo;

[0014] (3) Processing the formed cylindrical embryo into a fluorescent cylinder and sintering at low temperature under atmosphere protection;

[0015] (4) cutting the low-temperature sintered fluorescent cylinder into circular fluorescent sheets, and then double-sided grinding and polishing the fluorescent sheets;

[0016] (5) The V-shaped knife is used to cut the circular fluorescent sheet to obtain the high-brightness special-shaped PIG.

[0017] Furthermore, in step (1), the phosphor is YAG:Ce phosphor or α-sialon phosphor, and the ratio of the phosphor to the total weight of the glass powder and the phosphor is 1%wt-90%wt.

[0018] Furthermore, in step (1), the glass powder and the phosphor are fully mixed in a three-dimensional mixer.

[0019] Furthermore, in step (2), the molding pressure in the cold isostatic press is controlled at 180 MPa-200 MPa.

[0020] Furthermore, in step (3), the formed cylindrical embryo is processed into a cylindrical embryo by a lathe, and the sintering temperature is 450°C-500°C.

[0021] Furthermore, in step (4), the fluorescent cylinder is cut into circular fluorescent sheets with a thickness of 180 μm-220 μm.

[0022] Furthermore, in step (4), the fluorescent sheet is double-sided ground and polished to control the thickness of the fluorescent sheet to be 150um±1.5um and the smoothness Ra<0.1um.

[0023] The beneficial effects of the present invention are as follows: the glass ceramic fluorescent sheet of the present invention has stable physical and chemical properties, high optical density, high brightness, and good light stability; the fluorescent sheet is simple to manufacture, easy to operate, low-cost, pollution-free, and easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is a schematic diagram of the structure of a special-shaped PIG cut out according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the square PIG obtained by cutting in Comparative Example 1;

[0026] Figure 3 Schematic diagram of the preparation process of an embodiment of the present invention;

[0027] Figure 4 Thickness measurement data of the glass ceramic fluorescent sheet prepared in Example 1 of the present invention;

[0028] Figure 5 The smoothness measurement data of the glass ceramic phosphor sheet prepared in Example 1 of the present invention;

[0029] Figure 6 Comparison of reliability between traditional packaging and special-shaped phosphor packaging;

[0030] Figure 7 A schematic diagram of the structure of a V-shaped knife used in an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the process of cutting the fluorescent sheet into different shapes in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0033] Example 1

[0034] See also Figure 3 Taking the preparation of 6000K glass ceramic phosphor as an example, the preparation method of the high-brightness special-shaped PIG in this embodiment specifically includes the following steps:

[0035] (1) Weigh 1356 g of glass powder (GYG-15, Shenzhen Zhongchengda Applied Materials Co., Ltd.) and 203.4 g of YAG:Ce yellow phosphor (SGY560, Hild Materials Technology Co., Ltd.), wherein the peak wavelength of the YAG:Ce yellow phosphor is 560 and the particle size D50=32 μm. After weighing, put the raw materials into a three-dimensional mixer for full mixing to disperse the phosphor into the glass powder. Mixing is a very important step in the entire preparation process. Whether the mixing is uniform is directly related to the target concentration of the product. The second is the uniformity of the thickness of the phosphor sheet. The more uniform the thickness, the more concentrated the color temperature of the product and the more stable the luminescence.

[0036] (2) placing the uniformly mixed raw materials into a mold, and then forming them through a cold isostatic press, wherein the forming pressure of the cold isostatic press is controlled at 200 MPa;

[0037] (3) The formed cylindrical embryo is processed into a cylinder by a lathe, and sintered at a low temperature of 500° C. under atmosphere protection, and finally the diameter of the fluorescent cylinder is 100 mm;

[0038] (4) Cut the fluorescent cylinder into 200 μm thick circular fluorescent sheets, and then grind and polish the fluorescent sheets on both sides to control the thickness to 150 μm ± 1.5 μm and the smoothness Ra < 0.1 μm;

[0039] (5) Use a V-shaped knife to cut the circular fluorescent sheet (see Figure 8 ), the angle of the V-shaped knife is 50.96°, and the special-shaped PIG with a lower surface size of 1.10mm*1.10mm is obtained (see Figure 1 , wherein (A) is a top view and (B) is a side view). The V-shaped blade structure used in this embodiment is as follows Figure 7 shown.

