Preparation method of high-brightness special-shaped PIG

Abstract

The application belongs to the technical field of LED luminescent materials, and particularly relates to a preparation method of a high-brightness special-shaped PIG, wherein fluorescent powder and glass powder are mixed, and then the mixture is prepared after forming, calcining, grinding and special-shaped cutting. The glass ceramic fluorescent sheet has stable physical and chemical properties, high light density, high brightness and good light stability. The fluorescent sheet is simple to make, easy to operate, low in cost, pollution-free and easy to be industrially produced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of LED luminescent materials, and particularly relates to a preparation method of a high-brightness special-shaped PIG. BACKGROUND

[0002] White light LED, mainly silicone resin mixed with fluorescent powder, generates green light, yellow light and red light through excitation of blue light, and finally mixed white light. At present, white light LED is mainly applied to lighting and backlight. With the expansion of the application field of white light LED, the requirement for white light LED is also higher and higher. However, the poor weather resistance and thermal stability of resin bring serious problems such as light decay, light color deviation, yellowing and serious aging, which limits the expansion of the application range of white light LED.

[0003] The thermal conductivity coefficient of traditional packaging silicone resin is less than 0.2 w / m.k, and the thermal stability is poor. When the light density is too high, the heat generated by light cannot be conducted out in time, thereby causing yellowing and degradation of the glue material. The maximum light density of the product can only withstand 200 lm / mm 2 . Therefore, the traditional LED packaging product cannot be applied in some high-end automotive lighting products. The thermal conductivity coefficient of glass ceramic fluorescent sheet (PIG) is 1 w / m.k-20 w / m.k. Because of the high thermal conductivity coefficient and thermal stability, the heat can be quickly conducted out, thereby reducing the temperature of the glass ceramic fluorescent sheet. The glass ceramic fluorescent sheet can withstand >1000 lm / mm 2 light density, which is of great significance to solve the problems such as poor weather resistance, poor thermal stability, yellowing and degradation, and low light density of traditional LED packaging.

[0004] The conventional glass ceramic fluorescent sheet is cut into square and circular shapes. The optical performance of the fluorescent powder directly affects the optical performance of the PIG. If the optical performance of the fluorescent powder is not changed, the optical performance of the PIG can be improved through other ways, which will effectively reduce the production cost. SUMMARY

[0005] The application provides a preparation method of a high-brightness special-shaped PIG aiming at the above defects of the prior art.

[0006] The technical scheme for solving the above technical problems is as follows:

[0007] A preparation method of a high-brightness special-shaped PIG, which is prepared by mixing fluorescent powder and glass powder, forming, calcining and special-shaped cutting. The softening temperature of the glass powder is 650-750 DEG C.

[0008] On the basis of the above technical scheme, the application can also be improved as follows:

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

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

[0011] Further, the method comprises the following steps:

[0012] (1) the glass powder and the fluorescent powder are weighed according to the proportion, and after the weighing is completed, the fluorescent powder is mixed into the glass powder;

[0013] (2) the mixed raw materials are put into a mold, and then formed by a cold isostatic pressing machine to obtain a formed cylinder embryo;

[0014] (3) the formed cylinder embryo is processed into a fluorescent cylinder, and low-temperature sintering is carried out under atmosphere protection;

[0015] (4) the fluorescent cylinder after low-temperature sintering is cut into a circular fluorescent sheet, and then the fluorescent sheet is double-ground and polished;

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

[0017] Further, in step (1), the fluorescent powder is YAG:Ce fluorescent powder or alpha-sialon fluorescent powder, and the proportion of the fluorescent powder in the total weight of the glass powder and the fluorescent powder is 1%wt-90%wt.

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

[0019] Further, in step (2), the forming pressure of the cold isostatic pressing machine is controlled at 180MPa-200MPa.

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

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

[0022] Further, in step (4), the fluorescent sheet is double-ground and polished, and the thickness of the fluorescent sheet is controlled to be 150um±1.5um, and the smoothness Ra is less than 0.1um.

