Vias & Contacts doubled

[gafsos]

Why Vias & Contacts should be doubled in design ?

Thanks

 

[jeevan.life]

More vias and contacts are preferred to reduce the resistance offered to current flow......suppose u put 2 vias they act like 2 resistors in parallel and so on..

 

[dgnani]

Why Vias & Contacts should be doubled in design ?

Thanks

Using redundant vias is mostly done for yield in digital designs even though it can have an impact on timing too. In analog design besides yield you have -as mentioned already- paths that can be sensitive to parasitic resistance, so you use it there too

 

[dick_freebird]

Every contact / via has a probabilistic yield. Suppose your 1K
contact chain yield is 99%. That's 1% chance of bad circuit
per 1K vias. If you are doing big digital and you have 100K
vias, that's not looking good.

Your odds of having two vias out of the pair being bad, is
square-law lower. Like 1% per million vias.

Ecen scarier is processes where vias have an incidence of
partial fill, which can be a reliability problem. Redundancy
gives you a "backup plan".