2016 13th China International Forum on Solid State Lighting (SSLChina)最新文献

{"title":"Failure early detection in SSL manufacturing","authors":"Xiuzhen Liu, G. Tao","doi":"10.1109/SSLCHINA.2016.7804351","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804351","url":null,"abstract":"With long-life-time of LED lamps, it takes long time to get feedback from field about failure information. We need develop test method, and adopt them in manufacture process to make \"early detection\" of the failures caused by the variations in component and production process. This paper describe some dominant failures modes we found in market, and some typical tests method used in the manufacturer side to early detection and prevent such failures","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115134048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation behaviors and reliability of high power GaN-based white LEDs with different structures","authors":"H. Cao, Jiajia Fu, Lixia Zhao, Xuejiao Sun, Baojuan Sun, Junxi Wang, Jinmin Li","doi":"10.1109/SSLCHINA.2016.7804355","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804355","url":null,"abstract":"Highly stress tests were carried out for GaN-based high power white LEDs with different structures, including traditional lateral, vertical as well as flip-chip LEDs. During the tests, all the electrical, optical and thermal properties were measured in-situ for each LED. The results show that for lateral LEDs, the structure property of LED epitaxial layer is still the key factor that influences the optical degradation behavior. With similar structure properties and leakage current, the failure mechanism will be similar and the activation energy is close to each other. In addition, it is shown that the vertical and flip-chip LEDs can improve the heat dissipation effectively, especially at high temperature. Compared the lifetimes of the LEDs with different structures at different stress temperatures, it can be found that the stress temperature play an important role for reliability evaluation. The optimized stress temperature can help to evaluate the reliability more efficiently. The study will give guidance for the future LED design with controllable lifetime. A statement of the problem or situation, and the approach that is taken to resolve it. The second paragraph in the Section should start with a \"line break\" (using the enter/return key), but do not add an extra blank line. The slight indent will clearly define the paragraphs, and the \"ECTC Text\" Style includes a slight spacing (1 point) between paragraphs within the Section. This first Section may also contain a summary of the past developments and background of what is already known, and published elsewhere. This is best summarized in your own paper, with references to other publications containing more-extensive discussions of this background information. [1] The references are placed at the end of the paper. [2] Remember that you should not re-state material that is readily available in the archival literature; simply summarize it, then add a reference or two. Many peer-reviewed papers in our fields have been published in the IEEE Transactions on Components and Packaging Technologies, and on Advanced Packaging — see www.cpmt.org/trans/.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"308 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124392783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A rapid method of estimating the solar irradiance spectra with potential lighting applications","authors":"Y. Gao, J. Dong, O. Isabella, M. Zeman, G.Q. Zhang","doi":"10.1109/SSLCHINA.2016.7804358","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804358","url":null,"abstract":"Diverse solar irradiance spectra can be observed under different conditions of time, date, location, weather, etc. Since the solar irradiance spectrum is required by certain scientific and engineering applications, obtaining accurate spectral data is essential. Measurements by spectrophotometers are able to achieve accurate real-time data with high resolution, but at high expense. While in some engineering applications, the requirements on accuracy and resolution are much lower than that in a typical scientific research. Therefore, a rapid method of estimating the solar spectrum is proposed based on an available spectral model in this paper. In order to achieve fast estimation, we simplify the input parameters of this model into five key inputs, including latitude and longitude, altitude, date and time, sky and ground type. The first three parameters are easy to obtain from GPS and the internet. Sky and ground types include common types of sky and ground, which can be input manually or processed automatically by analyzing a digital image of target sky or ground. The automatic input is realized through dominant color extraction or by training an artificial neural network. Results show that the proposed rapid method can generate different spectral power distributions based on distinct input conditions. Two device frameworks are also proposed to implement the rapid method, which is applicable to many fields. LED lighting is one of the most prominent applications. Users can easily share local sunlight with each other through an APP in mobile phones.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131731298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The application of photoperiodic control of the plant flowering","authors":"Du Jianjun, Liu Shuping, L. Weihong, Chen Tao, S. Chang-bin","doi":"10.1109/SSLCHINA.2016.7804361","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804361","url":null,"abstract":"Photoperiod is an important factor to the inducing plants flowering. This paper presents the analysis in the photoperiodic reaction types approaches of plant flowering. It is pointed out that the photoperiod plays an concrete role in application of plant flowering. Meanwhile, other environment factors are needed to be considered. In order to make the effective development in agricultural planting flowers industry come true, this paper provides a beneficial idea. Moreover, this idea also has a scientific basis for LED manufacturers when producing plant growth lighting.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117254881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of accelerated LED degradation by statistical methods","authors":"Max Wagner, H. Ganev, A. Herzog, Q. Trinh, T. Khanh","doi":"10.1109/SSLCHINA.2016.7804345","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804345","url":null,"abstract":"In the fast developing LED industry, new generations of LED packages are reaching the market in small time spans. In contrast to that some luminaires, especially in street lighting, should be long lasting and uses the same package over many years. That is one reason why standards are developed to be able to provide lifetime values for the customers. The standard method of calculating the lifetime of an LED package uses the mean values of the luminous flux of a certain number of samples. In a time interval (for example 1000 hours) these values are plotted and fitted by a function, in most cases the exponential function of TM-21 [1] is applied. Our results of LED aging show that often there is no such simple function that is able to describe all the degradation curve. Especially at different conditions (temperature, forward current) the course differ and are not always smooth. Another method to investigate the LED aging is based on statistics. This has been successfully applied in the semiconductor technology (e. g. transistors). In that case every LED package itself gives information, because distributions are the main component of the analysis. The Weibull statistic is tested to the data at different conditions. In order to get a failure rate, the value of a certain percentage of the radiant flux has been taken to define this parameter. The acceleration in the aging test is driven by temperature and forward currents. Both parameters have other effects to the different parts of the LED package. Finally, the acceleration is investigated by the Arrhenius method.