please go to the Yorkshire Terrier Club of America, they have lists of different breeders in different states that they recommend as being safe and healthy Yorkie breeders.
Here's the link:
Yorkshire Terrier Club of America
I got my little guy from a woman in NY named Wendy Garcia. I've spoken with a lot of the breeders in NY, PA, and CT and while they can be pricey, it is so much better to find a healthy puppy from one of these responsible breeders
Good Luck