Acting as the 'Final Guardian' of Quality with Data… The Core of SK hynix Quality Assurance Roles

The specific roles of the 'Quality Assurance (QRA)' position, which is responsible for the perfection of products throughout the entire process from design and development to mass production and final delivery to customers, have been revealed. This role, as shared by SK hynix, goes beyond simply filtering out defective products; its ultimate goal is to ensure product reliability and supply products of the desired quality at the time requested by customers.

A 'Commander' managing the entire life cycle, from product certification to mass production quality

QRA, SK hynix's quality assurance organization, stands for Quality, Reliability, and Assurance, and is overall responsible for the reliability and guarantee of products. The role is largely divided into 'Product Certification,' which provides final approval so that products can go out into the world, and 'Mass Production Quality,' which analyzes process changes occurring during mass production to pre-determine risks at the time of customer shipment.

Mass production quality engineers monitor process changes based on products that have transitioned from the development stage to mass production. In particular, due to the nature of the process where hundreds of thousands of wafers and tens of millions of data points are generated, it is impossible to judge every single product individually, so they perform their duties based on Statistical Process Control (SPC). If a trend deviation occurs that falls outside the statistical Control Limit, they manage quality by discarding materials or adjusting the mass production flow through appropriate measures.

Data-based persuasiveness and expertise as an 'all-rounder'

The quality assurance role involves very frequent collaboration with related departments. They discuss improvement measures for quality enhancement with development and mass production departments, and communicate with customers regarding quality activities and product promotions. In particular, since the quality assurance role often has to express opinions that conflict with productivity or manufacturing capabilities, strong persuasiveness to convince other departments is required.

The key in this case is 'data.' Only by presenting objective quality data, rather than emotions or experience, can they draw cooperation from other departments. Furthermore, since products go through the entire process from design, development, and manufacturing to shipment, 'all-rounder' knowledge that encompasses the whole, rather than being buried in a specific field, is necessary. This is because they must understand various processes, such as design or mass production technology, to make accurate judgments when quality issues arise.

From extreme environment testing to space semiconductor verification

In the quality assurance process, harsh tests are conducted to confirm whether semiconductors can withstand actual usage environments. To simulate the process of attaching balls on the back of the semiconductor to a substrate, a reflow test is performed by raising the temperature up to 260 degrees Celsius, and the limits are verified by applying impact to the product or exposing it to low-temperature/high-humidity environments.

Recently, quality verification work is also being conducted for semiconductors that must operate in space environments, which have much harsher temperature and humidity conditions than the usage environments of existing customers. The quality assurance role prioritizes quality as the number one priority while also considering productivity indicators such as yield to find the optimal point.

Source: original video (YouTube)