backlinks using widget code?

Hello guys!
I am really interested to create my own website widget. so the code will be

<a href="xyz.com"><img src="xyz.png"></a>

Code (markup):

Now my point is, how we can target a specific keyword in such type of "logo widget"?
because

 <a href="xyz.com"><img src="xyz.png">xyz</a>

Code (markup):

it's not the solution!
and will this work for getting back links that gonna indexed by google?

 

back link is depend on the char text

 

 <a href="xyz.com"><img src="xyz.png"[B] alt="[COLOR="red"]logo widget[/COLOR]"[/B]>xyz</a>

Code (markup):

 

yes i agree backlink depend upon char text

 

<a title="xyz" href="xyz.com"><img src="xyz.png" alt="logo widget">xyz</a>

Code (markup):

 

Apart from insert alt text like above ones recommended. I would recommend you surround those text with images related to your theme. This could help search engine bots understand more about your image link instead of just alt text attached.

 

guys! just remember I am not interested to use that "xyz" as keyword because when you add image the image with text never looks good! So I need to know if there any way to insert keyword inside the code !

 

alt is not a text link, but it's better than nothing...