ca i have my 20 year old felony conviction from pennsylvania sealed/expunged?

I have lived in California for 20 years since my conviction and have become a very productive member of society. I have a Mastrers degree and I am a top tier Executive in the aerospace field. My name is on the internet regarding my arrest and having this info out there can ruin my life. I have a wife and a son who is a 4.0 student. To have this over my head when all parties/courts have been paid and that was the only time in my life that I was ever in trouble, isn't right. One mistake shouldn't ruin your life. I have made my familys life very good.