[0023] The glass ceramic fluorescent sheet has the advantages of stable physical and chemical properties, large optical density, high brightness, good light stability, simple production, easy operation, low cost, no pollution and easy industrialized production. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1This is a schematic diagram of the irregularly shaped PIG obtained by cutting according to an embodiment of the present invention;

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

[0026] Figure 3 This is a schematic diagram of the preparation process according to an embodiment of the present invention;

[0027] Figure 4 The thickness measurement data of the glass-ceramic fluorescent sheet prepared in Example 1 of this invention;

[0028] Figure 5 The surface finish measurement data are for the glass-ceramic fluorescent sheet prepared in Example 1 of this invention.

[0029] Figure 6 A comparison of the reliability of traditional packaging and irregularly shaped phosphor packaging;

[0030] Figure 7 This is a schematic diagram of the V-shaped blade used in an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the process of irregular cutting of fluorescent sheet in Embodiment 1 of the present invention. Detailed Implementation

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] Example 1

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

[0035] (1) Weigh 1356g of glass powder (GYG-15, Shenzhen Zhongchengda Applied Materials Co., Ltd.) and 203.4g of YAG:Ce yellow phosphor (SGY560, Hilde Materials Technology Co., Ltd.). The YAG:Ce yellow phosphor has a peak wavelength of 560 nm and a particle size D50 of 32 μm. After weighing, put the raw materials into a three-dimensional mixer for thorough 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 directly affects the concentration of the target point of the product. Secondly, it affects the uniformity of the phosphor thickness. The more uniform the thickness, the more concentrated the color temperature of the product and the more stable the luminescence.

[0036] (2) Place the evenly mixed raw materials into the mold, and then form them through a cold isostatic press. The forming pressure of the cold isostatic press is controlled at 200MPa.

[0037] (3) The preformed cylindrical body is machined into a cylinder by a lathe and sintered at a low temperature under atmosphere protection. The sintering temperature is 500℃, and the diameter of the fluorescent cylinder is 100mm.

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

[0039] (5) Cut the circular fluorescent sheet using a V-shaped blade (see...). Figure 8 The V-shaped cutter has an angle of 50.96°, resulting in an irregularly shaped PIG with a lower surface dimension of 1.10mm * 1.10mm (see...). Figure 1 (where (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 As shown.

[0040] Comparative Example 1

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

[0042] Comparative Examples 2-5

[0043] Unlike Example 1, Comparative Examples 2-5 were cut into PIGs with a lower surface size of 1.10mm*1.10mm using V-shaped cutters at 45°, 55°, 61°, and 65°, respectively.

[0044] Figure 4 The thickness measurement data of the glass-ceramic phosphor sheet after multi-wire cutting, grinding, and polishing in Example 1 are shown in the figure. The unit of data in the figure is mm. The thickness of the phosphor sheet was measured at 12 points, and the thickness error was within 3 μm. This well reflects the good uniformity of the phosphor sheet thickness.

[0045] Figure 5 The data shows the surface finish of the glass-ceramic phosphor sheet after multi-wire cutting, grinding, and polishing in Example 1. Five points were selected to measure the surface finish of the phosphor sheet, and the Ra values ​​were all below 0.1 μm. This clearly reflects the relatively smooth surface of the phosphor sheet, reducing PIG scattering and thus increasing PIG transmittance, thereby improving the optical performance of PIG.

[0046] Table 1 compares the luminous flux of the glass-ceramic phosphor sheet of Example 1 after being cut into irregularly shaped PIGs at different angles and packaged, resulting in the same color temperature. The table shows that as the angle of the irregular cutting tool increases, the luminous flux of the phosphor sheet after cutting shows a trend of first increasing and then decreasing. The phosphor sheet cut by Example 1 with a V-shaped knife angle of 50.96° has the highest luminous intensity. This can be understood as the phosphor sheet cut by a V-shaped knife with an angle of 50.96° having the best optical performance after packaging. The light emitted from the inclined surface of the phosphor sheet is basically emitted from the light-emitting surface of 0.73mm*0.73mm after multiple reflections.

