As an integrated device manufacturer (IDM), ST has vast internal technical competence in front end and back end manufacturing and associated quality. As a consequence, and in contrast to fabless companies, we are able to deeply engage with front end and back end subcontractors both to correct and to prevent all sorts of quality issues.
We use our technical competence to perform rigorous supplier quality audits for all categories of suppliers including
- Wafer foundries
- Assembly, test and finishing subcontractors
- Equipment suppliers
- Direct and indirect material suppliers
Each of our suppliers must formally endorse the ST quality strategy and associated policies in order to provide a level of quality that is equivalent to that of our own internal manufacturing. Suppliers are regularly evaluated through a scorecard, where quality performance weighs significantly.
SUPPLIER SELECTION PROCESS
When extra manufacturing capacity or new specialized materials or processes are requested, the process to select viable suppliers starts with a series of prerequisites, such as certification to international standards like ISO 9001 and alignment to ST requirements for quality, manufacturing capability, sustainability and specific requirements based on the industry domain. If a supplier fulfills these criteria, a detailed evaluation is performed before engaging in the final qualification, covering items such as:
- Maturity of the Quality Management System
- Compliance to the ST list of banned substances
- Specific machine and process capabilities
- Material specifications and control methods and limits
- Process control methods
These items are verified through site audits. The performance of each supplier is reassessed a minimum of once per year through a supplier control method, and a positive evaluation is required to reconfirm qualification.