Different Types of QFNs
Two types of QFN packages are common: air-cavity QFNs, with an air cavity designed into the package, and plastic-moulded QFNs with air in the package minimized.
Less-expensive plastic-moulded QFNs usually limited to applications up to ~2–3 GHz. It is usually composed of just 2 parts, a plastic compound and copper lead frame, and does not come with a lid.
In contrast, the air-cavity QFN is usually made up of three parts; a copper leadframe, plastic-moulded body (open, and not sealed), and either a ceramic or plastic lid. It is usually more expensive due to its construction, and can be used for microwave applications up to 20–25 GHz.
QFN packages can have a single row of contacts or a double row of contacts.
Read more about this topic: Quad-flat No-leads Package
Famous quotes containing the word types:
“Our major universities are now stuck with an army of pedestrian, toadying careerists, Fifties types who wave around Sixties banners to conceal their record of ruthless, beaverlike tunneling to the top.”
—Camille Paglia (b. 1947)