solr string field

[ZAROGKIKAS,GIORGOS]

Hi 
        I use a string Field in my solr schema 
        but when I query a value with space it doesn't give me results
        
        e.g I have a value "sony vaio" when I query with "sony vaio" I
get 0 results
        but when I query "sony*" I get my results

        how can I query a string field with a space between the values 
        or how can I have exact search in a string 


Thanks in advance