LEDinside recently conducted an in-depth interview with Liquidleds Lighting Corp (Liquidleds) CEO, Mr. Kun-Yuan Chiang (Chiang), in relation to the industry of LED.
Liquidleds has been awarded the “golden medal” for its invention of “High Power LED Light Bulbs Packaging with Liquid Immersed Heat Management Solution”, which not only enhances LED illumination, but also improves the LED heat dissipation, adjusts the LED light direction and reduces the LED cost by “Moscow International Salon of Industrial Property Archimedes”.
Chiang, the inventor of “disposable heat pad”, specializes in LED heat dissipation design including its newly creative solution associated with heat management of which are combined with the use of “liquid” and “thermal pad”, and also holds many KSFs (Key Successful Factors) and patents.
AC LED which is suitable for interior light is needed
”When Liquidleds was established, it tried many ways to develop new technologies of LED heat dissipation and accumulated many design knowhow”, said Chiang.
Liquidleds had its first contact with high power LED in 2001, and obtained “LUXEON LED”, which is formed by LED lenser, reflective cup, and glass glue, from Lumileds US. The heat dissipation of “LUXEON LED” is designed with a high conduction substrate and is packaged with integrated thermoelectrical module. Later, Liquidleds had continued to use a variety of high power LED, and still tried to find a good heat dissipation material.
Chiang had tried and tested almost 2,000 types of materials and completed the method of heat dissipation of LED lamp by using special liquid and thermal pad, also providing a high luminous efficiency to this lamp. For now is to wait for a proper AC LED. However, Seoul Semiconductor launched its new product of AC LED in 2007 just in the wake of related studies on AC LED being published. Liquidleds has immediately contacted and cooperated with them; thus, a brand new AC LED lamp integrated with the heat dissipation solution provided by Liquidleds being formed. At that day, we saw 2W and 4W LED lamps associate with good light shapes and luminous efficiencies. The temperature difference between lamp temperature and room temperature is around 20 degrees centigrade.

Advantages and disadvantages of AC LED
But why is the AC LED? “Because AC LED is workable for household electricity without installing the AC to DC converter”, said Chiang. So, it can save the cost of converters. Also, since the life span of converter is shorter than that of LED components; therefore, it is possible that a LED lamp should malfunction only because of a broken converter, but not of its ended product life. Another distinctive feature of AC LED is its manufacturing has been processed by the area-array pad, which will take 60 turns / s with a 60Hz alternating current, and also makes the life span of AC LED longer than that of DC LED.
The DC LED has been commonly used as the flashlight which is a battery-powered device; therefore, it is quite suitable for the feature of DC LED since no additional converter being required.
However, there are two disadvantages of AC LED. One is that its luminous efficiency is not higher than DC LED’s. It is because that DC LED is still the mainstream product. It is possible that the luminous efficiency of AC LED will catch up with or even exceed that of DC LED in the future. And the second one is the electric shock of AC LED. Therefore, when designing the heat dissipation of AC LED lamps, the thermal pad can not be exposed and should be placed somewhere inside the LED lamps. By doing so, the heat of the thermal pads will be released by liquids. That is also the core design value of Liquidleds.
Mr. Chiang also mentioned that when he contacted Seoul Semiconductor, they did not notice that this LED heat dissipation solution can benefit LED light bulbs. They used to say the application range of AC LED could be wide. However, Chiang still believes that AC LED is suitable, applicable for interior lights, and LED street lamps.
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Biography of Kun-Yuan Chiang
Kun-Yuan Chiang is General Manager and President of Liquidleds Lighting Corp. Prior to founding Liquidleds Lighting Corp , Kun-Yuan Chiang was Products Manager, Color Star Inc., Taiwan , responsible for the new product development program of next generation LED solution . During the period at Color Star Inc, he works with an excellent RD and product team to finish many innovative projects and new LED product solution. In this role, his RD team got many patterns and awards in LED field.
Previous positions held by Kun-Yuan Chiang include Hsin-Tao Power Station Project Senior Field Superintendent, Taiwan, and later Start-up Engineer, Bechtel Overseas Corp., Kun-Yuan Chiang is a graduate of the Long-Far Technology University of Taiwan where he received a BS in Mechanic in 1981 and 1983 respectively. He spent his early years in LED RD research and got many internal awards& patterns at past 10 years. His unique insight of the technology, combined with his strategic thinking and new product development experience, will ensure that Liquidleds Lighting Corp increases its worldwide reputation for delivering high power AC LED lighting solution to LED industry.
Media contact:
- Name : Michael Yu
- Title : Vice President
- Mail : miyu@liquidleds.com.tw
- office phone : 886-2-2834-6227