Browse Prior Art Database

Wire Bonded Captive Accounting Card Assembly Technique

IP.com Disclosure Number: IPCOM000037530D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Bosley, R: AUTHOR [+5]

Abstract

A smart card assembly technique provides a flexible card using highly automated fabrication methods and low cost materials.

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Wire Bonded Captive Accounting Card Assembly Technique

A smart card assembly technique provides a flexible card using highly automated fabrication methods and low cost materials.

Current smart card fabrication methods utilize protective enclosures for chips and bond sites which are assembled separately and then laminated into a card structure. The protective enclosures limit card flexibility over a large area and create a potential for card rupture or craze at the enclosure interfaces during normal handling or flexing. Long lead time tape automated bonding (TAB) equipment and protective enclosure tool sets are inflexible and not easily adapted to new or alternate chip or circuit introductions. Engineering changes (EC's) and jumper capability are unreliable or impossible to accommodate.

In order to fabricate a flexible smart card, prepunched sheets are laminated together and a single layer circuit construction is employed. Multiple layers of prepunched polyester material are laminated together to create areas for chip adhesion, wire bond termination cavities and chip isolation. The card layers themselves provide a captive chip environment when laminated to chip surfaces while wire bond cavity areas, optionally filled with an insulating grease, fully protect all interconnections. Circuit etching of copper is utilized to define wire bonding and chip mounting sites. These sites also serve as heat transfer windows. Programmable high speed wire bonding equipment is use...