Quality Assurance - Hitachi AP1 Data Book

QUALITY ASSURANCE
1. VIEWS ON QUALITY AND RELIABILITY
deSign, device design, layout design, etc. There-
fore, as long as standardized proceSSing and
Basic views on quality at Hitachi are to meet the materials are used the reliability risk is extremely
individual uers' required quality level and maintain a small even in the case of new development
general quality level equal to or above that of the devices, with the exception of special require-
general market. The quality required,by the user may ments imposed by functional needs.
be specified by contract, or may be indefinite. In either
case, efforts are made to assure reliable performance
in actual operating circumstances. Quality control
during the manufacturing process, and quality aware-
ness from design through production lead to product
quality and customer satisfaction. Our quality assur-
ance technique consists basically of the following
steps:
(1) Build in reliability at the design stage of new
product development.
(2) Build in quality at all steps in the manufacturing
process.
(3) Execute stringent inspection and reliability con-
firmation of final products.
(4) Enhance quality levels through field data feed
back.
(5) Cooperate with research laboratories for higher
quality and reliability.
With the views and methods mentioned above,
utmost efforts are made to meet users' requirements.
2.
RELIABILITY DESIGN OF
SEMICONDUCTOR DEVICES
2.1 Reliability Targets
The reliability target is an important factor in sales,
manufacturing, performance, and price. It is not ade-
quate to set a reliability target based on a single set of
common test conditions. The reliability target is set
based on many factors:
(1) End use of semiconductor device.
(2) End use of equipment in which device is used.
(3) Device manufacturing process.
(4) End user manufacturing techniques.
(5) Quality control and screening test methods.
(6) Reliability target of system.
2.2 Reliability Design
The following steps are taken to meet the reliability
targets:
(1) Design Standardization
As for design rules, critical items pertaining to
quality and reliability are always studied at circuit
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(2) Device Design
It is important for the device deSign to consider
total balance of process, structure, circuit, and
layout design, especially in the case where new
processes and/or new materials are employed.
Rigorous teChnical studies are conducted prior to
device development.
(3) Reliability Evaluation by Functional Test
Functional Testing is a useful method for design
and process reliability evaluation of IC's and LSI
devices which have complicated functions.
The objectives of Functional Test are:
• Determining the fundamental failure mode.
• Analysis of relation between failure mode and
manufacturing process.
• AnalysiS of failure mechanism.
• Establishment of QC points in manufacturing
process.
2.3 Design Review
Design Review is an organized method to confirm that
a design satisfies the performance required and
meets design specifications. In addition, design review
helps to insure quality and reliability of the finished
products. At Hitachi, design review is performed from
the planning stage to production for new products,
and also for design changes on existing products.
Items discussed and considered at design review are:
(1) Description of the products based on design
documents.
(2) From the standpoint of each participant, design
documents are studied, and for points needing
clarification, further investigation will be carried
out.
(3) Specify quality control and test methods based on
design documents and drawings.
(4) Check process and ability of manufacturing line to
achieve design goal.
(5) Preparation for production.
(6) Planning and execution of sub-programs for
design changes proposed by individual specialists,