The maturation of LED technology and lighting applications have allowed flip-chips to become the star of 2013. Genesis Photonics Inc. (GPI) has been producing flip chip products for over three years. In 2013, the company expanded into the new field of flip chip packaging and its development direction has been technological vertical integration. Elimination of wire bonding during the manufacturing process can effectively reduce LEDs damage risks. GPI plans to continue introducing flip chips into special application markets for street lights, tunnel lighting, and factory lighting, which require products with high reliability.
GPI's vertical integration crosses into flip chip packaging
The effect of the company’s strategy is slowly showing after three years of developing flip chips. Compared with lateral die and vertical flip chips in the past, flip chips omits wire bonding during packaging. The LED package component‘s gold thread is a key cause for efficiency loss in LEDs. Gold thread can break under high temperatures environments or in environments with huge temperature differences, which often leads to failed LED products. Aside from simplifying package manufacturing, elimination of bonding wire from packages will also reduce efficiency loss for LEDs.
The company’s extension into flip chip packaging is to provide clients comprehensive services. GPI flip chips manufacturing process uses a gold-tin eutectic direct bonding method where the chip is stuck on to a ceramic substrate, eliminating the package process. Using this type of package method, flip chips have the advantage of lower sheet resistance, low thermal resistance, and elimination of bonding wire. Low sheet resistance allows for high luminosity to be reached and is suitable for high electrical currents. The special characteristic of low heat resistance is that it is has heat dissipation advantages and is able to be used in high powered applications. Eliminating bonding wire can increase reliability and reduce package size.
China's haze problem contributes to growing street light trend of using warm white light
Flip chip products have high current and heat dissipation features making them suitable for use in high powered applications, which increases special luminaire industries willingness to adopt these products. Flip chip products are suitable applications for street lights, tunnel lights, wall wash lights, and industrial lights, which all require support from highly reliable products.
In the past, street lights used 5700K white lights, but the transmission of white light was not good enough due to the serious haze problems in China, GPI pointed out. There has been a recent transition to use warm white light for street lights within the industry. The industry is already demanding 4000k products. Future color temperature for warm white light used in street lights could drop to 3000k levels.
High color temperature luminous efficacy can reach 90lm/w and warm white light 85ml/w according to Chinese street light system specs. Since LED package components introduction into luminaires requires secondary optics in system designs, there can be a loss of 20-30 percent in luminous efficacy. Therefore, keeping within the luminous efficacy range for the lighting system, high color temperature LED package components must reach 130lm/w and 125lm/w for warm white lights.
White light luminous efficacy is around 140lm/w and warm white light is around 120lm/w. GPI current monthly production capacity for flip chip products is 3KK. Future production expansion plans will depend on market changes and client demands.
