Pb-free soldering and the use of electrically conducive adhesives in the electronics industry are a segment of the global trend towards a lead-free environment. In comparison to lead-free solders, current commercial isotropic conductive adhesives are characterized by lower conductivity and need much more time for curing. Usually, a few minutes at 150°C are enough only for precuring. In this paper we describe the developed family of formulations with a curing time of several seconds at 150°C. There are single-component formulations, solvent-free type, prepared in a special way on the base of the common, accessible resins. They have very convenient handling properties; e.g., no drying on open screen during printing process. Viscosity depends on the resin and may be intentionally changed. Shelf life for all these formulations is about 12months at room temperature in closed containers. Refrigeration is not necessary. Unfortunately, the material needs the highest quality and purity of electronic grade silver fillers. The total permitted level of impurities is estimated as less than 10ppm. However, this is, rather, an advantage of the silver-filled adhesives.

2.
Felba
,
J.
, 2002, “
Electrical Properties of Adhesive Joints
,”
European Microelectronics Packaging and Interconnections Symposium
,
Cracow
, pp.
6
11
.
3.
Felba
,
J.
,
Friedel
,
K.
,
Guenthner
,
B.
,
Mościcki
,
A.
, and
Schäfer
,
H.
, 2002, “
The Influence of Filler Particle Shapes on Adhesive Joints in Microwave Applications
,”
2nd International IEEE Conf. on Polymers and Adhesives in Microelectronic and Photonics
,
Zalaegerszeg
, pp.
1
6
;
Liu
,
J.
,
Conductive Adhesives for Electronic Packaging
,
Electrochemical Publications Ltd.
4.
Wong
,
C. P.
, and
Daoqiang
,
L.
, 2000, “
Recent Advances on Electrically Conductive Adhesives for Electronics Applications
,”
4th International Conf. on Adhesives Joining & Coating Technology in Electronic Manufacturing
,
Espoo
, pp.
121
128
.
5.
Haberland
,
J.
,
Kallmayer
,
Ch.
,
Aschenbrenner
,
R.
, and
Reichl
,
H.
, 2001, “
Fundamental Studies of Isotropic Conductive Adhesives Focused on the Current Loadability of ICA for Flip Chip Application
,”
1st International IEEE Conf. on Polymers and Adhesives in Microelectronics and Photonics
,
Potsdam
, pp.
185
195
.
6.
Morris
,
J. E.
,
Anderssohn
,
F.
,
Kudtarkar
,
S.
, and
Loos
,
E.
, 2001, “
Reliability Studies of an Isotropic Electrically Conductive Adhesive
,”
1st International IEEE Conf. on Polymers and Adhesives in Microelectronics and Photonics
,
Potsdam
, pp.
61
69
.
7.
Liu
,
J.
, 2001, “
Life Time Prediction of Anisotropic Conductive Adhesive Joints During Temperature Cycling for Electronics Interconnect
,”
1st International IEEE Conf. on Polymers and Adhesives in Microelectronics and Photonics
,
Potsdam
, pp.
209
212
.
8.
Li
,
L.
, and
Morris
,
J. E.
, 1988, “
Curing of Isotropic Electrically Conductive Adhesives
” in “
Conductive Adhesives for Electronics Packaging
,”
J.
Liu
, ed.,
Electrochemical Publications Ltd
.
9.
Ross
,
P. J.
, 1988, “
Taguchi Techniques for Quality Engineering
,”
McGraw-Hill
, New York.
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