PRINTED WIRING ASSEMBLIES : RELIABILITY STRESS SCREENING
Page 1 Scope . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Field of application . . . . . . . . . . . . . . . . . . . 2 3 Reference . . . . . . . . . . . . . . . . . . . . . . . 2 4 Definitions . . . . . . . . . . . . . . . . . . . . . . . . 2 5 Sampling . . . . . . . . . . . . . . . . . . . . . . . 3 5.1 Sample preparation . . . . . . . . . . . . . . . . . 3 5.2 RSS time planning . . . . . . . . . . . . . . . . . 4 5.3 Reduced RSS process determination . . . . . . . 4 6 Method of RSS . . . . . . . . . . . . . . . . . . . . 4 6.1 Principle . . . . . . . . . . . . . . . . . . . . . . . 4 6.1.1 Initial RSS test . . . . . . . . . . . . . . . . . 4 6.1.2 Optimum RSS process duration . . . . . . . 4 6.1.3 Function test . . . . . . . . . . . . . . . . . . 4 6.1.4 Pass/failure criteria . . . . . . . . . . . . . . 4 6.1.5 Failure analysis . . . . . . . . . . . . . . . . 5 6.1.6 Selection of stress types and stress levels . . . 5 6.2 Applicable stress types . . . . . . . . . . . . . . . 5 6.2.1 Constant high temperature . . . . . . . . . . 5 6.2.1.1 Passive “bake” process . . . . . . . . 5 6.2.1.2 “Bake” process with applied voltage . . . 6 6.2.1.3 “Bake” process with power dissipation . . 6 6.2.2 Low/high temperature cycling . . . . . . . . . 6 6.2.2.1 Passive temperature cycling . . . . . 6 6.2.2.2 Temperature cycling with power dissipation . . . . . . . . . . . . . . . . 6 6.2.3 Vibration and other mechanical stress . . . . 7 6.2.3.1 Fixed frequency sinusoidal vibration . . . 7 6.2.3.2 Swept frequency sinusoidal vibration . . 8 6.2.3.3 Random vibration . . . . . . . . . . . 8 6.2.3.4 Bump . . . . . . . . . . . . . . . . . 8 6.2.3.5 Other mechanical stresses . . . . . . 8 6.2.4 Combination of temperature cycling and random vibration . . . . . . . . . . . . . . . . . . . . 8 6.2.5 Humidity . . . . . . . . . . . . . . . . . . . . 9 6.2.5.1 Constant high humidity and temperature . . . . . . 9 6.2.5.2 High humidity and temperature cycling . . . . . . 9 6.2.6 Operational stress . . . . . . . . . . . . . . . 9 6.2.6.1 Constant operational stress . . . . . . 9 UDC 621.38
Activation energies and the arrhenius equation
This paper examines the current use of the Arrhenius equation and the activation energies associated with integrated circuits. A short introduction to the Arrhenius equation is given and it is shown how activation energies may be computed from experimental data. 
 
The paper next addresses the following basic question: is it reasonable to extrapolate from high-temperature laboratory life-tests down to use conditions using the Arrhenius equation? The paper shows that the answer to this question in general must be an emphatic no. It is not the validity of the Arrhenius equation as such that is questioned, but its indiscriminate use by reliability practitioners across the electronics industry. 
 
This is not a scientific paper, and no ‘proofs’ are given. The discussion is based on ‘typical’ integrated circuits using published data on the temperature dependence of the hazard rate of such circuits. The paper serves as a warning against thinking that ‘well established practices’ are necessarily scientifically sound.
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.