Reliability studies of an isotropic electrically conductive adhesive

Isotropic conductive adhesives in electronics

“…the increased/decreased conductance parallel/ perpendicular to current flow. Morris et al (2001) show the resistance of a z-axis contact as it is mechanically thinned, with a sharp drop in resistivity when the aligned surface layer is removed.…”

“…It is necessary to separate contact resistance and the bulk composite resistivity in order to interpret physical effects on each, independently (see below), by the subtraction of the common four-terminal measurement, which removes test lead and contact effects, from a three-terminal measurement which includes one contact in the test current path (Morris et al, 2001;Klosterman et al, 1998).…”

“…The ICA resistance under test is typically of the same order as PWB track resistances (Morris et al, 2001;Kulkarni and Morris, 2003), and one should make some simple estimates of all resistances in the test set-up to determine contact thicknesses to avoid current crowding. Because ICA z-axis resistances are small, many experimental results in the literature have been obtained by x-axis measurements, i.e.…”

“…When investigating plasma surface treatments, it was discovered that vacuum exposure of the iCA prior to cure, improved contact adhesion significantly, by elimination of bubbles from the material (Morris et al, 2001). If cure proceeds too quickly, the organic solvents used to control viscosity for printing or dispensing cannot escape, and become entrapped in the epoxy as bubbles, and bubbles at the contact interface have also been correlated with weak ACF adhesion (Kim et al, 2006).…”

Electrically Conductive Adhesives

“…Adhesives are preferable whenever high elasticity is needed to compensate for thermal expansion mismatch between substrate and component body [19][20][21][22]. However, compared to soldering, electrically conductive adhesive technology is still in its infancy [23,24]. Two critical issues of conductive adhesives for surface mount applications are the contact resistance shift during lifetime and a low impact performance [25].…”