[0040] Comparative Example 1

[0041] Different from Example 1, in step (5) of Comparative Example 1, conventional cutting tools are used to cut the fluorescent sheet into square PIGs of 1.10 mm*1.10 mm (see Figure 2 , where (A) is a top view and (B) is a side view).

[0042] Comparative Examples 2-5

[0043] Different from Example 1, Comparative Examples 2-5 respectively use V-shaped knives with angles of 45°, 55°, 61°, and 65° to cut PIG with a lower surface size of 1.10 mm*1.10 mm.

[0044] Figure 4 This is the thickness measurement data of the glass ceramic fluorescent sheet after multi-wire cutting, grinding and polishing in Example 1. The data unit in the figure is mm. 12 points were selected to measure the thickness of the fluorescent sheet, and the thickness error was 3um. This well reflects that the thickness uniformity of the fluorescent sheet is relatively good.

[0045] Figure 5 This is the smoothness data of the glass ceramic fluorescent sheet after multi-line cutting, grinding and polishing in Example 1; 5 points were selected to measure the smoothness of the fluorescent sheet, and Ra was below 0.1um. It well reflects that the surface of the fluorescent sheet is relatively flat; the scattering of PIG is reduced, thereby increasing the transmittance of PIG and improving the optical performance of PIG.

[0046] Table 1 is a comparison of the luminous flux of the same color temperature obtained after the glass ceramic fluorescent sheet of Example 1 was cut into special-shaped PIG packages at different angles. It can be found from the table that with the increase of the angle of the special-shaped cutting tool, the luminous flux of the cut fluorescent sheet shows a trend of first increasing and then decreasing. The angle of the v-shaped knife used in Example 1 is 50.96°, and the luminous intensity of the cut fluorescent sheet is the highest. It can be understood that the fluorescent sheet cut by the v-shaped knife with an angle of 50.96° has the best optical performance after packaging, and the emitted light from the inclined surface of the fluorescent sheet is basically emitted from the light emitting surface 0.73mm*0.73mm after multiple rounds of reflection.

[0047] Table 1 Comparison of luminous flux of the same color temperature obtained after encapsulation of the fluorescent sheets of Example 1 and Comparative Examples 2-5

[0048] Special cutting angle IF(mA) VF(V) Φ(lm) x y Tc(K) Ra 45° 999.3 3.626 345.2 0.3214 0.333 6019 67.4 50° 999.7 3.631 361.5 0.3219 0.3331 6016 67.4 50.96° 999.7 3.621 365.9 0.3213 0.3335 6020 67.4 61° 999.9 3.624 361 0.322 0.334 6019 67.3 65° 999.9 3.628 358.7 0.3218 0.3345 6017 67.2

[0049] Table 2 is a comparison table of the data of the special-shaped cutting, conventional cutting and traditional packaging of the glass ceramic fluorescent sheet in Example 1; it is not difficult to see from the packaging data that the color coordinates of the traditional packaging are much more discrete than the packaging coordinates of the fluorescent sheet, the color temperature range is between 6000-6500K, and the average luminous flux is 338.8lm, the color temperature of the special-shaped fluorescent sheet is concentrated between 6000-6100K, the average luminous flux is 360.8lm, the color temperature of the conventionally cut square fluorescent sheet is concentrated between 5900-6200K, the color temperature error is within the range of 300K, and the average luminous flux is 342.3lm. From Table 2, we can clearly see that the packaging brightness (luminous flux) of the special-shaped fluorescent sheet cut in the embodiment of the present invention is 5 points higher than the brightness of the conventional shape fluorescent sheet, indicating that the special-shaped fluorescent sheet can effectively improve the luminous intensity of the fluorescent sheet.

[0050] Table 2 Comparison of data of special-shaped cutting, conventional cutting and traditional packaging of glass ceramic phosphor sheets in Example 1

[0051]

[0052]

[0053]

[0054] Figure 6 This is a reliability comparison between the traditional package and the special-shaped fluorescent sheet package in Example 1. The luminous brightness of the traditional packaged product decreased by 40% after lighting for 10,000 hours, and the color temperature was 800K higher. However, the light decay and color temperature of the glass ceramic fluorescent sheet packaged product obtained by special-shaped cutting in Example 1 of the present invention remained basically unchanged, indicating that the fluorescent sheet prepared by the present invention has a high luminous stability.

