Characterization of anisotropic conducting adhesive used as a flex-to-card interconnection

Author

Prabhakumar, Ananth ; Constable, J.H.

Author_Institution

Dept. of Electr. Eng., State Univ. of New York, Binghamton, NY, USA

fYear

2001

fDate

2001

Firstpage

580

Lastpage

585

Abstract

Commercial anisotropic conducting adhesive (ACA) film was used as a solder substitute to interconnect the polyimide flexible circuit from a flat panel display to the FR4 circuit card. The electrical interconnection properties of these bonds were measured shortly after bonding and after subjecting the bonded assemblies to thermal cycling and temperature and humidity. Two bond geometries were investigated, one with an area of 0.409 mm² and the other with an area of 1.29 mm². The effect of bonding temperature and pressure on the bond thickness, number of trapped particles, and resistance was investigated. Over the range of bonding pressures, a systematic variation in the average bond thickness was found, but no variation was found in the number of particles in the bond, or the resistance. Using a technique to separate the a-spot constriction resistance from the bulk resistance, observations were made of the change in these two components of the total resistance as the specimens were aged. The change in the two types of resistance were monitored both in thermal cycling, and as a function of time for aging at 85°C and 79% relative humidity (RH). The thermal electric voltage at the a-spot contact was also monitored as the a-spot was heated with excess electrical current

Keywords

adhesives; ageing; conducting polymers; filled polymers; flat panel displays; liquid crystal displays; packaging; 85 degC; FR4 circuit card; a-spot constriction resistance; aging; anisotropic conducting adhesive; bond geometries; bond thickness; bonded assemblies; electrical interconnection properties; excess electrical current; flat panel display; flex-to-card interconnection; polyimide flexible circuit; relative humidity; thermal cycling; thermal electric voltage; trapped particles; Aging; Anisotropic magnetoresistance; Bonding; Electric resistance; Flexible printed circuits; Humidity; Integrated circuit interconnections; Monitoring; Temperature; Thermal resistance;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Components and Technology Conference, 2001. Proceedings., 51st

Conference_Location

Orlando, FL

ISSN

0569-5503

Print_ISBN

0-7803-7038-4

Type

conf

DOI

10.1109/ECTC.2001.927787

Filename

927787