How to get directly the kernel file after building

Hi, I'm a fresh man about developing OpenWrt.

Every time I built a new image, I have to write it a SD card and then read the kernel file back from the first partition of the SD card. In fact I don't need the card to run my device, I can load the kernel by means of TFTP/NFS.

So, is there a way I can get the kernel file directly in the building tree?

I guess it be some where in the tree, but I don't know.