Rectangular Microlens Array Having High Sag for Multi Chip LED Packaging

2006 ◽  
Vol 326-328 ◽  
pp. 1491-1494 ◽  
Author(s):  
Won Kyu Jeung ◽  
Chang Hyun Lim ◽  
Tae Hoon Kim ◽  
Seog Moon Choi
Keyword(s):  
Mass Production ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Large Diameter ◽  
Optical Loss ◽  
Microlens Array ◽  
Wafer Level ◽  
Rectangular Shape ◽  
Replication Method ◽  
Optical Extraction

A novel rectangular shape microlens array having high sag for solid-state lighting is presented. The rectangular shape of proposed microlens can maximize the fill factor of silicon based light-emitting-diode (LED) packaging and minimize the optical loss through the reduction of unnecessary reflection at the same time. Microlens, which has high sag, over 3 75 μm and large diameter, over 3 mm can enormously enhance output optical extraction eff iciency. Moreover wafer level packaging technology is adopted to improve the aligning accu racy and mass production of LED packaging. This wafer level microlens array can be direc tly fabricated on LED packaging using replication method. It has many advantages in optica l properties, low cost, high aligning accuracy, and mass production.

scholarly journals Fabrication of Multiscale-Structure Wafer-Level Microlens Array Mold

2019 ◽  
Vol 9 (3) ◽  
pp. 487 ◽  
Author(s):  
Shuping Xie ◽  
Xinjun Wan ◽  
Xiaoxiao Wei
Keyword(s):  
Low Cost ◽  
Form Factors ◽  
Cost Effective ◽  
Microlens Array ◽  
Practical Method ◽  
Reduced Form ◽  
Wafer Level ◽  
Polycrystalline Aluminum ◽  
Microlens Arrays ◽  
Multiscale Structure

The design and manufacture of cost-effective miniaturized optics at wafer level, usingadvanced semiconductor-like techniques, enables the production of reduced form-factor cameramodules for optical devices. However, suppressing the Fresnel reflection of wafer-level microlensesis a major challenge. Moth-eye nanostructures not only satisfy the antireflection requirementof microlens arrays, but also overcome the problem of coating fracture. This novel fabricationprocess, based on a precision wafer-level microlens array mold, is designed to meet the demandfor small form factors, high resolution, and cost effectiveness. In this study, three different kinds ofaluminum material, namely 6061-T6 aluminum alloy, high-purity polycrystalline aluminum, and purenanocrystalline aluminum were used to fabricate microlens array molds with uniform nanostructures.Of these three materials, the pure nanocrystalline aluminum microlens array mold exhibited auniform nanostructure and met the optical requirements. This study lays a solid foundation for theindustrial acceptation of novel and functional multiscale-structure wafer-level microlens arrays andprovides a practical method for the low-cost manufacture of large, high-quality wafer-level molds.

scholarly journals Design and Fabrication of Wafer-Level Microlens Array with Moth-Eye Antireflective Nanostructures

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 747 ◽  
Author(s):  
Shuping Xie ◽  
Xinjun Wan ◽  
Bo Yang ◽  
Wei Zhang ◽  
Xiaoxiao Wei ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Production Efficiency ◽  
Low Cost ◽  
Microlens Array ◽  
Wafer Level ◽  
Lens Array ◽  
Wafer Level Packaging ◽  
High Production ◽  
Aspherical Lenses ◽  
Profile Accuracy

Wafer-level packaging (WLP) based camera module production has attracted widespread industrial interest because it offers high production efficiency and compact modules. However, suppressing the surface Fresnel reflection losses is challenging for wafer-level microlens arrays. Traditional dielectric antireflection (AR) coatings can cause wafer warpage and coating fractures during wafer lens coating and reflow. In this paper, we present the fabrication of a multiscale functional structure-based wafer-level lens array incorporating moth-eye nanostructures for AR effects, hundred-micrometer-level aspherical lenses for camera imaging, and a wafer-level substrate for wafer assembly. The proposed fabrication process includes manufacturing a wafer lens array metal mold using ultraprecise machining, chemically generating a nanopore array layer, and replicating the multiscale wafer lens array using ultraviolet nanoimprint lithography. A 50-mm-diameter wafer lens array is fabricated containing 437 accurate aspherical microlenses with diameters of 1.0 mm; each lens surface possesses nanostructures with an average period of ~120 nm. The microlens quality is sufficient for imaging in terms of profile accuracy and roughness. Compared to lenses without AR nanostructures, the transmittance of the fabricated multiscale lens is increased by ~3% under wavelengths of 400–750 nm. This research provides a foundation for the high-throughput and low-cost industrial application of wafer-level arrays with AR nanostructures.

Realization of Mass Production of Microlens Array by Hot Embossing on Silicon Substrate

2010 ◽  
Vol 139-141 ◽  
pp. 1562-1565
Author(s):  
Xi Qiu Fan
Keyword(s):  
High Resolution ◽  
High Throughput ◽  
Silicon Substrate ◽  
Mass Production ◽  
Low Cost ◽  
Microlens Array ◽  
Hot Embossing ◽  
High Fidelity ◽  
Optical Performance ◽  
Large Area

Tradition lithographic techniques to produce micrlens array are complicated and time consuming. Due to the capability to replicate nanostructures repeatedly in a large area with high resolution and uniformity, hot embossing has been recognized as one of the promising approaches to fabricate microlens array with high throughput and low cost. This paper introduces processes to realize fabricating microlens array in mass production by direct hot embossing on silicon substrate. The mold is fabricated by multi-photolithography and etching steps and polymethyl methacrylate (PMMA) is chosen as the resist. Processes include coating, heating, pressing, etc. Fidelity and optical performance of the embossed microlens array were measured. High fidelity and fine optical performance of the embossed microlens array demonstrate the possibility of hot embossing to fabricate microlens array in mass production.

