24.Design For Manufacturing

DFM Guidelines

􀂾 Use standard components
􀂾 Minimize number of parts
􀂾 Develop modular, multi-functional, multi-use designs
􀂾 Consider tolerance for variations in process (portability)
􀂾 Keep in mind current process capability
􀂾 Design for ease of handling
􀂾 Recognize design testability is a requirement for manufacturability
􀂾 Involve the manufacturing team in each of the above

Metrics for DFM

􀂾 Time to Market (Right First Time is ideal)
􀂾 Number of Iterations between design and manufacturing teams until they “get it right”
􀂾 Lead time
“The product [design] community should be measured on how manufacturable the design is. The metrics should be on the manufacturing floor.”– Chip McDaniels, Ford.

DFM Examples

􀂾 In the design of microelectronics, memories tend to have manufacturing defects which affect yields. A DFM oversightcan lower the yield of the chip critically. If designers would have had manufacturing in mind, they could have included a suitable amount of redundancy to cover for the defects. Every redesign/workaround could cost the company over $1M and 12 weeks turnaround.

􀂾 In the design of complex communication modules at HRL Laboratories, regular meetings are scheduled between design and manufacturing (process) engineers to hash out the capability in the clean room and make sure designers do not send impossible masks to the clean room for production. It is not unusual to have up to 8 formal and informal meetings with the process engineers through a 10 week design cycle!