Logic devices 100% lead-free

Texas Instruments has announced that its complete logic portfolio is now offered in Pb-free solutions for all finishes and balls.

Nickel palladium gold (NIPdAu) has been chosen as the Pb-free finish for all leadframe-based package due to its compatibility with Pb-free solders and tin (Sn) whisker growth.

NiPdAu finish is solderable with both SnPb and the industry standard Pb-free solder alloy, SnAgCu, making it backward and forward compatible. This compatibility with both current and future solders made it possible to use NiPdAu finish components during and after the industry transition to Pb-free.

A second concern in selection of lead-free finish is whisker growth. Sn whiskers may grow and eventually short metal surfaces or break off within a finished assembly. TI's claims the NiPdAu finish was chosen to eliminate the possibility of Sn whiskers.

Moisture sensitivity performance of IC packages is a user concern because of the potential for "popcorning" and delaminating caused by expansion of moisture trapped inside the plastic during reflow. The higher melting point of Pb-free SnAgCu solder alloys compared with SnPb demands higher peak reflow temperature in Pb-free soldering processes. Thus, component suppliers will be required to classify their components for moisture sensitivity performance at lead-free processing temperatures. In some cases this will mean implementing advanced material sets capable of being used in the higher-temperature processes.

All TI logic packages are now classified per J-STD-020B (Max Reflow temp of 250 degrees C) Pb-free parameters.