Credit card sized integrated circuit integrated circuit cards are commercially available and find utility in numerous electronic systems. In personal computers they supplement or replace floppy disks by carrying software programs and data. Integrated circuit cards are connected to the computer's internal logic by insertion through an opening in the side of the computer to mate with a socket contained within the computer. Portable personal computers, notebook computers, and pocket diaries particularly find integrated circuit cards convenient because they avoid the need for the expense, power requirements, bulk, and weight of a disk drive; the integrated circuit card needs only an electrical connector and minimal structural, support.
Facsimile and copy machines can use an integrated circuit card to store data related to usage control. Typewriters and printers can use an integrated circuit card to store desired memory fonts. Word processors can use an integrated circuit card to store text. Hand-held terminals can use integrated circuit cards to store inventory control information. Electronic cash registers can use integrated circuit cards to store price information. Controllable machinery can use integrated circuit cards to store automation control information. Programmable controllers can use integrated circuit cards to store process control data. Electronic game systems can use integrated circuit cards to store the specifics of games to be enacted on TV screens by the players.
Other areas that can benefit from the use of integrated circuit cards include bulk data acquisition such as in music and photography, where the desired song or picture is stored in the memory devices of the card.
Presently available integrated circuit cards typically include one or more plastic-encapsulated or other types of integrated circuits solder attached to connection stripes or spots on a printed wire board. A connector is solder attached to metal lines which are formed on the printed wire board and extend to one edge of the board. The connector connects external power, signal, and ground lines to circuitry in the card. An external shell or encasement surrounds the printed wire board/integrated circuit/connector assembly. The encasement typically has top and bottom frames formed from molded plastic and bonded together along an outer edge to define an interior chamber in which the printed wire board is located. The top and bottom frames have ribs which contact and securely hold the printed wire board and connector in place. Top and bottom metal plates are bonded to the top and bottom frames, respectively, and cover openings in the top and bottom frames.
The use of a plastic frame adds significantly to the complexity, tooling costs, and tooling turn around time in integrated circuit card construction. This is due to the fact that the manufacture of a plastic frame requires the use of a mold. Whenever the size of the printed wire board or the number, location, or size of the semiconductor devices on the printed wire board is changed, a new plastic frame that will accommodate the changes is required. The fabrication of the mold for the new frame is extremely time consuming and expensive. As a result, the time and expense incurred in producing integrated circuit cards incorporating even minor design changes are significant.
The use of a molded plastic frame is also a major source of problems during assembly of the integrated circuit card due to the fact that molded plastic frames are easily bent and often have surface irregularities introduced during the molding process which prevent all integrated circuit card parts from fitting together properly. In addition, processes for bonding the top and bottom plastic frames together, such as ultrasonic welding, are difficult and produce integrated circuit cards having inconsistent quality.
Accordingly, a need exists for an integrated circuit integrated circuit card that can be produced quickly, is simple, inexpensive, and reliable, and does not require a plastic frame.