The thesis was performed at the lighting company Zpecta AB. Zpecta needed to develop alternative attachment of their LED-luminaire Capella. Today Capella attaches in metal ceilings with four magnets. Zpecta got indications from their customers that there was a need for other attachments. The purpose is to determine the customer’s requirements and the interfaces that are considered for Capella. During the thesis, Capella was only on the market for testing and evaluation. The thesis was initiated to create a specification. The specification would cover all the demands and wishes Zpecta and their customers have. The specification should also contain the regulatory requirements. To find out the requirements for a luminaire, an information research was conducted by visiting customers, researching the Internet, verbal information and by studying literature. Design concepts were developed to attach the Capella to ceilings made of wood, concrete and plaster, with wire suspension, at system ceiling, acoustic ceiling and at 3-circuit track. Capella’s magnetic attachment was tested in order to the specification. The result showed that the magnetic attachment did not meet the requirements. Therefore a solution, that meet the requirements for the magnetic attachment, would be developed and also an alternative design solution for mounting at 3-circuit track. The design concepts were evaluated by using the Pugh selection matrix and a questionnaire. Three design solutions were developed for mounting at 3-circuit track and wire suspension. The design solutions were presented as an assembly in SolidWorks, with a manufacturing method, a FMEA and a cost estimate. For the three design solutions that were developed, there have to be prototypes for testing to get knowledge about how well the design solutions meet the specification. / Examensarbetet utfördes på belysningsföretaget Zpecta AB. Zpecta ville ha hjälp med att ta fram alternativa infästningar av LED-armaturen Capella. I dagsläget fästs Capella i undertak av metall med fyra magneter. Zpecta har fått signaler om att det finns behov av andra infästningar än magnetinfästningen. Syftet är att ta reda på kundens krav på infästningar samt att ta reda på vilka gränssnitt som är aktuella för Capella. Under tiden som examensarbetet utfördes fanns Capella endast på marknaden för utvärdering och för test av LED-armaturen ute hos kund. Examensarbetet inleddes med att ta fram en kravspecifikation. I kravspecifikationen dokumenteras alla regulatoriska krav samt de krav och önskemål som Zpecta och Zpectas kunder har på Capella. För att ta reda på de krav som ställs på en belysningsarmatur gjordes en grundlig informationssökning med hjälp av studiebesök, Internet, muntlig information samt litteraturstudier. Konstruktionskoncept togs fram för att montera Capella i trä-, betong och gipstak, med wireupphäng, i systemundertak och i akustiktak samt i 3-fasskena. Capellas magnetinfästning testades utefter de krav som fanns i kravspecifikationen. Testerna visade att magnetinfästningen inte klarade de krav som ställs på en armaturs infästning i tak. Efter genomförda tester beslutades det att en godkänd lösning för magnetinfästningen skulle tas fram samt en alternativ konstruktionslösning för infästning i 3-fasskena. Med hjälp av Pughs urvalsmatris och en enkät utvärderades konstruktionskoncepten. Tre konstruktionslöningar arbetades fram för infästning i 3-fasskena och med wireupphäng. Konstruktionslöningarna presenteras som en assembly med ingående parter i SolidWorks, lämplig tillverkningsmetod, en FMEA, samt en kostnadsuppskattning. De konstruktionslöningar som togs fram bör det göras prototyper på för test och utvärdering för att kunskap ska fås om hur väl konstruktionslöningarna fungerar.

In this thesis, we will try to grow m-plane InGaN blue light-emitting diodes (LEDs) and discuss the characteristics. First, pure m-plane GaN on the m-sapphire grown by plasma assisted molecular beam epitaxy (PAMBE) had been achieved. ¢½/¢» ratio and the growth temperature are the most important factors in the growth sequence. M-GaN film with better crystal quality was grown successfully by tuning these two factors. Indium composition in the InGaN layer is an important issue in the growth of blue LEDs; In/Ga ratio could affect the bandgap i.e. the target wavelength of a LED. We have to regard the crystal quality and the target wavelength of the InGaN layer in growth procedure. Structural properties were investigated by X-ray diffraction (XRD). XRD measurements showed that the crystal orientation of GaN films was pure m-plane. From cathodoluminescence (CL) spectra, the luminescence wavelength of InGaN layer is in the blue-light range. The crysatalline of m-plane InGaN blue LEDs were analyzed by XRD and Electron Back-Scattered Diffraction (EBSD). Electroluminescence (EL) was measured under the different inject current conditions; the polarization of EL was also measured. Moreover, the current-voltage curve and current-output curve were carried out.

In this thesis, we focus on the light extraction efficiency of LED package. The light extraction efficiency of LED is limited by Fresnel Loss and total internal reflection, which result in the rare amount of luminious flux from LED. In order to improve the light extraction efficiency of high power LED package, we study the design of package structure and the matching refractive index of silicone resins. Instead of using one-layer structure, we use multi-layer structure which can raise the light extraction efficiency and the brightness. In order to destroy the total internal reflection, we change the geometric appearance and the interior structure and furthermore we use the different refractive index of silicone resins to decrease Fresnel Loss. In this work, we use the multi-layer structure whose the refractive indexes of the inner silicone resin and the outer silicone resin are 1.55 and 1.41 respectively. When the geometric appearance is convex, the light extraction efficiency of LED package can reach to 70%. Furthermore, by applying this result on phosphor conversion light emitting diode, we can get high efficiency of white light.

