Study of fluxless soldering using formic acid vapor

Author

Lin, Wei ; Lee, Y.C.

Author_Institution

Nokia Res. Center, Irving, TX, USA

Volume

22

Issue

4

fYear

1999

fDate

11/1/1999 12:00:00 AM

Firstpage

592

Lastpage

601

Abstract

This paper presents a systematic study of the use of formic acid vapor fluxless soldering with eutectic Pb/Sn solder. The study focused on the solder joint self-aligning process and the final alignment accuracy. The main effect considered was the formic acid vapor concentration. In addition, other effects of solder joint height and background vibration were studied. The self-alignment characteristics of the fluxless soldering process was as good as those using liquid flux at 220°C. 2 μm alignment accuracy could be achieved within 10 s. The most important parameter was the formic acid vapor concentration in the reflow chamber. The effective concentration window was found to be greater than 0.7% in volume

Keywords

lead alloys; optoelectronic devices; packaging; reflow soldering; tin alloys; wetting; 10 s; 220 degC; PbSn; alignment accuracy; background vibration; fluxless soldering; formic acid vapor; joint height; joint self-aligning process; reflow chamber; self-alignment characteristics; vapor concentration; Assembly; Cleaning; Gases; Optical devices; Optical modulation; Silicon; Soldering; Solvents; Space technology; Tin;

fLanguage

English

Journal_Title

Advanced Packaging, IEEE Transactions on

Publisher

ieee

ISSN

1521-3323

Type

jour

DOI

10.1109/6040.803451

Filename

803451