A PoF and statistics combined reliability prediction for LED arrays in lamps

In this work, a physics-of-failure (PoF) reliability prediction methodology is combined with statistical models to consider the interaction between the lumen depreciation and catastrophic failures of LEDs. The current in each LED may redistribute when the catastrophic failure occurs in one of LEDs in an array, thus affecting the operation...

The Lifetime Prediction of LED Drivers and Lamps

Light-Emitting Diodes (LEDs) have become a very promising alternative lighting source with the main advantages of a longer lifetime and a higher efficiency than traditional ones. However, the LED lamp’s lifetime is compromised by its driver’s reliability. Although extensive studies have been made on the reliability of LEDs, the research on the...

Effect of Sintering Pressure on the Porosity and the Shear Strength of the Pressure-Assisted Silver Sintering Bonding

The microstructure, thickness, porosity, and shear performance of the silver (Ag) sintering layers under different sintering pressures were investigated. Experimental results demonstrated that the thickness and the porosity of the sintering layer decreased when the sintering pressure varied from 5 MPa to 30 MPa. This densification phenomenon...

A probabilistic physics-of-failure reliability assessment approach for integrated LED lamps

This work studies the effect of randomness of LED's lumen depreciation on reliability of the entire LED lamp. An integrated LED light bulb is selected as carrier of the proposed method. A PoF based lumen depreciation model and electronic-thermal simulations are introduced for reliability prediction. The normal distribution is used to describe...

Reliability Prediction of Integrated LED Lamps with Electrolytic Capacitor-Less LED Drivers

This chapter investigates the reliability of the integrated LED lamps with electrolytic capacitor-less LED drivers. Firstly, the impact of the interaction between the degradations of the LED light source and the driver on the lumen depreciation is studied. The electronic-thermal simulation was carried out to obtain the history of temperatures of...

Stress analysis of pressure-assisted sintering for the double-side assembly of power module

Purpose: Crack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship among stress distributions, sintering sequences and sintering pressures during the sintering processes. Design/methodology/approach: Three sintering sequences, S(a)...