Upward-lighting multicolor LEDs in the CL-V501 Series from Citizen Electronics have improved color mixing, come in a small package, and exhibit high brightness. Multicolor LEDs have three dies of RGB (red, green and blue) in one package. This lets them generate various colors, including white, and are used for illumination or as indicators in many kinds of products such as digital devices. In recent years, applications for illumination in game devices, keyboards for personal computers and amusement devices have been expanding. The number of devices that contain a lens and light guide to create a complicated lighting expression has increased. With this background, smaller, high-brightness LEDs are required, and good color mixing properties when more than two dies are lighted simultaneously, is an important factor so as not to damage the design and functionality of the device.
Through our unique packaging technology based on high-density packaging, we have realized a high color mixing property which conventional packages were unable to achieve. Downsizing and high-brightness are also achieved enabling customers to use a wide variety of expressions they require.
Main LED characteristics include:
１．Natural white color realized by high color mixing property. White color generated by lighting RGB dies in conventional multicolor LEDs had poor color mixing. Thus, in some cases, a RGBW LED was used in which a white (W) LED is added to an RGB device. This solution makes the LED package larger and circuit design of the device complicated and was expensive. However, by developing the composition of raw materials and adopting a new manufacturing method, we have succeeded in controlling directivity in the device itself. The natural white color is realized with this high color mixing property. As the light source does not generate color breakup, the design is improved. Even in cases where a lens and light guide plate are used, it is easier for developers to create designs because the light source itself has color mixing.
２．Both high-brightness and small size are realized, and luminous efficacy per unit area is doubled. We have further developed our high-density packaging technology to achieve a small package with good color mixing properties. Compared with our conventional product, the area of the LED is reduced by 30%, and luminous area is reduced by 50%.
This downsizing contributes to space-saving of the mounting area of the device, and the doubling in luminous efficacy per unit area can reduce energy consumption.
The CL-V501 dimensions are 1.6×1.4 ｍｍ. Mounting area is 2.24 mm２ (Luminous area is 1.34２).
Applications include illumination and indicators for game devices, keyboards for personal computers, home appliances, hobby goods, displays, ambient lighting for automobiles, and colored lighting. Mass production begins in January 2022.
Citizen Electronics Co., Ltd., https://ce.citizen.co.jp/e/