[0055] Example 2

[0056] See also Figure 3Taking the preparation of 1800K glass ceramic phosphor as an example, the preparation method of the high-brightness special-shaped PIG in this embodiment specifically includes the following steps:

[0057] (1) Weigh 1000 g of glass powder (GYG-15, Shenzhen Zhongchengda Applied Materials Co., Ltd.) and 630 g of α-sialon phosphor (YL-600B, Japan Denka), respectively, wherein the peak wavelength of the α-sialon phosphor is 601 and the particle size D50=18 μm. After weighing, put the raw materials into a three-dimensional mixer for full mixing to disperse the phosphor into the glass powder. Mixing is a very important step in the entire preparation process. Whether the mixing is uniform is directly related to the target concentration of the product. The second is the uniformity of the thickness of the phosphor sheet. The more uniform the thickness, the more concentrated the color temperature of the product and the more stable the luminescence.

[0058] (2) placing the uniformly mixed raw materials into a mold, and then forming them through a cold isostatic press, wherein the forming pressure of the cold isostatic press is controlled at 200 MPa;

[0059] (3) The formed cylindrical embryo is processed into a cylinder by a lathe, and sintered at a low temperature of 500° C. under atmosphere protection, and finally the diameter of the fluorescent cylinder is 100 mm;

[0060] (4) Cut the fluorescent cylinder into 200 μm thick circular fluorescent sheets, and then grind and polish the fluorescent sheets on both sides to control the thickness to 150 μm ± 1.5 μm and the smoothness Ra < 0.1 μm;

[0061] (5) Use a V-shaped knife to cut the circular fluorescent sheet. The angle of the V-shaped knife is 50.96° to obtain a special-shaped PIG with a lower surface size of 1.10 mm*1.10 mm (see Figure 1 , wherein (A) is a top view and (B) is a side view). The V-shaped blade structure used in this embodiment is as follows Figure 7 shown.

[0062] Comparative Example 6

[0063] Different from Example 2, in step (5) of Comparative Example 6, conventional cutting tools are used to cut the fluorescent sheet into square PIGs of 1.10 mm*1.10 mm (see Figure 2 , where (A) is a top view and (B) is a side view).

[0064] Comparative Examples 7-10

[0065] Different from Example 2, Comparative Examples 7-10 respectively use V-shaped knives with angles of 45°, 55°, 61°, and 65° to cut PIG with a lower surface size of 1.10 mm*1.10 mm.

[0066] Table 3 is a comparison of the luminous flux of the same color temperature obtained after the glass ceramic fluorescent sheet of Example 2 was cut into special-shaped PIG packages at different angles. It can be found from the table that with the increase of the angle of the special-shaped cutting tool, the luminous flux of the cut fluorescent sheet shows a trend of first increasing and then decreasing. The angle of the v-shaped knife used in the embodiment is 50.96°, and the luminous intensity of the cut fluorescent sheet is the highest. It can be understood that the fluorescent sheet cut by the v-shaped knife with an angle of 50.96° has the best optical performance after packaging, and the emitted light from the inclined surface of the fluorescent sheet is basically emitted from the light emitting surface 0.73mm*0.73mm after multiple rounds of reflection.

[0067] Table 3 Comparison of luminous flux of the same color temperature obtained after encapsulation of the fluorescent sheets of Example 2 and Comparative Examples 7-10

[0068] Special cutting angle IF(mA) VF(V) Φ(lm) x y Tc(K) Ra 45° 999.9 3.658 203.1 0.557 0.416 1791 40.9 55° 999.9 3.653 206.1 0.558 0.417 1789 40.7 50.96° 999.9 3.66 211.8 0.5573 0.4173 1796 40.9 61° 999.9 3.708 208.8 0.5569 0.4162 1792 40.9 65° 999.9 3.644 205.8 0.5577 0.4183 1795 40.5

