Abstract

Airborne and surface Pb concentrations were measured inside a glovebox chamber with controlled inflow rate at 1.0 L/min of ultrapure air over a 4-hour period while an operator completed 1,680 solder connections using Sn63:Pb37 solder with rosin flux core. Chamber atmosphere showed released mean Pb mass of 0.0238 ± 0.011 μg and mean airborne concentration of 0.176 ± 0.085 μg/m³. Of the total solder mass used in two trials, on average 4.65% was recovered from the tip cleaning sponge and 0.14% dropped onto the work surface, with a surface loading rate of 0.30–0.45 μg/cm². The estimated fingertip surface area in contact with solder wire was 14.7 cm², with a measured average Pb mass of 14.9 μg, and a corresponding dermal loading rate of 1.01 μg/cm². The waste solder dross surface area determined from digital micrographs in each trial were 1.65 and 2.43 cm², with corresponding Pb density of 714 and 610 mg/cm² and >90% of the detected dross mass comprising particles >100 μm in the widest dimension. Corresponding increases in blood Pb levels estimated using physiologically-based pharmacokinetic modeling were negligible compared with background. These findings demonstrate very low Pb emissions to air and surfaces during intensive manual microelectronic soldering activities.

摘要

在手套箱室内以4个小时的时间以1.0 L / min的超纯空气流量控制进风量来测量空气中的Pb浓度和表面Pb浓度，同时操作员使用带有松香助焊剂芯的Sn63：Pb37焊料完成了1,680个焊料连接。室内空气显示释放的平均Pb质量为0.0238±0.011μg，平均空气传播浓度为0.176±0.085μg/ m ³。在两次试验中使用的总焊料量中，平均4.65％的焊料是从吸头清洁海绵中回收的，而0.14％的焊料滴到了工作表面上，表面负载率为0.30–0.45μg/ cm ²。估计的与焊锡丝接触的指尖表面积为14.7 cm ²，测得的平均Pb质量为14.9μg，相应的皮肤负载率为1.01μg/ cm ²。在每个试验中，通过数字显微照片确定的废锡渣表面积为1.65和2.43 cm ²，相应的Pb密度为714和610 mg / cm ^2，并且检测到的锡渣质量的90％包括最大宽度上> 100μm的颗粒。与背景相比，使用基于生理学的药代动力学模型估算的血液中铅的相应增加可以忽略不计。这些发现表明，在密集的手动微电子焊接活动中，铅向空气和表面的排放极低。