Generally speaking criminal records are not automatically expunged in Pennsylvania. There are certain limited instances in that regard. It would depend on the county involved. An ARD case may be automatically expunged but most often that is not the case. It's important to know whether your case would of course be automatically expunged or not but the general expectation is that it would not be automatically expunged.
Expungement is different than a record sealing, though. Due to the passage of Pennsylvania's clean slate law and related laws, certain cases and offenses are eligible for an automatic sealing that is different from an expungement. Whereas an expungement destroys the records per Pennsylvania law and the FBI would also be served with the expungement order per the Pennsylvania State Police and the FBI would generally, while they're not bound by Pennsylvania law, would generally do what they could to clean up a person's record as best as possible.
In automatic record sealing the records do not get destroyed. They're still maintained, although they are sealed, meaning that they would still be available to certain law enforcement and government agencies upon request including professional licensing boards. It's important to know if your case would be automatically expunged or not and then if it is eligible for an expungement, even if it is automatically sealed, a person would definitely be best served by having their case expunged in addition. An experienced Pennsylvania criminal defense attorney will help you understand what your options are and would be best to address your case so that you could get your record cleaned up.
