Lead finish composition & Tin plating process

This page includes information about lead finish and solder?ball composition options that TI offers.?Additionally, information about TI’s Tin plating process is detailed?below.?

Lead finish composition

For device-specific composition, click?here.

Option	Composition
Standard	85% SN, 15% Pb
Standard	63% SN, 37% Pb (some Metal Can packages)
Pb-Free	Matte Sn
	NiPdAu
	NiPdAuAg
	SnCu
	SnAgCu
	Au over Ni

Solder ball composition

For device-specific composition, click here.

Option	Composition
Standard	SnPb
Pb-Free	SnAgCu
Pb-Free	SnAg

Tin plating process

TI’s Tin plate process meets and/or exceeds qualification and monitoring standards set in JESD201, with Class 1 and Class 2 levels inspection per JESD 22A121. In addition, TI has taken the following actions for Tin plating products to meet JESD201 Class 2 requirement:

Leadframe base material (alloy) control
Tin plating control (chemistry, process and thickness)
Post-plate annealing (150C minimum within 24 hours of plating)

TI uses leadframe materials such as Cu194, Cu7025, EFTEC-64T, TAMAC2, and TAMAC4.

Tin whiskers

Tin whiskers occur due to stresses in the plating process and are known to occur on tin plated or tin-alloy plated parts.
Tin whiskers growth creates a reliability concern due to the fact that they may bridge the gap between leads causing electrical shorting.
As a whisker mitigation measure, TI
- Anneals Matte Sn post plated leadframe-based packages with formed leads for 1 hour at 150° C within 24 hours of plating. This is the industry-accepted method for controlling whisker growth.
- Maintains the minimum “as plated” thickness is 7 μm, with 15% of thinning allowed after lead trim and form for electro-Plated devices. This thickness conforms to the recognized Tin Whisker Mitigation practices published in JEDEC/IPC JP002.
- Dips SnAgCu alloy to a minimum thickness of 5 μm after lead trim and form for Hot Solder Dipped devices. This process is considered "Whisker free" per JEDEC/IPC JP002.

Representative whisker test results per JESD201

Leadframe Material (Alloy)		C19400 (Cu194)			C07025 (Cu7025)			C18045?(EFTEC-64T)			TAMAC 2			TAMAC 4
Stress Test	Timepoint	Precondition A	Precondition C	Precondition D	Precondition A	Precondition C	Precondition D	Precondition A	Precondition C	Precondition D	Precondition A	Precondition C	Precondition D	Precondition A	Precondition C	Precondition D
Temperature Cycling?(-55C/ +85C) or (-40C/ +85C)	1500 cycles	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm	<45 μm
High?Temperature /?Humidity?Storage (55C/85%RH)	4000 hours	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm	<40 μm
Temperature /?Humidity?Storage (30C/60%RH)	4000 hours	no precondition	<40 μm	<40 μm	no precondition	<40 μm	<40 μm	no precondition	<40 μm	<40 μm	no precondition	<40 μm	<40 μm	no precondition	<40 μ---m	<40 μm