NiPd Finishes for Pb-Free Leaded Components

 

Donald C. Abbott

Texas Instruments

Attleboro, MA

 

d-abbott1@ti.com

 

 

Abstract:

 

Lead (Pb)-free electronics present two primary challenges to IC manufacturers. First, eliminate Pb from the IC package and second, develop ICs that will withstand the rigors of reflow at up to 260C. This talk will concentrate on the first challenge.

 

Nickel-palladium (NiPd) based lead finishes have been in commercial use since 1989, with more the 50B devices now in the field from one semiconductor house alone. The NiPd finish has recently been modified to a nickel-palladium-gold finish. These are preplated (PPF) leadframe finishes, that eliminates the need for plating after assembly/encapsulation. The structure and features of both Pd based finishes will be discussed.

 

That NiPd based finishes have not become more prevalent in the industry is a conundrum. There are advantages to any type of preplated leadframe that are obvious. There are some advantages to Pd based finishes that are less obvious. The disadvantages and risks, real and perceived, associated with NiPd based finishes will also be covered.