IC on Breadboard: I have a PCB IC (LTC3115), how to search if it's available for breadboard use?
how to check if the component is available on a breadboard? 


Check the manufacturer's web site. The answer is "no"; this part is only available in surface-mount packages.

Switching power supply designs tend to be highly sensitive to layout. We may be able to provide advice if you can show us the design you're using.