What is the difference between TQFP and LQFP encapsulation?

The thickness of LQFP is 1.4 mm, and that of TQFP is 1.0 mm..

2, the size is not the same:

TQFP series supports a wide range of chip sizes from 7mm to 28mm, and LQFP size is smaller.

3. The number of sales leads is different:

The number of TQFP leads varies from 32 to 256, and the number of LQFP leads is generally above 100.

Extended data:

Advantages and disadvantages of TQFP package and its countermeasures

More than 90% of the integrated circuits in the world are packaged in plastic. The advantages of plastic packaging instead of airtight packaging are low cost, high assembly density, light weight, good operability and high work efficiency.

However, the poor waterproof performance of polymer materials such as epoxy resin in plastic packaging materials has always been one of the main reasons that affect the reliability of devices. After water vapor enters the package, it is easy to condense at the interface of different materials.

The combination of condensed water vapor with ions and impurities will lead to corrosion and short circuit, and in the reflow soldering process of surface mount technology, the package will crack in layers due to thermal expansion, which will eventually lead to device failure. With the development of electronic devices to high density and miniaturization, the influence of water vapor on plastic packaging devices is increasing, which gradually attracts research interest at home and abroad.

Water vapor content is the main reason for delamination cracking of devices; The interface between silver paste and plastic packaging material, chip pad and plastic packaging material is the weak link of TQFP device, and the delamination phenomenon is generated and expanded by these parts. PECVD SiNx thin films can effectively reduce the water vapor content in TQFP devices, and to some extent, eliminate cracking and delamination. The thicker the film, the better the waterproof effect, and the more obvious the effect of eliminating cracking and delamination.

Baidu encyclopedia -LQFP

Baidu encyclopedia -TQFP package