PENGARUH DIMENSI GEOMETRIK LAMPU LED TERHADAP PERSEPSI KECERAHAN

2013 ◽  
Vol 3 (2) ◽  
pp. 41
Author(s):  
Andrea Marisi ◽  
Revantino Revantino
Keyword(s):  
Solid State ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Solid State Lighting ◽  
Light Emitting ◽  
Printed Circuit ◽  
Surface Mounting

Perkembangan teknologi di bidang Solid State Lighting selama dekade terakhir membuat diversifikasi penggunaan Light Emitting Diode untuk pelayanan pencahayaan umum. Balai Besar Bahan dan Barang Teknik sejak tahun 2011 telah melakukan penelitian dan pengembangan lampu LED berbasis Surface Mounting Device (SMD) 5050. Pada perancangan Printed Circuit Board (PCB) untuk memasangkan LED-smd tersebut, dilakukan analisis dimensi geometrik yang optimal sehingga dapat memancarkan cahaya ke segala arah dan memberikan persepsi kecerahan yang lebih baik. Untuk perancangan PCB tersebut, dipilih 2 (dua) model berbentuk silinder dengan memperhatikan rasio antara tinggi dan diameter alas. Dari pendekatan sumber titik dan perhitungan eksitansi luminus, diperoleh bahwa model dengan rasio ≈ 1 menghasilkan persepsi lebih cerah terhadap visual manusia.Kata kunci : dimensi geometrik, pendekatan sumber titik, eksitansi luminus, persepsi kecerahan

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

scholarly journals Machine vision based in-process light-emitting diode chip mounting system

2018 ◽  
Vol 51 (7-8) ◽  
pp. 293-303 ◽  
Author(s):  
Chao-Ching Ho ◽  
You-Min Chen ◽  
Po-Chieh Li
Keyword(s):  
Machine Vision ◽  
Printed Circuit Board ◽  
Vision System ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Robot Arm ◽  
Light Emitting ◽  
Printed Circuit ◽  
Delta Robot ◽  
A Charge

Background: In this study, a machine vision–based method was developed for automated in-process light-emitting diode chip mounting lines with position uncertainty. In order to place the tiny light-emitting diode chips on the pattern of a printed circuit board, a highly accurate mounting process is achieved with online feedback of the visual assistance. Methods: The system consists of a charge-coupled device camera, a six-axis robot arm, and a delta robot. The lighting system is a critical point for the in-process machine vision problem. Hence, designing the optimal lighting solution is one of the most difficult parts of a machine vision system, and several lighting techniques and experiments are examined in this study. In order to commence the mounting process, the light-emitting diode chip targets inside the camera field were identified and used to guide the delta robot to the grabbing zone based on the calibrated homography transformation. Efforts have been focused on the field of machine vision–based feature extraction of the chip pins and the holes on the printed circuit board. The correspondence of each other is determined by the position of the chip pins and the printed circuit board circuit pattern. The image acquisition is achieved directly online in real time. The image analysis algorithm must be sufficiently fast to follow the production rate. In order to compensate for the uncertainty of the light-emitting diode chip mounting process, a visual feedback strategy in conjunction with an uncertainty compensation strategy is employed. Results: Finally, the light-emitting diode chip was automatically grabbed and accurately placed at the desired positions. Conclusion: On-line and off-line experiments were conducted to investigate the performance of the vision system with respect to detecting and mounting light-emitting diode chips.

Maker Chemistry: Exploring Redox Reactions in Introductory Laboratory through Light-Emitting Diode Printed Circuit Board Fabrication

2019 ◽  
Vol 97 (2) ◽  
pp. 490-496
Author(s):  
Scott L. Wallen ◽  
Jaspreet Dhau ◽  
Robert Green ◽  
Laura B. Wemple ◽  
Troy Kelly ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit

Numerical and experimental analysis of a heat-pipe-embedded printed circuit board for solid state lighting applications

2017 ◽  
Vol 32 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Thamer Khalif Salem ◽  
Ferina Saati Khosroshahi ◽  
Mehmet Arık ◽  
Mohammad O. Hamdan ◽  
Mete Budakli
Keyword(s):  
Solid State ◽  
Heat Pipe ◽  
Experimental Analysis ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Solid State Lighting ◽  
Printed Circuit

Chip-On-ACB (Anodized Circuit Board) Package for High Power Light-Emitting Diode

2006 ◽  
Vol 3 (2) ◽  
pp. 67-72
Author(s):  
Kyuho Shin ◽  
Suho Shin ◽  
Soon Cheol Kweon ◽  
Kihwan Kwon ◽  
Seogmoon Choi ◽  
...  
Keyword(s):  
Dielectric Layer ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Electric Signal ◽  
Anodized Aluminum ◽  
Metal Base ◽  
Light Emitting ◽  
Aluminum Oxide Layer

A new light-emitting diode (LED) package module based on anodized circuit board (ACB) is developed in this study. ACB represents the selectively anodized aluminum board, in which the aluminum oxide layer, formed by anodizing process, serves as a dielectric layer and the electric signal lines are formed on it. LED chips can be directly attached to the metal pads on the aluminum core of ACB, which acts as p-electrode and at the same time easily spreads out the heat generated from the chips. The use of ACB in LED packaging has the benefit that ACB provides an excellent heat dissipation path from junction to board. This characteristic cannot be obtained from metal-core printed circuit board (MC-PCB), because it inevitably has a dielectric layer for electrical insulation of signal lines from metal base, which acts as a blocking layer in the heat path. By using the thermal transient method, the thermal resistance of the LED package (from junction to board) is measured to be about 4 °C/W. Also, we have performed the simulation of heat conduction, of which the results agree well with the experimental results. This chip-on-ACB LED package module has a potential application as a back light unit for display panel.

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