Reflow soldering with nitrogen injection is simulated. Soldering is performed in a process oven that is equipped with porous panel heaters through which air or nitrogen is introduced to the reflow environment. The injected gas is introduced selectively through top or bottom infrared heaters in order to dampen temperature fluctuations which can be established by thermal buoyancy forces in the oven gas. The heat transfer processes are simulated using an existing, general numerical model that accounts for multimode effects, and is capable of predicting large and small scale thermal and species concentration phenomena. With selective injection, it is shown that high frequency convective heating and/or cooling of the card assembly can be eliminated, and oxygen concentrations in the reflow section can be controlled to low levels.

1.
Beckermann
C.
, and
Smith
T. F.
,
1993
, “
Incorporation of Internal Surface Radiant Exchange in the Finite Volume Method
,”
Numerical Heat Transfer
, Part B, Vol.
23
, pp.
127
133
.
2.
Brown
K.
,
Freitag
B.
, and
Jopek
S.
,
1993
, “
Inert Soldering of Discrete Components
,”
Circuits Assembly
, Vol.
4
, pp.
50
53
.
3.
Eftychiou, M. A., 1992, “Thermal Modeling of the Infrared Solder Reflow Process,” M.S. thesis, The University of Texas at Austin, Austin, TX.
4.
Eftychiou
M. A.
,
Bergman
T. L.
, and
Masada
G. Y.
,
1992
, “
Thermal Effects During Infrared Solder Reflow-Part II. A Model of the Reflow Process
,”
ASME JOURNAL OF ELECTRONIC PACKAGING
, Vol.
114
, pp.
48
54
.
5.
Eftychiou
M. A.
,
Bergman
T. L.
, and
Masada
G. Y.
,
1993
, “
A Detailed Thermal Model of the Infrared Reflow Soldering Process
,”
ASME JOURNAL OF ELECTRONIC PACKAGING
, Vol.
115
, pp.
55
62
.
6.
Lea, C., 1988, A Scientific Guide to Surface Mount Technology, Electrochemical Publications Limited, Ayr, Scotland.
7.
Son, Y. S., Bergman, T. L., and Masada, G. Y., 1993, “Detailed Card Assembly Thermal Response during Infrared Reflow Soldering,” Advances in Electronic Packaging, P. A. Engel and W. T. Chen, eds. ASME, New York, Vol. 4-2, pp. 575–581.
8.
Son, Y. S., 1994, “Multimode Heat Transfer During Reflow Soldering of Electronics Assemblies,” PhD thesis, The University of Texas at Austin, Austin, TX.
9.
Strauss, R., 1994, Surface Mount Technology, Butterworth-Heinemann Ltd, Oxford.
10.
Whalley
D. C.
,
Ogunjimi
A.
,
Conway
P. P.
, and
Williams
D. J.
,
1992
, “
The Process Modelling of the Infrared Reflow Soldering of Printed Circuit Board Assemblies
,”
Journal of Electronics Manufacturing
, Vol.
2
, pp.
23
29
.
This content is only available via PDF.
You do not currently have access to this content.