[0047] Table 1. Comparison of luminous flux at the same color temperature after encapsulation of phosphor sheets in Example 1 and Comparative Examples 2-5.

[0048] Profiled 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 compares the data of irregular-shaped cutting, conventional cutting, and traditional packaging of the glass-ceramic phosphor sheet in Example 1. It is clear from the packaging data that the color coordinates of the traditional packaging are much more dispersed than those of the phosphor sheet, with a color temperature range of 6000-6500K and an average luminous flux of 338.8 lm. The color temperature of the irregular-shaped phosphor sheet is concentrated between 6000-6100K, with an average luminous flux of 360.8 lm. The color temperature of the conventionally cut square phosphor sheet is concentrated between 5900-6200K, with a color temperature error within 300K, and an average luminous flux of 342.3 lm. Table 2 clearly shows that the packaging brightness (luminous flux) of the irregularly shaped phosphor sheet cut in this embodiment of the invention is 5 points higher than that of the conventionally shaped phosphor sheet, indicating that the irregularly shaped phosphor sheet can effectively improve the luminous intensity of the phosphor sheet.

[0050] Table 2 Comparison of data from irregular cutting, conventional cutting, and traditional packaging of glass-ceramic fluorescent sheets in Example 1.

[0051]

[0052]

[0053]

[0054] Figure 6 This is a reliability comparison between conventional packaging and the irregularly shaped phosphor sheet packaging of Example 1. The conventionally packaged product showed a 40% decrease in luminescence brightness and an 800K higher color temperature after 10,000 hours of illumination. In contrast, the product packaged with the irregularly shaped glass-ceramic phosphor sheet obtained in Example 1 of this invention maintained essentially unchanged light decay and color temperature, indicating that the phosphor sheet prepared by this invention has high luminescence stability.

[0055] Example 2

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

[0057] (1) Weigh 1000g of glass powder (GYG-15, Shenzhen Zhongchengda Applied Materials Co., Ltd.) and 630g of α-Syrone phosphor (YL-600B, Denka, Japan). The α-Syrone phosphor has a peak wavelength of 601 nm and a particle size D50 of 18 μm. After weighing, put the raw materials into a three-dimensional mixer for thorough 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 directly affects the concentration of the target point of the product. Secondly, it affects the uniformity of the phosphor sheet thickness. The more uniform the thickness, the more concentrated the color temperature of the product and the more stable the luminescence.

[0058] (2) Place the evenly mixed raw materials into the mold, and then form them through a cold isostatic press. The forming pressure of the cold isostatic press is controlled at 200MPa.

[0059] (3) The preformed cylindrical body is machined into a cylinder by a lathe and sintered at a low temperature under atmosphere protection. The sintering temperature is 500℃, and the diameter of the fluorescent cylinder is 100mm.

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

[0061] (5) The circular phosphor sheet was cut using a V-shaped cutter at an angle of 50.96° to obtain an irregularly shaped PIG with a lower surface size of 1.10mm*1.10mm (see...). Figure 1 (where (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 As shown.

[0062] Comparative Example 6

[0063] Unlike Example 2, in Comparative Example 6, step (5) involved using a conventional cutting tool to cut the fluorescent sheet into 1.10mm x 1.10mm square PIGs (see Example 6). Figure 2 (where (A) is the top view and (B) is the side view).

[0064] Comparative Examples 7-10

[0065] Unlike Example 2, Comparative Examples 7-10 were cut into PIGs with a lower surface size of 1.10mm*1.10mm using V-shaped cutters at 45°, 55°, 61°, and 65°, respectively.

