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As known to all, photometric and colorimetric quality of LED illumination mainly depends on LED chip, phosphor and sealant. The investigation on failure mechanism of the three parts carries critical meanings for improving reliability of LED production. This paper mainly focus on reliability and failure mechanism of the three kinds of phosphor and three kinds of sealant which are wildly used in high...
High voltage LED (HVLED) is a LED chip configuration that comprises multiple LED units in series, and offers higher luminous output than that of conventional LED chip configurations. Due to the high luminous output and, accordingly, an elevated junction temperature, the thermal performance of HVLED must be enhanced by the flip chip assembly with high-thermal conductivity underfill. To maximize the...
With more implementation of LED in lighting and communication applications, increasing demand for function enrichment and miniaturization has emerged. Existed technologies are highly challenged. System-in-package (SiP) technology is very promising in terms of function integration and cost reduction. In this paper, a novel SiP platform for LED system with integrated driver and wireless control function...
Light Emitting Diodes (LEDs) as an emerging light source has been rapidly developed due to its considerable advantages including high energy efficiency, extremely long life and environmentally friendly. Since packaging accounts for the major part of the total cost, a novel molding process for wafer level LED packaging will be presented in this paper, which could decrease the total cost by the wafer...
Market size of high-brightness LED lighting has been rapidly growing upon the continual improvement of quantum efficiency and light extraction. However some key breakthroughs must be made before this technology can be fully adopted into the broad market, such as efficient thermal dissipation and low manufacturing cost. A major portion of cost of an LED module falls in the packaging processes after...
In this paper, a mechanical lock is first proposed and designed for LED silicone lens mounting. Since LED has many new applications in areas such as automobile headlight, micro-projector and local network optical communication, a potential serious issue must be solved. Due to the poor adhension between silicone and mostly materials including silicon, silicone lens may drop off from the silicon substrate...
After the first white light-emitting diodes (WLEDs) became commercially available, much attention has been paid to the development of WLEDs because of their extensive applications in solid lighting. Compared with traditional lighting, WLEDs have more advantages, such as high efficiency, long lifetime, fast response and environmental-friendliness [1-3]. It has been widely used in signals, displays...
This study proposes a novel silicon-based LED packaging module with a photo-sensing element. The photosensitive component and the base structure of LED die were directly fabricated on the silicon wafer by microfabrication processes with ion doping and inductively coupled plasma etching processes, respectively, to achieve miniaturization, integration, and low-cost smart LED packaging modules. The subsequent...
LED (light-emitting diode) has many advantages over traditional lighting source such as higher electrical efficiency, faster response, and free of hazardous, which has been attracting more and more interesting from all of world. LED technology has achieved remarkable progress during latest years already. However, high price is still the main block for its wide application.
Silicon-based packaging for light emitting diodes (LEDs) is the tendency of packaging for improving high-power LED performance. In this paper, a simple and high efficient wafer level packaging (WLP) based on silicon with TSV is proposed. Monte-Carlo ray-trace method is implemented to analyze the effect of the size of silicone lens on light extraction efficiency (LEE). The results show that LEE of...
The three-dimensional (3D) light-emitting diodes (LEDs) integration package based on silicon with through silicon vias (TSV) attracts a lot of attention because of a better performance, lighter package, and higher integration density. Two main kinds of LED chip including conventional chip (CC) and vertical chip (VC) encapsulated in silicon platform with and without a reflector cup are analyzed through...
In this paper, we investigate a novel Chip-On-Board (COB) process for wafer level LED packaging using micro glass-bubble caps and silicon substrates. The COB packaging process is firstly studied experimentally, which consists of the following steps. First, a silicon substrate with lead lines is prepared. Second, LEDs are mounted on the silicon substrate followed by wire-bonding. Third, phosphor is...
High-power light emitting diodes (LEDs) are found in a number of applications in high-volume consumer markets, such as illumination, signalling, screen backlights, automotives, and others, because of the numerous advantages of LEDs, including low power cost, long life span, and high efficiency. During the manufacturing process, the high-power LED chips are subjected to mechanical and thermal loadings...
In this paper an improved LED (Light emitting diode) packaging structure was proposed, which is based on COB (Chip On Board) technology. This research mainly analyzed the thermal reliability of a 4×4 square LED die array with COB technology during temperature load. Simple intuitive for observation, two specific red glue curing profiles were compared with different curing temperature, curing time,...
Phosphor converted LEDs (pc-LEDs), which employ blue LEDs with yellow phosphor deposition to generate white light illumination is a widely used solid-state lighting source. This paper presents the integration of two major processes, namely, phosphor screen printing and moldless encapsulant dispensing, for wafer level pc-LED packaging. In the present study, the processing procedures and parameters...
LEDs (Light Emitting Diode) have a high potential to replace the conventional light bulb as the long-life, energy efficient, environmentally friendly and multi-use light source in the future. Using flip-chip (FC) technology, the thermal dissipation and luminescence efficiency of high-power LEDs can be improved. Therefore FC packaging also attracts great research interests for high brightness LEDs...
We demonstrate optofluidic packaging of silicon microchips using image processing-based optofluidic maskless lithography (IP-OFML). Optofluidic maskless lithography (OFML) is a dynamic photopolymerization technique for free-floating microstructures within a fluidic channel using a MEMS spatial light modulator. OFML via computer vision-aided image processing enables individual polymer packaging of...
c-axis oriented GaN nanowires (NWs) grown on Si(111) using nitrogen plasma assisted molecular beam epitaxy (MBE) offer promising new approaches for realizing efficient LED technology. The nanowires grow remarkably free of defects, suggesting that eventual LED structures may operate with high quantum efficiencies. Furthermore, the dense NW morphology offers LED configurations with high light extraction...
Multi-physics multi-scale modeling issues in various stages of the LED manufacturing, 3D-SiP, and nano interconnects have been discussed. Molecular dynamics (MD) and finite element method (FEM) have been used to study the scale effect of the material properties and the prediction of the module behaviors which are critical to LED fabrication. We propose a new concept to integrate multi-physics/multi-scale...
This research describes the truncated micro-pyramid reflective cavity for light emitting diodes (LEDs) packaging and increasing LEDs' heat dissipation. Research went through different microstructure profiles related to thermal effect in LEDs' packaging. Microstructures based on the silicon bulk micromachining provide unique truncated micro-pyramid reflective cavity geometry for LEDs assembly. Etching...
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