Quality and Reliability Assurance / Handling Precautions
030901
QUA-1
2002-02-20
Quality And Reliability Assurance / Handling Precautions
In recent years, technical revolutions have become almost a daily occurrence in the
electronics industry. This is accompanied by the increasing application of semiconductors in
both the consumer and industrial sectors, and demands for higher quality and higher
reliability.
Toshiba is making every effort to improve both quality and reliability with the following
quality control system which incorporates product design, quality assurance for parts and
materials received, manufacturing process quality assurance, shipping quality and
reliability assurance, and quality after-service based on user demands and market survey
data.
1 Quality And Reliability Assurance
1.1 Quality Assurance
Trying to sense the customer's needs, we do our best to incorporate the quality and
reliability required by the customer into the design, while considering the safety
and PL (Product Liability) of the products.
Quality and reliability evaluation are performed on the developed products
according to the Toshiba's reliability test standard which is prepared in conformity
with JIS, EIAJ, MIL, etc., thereby certifying the design. The parts and materials
are standardized through the engineering department and the quality assurance
department. After the design is accepted, standardization is performed by the
engineering department on the parts and materials, process plan, and inspection
plan. Engineering Institution of Works (EW) is then established on the working
detail. The quality and reliability evaluation are performed on the mass-produced
products on an experimental basis.
In the mass production, the production department has control of the
manufacturing process, the environment and facility, and the quality assurance
department. Quality assurance performs incoming inspection of parts and
materials, modification control, instrument control, periodical reliability test and
line audit. The production technology divisions also participate in process
improvement, automatization, etc.
Education and training for quality and reliability, are given to new workers,
inspectors, engineers and small groups (QC/ZD movement). In shipping the
finished products, a lot quality assurance test is performed by the quality assurance
department. We then commence preparation of specifications meeting pre-arranged
quality and reliability standards and the inspection and reports on discrepant
products "quick action" as the motto. Figure 1 shows the quality assurance system
of semiconductor.
Quality and Reliability Assurance / Handling Precautions
030901
QUA-2
2002-02-20
1.2 Quality Assurance Level of Semiconductor Products
Table 1 Lot Quality Assurance (AQL display: in accordance with ANSI Z 1.4-1993)
Item
AQL
0.15%
0.15%
0.25%
Appearance
Serious Defect
Minor Defect
Electrical Characteristics
Table 1 shows the lot quality
assurance level, which is complied
with the sampling inspection
method (AGL) of MIL-STD-105E.
Quality and Reliability Assurance / Handling Precautions
030901
QUA-3
2002-02-20
Department
Market /
Application
Manufacturing
Production
Control System
Step
Customers
Engineering
Engineering
Control
DR/AT
Check Sheets
Meetings
Planning
Development CS
Development
Planning
Meeting
Development
Design
DR
DAT
Development CS
DAT Execution
Plan CS
Design Planning
Meeting
DAT Execution
Meeting
Trial Run
Production
QAT
QAT Execution
Plan CS
DAT Execution
Meeting
QAT Execution
Meeting
QAT Review
Meeting
Transfer
Meeting
Full
Production
PAT
PAT Execution
Plan CS
PAT Execution
Meeting
PAT Review
Meeting
Review of
Specifications
Parts and
Materials
Approval
Qualification
of Parts and
Materials
Confirmation
of Shipped
Quality
Trial Production of Developed Product,
Evaluation of Characteristics
Approval of Production
Quality
Complaint
Handling
Failure
Analysis
Approval of Production
Product
Q & R Evaluation of
Production Product
Transfer to Full Production
*3
*4
*2
*1
QA Meeting
Control of Changes
Full Production
Q & R Evaluation of Trial Run Production
Subcontracting
Trial Run
Production
Standardization (Parts & Materials,
Process Plan, Inspection Plan)
Determine Specification
Product Design
Determine Development Plan
Design Approval
Q & R Evaluation of Developed Product
Design Review, Safety and PL Check
Market Research
Preparation
of Engineering
Instructions
Quality, Engineering and Complaint
Service
Shipment
Complaint
Delivery
Subcontractors
Manufacturing
QA
Marketing
DR:
Design Review
*1
Improvement of Manufacturing Technology
DAT: Design Approval Test
Promotion of Automatization
QAT: Quality Approval Test
*2
Inspection of Incoming Parts
CS:
Check Sheet
Line Audit
Reliability Test
Measurement Control
Quality Training & Education
*3
Manufacturing Control
Environmental Control
Facility Control
Assurance of Quality, Cost & Delivery
*4
Control of Delivery and Quantity
Figure 1 Quality Assurance (QA) System of Procedural Flow
Quality and Reliability Assurance / Handling Precautions
030901
QUA-4
2002-02-20
1.3 Reliability of Microcontrollers
For microcontroller products, reliability can be estimated within the following
temperature range.
Tj = 0
C to 85C
Tj (junction temperature) can be calculated using the following formula:
Tj = Ta + Q
ja
Ta: Operating environment temperature for the product
[C]
The operating environment temperature is the temperature of the
surrounding environment. The thermal effects of the operation of the
product are not taken into account.
Q: Average power consumption of the product
[W]
ja: Thermal resistance of the package [C / W]
Note 1: When operating the device outside the range Tj = 0
C to 85
C for
extended periods, please contact your nearest Toshiba office or
authorized Toshiba dealer.
Note 2: For details of the value of
ja, please contact your nearest Toshiba office
or authorized Toshiba dealer.
Quality and Reliability Assurance / Handling Precautions
030901
QUA-5
2002-02-20
2 Handling Precautions for Microcontrollers
2.1 Mounting Precautions
Plastics have basically porous feature. When a chip (especially an SMD which has a thin
plastic surface) is heated in a state of moisturized and is soldered by the reflow soldering
method, moisture is vaporized as the temperature rises to cause a package expanded. Or a
borderd surface between a lead frame and a plastic material is peeled off to cause a crack.
These bring serious troubles on reliability.
In order to prevent hygroscopity or enable high heat treatment after absorbing moisture,
Toshiba uses a dampproof packing and/or a heat proof tray.
(1)
Recommended Methods of Soldering for Flat Packages
Table 2.1 lists the recommended method of soldering flat packages. If you have
any question or request, please refer to "IC PACKAGE MANUAL" or contact
your local offices.
For overall heating method, recommended mounting methods and
conditions after opening the pack differ depending on products to be
used. See Table 2.2 and 2.3 for the details.
For locally heating a lead part, soldering iron method is
recommended. For other localized heating methods, refer to "IC
PACKAGE MANUAL" or contact your Toshiba local offices.
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