Thermal uniformity of packaging multiple light-emitting diodes embedded in aluminum-core printed circuit boards

2013 ◽  
Vol 53 (4) ◽  
pp. 544-553 ◽  
Author(s):  
Xing-Ming Long ◽  
Rui-Jin Liao ◽  
Jing Zhou ◽  
Zhi Zeng
Keyword(s):  
Printed Circuit Boards ◽  
Light Emitting Diodes ◽  
Circuit Boards ◽  
Light Emitting ◽  
Printed Circuit

A Solder Joint Reliability Model for the Philips Lumileds LUXEON Rebel LED Carrier Using Physics of Failure Methodology

2013 ◽  
Vol 2013 (1) ◽  
pp. 000887-000892 ◽  
Author(s):  
Rudi Hechfellner ◽  
Michiel Kruger ◽  
Tewe Heemstra ◽  
Greg Caswell ◽  
Nathan Blattau ◽  
...  
Keyword(s):  
Solder Joint ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Light Emitting Diodes ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Control ◽  
Circuit Board ◽  
System Level ◽  
Light Emitting ◽  
Printed Circuit

Light Emitting Diodes (LEDs) are quickly evolving as the dominant lighting solution for a wide variety of applications. With the elimination of incandescent light bulbs and the toxic limitations of fluorescent bulbs, there has been a dramatic increase in the interest in high-brightness light emitting diodes (HB-LEDs). Getting the light out of the die, with reliable color, while maintaining appropriate thermal control over a long service life is a challenge. These issues must be understood and achieved to meet the needs of unique applications, such as solidstate-lighting, automotive, signage, and medical applications. These applications have requirements for 15–25 years of operation making their reliability of critical importance. The LUXEON Rebel has been accepted as an industry leading LED product, widely used in Mean-Time-Between-Failure (MTBF) sensitive applications. Customers use various mounting platforms, such as FR4 Printed Circuit Board (PCB), FR4 PCB with thermal via's, Aluminum & Copper Metal Core printed Circuit Boards (MCPCB), Super MCPCB, etc. As in other LEDs, when mounting to a platform where a large Coefficient of Thermal Expansion (CTE) exists between the LED & the PCB, Solder fatigue could become an issue that may affect system level lifetime. In this paper we have examined extreme cases and how a solder joint can impact system level reliability. We have modeled the conditions and formed a means to predict system level reliability. We have compared the prediction modeling with empirical tests for validation of the models. It is vital to understand system level reliability factors to build lighting solutions that match the application and customer expectations. It is impractical to test LEDs and other components for 50k hours ~5 years since the device evolution is much faster than that – on average one LED generation every 12–18 month. Hence we need models and prediction methods …..

scholarly journals PCB Origami: A Material-Based Design Approach to Computer-Aided Foldable Electronic Devices

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Yoav Sterman ◽  
Erik D. Demaine ◽  
Neri Oxman
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Circuit Boards ◽  
Light Emitting ◽  
Printed Circuit ◽  
3D Objects ◽  
Evaluation Strategies ◽  
Embedded Electronics ◽  
User Guidance

Origami is traditionally implemented in paper, which is a passive material. This research explores the use of material with embedded electronics such as printed circuit boards (PCB) as the medium for origami folding to create an interactive folding experience and to generate foldable objects with added functionalities. PCBs are produced as 2D shapes. By folding PCB arrays, it is possible to create 3D objects that contain electronic functions. Conductivity, output devices (such as light emitting diodes) and microcontroller computation can create an interactive folding experience, for user guidance and verification of the folding. We call this approach and methodology PCB origami. The work presented in this paper describes two unique interaction and fabrication techniques for creating and folding electronic materials. We demonstrate prototypes and present verification/evaluation strategies for guiding the user through the folding process.

scholarly journals PCB Origami: A Material-Based Design Approach to Computer-Aided Foldable Electronic Devices

2013 ◽  
Author(s):  
Yoav Sterman ◽  
Erik D. Demaine ◽  
Neri Oxman
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Homogeneous Material ◽  
Circuit Boards ◽  
Light Emitting ◽  
Printed Circuit ◽  
3D Objects ◽  
Evaluation Strategies ◽  
Embedded Electronics

Origami is traditionally implemented in paper of homogeneous material properties. This research explores the use of material with embedded electronics such as PCB (Printed Circuit Boards) as the medium for origami folding in order to create an interactive folding experience and to generate foldable objects with added functionalities. PCBs are produced as 2D shapes. By folding PCB arrays it is possible to create 3D objects that contain electronic functions. Conductivity, output devices (such as Light Emitting Diodes) and microcontroller computation can create an interactive folding experience, for user guidance and verification of the folding. We call this approach and methodology PCB Origami. The work presented in this paper describes two unique interaction and fabrication techniques for creating and folding electronic materials. We demonstrate prototypes and present verification/evaluation strategies for guiding the user through the folding process.

scholarly journals Parametric Compact Thermal Models of Power LEDs

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1724 ◽  
Author(s):  
Marcin Janicki ◽  
Tomasz Torzewicz ◽  
Przemysław Ptak ◽  
Tomasz Raszkowski ◽  
Agnieszka Samson ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Light Emitting Diodes ◽  
Operating Conditions ◽  
Junction Temperature ◽  
Light Sources ◽  
Cold Plate ◽  
Circuit Boards ◽  
Thermal Models ◽  
Light Emitting ◽  
Main Factor

Light-emitting diodes are nowadays the most dynamically developing type of light sources. Considering that temperature is the main factor affecting the electrical and lighting parameters of these devices, thermal models are essential subcomponents of the multidomain models commonly used for simulation of their operation. The authors investigated white power light-emitting diodes soldered to Metal Core Printed Circuit Boards (MCPCBs). The tested devices were placed in a light-tight box on a cold plate and their cooling curves were registered for different diode heating current values and various preset cold plate temperatures. These data allowed the computation of optical and real heating power values and consequently the generation of compact thermal models in the form of Foster and Cauer RC ladders. This also rendered possible the analysis of the influence of the considered factors on the compact model element values and their parametrization. The resulting models yield accurate values of diode junction temperature in most realistic operating conditions and they can be easily included in multidomain compact models of power light emitting diodes.

Slit Effect of Common Ground Patterns in Affecting Cross-Talk Noise between Two Parallel Signal Traces on Printed Circuit Boards

2008 ◽  
Vol 128 (11) ◽  
pp. 657-662 ◽  
Author(s):  
Tsuyoshi Maeno ◽  
Yukihiko Sakurai ◽  
Takanori Unou ◽  
Kouji Ichikawa ◽  
Osamu Fujiwara
Keyword(s):  
Cross Talk ◽  
Printed Circuit Boards ◽  
Common Ground ◽  
Circuit Boards ◽  
Printed Circuit
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