Electronics product design and life cycle
Design is a set of specifications for manufacturing
- Predictable
- Accurate
- Repeatable
- Flexible
- Maintainable
- Extensible
Fabrication complexity increase the importance of product design
Semiconductor complexity continues to increase
- Design errors
- Process steps
- Lithography resolution
- Difficulty of yield forecasting
- Lock in relationships to fabrication facility
Complexity of electronic devices continues to increase
- Use of embedded electronics
- Importance of device user interfaces
- Importance of life cycle design approaches
- Evolution of electronics supply chain
Image source: International Roadmap for Semiconductors. ITRS press conference, Dec 2004, 25.
Sources of new designs
- New purposes
- Observations
- Product defects
- Experiences
- Other designs
- New materials
- New technology
- New manufacturing processes
Purposes of design prototyping
- Visual representation
- Study processing techniques
- Study design possibilities
- Study cross-scale coupling of systems that span size scales of several orders of magnitude.
- Function
- Form
- Flow
- Physics
- Fabrication
Types of design prototyping
- Focused
- Comprehensive
Design tolerance is the difference between upper and lower limits of a dimension
- Components in product may have different tolerances.
- Tolerance is relative to size of component or product.
There are different types of tolerance levels
- Materials
- Tools
- Assembly
Why do we need tolerances for manufacturing?
Does tolerance affect cost of product?
Is it better to have smaller tolerances?
Design principle: Maintain independence of functional requirements
- Modular design
- More choice of materials
- More choice of processing
- Reduce critical failures
- Easier upgrades
- Easier maintenance
- More functional options
Image copyright Bose Inc.
Design principle: Minimize information content of the design
- Mass market
- Minimise errors
- Easier to sell
- Flexible for embedded use
Design principle: Delay product customization steps
- More flexibility for mass market
- Reduce response time for custom changes
- Reduce impact of changes in different markets
Image copyright Dell Computers
Design principle: Everything should be made as simple as possible, but not simpler
Quote attributed to Albert Einstein
- KISS – Keep it simple
- MISS – Make it simple
Design quality is fitness for purpose
- Functionality
- Performance
- Aesthetics
- Skill level
Image copyright Segway Inc.
Conflicts about purpose is often the primary cause of failed products!
Design quality is fitness for standards
- Based on inspection and measurement
- Six Sigma Quality
- ISO 9001:2000
Image copyright Princeton Digital Corp.
Measurement of quality is dependent on the purpose
- Time
- Functionality
- Material
- Process
- Cost
- Flexibility
Image copyright Acer Inc.
Design is fitness for market
- Satisfy user needs
- Industry structure and organizations
- Comparative cost
- Satisfy latent needs
Image copyright Sony Corp.
Design is the source of quality
Image copyright Dalsa Corp.
Product design must factor an increasing number of requirements (concurrent engineering)
- Use standard commercially available components
- Use common parts where possible
- Design for ease of component fabrication
- Design components with tolerances that are within process capability
- Design the product to be foolproof during assembly
- Minimise flexible components
- Design for ease of assembly
- Design for ease of packaging
- Minimise adjustments/calibrations
Design and quality are affected by many factors
- Delivery
- Installation
- Reliability
- Maintainability
- Serviceability
- Human factors
- Upgradeability
- Disposability
Design for assembly (DFA)
- Minimize parts count
- Encourage modular assembly
- Stack assemblies
- Eliminate adjustments
- Eliminate cables
- Use self-fastening parts
- Use self-locating parts
- Eliminate reorientation
- Facilitate parts handling
- Specify standard parts
Methods to manage the quality of manufacturing
Quality control
- Traceability
- Control of components
- Control of processing
- Points of inspection
- Assembly
Quality indicators
- Variables
- Measurable
- Tolerances
- Attributes
- Yes or no
Sampling methods
- 100% inspection
- Statistical sampling
Yield is quotient of good outputs to total outputs
- Yield is critical for electronics manufacturing
- Yield loss is due to systematic and random factors
- Manufacturing is a statistical business, yield management is about reduction of loss
The cost of quality
Source: Gallien, J. (2002). Lecture for 15.760B course. MIT.
Product disposal choices
Design for the environment
Design for the environment requires consideration of the complete product life cycle:
- conception and design
- prototyping
- manufacturing
- sales
- consumption
- end of use
Design for the environment is affected by changes and feedback from society about:
- input resources
- fit for purpose
- standards
