Lead (Pb) in Thin Film Samples

We know that electroless nickel phosphorus plating and Pb-free solder plating contain small amounts of Pb that must be controlled as a hazardous element. Hitachi High-Tech Science developed the Thin Film FP method for accurate measurement of plating samples.

Measurement of Electro-less Ni Plating

The table and figure below shows excellent results of 10 readings of approximately 350ppm of Pb in Ni-P plating (5um) over cupper. The correlation of Pb is less than 3%. The readings correlate well with ICP values.

Measurement Conditions (SEA1200VX)
Method: Thin Film FP
Beam Size: φ8.0mm
Voltage: 50kV
Current: Auto
Atmosphere: Air
Primary Filter: For Pb

Sample
Electro-less Ni Plating 5µm

ICP Result
Pb 363ppm

10 Reading from SEA1200VX

	Ni-P(µm)	Pb(ppm)
Ave.	5.54	334
STDEV	0.26	8.66
CV%	4.68	2.59

Measurement of Pb Free Solder

Pb-free solder plating also contains a small amount of Pb. The table and figure below show excellent results from one reading of a Pb measurement in Pb-free solder plating 5 micro meters in thickness. The CV value of Pb concentration was less than 3% and the reading also correlates well with ICP.

Measurement Conditions (SEA1200VX)
Method: Thin Film FP
Beam Size: φ8.0mm
Voltage: 40kV, 50kV
Current: Auto
Atmosphere: Air
The Primary Filter: For Pb & For Cd

Sample
Pb in Pb Free Solder 5µm

ICP Result
Pb 312ppm