Toshiba LED bulbs using more than 100 LED chips installed in the COB structure large package

Toshiba lighting in September 30, 2009 released the LED bulb 8.7W ordinary bulb type equivalent to 60W incandescent bulbs, the total luminous flux of solar color products 810lm, luminous efficiency of 93lm/W. To this end, the product uses side by side to install more than 100 dozens of mW grade small LED COB (Chip On Board) structure large package. The goal of the LED bulb development is to "make the total luminous flux equal to that of incandescent bulbs" (Toshiba lighting LED division LED planning director Sano Hiroshi). Prior to the LED bulb, even if the company claims to be equivalent to 60W incandescent bulbs products, but also means that the light bulb is the same as the brightness of the 60W incandescent bulbs, the light emitted by the bulb is lower. This time, in order to make the total luminous flux is equivalent to a white bulb, the total luminous flux needs to be raised to 810lm, equivalent to the company's previous products 1.4 to 1.5 times. Figure 1: LED lighting package manufacturing steps of the 2:COB graph structure (implementation lead bonding) in order to achieve the total luminous flux, the new Toshiba lighting using COB structure. The company's past LED bulbs are the 1W scale of several large LED chip packaging, and then embedded in the LED bulb. If you use this structure to make the total luminous flux to achieve this goal, then the number of equipment on the need for a substantial increase in the required installation area is likely to "fill the entire LED bulb" (ibid.). And heat is also more difficult. Therefore, the use of the product in terms of the installation area and heat dissipation favorable COB structure. First of all, the structure should be more than 100 LED chips on the bottom board of the packaging board, namely 15mm square. At this point, the size of the LED chip, the number of configuration intervals need to be optimized through thermal simulation, on this basis to make the shape of the whole as close as possible to the square. Then, the chip is made of wire bonding, and after the phosphor is coated. In order to achieve COB structure. Large flat package can become mainstream in addition to the Toshiba lighting, equipped with a large, flat type white LED package in the LED light bulb in the way released in September 10, 2009 Matsushita products had been used. Prior to the majority of LED bulbs need to be installed in the lamp 4 ~ 6 5mm square, the input power of 1W grade white LED package, in the future, equipped with 1 large LED is expected to become mainstream. Large white LED package has the advantage of being able to expand the heat dissipation area of the package. The heat of the white LED package is easy to conduct to the shell, as far as possible to suppress the temperature rise of the blue LED chip when the light is turned on, so that the luminous efficiency is kept in a high state. In contrast, in the LED lighting, the installation of a number of 1W white LED package in the form of high degree of freedom due to the high degree of freedom of the lighting equipment manufacturers. Because of the design of various shapes of LED lighting, the design of small LED packaging is limited. A LED industry insiders said that the use of multiple 1W class package brings the advantages of freedom of design for LED bulbs are not applicable. The metal mouth of the LED bulb has been determined to be the same as the existing light source, and, even if the shape of the LED bulb is changed, it is still "close to the incandescent bulb". In other words, LED lighting appliances design freedom is not high. After the loss of freedom of design, large white LED packaging on the energy efficiency for LED lighting will show the advantages. In addition to the advantages mentioned earlier, there is a view that, because the light loss is small, so the LED bulb is more suitable for the use of large white LED package. Because of the large white LED package close to the surface light source, LED lighting common "glare" less. In general, LED lighting requires the installation of diffuse light to prevent glare. But the suppression of glare will cause the loss of light. LED insiders said that the large white LED package so you can use less glare, high light transmittance of the shell, which can increase the luminous flux of LED itself to spread outside of the lamp, so as to improve the luminous efficiency of the bulb.