1.  Field of the Invention
The present invention generally relates to a package structure and a manufacturing process thereof.  More particularly, the present invention relates to a leadframe package structure and a manufacturing process thereof. 
2.  Description of Related Art
For continuous growth in the RF/wireless, portable applications and PC peripheral markets, higher performance and increased I/O counts in a smaller package has have been greatly demanded.  Advanced leadframe packaging, including quad flat no lead (QFN) packages and enhanced leadless leadframe-based packages, has become widely accepted and is suitable for the chip package with high-frequency (for example, radio frequency bandwidth) transmission. 
Increasing demand for the advanced leadframe package structures prompts the industry to look for more efficient packaging methods.  Moreover, as the number of I/O pads keeps increasing, the advanced leadframe package structures need to promote the electrical performances and product reliability.