Light emitting diodes (LEDs) are generally used in daily life. Our major target is to increase the brightness of LED. We study the package of white phosphor-conversion light emitting diodes (PC-LEDs) and analyze the effect on the luminous flux and color temperature from different locations and concentrations of phosphor coatings and deposition of phosphor. In this study, the color temperature and luminous flux are measured. When the phosphor is placed on the top of the reflected cup with 1.5% of concentration, or on the bottom with 7% of concentration, or when it fills the reflected cup with 1.5% of concentration, the luminous flux is about 40 lm under the CIE 1931 color coordinate of (0.33,0.33). We also studied the effect on deposition of phosphor of two different viscosities of resin used to package white PC-LED. The luminous flux which is packaged with higher viscosity resin is about 12% higher than the one found with the lower viscosity resin. After two hours of deposition, the luminous flux of the white PC-LED which is packaged with the resin of lower viscosity increased 4%, and the one packaged with the resin of higher viscosity increased 7%.

As the great studies have been made in light emitting diodes, the application becomes more variety for different field. High bright light emitting diodes apply a new light source for fluorescence lifetime measurements. We use confocal scanning microscopy and a high frequency sensitive lock-in amplifier to obtain the electroluminescence image at ten of micrometer. We drive the light emitting diodes by radio frequency signal and observe it. We parallel connection an inductance to match the parasitic capacity in high frequency to obtain better light emitted brightness.

The technology of high-power light-emitting diodes (LEDs) is mature. In this study, the LEDs were aged through high temperature to understand the packaging failure mechanisms under lasting lighting. The Tracepro optics simulation software is also applied to analyze the radiation pattern decay caused by curvature variation and material aging. In the experiment procedure, the LEDs of three manufactures were placed in aging ovens in three different temperatures set at 95¢J, 85¢J, and 65¢J. The experiment results showed that the LED failures were the lens and silicon gel yellowing, silicon gel carbonization, lens slightly chapping, silicon cracks, bubbles generated between lens and silicon gel, and chip damage induced reverse current increase during the aging experiment. We observed the failure mechanism in reduction of optical power at 90%, 80%, 70%, 60%, 50% original power. Furthermore, the failure mechanisms of different from the manufactures is also compared in this work. The LED packages have long lifetime without silicon gel carbonization. In simulation study, a gap of lens deformation showed a reduction at -60¢X~-40¢X and 40¢X~60¢X of the radiation pattern. The LED modules also showed that the silicon gel and PC absorption coefficient increased. Material absorption coefficient increased more in the short wavelength showed 149mcd at ¡Ó60¢X of the radiation pattern.

This thesis aimed to identify the energy use within the Nova Scotia Layer Industry, through auditing and evaluating layer farms. Using the data collected, energy benchmarks were determined; providing a guide for achieving a measure of energy efficiency on farm. Focusing on lighting use within layer barns, this research aimed to identify how lighting is used and offer an innovative method of achieving reduced energy use without impacting hen performance or production levels.

Jag skall i mitt projekt först och främst få erfarenhet av hur det är att samarbeta som designer med ett företag och även få ut en produkt som är klar att använda och som skall kunna säljas i butiker runt om i landet. Den skall följa företagets riktlinjer, vara energisnål och vara funktionell men samtidigt tilltalande. / Produktdesign/Självständigt projektarbete – Examensarbete

The main line pursued is the mechanical stressing of light-emitting diodes (LED's) by pressing on the surface with spherically rounded sapphire probes ranging from 100 μm to 500 1m radius of curvature and with forces up to 50 grams weight on the largest probe, care being taken not to exceed the elastic limit of the material, which is estimated to be about 1.4 x 10^9 pascals (14,000 atmospheres) at the central bottom point of the probe. With the diode under forward bias a very wide range of current is covered from 10 mA to about 100 pA in the light-emitting region and from 100 pA to 100 nA in the generation/recombination region - and across the whole range a small decrease in current of about 1 per cent or less is observed. The classical theory of the distribution of stress by a spherical probe has been investigated by a modern computer technique, and by integration of the stress over the whole of the junction interface it is shown that the decrease in current can be ascribed to the increase in band gap of the semiconductor that is brought about by the axial component of pressure stress at right angles to the interface. With the larger currents in the light-emitting region a further decrease in current of the order of 1 per cent or less can be ascribed to heat conduction from the warm surface of the diode to the probe, thereby. lowering the temperature of the interface. Finally, the electrical characteristics of the diode under reverse bias have been investigated, with incident light playing an important role; in the absence of light the extremely small currents (10^-12 to 10^-10 amp) are consistent with thermal generation of carriers similar to the generation/ recombination mechanism for very low currents in the forward direction.

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