scholarly journals A 40 Mb/s VLC System Reusing an Existing Large LED Panel in an Indoor Office Environment

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1697
Author(s):  
Xicong Li ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvánovec ◽  
Paul Anthony Haigh
Keyword(s):  
Modulation Depth ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Data Communication ◽  
Experimental System ◽  
Digital Signal ◽  
Visible Light Communication ◽  
Cost Driver ◽  
Limiting Factors ◽  
Light Sources

With advances in solid-state lighting, visible light communication (VLC) has emerged as a promising technology to enhance existing light-emitting diode (LED)-based lighting infrastructure by adding data communication capabilities to the illumination functionality. The last decade has witnessed the evolution of the VLC concept through global standardisation and product launches. Deploying VLC systems typically requires replacing existing light sources with new luminaires that are equipped with data communication functionality. To save the investment, it is clearly desirable to make the most of the existing illumination systems. This paper investigates the feasibility of adding data communication functionality to the existing lighting infrastructure. We do this by designing an experimental system in an indoor environment based on an off-the-shelf LED panel typically used in office environments, with the dimensions of 60 × 60 cm2. With minor modifications, the VLC function is implemented, and all of the modules of the LED panel are fully reused. A data rate of 40 Mb/s is supported at a distance of up to 2 m while using the multi-band carrierless amplitude and phase (CAP) modulation. Two main limiting factors for achieving higher data rates are observed. The first factor is the limited bandwidth of the LED string inside the panel. The second is the flicker due to the residual ripple of the bias current that is generated by the panel’s driver. Flicker is introduced by the low-cost driver, which provides bias currents that fluctuate in the low frequency range (less than several kilohertz). This significantly reduces the transmitter’s modulation depth. Concurrently, the driver can also introduce an effect that is similar to baseline wander at the receiver if the flicker is not completely filtered out. We also proposed a solution based on digital signal processing (DSP) to mitigate the flicker issue at the receiver side and its effectiveness has been confirmed.

Demonstration of wafer‐level light emitting diode with very high output power

2014 ◽  
Vol 50 (25) ◽  
pp. 1970-1972 ◽  
Author(s):  
Yibin Zhang ◽  
Fei Xu ◽  
Desheng Zhao ◽  
Hongjuan Huang ◽  
Wei Wang ◽  
...  
Keyword(s):  
Output Power ◽  
Light Emitting Diode ◽  
High Output Power ◽  
Wafer Level ◽  
Light Emitting ◽  
Very High ◽  
High Output

Organic Light Emitting Material Direct Writing by Nanomaterial Enabled Laser Transfer

2009 ◽  
Vol 1179 ◽  
Author(s):  
Seung Hwan Ko ◽  
Heng Pan ◽  
Nipun Misra ◽  
Costas Grigoropoulos
Keyword(s):  
Mass Production ◽  
Laser Energy ◽  
Light Emitting Diode ◽  
Nanoparticle Size ◽  
Temperature Sensitive ◽  
Conductive Heat ◽  
Direct Writing ◽  
Light Emitting ◽  
Laser Transfer ◽  
Organic Light

AbstractOrganic light emitting material direct writing is demonstrated based on nanomaterial enabled laser transfer. Through utilization of proper nanoparticle size and type, and the laser wavelength choice, a single laser pulse could transfer well defined and arbitrarily shaped tris-(8-hydroxyquinoline)Al patterns ranging from several microns to millimeter size. The unique properties of nanomaterials allow laser induced forward transfer at low laser energy (0.05 J/cm2) while maintaining good fluorescence. The technique may be well suited for the mass production of temperature sensitive organic light emitting devices.The combined effects of melting temperature depression, lower conductive heat transfer loss, strong absorption of the incident laser beam, and relatively weak bonding between nanoparticles during laser irradiation result in the transfer of patterns with very sharp edges at relatively lower laser energy than commonly used, thus inducing minimal damage to the target organic light emitting diode material with no evidence of cracks. This technique can be applied to a broad range of laser wavelengths with proper selection of nanoparticle size and size distribution, as well as the material type. Additionally, nanomaterial enabled laser transfer may be particularly advantageous for the mass production of temperature sensitive devices.

scholarly journals Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Chia-Chin Chiang ◽  
Jian-Cin Chao
Keyword(s):  
Optical Fiber ◽  
Mass Production ◽  
Low Cost ◽  
Optical Fiber Sensor ◽  
Whispering Gallery Mode ◽  
Solution Concentration ◽  
Fiber Sensor ◽  
Average Sensitivity ◽  
Whispering Gallery ◽  
The Right

An optical fiber solution-concentration sensor based on whispering gallery mode (WGM) is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and anR2linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

Porphyrin doping of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex for electroluminescence

2013 ◽  
Vol 17 (05) ◽  
pp. 351-358 ◽  
Author(s):  
Mohammad Janghouri ◽  
Ezeddin Mohajerani ◽  
Mostafa M. Amini ◽  
Naser Safari
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Energy Levels ◽  
Orbital Energy ◽  
Homogeneous Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Fundamental Structure ◽  
Organic Light

A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex ( Q2SnCl2 , Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/ Q2SnCl2/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q2SnCl2 is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP): Q2SnCl2 (75nm)/ Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.

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