The effect of reflow process on the contact resistance and reliability of anisotropic conductive film interconnection for flip chip on flex applications

The work presented in this paper focuses on the effect of reflow process on the contact resistance and reliability of anisotropic conductive film (ACF) interconnection. The contact resistance of ACF interconnection increases after reflow process due to the decrease in contact area of the conducting particles between the mating I/O pads. However, the relationship between the contact resistance and bonding parameters of the ACF interconnection with reflow treatment follows the similar trend to that of the as-bonded (i.e. without reflow) ACF interconnection. The contact resistance increases as the peak temperature of reflow profile increases. Nearly 40% of the joints were found to be open after reflow with 260 °C peak temperature. During the reflow process, the entrapped (between the chip and substrate) adhesive matrix tries to expand much more than the tiny conductive particles because of the higher coefficient of thermal expansion, the induced thermal stress will try to lift the bump from the pad and decrease the contact area of the conductive path and eventually, leading to a complete loss of electrical contact. In addition, the environmental effect on contact resistance such as high temperature/humidity aging test was also investigated. Compared with the ACF interconnections with Ni/Au bump, higher thermal stress in the Z-direction is accumulated in the ACF interconnections with Au bump during the reflow process owing to the higher bump height, thus greater loss of contact area between the particles and I/O pads leads to an increase of contact resistance and poorer reliability after reflow.

‘The Pinocchio Effect’ – when managing the brand creation process, across cultures

In global marketing and international management, the fields of Branding and Culture are well discussed as separate disciplines; within both academia and industry. However, there appears to be limited supporting literature, examining brands and culture as a collective discipline. In addition, environmental factors such as ethnicity, nationality and religion are also seen to play a significant role. This in itself adds to the challenges encountered, by those looking to critically apply learning and frameworks, to any information gathered. In the first instance, this paper tries to bring aspects together from Branding and Culture and in doing so, aims to find linkages between the two. The main purpose of this paper is to distil current brand thinking and explore what impact cross-cultural, cross-national, and ethnic interactions have on a brand’s creation. The position of the authors is that without further understanding in this field, a brand will experience what has been termed by them as the ‘Pinocchio Effect’. Pinocchio was a puppet who longed to become a real human being; but sadly encountered difficulties. The conclusion presented is that the critical long-term success of a brand lies in three areas: how it is created; the subsequent associated perceptions; and more specifically in the reality of the relationships that it enjoys. Collectively these processes necessitate an appraisal of connecting strategic management procedures and thinking. Finally, this paper looks into proposing future methods for brand evaluation and strategic management. The aim is to stimulate further thinking in a field; which transcends national, ethnic and cultural boundaries - in the interests of developing new insight, and to provide a platform for marketers to develop more effective communications.