Graphic to explain LED phosphor blending technology: teach you to stay away from misunderstanding

First of all, everyone is a bit misunderstood in the process of mixing powder! Take a look at the CIE chart before mixing:

(1) Find the desired wavelength of the phosphor; when we need a color temperature segment or an X, Y coordinate point, then we need to know the wavelength of the blue chip we use. When we know the chip wavelength we use (chip wavelength 460nm in the figure) and know the coordinate point to be done (x0.44 y0.41), then the chip wavelength point and the coordinate point x, y to be reached on the CIE diagram Click on a straight line and extend to the upper CIE wavelength point. At this time, the wavelength extension point is the wavelength of the phosphor we need (target phosphor wavelength ~585nm). Therefore, to achieve this color coordinate, you need to use this wavelength of phosphor.

2) When we find the wavelength of the target phosphor, we must find the corresponding phosphor to do it, but if only one phosphor is used, the color development is low, so we need to use two or more phosphors to mix such as red powder + Green powder (red powder + green powder according to the principle of superimposed color mixing of light can obtain the desired target phosphor wavelength), how to choose two kinds of phosphors? How to mix the ratio of two kinds of phosphors? This involves the color coordinates needed to be made What is the target phosphor wavelength and the color rendering index required? The appropriate ratio of red and green powder can be used to obtain the desired wavelength of the phosphor. If the Ra requirement is higher, a longer wavelength red phosphor such as 650 nm can be used. Red powder (the higher the spectrum, the higher the color rendering index). With the green powder with a wavelength of about 520 nm, it is easy to do more than 90 indicators. (When looking for the desired target phosphor wavelength, according to the subheading (1) method, the product has been tested to obtain a coordinate point and a straight line extending to the wavelength above the CIE with the wavelength of the blue chip; if the wavelength of this point If the wavelength of the target phosphor is longer than the wavelength of the target phosphor, it is necessary to reduce the ratio of the red phosphor, and if it is shorter than the target wavelength, the ratio of the red phosphor is increased).

3) When the appropriate red and green powder is found and the proportion of the target phosphor is also found (the ratio of red powder to green powder does not change), if the coordinate point of the product still deviates from the required coordinate point, you can observe it on CIE. At this time, the color coordinates of the product are basically in line with the color coordinate point you want, the wavelength of the blue chip, and the wavelength of the target phosphor. At this time, only the ratio of silica gel to phosphor needs to be adjusted (red powder + green powder). The phosphor concentration is increased when the color coordinates are lower than the target coordinates, and the phosphor concentration is decreased when the color coordinates are higher than the target coordinates.

summary:

1) When the phosphor is blended, it is actually the wavelength of the yellow powder required for mixing.

2) Don't just want to increase or decrease the single x or y value. The increase or decrease of x and y is determined by the wavelength of your phosphor, which is the color coordinate and the slope of the blue chip wavelength.

3) When the wavelength of the phosphor is determined, the increase and decrease of the color coordinate is related to the phosphor concentration.

4) The ratio of red powder to green powder is only to determine the desired target phosphor wavelength, that is, the slope of the color coordinates.

5) The slope is correct, then adjust the concentration to get the coordinate area you want.

Suggest:

1. Ra<85 in the case where the color rendering index is not high, it is recommended to use greenish yellow powder + red powder to do it. The advantage is that the light effect is high and easy to control.

2. In the case where the color rendering index requires a higher Ra>90, it is recommended to use red powder plus green powder. The disadvantage is that the light efficiency is low.

3. If the color rendering index is higher than Ra>9 and you want to have a higher light efficiency, it is recommended to use yellow powder + green powder + red powder. The disadvantage is: low consistency and difficult to control.

There are many details about phosphor blending. I won't say much here. I hope I can help you.