[0066] Table 3 compares the luminous flux of the glass-ceramic phosphor sheet of Example 2 after being cut into irregularly shaped PIGs at different angles and packaged, resulting in the same color temperature. The table shows that as the angle of the irregular cutting tool increases, the luminous flux of the phosphor sheet after cutting shows a trend of first increasing and then decreasing. The phosphor sheet with the highest luminous intensity was obtained by using a V-shaped knife with an angle of 50.96° in the example. This can be understood as the phosphor sheet cut by a V-shaped knife with an angle of 50.96° having the best optical performance after packaging. The light emitted from the inclined surface of the phosphor sheet is basically emitted from the light-emitting surface of 0.73mm*0.73mm after multiple reflections.

[0067] Table 3 compares the luminous flux of the phosphor sheets obtained after encapsulation in Examples 2 and Comparative Examples 7-10 at the same color temperature.

[0068] Profiled 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 compares the data of irregular-shaped cutting, conventional cutting, and conventional packaging of the glass-ceramic phosphor sheet in Example 2. It is clear from the packaging data that the color coordinates of the conventionally packaged phosphor sheet are much more dispersed than those of the conventionally packaged phosphor sheet, with a color temperature range of 1780-1800K and an average luminous flux of 197.46 lm. The color temperature of the irregularly shaped phosphor sheet is concentrated between 1790-1800K, with an average luminous flux of 208.26 lm. The color temperature of the conventionally cut square phosphor sheet is concentrated between 1780-1800K, with an average luminous flux of 202.6 lm. Table 4 clearly shows that the packaging brightness (luminous flux) of the irregularly shaped phosphor sheet cut in this embodiment of the invention is 3 points higher than that of the conventionally shaped phosphor sheet, indicating that the irregularly shaped phosphor sheet can effectively improve the luminous intensity of the phosphor sheet.

[0070] Table 4 Comparison of data from irregular cutting, conventional cutting, and traditional packaging of glass-ceramic fluorescent sheets in Example 2.

[0071]

[0072]

[0073]

[0074] Example 1 prepared a 6000k white phosphor using YAG:Ce phosphor, and Example 2 prepared an 1800k amber phosphor using α-phosphor. The phosphors prepared by the two different types of phosphors have different luminous intensities, with the white phosphor having a stronger luminous intensity than the amber phosphor. The preparation method of this invention uses irregularly shaped cutting to obtain the two types of phosphors, and compared with phosphors prepared by traditional packaging and conventional cutting, the luminous brightness is significantly improved.

[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 within the protection scope of the present invention.

Claims

1. A method for preparing a high-brightness irregularly shaped PIG, characterized in that, Specifically, the following steps are included: (1) Weigh the glass powder and phosphor according to the proportion, and mix them after weighing to disperse the phosphor into the glass powder. The softening temperature of the glass powder is 650℃-750℃. (2) Place the evenly mixed raw materials into the mold, and then form them by cold isostatic pressing to obtain the shaped column preform; (3) The preformed cylindrical body is processed into a fluorescent cylinder and sintered at low temperature under atmosphere protection; (4) Cut the fluorescent cylinder after low-temperature sintering into circular fluorescent sheets, and then grind and polish the fluorescent sheets on both sides to control the thickness of the fluorescent sheets to be 150um±1.5um and the surface finish Ra<0.1um; (5) The circular fluorescent sheet is cut with a V-shaped knife at an angle of 50.96° to obtain the high-brightness irregular PIG.

2. The method for preparing high-brightness irregularly shaped PIGs according to claim 1, characterized in that, In step (1), the phosphor is YAG:Ce phosphor or α-Ce phosphor, and the phosphor accounts for 1%wt-90%wt of the total weight of glass powder and phosphor.

3. The method for preparing high-brightness irregularly shaped PIGs according to claim 2, characterized in that, In step (1), the glass powder and phosphor are thoroughly mixed in a three-dimensional mixer.

4. The method for preparing high-brightness irregularly shaped PIGs according to claim 3, characterized in that, In step (2), the forming pressure of the cold isostatic press is controlled at 180MPa-200MPa.

5. The method for preparing high-brightness irregularly shaped PIGs according to claim 1, characterized in that, In step (3), the shaped cylindrical blank is machined into a cylindrical blank by a lathe, and the sintering temperature is 450℃-500℃.

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