QFN (QUAD FLAT No-Leads Package) is a kind of non-pitch package, which is square or rectangular. There is a large-scale naked pad in the center of the packaging at the bottom of the packaging.Conductive pad
Because QFN packaging does not have gull -wing -like leads like the traditional SOIC and TSOP packaging, the conductivity path between the internal pins and the pads is short, the self -sense coefficient and the wiring resistance in the packaging body are very low, so it can provide excellent electrical properties.In addition, it also provides excellent heat dissipation performance through the exposed lead frame pad. The pad has a direct cooling channel to release the heat in the package.
The heat dissipation pad is usually welded directly on the circuit board, and the heat dissipation of the PCB can help spread the excess power consumption to the copper connecting floor, thereby absorbing excess heat.
◆ Two advantages of QFN packaging
Physical aspect: small volume, light weight
QFN has a very prominent feature, that is, QFN packaging has the same external configuration as the ultra -thin small -shaped packaging (TSSOP), but its size is 62%smaller than TSSOP.QFN packaging is small and light in weight. This packaging is particularly suitable for any size, weight and performanceApplications required.Nowadays, electronic products have a clear trend, that is, it continues to develop towards a smaller volume and lighter weight. Among them, the packaging volume of the chip also basically reflects the weight of the chip.
In terms of quality: good heat dissipation, good electrical performance
QFN packaging has good thermal performance, because the bottom of the QFN package has a large area of heat dissipation pads, which can be used to convey the heat generated by the chip work in the packaging body.The corresponding heat dissipation pads and heat dissipation pores, the heat dissipation pads provides a reliable welding area, and the perforated provides the heat dissipation pathway; the PCB heat dissipation hole can spread the excess power consumption to the copper connection floor to absorb excess heat, which is extremely extremeGreatly enhances the heat dissipation of the chip.
◆ QFN(quad flat non-leaded package)
There is no flat packaging on all sides, one of the packaging packages on the surface。Most of them are now called LCC.QFN is the name stipulated by the Japanese Electronic Machinery Industry Association.
There are electrode contacts on the right side of the packaging. Because there is no pitch, the possession has a smaller area than QFP and the height is lower than QFP.The electrode contact is difficult to achieve the pins of QFP, generally from 14 to 100.There are two types of materials: ceramics and plastic.
