Reliability Issues Mohammad Sharifkhani Reading Textbook I Chapter
Reliability Issues Mohammad Sharifkhani
Reading • Textbook I Chapter 18 • Textbook I Chapter 20 • The paper on SER
Motivation • There is a long distance from a chip working in a lab to a chip working in the field • Reliability • Robustness • Fatigue • Many of the culprits are in rise as technology scales
Introduction • • Packaging Electromigration ESD Protection SER Protection
Chip Packaging • Bond wires (~25 m) are used to connect the package to the chip • Pads are arranged in a frame around the chip • Pads are relatively large (~100 m in 0. 25 m technology), with large pitch (100 m) • Many chips areas are ‘pad limited’
Pad Frame Layout Die Photo
Chip Packaging • An alternative is ‘flip-chip’: – – Pads are distributed around the chip The soldering balls are placed on pads The chip is ‘flipped’ onto the package Can have many more pads
Tristate Buffers V DD En Out In En Increased output drive Out = In. En + Z. En
Electromigration • Current density (current per unit area) • A reliability issue creates problem over time – Due to transport of metal ions – AC signals will be fine • Breaking or shorting to adjacent wire • Keeping current below 0. 5 to 1 m. A/um relaxes the problem – For DC wires (power/GND) • IR Drop transient problem (peak current) • Electromigration DC problem (ave. current) • Using copper helps
Electromigration (1)
Electromigration (2)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD) Which one fails?
Electro-Static Discharge (ESD) Second breakdown of the path at a higher voltage level than the second breakdown of the ESD path Second breakdown of the path at a lower voltage than the second breakdown of the ESD path
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD) There are challenges as technology scales!
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD) Design of ESD protection circuits: A glimpse!
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD)
Electro-Static Discharge (ESD) • ESD protection is extremely important when dealing with high speed input output signals • I/O Capacitance
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
Soft Error
- Slides: 64
