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.
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 |
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
10 Reading from SEA1200VX
Sn-Ag(µm) | Pb(ppm) | |
---|---|---|
Ave. | 5.5 | 348 |
STDEV | 0.02 | 8.95 |
CV% | 0.27 | 2.57 |