| |
That quality assurance function at Forza Silicon ensures that products and services are reviewed after completion to determine the degree of excellence that was accomplished. Follow-up for improvement of deficiencies and corrections produces better quality products and services in the future. The following figure depicts Forza Silicon’s quality assurance system.
Before starting a proposal, it is essential to conduct customer interviews to ascertain the intended applications, the product quality and reliability required. Forza Silicon provides customers with an understanding of technical trends in the general marketplace, basic specifications, delivery periods, prices, quality, reliability and other demands on products. Information on demanded quality and reliability acquired through the above activities and accumulated experience on quality and reliability results from other projects, are used to set target quality and reliability levels which are appropriate to formulate design specifications.
Product design is an extremely important process for ensuring high reliability in semiconductor devices, and it is necessary to build in both quality and reliability.
At Forza Silicon, product design incorporates reliability in all aspects based on design specifications which have been thoroughly investigated in the proposal and specification stage. For example, circuit and layout designs have sufficient design flexibility to tolerate variances in the manufacturing process.
Product design work proceeds according to the design specifications. These design specifications include design inputs (customer demands, standards, in-house intellectual property, etc.) to ensure that appropriate requirements are selected. Product design passes through the stages of logic/circuit design, layout design, mask design, prototype manufacture and evaluation before reaching completion. In addition, reliability evaluation to assure quality and reliability levels, design review and design verification are carried out at strategic points throughout this process to confirm that the design input requirements are satisfied.
Design reviews consist of reviewing design results with the aim of improving design quality. Design verification checks that products meet needs and customer requirements using input documents (design specifications), output documents (evaluation data), related reports and other materials. In addition, production drawings and preparations are checked, products are approved as mass production types, and procedures for starting mass production are initiated.
A preliminary design review ensures that the architecture and mixed signal design observe and comply with the target specifications. Any enhancements or defects detected may be fed back into the architecture, design and/or specifications to improve product quality.
A critical design review ensures that the development done on the almost completed products complies with the specifications, quality and reliability needs of the customer. Product schematics, layouts, simulation results and functionality are inspected for detects and identification of high risk items. Observance of design standards is checked using various simulation tools during circuit and layout design, and the design results are automatically and manually verified against the design standards to check whether there are any design errors, design standard violations or problems with product performance.
In addition, internal reviews are conducted frequently by principal/senior engineers throughout the design and development stage. These reviews aim to avoid trouble after prototype manufacture and mass production, and build the target performance, quality and reliability into products in line with customer demands.
The reliability of prototypes is evaluated mainly through accelerated life tests, and the quality is certified in order assure the quality of semiconductor products. Based on the concept of building in quality in the manufacturing process, Forza Silicon works with the foundry to characterize products to establish upper and lower limits to be used as control metrics in the mass production of the chip.
Periodic quality meetings are held with foundry manufacturers, and quality improvement activities are promoted. These activities include extracting themes such as trend control for process control items and inspection passing rates, and correction and prevention of problems.
When trouble occurs in the manufacturing process, a trouble case is opened to capture diagnostic information, and track progress. Forza Silicon engineers work with the foundry and customer to investigate the root cause, formulate corrective actions and/or enhancements to correct the problem and prevent recurrence.
© 2007 All rights reserved.
|
