APPARATUS FOR TESTING ADHESION STRENGTH BETWEEN A SMART CARD MODULE AND THE CARD BODY
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2002-Jul-16
Modules used in smart cards are glued inside a milled or molded cavity. Two gluing processes are typically used - I) hot process using a hot melt glue film that is bonded with heat and pressure, and 2) cold process using Cyano-accrylate glue that is bonded with pressure only. In both cases, the strength of the bond is critical as it determines the life of the card in the field. Insufficient bond strength will result in the module lift- ing off the card surface and may even result in the module falling off. In contacted smart cards, bond strength of 25 lbs. is considered acceptable. The card is functional even when the module starts to lift off in the corners when subjected to bending. In case of combination smart cards, joint strength of at least 2X that of contacted smart cards is essential for maintain- ing the antenna connection and ensuring that the con- tactless operation is functional. Separation of the mod- ule from the card surface (particularly in the comers) will stress the antenna connection and may result in breaking the joint and thus causing an open circuit. Current bond strength testing methods have been designed with smart card applications in mind and are not suitable for combination smart card applications.