Aging, growth of whisker, and thermal damage are the major issues when soldering electronic components. The authors present investigations to determine the influence of process times on the threshold temperature leading to thermal damage in epoxy-based printed circuit boards (PCBs). Experimentally verified numerical modeling was used to determine the temperature distribution at the interface of copper and the epoxy resin. The results show that the threshold temperature significantly increases with decreasing process times. With interaction times shorter than 5 ms, the threshold temperatures are found to be 900 K higher than the ones specified for longer heating times according to the data sheet for PCBs with FR4 epoxy resin.

Topics
Electrical components, Electronic devices, Printed circuit board, Thermal conductivity, Thermodynamic properties, Welding, Numerical methods, Laser applications
1.
R. J.
 
Klein-Wassink
 and
B. F.
 
Müller
,
Weichlöten in der Elektronik
(
Lezue Verlag; Leuze, Saulgau
,
Württemberg
,
1991
).
Google Scholar
 
2.
C. E.
 
Reitlinger
, “
Entwicklung alternativer bleifreier Lote für die Mikroverbindungstechnik
,” Bayreuth, Univ. Diss. 2000 (
Utz Wiss
,
München
,
2001
).
Google Scholar
 
3.
B.
 
Mehlmann
,
E.
 
Gehlen
,
A.
 
Olowinsky
 et al., “
Laser micro welding for ribbon bonding
,”
Phys. Procedia
 
56
,
776
–
781
(
2014
).
https://doi.org/10.1016/j.phpro.2014.08.085
Google Scholar
Crossref
Search ADS
 
4.
S.
 
Britten
, “
Bauteilschonende Verbindungstechnik auf Metallisierungen durch moduliertes Laserstrahlschweißen
,” in
Joining of Thermally-Sensitive Components with Metallization by Modulated Laser Beam Welding
(
Apprimus Verlag
,
Aachen
,
2017
).
Google Scholar
 
5.
A.
 
Olowinski
,
A.
 
Boglea
, and
J.
 
Gedicke
, “
Innovative laser welding
,”
Micro Mater. Processes
 
3
,
48
–
51
(
2008
). last checked 14.05.2019
Google Scholar
 
6.
A.
 
Heider
,
P.
 
Stritt
,
A.
 
Hess
 et al., “
Process stabilization at welding copper by laser power modulation
,”
Phys. Procedia
 
12
,
81
–
87
(
2011
).
https://doi.org/10.1016/j.phpro.2011.03.011
Google Scholar
Crossref
Search ADS
 
7.
A.
 
Hess
,
A.
 
Heider
,
R.
 
Schuster
 et al., “
Benefits from combining laser beams with different wavelength for copper welding
,” in ICALEO 2010, International Congress on Laser Materials Processing and Nanomanufacturing, Anaheim, CA, 26–30 September 2010 (Laserinstitute of America, 2010), pp. 540–546.
8.
F.
 
Otte
,
S.
 
Pamin
,
J.
 
Hermsdorf
,
D.
 
Kracht
, and
R.
 
Kling
, “
Enhancement of process stability for laser spot micro welding by using 532 nm radiation,
” in
Proceeding of LAMP
(
2009
).
9.
A.
 
Blom
,
P.
 
Dunias
,
P.
 
van Engen
,
W.
 
Hoving
, and
J.
 
de Kramer
, “
Process spread reduction of laser microspot welding of thin copper parts using real-time control
,” in Photon Processing in Microelectronics and Photonics II (International Society for Optics and Photonics, 2003), Vol. 4977
10.
C.
 
Rüttimann
,
U.
 
Dürr
, and
A.
 
Moalem
, “
Reliable laser micro-welding of copper,
” in ICALEO 2010, International Congress on Laser Materials Processing and Nanomanufacturing, Anaheim, CA, USA, 26–30 September 2010 (Laser Institute of America, 2010), pp. 95–100.
11.
P.
 
Stritt
,
C.
 
Hagenlocher
,
C.
 
Kizler
 et al., “
Laser spot welding of copper-aluminum joints using a pulsed dual wavelength laser at 532 and 1064 nm
,”
Phys. Procedia
 
56
,
759
–
767
(
2014
).
https://doi.org/10.1016/j.phpro.2014.08.083
Google Scholar
Crossref
Search ADS
 
12.
M. S.
 
Zediker
,
M. J.
 
Silva Sa
,
M.
 
Finuf
 et al., “
Blue laser diode (450 nm) system for welding copper
,
”
Proc. SPIE
 
10514
,
1051407
(
2018
).
Google Scholar
 
13.
E.-M.
 
Dold
,
E.
 
Kaiser
,
K.
 
Klausmann
,
S.
 
Pricking
,
S.
 
Zaske
, and
R.
 
Brockmann
, “
High-performance welding of copper with green multi-kW continuous wave disk lasers,
” in High-Power Laser Materials Processing: Applications, Diagnostics, and Systems VIII (International Society for Optics and Photonics, 2019), Vol. 10911, p. 109110U.
14.
W.-S.
 
Chung
,
A.
 
Olowinsky
, and
A.
 
Gillner
, “
Process studies on copper laser beam welding over gap by using disc laser at green wavelength
,”
J. Adv. Joining Process.
 
1
,
100009
(
2020
).
https://doi.org/10.1016/j.jajp.2020.100009
Google Scholar
Crossref
Search ADS
 
15.
Isola Group
,
DE104 Data Sheet
(
Isola Group
,
Chandler, AZ
,
2019
).
16.
F.
 
Fetzer
,
P.
 
Stritt
,
P.
 
Berger
 et al., “
Fast numerical method to predict the depth of laser welding
,”
J. Laser Appl.
 
2
,
22012
(
2017
).
https://doi.org/10.2351/1.4983152
Google Scholar
Crossref
Search ADS
 
17.
F.
 
Rösler
 and
D.
 
Brüggemann
, “
Shell-and-tube type latent heat thermal energy storage: Numerical analysis and comparison with experiments
,”
Heat Mass Transfer
 
8
,
1027
–
1033
(
2011
).
https://doi.org/10.1007/s00231-011-0866-9
Google Scholar
Crossref
Search ADS
 
18.
A. E.
 
Siegman
,
Lasers
(
University Science Books
,
Mill Valley, CA
,
1986
).
Google Scholar
 
19.
John R.
 
Rumble
,
David R.
 
Lide
, and
Thomas J.
 
Bruno
,
CRC Handbook of Chemistry and Physics: A Ready-Reference Book of Chemical and Physical Data
, 99th ed. (
CRC
,
Boca Raton
,
2018
).
Google Scholar
 
© 2020 Author(s).
2020
Author(s)
You do not currently have access to this content.