Читать книгу Design for Excellence in Electronics Manufacturing - Cheryl Tulkoff - Страница 36

Getting reliability data from suppliers is a great way to gain experience in using and analyzing reliability data. Suppliers are a good source for ideas and practices that are standard for their commercial off‐the‐shelf (COTS) components. Suppliers are also a free or inexpensive source of education on quality and reliability data analysis. Ask for and use them for this expertise.

What kind of data is expected? The specific tests and quantity of data available depend on the industry. Be aware of the relevant industry standards and their requirements; but, also be aware that these standards are “least common denominators.” Simply because a part meets a standard doesn't guarantee it will be reliable in each application. The same part may have very different probabilities of failure under different use conditions. At a minimum, expect data on the component life at defined environmental and design conditions (specifications). What data can be requested? Plenty! Surprisingly few customers ask for data that is not volunteered but is often readily available. Ask for any quality and reliability data available for the parts of interest. When and how frequently should data be reviewed? Reliability data should be reviewed at initial part selection; when a part, process, or product changes; when a problem or failure occurs; and on a routine schedule for parts identified as critical to quality (CTQ) or performance. Who performs the testing and analysis? Analyses may be supplier performed, user performed (acceptance‐based testing), and/or performed by a third party or independent laboratory. Users should have CTQ suppliers under a scorecard process and should make reliability and quality data part of the supplier‐selection and ‐monitoring process.

Areas to consider for supplier data and supplier performance monitoring include:

 Statistical process control (SPC) report data

 Outputs from a Continuous Improvement (CI) system

 Abnormal lot control data

 Process change notification (PCN) for all changes

 Process change approval (PCA) on all major changes (custom‐designed parts)

 Yield and in‐line monitor data

 Facility audit results

 ISO 9001 certification (or other relevant certifications or standards)

 Reliability monitor program data

 Storage and handling data

For silicon die and packaging, examples of reliability data that may be available include data retention bake (DRB), electrostatic discharge (ESD), endurance test (END), HAST, high‐temperature operating life test (HTOL), latch up (LU), steam pressure pot (SPP), and temperature cycle (TC).