High Voltage WireLED Powered Directly by Mains 230 Volts

For the need of energy saving, LEDs are taking more and more space in lighting modules. Moreover, LEDs add several applications to the lighting function, smartness, dimming, bio photonic applications, a lot of fields that none former light sources could reach [1]. The manufacturers of course must keep the target of making a device compatible with the standards in terms of safety first, but moreover the compactness and reliability with the well-known thermal issues, depending on the wall plug efficiency of the component. In order to manage all the mentioned points, as often, packaging is the key point if one seeks to maximize the lifetime of a LED based luminaire. Indeed, because they are aware of the existing technologies and comparison thanks to quick information available on the Internet, today's customers cannot accept to pay a more expensive light source that have lower performance than the former lighting technologies [2]. The paper that we propose describes the manufacturing and the packaging of a LED device made from GaN micro wires compatible with direct mains powering on the 230 Volts-50 Hz network. We show why the heterogeneous stack to manufacture the lighting device, coupled with the high voltage input is a big challenge. Once the front side wire LEDs patterning is finished, many technological steps remain in order to deliver a WLP assembly ready for the back-end assembly process. The carrier bonding, the back side processing for N and P contacts patterning, the hybridization by flip chip technology using copper bumps or solder balls are roughly described with the related issues. Final thermal and electrical characterizations were conducted to evaluate the performances of the high voltage LED device.