An Overview of Reliability
An overview of reliability engineering is presented here to serve as an introductory piece for some, or perhaps as a refresher. Much of the discussion here is general in coverage, and may suggest topics for further investigation.
The perspective here is at the electronic product or module level, which typically includes printed circuit board assemblies (PCBAs), power supply modules, software / firmware, product case, and user interface. The analytical and test tools discussed here are generally well suited for application to the electrical module or product hardware.
The intended audience here is the reliability engineer, or engineers wishing to go into that field. Another audience target may be the manager of that reliability engineering function, who wishes to learn more about the field of reliability engineering. The role of these persons is to promote the identification and completion of these reliability engineering tasks. They often act as the interface to other departments such as engineering, quality assurance, marketing, and manufacturing, so as to optimize the project activities related to reliability.
The goals of reliability engineering is to add value to the organization, reduce warranty costs, and satisfy customers, through the enhancement of product life. Activities include product analysis, product testing, failure analysis and reporting with recommendations.
Introduction To HALT - Making Your Product Robust
Reliability is highest when designed into products. One process to test for product reliability is the “Highly Accelerated Life Test” (HALT).
HALT is a test method to discover product design limits and failure modes through a series of increasing stress conditions, utilizing extreme thermal stresses and vibrations. Aimed largely at electronic Printed Circuit board products, it is highly effective in identifying stress operating limits and destruct limits, and in demonstrating failure modes in a matter of days that would normally show up in the field after weeks or months.
This article gives an explanation of what it will do, and what it will not do, and how to plan for it. The article discusses fixturing, equipment, facilities planning, setup, functional verification, and the actual running of the test. It also discusses the importance of failure analysis and corrective action, as well as HASS (Highly Accelerated Stress Screening), the manufacturing screening process based on HALT.