What’s SON Package?
Small-outline no-lead package (SON), also known as Flat no-leads, and micro leadframe (MLF).
Flat no-leads packages, such as quad-flat no-leads (QFN) and dual-flat no-leads (DFN) physically and electrically connect integrated circuits to printed circuit boards (PCBs). Flat no-leads is a surface-mount technology (SMT), one of several package technologies that connect ICs to the surface of circuit boards without through-holes. Flat no-lead is near chip scale plastic encapsulated package made with a planar copper lead frame substrate. Perimeter lands on the package bottom provide electrical connections to the PCB. Flat no-lead packages include an exposed thermally conductive pad to improve heat transfer out of the IC (into the PCB). Heat transfer can be further facilitated by metal vias in the thermal pad. The QFN package is similar to the quad-flat package (QFP), and a ball grid array (BGA).
Small-Outline No-Lead Package (SON)
Variants
Different chip manufacturers use different names for this package: ML (micro-leadframe) versus FN (flat no-lead), in addition there are versions with pads on all four sides (quad) and pads on just two sides (dual), thickness varying between 0.9-1.0mm for normal packages and 0.4mm for extremely thin. Abbreviations include:
| Package | Manufacturer | |
| DFN | dual flat no-lead package | Atmel |
| DQFN | dual quad flat no-lead package | Atmel |
| cDFN | iC-Haus | |
| TDFN | thin dual flat no-lead package | |
| UTDFN | ultra-thin dual flat no-lead package | |
| XDFN | extremely thin dual flat no-lead package | |
| QFN | quad flat no-lead package | Amkor Technology |
| QFN-TEP | quad flat no-lead package with top-exposed pad | |
| TQFN | thin quad flat no-lead package | |
| LLP | leadless leadframe package | National Semiconductor |
| LPCC | leadless plastic chip carrier | ASAT Holdings |
| MLF | micro-leadframe | Amkor Technology and Atmel |
| MLPD | micro-leadframe package dual | |
| MLPM | micro-leadframe package micro | |
| MLPQ | micro-leadframe package quad | |
| DRMLF | dual-row micro-leadframe package | Amkor Technology |
| VQFN/WQFN | very thin quad flat no-lead | Texas Instruments and others (such as Atmel) |
| UDFN | ultra dual flat no-lead | Microchip Technology |
| UQFN | ultrathin quad flat no-lead | Texas Instruments and Microchip Technology |