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115529832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel surface treatment for the sliver ohmic contacts to P-GaN","authors":"Chenglin Qi, Qinjin Wang, Li Wang, Zhiqiang Liu, X. Yi, Jinmin Li, Junxi Wang","doi":"10.1109/SSLCHINA.2016.7804338","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804338","url":null,"abstract":"With the development of the GaN-based light-emitting diodes (LEDs), the need for p-GaN contacts with low resistivity, good thermal stability, and high reflectivity has become more urgent. In this paper, a novel method of surface treatment on p-GaN to form good ohmic contacts between p-GaN and Ag was proposed. We proposed a novel structure with Ag/ultrathin-ITO/p-GaN contact which shows a low contact resistivity as well as a high reflectance attributed to some isolated islands of ITO and the absence of Ni layer. The calculated ρc of the new structure which is lower than 7×10−2W/cm2 based on the CTLM method showed that the Ag/ultrathin-ITO/p-GaN contact has a lower contact resistivity compared to the contact without the ultrathin ITO layer of which the ρc is higher than 2 W/cm2 The Ag film cannot be ripped off by the tape which shows a good adhesion. The LEDs fabricated with this contacts showed a 30% higher luminance at 20mA forward currents as compared to the conventional LEDs.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131154549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the LED control strategy of constant luminous flux based on photoelectric model","authors":"Xu Yu-zhen, Xu Sheng, Hu Xiangyu, L. Weiming","doi":"10.1109/SSLCHINA.2016.7804359","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804359","url":null,"abstract":"In this paper, a new control strategy of LED, Constant Luminous Flux Control(CLFC), is proposed, whose foundation is the Photoelectric model of LED. Taking into account the influence of the temperature, Constant Luminous Flux Control can effectively eliminate LED luminous flux decay, which is verified by the theoretical derivation, simulation analysis and experimental study.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133799816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-power white LED packaging using phosphor-in-glass and its thermal reliability","authors":"Yang Peng, Ruixin Li, Hao-Chun Cheng, Zhen Chen, Mingxiang Chen","doi":"10.1109/SSLCHINA.2016.7804340","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804340","url":null,"abstract":"This paper proposed a yellow YAG:Ce3+ based PiG for high-power white light-emitting diode (WLED) packaging, and its thermal reliability was systematically investigated. The PiG was fabricated by introducing yellow YAG:Ce3+ phosphor embedded with borosilicate glass through screen-printing and low-temperature sintering. The thermal aging tests of PiG were carried out and compared with the conventional phosphor-in-silicone (PiS). After aging of 200°C for 500 h, the photoluminescence (PL) intensity of PiG is only reduced by 4.3%, which is much smaller than the PiS of 26.2%. In addition, The PiG-based WLEDs achieve the stable optical performance under the various aging conditions of PiG. The aging results show that the prepared PiG exhibits superior heat resistance characteristic, which induces the excellent thermal reliability for PiG-based WLEDs.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115680523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Control of LED luminaires — An overview of competing wired and wireless standards","authors":"F. Greenfeld, Kin-man. Shum","doi":"10.1109/SSLCHINA.2016.7804357","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804357","url":null,"abstract":"LED lighting is rapidly displacing entrenched lighting technologies as the preferred method of illumination. Not only must the light output be controlled, but energy conservation and safety goals are pushing sensor/monitoring functions such as ambient light, occupancy, temperature, smoke, carbon monoxide, and other detectors into the luminaires. LED lighting also offers the capability of proximal data transmission using modulation techniques analogous to other photonic methods. The simple light fixture is evolving into a sophisticated system requiring centralized coordination and control, and there are many rival communication standards, wired and wireless, competing for acceptance. The choice of which standard or standards to adopt is complicated by the variety and breadth of the application space which may range from a single room up to the public lighting of an entire city. Furthermore, the availability of supporting infrastructure and the economics of installation and maintenance must be considered in the selection process. This paper presents an overview of the more common communication standards and discusses the merits of each relative to specific applications. In particular, Power of Ethernet (PoE) is presented as a solution for much of the application space.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115776771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel chip-on-board white light-emitting diode design for light extraction enhancement","authors":"Huayong Zou, Jiaqi Wang, Mingxin Feng, Brian Shieh, S. Lee","doi":"10.1109/SSLCHINA.2016.7804342","DOIUrl":"https://doi.org/10.1109/SSLCHINA.2016.7804342","url":null,"abstract":"In this study, in order to resolve the low light extraction issue of chip-on-board light-emitting diodes (COB LED), the phosphor layers in COBs were molded into a pattern of cavity arrays to minimize the trapped radiant power by total internal reflection (TIR). Monte-Carlo ray-tracing simulation was performed for extraction efficiency optimization with the same color coordinates (x, y). It was found in the simulation that, with the increase of the top diameter and the depth of cavity arrays, the light extraction efficiency may increase. Furthermore, with the increase of the bottom diameter of cavity arrays, the phosphor consumption could be reduced. The present study reveals the relationship between the light emitting structure of phosphor layer and the light extraction efficiency. This research provides a useful design guideline for the optimization of LED optical performance.","PeriodicalId":413080,"journal":{"name":"2016 13th China International Forum on Solid State Lighting (SSLChina)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132911602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}