[0069] Table 4 is a comparison of the data of the special-shaped cutting, conventional cutting and traditional packaging of the glass ceramic fluorescent sheet in Example 2; it is not difficult to see from the packaging data that the color coordinates of the traditional packaging are much more discrete than the packaging coordinates of the fluorescent sheet, the color temperature range is between 1780-1800K, the average luminous flux is 197.46lm, the color temperature of the special-shaped fluorescent sheet is concentrated between 1790-1800K, the average luminous flux is 208.26lm, and the color temperature of the conventionally cut square fluorescent sheet is concentrated between 1780-1800K, and the average luminous flux is 202.6lm. From Table 4, we can clearly see that the packaging brightness (luminous flux) of the special-shaped fluorescent sheet cut in the embodiment of the present invention is 3 points higher than the brightness of the conventionally shaped fluorescent sheet, indicating that the special-shaped fluorescent sheet can effectively improve the luminous intensity of the fluorescent sheet.

[0070] Table 4 Comparison of data of special-shaped cutting, conventional cutting and traditional packaging of glass ceramic phosphor sheets in Example 2

[0071]

[0072]

[0073]

[0074] In Example 1, a 6000k white light fluorescent sheet was prepared using YAG:Ce phosphor, and in Example 2, an 1800k amber light fluorescent sheet was prepared using α-phosphor. The fluorescent sheets prepared using the two different types of phosphors have different luminous intensities, and the luminous intensity of white light is stronger than that of amber. The preparation method of the present invention uses two types of fluorescent sheets obtained by special-shaped cutting, and the luminous brightness is significantly improved compared with the fluorescent sheets obtained by traditional packaging and conventional cutting.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing high-brightness special-shaped PIG, characterized in that: The phosphor powder and glass powder are mixed, and then formed, calcined, ground and cut into special shapes to obtain the product. The softening temperature of the glass powder is 650°C-750°C.

2. The method for preparing high-brightness special-shaped PIG according to claim 1, characterized in that: The special-shaped cutting is performed by using a V-shaped knife.

3. The method for preparing high-brightness special-shaped PIG according to claim 2, characterized in that: The angle of the V-shaped knife is 50.96°.

4. The method for preparing high-brightness special-shaped PIG according to claim 3, characterized in that: The specific steps include: (1) Weighing glass powder and phosphor powder according to a certain proportion, and mixing them after weighing to disperse the phosphor powder into the glass powder; (2) placing the uniformly mixed raw materials into a mold, and then forming them through a cold isostatic press to obtain a molded cylindrical embryo; (3) Processing the formed cylindrical embryo into a fluorescent cylinder and sintering at low temperature under atmosphere protection; (4) cutting the low-temperature sintered fluorescent cylinder into circular fluorescent sheets, and then double-sided grinding and polishing the fluorescent sheets; (5) The V-shaped knife is used to cut the circular fluorescent sheet to obtain the high-brightness special-shaped PIG.

5. The method for preparing high-brightness special-shaped PIG according to claim 4, characterized in that: In step (1), the phosphor is YAG:Ce phosphor or α-sialon phosphor, and the ratio of the phosphor to the total weight of the glass powder and the phosphor is 1%wt-90%wt.

6. The method for preparing high-brightness special-shaped PIG according to claim 5, characterized in that: In step (1), the glass powder and the phosphor are fully mixed in a three-dimensional mixer.

7. The method for preparing high-brightness special-shaped PIG according to claim 6, characterized in that: In step (2), the molding pressure in the cold isostatic press is controlled at 180 MPa-200 MPa.

8. The method for preparing high-brightness special-shaped PIG according to claim 4, characterized in that: In step (3), the formed cylindrical embryo is processed into a cylindrical embryo by a lathe, and the sintering temperature is 450°C-500°C.

9. The method for preparing high-brightness special-shaped PIG according to claim 8, characterized in that: In step (4), the fluorescent cylinder is cut into circular fluorescent sheets with a thickness of 180 μm-220 μm.

10. The method for preparing high-brightness special-shaped PIG according to claim 1, characterized in that: In step (4), the fluorescent sheet is double-sided ground and polished to control the thickness of the fluorescent sheet to be 150um±1.5um and the smoothness Ra<0.1um.

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